| // SPDX-License-Identifier: GPL-2.0-or-later |
| // SPI init/core code |
| // |
| // Copyright (C) 2005 David Brownell |
| // Copyright (C) 2008 Secret Lab Technologies Ltd. |
| |
| #include <linux/kernel.h> |
| #include <linux/device.h> |
| #include <linux/init.h> |
| #include <linux/cache.h> |
| #include <linux/dma-mapping.h> |
| #include <linux/dmaengine.h> |
| #include <linux/mutex.h> |
| #include <linux/of_device.h> |
| #include <linux/of_irq.h> |
| #include <linux/clk/clk-conf.h> |
| #include <linux/slab.h> |
| #include <linux/mod_devicetable.h> |
| #include <linux/spi/spi.h> |
| #include <linux/spi/spi-mem.h> |
| #include <linux/of_gpio.h> |
| #include <linux/gpio/consumer.h> |
| #include <linux/pm_runtime.h> |
| #include <linux/pm_domain.h> |
| #include <linux/property.h> |
| #include <linux/export.h> |
| #include <linux/sched/rt.h> |
| #include <uapi/linux/sched/types.h> |
| #include <linux/delay.h> |
| #include <linux/kthread.h> |
| #include <linux/ioport.h> |
| #include <linux/acpi.h> |
| #include <linux/highmem.h> |
| #include <linux/idr.h> |
| #include <linux/platform_data/x86/apple.h> |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/spi.h> |
| EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start); |
| EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop); |
| |
| #include "internals.h" |
| |
| static DEFINE_IDR(spi_master_idr); |
| |
| static void spidev_release(struct device *dev) |
| { |
| struct spi_device *spi = to_spi_device(dev); |
| |
| spi_controller_put(spi->controller); |
| kfree(spi->driver_override); |
| kfree(spi); |
| } |
| |
| static ssize_t |
| modalias_show(struct device *dev, struct device_attribute *a, char *buf) |
| { |
| const struct spi_device *spi = to_spi_device(dev); |
| int len; |
| |
| len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); |
| if (len != -ENODEV) |
| return len; |
| |
| return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); |
| } |
| static DEVICE_ATTR_RO(modalias); |
| |
| static ssize_t driver_override_store(struct device *dev, |
| struct device_attribute *a, |
| const char *buf, size_t count) |
| { |
| struct spi_device *spi = to_spi_device(dev); |
| const char *end = memchr(buf, '\n', count); |
| const size_t len = end ? end - buf : count; |
| const char *driver_override, *old; |
| |
| /* We need to keep extra room for a newline when displaying value */ |
| if (len >= (PAGE_SIZE - 1)) |
| return -EINVAL; |
| |
| driver_override = kstrndup(buf, len, GFP_KERNEL); |
| if (!driver_override) |
| return -ENOMEM; |
| |
| device_lock(dev); |
| old = spi->driver_override; |
| if (len) { |
| spi->driver_override = driver_override; |
| } else { |
| /* Empty string, disable driver override */ |
| spi->driver_override = NULL; |
| kfree(driver_override); |
| } |
| device_unlock(dev); |
| kfree(old); |
| |
| return count; |
| } |
| |
| static ssize_t driver_override_show(struct device *dev, |
| struct device_attribute *a, char *buf) |
| { |
| const struct spi_device *spi = to_spi_device(dev); |
| ssize_t len; |
| |
| device_lock(dev); |
| len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : ""); |
| device_unlock(dev); |
| return len; |
| } |
| static DEVICE_ATTR_RW(driver_override); |
| |
| #define SPI_STATISTICS_ATTRS(field, file) \ |
| static ssize_t spi_controller_##field##_show(struct device *dev, \ |
| struct device_attribute *attr, \ |
| char *buf) \ |
| { \ |
| struct spi_controller *ctlr = container_of(dev, \ |
| struct spi_controller, dev); \ |
| return spi_statistics_##field##_show(&ctlr->statistics, buf); \ |
| } \ |
| static struct device_attribute dev_attr_spi_controller_##field = { \ |
| .attr = { .name = file, .mode = 0444 }, \ |
| .show = spi_controller_##field##_show, \ |
| }; \ |
| static ssize_t spi_device_##field##_show(struct device *dev, \ |
| struct device_attribute *attr, \ |
| char *buf) \ |
| { \ |
| struct spi_device *spi = to_spi_device(dev); \ |
| return spi_statistics_##field##_show(&spi->statistics, buf); \ |
| } \ |
| static struct device_attribute dev_attr_spi_device_##field = { \ |
| .attr = { .name = file, .mode = 0444 }, \ |
| .show = spi_device_##field##_show, \ |
| } |
| |
| #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \ |
| static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \ |
| char *buf) \ |
| { \ |
| unsigned long flags; \ |
| ssize_t len; \ |
| spin_lock_irqsave(&stat->lock, flags); \ |
| len = sprintf(buf, format_string, stat->field); \ |
| spin_unlock_irqrestore(&stat->lock, flags); \ |
| return len; \ |
| } \ |
| SPI_STATISTICS_ATTRS(name, file) |
| |
| #define SPI_STATISTICS_SHOW(field, format_string) \ |
| SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \ |
| field, format_string) |
| |
| SPI_STATISTICS_SHOW(messages, "%lu"); |
| SPI_STATISTICS_SHOW(transfers, "%lu"); |
| SPI_STATISTICS_SHOW(errors, "%lu"); |
| SPI_STATISTICS_SHOW(timedout, "%lu"); |
| |
| SPI_STATISTICS_SHOW(spi_sync, "%lu"); |
| SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu"); |
| SPI_STATISTICS_SHOW(spi_async, "%lu"); |
| |
| SPI_STATISTICS_SHOW(bytes, "%llu"); |
| SPI_STATISTICS_SHOW(bytes_rx, "%llu"); |
| SPI_STATISTICS_SHOW(bytes_tx, "%llu"); |
| |
| #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \ |
| SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \ |
| "transfer_bytes_histo_" number, \ |
| transfer_bytes_histo[index], "%lu") |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535"); |
| SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+"); |
| |
| SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu"); |
| |
| static struct attribute *spi_dev_attrs[] = { |
| &dev_attr_modalias.attr, |
| &dev_attr_driver_override.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group spi_dev_group = { |
| .attrs = spi_dev_attrs, |
| }; |
| |
| static struct attribute *spi_device_statistics_attrs[] = { |
| &dev_attr_spi_device_messages.attr, |
| &dev_attr_spi_device_transfers.attr, |
| &dev_attr_spi_device_errors.attr, |
| &dev_attr_spi_device_timedout.attr, |
| &dev_attr_spi_device_spi_sync.attr, |
| &dev_attr_spi_device_spi_sync_immediate.attr, |
| &dev_attr_spi_device_spi_async.attr, |
| &dev_attr_spi_device_bytes.attr, |
| &dev_attr_spi_device_bytes_rx.attr, |
| &dev_attr_spi_device_bytes_tx.attr, |
| &dev_attr_spi_device_transfer_bytes_histo0.attr, |
| &dev_attr_spi_device_transfer_bytes_histo1.attr, |
| &dev_attr_spi_device_transfer_bytes_histo2.attr, |
| &dev_attr_spi_device_transfer_bytes_histo3.attr, |
| &dev_attr_spi_device_transfer_bytes_histo4.attr, |
| &dev_attr_spi_device_transfer_bytes_histo5.attr, |
| &dev_attr_spi_device_transfer_bytes_histo6.attr, |
| &dev_attr_spi_device_transfer_bytes_histo7.attr, |
| &dev_attr_spi_device_transfer_bytes_histo8.attr, |
| &dev_attr_spi_device_transfer_bytes_histo9.attr, |
| &dev_attr_spi_device_transfer_bytes_histo10.attr, |
| &dev_attr_spi_device_transfer_bytes_histo11.attr, |
| &dev_attr_spi_device_transfer_bytes_histo12.attr, |
| &dev_attr_spi_device_transfer_bytes_histo13.attr, |
| &dev_attr_spi_device_transfer_bytes_histo14.attr, |
| &dev_attr_spi_device_transfer_bytes_histo15.attr, |
| &dev_attr_spi_device_transfer_bytes_histo16.attr, |
| &dev_attr_spi_device_transfers_split_maxsize.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group spi_device_statistics_group = { |
| .name = "statistics", |
| .attrs = spi_device_statistics_attrs, |
| }; |
| |
| static const struct attribute_group *spi_dev_groups[] = { |
| &spi_dev_group, |
| &spi_device_statistics_group, |
| NULL, |
| }; |
| |
| static struct attribute *spi_controller_statistics_attrs[] = { |
| &dev_attr_spi_controller_messages.attr, |
| &dev_attr_spi_controller_transfers.attr, |
| &dev_attr_spi_controller_errors.attr, |
| &dev_attr_spi_controller_timedout.attr, |
| &dev_attr_spi_controller_spi_sync.attr, |
| &dev_attr_spi_controller_spi_sync_immediate.attr, |
| &dev_attr_spi_controller_spi_async.attr, |
| &dev_attr_spi_controller_bytes.attr, |
| &dev_attr_spi_controller_bytes_rx.attr, |
| &dev_attr_spi_controller_bytes_tx.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo0.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo1.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo2.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo3.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo4.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo5.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo6.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo7.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo8.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo9.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo10.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo11.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo12.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo13.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo14.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo15.attr, |
| &dev_attr_spi_controller_transfer_bytes_histo16.attr, |
| &dev_attr_spi_controller_transfers_split_maxsize.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group spi_controller_statistics_group = { |
| .name = "statistics", |
| .attrs = spi_controller_statistics_attrs, |
| }; |
| |
| static const struct attribute_group *spi_master_groups[] = { |
| &spi_controller_statistics_group, |
| NULL, |
| }; |
| |
| void spi_statistics_add_transfer_stats(struct spi_statistics *stats, |
| struct spi_transfer *xfer, |
| struct spi_controller *ctlr) |
| { |
| unsigned long flags; |
| int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1; |
| |
| if (l2len < 0) |
| l2len = 0; |
| |
| spin_lock_irqsave(&stats->lock, flags); |
| |
| stats->transfers++; |
| stats->transfer_bytes_histo[l2len]++; |
| |
| stats->bytes += xfer->len; |
| if ((xfer->tx_buf) && |
| (xfer->tx_buf != ctlr->dummy_tx)) |
| stats->bytes_tx += xfer->len; |
| if ((xfer->rx_buf) && |
| (xfer->rx_buf != ctlr->dummy_rx)) |
| stats->bytes_rx += xfer->len; |
| |
| spin_unlock_irqrestore(&stats->lock, flags); |
| } |
| EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats); |
| |
| /* modalias support makes "modprobe $MODALIAS" new-style hotplug work, |
| * and the sysfs version makes coldplug work too. |
| */ |
| |
| static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, |
| const struct spi_device *sdev) |
| { |
| while (id->name[0]) { |
| if (!strcmp(sdev->modalias, id->name)) |
| return id; |
| id++; |
| } |
| return NULL; |
| } |
| |
| const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) |
| { |
| const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); |
| |
| return spi_match_id(sdrv->id_table, sdev); |
| } |
| EXPORT_SYMBOL_GPL(spi_get_device_id); |
| |
| static int spi_match_device(struct device *dev, struct device_driver *drv) |
| { |
| const struct spi_device *spi = to_spi_device(dev); |
| const struct spi_driver *sdrv = to_spi_driver(drv); |
| |
| /* Check override first, and if set, only use the named driver */ |
| if (spi->driver_override) |
| return strcmp(spi->driver_override, drv->name) == 0; |
| |
| /* Attempt an OF style match */ |
| if (of_driver_match_device(dev, drv)) |
| return 1; |
| |
| /* Then try ACPI */ |
| if (acpi_driver_match_device(dev, drv)) |
| return 1; |
| |
| if (sdrv->id_table) |
| return !!spi_match_id(sdrv->id_table, spi); |
| |
| return strcmp(spi->modalias, drv->name) == 0; |
| } |
| |
| static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) |
| { |
| const struct spi_device *spi = to_spi_device(dev); |
| int rc; |
| |
| rc = acpi_device_uevent_modalias(dev, env); |
| if (rc != -ENODEV) |
| return rc; |
| |
| return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); |
| } |
| |
| static int spi_probe(struct device *dev) |
| { |
| const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
| struct spi_device *spi = to_spi_device(dev); |
| int ret; |
| |
| ret = of_clk_set_defaults(dev->of_node, false); |
| if (ret) |
| return ret; |
| |
| if (dev->of_node) { |
| spi->irq = of_irq_get(dev->of_node, 0); |
| if (spi->irq == -EPROBE_DEFER) |
| return -EPROBE_DEFER; |
| if (spi->irq < 0) |
| spi->irq = 0; |
| } |
| |
| ret = dev_pm_domain_attach(dev, true); |
| if (ret) |
| return ret; |
| |
| if (sdrv->probe) { |
| ret = sdrv->probe(spi); |
| if (ret) |
| dev_pm_domain_detach(dev, true); |
| } |
| |
| return ret; |
| } |
| |
| static int spi_remove(struct device *dev) |
| { |
| const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
| |
| if (sdrv->remove) { |
| int ret; |
| |
| ret = sdrv->remove(to_spi_device(dev)); |
| if (ret) |
| dev_warn(dev, |
| "Failed to unbind driver (%pe), ignoring\n", |
| ERR_PTR(ret)); |
| } |
| |
| dev_pm_domain_detach(dev, true); |
| |
| return 0; |
| } |
| |
| static void spi_shutdown(struct device *dev) |
| { |
| if (dev->driver) { |
| const struct spi_driver *sdrv = to_spi_driver(dev->driver); |
| |
| if (sdrv->shutdown) |
| sdrv->shutdown(to_spi_device(dev)); |
| } |
| } |
| |
| struct bus_type spi_bus_type = { |
| .name = "spi", |
| .dev_groups = spi_dev_groups, |
| .match = spi_match_device, |
| .uevent = spi_uevent, |
| .probe = spi_probe, |
| .remove = spi_remove, |
| .shutdown = spi_shutdown, |
| }; |
| EXPORT_SYMBOL_GPL(spi_bus_type); |
| |
| /** |
| * __spi_register_driver - register a SPI driver |
| * @owner: owner module of the driver to register |
| * @sdrv: the driver to register |
| * Context: can sleep |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| int __spi_register_driver(struct module *owner, struct spi_driver *sdrv) |
| { |
| sdrv->driver.owner = owner; |
| sdrv->driver.bus = &spi_bus_type; |
| return driver_register(&sdrv->driver); |
| } |
| EXPORT_SYMBOL_GPL(__spi_register_driver); |
| |
| /*-------------------------------------------------------------------------*/ |
| |
| /* SPI devices should normally not be created by SPI device drivers; that |
| * would make them board-specific. Similarly with SPI controller drivers. |
| * Device registration normally goes into like arch/.../mach.../board-YYY.c |
| * with other readonly (flashable) information about mainboard devices. |
| */ |
| |
| struct boardinfo { |
| struct list_head list; |
| struct spi_board_info board_info; |
| }; |
| |
| static LIST_HEAD(board_list); |
| static LIST_HEAD(spi_controller_list); |
| |
| /* |
| * Used to protect add/del operation for board_info list and |
| * spi_controller list, and their matching process |
| * also used to protect object of type struct idr |
| */ |
| static DEFINE_MUTEX(board_lock); |
| |
| /* |
| * Prevents addition of devices with same chip select and |
| * addition of devices below an unregistering controller. |
| */ |
| static DEFINE_MUTEX(spi_add_lock); |
| |
| /** |
| * spi_alloc_device - Allocate a new SPI device |
| * @ctlr: Controller to which device is connected |
| * Context: can sleep |
| * |
| * Allows a driver to allocate and initialize a spi_device without |
| * registering it immediately. This allows a driver to directly |
| * fill the spi_device with device parameters before calling |
| * spi_add_device() on it. |
| * |
| * Caller is responsible to call spi_add_device() on the returned |
| * spi_device structure to add it to the SPI controller. If the caller |
| * needs to discard the spi_device without adding it, then it should |
| * call spi_dev_put() on it. |
| * |
| * Return: a pointer to the new device, or NULL. |
| */ |
| struct spi_device *spi_alloc_device(struct spi_controller *ctlr) |
| { |
| struct spi_device *spi; |
| |
| if (!spi_controller_get(ctlr)) |
| return NULL; |
| |
| spi = kzalloc(sizeof(*spi), GFP_KERNEL); |
| if (!spi) { |
| spi_controller_put(ctlr); |
| return NULL; |
| } |
| |
| spi->master = spi->controller = ctlr; |
| spi->dev.parent = &ctlr->dev; |
| spi->dev.bus = &spi_bus_type; |
| spi->dev.release = spidev_release; |
| spi->cs_gpio = -ENOENT; |
| spi->mode = ctlr->buswidth_override_bits; |
| |
| spin_lock_init(&spi->statistics.lock); |
| |
| device_initialize(&spi->dev); |
| return spi; |
| } |
| EXPORT_SYMBOL_GPL(spi_alloc_device); |
| |
| static void spi_dev_set_name(struct spi_device *spi) |
| { |
| struct acpi_device *adev = ACPI_COMPANION(&spi->dev); |
| |
| if (adev) { |
| dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev)); |
| return; |
| } |
| |
| dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev), |
| spi->chip_select); |
| } |
| |
| static int spi_dev_check(struct device *dev, void *data) |
| { |
| struct spi_device *spi = to_spi_device(dev); |
| struct spi_device *new_spi = data; |
| |
| if (spi->controller == new_spi->controller && |
| spi->chip_select == new_spi->chip_select) |
| return -EBUSY; |
| return 0; |
| } |
| |
| static void spi_cleanup(struct spi_device *spi) |
| { |
| if (spi->controller->cleanup) |
| spi->controller->cleanup(spi); |
| } |
| |
| /** |
| * spi_add_device - Add spi_device allocated with spi_alloc_device |
| * @spi: spi_device to register |
| * |
| * Companion function to spi_alloc_device. Devices allocated with |
| * spi_alloc_device can be added onto the spi bus with this function. |
| * |
| * Return: 0 on success; negative errno on failure |
| */ |
| int spi_add_device(struct spi_device *spi) |
| { |
| struct spi_controller *ctlr = spi->controller; |
| struct device *dev = ctlr->dev.parent; |
| int status; |
| |
| /* Chipselects are numbered 0..max; validate. */ |
| if (spi->chip_select >= ctlr->num_chipselect) { |
| dev_err(dev, "cs%d >= max %d\n", spi->chip_select, |
| ctlr->num_chipselect); |
| return -EINVAL; |
| } |
| |
| /* Set the bus ID string */ |
| spi_dev_set_name(spi); |
| |
| /* We need to make sure there's no other device with this |
| * chipselect **BEFORE** we call setup(), else we'll trash |
| * its configuration. Lock against concurrent add() calls. |
| */ |
| mutex_lock(&spi_add_lock); |
| |
| status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); |
| if (status) { |
| dev_err(dev, "chipselect %d already in use\n", |
| spi->chip_select); |
| goto done; |
| } |
| |
| /* Controller may unregister concurrently */ |
| if (IS_ENABLED(CONFIG_SPI_DYNAMIC) && |
| !device_is_registered(&ctlr->dev)) { |
| status = -ENODEV; |
| goto done; |
| } |
| |
| /* Descriptors take precedence */ |
| if (ctlr->cs_gpiods) |
| spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select]; |
| else if (ctlr->cs_gpios) |
| spi->cs_gpio = ctlr->cs_gpios[spi->chip_select]; |
| |
| /* Drivers may modify this initial i/o setup, but will |
| * normally rely on the device being setup. Devices |
| * using SPI_CS_HIGH can't coexist well otherwise... |
| */ |
| status = spi_setup(spi); |
| if (status < 0) { |
| dev_err(dev, "can't setup %s, status %d\n", |
| dev_name(&spi->dev), status); |
| goto done; |
| } |
| |
| /* Device may be bound to an active driver when this returns */ |
| status = device_add(&spi->dev); |
| if (status < 0) { |
| dev_err(dev, "can't add %s, status %d\n", |
| dev_name(&spi->dev), status); |
| spi_cleanup(spi); |
| } else { |
| dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); |
| } |
| |
| done: |
| mutex_unlock(&spi_add_lock); |
| return status; |
| } |
| EXPORT_SYMBOL_GPL(spi_add_device); |
| |
| /** |
| * spi_new_device - instantiate one new SPI device |
| * @ctlr: Controller to which device is connected |
| * @chip: Describes the SPI device |
| * Context: can sleep |
| * |
| * On typical mainboards, this is purely internal; and it's not needed |
| * after board init creates the hard-wired devices. Some development |
| * platforms may not be able to use spi_register_board_info though, and |
| * this is exported so that for example a USB or parport based adapter |
| * driver could add devices (which it would learn about out-of-band). |
| * |
| * Return: the new device, or NULL. |
| */ |
| struct spi_device *spi_new_device(struct spi_controller *ctlr, |
| struct spi_board_info *chip) |
| { |
| struct spi_device *proxy; |
| int status; |
| |
| /* NOTE: caller did any chip->bus_num checks necessary. |
| * |
| * Also, unless we change the return value convention to use |
| * error-or-pointer (not NULL-or-pointer), troubleshootability |
| * suggests syslogged diagnostics are best here (ugh). |
| */ |
| |
| proxy = spi_alloc_device(ctlr); |
| if (!proxy) |
| return NULL; |
| |
| WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); |
| |
| proxy->chip_select = chip->chip_select; |
| proxy->max_speed_hz = chip->max_speed_hz; |
| proxy->mode = chip->mode; |
| proxy->irq = chip->irq; |
| strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); |
| proxy->dev.platform_data = (void *) chip->platform_data; |
| proxy->controller_data = chip->controller_data; |
| proxy->controller_state = NULL; |
| |
| if (chip->swnode) { |
| status = device_add_software_node(&proxy->dev, chip->swnode); |
| if (status) { |
| dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n", |
| chip->modalias, status); |
| goto err_dev_put; |
| } |
| } |
| |
| status = spi_add_device(proxy); |
| if (status < 0) |
| goto err_dev_put; |
| |
| return proxy; |
| |
| err_dev_put: |
| device_remove_software_node(&proxy->dev); |
| spi_dev_put(proxy); |
| return NULL; |
| } |
| EXPORT_SYMBOL_GPL(spi_new_device); |
| |
| /** |
| * spi_unregister_device - unregister a single SPI device |
| * @spi: spi_device to unregister |
| * |
| * Start making the passed SPI device vanish. Normally this would be handled |
| * by spi_unregister_controller(). |
| */ |
| void spi_unregister_device(struct spi_device *spi) |
| { |
| if (!spi) |
| return; |
| |
| if (spi->dev.of_node) { |
| of_node_clear_flag(spi->dev.of_node, OF_POPULATED); |
| of_node_put(spi->dev.of_node); |
| } |
| if (ACPI_COMPANION(&spi->dev)) |
| acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev)); |
| device_remove_software_node(&spi->dev); |
| device_del(&spi->dev); |
| spi_cleanup(spi); |
| put_device(&spi->dev); |
| } |
| EXPORT_SYMBOL_GPL(spi_unregister_device); |
| |
| static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr, |
| struct spi_board_info *bi) |
| { |
| struct spi_device *dev; |
| |
| if (ctlr->bus_num != bi->bus_num) |
| return; |
| |
| dev = spi_new_device(ctlr, bi); |
| if (!dev) |
| dev_err(ctlr->dev.parent, "can't create new device for %s\n", |
| bi->modalias); |
| } |
| |
| /** |
| * spi_register_board_info - register SPI devices for a given board |
| * @info: array of chip descriptors |
| * @n: how many descriptors are provided |
| * Context: can sleep |
| * |
| * Board-specific early init code calls this (probably during arch_initcall) |
| * with segments of the SPI device table. Any device nodes are created later, |
| * after the relevant parent SPI controller (bus_num) is defined. We keep |
| * this table of devices forever, so that reloading a controller driver will |
| * not make Linux forget about these hard-wired devices. |
| * |
| * Other code can also call this, e.g. a particular add-on board might provide |
| * SPI devices through its expansion connector, so code initializing that board |
| * would naturally declare its SPI devices. |
| * |
| * The board info passed can safely be __initdata ... but be careful of |
| * any embedded pointers (platform_data, etc), they're copied as-is. |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| int spi_register_board_info(struct spi_board_info const *info, unsigned n) |
| { |
| struct boardinfo *bi; |
| int i; |
| |
| if (!n) |
| return 0; |
| |
| bi = kcalloc(n, sizeof(*bi), GFP_KERNEL); |
| if (!bi) |
| return -ENOMEM; |
| |
| for (i = 0; i < n; i++, bi++, info++) { |
| struct spi_controller *ctlr; |
| |
| memcpy(&bi->board_info, info, sizeof(*info)); |
| |
| mutex_lock(&board_lock); |
| list_add_tail(&bi->list, &board_list); |
| list_for_each_entry(ctlr, &spi_controller_list, list) |
| spi_match_controller_to_boardinfo(ctlr, |
| &bi->board_info); |
| mutex_unlock(&board_lock); |
| } |
| |
| return 0; |
| } |
| |
| /*-------------------------------------------------------------------------*/ |
| |
| static void spi_set_cs(struct spi_device *spi, bool enable, bool force) |
| { |
| bool activate = enable; |
| |
| /* |
| * Avoid calling into the driver (or doing delays) if the chip select |
| * isn't actually changing from the last time this was called. |
| */ |
| if (!force && (spi->controller->last_cs_enable == enable) && |
| (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH))) |
| return; |
| |
| spi->controller->last_cs_enable = enable; |
| spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH; |
| |
| if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) || |
| !spi->controller->set_cs_timing) { |
| if (activate) |
| spi_delay_exec(&spi->controller->cs_setup, NULL); |
| else |
| spi_delay_exec(&spi->controller->cs_hold, NULL); |
| } |
| |
| if (spi->mode & SPI_CS_HIGH) |
| enable = !enable; |
| |
| if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) { |
| if (!(spi->mode & SPI_NO_CS)) { |
| if (spi->cs_gpiod) { |
| /* |
| * Historically ACPI has no means of the GPIO polarity and |
| * thus the SPISerialBus() resource defines it on the per-chip |
| * basis. In order to avoid a chain of negations, the GPIO |
| * polarity is considered being Active High. Even for the cases |
| * when _DSD() is involved (in the updated versions of ACPI) |
| * the GPIO CS polarity must be defined Active High to avoid |
| * ambiguity. That's why we use enable, that takes SPI_CS_HIGH |
| * into account. |
| */ |
| if (has_acpi_companion(&spi->dev)) |
| gpiod_set_value_cansleep(spi->cs_gpiod, !enable); |
| else |
| /* Polarity handled by GPIO library */ |
| gpiod_set_value_cansleep(spi->cs_gpiod, activate); |
| } else { |
| /* |
| * invert the enable line, as active low is |
| * default for SPI. |
| */ |
| gpio_set_value_cansleep(spi->cs_gpio, !enable); |
| } |
| } |
| /* Some SPI masters need both GPIO CS & slave_select */ |
| if ((spi->controller->flags & SPI_MASTER_GPIO_SS) && |
| spi->controller->set_cs) |
| spi->controller->set_cs(spi, !enable); |
| } else if (spi->controller->set_cs) { |
| spi->controller->set_cs(spi, !enable); |
| } |
| |
| if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) || |
| !spi->controller->set_cs_timing) { |
| if (!activate) |
| spi_delay_exec(&spi->controller->cs_inactive, NULL); |
| } |
| } |
| |
| #ifdef CONFIG_HAS_DMA |
| int spi_map_buf(struct spi_controller *ctlr, struct device *dev, |
| struct sg_table *sgt, void *buf, size_t len, |
| enum dma_data_direction dir) |
| { |
| const bool vmalloced_buf = is_vmalloc_addr(buf); |
| unsigned int max_seg_size = dma_get_max_seg_size(dev); |
| #ifdef CONFIG_HIGHMEM |
| const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE && |
| (unsigned long)buf < (PKMAP_BASE + |
| (LAST_PKMAP * PAGE_SIZE))); |
| #else |
| const bool kmap_buf = false; |
| #endif |
| int desc_len; |
| int sgs; |
| struct page *vm_page; |
| struct scatterlist *sg; |
| void *sg_buf; |
| size_t min; |
| int i, ret; |
| |
| if (vmalloced_buf || kmap_buf) { |
| desc_len = min_t(int, max_seg_size, PAGE_SIZE); |
| sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len); |
| } else if (virt_addr_valid(buf)) { |
| desc_len = min_t(int, max_seg_size, ctlr->max_dma_len); |
| sgs = DIV_ROUND_UP(len, desc_len); |
| } else { |
| return -EINVAL; |
| } |
| |
| ret = sg_alloc_table(sgt, sgs, GFP_KERNEL); |
| if (ret != 0) |
| return ret; |
| |
| sg = &sgt->sgl[0]; |
| for (i = 0; i < sgs; i++) { |
| |
| if (vmalloced_buf || kmap_buf) { |
| /* |
| * Next scatterlist entry size is the minimum between |
| * the desc_len and the remaining buffer length that |
| * fits in a page. |
| */ |
| min = min_t(size_t, desc_len, |
| min_t(size_t, len, |
| PAGE_SIZE - offset_in_page(buf))); |
| if (vmalloced_buf) |
| vm_page = vmalloc_to_page(buf); |
| else |
| vm_page = kmap_to_page(buf); |
| if (!vm_page) { |
| sg_free_table(sgt); |
| return -ENOMEM; |
| } |
| sg_set_page(sg, vm_page, |
| min, offset_in_page(buf)); |
| } else { |
| min = min_t(size_t, len, desc_len); |
| sg_buf = buf; |
| sg_set_buf(sg, sg_buf, min); |
| } |
| |
| buf += min; |
| len -= min; |
| sg = sg_next(sg); |
| } |
| |
| ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir); |
| if (!ret) |
| ret = -ENOMEM; |
| if (ret < 0) { |
| sg_free_table(sgt); |
| return ret; |
| } |
| |
| sgt->nents = ret; |
| |
| return 0; |
| } |
| |
| void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev, |
| struct sg_table *sgt, enum dma_data_direction dir) |
| { |
| if (sgt->orig_nents) { |
| dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir); |
| sg_free_table(sgt); |
| } |
| } |
| |
| static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) |
| { |
| struct device *tx_dev, *rx_dev; |
| struct spi_transfer *xfer; |
| int ret; |
| |
| if (!ctlr->can_dma) |
| return 0; |
| |
| if (ctlr->dma_tx) |
| tx_dev = ctlr->dma_tx->device->dev; |
| else |
| tx_dev = ctlr->dev.parent; |
| |
| if (ctlr->dma_rx) |
| rx_dev = ctlr->dma_rx->device->dev; |
| else |
| rx_dev = ctlr->dev.parent; |
| |
| list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| if (!ctlr->can_dma(ctlr, msg->spi, xfer)) |
| continue; |
| |
| if (xfer->tx_buf != NULL) { |
| ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg, |
| (void *)xfer->tx_buf, xfer->len, |
| DMA_TO_DEVICE); |
| if (ret != 0) |
| return ret; |
| } |
| |
| if (xfer->rx_buf != NULL) { |
| ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg, |
| xfer->rx_buf, xfer->len, |
| DMA_FROM_DEVICE); |
| if (ret != 0) { |
| spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, |
| DMA_TO_DEVICE); |
| return ret; |
| } |
| } |
| } |
| |
| ctlr->cur_msg_mapped = true; |
| |
| return 0; |
| } |
| |
| static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg) |
| { |
| struct spi_transfer *xfer; |
| struct device *tx_dev, *rx_dev; |
| |
| if (!ctlr->cur_msg_mapped || !ctlr->can_dma) |
| return 0; |
| |
| if (ctlr->dma_tx) |
| tx_dev = ctlr->dma_tx->device->dev; |
| else |
| tx_dev = ctlr->dev.parent; |
| |
| if (ctlr->dma_rx) |
| rx_dev = ctlr->dma_rx->device->dev; |
| else |
| rx_dev = ctlr->dev.parent; |
| |
| list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| if (!ctlr->can_dma(ctlr, msg->spi, xfer)) |
| continue; |
| |
| spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); |
| spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); |
| } |
| |
| ctlr->cur_msg_mapped = false; |
| |
| return 0; |
| } |
| #else /* !CONFIG_HAS_DMA */ |
| static inline int __spi_map_msg(struct spi_controller *ctlr, |
| struct spi_message *msg) |
| { |
| return 0; |
| } |
| |
| static inline int __spi_unmap_msg(struct spi_controller *ctlr, |
| struct spi_message *msg) |
| { |
| return 0; |
| } |
| #endif /* !CONFIG_HAS_DMA */ |
| |
| static inline int spi_unmap_msg(struct spi_controller *ctlr, |
| struct spi_message *msg) |
| { |
| struct spi_transfer *xfer; |
| |
| list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| /* |
| * Restore the original value of tx_buf or rx_buf if they are |
| * NULL. |
| */ |
| if (xfer->tx_buf == ctlr->dummy_tx) |
| xfer->tx_buf = NULL; |
| if (xfer->rx_buf == ctlr->dummy_rx) |
| xfer->rx_buf = NULL; |
| } |
| |
| return __spi_unmap_msg(ctlr, msg); |
| } |
| |
| static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) |
| { |
| struct spi_transfer *xfer; |
| void *tmp; |
| unsigned int max_tx, max_rx; |
| |
| if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) |
| && !(msg->spi->mode & SPI_3WIRE)) { |
| max_tx = 0; |
| max_rx = 0; |
| |
| list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) && |
| !xfer->tx_buf) |
| max_tx = max(xfer->len, max_tx); |
| if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) && |
| !xfer->rx_buf) |
| max_rx = max(xfer->len, max_rx); |
| } |
| |
| if (max_tx) { |
| tmp = krealloc(ctlr->dummy_tx, max_tx, |
| GFP_KERNEL | GFP_DMA); |
| if (!tmp) |
| return -ENOMEM; |
| ctlr->dummy_tx = tmp; |
| memset(tmp, 0, max_tx); |
| } |
| |
| if (max_rx) { |
| tmp = krealloc(ctlr->dummy_rx, max_rx, |
| GFP_KERNEL | GFP_DMA); |
| if (!tmp) |
| return -ENOMEM; |
| ctlr->dummy_rx = tmp; |
| } |
| |
| if (max_tx || max_rx) { |
| list_for_each_entry(xfer, &msg->transfers, |
| transfer_list) { |
| if (!xfer->len) |
| continue; |
| if (!xfer->tx_buf) |
| xfer->tx_buf = ctlr->dummy_tx; |
| if (!xfer->rx_buf) |
| xfer->rx_buf = ctlr->dummy_rx; |
| } |
| } |
| } |
| |
| return __spi_map_msg(ctlr, msg); |
| } |
| |
| static int spi_transfer_wait(struct spi_controller *ctlr, |
| struct spi_message *msg, |
| struct spi_transfer *xfer) |
| { |
| struct spi_statistics *statm = &ctlr->statistics; |
| struct spi_statistics *stats = &msg->spi->statistics; |
| u32 speed_hz = xfer->speed_hz; |
| unsigned long long ms; |
| |
| if (spi_controller_is_slave(ctlr)) { |
| if (wait_for_completion_interruptible(&ctlr->xfer_completion)) { |
| dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n"); |
| return -EINTR; |
| } |
| } else { |
| if (!speed_hz) |
| speed_hz = 100000; |
| |
| ms = 8LL * 1000LL * xfer->len; |
| do_div(ms, speed_hz); |
| ms += ms + 200; /* some tolerance */ |
| |
| if (ms > UINT_MAX) |
| ms = UINT_MAX; |
| |
| ms = wait_for_completion_timeout(&ctlr->xfer_completion, |
| msecs_to_jiffies(ms)); |
| |
| if (ms == 0) { |
| SPI_STATISTICS_INCREMENT_FIELD(statm, timedout); |
| SPI_STATISTICS_INCREMENT_FIELD(stats, timedout); |
| dev_err(&msg->spi->dev, |
| "SPI transfer timed out\n"); |
| return -ETIMEDOUT; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static void _spi_transfer_delay_ns(u32 ns) |
| { |
| if (!ns) |
| return; |
| if (ns <= 1000) { |
| ndelay(ns); |
| } else { |
| u32 us = DIV_ROUND_UP(ns, 1000); |
| |
| if (us <= 10) |
| udelay(us); |
| else |
| usleep_range(us, us + DIV_ROUND_UP(us, 10)); |
| } |
| } |
| |
| int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer) |
| { |
| u32 delay = _delay->value; |
| u32 unit = _delay->unit; |
| u32 hz; |
| |
| if (!delay) |
| return 0; |
| |
| switch (unit) { |
| case SPI_DELAY_UNIT_USECS: |
| delay *= 1000; |
| break; |
| case SPI_DELAY_UNIT_NSECS: /* nothing to do here */ |
| break; |
| case SPI_DELAY_UNIT_SCK: |
| /* clock cycles need to be obtained from spi_transfer */ |
| if (!xfer) |
| return -EINVAL; |
| /* if there is no effective speed know, then approximate |
| * by underestimating with half the requested hz |
| */ |
| hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2; |
| if (!hz) |
| return -EINVAL; |
| delay *= DIV_ROUND_UP(1000000000, hz); |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| return delay; |
| } |
| EXPORT_SYMBOL_GPL(spi_delay_to_ns); |
| |
| int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer) |
| { |
| int delay; |
| |
| might_sleep(); |
| |
| if (!_delay) |
| return -EINVAL; |
| |
| delay = spi_delay_to_ns(_delay, xfer); |
| if (delay < 0) |
| return delay; |
| |
| _spi_transfer_delay_ns(delay); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(spi_delay_exec); |
| |
| static void _spi_transfer_cs_change_delay(struct spi_message *msg, |
| struct spi_transfer *xfer) |
| { |
| u32 delay = xfer->cs_change_delay.value; |
| u32 unit = xfer->cs_change_delay.unit; |
| int ret; |
| |
| /* return early on "fast" mode - for everything but USECS */ |
| if (!delay) { |
| if (unit == SPI_DELAY_UNIT_USECS) |
| _spi_transfer_delay_ns(10000); |
| return; |
| } |
| |
| ret = spi_delay_exec(&xfer->cs_change_delay, xfer); |
| if (ret) { |
| dev_err_once(&msg->spi->dev, |
| "Use of unsupported delay unit %i, using default of 10us\n", |
| unit); |
| _spi_transfer_delay_ns(10000); |
| } |
| } |
| |
| /* |
| * spi_transfer_one_message - Default implementation of transfer_one_message() |
| * |
| * This is a standard implementation of transfer_one_message() for |
| * drivers which implement a transfer_one() operation. It provides |
| * standard handling of delays and chip select management. |
| */ |
| static int spi_transfer_one_message(struct spi_controller *ctlr, |
| struct spi_message *msg) |
| { |
| struct spi_transfer *xfer; |
| bool keep_cs = false; |
| int ret = 0; |
| struct spi_statistics *statm = &ctlr->statistics; |
| struct spi_statistics *stats = &msg->spi->statistics; |
| |
| spi_set_cs(msg->spi, true, false); |
| |
| SPI_STATISTICS_INCREMENT_FIELD(statm, messages); |
| SPI_STATISTICS_INCREMENT_FIELD(stats, messages); |
| |
| list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| trace_spi_transfer_start(msg, xfer); |
| |
| spi_statistics_add_transfer_stats(statm, xfer, ctlr); |
| spi_statistics_add_transfer_stats(stats, xfer, ctlr); |
| |
| if (!ctlr->ptp_sts_supported) { |
| xfer->ptp_sts_word_pre = 0; |
| ptp_read_system_prets(xfer->ptp_sts); |
| } |
| |
| if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) { |
| reinit_completion(&ctlr->xfer_completion); |
| |
| fallback_pio: |
| ret = ctlr->transfer_one(ctlr, msg->spi, xfer); |
| if (ret < 0) { |
| if (ctlr->cur_msg_mapped && |
| (xfer->error & SPI_TRANS_FAIL_NO_START)) { |
| __spi_unmap_msg(ctlr, msg); |
| ctlr->fallback = true; |
| xfer->error &= ~SPI_TRANS_FAIL_NO_START; |
| goto fallback_pio; |
| } |
| |
| SPI_STATISTICS_INCREMENT_FIELD(statm, |
| errors); |
| SPI_STATISTICS_INCREMENT_FIELD(stats, |
| errors); |
| dev_err(&msg->spi->dev, |
| "SPI transfer failed: %d\n", ret); |
| goto out; |
| } |
| |
| if (ret > 0) { |
| ret = spi_transfer_wait(ctlr, msg, xfer); |
| if (ret < 0) |
| msg->status = ret; |
| } |
| } else { |
| if (xfer->len) |
| dev_err(&msg->spi->dev, |
| "Bufferless transfer has length %u\n", |
| xfer->len); |
| } |
| |
| if (!ctlr->ptp_sts_supported) { |
| ptp_read_system_postts(xfer->ptp_sts); |
| xfer->ptp_sts_word_post = xfer->len; |
| } |
| |
| trace_spi_transfer_stop(msg, xfer); |
| |
| if (msg->status != -EINPROGRESS) |
| goto out; |
| |
| spi_transfer_delay_exec(xfer); |
| |
| if (xfer->cs_change) { |
| if (list_is_last(&xfer->transfer_list, |
| &msg->transfers)) { |
| keep_cs = true; |
| } else { |
| spi_set_cs(msg->spi, false, false); |
| _spi_transfer_cs_change_delay(msg, xfer); |
| spi_set_cs(msg->spi, true, false); |
| } |
| } |
| |
| msg->actual_length += xfer->len; |
| } |
| |
| out: |
| if (ret != 0 || !keep_cs) |
| spi_set_cs(msg->spi, false, false); |
| |
| if (msg->status == -EINPROGRESS) |
| msg->status = ret; |
| |
| if (msg->status && ctlr->handle_err) |
| ctlr->handle_err(ctlr, msg); |
| |
| spi_finalize_current_message(ctlr); |
| |
| return ret; |
| } |
| |
| /** |
| * spi_finalize_current_transfer - report completion of a transfer |
| * @ctlr: the controller reporting completion |
| * |
| * Called by SPI drivers using the core transfer_one_message() |
| * implementation to notify it that the current interrupt driven |
| * transfer has finished and the next one may be scheduled. |
| */ |
| void spi_finalize_current_transfer(struct spi_controller *ctlr) |
| { |
| complete(&ctlr->xfer_completion); |
| } |
| EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); |
| |
| static void spi_idle_runtime_pm(struct spi_controller *ctlr) |
| { |
| if (ctlr->auto_runtime_pm) { |
| pm_runtime_mark_last_busy(ctlr->dev.parent); |
| pm_runtime_put_autosuspend(ctlr->dev.parent); |
| } |
| } |
| |
| /** |
| * __spi_pump_messages - function which processes spi message queue |
| * @ctlr: controller to process queue for |
| * @in_kthread: true if we are in the context of the message pump thread |
| * |
| * This function checks if there is any spi message in the queue that |
| * needs processing and if so call out to the driver to initialize hardware |
| * and transfer each message. |
| * |
| * Note that it is called both from the kthread itself and also from |
| * inside spi_sync(); the queue extraction handling at the top of the |
| * function should deal with this safely. |
| */ |
| static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) |
| { |
| struct spi_transfer *xfer; |
| struct spi_message *msg; |
| bool was_busy = false; |
| unsigned long flags; |
| int ret; |
| |
| /* Lock queue */ |
| spin_lock_irqsave(&ctlr->queue_lock, flags); |
| |
| /* Make sure we are not already running a message */ |
| if (ctlr->cur_msg) { |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| return; |
| } |
| |
| /* If another context is idling the device then defer */ |
| if (ctlr->idling) { |
| kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| return; |
| } |
| |
| /* Check if the queue is idle */ |
| if (list_empty(&ctlr->queue) || !ctlr->running) { |
| if (!ctlr->busy) { |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| return; |
| } |
| |
| /* Defer any non-atomic teardown to the thread */ |
| if (!in_kthread) { |
| if (!ctlr->dummy_rx && !ctlr->dummy_tx && |
| !ctlr->unprepare_transfer_hardware) { |
| spi_idle_runtime_pm(ctlr); |
| ctlr->busy = false; |
| trace_spi_controller_idle(ctlr); |
| } else { |
| kthread_queue_work(ctlr->kworker, |
| &ctlr->pump_messages); |
| } |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| return; |
| } |
| |
| ctlr->busy = false; |
| ctlr->idling = true; |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| |
| kfree(ctlr->dummy_rx); |
| ctlr->dummy_rx = NULL; |
| kfree(ctlr->dummy_tx); |
| ctlr->dummy_tx = NULL; |
| if (ctlr->unprepare_transfer_hardware && |
| ctlr->unprepare_transfer_hardware(ctlr)) |
| dev_err(&ctlr->dev, |
| "failed to unprepare transfer hardware\n"); |
| spi_idle_runtime_pm(ctlr); |
| trace_spi_controller_idle(ctlr); |
| |
| spin_lock_irqsave(&ctlr->queue_lock, flags); |
| ctlr->idling = false; |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| return; |
| } |
| |
| /* Extract head of queue */ |
| msg = list_first_entry(&ctlr->queue, struct spi_message, queue); |
| ctlr->cur_msg = msg; |
| |
| list_del_init(&msg->queue); |
| if (ctlr->busy) |
| was_busy = true; |
| else |
| ctlr->busy = true; |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| |
| mutex_lock(&ctlr->io_mutex); |
| |
| if (!was_busy && ctlr->auto_runtime_pm) { |
| ret = pm_runtime_get_sync(ctlr->dev.parent); |
| if (ret < 0) { |
| pm_runtime_put_noidle(ctlr->dev.parent); |
| dev_err(&ctlr->dev, "Failed to power device: %d\n", |
| ret); |
| mutex_unlock(&ctlr->io_mutex); |
| return; |
| } |
| } |
| |
| if (!was_busy) |
| trace_spi_controller_busy(ctlr); |
| |
| if (!was_busy && ctlr->prepare_transfer_hardware) { |
| ret = ctlr->prepare_transfer_hardware(ctlr); |
| if (ret) { |
| dev_err(&ctlr->dev, |
| "failed to prepare transfer hardware: %d\n", |
| ret); |
| |
| if (ctlr->auto_runtime_pm) |
| pm_runtime_put(ctlr->dev.parent); |
| |
| msg->status = ret; |
| spi_finalize_current_message(ctlr); |
| |
| mutex_unlock(&ctlr->io_mutex); |
| return; |
| } |
| } |
| |
| trace_spi_message_start(msg); |
| |
| if (ctlr->prepare_message) { |
| ret = ctlr->prepare_message(ctlr, msg); |
| if (ret) { |
| dev_err(&ctlr->dev, "failed to prepare message: %d\n", |
| ret); |
| msg->status = ret; |
| spi_finalize_current_message(ctlr); |
| goto out; |
| } |
| ctlr->cur_msg_prepared = true; |
| } |
| |
| ret = spi_map_msg(ctlr, msg); |
| if (ret) { |
| msg->status = ret; |
| spi_finalize_current_message(ctlr); |
| goto out; |
| } |
| |
| if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { |
| list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| xfer->ptp_sts_word_pre = 0; |
| ptp_read_system_prets(xfer->ptp_sts); |
| } |
| } |
| |
| ret = ctlr->transfer_one_message(ctlr, msg); |
| if (ret) { |
| dev_err(&ctlr->dev, |
| "failed to transfer one message from queue\n"); |
| goto out; |
| } |
| |
| out: |
| mutex_unlock(&ctlr->io_mutex); |
| |
| /* Prod the scheduler in case transfer_one() was busy waiting */ |
| if (!ret) |
| cond_resched(); |
| } |
| |
| /** |
| * spi_pump_messages - kthread work function which processes spi message queue |
| * @work: pointer to kthread work struct contained in the controller struct |
| */ |
| static void spi_pump_messages(struct kthread_work *work) |
| { |
| struct spi_controller *ctlr = |
| container_of(work, struct spi_controller, pump_messages); |
| |
| __spi_pump_messages(ctlr, true); |
| } |
| |
| /** |
| * spi_take_timestamp_pre - helper for drivers to collect the beginning of the |
| * TX timestamp for the requested byte from the SPI |
| * transfer. The frequency with which this function |
| * must be called (once per word, once for the whole |
| * transfer, once per batch of words etc) is arbitrary |
| * as long as the @tx buffer offset is greater than or |
| * equal to the requested byte at the time of the |
| * call. The timestamp is only taken once, at the |
| * first such call. It is assumed that the driver |
| * advances its @tx buffer pointer monotonically. |
| * @ctlr: Pointer to the spi_controller structure of the driver |
| * @xfer: Pointer to the transfer being timestamped |
| * @progress: How many words (not bytes) have been transferred so far |
| * @irqs_off: If true, will disable IRQs and preemption for the duration of the |
| * transfer, for less jitter in time measurement. Only compatible |
| * with PIO drivers. If true, must follow up with |
| * spi_take_timestamp_post or otherwise system will crash. |
| * WARNING: for fully predictable results, the CPU frequency must |
| * also be under control (governor). |
| */ |
| void spi_take_timestamp_pre(struct spi_controller *ctlr, |
| struct spi_transfer *xfer, |
| size_t progress, bool irqs_off) |
| { |
| if (!xfer->ptp_sts) |
| return; |
| |
| if (xfer->timestamped) |
| return; |
| |
| if (progress > xfer->ptp_sts_word_pre) |
| return; |
| |
| /* Capture the resolution of the timestamp */ |
| xfer->ptp_sts_word_pre = progress; |
| |
| if (irqs_off) { |
| local_irq_save(ctlr->irq_flags); |
| preempt_disable(); |
| } |
| |
| ptp_read_system_prets(xfer->ptp_sts); |
| } |
| EXPORT_SYMBOL_GPL(spi_take_timestamp_pre); |
| |
| /** |
| * spi_take_timestamp_post - helper for drivers to collect the end of the |
| * TX timestamp for the requested byte from the SPI |
| * transfer. Can be called with an arbitrary |
| * frequency: only the first call where @tx exceeds |
| * or is equal to the requested word will be |
| * timestamped. |
| * @ctlr: Pointer to the spi_controller structure of the driver |
| * @xfer: Pointer to the transfer being timestamped |
| * @progress: How many words (not bytes) have been transferred so far |
| * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU. |
| */ |
| void spi_take_timestamp_post(struct spi_controller *ctlr, |
| struct spi_transfer *xfer, |
| size_t progress, bool irqs_off) |
| { |
| if (!xfer->ptp_sts) |
| return; |
| |
| if (xfer->timestamped) |
| return; |
| |
| if (progress < xfer->ptp_sts_word_post) |
| return; |
| |
| ptp_read_system_postts(xfer->ptp_sts); |
| |
| if (irqs_off) { |
| local_irq_restore(ctlr->irq_flags); |
| preempt_enable(); |
| } |
| |
| /* Capture the resolution of the timestamp */ |
| xfer->ptp_sts_word_post = progress; |
| |
| xfer->timestamped = true; |
| } |
| EXPORT_SYMBOL_GPL(spi_take_timestamp_post); |
| |
| /** |
| * spi_set_thread_rt - set the controller to pump at realtime priority |
| * @ctlr: controller to boost priority of |
| * |
| * This can be called because the controller requested realtime priority |
| * (by setting the ->rt value before calling spi_register_controller()) or |
| * because a device on the bus said that its transfers needed realtime |
| * priority. |
| * |
| * NOTE: at the moment if any device on a bus says it needs realtime then |
| * the thread will be at realtime priority for all transfers on that |
| * controller. If this eventually becomes a problem we may see if we can |
| * find a way to boost the priority only temporarily during relevant |
| * transfers. |
| */ |
| static void spi_set_thread_rt(struct spi_controller *ctlr) |
| { |
| dev_info(&ctlr->dev, |
| "will run message pump with realtime priority\n"); |
| sched_set_fifo(ctlr->kworker->task); |
| } |
| |
| static int spi_init_queue(struct spi_controller *ctlr) |
| { |
| ctlr->running = false; |
| ctlr->busy = false; |
| |
| ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev)); |
| if (IS_ERR(ctlr->kworker)) { |
| dev_err(&ctlr->dev, "failed to create message pump kworker\n"); |
| return PTR_ERR(ctlr->kworker); |
| } |
| |
| kthread_init_work(&ctlr->pump_messages, spi_pump_messages); |
| |
| /* |
| * Controller config will indicate if this controller should run the |
| * message pump with high (realtime) priority to reduce the transfer |
| * latency on the bus by minimising the delay between a transfer |
| * request and the scheduling of the message pump thread. Without this |
| * setting the message pump thread will remain at default priority. |
| */ |
| if (ctlr->rt) |
| spi_set_thread_rt(ctlr); |
| |
| return 0; |
| } |
| |
| /** |
| * spi_get_next_queued_message() - called by driver to check for queued |
| * messages |
| * @ctlr: the controller to check for queued messages |
| * |
| * If there are more messages in the queue, the next message is returned from |
| * this call. |
| * |
| * Return: the next message in the queue, else NULL if the queue is empty. |
| */ |
| struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr) |
| { |
| struct spi_message *next; |
| unsigned long flags; |
| |
| /* get a pointer to the next message, if any */ |
| spin_lock_irqsave(&ctlr->queue_lock, flags); |
| next = list_first_entry_or_null(&ctlr->queue, struct spi_message, |
| queue); |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| |
| return next; |
| } |
| EXPORT_SYMBOL_GPL(spi_get_next_queued_message); |
| |
| /** |
| * spi_finalize_current_message() - the current message is complete |
| * @ctlr: the controller to return the message to |
| * |
| * Called by the driver to notify the core that the message in the front of the |
| * queue is complete and can be removed from the queue. |
| */ |
| void spi_finalize_current_message(struct spi_controller *ctlr) |
| { |
| struct spi_transfer *xfer; |
| struct spi_message *mesg; |
| unsigned long flags; |
| int ret; |
| |
| spin_lock_irqsave(&ctlr->queue_lock, flags); |
| mesg = ctlr->cur_msg; |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| |
| if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { |
| list_for_each_entry(xfer, &mesg->transfers, transfer_list) { |
| ptp_read_system_postts(xfer->ptp_sts); |
| xfer->ptp_sts_word_post = xfer->len; |
| } |
| } |
| |
| if (unlikely(ctlr->ptp_sts_supported)) |
| list_for_each_entry(xfer, &mesg->transfers, transfer_list) |
| WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped); |
| |
| spi_unmap_msg(ctlr, mesg); |
| |
| /* In the prepare_messages callback the spi bus has the opportunity to |
| * split a transfer to smaller chunks. |
| * Release splited transfers here since spi_map_msg is done on the |
| * splited transfers. |
| */ |
| spi_res_release(ctlr, mesg); |
| |
| if (ctlr->cur_msg_prepared && ctlr->unprepare_message) { |
| ret = ctlr->unprepare_message(ctlr, mesg); |
| if (ret) { |
| dev_err(&ctlr->dev, "failed to unprepare message: %d\n", |
| ret); |
| } |
| } |
| |
| spin_lock_irqsave(&ctlr->queue_lock, flags); |
| ctlr->cur_msg = NULL; |
| ctlr->cur_msg_prepared = false; |
| ctlr->fallback = false; |
| kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| |
| trace_spi_message_done(mesg); |
| |
| mesg->state = NULL; |
| if (mesg->complete) |
| mesg->complete(mesg->context); |
| } |
| EXPORT_SYMBOL_GPL(spi_finalize_current_message); |
| |
| static int spi_start_queue(struct spi_controller *ctlr) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&ctlr->queue_lock, flags); |
| |
| if (ctlr->running || ctlr->busy) { |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| return -EBUSY; |
| } |
| |
| ctlr->running = true; |
| ctlr->cur_msg = NULL; |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| |
| kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); |
| |
| return 0; |
| } |
| |
| static int spi_stop_queue(struct spi_controller *ctlr) |
| { |
| unsigned long flags; |
| unsigned limit = 500; |
| int ret = 0; |
| |
| spin_lock_irqsave(&ctlr->queue_lock, flags); |
| |
| /* |
| * This is a bit lame, but is optimized for the common execution path. |
| * A wait_queue on the ctlr->busy could be used, but then the common |
| * execution path (pump_messages) would be required to call wake_up or |
| * friends on every SPI message. Do this instead. |
| */ |
| while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) { |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| usleep_range(10000, 11000); |
| spin_lock_irqsave(&ctlr->queue_lock, flags); |
| } |
| |
| if (!list_empty(&ctlr->queue) || ctlr->busy) |
| ret = -EBUSY; |
| else |
| ctlr->running = false; |
| |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| |
| if (ret) { |
| dev_warn(&ctlr->dev, "could not stop message queue\n"); |
| return ret; |
| } |
| return ret; |
| } |
| |
| static int spi_destroy_queue(struct spi_controller *ctlr) |
| { |
| int ret; |
| |
| ret = spi_stop_queue(ctlr); |
| |
| /* |
| * kthread_flush_worker will block until all work is done. |
| * If the reason that stop_queue timed out is that the work will never |
| * finish, then it does no good to call flush/stop thread, so |
| * return anyway. |
| */ |
| if (ret) { |
| dev_err(&ctlr->dev, "problem destroying queue\n"); |
| return ret; |
| } |
| |
| kthread_destroy_worker(ctlr->kworker); |
| |
| return 0; |
| } |
| |
| static int __spi_queued_transfer(struct spi_device *spi, |
| struct spi_message *msg, |
| bool need_pump) |
| { |
| struct spi_controller *ctlr = spi->controller; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&ctlr->queue_lock, flags); |
| |
| if (!ctlr->running) { |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| return -ESHUTDOWN; |
| } |
| msg->actual_length = 0; |
| msg->status = -EINPROGRESS; |
| |
| list_add_tail(&msg->queue, &ctlr->queue); |
| if (!ctlr->busy && need_pump) |
| kthread_queue_work(ctlr->kworker, &ctlr->pump_messages); |
| |
| spin_unlock_irqrestore(&ctlr->queue_lock, flags); |
| return 0; |
| } |
| |
| /** |
| * spi_queued_transfer - transfer function for queued transfers |
| * @spi: spi device which is requesting transfer |
| * @msg: spi message which is to handled is queued to driver queue |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) |
| { |
| return __spi_queued_transfer(spi, msg, true); |
| } |
| |
| static int spi_controller_initialize_queue(struct spi_controller *ctlr) |
| { |
| int ret; |
| |
| ctlr->transfer = spi_queued_transfer; |
| if (!ctlr->transfer_one_message) |
| ctlr->transfer_one_message = spi_transfer_one_message; |
| |
| /* Initialize and start queue */ |
| ret = spi_init_queue(ctlr); |
| if (ret) { |
| dev_err(&ctlr->dev, "problem initializing queue\n"); |
| goto err_init_queue; |
| } |
| ctlr->queued = true; |
| ret = spi_start_queue(ctlr); |
| if (ret) { |
| dev_err(&ctlr->dev, "problem starting queue\n"); |
| goto err_start_queue; |
| } |
| |
| return 0; |
| |
| err_start_queue: |
| spi_destroy_queue(ctlr); |
| err_init_queue: |
| return ret; |
| } |
| |
| /** |
| * spi_flush_queue - Send all pending messages in the queue from the callers' |
| * context |
| * @ctlr: controller to process queue for |
| * |
| * This should be used when one wants to ensure all pending messages have been |
| * sent before doing something. Is used by the spi-mem code to make sure SPI |
| * memory operations do not preempt regular SPI transfers that have been queued |
| * before the spi-mem operation. |
| */ |
| void spi_flush_queue(struct spi_controller *ctlr) |
| { |
| if (ctlr->transfer == spi_queued_transfer) |
| __spi_pump_messages(ctlr, false); |
| } |
| |
| /*-------------------------------------------------------------------------*/ |
| |
| #if defined(CONFIG_OF) |
| static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi, |
| struct device_node *nc) |
| { |
| u32 value; |
| int rc; |
| |
| /* Mode (clock phase/polarity/etc.) */ |
| if (of_property_read_bool(nc, "spi-cpha")) |
| spi->mode |= SPI_CPHA; |
| if (of_property_read_bool(nc, "spi-cpol")) |
| spi->mode |= SPI_CPOL; |
| if (of_property_read_bool(nc, "spi-3wire")) |
| spi->mode |= SPI_3WIRE; |
| if (of_property_read_bool(nc, "spi-lsb-first")) |
| spi->mode |= SPI_LSB_FIRST; |
| if (of_property_read_bool(nc, "spi-cs-high")) |
| spi->mode |= SPI_CS_HIGH; |
| |
| /* Device DUAL/QUAD mode */ |
| if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { |
| switch (value) { |
| case 0: |
| spi->mode |= SPI_NO_TX; |
| break; |
| case 1: |
| break; |
| case 2: |
| spi->mode |= SPI_TX_DUAL; |
| break; |
| case 4: |
| spi->mode |= SPI_TX_QUAD; |
| break; |
| case 8: |
| spi->mode |= SPI_TX_OCTAL; |
| break; |
| default: |
| dev_warn(&ctlr->dev, |
| "spi-tx-bus-width %d not supported\n", |
| value); |
| break; |
| } |
| } |
| |
| if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { |
| switch (value) { |
| case 0: |
| spi->mode |= SPI_NO_RX; |
| break; |
| case 1: |
| break; |
| case 2: |
| spi->mode |= SPI_RX_DUAL; |
| break; |
| case 4: |
| spi->mode |= SPI_RX_QUAD; |
| break; |
| case 8: |
| spi->mode |= SPI_RX_OCTAL; |
| break; |
| default: |
| dev_warn(&ctlr->dev, |
| "spi-rx-bus-width %d not supported\n", |
| value); |
| break; |
| } |
| } |
| |
| if (spi_controller_is_slave(ctlr)) { |
| if (!of_node_name_eq(nc, "slave")) { |
| dev_err(&ctlr->dev, "%pOF is not called 'slave'\n", |
| nc); |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| /* Device address */ |
| rc = of_property_read_u32(nc, "reg", &value); |
| if (rc) { |
| dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n", |
| nc, rc); |
| return rc; |
| } |
| spi->chip_select = value; |
| |
| /* Device speed */ |
| if (!of_property_read_u32(nc, "spi-max-frequency", &value)) |
| spi->max_speed_hz = value; |
| |
| return 0; |
| } |
| |
| static struct spi_device * |
| of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc) |
| { |
| struct spi_device *spi; |
| int rc; |
| |
| /* Alloc an spi_device */ |
| spi = spi_alloc_device(ctlr); |
| if (!spi) { |
| dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc); |
| rc = -ENOMEM; |
| goto err_out; |
| } |
| |
| /* Select device driver */ |
| rc = of_modalias_node(nc, spi->modalias, |
| sizeof(spi->modalias)); |
| if (rc < 0) { |
| dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc); |
| goto err_out; |
| } |
| |
| rc = of_spi_parse_dt(ctlr, spi, nc); |
| if (rc) |
| goto err_out; |
| |
| /* Store a pointer to the node in the device structure */ |
| of_node_get(nc); |
| spi->dev.of_node = nc; |
| |
| /* Register the new device */ |
| rc = spi_add_device(spi); |
| if (rc) { |
| dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc); |
| goto err_of_node_put; |
| } |
| |
| return spi; |
| |
| err_of_node_put: |
| of_node_put(nc); |
| err_out: |
| spi_dev_put(spi); |
| return ERR_PTR(rc); |
| } |
| |
| /** |
| * of_register_spi_devices() - Register child devices onto the SPI bus |
| * @ctlr: Pointer to spi_controller device |
| * |
| * Registers an spi_device for each child node of controller node which |
| * represents a valid SPI slave. |
| */ |
| static void of_register_spi_devices(struct spi_controller *ctlr) |
| { |
| struct spi_device *spi; |
| struct device_node *nc; |
| |
| if (!ctlr->dev.of_node) |
| return; |
| |
| for_each_available_child_of_node(ctlr->dev.of_node, nc) { |
| if (of_node_test_and_set_flag(nc, OF_POPULATED)) |
| continue; |
| spi = of_register_spi_device(ctlr, nc); |
| if (IS_ERR(spi)) { |
| dev_warn(&ctlr->dev, |
| "Failed to create SPI device for %pOF\n", nc); |
| of_node_clear_flag(nc, OF_POPULATED); |
| } |
| } |
| } |
| #else |
| static void of_register_spi_devices(struct spi_controller *ctlr) { } |
| #endif |
| |
| #ifdef CONFIG_ACPI |
| struct acpi_spi_lookup { |
| struct spi_controller *ctlr; |
| u32 max_speed_hz; |
| u32 mode; |
| int irq; |
| u8 bits_per_word; |
| u8 chip_select; |
| }; |
| |
| static void acpi_spi_parse_apple_properties(struct acpi_device *dev, |
| struct acpi_spi_lookup *lookup) |
| { |
| const union acpi_object *obj; |
| |
| if (!x86_apple_machine) |
| return; |
| |
| if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj) |
| && obj->buffer.length >= 4) |
| lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer; |
| |
| if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj) |
| && obj->buffer.length == 8) |
| lookup->bits_per_word = *(u64 *)obj->buffer.pointer; |
| |
| if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj) |
| && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer) |
| lookup->mode |= SPI_LSB_FIRST; |
| |
| if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj) |
| && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) |
| lookup->mode |= SPI_CPOL; |
| |
| if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj) |
| && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer) |
| lookup->mode |= SPI_CPHA; |
| } |
| |
| static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) |
| { |
| struct acpi_spi_lookup *lookup = data; |
| struct spi_controller *ctlr = lookup->ctlr; |
| |
| if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { |
| struct acpi_resource_spi_serialbus *sb; |
| acpi_handle parent_handle; |
| acpi_status status; |
| |
| sb = &ares->data.spi_serial_bus; |
| if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { |
| |
| status = acpi_get_handle(NULL, |
| sb->resource_source.string_ptr, |
| &parent_handle); |
| |
| if (ACPI_FAILURE(status) || |
| ACPI_HANDLE(ctlr->dev.parent) != parent_handle) |
| return -ENODEV; |
| |
| /* |
| * ACPI DeviceSelection numbering is handled by the |
| * host controller driver in Windows and can vary |
| * from driver to driver. In Linux we always expect |
| * 0 .. max - 1 so we need to ask the driver to |
| * translate between the two schemes. |
| */ |
| if (ctlr->fw_translate_cs) { |
| int cs = ctlr->fw_translate_cs(ctlr, |
| sb->device_selection); |
| if (cs < 0) |
| return cs; |
| lookup->chip_select = cs; |
| } else { |
| lookup->chip_select = sb->device_selection; |
| } |
| |
| lookup->max_speed_hz = sb->connection_speed; |
| lookup->bits_per_word = sb->data_bit_length; |
| |
| if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) |
| lookup->mode |= SPI_CPHA; |
| if (sb->clock_polarity == ACPI_SPI_START_HIGH) |
| lookup->mode |= SPI_CPOL; |
| if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) |
| lookup->mode |= SPI_CS_HIGH; |
| } |
| } else if (lookup->irq < 0) { |
| struct resource r; |
| |
| if (acpi_dev_resource_interrupt(ares, 0, &r)) |
| lookup->irq = r.start; |
| } |
| |
| /* Always tell the ACPI core to skip this resource */ |
| return 1; |
| } |
| |
| static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, |
| struct acpi_device *adev) |
| { |
| acpi_handle parent_handle = NULL; |
| struct list_head resource_list; |
| struct acpi_spi_lookup lookup = {}; |
| struct spi_device *spi; |
| int ret; |
| |
| if (acpi_bus_get_status(adev) || !adev->status.present || |
| acpi_device_enumerated(adev)) |
| return AE_OK; |
| |
| lookup.ctlr = ctlr; |
| lookup.irq = -1; |
| |
| INIT_LIST_HEAD(&resource_list); |
| ret = acpi_dev_get_resources(adev, &resource_list, |
| acpi_spi_add_resource, &lookup); |
| acpi_dev_free_resource_list(&resource_list); |
| |
| if (ret < 0) |
| /* found SPI in _CRS but it points to another controller */ |
| return AE_OK; |
| |
| if (!lookup.max_speed_hz && |
| ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) && |
| ACPI_HANDLE(ctlr->dev.parent) == parent_handle) { |
| /* Apple does not use _CRS but nested devices for SPI slaves */ |
| acpi_spi_parse_apple_properties(adev, &lookup); |
| } |
| |
| if (!lookup.max_speed_hz) |
| return AE_OK; |
| |
| spi = spi_alloc_device(ctlr); |
| if (!spi) { |
| dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n", |
| dev_name(&adev->dev)); |
| return AE_NO_MEMORY; |
| } |
| |
| |
| ACPI_COMPANION_SET(&spi->dev, adev); |
| spi->max_speed_hz = lookup.max_speed_hz; |
| spi->mode |= lookup.mode; |
| spi->irq = lookup.irq; |
| spi->bits_per_word = lookup.bits_per_word; |
| spi->chip_select = lookup.chip_select; |
| |
| acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias, |
| sizeof(spi->modalias)); |
| |
| if (spi->irq < 0) |
| spi->irq = acpi_dev_gpio_irq_get(adev, 0); |
| |
| acpi_device_set_enumerated(adev); |
| |
| adev->power.flags.ignore_parent = true; |
| if (spi_add_device(spi)) { |
| adev->power.flags.ignore_parent = false; |
| dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n", |
| dev_name(&adev->dev)); |
| spi_dev_put(spi); |
| } |
| |
| return AE_OK; |
| } |
| |
| static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, |
| void *data, void **return_value) |
| { |
| struct spi_controller *ctlr = data; |
| struct acpi_device *adev; |
| |
| if (acpi_bus_get_device(handle, &adev)) |
| return AE_OK; |
| |
| return acpi_register_spi_device(ctlr, adev); |
| } |
| |
| #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32 |
| |
| static void acpi_register_spi_devices(struct spi_controller *ctlr) |
| { |
| acpi_status status; |
| acpi_handle handle; |
| |
| handle = ACPI_HANDLE(ctlr->dev.parent); |
| if (!handle) |
| return; |
| |
| status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, |
| SPI_ACPI_ENUMERATE_MAX_DEPTH, |
| acpi_spi_add_device, NULL, ctlr, NULL); |
| if (ACPI_FAILURE(status)) |
| dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n"); |
| } |
| #else |
| static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {} |
| #endif /* CONFIG_ACPI */ |
| |
| static void spi_controller_release(struct device *dev) |
| { |
| struct spi_controller *ctlr; |
| |
| ctlr = container_of(dev, struct spi_controller, dev); |
| kfree(ctlr); |
| } |
| |
| static struct class spi_master_class = { |
| .name = "spi_master", |
| .owner = THIS_MODULE, |
| .dev_release = spi_controller_release, |
| .dev_groups = spi_master_groups, |
| }; |
| |
| #ifdef CONFIG_SPI_SLAVE |
| /** |
| * spi_slave_abort - abort the ongoing transfer request on an SPI slave |
| * controller |
| * @spi: device used for the current transfer |
| */ |
| int spi_slave_abort(struct spi_device *spi) |
| { |
| struct spi_controller *ctlr = spi->controller; |
| |
| if (spi_controller_is_slave(ctlr) && ctlr->slave_abort) |
| return ctlr->slave_abort(ctlr); |
| |
| return -ENOTSUPP; |
| } |
| EXPORT_SYMBOL_GPL(spi_slave_abort); |
| |
| static int match_true(struct device *dev, void *data) |
| { |
| return 1; |
| } |
| |
| static ssize_t slave_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct spi_controller *ctlr = container_of(dev, struct spi_controller, |
| dev); |
| struct device *child; |
| |
| child = device_find_child(&ctlr->dev, NULL, match_true); |
| return sprintf(buf, "%s\n", |
| child ? to_spi_device(child)->modalias : NULL); |
| } |
| |
| static ssize_t slave_store(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct spi_controller *ctlr = container_of(dev, struct spi_controller, |
| dev); |
| struct spi_device *spi; |
| struct device *child; |
| char name[32]; |
| int rc; |
| |
| rc = sscanf(buf, "%31s", name); |
| if (rc != 1 || !name[0]) |
| return -EINVAL; |
| |
| child = device_find_child(&ctlr->dev, NULL, match_true); |
| if (child) { |
| /* Remove registered slave */ |
| device_unregister(child); |
| put_device(child); |
| } |
| |
| if (strcmp(name, "(null)")) { |
| /* Register new slave */ |
| spi = spi_alloc_device(ctlr); |
| if (!spi) |
| return -ENOMEM; |
| |
| strlcpy(spi->modalias, name, sizeof(spi->modalias)); |
| |
| rc = spi_add_device(spi); |
| if (rc) { |
| spi_dev_put(spi); |
| return rc; |
| } |
| } |
| |
| return count; |
| } |
| |
| static DEVICE_ATTR_RW(slave); |
| |
| static struct attribute *spi_slave_attrs[] = { |
| &dev_attr_slave.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group spi_slave_group = { |
| .attrs = spi_slave_attrs, |
| }; |
| |
| static const struct attribute_group *spi_slave_groups[] = { |
| &spi_controller_statistics_group, |
| &spi_slave_group, |
| NULL, |
| }; |
| |
| static struct class spi_slave_class = { |
| .name = "spi_slave", |
| .owner = THIS_MODULE, |
| .dev_release = spi_controller_release, |
| .dev_groups = spi_slave_groups, |
| }; |
| #else |
| extern struct class spi_slave_class; /* dummy */ |
| #endif |
| |
| /** |
| * __spi_alloc_controller - allocate an SPI master or slave controller |
| * @dev: the controller, possibly using the platform_bus |
| * @size: how much zeroed driver-private data to allocate; the pointer to this |
| * memory is in the driver_data field of the returned device, accessible |
| * with spi_controller_get_devdata(); the memory is cacheline aligned; |
| * drivers granting DMA access to portions of their private data need to |
| * round up @size using ALIGN(size, dma_get_cache_alignment()). |
| * @slave: flag indicating whether to allocate an SPI master (false) or SPI |
| * slave (true) controller |
| * Context: can sleep |
| * |
| * This call is used only by SPI controller drivers, which are the |
| * only ones directly touching chip registers. It's how they allocate |
| * an spi_controller structure, prior to calling spi_register_controller(). |
| * |
| * This must be called from context that can sleep. |
| * |
| * The caller is responsible for assigning the bus number and initializing the |
| * controller's methods before calling spi_register_controller(); and (after |
| * errors adding the device) calling spi_controller_put() to prevent a memory |
| * leak. |
| * |
| * Return: the SPI controller structure on success, else NULL. |
| */ |
| struct spi_controller *__spi_alloc_controller(struct device *dev, |
| unsigned int size, bool slave) |
| { |
| struct spi_controller *ctlr; |
| size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment()); |
| |
| if (!dev) |
| return NULL; |
| |
| ctlr = kzalloc(size + ctlr_size, GFP_KERNEL); |
| if (!ctlr) |
| return NULL; |
| |
| device_initialize(&ctlr->dev); |
| ctlr->bus_num = -1; |
| ctlr->num_chipselect = 1; |
| ctlr->slave = slave; |
| if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave) |
| ctlr->dev.class = &spi_slave_class; |
| else |
| ctlr->dev.class = &spi_master_class; |
| ctlr->dev.parent = dev; |
| pm_suspend_ignore_children(&ctlr->dev, true); |
| spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size); |
| |
| return ctlr; |
| } |
| EXPORT_SYMBOL_GPL(__spi_alloc_controller); |
| |
| static void devm_spi_release_controller(struct device *dev, void *ctlr) |
| { |
| spi_controller_put(*(struct spi_controller **)ctlr); |
| } |
| |
| /** |
| * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller() |
| * @dev: physical device of SPI controller |
| * @size: how much zeroed driver-private data to allocate |
| * @slave: whether to allocate an SPI master (false) or SPI slave (true) |
| * Context: can sleep |
| * |
| * Allocate an SPI controller and automatically release a reference on it |
| * when @dev is unbound from its driver. Drivers are thus relieved from |
| * having to call spi_controller_put(). |
| * |
| * The arguments to this function are identical to __spi_alloc_controller(). |
| * |
| * Return: the SPI controller structure on success, else NULL. |
| */ |
| struct spi_controller *__devm_spi_alloc_controller(struct device *dev, |
| unsigned int size, |
| bool slave) |
| { |
| struct spi_controller **ptr, *ctlr; |
| |
| ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr), |
| GFP_KERNEL); |
| if (!ptr) |
| return NULL; |
| |
| ctlr = __spi_alloc_controller(dev, size, slave); |
| if (ctlr) { |
| ctlr->devm_allocated = true; |
| *ptr = ctlr; |
| devres_add(dev, ptr); |
| } else { |
| devres_free(ptr); |
| } |
| |
| return ctlr; |
| } |
| EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller); |
| |
| #ifdef CONFIG_OF |
| static int of_spi_get_gpio_numbers(struct spi_controller *ctlr) |
| { |
| int nb, i, *cs; |
| struct device_node *np = ctlr->dev.of_node; |
| |
| if (!np) |
| return 0; |
| |
| nb = of_gpio_named_count(np, "cs-gpios"); |
| ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); |
| |
| /* Return error only for an incorrectly formed cs-gpios property */ |
| if (nb == 0 || nb == -ENOENT) |
| return 0; |
| else if (nb < 0) |
| return nb; |
| |
| cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int), |
| GFP_KERNEL); |
| ctlr->cs_gpios = cs; |
| |
| if (!ctlr->cs_gpios) |
| return -ENOMEM; |
| |
| for (i = 0; i < ctlr->num_chipselect; i++) |
| cs[i] = -ENOENT; |
| |
| for (i = 0; i < nb; i++) |
| cs[i] = of_get_named_gpio(np, "cs-gpios", i); |
| |
| return 0; |
| } |
| #else |
| static int of_spi_get_gpio_numbers(struct spi_controller *ctlr) |
| { |
| return 0; |
| } |
| #endif |
| |
| /** |
| * spi_get_gpio_descs() - grab chip select GPIOs for the master |
| * @ctlr: The SPI master to grab GPIO descriptors for |
| */ |
| static int spi_get_gpio_descs(struct spi_controller *ctlr) |
| { |
| int nb, i; |
| struct gpio_desc **cs; |
| struct device *dev = &ctlr->dev; |
| unsigned long native_cs_mask = 0; |
| unsigned int num_cs_gpios = 0; |
| |
| nb = gpiod_count(dev, "cs"); |
| if (nb < 0) { |
| /* No GPIOs at all is fine, else return the error */ |
| if (nb == -ENOENT) |
| return 0; |
| return nb; |
| } |
| |
| ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); |
| |
| cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs), |
| GFP_KERNEL); |
| if (!cs) |
| return -ENOMEM; |
| ctlr->cs_gpiods = cs; |
| |
| for (i = 0; i < nb; i++) { |
| /* |
| * Most chipselects are active low, the inverted |
| * semantics are handled by special quirks in gpiolib, |
| * so initializing them GPIOD_OUT_LOW here means |
| * "unasserted", in most cases this will drive the physical |
| * line high. |
| */ |
| cs[i] = devm_gpiod_get_index_optional(dev, "cs", i, |
| GPIOD_OUT_LOW); |
| if (IS_ERR(cs[i])) |
| return PTR_ERR(cs[i]); |
| |
| if (cs[i]) { |
| /* |
| * If we find a CS GPIO, name it after the device and |
| * chip select line. |
| */ |
| char *gpioname; |
| |
| gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d", |
| dev_name(dev), i); |
| if (!gpioname) |
| return -ENOMEM; |
| gpiod_set_consumer_name(cs[i], gpioname); |
| num_cs_gpios++; |
| continue; |
| } |
| |
| if (ctlr->max_native_cs && i >= ctlr->max_native_cs) { |
| dev_err(dev, "Invalid native chip select %d\n", i); |
| return -EINVAL; |
| } |
| native_cs_mask |= BIT(i); |
| } |
| |
| ctlr->unused_native_cs = ffz(native_cs_mask); |
| if (num_cs_gpios && ctlr->max_native_cs && |
| ctlr->unused_native_cs >= ctlr->max_native_cs) { |
| dev_err(dev, "No unused native chip select available\n"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int spi_controller_check_ops(struct spi_controller *ctlr) |
| { |
| /* |
| * The controller may implement only the high-level SPI-memory like |
| * operations if it does not support regular SPI transfers, and this is |
| * valid use case. |
| * If ->mem_ops is NULL, we request that at least one of the |
| * ->transfer_xxx() method be implemented. |
| */ |
| if (ctlr->mem_ops) { |
| if (!ctlr->mem_ops->exec_op) |
| return -EINVAL; |
| } else if (!ctlr->transfer && !ctlr->transfer_one && |
| !ctlr->transfer_one_message) { |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * spi_register_controller - register SPI master or slave controller |
| * @ctlr: initialized master, originally from spi_alloc_master() or |
| * spi_alloc_slave() |
| * Context: can sleep |
| * |
| * SPI controllers connect to their drivers using some non-SPI bus, |
| * such as the platform bus. The final stage of probe() in that code |
| * includes calling spi_register_controller() to hook up to this SPI bus glue. |
| * |
| * SPI controllers use board specific (often SOC specific) bus numbers, |
| * and board-specific addressing for SPI devices combines those numbers |
| * with chip select numbers. Since SPI does not directly support dynamic |
| * device identification, boards need configuration tables telling which |
| * chip is at which address. |
| * |
| * This must be called from context that can sleep. It returns zero on |
| * success, else a negative error code (dropping the controller's refcount). |
| * After a successful return, the caller is responsible for calling |
| * spi_unregister_controller(). |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| int spi_register_controller(struct spi_controller *ctlr) |
| { |
| struct device *dev = ctlr->dev.parent; |
| struct boardinfo *bi; |
| int status; |
| int id, first_dynamic; |
| |
| if (!dev) |
| return -ENODEV; |
| |
| /* |
| * Make sure all necessary hooks are implemented before registering |
| * the SPI controller. |
| */ |
| status = spi_controller_check_ops(ctlr); |
| if (status) |
| return status; |
| |
| if (ctlr->bus_num >= 0) { |
| /* devices with a fixed bus num must check-in with the num */ |
| mutex_lock(&board_lock); |
| id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, |
| ctlr->bus_num + 1, GFP_KERNEL); |
| mutex_unlock(&board_lock); |
| if (WARN(id < 0, "couldn't get idr")) |
| return id == -ENOSPC ? -EBUSY : id; |
| ctlr->bus_num = id; |
| } else if (ctlr->dev.of_node) { |
| /* allocate dynamic bus number using Linux idr */ |
| id = of_alias_get_id(ctlr->dev.of_node, "spi"); |
| if (id >= 0) { |
| ctlr->bus_num = id; |
| mutex_lock(&board_lock); |
| id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, |
| ctlr->bus_num + 1, GFP_KERNEL); |
| mutex_unlock(&board_lock); |
| if (WARN(id < 0, "couldn't get idr")) |
| return id == -ENOSPC ? -EBUSY : id; |
| } |
| } |
| if (ctlr->bus_num < 0) { |
| first_dynamic = of_alias_get_highest_id("spi"); |
| if (first_dynamic < 0) |
| first_dynamic = 0; |
| else |
| first_dynamic++; |
| |
| mutex_lock(&board_lock); |
| id = idr_alloc(&spi_master_idr, ctlr, first_dynamic, |
| 0, GFP_KERNEL); |
| mutex_unlock(&board_lock); |
| if (WARN(id < 0, "couldn't get idr")) |
| return id; |
| ctlr->bus_num = id; |
| } |
| INIT_LIST_HEAD(&ctlr->queue); |
| spin_lock_init(&ctlr->queue_lock); |
| spin_lock_init(&ctlr->bus_lock_spinlock); |
| mutex_init(&ctlr->bus_lock_mutex); |
| mutex_init(&ctlr->io_mutex); |
| ctlr->bus_lock_flag = 0; |
| init_completion(&ctlr->xfer_completion); |
| if (!ctlr->max_dma_len) |
| ctlr->max_dma_len = INT_MAX; |
| |
| /* register the device, then userspace will see it. |
| * registration fails if the bus ID is in use. |
| */ |
| dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num); |
| |
| if (!spi_controller_is_slave(ctlr)) { |
| if (ctlr->use_gpio_descriptors) { |
| status = spi_get_gpio_descs(ctlr); |
| if (status) |
| goto free_bus_id; |
| /* |
| * A controller using GPIO descriptors always |
| * supports SPI_CS_HIGH if need be. |
| */ |
| ctlr->mode_bits |= SPI_CS_HIGH; |
| } else { |
| /* Legacy code path for GPIOs from DT */ |
| status = of_spi_get_gpio_numbers(ctlr); |
| if (status) |
| goto free_bus_id; |
| } |
| } |
| |
| /* |
| * Even if it's just one always-selected device, there must |
| * be at least one chipselect. |
| */ |
| if (!ctlr->num_chipselect) { |
| status = -EINVAL; |
| goto free_bus_id; |
| } |
| |
| status = device_add(&ctlr->dev); |
| if (status < 0) |
| goto free_bus_id; |
| dev_dbg(dev, "registered %s %s\n", |
| spi_controller_is_slave(ctlr) ? "slave" : "master", |
| dev_name(&ctlr->dev)); |
| |
| /* |
| * If we're using a queued driver, start the queue. Note that we don't |
| * need the queueing logic if the driver is only supporting high-level |
| * memory operations. |
| */ |
| if (ctlr->transfer) { |
| dev_info(dev, "controller is unqueued, this is deprecated\n"); |
| } else if (ctlr->transfer_one || ctlr->transfer_one_message) { |
| status = spi_controller_initialize_queue(ctlr); |
| if (status) { |
| device_del(&ctlr->dev); |
| goto free_bus_id; |
| } |
| } |
| /* add statistics */ |
| spin_lock_init(&ctlr->statistics.lock); |
| |
| mutex_lock(&board_lock); |
| list_add_tail(&ctlr->list, &spi_controller_list); |
| list_for_each_entry(bi, &board_list, list) |
| spi_match_controller_to_boardinfo(ctlr, &bi->board_info); |
| mutex_unlock(&board_lock); |
| |
| /* Register devices from the device tree and ACPI */ |
| of_register_spi_devices(ctlr); |
| acpi_register_spi_devices(ctlr); |
| return status; |
| |
| free_bus_id: |
| mutex_lock(&board_lock); |
| idr_remove(&spi_master_idr, ctlr->bus_num); |
| mutex_unlock(&board_lock); |
| return status; |
| } |
| EXPORT_SYMBOL_GPL(spi_register_controller); |
| |
| static void devm_spi_unregister(void *ctlr) |
| { |
| spi_unregister_controller(ctlr); |
| } |
| |
| /** |
| * devm_spi_register_controller - register managed SPI master or slave |
| * controller |
| * @dev: device managing SPI controller |
| * @ctlr: initialized controller, originally from spi_alloc_master() or |
| * spi_alloc_slave() |
| * Context: can sleep |
| * |
| * Register a SPI device as with spi_register_controller() which will |
| * automatically be unregistered and freed. |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| int devm_spi_register_controller(struct device *dev, |
| struct spi_controller *ctlr) |
| { |
| int ret; |
| |
| ret = spi_register_controller(ctlr); |
| if (ret) |
| return ret; |
| |
| return devm_add_action_or_reset(dev, devm_spi_unregister, ctlr); |
| } |
| EXPORT_SYMBOL_GPL(devm_spi_register_controller); |
| |
| static int __unregister(struct device *dev, void *null) |
| { |
| spi_unregister_device(to_spi_device(dev)); |
| return 0; |
| } |
| |
| /** |
| * spi_unregister_controller - unregister SPI master or slave controller |
| * @ctlr: the controller being unregistered |
| * Context: can sleep |
| * |
| * This call is used only by SPI controller drivers, which are the |
| * only ones directly touching chip registers. |
| * |
| * This must be called from context that can sleep. |
| * |
| * Note that this function also drops a reference to the controller. |
| */ |
| void spi_unregister_controller(struct spi_controller *ctlr) |
| { |
| struct spi_controller *found; |
| int id = ctlr->bus_num; |
| |
| /* Prevent addition of new devices, unregister existing ones */ |
| if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) |
| mutex_lock(&spi_add_lock); |
| |
| device_for_each_child(&ctlr->dev, NULL, __unregister); |
| |
| /* First make sure that this controller was ever added */ |
| mutex_lock(&board_lock); |
| found = idr_find(&spi_master_idr, id); |
| mutex_unlock(&board_lock); |
| if (ctlr->queued) { |
| if (spi_destroy_queue(ctlr)) |
| dev_err(&ctlr->dev, "queue remove failed\n"); |
| } |
| mutex_lock(&board_lock); |
| list_del(&ctlr->list); |
| mutex_unlock(&board_lock); |
| |
| device_del(&ctlr->dev); |
| |
| /* Release the last reference on the controller if its driver |
| * has not yet been converted to devm_spi_alloc_master/slave(). |
| */ |
| if (!ctlr->devm_allocated) |
| put_device(&ctlr->dev); |
| |
| /* free bus id */ |
| mutex_lock(&board_lock); |
| if (found == ctlr) |
| idr_remove(&spi_master_idr, id); |
| mutex_unlock(&board_lock); |
| |
| if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) |
| mutex_unlock(&spi_add_lock); |
| } |
| EXPORT_SYMBOL_GPL(spi_unregister_controller); |
| |
| int spi_controller_suspend(struct spi_controller *ctlr) |
| { |
| int ret; |
| |
| /* Basically no-ops for non-queued controllers */ |
| if (!ctlr->queued) |
| return 0; |
| |
| ret = spi_stop_queue(ctlr); |
| if (ret) |
| dev_err(&ctlr->dev, "queue stop failed\n"); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(spi_controller_suspend); |
| |
| int spi_controller_resume(struct spi_controller *ctlr) |
| { |
| int ret; |
| |
| if (!ctlr->queued) |
| return 0; |
| |
| ret = spi_start_queue(ctlr); |
| if (ret) |
| dev_err(&ctlr->dev, "queue restart failed\n"); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(spi_controller_resume); |
| |
| static int __spi_controller_match(struct device *dev, const void *data) |
| { |
| struct spi_controller *ctlr; |
| const u16 *bus_num = data; |
| |
| ctlr = container_of(dev, struct spi_controller, dev); |
| return ctlr->bus_num == *bus_num; |
| } |
| |
| /** |
| * spi_busnum_to_master - look up master associated with bus_num |
| * @bus_num: the master's bus number |
| * Context: can sleep |
| * |
| * This call may be used with devices that are registered after |
| * arch init time. It returns a refcounted pointer to the relevant |
| * spi_controller (which the caller must release), or NULL if there is |
| * no such master registered. |
| * |
| * Return: the SPI master structure on success, else NULL. |
| */ |
| struct spi_controller *spi_busnum_to_master(u16 bus_num) |
| { |
| struct device *dev; |
| struct spi_controller *ctlr = NULL; |
| |
| dev = class_find_device(&spi_master_class, NULL, &bus_num, |
| __spi_controller_match); |
| if (dev) |
| ctlr = container_of(dev, struct spi_controller, dev); |
| /* reference got in class_find_device */ |
| return ctlr; |
| } |
| EXPORT_SYMBOL_GPL(spi_busnum_to_master); |
| |
| /*-------------------------------------------------------------------------*/ |
| |
| /* Core methods for SPI resource management */ |
| |
| /** |
| * spi_res_alloc - allocate a spi resource that is life-cycle managed |
| * during the processing of a spi_message while using |
| * spi_transfer_one |
| * @spi: the spi device for which we allocate memory |
| * @release: the release code to execute for this resource |
| * @size: size to alloc and return |
| * @gfp: GFP allocation flags |
| * |
| * Return: the pointer to the allocated data |
| * |
| * This may get enhanced in the future to allocate from a memory pool |
| * of the @spi_device or @spi_controller to avoid repeated allocations. |
| */ |
| void *spi_res_alloc(struct spi_device *spi, |
| spi_res_release_t release, |
| size_t size, gfp_t gfp) |
| { |
| struct spi_res *sres; |
| |
| sres = kzalloc(sizeof(*sres) + size, gfp); |
| if (!sres) |
| return NULL; |
| |
| INIT_LIST_HEAD(&sres->entry); |
| sres->release = release; |
| |
| return sres->data; |
| } |
| EXPORT_SYMBOL_GPL(spi_res_alloc); |
| |
| /** |
| * spi_res_free - free an spi resource |
| * @res: pointer to the custom data of a resource |
| * |
| */ |
| void spi_res_free(void *res) |
| { |
| struct spi_res *sres = container_of(res, struct spi_res, data); |
| |
| if (!res) |
| return; |
| |
| WARN_ON(!list_empty(&sres->entry)); |
| kfree(sres); |
| } |
| EXPORT_SYMBOL_GPL(spi_res_free); |
| |
| /** |
| * spi_res_add - add a spi_res to the spi_message |
| * @message: the spi message |
| * @res: the spi_resource |
| */ |
| void spi_res_add(struct spi_message *message, void *res) |
| { |
| struct spi_res *sres = container_of(res, struct spi_res, data); |
| |
| WARN_ON(!list_empty(&sres->entry)); |
| list_add_tail(&sres->entry, &message->resources); |
| } |
| EXPORT_SYMBOL_GPL(spi_res_add); |
| |
| /** |
| * spi_res_release - release all spi resources for this message |
| * @ctlr: the @spi_controller |
| * @message: the @spi_message |
| */ |
| void spi_res_release(struct spi_controller *ctlr, struct spi_message *message) |
| { |
| struct spi_res *res, *tmp; |
| |
| list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) { |
| if (res->release) |
| res->release(ctlr, message, res->data); |
| |
| list_del(&res->entry); |
| |
| kfree(res); |
| } |
| } |
| EXPORT_SYMBOL_GPL(spi_res_release); |
| |
| /*-------------------------------------------------------------------------*/ |
| |
| /* Core methods for spi_message alterations */ |
| |
| static void __spi_replace_transfers_release(struct spi_controller *ctlr, |
| struct spi_message *msg, |
| void *res) |
| { |
| struct spi_replaced_transfers *rxfer = res; |
| size_t i; |
| |
| /* call extra callback if requested */ |
| if (rxfer->release) |
| rxfer->release(ctlr, msg, res); |
| |
| /* insert replaced transfers back into the message */ |
| list_splice(&rxfer->replaced_transfers, rxfer->replaced_after); |
| |
| /* remove the formerly inserted entries */ |
| for (i = 0; i < rxfer->inserted; i++) |
| list_del(&rxfer->inserted_transfers[i].transfer_list); |
| } |
| |
| /** |
| * spi_replace_transfers - replace transfers with several transfers |
| * and register change with spi_message.resources |
| * @msg: the spi_message we work upon |
| * @xfer_first: the first spi_transfer we want to replace |
| * @remove: number of transfers to remove |
| * @insert: the number of transfers we want to insert instead |
| * @release: extra release code necessary in some circumstances |
| * @extradatasize: extra data to allocate (with alignment guarantees |
| * of struct @spi_transfer) |
| * @gfp: gfp flags |
| * |
| * Returns: pointer to @spi_replaced_transfers, |
| * PTR_ERR(...) in case of errors. |
| */ |
| struct spi_replaced_transfers *spi_replace_transfers( |
| struct spi_message *msg, |
| struct spi_transfer *xfer_first, |
| size_t remove, |
| size_t insert, |
| spi_replaced_release_t release, |
| size_t extradatasize, |
| gfp_t gfp) |
| { |
| struct spi_replaced_transfers *rxfer; |
| struct spi_transfer *xfer; |
| size_t i; |
| |
| /* allocate the structure using spi_res */ |
| rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release, |
| struct_size(rxfer, inserted_transfers, insert) |
| + extradatasize, |
| gfp); |
| if (!rxfer) |
| return ERR_PTR(-ENOMEM); |
| |
| /* the release code to invoke before running the generic release */ |
| rxfer->release = release; |
| |
| /* assign extradata */ |
| if (extradatasize) |
| rxfer->extradata = |
| &rxfer->inserted_transfers[insert]; |
| |
| /* init the replaced_transfers list */ |
| INIT_LIST_HEAD(&rxfer->replaced_transfers); |
| |
| /* assign the list_entry after which we should reinsert |
| * the @replaced_transfers - it may be spi_message.messages! |
| */ |
| rxfer->replaced_after = xfer_first->transfer_list.prev; |
| |
| /* remove the requested number of transfers */ |
| for (i = 0; i < remove; i++) { |
| /* if the entry after replaced_after it is msg->transfers |
| * then we have been requested to remove more transfers |
| * than are in the list |
| */ |
| if (rxfer->replaced_after->next == &msg->transfers) { |
| dev_err(&msg->spi->dev, |
| "requested to remove more spi_transfers than are available\n"); |
| /* insert replaced transfers back into the message */ |
| list_splice(&rxfer->replaced_transfers, |
| rxfer->replaced_after); |
| |
| /* free the spi_replace_transfer structure */ |
| spi_res_free(rxfer); |
| |
| /* and return with an error */ |
| return ERR_PTR(-EINVAL); |
| } |
| |
| /* remove the entry after replaced_after from list of |
| * transfers and add it to list of replaced_transfers |
| */ |
| list_move_tail(rxfer->replaced_after->next, |
| &rxfer->replaced_transfers); |
| } |
| |
| /* create copy of the given xfer with identical settings |
| * based on the first transfer to get removed |
| */ |
| for (i = 0; i < insert; i++) { |
| /* we need to run in reverse order */ |
| xfer = &rxfer->inserted_transfers[insert - 1 - i]; |
| |
| /* copy all spi_transfer data */ |
| memcpy(xfer, xfer_first, sizeof(*xfer)); |
| |
| /* add to list */ |
| list_add(&xfer->transfer_list, rxfer->replaced_after); |
| |
| /* clear cs_change and delay for all but the last */ |
| if (i) { |
| xfer->cs_change = false; |
| xfer->delay.value = 0; |
| } |
| } |
| |
| /* set up inserted */ |
| rxfer->inserted = insert; |
| |
| /* and register it with spi_res/spi_message */ |
| spi_res_add(msg, rxfer); |
| |
| return rxfer; |
| } |
| EXPORT_SYMBOL_GPL(spi_replace_transfers); |
| |
| static int __spi_split_transfer_maxsize(struct spi_controller *ctlr, |
| struct spi_message *msg, |
| struct spi_transfer **xferp, |
| size_t maxsize, |
| gfp_t gfp) |
| { |
| struct spi_transfer *xfer = *xferp, *xfers; |
| struct spi_replaced_transfers *srt; |
| size_t offset; |
| size_t count, i; |
| |
| /* calculate how many we have to replace */ |
| count = DIV_ROUND_UP(xfer->len, maxsize); |
| |
| /* create replacement */ |
| srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp); |
| if (IS_ERR(srt)) |
| return PTR_ERR(srt); |
| xfers = srt->inserted_transfers; |
| |
| /* now handle each of those newly inserted spi_transfers |
| * note that the replacements spi_transfers all are preset |
| * to the same values as *xferp, so tx_buf, rx_buf and len |
| * are all identical (as well as most others) |
| * so we just have to fix up len and the pointers. |
| * |
| * this also includes support for the depreciated |
| * spi_message.is_dma_mapped interface |
| */ |
| |
| /* the first transfer just needs the length modified, so we |
| * run it outside the loop |
| */ |
| xfers[0].len = min_t(size_t, maxsize, xfer[0].len); |
| |
| /* all the others need rx_buf/tx_buf also set */ |
| for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) { |
| /* update rx_buf, tx_buf and dma */ |
| if (xfers[i].rx_buf) |
| xfers[i].rx_buf += offset; |
| if (xfers[i].rx_dma) |
| xfers[i].rx_dma += offset; |
| if (xfers[i].tx_buf) |
| xfers[i].tx_buf += offset; |
| if (xfers[i].tx_dma) |
| xfers[i].tx_dma += offset; |
| |
| /* update length */ |
| xfers[i].len = min(maxsize, xfers[i].len - offset); |
| } |
| |
| /* we set up xferp to the last entry we have inserted, |
| * so that we skip those already split transfers |
| */ |
| *xferp = &xfers[count - 1]; |
| |
| /* increment statistics counters */ |
| SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, |
| transfers_split_maxsize); |
| SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics, |
| transfers_split_maxsize); |
| |
| return 0; |
| } |
| |
| /** |
| * spi_split_transfers_maxsize - split spi transfers into multiple transfers |
| * when an individual transfer exceeds a |
| * certain size |
| * @ctlr: the @spi_controller for this transfer |
| * @msg: the @spi_message to transform |
| * @maxsize: the maximum when to apply this |
| * @gfp: GFP allocation flags |
| * |
| * Return: status of transformation |
| */ |
| int spi_split_transfers_maxsize(struct spi_controller *ctlr, |
| struct spi_message *msg, |
| size_t maxsize, |
| gfp_t gfp) |
| { |
| struct spi_transfer *xfer; |
| int ret; |
| |
| /* iterate over the transfer_list, |
| * but note that xfer is advanced to the last transfer inserted |
| * to avoid checking sizes again unnecessarily (also xfer does |
| * potentiall belong to a different list by the time the |
| * replacement has happened |
| */ |
| list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| if (xfer->len > maxsize) { |
| ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer, |
| maxsize, gfp); |
| if (ret) |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize); |
| |
| /*-------------------------------------------------------------------------*/ |
| |
| /* Core methods for SPI controller protocol drivers. Some of the |
| * other core methods are currently defined as inline functions. |
| */ |
| |
| static int __spi_validate_bits_per_word(struct spi_controller *ctlr, |
| u8 bits_per_word) |
| { |
| if (ctlr->bits_per_word_mask) { |
| /* Only 32 bits fit in the mask */ |
| if (bits_per_word > 32) |
| return -EINVAL; |
| if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word))) |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * spi_setup - setup SPI mode and clock rate |
| * @spi: the device whose settings are being modified |
| * Context: can sleep, and no requests are queued to the device |
| * |
| * SPI protocol drivers may need to update the transfer mode if the |
| * device doesn't work with its default. They may likewise need |
| * to update clock rates or word sizes from initial values. This function |
| * changes those settings, and must be called from a context that can sleep. |
| * Except for SPI_CS_HIGH, which takes effect immediately, the changes take |
| * effect the next time the device is selected and data is transferred to |
| * or from it. When this function returns, the spi device is deselected. |
| * |
| * Note that this call will fail if the protocol driver specifies an option |
| * that the underlying controller or its driver does not support. For |
| * example, not all hardware supports wire transfers using nine bit words, |
| * LSB-first wire encoding, or active-high chipselects. |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| int spi_setup(struct spi_device *spi) |
| { |
| unsigned bad_bits, ugly_bits; |
| int status; |
| |
| /* |
| * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO |
| * are set at the same time |
| */ |
| if ((hweight_long(spi->mode & |
| (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) || |
| (hweight_long(spi->mode & |
| (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) { |
| dev_err(&spi->dev, |
| "setup: can not select any two of dual, quad and no-rx/tx at the same time\n"); |
| return -EINVAL; |
| } |
| /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden |
| */ |
| if ((spi->mode & SPI_3WIRE) && (spi->mode & |
| (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | |
| SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))) |
| return -EINVAL; |
| /* help drivers fail *cleanly* when they need options |
| * that aren't supported with their current controller |
| * SPI_CS_WORD has a fallback software implementation, |
| * so it is ignored here. |
| */ |
| bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD | |
| SPI_NO_TX | SPI_NO_RX); |
| /* nothing prevents from working with active-high CS in case if it |
| * is driven by GPIO. |
| */ |
| if (gpio_is_valid(spi->cs_gpio)) |
| bad_bits &= ~SPI_CS_HIGH; |
| ugly_bits = bad_bits & |
| (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | |
| SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL); |
| if (ugly_bits) { |
| dev_warn(&spi->dev, |
| "setup: ignoring unsupported mode bits %x\n", |
| ugly_bits); |
| spi->mode &= ~ugly_bits; |
| bad_bits &= ~ugly_bits; |
| } |
| if (bad_bits) { |
| dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
| bad_bits); |
| return -EINVAL; |
| } |
| |
| if (!spi->bits_per_word) |
| spi->bits_per_word = 8; |
| |
| status = __spi_validate_bits_per_word(spi->controller, |
| spi->bits_per_word); |
| if (status) |
| return status; |
| |
| if (spi->controller->max_speed_hz && |
| (!spi->max_speed_hz || |
| spi->max_speed_hz > spi->controller->max_speed_hz)) |
| spi->max_speed_hz = spi->controller->max_speed_hz; |
| |
| mutex_lock(&spi->controller->io_mutex); |
| |
| if (spi->controller->setup) { |
| status = spi->controller->setup(spi); |
| if (status) { |
| mutex_unlock(&spi->controller->io_mutex); |
| dev_err(&spi->controller->dev, "Failed to setup device: %d\n", |
| status); |
| return status; |
| } |
| } |
| |
| if (spi->controller->auto_runtime_pm && spi->controller->set_cs) { |
| status = pm_runtime_get_sync(spi->controller->dev.parent); |
| if (status < 0) { |
| mutex_unlock(&spi->controller->io_mutex); |
| pm_runtime_put_noidle(spi->controller->dev.parent); |
| dev_err(&spi->controller->dev, "Failed to power device: %d\n", |
| status); |
| return status; |
| } |
| |
| /* |
| * We do not want to return positive value from pm_runtime_get, |
| * there are many instances of devices calling spi_setup() and |
| * checking for a non-zero return value instead of a negative |
| * return value. |
| */ |
| status = 0; |
| |
| spi_set_cs(spi, false, true); |
| pm_runtime_mark_last_busy(spi->controller->dev.parent); |
| pm_runtime_put_autosuspend(spi->controller->dev.parent); |
| } else { |
| spi_set_cs(spi, false, true); |
| } |
| |
| mutex_unlock(&spi->controller->io_mutex); |
| |
| if (spi->rt && !spi->controller->rt) { |
| spi->controller->rt = true; |
| spi_set_thread_rt(spi->controller); |
| } |
| |
| dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", |
| (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), |
| (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", |
| (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", |
| (spi->mode & SPI_3WIRE) ? "3wire, " : "", |
| (spi->mode & SPI_LOOP) ? "loopback, " : "", |
| spi->bits_per_word, spi->max_speed_hz, |
| status); |
| |
| return status; |
| } |
| EXPORT_SYMBOL_GPL(spi_setup); |
| |
| /** |
| * spi_set_cs_timing - configure CS setup, hold, and inactive delays |
| * @spi: the device that requires specific CS timing configuration |
| * @setup: CS setup time specified via @spi_delay |
| * @hold: CS hold time specified via @spi_delay |
| * @inactive: CS inactive delay between transfers specified via @spi_delay |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup, |
| struct spi_delay *hold, struct spi_delay *inactive) |
| { |
| struct device *parent = spi->controller->dev.parent; |
| size_t len; |
| int status; |
| |
| if (spi->controller->set_cs_timing && |
| !(spi->cs_gpiod || gpio_is_valid(spi->cs_gpio))) { |
| mutex_lock(&spi->controller->io_mutex); |
| |
| if (spi->controller->auto_runtime_pm) { |
| status = pm_runtime_get_sync(parent); |
| if (status < 0) { |
| mutex_unlock(&spi->controller->io_mutex); |
| pm_runtime_put_noidle(parent); |
| dev_err(&spi->controller->dev, "Failed to power device: %d\n", |
| status); |
| return status; |
| } |
| |
| status = spi->controller->set_cs_timing(spi, setup, |
| hold, inactive); |
| pm_runtime_mark_last_busy(parent); |
| pm_runtime_put_autosuspend(parent); |
| } else { |
| status = spi->controller->set_cs_timing(spi, setup, hold, |
| inactive); |
| } |
| |
| mutex_unlock(&spi->controller->io_mutex); |
| return status; |
| } |
| |
| if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) || |
| (hold && hold->unit == SPI_DELAY_UNIT_SCK) || |
| (inactive && inactive->unit == SPI_DELAY_UNIT_SCK)) { |
| dev_err(&spi->dev, |
| "Clock-cycle delays for CS not supported in SW mode\n"); |
| return -ENOTSUPP; |
| } |
| |
| len = sizeof(struct spi_delay); |
| |
| /* copy delays to controller */ |
| if (setup) |
| memcpy(&spi->controller->cs_setup, setup, len); |
| else |
| memset(&spi->controller->cs_setup, 0, len); |
| |
| if (hold) |
| memcpy(&spi->controller->cs_hold, hold, len); |
| else |
| memset(&spi->controller->cs_hold, 0, len); |
| |
| if (inactive) |
| memcpy(&spi->controller->cs_inactive, inactive, len); |
| else |
| memset(&spi->controller->cs_inactive, 0, len); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(spi_set_cs_timing); |
| |
| static int _spi_xfer_word_delay_update(struct spi_transfer *xfer, |
| struct spi_device *spi) |
| { |
| int delay1, delay2; |
| |
| delay1 = spi_delay_to_ns(&xfer->word_delay, xfer); |
| if (delay1 < 0) |
| return delay1; |
| |
| delay2 = spi_delay_to_ns(&spi->word_delay, xfer); |
| if (delay2 < 0) |
| return delay2; |
| |
| if (delay1 < delay2) |
| memcpy(&xfer->word_delay, &spi->word_delay, |
| sizeof(xfer->word_delay)); |
| |
| return 0; |
| } |
| |
| static int __spi_validate(struct spi_device *spi, struct spi_message *message) |
| { |
| struct spi_controller *ctlr = spi->controller; |
| struct spi_transfer *xfer; |
| int w_size; |
| |
| if (list_empty(&message->transfers)) |
| return -EINVAL; |
| |
| /* If an SPI controller does not support toggling the CS line on each |
| * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO |
| * for the CS line, we can emulate the CS-per-word hardware function by |
| * splitting transfers into one-word transfers and ensuring that |
| * cs_change is set for each transfer. |
| */ |
| if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || |
| spi->cs_gpiod || |
| gpio_is_valid(spi->cs_gpio))) { |
| size_t maxsize; |
| int ret; |
| |
| maxsize = (spi->bits_per_word + 7) / 8; |
| |
| /* spi_split_transfers_maxsize() requires message->spi */ |
| message->spi = spi; |
| |
| ret = spi_split_transfers_maxsize(ctlr, message, maxsize, |
| GFP_KERNEL); |
| if (ret) |
| return ret; |
| |
| list_for_each_entry(xfer, &message->transfers, transfer_list) { |
| /* don't change cs_change on the last entry in the list */ |
| if (list_is_last(&xfer->transfer_list, &message->transfers)) |
| break; |
| xfer->cs_change = 1; |
| } |
| } |
| |
| /* Half-duplex links include original MicroWire, and ones with |
| * only one data pin like SPI_3WIRE (switches direction) or where |
| * either MOSI or MISO is missing. They can also be caused by |
| * software limitations. |
| */ |
| if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) || |
| (spi->mode & SPI_3WIRE)) { |
| unsigned flags = ctlr->flags; |
| |
| list_for_each_entry(xfer, &message->transfers, transfer_list) { |
| if (xfer->rx_buf && xfer->tx_buf) |
| return -EINVAL; |
| if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf) |
| return -EINVAL; |
| if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf) |
| return -EINVAL; |
| } |
| } |
| |
| /** |
| * Set transfer bits_per_word and max speed as spi device default if |
| * it is not set for this transfer. |
| * Set transfer tx_nbits and rx_nbits as single transfer default |
| * (SPI_NBITS_SINGLE) if it is not set for this transfer. |
| * Ensure transfer word_delay is at least as long as that required by |
| * device itself. |
| */ |
| message->frame_length = 0; |
| list_for_each_entry(xfer, &message->transfers, transfer_list) { |
| xfer->effective_speed_hz = 0; |
| message->frame_length += xfer->len; |
| if (!xfer->bits_per_word) |
| xfer->bits_per_word = spi->bits_per_word; |
| |
| if (!xfer->speed_hz) |
| xfer->speed_hz = spi->max_speed_hz; |
| |
| if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz) |
| xfer->speed_hz = ctlr->max_speed_hz; |
| |
| if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word)) |
| return -EINVAL; |
| |
| /* |
| * SPI transfer length should be multiple of SPI word size |
| * where SPI word size should be power-of-two multiple |
| */ |
| if (xfer->bits_per_word <= 8) |
| w_size = 1; |
| else if (xfer->bits_per_word <= 16) |
| w_size = 2; |
| else |
| w_size = 4; |
| |
| /* No partial transfers accepted */ |
| if (xfer->len % w_size) |
| return -EINVAL; |
| |
| if (xfer->speed_hz && ctlr->min_speed_hz && |
| xfer->speed_hz < ctlr->min_speed_hz) |
| return -EINVAL; |
| |
| if (xfer->tx_buf && !xfer->tx_nbits) |
| xfer->tx_nbits = SPI_NBITS_SINGLE; |
| if (xfer->rx_buf && !xfer->rx_nbits) |
| xfer->rx_nbits = SPI_NBITS_SINGLE; |
| /* check transfer tx/rx_nbits: |
| * 1. check the value matches one of single, dual and quad |
| * 2. check tx/rx_nbits match the mode in spi_device |
| */ |
| if (xfer->tx_buf) { |
| if (spi->mode & SPI_NO_TX) |
| return -EINVAL; |
| if (xfer->tx_nbits != SPI_NBITS_SINGLE && |
| xfer->tx_nbits != SPI_NBITS_DUAL && |
| xfer->tx_nbits != SPI_NBITS_QUAD) |
| return -EINVAL; |
| if ((xfer->tx_nbits == SPI_NBITS_DUAL) && |
| !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) |
| return -EINVAL; |
| if ((xfer->tx_nbits == SPI_NBITS_QUAD) && |
| !(spi->mode & SPI_TX_QUAD)) |
| return -EINVAL; |
| } |
| /* check transfer rx_nbits */ |
| if (xfer->rx_buf) { |
| if (spi->mode & SPI_NO_RX) |
| return -EINVAL; |
| if (xfer->rx_nbits != SPI_NBITS_SINGLE && |
| xfer->rx_nbits != SPI_NBITS_DUAL && |
| xfer->rx_nbits != SPI_NBITS_QUAD) |
| return -EINVAL; |
| if ((xfer->rx_nbits == SPI_NBITS_DUAL) && |
| !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) |
| return -EINVAL; |
| if ((xfer->rx_nbits == SPI_NBITS_QUAD) && |
| !(spi->mode & SPI_RX_QUAD)) |
| return -EINVAL; |
| } |
| |
| if (_spi_xfer_word_delay_update(xfer, spi)) |
| return -EINVAL; |
| } |
| |
| message->status = -EINPROGRESS; |
| |
| return 0; |
| } |
| |
| static int __spi_async(struct spi_device *spi, struct spi_message *message) |
| { |
| struct spi_controller *ctlr = spi->controller; |
| struct spi_transfer *xfer; |
| |
| /* |
| * Some controllers do not support doing regular SPI transfers. Return |
| * ENOTSUPP when this is the case. |
| */ |
| if (!ctlr->transfer) |
| return -ENOTSUPP; |
| |
| message->spi = spi; |
| |
| SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async); |
| SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async); |
| |
| trace_spi_message_submit(message); |
| |
| if (!ctlr->ptp_sts_supported) { |
| list_for_each_entry(xfer, &message->transfers, transfer_list) { |
| xfer->ptp_sts_word_pre = 0; |
| ptp_read_system_prets(xfer->ptp_sts); |
| } |
| } |
| |
| return ctlr->transfer(spi, message); |
| } |
| |
| /** |
| * spi_async - asynchronous SPI transfer |
| * @spi: device with which data will be exchanged |
| * @message: describes the data transfers, including completion callback |
| * Context: any (irqs may be blocked, etc) |
| * |
| * This call may be used in_irq and other contexts which can't sleep, |
| * as well as from task contexts which can sleep. |
| * |
| * The completion callback is invoked in a context which can't sleep. |
| * Before that invocation, the value of message->status is undefined. |
| * When the callback is issued, message->status holds either zero (to |
| * indicate complete success) or a negative error code. After that |
| * callback returns, the driver which issued the transfer request may |
| * deallocate the associated memory; it's no longer in use by any SPI |
| * core or controller driver code. |
| * |
| * Note that although all messages to a spi_device are handled in |
| * FIFO order, messages may go to different devices in other orders. |
| * Some device might be higher priority, or have various "hard" access |
| * time requirements, for example. |
| * |
| * On detection of any fault during the transfer, processing of |
| * the entire message is aborted, and the device is deselected. |
| * Until returning from the associated message completion callback, |
| * no other spi_message queued to that device will be processed. |
| * (This rule applies equally to all the synchronous transfer calls, |
| * which are wrappers around this core asynchronous primitive.) |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| int spi_async(struct spi_device *spi, struct spi_message *message) |
| { |
| struct spi_controller *ctlr = spi->controller; |
| int ret; |
| unsigned long flags; |
| |
| ret = __spi_validate(spi, message); |
| if (ret != 0) |
| return ret; |
| |
| spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); |
| |
| if (ctlr->bus_lock_flag) |
| ret = -EBUSY; |
| else |
| ret = __spi_async(spi, message); |
| |
| spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(spi_async); |
| |
| /** |
| * spi_async_locked - version of spi_async with exclusive bus usage |
| * @spi: device with which data will be exchanged |
| * @message: describes the data transfers, including completion callback |
| * Context: any (irqs may be blocked, etc) |
| * |
| * This call may be used in_irq and other contexts which can't sleep, |
| * as well as from task contexts which can sleep. |
| * |
| * The completion callback is invoked in a context which can't sleep. |
| * Before that invocation, the value of message->status is undefined. |
| * When the callback is issued, message->status holds either zero (to |
| * indicate complete success) or a negative error code. After that |
| * callback returns, the driver which issued the transfer request may |
| * deallocate the associated memory; it's no longer in use by any SPI |
| * core or controller driver code. |
| * |
| * Note that although all messages to a spi_device are handled in |
| * FIFO order, messages may go to different devices in other orders. |
| * Some device might be higher priority, or have various "hard" access |
| * time requirements, for example. |
| * |
| * On detection of any fault during the transfer, processing of |
| * the entire message is aborted, and the device is deselected. |
| * Until returning from the associated message completion callback, |
| * no other spi_message queued to that device will be processed. |
| * (This rule applies equally to all the synchronous transfer calls, |
| * which are wrappers around this core asynchronous primitive.) |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| int spi_async_locked(struct spi_device *spi, struct spi_message *message) |
| { |
| struct spi_controller *ctlr = spi->controller; |
| int ret; |
| unsigned long flags; |
| |
| ret = __spi_validate(spi, message); |
| if (ret != 0) |
| return ret; |
| |
| spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); |
| |
| ret = __spi_async(spi, message); |
| |
| spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); |
| |
| return ret; |
| |
| } |
| EXPORT_SYMBOL_GPL(spi_async_locked); |
| |
| /*-------------------------------------------------------------------------*/ |
| |
| /* Utility methods for SPI protocol drivers, layered on |
| * top of the core. Some other utility methods are defined as |
| * inline functions. |
| */ |
| |
| static void spi_complete(void *arg) |
| { |
| complete(arg); |
| } |
| |
| static int __spi_sync(struct spi_device *spi, struct spi_message *message) |
| { |
| DECLARE_COMPLETION_ONSTACK(done); |
| int status; |
| struct spi_controller *ctlr = spi->controller; |
| unsigned long flags; |
| |
| status = __spi_validate(spi, message); |
| if (status != 0) |
| return status; |
| |
| message->complete = spi_complete; |
| message->context = &done; |
| message->spi = spi; |
| |
| SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync); |
| SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync); |
| |
| /* If we're not using the legacy transfer method then we will |
| * try to transfer in the calling context so special case. |
| * This code would be less tricky if we could remove the |
| * support for driver implemented message queues. |
| */ |
| if (ctlr->transfer == spi_queued_transfer) { |
| spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); |
| |
| trace_spi_message_submit(message); |
| |
| status = __spi_queued_transfer(spi, message, false); |
| |
| spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); |
| } else { |
| status = spi_async_locked(spi, message); |
| } |
| |
| if (status == 0) { |
| /* Push out the messages in the calling context if we |
| * can. |
| */ |
| if (ctlr->transfer == spi_queued_transfer) { |
| SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, |
| spi_sync_immediate); |
| SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, |
| spi_sync_immediate); |
| __spi_pump_messages(ctlr, false); |
| } |
| |
| wait_for_completion(&done); |
| status = message->status; |
| } |
| message->context = NULL; |
| return status; |
| } |
| |
| /** |
| * spi_sync - blocking/synchronous SPI data transfers |
| * @spi: device with which data will be exchanged |
| * @message: describes the data transfers |
| * Context: can sleep |
| * |
| * This call may only be used from a context that may sleep. The sleep |
| * is non-interruptible, and has no timeout. Low-overhead controller |
| * drivers may DMA directly into and out of the message buffers. |
| * |
| * Note that the SPI device's chip select is active during the message, |
| * and then is normally disabled between messages. Drivers for some |
| * frequently-used devices may want to minimize costs of selecting a chip, |
| * by leaving it selected in anticipation that the next message will go |
| * to the same chip. (That may increase power usage.) |
| * |
| * Also, the caller is guaranteeing that the memory associated with the |
| * message will not be freed before this call returns. |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| int spi_sync(struct spi_device *spi, struct spi_message *message) |
| { |
| int ret; |
| |
| mutex_lock(&spi->controller->bus_lock_mutex); |
| ret = __spi_sync(spi, message); |
| mutex_unlock(&spi->controller->bus_lock_mutex); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(spi_sync); |
| |
| /** |
| * spi_sync_locked - version of spi_sync with exclusive bus usage |
| * @spi: device with which data will be exchanged |
| * @message: describes the data transfers |
| * Context: can sleep |
| * |
| * This call may only be used from a context that may sleep. The sleep |
| * is non-interruptible, and has no timeout. Low-overhead controller |
| * drivers may DMA directly into and out of the message buffers. |
| * |
| * This call should be used by drivers that require exclusive access to the |
| * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must |
| * be released by a spi_bus_unlock call when the exclusive access is over. |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| int spi_sync_locked(struct spi_device *spi, struct spi_message *message) |
| { |
| return __spi_sync(spi, message); |
| } |
| EXPORT_SYMBOL_GPL(spi_sync_locked); |
| |
| /** |
| * spi_bus_lock - obtain a lock for exclusive SPI bus usage |
| * @ctlr: SPI bus master that should be locked for exclusive bus access |
| * Context: can sleep |
| * |
| * This call may only be used from a context that may sleep. The sleep |
| * is non-interruptible, and has no timeout. |
| * |
| * This call should be used by drivers that require exclusive access to the |
| * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the |
| * exclusive access is over. Data transfer must be done by spi_sync_locked |
| * and spi_async_locked calls when the SPI bus lock is held. |
| * |
| * Return: always zero. |
| */ |
| int spi_bus_lock(struct spi_controller *ctlr) |
| { |
| unsigned long flags; |
| |
| mutex_lock(&ctlr->bus_lock_mutex); |
| |
| spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); |
| ctlr->bus_lock_flag = 1; |
| spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); |
| |
| /* mutex remains locked until spi_bus_unlock is called */ |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(spi_bus_lock); |
| |
| /** |
| * spi_bus_unlock - release the lock for exclusive SPI bus usage |
| * @ctlr: SPI bus master that was locked for exclusive bus access |
| * Context: can sleep |
| * |
| * This call may only be used from a context that may sleep. The sleep |
| * is non-interruptible, and has no timeout. |
| * |
| * This call releases an SPI bus lock previously obtained by an spi_bus_lock |
| * call. |
| * |
| * Return: always zero. |
| */ |
| int spi_bus_unlock(struct spi_controller *ctlr) |
| { |
| ctlr->bus_lock_flag = 0; |
| |
| mutex_unlock(&ctlr->bus_lock_mutex); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(spi_bus_unlock); |
| |
| /* portable code must never pass more than 32 bytes */ |
| #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) |
| |
| static u8 *buf; |
| |
| /** |
| * spi_write_then_read - SPI synchronous write followed by read |
| * @spi: device with which data will be exchanged |
| * @txbuf: data to be written (need not be dma-safe) |
| * @n_tx: size of txbuf, in bytes |
| * @rxbuf: buffer into which data will be read (need not be dma-safe) |
| * @n_rx: size of rxbuf, in bytes |
| * Context: can sleep |
| * |
| * This performs a half duplex MicroWire style transaction with the |
| * device, sending txbuf and then reading rxbuf. The return value |
| * is zero for success, else a negative errno status code. |
| * This call may only be used from a context that may sleep. |
| * |
| * Parameters to this routine are always copied using a small buffer. |
| * Performance-sensitive or bulk transfer code should instead use |
| * spi_{async,sync}() calls with dma-safe buffers. |
| * |
| * Return: zero on success, else a negative error code. |
| */ |
| int spi_write_then_read(struct spi_device *spi, |
| const void *txbuf, unsigned n_tx, |
| void *rxbuf, unsigned n_rx) |
| { |
| static DEFINE_MUTEX(lock); |
| |
| int status; |
| struct spi_message message; |
| struct spi_transfer x[2]; |
| u8 *local_buf; |
| |
| /* Use preallocated DMA-safe buffer if we can. We can't avoid |
| * copying here, (as a pure convenience thing), but we can |
| * keep heap costs out of the hot path unless someone else is |
| * using the pre-allocated buffer or the transfer is too large. |
| */ |
| if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { |
| local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), |
| GFP_KERNEL | GFP_DMA); |
| if (!local_buf) |
| return -ENOMEM; |
| } else { |
| local_buf = buf; |
| } |
| |
| spi_message_init(&message); |
| memset(x, 0, sizeof(x)); |
| if (n_tx) { |
| x[0].len = n_tx; |
| spi_message_add_tail(&x[0], &message); |
| } |
| if (n_rx) { |
| x[1].len = n_rx; |
| spi_message_add_tail(&x[1], &message); |
| } |
| |
| memcpy(local_buf, txbuf, n_tx); |
| x[0].tx_buf = local_buf; |
| x[1].rx_buf = local_buf + n_tx; |
| |
| /* do the i/o */ |
| status = spi_sync(spi, &message); |
| if (status == 0) |
| memcpy(rxbuf, x[1].rx_buf, n_rx); |
| |
| if (x[0].tx_buf == buf) |
| mutex_unlock(&lock); |
| else |
| kfree(local_buf); |
| |
| return status; |
| } |
| EXPORT_SYMBOL_GPL(spi_write_then_read); |
| |
| /*-------------------------------------------------------------------------*/ |
| |
| #if IS_ENABLED(CONFIG_OF) |
| /* must call put_device() when done with returned spi_device device */ |
| struct spi_device *of_find_spi_device_by_node(struct device_node *node) |
| { |
| struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node); |
| |
| return dev ? to_spi_device(dev) : NULL; |
| } |
| EXPORT_SYMBOL_GPL(of_find_spi_device_by_node); |
| #endif /* IS_ENABLED(CONFIG_OF) */ |
| |
| #if IS_ENABLED(CONFIG_OF_DYNAMIC) |
| /* the spi controllers are not using spi_bus, so we find it with another way */ |
| static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node) |
| { |
| struct device *dev; |
| |
| dev = class_find_device_by_of_node(&spi_master_class, node); |
| if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) |
| dev = class_find_device_by_of_node(&spi_slave_class, node); |
| if (!dev) |
| return NULL; |
| |
| /* reference got in class_find_device */ |
| return container_of(dev, struct spi_controller, dev); |
| } |
| |
| static int of_spi_notify(struct notifier_block *nb, unsigned long action, |
| void *arg) |
| { |
| struct of_reconfig_data *rd = arg; |
| struct spi_controller *ctlr; |
| struct spi_device *spi; |
| |
| switch (of_reconfig_get_state_change(action, arg)) { |
| case OF_RECONFIG_CHANGE_ADD: |
| ctlr = of_find_spi_controller_by_node(rd->dn->parent); |
| if (ctlr == NULL) |
| return NOTIFY_OK; /* not for us */ |
| |
| if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { |
| put_device(&ctlr->dev); |
| return NOTIFY_OK; |
| } |
| |
| spi = of_register_spi_device(ctlr, rd->dn); |
| put_device(&ctlr->dev); |
| |
| if (IS_ERR(spi)) { |
| pr_err("%s: failed to create for '%pOF'\n", |
| __func__, rd->dn); |
| of_node_clear_flag(rd->dn, OF_POPULATED); |
| return notifier_from_errno(PTR_ERR(spi)); |
| } |
| break; |
| |
| case OF_RECONFIG_CHANGE_REMOVE: |
| /* already depopulated? */ |
| if (!of_node_check_flag(rd->dn, OF_POPULATED)) |
| return NOTIFY_OK; |
| |
| /* find our device by node */ |
| spi = of_find_spi_device_by_node(rd->dn); |
| if (spi == NULL) |
| return NOTIFY_OK; /* no? not meant for us */ |
| |
| /* unregister takes one ref away */ |
| spi_unregister_device(spi); |
| |
| /* and put the reference of the find */ |
| put_device(&spi->dev); |
| break; |
| } |
| |
| return NOTIFY_OK; |
| } |
| |
| static struct notifier_block spi_of_notifier = { |
| .notifier_call = of_spi_notify, |
| }; |
| #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ |
| extern struct notifier_block spi_of_notifier; |
| #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ |
| |
| #if IS_ENABLED(CONFIG_ACPI) |
| static int spi_acpi_controller_match(struct device *dev, const void *data) |
| { |
| return ACPI_COMPANION(dev->parent) == data; |
| } |
| |
| static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev) |
| { |
| struct device *dev; |
| |
| dev = class_find_device(&spi_master_class, NULL, adev, |
| spi_acpi_controller_match); |
| if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE)) |
| dev = class_find_device(&spi_slave_class, NULL, adev, |
| spi_acpi_controller_match); |
| if (!dev) |
| return NULL; |
| |
| return container_of(dev, struct spi_controller, dev); |
| } |
| |
| static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev) |
| { |
| struct device *dev; |
| |
| dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev); |
| return to_spi_device(dev); |
| } |
| |
| static int acpi_spi_notify(struct notifier_block *nb, unsigned long value, |
| void *arg) |
| { |
| struct acpi_device *adev = arg; |
| struct spi_controller *ctlr; |
| struct spi_device *spi; |
| |
| switch (value) { |
| case ACPI_RECONFIG_DEVICE_ADD: |
| ctlr = acpi_spi_find_controller_by_adev(adev->parent); |
| if (!ctlr) |
| break; |
| |
| acpi_register_spi_device(ctlr, adev); |
| put_device(&ctlr->dev); |
| break; |
| case ACPI_RECONFIG_DEVICE_REMOVE: |
| if (!acpi_device_enumerated(adev)) |
| break; |
| |
| spi = acpi_spi_find_device_by_adev(adev); |
| if (!spi) |
| break; |
| |
| spi_unregister_device(spi); |
| put_device(&spi->dev); |
| break; |
| } |
| |
| return NOTIFY_OK; |
| } |
| |
| static struct notifier_block spi_acpi_notifier = { |
| .notifier_call = acpi_spi_notify, |
| }; |
| #else |
| extern struct notifier_block spi_acpi_notifier; |
| #endif |
| |
| static int __init spi_init(void) |
| { |
| int status; |
| |
| buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
| if (!buf) { |
| status = -ENOMEM; |
| goto err0; |
| } |
| |
| status = bus_register(&spi_bus_type); |
| if (status < 0) |
| goto err1; |
| |
| status = class_register(&spi_master_class); |
| if (status < 0) |
| goto err2; |
| |
| if (IS_ENABLED(CONFIG_SPI_SLAVE)) { |
| status = class_register(&spi_slave_class); |
| if (status < 0) |
| goto err3; |
| } |
| |
| if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
| WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); |
| if (IS_ENABLED(CONFIG_ACPI)) |
| WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier)); |
| |
| return 0; |
| |
| err3: |
| class_unregister(&spi_master_class); |
| err2: |
| bus_unregister(&spi_bus_type); |
| err1: |
| kfree(buf); |
| buf = NULL; |
| err0: |
| return status; |
| } |
| |
| /* board_info is normally registered in arch_initcall(), |
| * but even essential drivers wait till later |
| * |
| * REVISIT only boardinfo really needs static linking. the rest (device and |
| * driver registration) _could_ be dynamically linked (modular) ... costs |
| * include needing to have boardinfo data structures be much more public. |
| */ |
| postcore_initcall(spi_init); |