| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * nvmem framework core. |
| * |
| * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org> |
| * Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com> |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/export.h> |
| #include <linux/fs.h> |
| #include <linux/idr.h> |
| #include <linux/init.h> |
| #include <linux/kref.h> |
| #include <linux/module.h> |
| #include <linux/nvmem-consumer.h> |
| #include <linux/nvmem-provider.h> |
| #include <linux/gpio/consumer.h> |
| #include <linux/of.h> |
| #include <linux/slab.h> |
| |
| struct nvmem_device { |
| struct module *owner; |
| struct device dev; |
| int stride; |
| int word_size; |
| int id; |
| struct kref refcnt; |
| size_t size; |
| bool read_only; |
| bool root_only; |
| int flags; |
| enum nvmem_type type; |
| struct bin_attribute eeprom; |
| struct device *base_dev; |
| struct list_head cells; |
| const struct nvmem_keepout *keepout; |
| unsigned int nkeepout; |
| nvmem_reg_read_t reg_read; |
| nvmem_reg_write_t reg_write; |
| nvmem_cell_post_process_t cell_post_process; |
| struct gpio_desc *wp_gpio; |
| void *priv; |
| }; |
| |
| #define to_nvmem_device(d) container_of(d, struct nvmem_device, dev) |
| |
| #define FLAG_COMPAT BIT(0) |
| struct nvmem_cell_entry { |
| const char *name; |
| int offset; |
| int bytes; |
| int bit_offset; |
| int nbits; |
| struct device_node *np; |
| struct nvmem_device *nvmem; |
| struct list_head node; |
| }; |
| |
| struct nvmem_cell { |
| struct nvmem_cell_entry *entry; |
| const char *id; |
| }; |
| |
| static DEFINE_MUTEX(nvmem_mutex); |
| static DEFINE_IDA(nvmem_ida); |
| |
| static DEFINE_MUTEX(nvmem_cell_mutex); |
| static LIST_HEAD(nvmem_cell_tables); |
| |
| static DEFINE_MUTEX(nvmem_lookup_mutex); |
| static LIST_HEAD(nvmem_lookup_list); |
| |
| static BLOCKING_NOTIFIER_HEAD(nvmem_notifier); |
| |
| static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset, |
| void *val, size_t bytes) |
| { |
| if (nvmem->reg_read) |
| return nvmem->reg_read(nvmem->priv, offset, val, bytes); |
| |
| return -EINVAL; |
| } |
| |
| static int __nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset, |
| void *val, size_t bytes) |
| { |
| int ret; |
| |
| if (nvmem->reg_write) { |
| gpiod_set_value_cansleep(nvmem->wp_gpio, 0); |
| ret = nvmem->reg_write(nvmem->priv, offset, val, bytes); |
| gpiod_set_value_cansleep(nvmem->wp_gpio, 1); |
| return ret; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static int nvmem_access_with_keepouts(struct nvmem_device *nvmem, |
| unsigned int offset, void *val, |
| size_t bytes, int write) |
| { |
| |
| unsigned int end = offset + bytes; |
| unsigned int kend, ksize; |
| const struct nvmem_keepout *keepout = nvmem->keepout; |
| const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout; |
| int rc; |
| |
| /* |
| * Skip all keepouts before the range being accessed. |
| * Keepouts are sorted. |
| */ |
| while ((keepout < keepoutend) && (keepout->end <= offset)) |
| keepout++; |
| |
| while ((offset < end) && (keepout < keepoutend)) { |
| /* Access the valid portion before the keepout. */ |
| if (offset < keepout->start) { |
| kend = min(end, keepout->start); |
| ksize = kend - offset; |
| if (write) |
| rc = __nvmem_reg_write(nvmem, offset, val, ksize); |
| else |
| rc = __nvmem_reg_read(nvmem, offset, val, ksize); |
| |
| if (rc) |
| return rc; |
| |
| offset += ksize; |
| val += ksize; |
| } |
| |
| /* |
| * Now we're aligned to the start of this keepout zone. Go |
| * through it. |
| */ |
| kend = min(end, keepout->end); |
| ksize = kend - offset; |
| if (!write) |
| memset(val, keepout->value, ksize); |
| |
| val += ksize; |
| offset += ksize; |
| keepout++; |
| } |
| |
| /* |
| * If we ran out of keepouts but there's still stuff to do, send it |
| * down directly |
| */ |
| if (offset < end) { |
| ksize = end - offset; |
| if (write) |
| return __nvmem_reg_write(nvmem, offset, val, ksize); |
| else |
| return __nvmem_reg_read(nvmem, offset, val, ksize); |
| } |
| |
| return 0; |
| } |
| |
| static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset, |
| void *val, size_t bytes) |
| { |
| if (!nvmem->nkeepout) |
| return __nvmem_reg_read(nvmem, offset, val, bytes); |
| |
| return nvmem_access_with_keepouts(nvmem, offset, val, bytes, false); |
| } |
| |
| static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset, |
| void *val, size_t bytes) |
| { |
| if (!nvmem->nkeepout) |
| return __nvmem_reg_write(nvmem, offset, val, bytes); |
| |
| return nvmem_access_with_keepouts(nvmem, offset, val, bytes, true); |
| } |
| |
| #ifdef CONFIG_NVMEM_SYSFS |
| static const char * const nvmem_type_str[] = { |
| [NVMEM_TYPE_UNKNOWN] = "Unknown", |
| [NVMEM_TYPE_EEPROM] = "EEPROM", |
| [NVMEM_TYPE_OTP] = "OTP", |
| [NVMEM_TYPE_BATTERY_BACKED] = "Battery backed", |
| [NVMEM_TYPE_FRAM] = "FRAM", |
| }; |
| |
| #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| static struct lock_class_key eeprom_lock_key; |
| #endif |
| |
| static ssize_t type_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct nvmem_device *nvmem = to_nvmem_device(dev); |
| |
| return sprintf(buf, "%s\n", nvmem_type_str[nvmem->type]); |
| } |
| |
| static DEVICE_ATTR_RO(type); |
| |
| static struct attribute *nvmem_attrs[] = { |
| &dev_attr_type.attr, |
| NULL, |
| }; |
| |
| static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj, |
| struct bin_attribute *attr, char *buf, |
| loff_t pos, size_t count) |
| { |
| struct device *dev; |
| struct nvmem_device *nvmem; |
| int rc; |
| |
| if (attr->private) |
| dev = attr->private; |
| else |
| dev = kobj_to_dev(kobj); |
| nvmem = to_nvmem_device(dev); |
| |
| /* Stop the user from reading */ |
| if (pos >= nvmem->size) |
| return 0; |
| |
| if (!IS_ALIGNED(pos, nvmem->stride)) |
| return -EINVAL; |
| |
| if (count < nvmem->word_size) |
| return -EINVAL; |
| |
| if (pos + count > nvmem->size) |
| count = nvmem->size - pos; |
| |
| count = round_down(count, nvmem->word_size); |
| |
| if (!nvmem->reg_read) |
| return -EPERM; |
| |
| rc = nvmem_reg_read(nvmem, pos, buf, count); |
| |
| if (rc) |
| return rc; |
| |
| return count; |
| } |
| |
| static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj, |
| struct bin_attribute *attr, char *buf, |
| loff_t pos, size_t count) |
| { |
| struct device *dev; |
| struct nvmem_device *nvmem; |
| int rc; |
| |
| if (attr->private) |
| dev = attr->private; |
| else |
| dev = kobj_to_dev(kobj); |
| nvmem = to_nvmem_device(dev); |
| |
| /* Stop the user from writing */ |
| if (pos >= nvmem->size) |
| return -EFBIG; |
| |
| if (!IS_ALIGNED(pos, nvmem->stride)) |
| return -EINVAL; |
| |
| if (count < nvmem->word_size) |
| return -EINVAL; |
| |
| if (pos + count > nvmem->size) |
| count = nvmem->size - pos; |
| |
| count = round_down(count, nvmem->word_size); |
| |
| if (!nvmem->reg_write) |
| return -EPERM; |
| |
| rc = nvmem_reg_write(nvmem, pos, buf, count); |
| |
| if (rc) |
| return rc; |
| |
| return count; |
| } |
| |
| static umode_t nvmem_bin_attr_get_umode(struct nvmem_device *nvmem) |
| { |
| umode_t mode = 0400; |
| |
| if (!nvmem->root_only) |
| mode |= 0044; |
| |
| if (!nvmem->read_only) |
| mode |= 0200; |
| |
| if (!nvmem->reg_write) |
| mode &= ~0200; |
| |
| if (!nvmem->reg_read) |
| mode &= ~0444; |
| |
| return mode; |
| } |
| |
| static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj, |
| struct bin_attribute *attr, int i) |
| { |
| struct device *dev = kobj_to_dev(kobj); |
| struct nvmem_device *nvmem = to_nvmem_device(dev); |
| |
| return nvmem_bin_attr_get_umode(nvmem); |
| } |
| |
| /* default read/write permissions */ |
| static struct bin_attribute bin_attr_rw_nvmem = { |
| .attr = { |
| .name = "nvmem", |
| .mode = 0644, |
| }, |
| .read = bin_attr_nvmem_read, |
| .write = bin_attr_nvmem_write, |
| }; |
| |
| static struct bin_attribute *nvmem_bin_attributes[] = { |
| &bin_attr_rw_nvmem, |
| NULL, |
| }; |
| |
| static const struct attribute_group nvmem_bin_group = { |
| .bin_attrs = nvmem_bin_attributes, |
| .attrs = nvmem_attrs, |
| .is_bin_visible = nvmem_bin_attr_is_visible, |
| }; |
| |
| static const struct attribute_group *nvmem_dev_groups[] = { |
| &nvmem_bin_group, |
| NULL, |
| }; |
| |
| static struct bin_attribute bin_attr_nvmem_eeprom_compat = { |
| .attr = { |
| .name = "eeprom", |
| }, |
| .read = bin_attr_nvmem_read, |
| .write = bin_attr_nvmem_write, |
| }; |
| |
| /* |
| * nvmem_setup_compat() - Create an additional binary entry in |
| * drivers sys directory, to be backwards compatible with the older |
| * drivers/misc/eeprom drivers. |
| */ |
| static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem, |
| const struct nvmem_config *config) |
| { |
| int rval; |
| |
| if (!config->compat) |
| return 0; |
| |
| if (!config->base_dev) |
| return -EINVAL; |
| |
| if (config->type == NVMEM_TYPE_FRAM) |
| bin_attr_nvmem_eeprom_compat.attr.name = "fram"; |
| |
| nvmem->eeprom = bin_attr_nvmem_eeprom_compat; |
| nvmem->eeprom.attr.mode = nvmem_bin_attr_get_umode(nvmem); |
| nvmem->eeprom.size = nvmem->size; |
| #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| nvmem->eeprom.attr.key = &eeprom_lock_key; |
| #endif |
| nvmem->eeprom.private = &nvmem->dev; |
| nvmem->base_dev = config->base_dev; |
| |
| rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom); |
| if (rval) { |
| dev_err(&nvmem->dev, |
| "Failed to create eeprom binary file %d\n", rval); |
| return rval; |
| } |
| |
| nvmem->flags |= FLAG_COMPAT; |
| |
| return 0; |
| } |
| |
| static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem, |
| const struct nvmem_config *config) |
| { |
| if (config->compat) |
| device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); |
| } |
| |
| #else /* CONFIG_NVMEM_SYSFS */ |
| |
| static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem, |
| const struct nvmem_config *config) |
| { |
| return -ENOSYS; |
| } |
| static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem, |
| const struct nvmem_config *config) |
| { |
| } |
| |
| #endif /* CONFIG_NVMEM_SYSFS */ |
| |
| static void nvmem_release(struct device *dev) |
| { |
| struct nvmem_device *nvmem = to_nvmem_device(dev); |
| |
| ida_free(&nvmem_ida, nvmem->id); |
| gpiod_put(nvmem->wp_gpio); |
| kfree(nvmem); |
| } |
| |
| static const struct device_type nvmem_provider_type = { |
| .release = nvmem_release, |
| }; |
| |
| static struct bus_type nvmem_bus_type = { |
| .name = "nvmem", |
| }; |
| |
| static void nvmem_cell_entry_drop(struct nvmem_cell_entry *cell) |
| { |
| blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_REMOVE, cell); |
| mutex_lock(&nvmem_mutex); |
| list_del(&cell->node); |
| mutex_unlock(&nvmem_mutex); |
| of_node_put(cell->np); |
| kfree_const(cell->name); |
| kfree(cell); |
| } |
| |
| static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem) |
| { |
| struct nvmem_cell_entry *cell, *p; |
| |
| list_for_each_entry_safe(cell, p, &nvmem->cells, node) |
| nvmem_cell_entry_drop(cell); |
| } |
| |
| static void nvmem_cell_entry_add(struct nvmem_cell_entry *cell) |
| { |
| mutex_lock(&nvmem_mutex); |
| list_add_tail(&cell->node, &cell->nvmem->cells); |
| mutex_unlock(&nvmem_mutex); |
| blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_ADD, cell); |
| } |
| |
| static int nvmem_cell_info_to_nvmem_cell_entry_nodup(struct nvmem_device *nvmem, |
| const struct nvmem_cell_info *info, |
| struct nvmem_cell_entry *cell) |
| { |
| cell->nvmem = nvmem; |
| cell->offset = info->offset; |
| cell->bytes = info->bytes; |
| cell->name = info->name; |
| |
| cell->bit_offset = info->bit_offset; |
| cell->nbits = info->nbits; |
| |
| if (cell->nbits) |
| cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset, |
| BITS_PER_BYTE); |
| |
| if (!IS_ALIGNED(cell->offset, nvmem->stride)) { |
| dev_err(&nvmem->dev, |
| "cell %s unaligned to nvmem stride %d\n", |
| cell->name ?: "<unknown>", nvmem->stride); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int nvmem_cell_info_to_nvmem_cell_entry(struct nvmem_device *nvmem, |
| const struct nvmem_cell_info *info, |
| struct nvmem_cell_entry *cell) |
| { |
| int err; |
| |
| err = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, cell); |
| if (err) |
| return err; |
| |
| cell->name = kstrdup_const(info->name, GFP_KERNEL); |
| if (!cell->name) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| /** |
| * nvmem_add_cells() - Add cell information to an nvmem device |
| * |
| * @nvmem: nvmem device to add cells to. |
| * @info: nvmem cell info to add to the device |
| * @ncells: number of cells in info |
| * |
| * Return: 0 or negative error code on failure. |
| */ |
| static int nvmem_add_cells(struct nvmem_device *nvmem, |
| const struct nvmem_cell_info *info, |
| int ncells) |
| { |
| struct nvmem_cell_entry **cells; |
| int i, rval; |
| |
| cells = kcalloc(ncells, sizeof(*cells), GFP_KERNEL); |
| if (!cells) |
| return -ENOMEM; |
| |
| for (i = 0; i < ncells; i++) { |
| cells[i] = kzalloc(sizeof(**cells), GFP_KERNEL); |
| if (!cells[i]) { |
| rval = -ENOMEM; |
| goto err; |
| } |
| |
| rval = nvmem_cell_info_to_nvmem_cell_entry(nvmem, &info[i], cells[i]); |
| if (rval) { |
| kfree(cells[i]); |
| goto err; |
| } |
| |
| nvmem_cell_entry_add(cells[i]); |
| } |
| |
| /* remove tmp array */ |
| kfree(cells); |
| |
| return 0; |
| err: |
| while (i--) |
| nvmem_cell_entry_drop(cells[i]); |
| |
| kfree(cells); |
| |
| return rval; |
| } |
| |
| /** |
| * nvmem_register_notifier() - Register a notifier block for nvmem events. |
| * |
| * @nb: notifier block to be called on nvmem events. |
| * |
| * Return: 0 on success, negative error number on failure. |
| */ |
| int nvmem_register_notifier(struct notifier_block *nb) |
| { |
| return blocking_notifier_chain_register(&nvmem_notifier, nb); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_register_notifier); |
| |
| /** |
| * nvmem_unregister_notifier() - Unregister a notifier block for nvmem events. |
| * |
| * @nb: notifier block to be unregistered. |
| * |
| * Return: 0 on success, negative error number on failure. |
| */ |
| int nvmem_unregister_notifier(struct notifier_block *nb) |
| { |
| return blocking_notifier_chain_unregister(&nvmem_notifier, nb); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_unregister_notifier); |
| |
| static int nvmem_add_cells_from_table(struct nvmem_device *nvmem) |
| { |
| const struct nvmem_cell_info *info; |
| struct nvmem_cell_table *table; |
| struct nvmem_cell_entry *cell; |
| int rval = 0, i; |
| |
| mutex_lock(&nvmem_cell_mutex); |
| list_for_each_entry(table, &nvmem_cell_tables, node) { |
| if (strcmp(nvmem_dev_name(nvmem), table->nvmem_name) == 0) { |
| for (i = 0; i < table->ncells; i++) { |
| info = &table->cells[i]; |
| |
| cell = kzalloc(sizeof(*cell), GFP_KERNEL); |
| if (!cell) { |
| rval = -ENOMEM; |
| goto out; |
| } |
| |
| rval = nvmem_cell_info_to_nvmem_cell_entry(nvmem, info, cell); |
| if (rval) { |
| kfree(cell); |
| goto out; |
| } |
| |
| nvmem_cell_entry_add(cell); |
| } |
| } |
| } |
| |
| out: |
| mutex_unlock(&nvmem_cell_mutex); |
| return rval; |
| } |
| |
| static struct nvmem_cell_entry * |
| nvmem_find_cell_entry_by_name(struct nvmem_device *nvmem, const char *cell_id) |
| { |
| struct nvmem_cell_entry *iter, *cell = NULL; |
| |
| mutex_lock(&nvmem_mutex); |
| list_for_each_entry(iter, &nvmem->cells, node) { |
| if (strcmp(cell_id, iter->name) == 0) { |
| cell = iter; |
| break; |
| } |
| } |
| mutex_unlock(&nvmem_mutex); |
| |
| return cell; |
| } |
| |
| static int nvmem_validate_keepouts(struct nvmem_device *nvmem) |
| { |
| unsigned int cur = 0; |
| const struct nvmem_keepout *keepout = nvmem->keepout; |
| const struct nvmem_keepout *keepoutend = keepout + nvmem->nkeepout; |
| |
| while (keepout < keepoutend) { |
| /* Ensure keepouts are sorted and don't overlap. */ |
| if (keepout->start < cur) { |
| dev_err(&nvmem->dev, |
| "Keepout regions aren't sorted or overlap.\n"); |
| |
| return -ERANGE; |
| } |
| |
| if (keepout->end < keepout->start) { |
| dev_err(&nvmem->dev, |
| "Invalid keepout region.\n"); |
| |
| return -EINVAL; |
| } |
| |
| /* |
| * Validate keepouts (and holes between) don't violate |
| * word_size constraints. |
| */ |
| if ((keepout->end - keepout->start < nvmem->word_size) || |
| ((keepout->start != cur) && |
| (keepout->start - cur < nvmem->word_size))) { |
| |
| dev_err(&nvmem->dev, |
| "Keepout regions violate word_size constraints.\n"); |
| |
| return -ERANGE; |
| } |
| |
| /* Validate keepouts don't violate stride (alignment). */ |
| if (!IS_ALIGNED(keepout->start, nvmem->stride) || |
| !IS_ALIGNED(keepout->end, nvmem->stride)) { |
| |
| dev_err(&nvmem->dev, |
| "Keepout regions violate stride.\n"); |
| |
| return -EINVAL; |
| } |
| |
| cur = keepout->end; |
| keepout++; |
| } |
| |
| return 0; |
| } |
| |
| static int nvmem_add_cells_from_of(struct nvmem_device *nvmem) |
| { |
| struct device_node *parent, *child; |
| struct device *dev = &nvmem->dev; |
| struct nvmem_cell_entry *cell; |
| const __be32 *addr; |
| int len; |
| |
| parent = dev->of_node; |
| |
| for_each_child_of_node(parent, child) { |
| addr = of_get_property(child, "reg", &len); |
| if (!addr) |
| continue; |
| if (len < 2 * sizeof(u32)) { |
| dev_err(dev, "nvmem: invalid reg on %pOF\n", child); |
| of_node_put(child); |
| return -EINVAL; |
| } |
| |
| cell = kzalloc(sizeof(*cell), GFP_KERNEL); |
| if (!cell) { |
| of_node_put(child); |
| return -ENOMEM; |
| } |
| |
| cell->nvmem = nvmem; |
| cell->offset = be32_to_cpup(addr++); |
| cell->bytes = be32_to_cpup(addr); |
| cell->name = kasprintf(GFP_KERNEL, "%pOFn", child); |
| |
| addr = of_get_property(child, "bits", &len); |
| if (addr && len == (2 * sizeof(u32))) { |
| cell->bit_offset = be32_to_cpup(addr++); |
| cell->nbits = be32_to_cpup(addr); |
| } |
| |
| if (cell->nbits) |
| cell->bytes = DIV_ROUND_UP( |
| cell->nbits + cell->bit_offset, |
| BITS_PER_BYTE); |
| |
| if (!IS_ALIGNED(cell->offset, nvmem->stride)) { |
| dev_err(dev, "cell %s unaligned to nvmem stride %d\n", |
| cell->name, nvmem->stride); |
| /* Cells already added will be freed later. */ |
| kfree_const(cell->name); |
| kfree(cell); |
| of_node_put(child); |
| return -EINVAL; |
| } |
| |
| cell->np = of_node_get(child); |
| nvmem_cell_entry_add(cell); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * nvmem_register() - Register a nvmem device for given nvmem_config. |
| * Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem |
| * |
| * @config: nvmem device configuration with which nvmem device is created. |
| * |
| * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device |
| * on success. |
| */ |
| |
| struct nvmem_device *nvmem_register(const struct nvmem_config *config) |
| { |
| struct nvmem_device *nvmem; |
| int rval; |
| |
| if (!config->dev) |
| return ERR_PTR(-EINVAL); |
| |
| if (!config->reg_read && !config->reg_write) |
| return ERR_PTR(-EINVAL); |
| |
| nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL); |
| if (!nvmem) |
| return ERR_PTR(-ENOMEM); |
| |
| rval = ida_alloc(&nvmem_ida, GFP_KERNEL); |
| if (rval < 0) { |
| kfree(nvmem); |
| return ERR_PTR(rval); |
| } |
| |
| if (config->wp_gpio) |
| nvmem->wp_gpio = config->wp_gpio; |
| else |
| nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp", |
| GPIOD_OUT_HIGH); |
| if (IS_ERR(nvmem->wp_gpio)) { |
| ida_free(&nvmem_ida, nvmem->id); |
| rval = PTR_ERR(nvmem->wp_gpio); |
| kfree(nvmem); |
| return ERR_PTR(rval); |
| } |
| |
| kref_init(&nvmem->refcnt); |
| INIT_LIST_HEAD(&nvmem->cells); |
| |
| nvmem->id = rval; |
| nvmem->owner = config->owner; |
| if (!nvmem->owner && config->dev->driver) |
| nvmem->owner = config->dev->driver->owner; |
| nvmem->stride = config->stride ?: 1; |
| nvmem->word_size = config->word_size ?: 1; |
| nvmem->size = config->size; |
| nvmem->dev.type = &nvmem_provider_type; |
| nvmem->dev.bus = &nvmem_bus_type; |
| nvmem->dev.parent = config->dev; |
| nvmem->root_only = config->root_only; |
| nvmem->priv = config->priv; |
| nvmem->type = config->type; |
| nvmem->reg_read = config->reg_read; |
| nvmem->reg_write = config->reg_write; |
| nvmem->cell_post_process = config->cell_post_process; |
| nvmem->keepout = config->keepout; |
| nvmem->nkeepout = config->nkeepout; |
| if (config->of_node) |
| nvmem->dev.of_node = config->of_node; |
| else if (!config->no_of_node) |
| nvmem->dev.of_node = config->dev->of_node; |
| |
| switch (config->id) { |
| case NVMEM_DEVID_NONE: |
| dev_set_name(&nvmem->dev, "%s", config->name); |
| break; |
| case NVMEM_DEVID_AUTO: |
| dev_set_name(&nvmem->dev, "%s%d", config->name, nvmem->id); |
| break; |
| default: |
| dev_set_name(&nvmem->dev, "%s%d", |
| config->name ? : "nvmem", |
| config->name ? config->id : nvmem->id); |
| break; |
| } |
| |
| nvmem->read_only = device_property_present(config->dev, "read-only") || |
| config->read_only || !nvmem->reg_write; |
| |
| #ifdef CONFIG_NVMEM_SYSFS |
| nvmem->dev.groups = nvmem_dev_groups; |
| #endif |
| |
| if (nvmem->nkeepout) { |
| rval = nvmem_validate_keepouts(nvmem); |
| if (rval) { |
| ida_free(&nvmem_ida, nvmem->id); |
| kfree(nvmem); |
| return ERR_PTR(rval); |
| } |
| } |
| |
| dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); |
| |
| rval = device_register(&nvmem->dev); |
| if (rval) |
| goto err_put_device; |
| |
| if (config->compat) { |
| rval = nvmem_sysfs_setup_compat(nvmem, config); |
| if (rval) |
| goto err_device_del; |
| } |
| |
| if (config->cells) { |
| rval = nvmem_add_cells(nvmem, config->cells, config->ncells); |
| if (rval) |
| goto err_teardown_compat; |
| } |
| |
| rval = nvmem_add_cells_from_table(nvmem); |
| if (rval) |
| goto err_remove_cells; |
| |
| rval = nvmem_add_cells_from_of(nvmem); |
| if (rval) |
| goto err_remove_cells; |
| |
| blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem); |
| |
| return nvmem; |
| |
| err_remove_cells: |
| nvmem_device_remove_all_cells(nvmem); |
| err_teardown_compat: |
| if (config->compat) |
| nvmem_sysfs_remove_compat(nvmem, config); |
| err_device_del: |
| device_del(&nvmem->dev); |
| err_put_device: |
| put_device(&nvmem->dev); |
| |
| return ERR_PTR(rval); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_register); |
| |
| static void nvmem_device_release(struct kref *kref) |
| { |
| struct nvmem_device *nvmem; |
| |
| nvmem = container_of(kref, struct nvmem_device, refcnt); |
| |
| blocking_notifier_call_chain(&nvmem_notifier, NVMEM_REMOVE, nvmem); |
| |
| if (nvmem->flags & FLAG_COMPAT) |
| device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); |
| |
| nvmem_device_remove_all_cells(nvmem); |
| device_unregister(&nvmem->dev); |
| } |
| |
| /** |
| * nvmem_unregister() - Unregister previously registered nvmem device |
| * |
| * @nvmem: Pointer to previously registered nvmem device. |
| */ |
| void nvmem_unregister(struct nvmem_device *nvmem) |
| { |
| kref_put(&nvmem->refcnt, nvmem_device_release); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_unregister); |
| |
| static void devm_nvmem_release(struct device *dev, void *res) |
| { |
| nvmem_unregister(*(struct nvmem_device **)res); |
| } |
| |
| /** |
| * devm_nvmem_register() - Register a managed nvmem device for given |
| * nvmem_config. |
| * Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem |
| * |
| * @dev: Device that uses the nvmem device. |
| * @config: nvmem device configuration with which nvmem device is created. |
| * |
| * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device |
| * on success. |
| */ |
| struct nvmem_device *devm_nvmem_register(struct device *dev, |
| const struct nvmem_config *config) |
| { |
| struct nvmem_device **ptr, *nvmem; |
| |
| ptr = devres_alloc(devm_nvmem_release, sizeof(*ptr), GFP_KERNEL); |
| if (!ptr) |
| return ERR_PTR(-ENOMEM); |
| |
| nvmem = nvmem_register(config); |
| |
| if (!IS_ERR(nvmem)) { |
| *ptr = nvmem; |
| devres_add(dev, ptr); |
| } else { |
| devres_free(ptr); |
| } |
| |
| return nvmem; |
| } |
| EXPORT_SYMBOL_GPL(devm_nvmem_register); |
| |
| static int devm_nvmem_match(struct device *dev, void *res, void *data) |
| { |
| struct nvmem_device **r = res; |
| |
| return *r == data; |
| } |
| |
| /** |
| * devm_nvmem_unregister() - Unregister previously registered managed nvmem |
| * device. |
| * |
| * @dev: Device that uses the nvmem device. |
| * @nvmem: Pointer to previously registered nvmem device. |
| * |
| * Return: Will be negative on error or zero on success. |
| */ |
| int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem) |
| { |
| return devres_release(dev, devm_nvmem_release, devm_nvmem_match, nvmem); |
| } |
| EXPORT_SYMBOL(devm_nvmem_unregister); |
| |
| static struct nvmem_device *__nvmem_device_get(void *data, |
| int (*match)(struct device *dev, const void *data)) |
| { |
| struct nvmem_device *nvmem = NULL; |
| struct device *dev; |
| |
| mutex_lock(&nvmem_mutex); |
| dev = bus_find_device(&nvmem_bus_type, NULL, data, match); |
| if (dev) |
| nvmem = to_nvmem_device(dev); |
| mutex_unlock(&nvmem_mutex); |
| if (!nvmem) |
| return ERR_PTR(-EPROBE_DEFER); |
| |
| if (!try_module_get(nvmem->owner)) { |
| dev_err(&nvmem->dev, |
| "could not increase module refcount for cell %s\n", |
| nvmem_dev_name(nvmem)); |
| |
| put_device(&nvmem->dev); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| kref_get(&nvmem->refcnt); |
| |
| return nvmem; |
| } |
| |
| static void __nvmem_device_put(struct nvmem_device *nvmem) |
| { |
| put_device(&nvmem->dev); |
| module_put(nvmem->owner); |
| kref_put(&nvmem->refcnt, nvmem_device_release); |
| } |
| |
| #if IS_ENABLED(CONFIG_OF) |
| /** |
| * of_nvmem_device_get() - Get nvmem device from a given id |
| * |
| * @np: Device tree node that uses the nvmem device. |
| * @id: nvmem name from nvmem-names property. |
| * |
| * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device |
| * on success. |
| */ |
| struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id) |
| { |
| |
| struct device_node *nvmem_np; |
| struct nvmem_device *nvmem; |
| int index = 0; |
| |
| if (id) |
| index = of_property_match_string(np, "nvmem-names", id); |
| |
| nvmem_np = of_parse_phandle(np, "nvmem", index); |
| if (!nvmem_np) |
| return ERR_PTR(-ENOENT); |
| |
| nvmem = __nvmem_device_get(nvmem_np, device_match_of_node); |
| of_node_put(nvmem_np); |
| return nvmem; |
| } |
| EXPORT_SYMBOL_GPL(of_nvmem_device_get); |
| #endif |
| |
| /** |
| * nvmem_device_get() - Get nvmem device from a given id |
| * |
| * @dev: Device that uses the nvmem device. |
| * @dev_name: name of the requested nvmem device. |
| * |
| * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device |
| * on success. |
| */ |
| struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name) |
| { |
| if (dev->of_node) { /* try dt first */ |
| struct nvmem_device *nvmem; |
| |
| nvmem = of_nvmem_device_get(dev->of_node, dev_name); |
| |
| if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER) |
| return nvmem; |
| |
| } |
| |
| return __nvmem_device_get((void *)dev_name, device_match_name); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_get); |
| |
| /** |
| * nvmem_device_find() - Find nvmem device with matching function |
| * |
| * @data: Data to pass to match function |
| * @match: Callback function to check device |
| * |
| * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device |
| * on success. |
| */ |
| struct nvmem_device *nvmem_device_find(void *data, |
| int (*match)(struct device *dev, const void *data)) |
| { |
| return __nvmem_device_get(data, match); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_find); |
| |
| static int devm_nvmem_device_match(struct device *dev, void *res, void *data) |
| { |
| struct nvmem_device **nvmem = res; |
| |
| if (WARN_ON(!nvmem || !*nvmem)) |
| return 0; |
| |
| return *nvmem == data; |
| } |
| |
| static void devm_nvmem_device_release(struct device *dev, void *res) |
| { |
| nvmem_device_put(*(struct nvmem_device **)res); |
| } |
| |
| /** |
| * devm_nvmem_device_put() - put alredy got nvmem device |
| * |
| * @dev: Device that uses the nvmem device. |
| * @nvmem: pointer to nvmem device allocated by devm_nvmem_cell_get(), |
| * that needs to be released. |
| */ |
| void devm_nvmem_device_put(struct device *dev, struct nvmem_device *nvmem) |
| { |
| int ret; |
| |
| ret = devres_release(dev, devm_nvmem_device_release, |
| devm_nvmem_device_match, nvmem); |
| |
| WARN_ON(ret); |
| } |
| EXPORT_SYMBOL_GPL(devm_nvmem_device_put); |
| |
| /** |
| * nvmem_device_put() - put alredy got nvmem device |
| * |
| * @nvmem: pointer to nvmem device that needs to be released. |
| */ |
| void nvmem_device_put(struct nvmem_device *nvmem) |
| { |
| __nvmem_device_put(nvmem); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_put); |
| |
| /** |
| * devm_nvmem_device_get() - Get nvmem cell of device form a given id |
| * |
| * @dev: Device that requests the nvmem device. |
| * @id: name id for the requested nvmem device. |
| * |
| * Return: ERR_PTR() on error or a valid pointer to a struct nvmem_cell |
| * on success. The nvmem_cell will be freed by the automatically once the |
| * device is freed. |
| */ |
| struct nvmem_device *devm_nvmem_device_get(struct device *dev, const char *id) |
| { |
| struct nvmem_device **ptr, *nvmem; |
| |
| ptr = devres_alloc(devm_nvmem_device_release, sizeof(*ptr), GFP_KERNEL); |
| if (!ptr) |
| return ERR_PTR(-ENOMEM); |
| |
| nvmem = nvmem_device_get(dev, id); |
| if (!IS_ERR(nvmem)) { |
| *ptr = nvmem; |
| devres_add(dev, ptr); |
| } else { |
| devres_free(ptr); |
| } |
| |
| return nvmem; |
| } |
| EXPORT_SYMBOL_GPL(devm_nvmem_device_get); |
| |
| static struct nvmem_cell *nvmem_create_cell(struct nvmem_cell_entry *entry, const char *id) |
| { |
| struct nvmem_cell *cell; |
| const char *name = NULL; |
| |
| cell = kzalloc(sizeof(*cell), GFP_KERNEL); |
| if (!cell) |
| return ERR_PTR(-ENOMEM); |
| |
| if (id) { |
| name = kstrdup_const(id, GFP_KERNEL); |
| if (!name) { |
| kfree(cell); |
| return ERR_PTR(-ENOMEM); |
| } |
| } |
| |
| cell->id = name; |
| cell->entry = entry; |
| |
| return cell; |
| } |
| |
| static struct nvmem_cell * |
| nvmem_cell_get_from_lookup(struct device *dev, const char *con_id) |
| { |
| struct nvmem_cell_entry *cell_entry; |
| struct nvmem_cell *cell = ERR_PTR(-ENOENT); |
| struct nvmem_cell_lookup *lookup; |
| struct nvmem_device *nvmem; |
| const char *dev_id; |
| |
| if (!dev) |
| return ERR_PTR(-EINVAL); |
| |
| dev_id = dev_name(dev); |
| |
| mutex_lock(&nvmem_lookup_mutex); |
| |
| list_for_each_entry(lookup, &nvmem_lookup_list, node) { |
| if ((strcmp(lookup->dev_id, dev_id) == 0) && |
| (strcmp(lookup->con_id, con_id) == 0)) { |
| /* This is the right entry. */ |
| nvmem = __nvmem_device_get((void *)lookup->nvmem_name, |
| device_match_name); |
| if (IS_ERR(nvmem)) { |
| /* Provider may not be registered yet. */ |
| cell = ERR_CAST(nvmem); |
| break; |
| } |
| |
| cell_entry = nvmem_find_cell_entry_by_name(nvmem, |
| lookup->cell_name); |
| if (!cell_entry) { |
| __nvmem_device_put(nvmem); |
| cell = ERR_PTR(-ENOENT); |
| } else { |
| cell = nvmem_create_cell(cell_entry, con_id); |
| if (IS_ERR(cell)) |
| __nvmem_device_put(nvmem); |
| } |
| break; |
| } |
| } |
| |
| mutex_unlock(&nvmem_lookup_mutex); |
| return cell; |
| } |
| |
| #if IS_ENABLED(CONFIG_OF) |
| static struct nvmem_cell_entry * |
| nvmem_find_cell_entry_by_node(struct nvmem_device *nvmem, struct device_node *np) |
| { |
| struct nvmem_cell_entry *iter, *cell = NULL; |
| |
| mutex_lock(&nvmem_mutex); |
| list_for_each_entry(iter, &nvmem->cells, node) { |
| if (np == iter->np) { |
| cell = iter; |
| break; |
| } |
| } |
| mutex_unlock(&nvmem_mutex); |
| |
| return cell; |
| } |
| |
| /** |
| * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id |
| * |
| * @np: Device tree node that uses the nvmem cell. |
| * @id: nvmem cell name from nvmem-cell-names property, or NULL |
| * for the cell at index 0 (the lone cell with no accompanying |
| * nvmem-cell-names property). |
| * |
| * Return: Will be an ERR_PTR() on error or a valid pointer |
| * to a struct nvmem_cell. The nvmem_cell will be freed by the |
| * nvmem_cell_put(). |
| */ |
| struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id) |
| { |
| struct device_node *cell_np, *nvmem_np; |
| struct nvmem_device *nvmem; |
| struct nvmem_cell_entry *cell_entry; |
| struct nvmem_cell *cell; |
| int index = 0; |
| |
| /* if cell name exists, find index to the name */ |
| if (id) |
| index = of_property_match_string(np, "nvmem-cell-names", id); |
| |
| cell_np = of_parse_phandle(np, "nvmem-cells", index); |
| if (!cell_np) |
| return ERR_PTR(-ENOENT); |
| |
| nvmem_np = of_get_next_parent(cell_np); |
| if (!nvmem_np) |
| return ERR_PTR(-EINVAL); |
| |
| nvmem = __nvmem_device_get(nvmem_np, device_match_of_node); |
| of_node_put(nvmem_np); |
| if (IS_ERR(nvmem)) |
| return ERR_CAST(nvmem); |
| |
| cell_entry = nvmem_find_cell_entry_by_node(nvmem, cell_np); |
| if (!cell_entry) { |
| __nvmem_device_put(nvmem); |
| return ERR_PTR(-ENOENT); |
| } |
| |
| cell = nvmem_create_cell(cell_entry, id); |
| if (IS_ERR(cell)) |
| __nvmem_device_put(nvmem); |
| |
| return cell; |
| } |
| EXPORT_SYMBOL_GPL(of_nvmem_cell_get); |
| #endif |
| |
| /** |
| * nvmem_cell_get() - Get nvmem cell of device form a given cell name |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @id: nvmem cell name to get (this corresponds with the name from the |
| * nvmem-cell-names property for DT systems and with the con_id from |
| * the lookup entry for non-DT systems). |
| * |
| * Return: Will be an ERR_PTR() on error or a valid pointer |
| * to a struct nvmem_cell. The nvmem_cell will be freed by the |
| * nvmem_cell_put(). |
| */ |
| struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *id) |
| { |
| struct nvmem_cell *cell; |
| |
| if (dev->of_node) { /* try dt first */ |
| cell = of_nvmem_cell_get(dev->of_node, id); |
| if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER) |
| return cell; |
| } |
| |
| /* NULL cell id only allowed for device tree; invalid otherwise */ |
| if (!id) |
| return ERR_PTR(-EINVAL); |
| |
| return nvmem_cell_get_from_lookup(dev, id); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_get); |
| |
| static void devm_nvmem_cell_release(struct device *dev, void *res) |
| { |
| nvmem_cell_put(*(struct nvmem_cell **)res); |
| } |
| |
| /** |
| * devm_nvmem_cell_get() - Get nvmem cell of device form a given id |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @id: nvmem cell name id to get. |
| * |
| * Return: Will be an ERR_PTR() on error or a valid pointer |
| * to a struct nvmem_cell. The nvmem_cell will be freed by the |
| * automatically once the device is freed. |
| */ |
| struct nvmem_cell *devm_nvmem_cell_get(struct device *dev, const char *id) |
| { |
| struct nvmem_cell **ptr, *cell; |
| |
| ptr = devres_alloc(devm_nvmem_cell_release, sizeof(*ptr), GFP_KERNEL); |
| if (!ptr) |
| return ERR_PTR(-ENOMEM); |
| |
| cell = nvmem_cell_get(dev, id); |
| if (!IS_ERR(cell)) { |
| *ptr = cell; |
| devres_add(dev, ptr); |
| } else { |
| devres_free(ptr); |
| } |
| |
| return cell; |
| } |
| EXPORT_SYMBOL_GPL(devm_nvmem_cell_get); |
| |
| static int devm_nvmem_cell_match(struct device *dev, void *res, void *data) |
| { |
| struct nvmem_cell **c = res; |
| |
| if (WARN_ON(!c || !*c)) |
| return 0; |
| |
| return *c == data; |
| } |
| |
| /** |
| * devm_nvmem_cell_put() - Release previously allocated nvmem cell |
| * from devm_nvmem_cell_get. |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @cell: Previously allocated nvmem cell by devm_nvmem_cell_get(). |
| */ |
| void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell) |
| { |
| int ret; |
| |
| ret = devres_release(dev, devm_nvmem_cell_release, |
| devm_nvmem_cell_match, cell); |
| |
| WARN_ON(ret); |
| } |
| EXPORT_SYMBOL(devm_nvmem_cell_put); |
| |
| /** |
| * nvmem_cell_put() - Release previously allocated nvmem cell. |
| * |
| * @cell: Previously allocated nvmem cell by nvmem_cell_get(). |
| */ |
| void nvmem_cell_put(struct nvmem_cell *cell) |
| { |
| struct nvmem_device *nvmem = cell->entry->nvmem; |
| |
| if (cell->id) |
| kfree_const(cell->id); |
| |
| kfree(cell); |
| __nvmem_device_put(nvmem); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_put); |
| |
| static void nvmem_shift_read_buffer_in_place(struct nvmem_cell_entry *cell, void *buf) |
| { |
| u8 *p, *b; |
| int i, extra, bit_offset = cell->bit_offset; |
| |
| p = b = buf; |
| if (bit_offset) { |
| /* First shift */ |
| *b++ >>= bit_offset; |
| |
| /* setup rest of the bytes if any */ |
| for (i = 1; i < cell->bytes; i++) { |
| /* Get bits from next byte and shift them towards msb */ |
| *p |= *b << (BITS_PER_BYTE - bit_offset); |
| |
| p = b; |
| *b++ >>= bit_offset; |
| } |
| } else { |
| /* point to the msb */ |
| p += cell->bytes - 1; |
| } |
| |
| /* result fits in less bytes */ |
| extra = cell->bytes - DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE); |
| while (--extra >= 0) |
| *p-- = 0; |
| |
| /* clear msb bits if any leftover in the last byte */ |
| if (cell->nbits % BITS_PER_BYTE) |
| *p &= GENMASK((cell->nbits % BITS_PER_BYTE) - 1, 0); |
| } |
| |
| static int __nvmem_cell_read(struct nvmem_device *nvmem, |
| struct nvmem_cell_entry *cell, |
| void *buf, size_t *len, const char *id) |
| { |
| int rc; |
| |
| rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes); |
| |
| if (rc) |
| return rc; |
| |
| /* shift bits in-place */ |
| if (cell->bit_offset || cell->nbits) |
| nvmem_shift_read_buffer_in_place(cell, buf); |
| |
| if (nvmem->cell_post_process) { |
| rc = nvmem->cell_post_process(nvmem->priv, id, |
| cell->offset, buf, cell->bytes); |
| if (rc) |
| return rc; |
| } |
| |
| if (len) |
| *len = cell->bytes; |
| |
| return 0; |
| } |
| |
| /** |
| * nvmem_cell_read() - Read a given nvmem cell |
| * |
| * @cell: nvmem cell to be read. |
| * @len: pointer to length of cell which will be populated on successful read; |
| * can be NULL. |
| * |
| * Return: ERR_PTR() on error or a valid pointer to a buffer on success. The |
| * buffer should be freed by the consumer with a kfree(). |
| */ |
| void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len) |
| { |
| struct nvmem_device *nvmem = cell->entry->nvmem; |
| u8 *buf; |
| int rc; |
| |
| if (!nvmem) |
| return ERR_PTR(-EINVAL); |
| |
| buf = kzalloc(cell->entry->bytes, GFP_KERNEL); |
| if (!buf) |
| return ERR_PTR(-ENOMEM); |
| |
| rc = __nvmem_cell_read(nvmem, cell->entry, buf, len, cell->id); |
| if (rc) { |
| kfree(buf); |
| return ERR_PTR(rc); |
| } |
| |
| return buf; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_read); |
| |
| static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell_entry *cell, |
| u8 *_buf, int len) |
| { |
| struct nvmem_device *nvmem = cell->nvmem; |
| int i, rc, nbits, bit_offset = cell->bit_offset; |
| u8 v, *p, *buf, *b, pbyte, pbits; |
| |
| nbits = cell->nbits; |
| buf = kzalloc(cell->bytes, GFP_KERNEL); |
| if (!buf) |
| return ERR_PTR(-ENOMEM); |
| |
| memcpy(buf, _buf, len); |
| p = b = buf; |
| |
| if (bit_offset) { |
| pbyte = *b; |
| *b <<= bit_offset; |
| |
| /* setup the first byte with lsb bits from nvmem */ |
| rc = nvmem_reg_read(nvmem, cell->offset, &v, 1); |
| if (rc) |
| goto err; |
| *b++ |= GENMASK(bit_offset - 1, 0) & v; |
| |
| /* setup rest of the byte if any */ |
| for (i = 1; i < cell->bytes; i++) { |
| /* Get last byte bits and shift them towards lsb */ |
| pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset); |
| pbyte = *b; |
| p = b; |
| *b <<= bit_offset; |
| *b++ |= pbits; |
| } |
| } |
| |
| /* if it's not end on byte boundary */ |
| if ((nbits + bit_offset) % BITS_PER_BYTE) { |
| /* setup the last byte with msb bits from nvmem */ |
| rc = nvmem_reg_read(nvmem, |
| cell->offset + cell->bytes - 1, &v, 1); |
| if (rc) |
| goto err; |
| *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v; |
| |
| } |
| |
| return buf; |
| err: |
| kfree(buf); |
| return ERR_PTR(rc); |
| } |
| |
| static int __nvmem_cell_entry_write(struct nvmem_cell_entry *cell, void *buf, size_t len) |
| { |
| struct nvmem_device *nvmem = cell->nvmem; |
| int rc; |
| |
| if (!nvmem || nvmem->read_only || |
| (cell->bit_offset == 0 && len != cell->bytes)) |
| return -EINVAL; |
| |
| if (cell->bit_offset || cell->nbits) { |
| buf = nvmem_cell_prepare_write_buffer(cell, buf, len); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| } |
| |
| rc = nvmem_reg_write(nvmem, cell->offset, buf, cell->bytes); |
| |
| /* free the tmp buffer */ |
| if (cell->bit_offset || cell->nbits) |
| kfree(buf); |
| |
| if (rc) |
| return rc; |
| |
| return len; |
| } |
| |
| /** |
| * nvmem_cell_write() - Write to a given nvmem cell |
| * |
| * @cell: nvmem cell to be written. |
| * @buf: Buffer to be written. |
| * @len: length of buffer to be written to nvmem cell. |
| * |
| * Return: length of bytes written or negative on failure. |
| */ |
| int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) |
| { |
| return __nvmem_cell_entry_write(cell->entry, buf, len); |
| } |
| |
| EXPORT_SYMBOL_GPL(nvmem_cell_write); |
| |
| static int nvmem_cell_read_common(struct device *dev, const char *cell_id, |
| void *val, size_t count) |
| { |
| struct nvmem_cell *cell; |
| void *buf; |
| size_t len; |
| |
| cell = nvmem_cell_get(dev, cell_id); |
| if (IS_ERR(cell)) |
| return PTR_ERR(cell); |
| |
| buf = nvmem_cell_read(cell, &len); |
| if (IS_ERR(buf)) { |
| nvmem_cell_put(cell); |
| return PTR_ERR(buf); |
| } |
| if (len != count) { |
| kfree(buf); |
| nvmem_cell_put(cell); |
| return -EINVAL; |
| } |
| memcpy(val, buf, count); |
| kfree(buf); |
| nvmem_cell_put(cell); |
| |
| return 0; |
| } |
| |
| /** |
| * nvmem_cell_read_u8() - Read a cell value as a u8 |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @cell_id: Name of nvmem cell to read. |
| * @val: pointer to output value. |
| * |
| * Return: 0 on success or negative errno. |
| */ |
| int nvmem_cell_read_u8(struct device *dev, const char *cell_id, u8 *val) |
| { |
| return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val)); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_read_u8); |
| |
| /** |
| * nvmem_cell_read_u16() - Read a cell value as a u16 |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @cell_id: Name of nvmem cell to read. |
| * @val: pointer to output value. |
| * |
| * Return: 0 on success or negative errno. |
| */ |
| int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val) |
| { |
| return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val)); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_read_u16); |
| |
| /** |
| * nvmem_cell_read_u32() - Read a cell value as a u32 |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @cell_id: Name of nvmem cell to read. |
| * @val: pointer to output value. |
| * |
| * Return: 0 on success or negative errno. |
| */ |
| int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val) |
| { |
| return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val)); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_read_u32); |
| |
| /** |
| * nvmem_cell_read_u64() - Read a cell value as a u64 |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @cell_id: Name of nvmem cell to read. |
| * @val: pointer to output value. |
| * |
| * Return: 0 on success or negative errno. |
| */ |
| int nvmem_cell_read_u64(struct device *dev, const char *cell_id, u64 *val) |
| { |
| return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val)); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_read_u64); |
| |
| static const void *nvmem_cell_read_variable_common(struct device *dev, |
| const char *cell_id, |
| size_t max_len, size_t *len) |
| { |
| struct nvmem_cell *cell; |
| int nbits; |
| void *buf; |
| |
| cell = nvmem_cell_get(dev, cell_id); |
| if (IS_ERR(cell)) |
| return cell; |
| |
| nbits = cell->entry->nbits; |
| buf = nvmem_cell_read(cell, len); |
| nvmem_cell_put(cell); |
| if (IS_ERR(buf)) |
| return buf; |
| |
| /* |
| * If nbits is set then nvmem_cell_read() can significantly exaggerate |
| * the length of the real data. Throw away the extra junk. |
| */ |
| if (nbits) |
| *len = DIV_ROUND_UP(nbits, 8); |
| |
| if (*len > max_len) { |
| kfree(buf); |
| return ERR_PTR(-ERANGE); |
| } |
| |
| return buf; |
| } |
| |
| /** |
| * nvmem_cell_read_variable_le_u32() - Read up to 32-bits of data as a little endian number. |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @cell_id: Name of nvmem cell to read. |
| * @val: pointer to output value. |
| * |
| * Return: 0 on success or negative errno. |
| */ |
| int nvmem_cell_read_variable_le_u32(struct device *dev, const char *cell_id, |
| u32 *val) |
| { |
| size_t len; |
| const u8 *buf; |
| int i; |
| |
| buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| |
| /* Copy w/ implicit endian conversion */ |
| *val = 0; |
| for (i = 0; i < len; i++) |
| *val |= buf[i] << (8 * i); |
| |
| kfree(buf); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u32); |
| |
| /** |
| * nvmem_cell_read_variable_le_u64() - Read up to 64-bits of data as a little endian number. |
| * |
| * @dev: Device that requests the nvmem cell. |
| * @cell_id: Name of nvmem cell to read. |
| * @val: pointer to output value. |
| * |
| * Return: 0 on success or negative errno. |
| */ |
| int nvmem_cell_read_variable_le_u64(struct device *dev, const char *cell_id, |
| u64 *val) |
| { |
| size_t len; |
| const u8 *buf; |
| int i; |
| |
| buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| |
| /* Copy w/ implicit endian conversion */ |
| *val = 0; |
| for (i = 0; i < len; i++) |
| *val |= (uint64_t)buf[i] << (8 * i); |
| |
| kfree(buf); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u64); |
| |
| /** |
| * nvmem_device_cell_read() - Read a given nvmem device and cell |
| * |
| * @nvmem: nvmem device to read from. |
| * @info: nvmem cell info to be read. |
| * @buf: buffer pointer which will be populated on successful read. |
| * |
| * Return: length of successful bytes read on success and negative |
| * error code on error. |
| */ |
| ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem, |
| struct nvmem_cell_info *info, void *buf) |
| { |
| struct nvmem_cell_entry cell; |
| int rc; |
| ssize_t len; |
| |
| if (!nvmem) |
| return -EINVAL; |
| |
| rc = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, &cell); |
| if (rc) |
| return rc; |
| |
| rc = __nvmem_cell_read(nvmem, &cell, buf, &len, NULL); |
| if (rc) |
| return rc; |
| |
| return len; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_cell_read); |
| |
| /** |
| * nvmem_device_cell_write() - Write cell to a given nvmem device |
| * |
| * @nvmem: nvmem device to be written to. |
| * @info: nvmem cell info to be written. |
| * @buf: buffer to be written to cell. |
| * |
| * Return: length of bytes written or negative error code on failure. |
| */ |
| int nvmem_device_cell_write(struct nvmem_device *nvmem, |
| struct nvmem_cell_info *info, void *buf) |
| { |
| struct nvmem_cell_entry cell; |
| int rc; |
| |
| if (!nvmem) |
| return -EINVAL; |
| |
| rc = nvmem_cell_info_to_nvmem_cell_entry_nodup(nvmem, info, &cell); |
| if (rc) |
| return rc; |
| |
| return __nvmem_cell_entry_write(&cell, buf, cell.bytes); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_cell_write); |
| |
| /** |
| * nvmem_device_read() - Read from a given nvmem device |
| * |
| * @nvmem: nvmem device to read from. |
| * @offset: offset in nvmem device. |
| * @bytes: number of bytes to read. |
| * @buf: buffer pointer which will be populated on successful read. |
| * |
| * Return: length of successful bytes read on success and negative |
| * error code on error. |
| */ |
| int nvmem_device_read(struct nvmem_device *nvmem, |
| unsigned int offset, |
| size_t bytes, void *buf) |
| { |
| int rc; |
| |
| if (!nvmem) |
| return -EINVAL; |
| |
| rc = nvmem_reg_read(nvmem, offset, buf, bytes); |
| |
| if (rc) |
| return rc; |
| |
| return bytes; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_read); |
| |
| /** |
| * nvmem_device_write() - Write cell to a given nvmem device |
| * |
| * @nvmem: nvmem device to be written to. |
| * @offset: offset in nvmem device. |
| * @bytes: number of bytes to write. |
| * @buf: buffer to be written. |
| * |
| * Return: length of bytes written or negative error code on failure. |
| */ |
| int nvmem_device_write(struct nvmem_device *nvmem, |
| unsigned int offset, |
| size_t bytes, void *buf) |
| { |
| int rc; |
| |
| if (!nvmem) |
| return -EINVAL; |
| |
| rc = nvmem_reg_write(nvmem, offset, buf, bytes); |
| |
| if (rc) |
| return rc; |
| |
| |
| return bytes; |
| } |
| EXPORT_SYMBOL_GPL(nvmem_device_write); |
| |
| /** |
| * nvmem_add_cell_table() - register a table of cell info entries |
| * |
| * @table: table of cell info entries |
| */ |
| void nvmem_add_cell_table(struct nvmem_cell_table *table) |
| { |
| mutex_lock(&nvmem_cell_mutex); |
| list_add_tail(&table->node, &nvmem_cell_tables); |
| mutex_unlock(&nvmem_cell_mutex); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_add_cell_table); |
| |
| /** |
| * nvmem_del_cell_table() - remove a previously registered cell info table |
| * |
| * @table: table of cell info entries |
| */ |
| void nvmem_del_cell_table(struct nvmem_cell_table *table) |
| { |
| mutex_lock(&nvmem_cell_mutex); |
| list_del(&table->node); |
| mutex_unlock(&nvmem_cell_mutex); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_del_cell_table); |
| |
| /** |
| * nvmem_add_cell_lookups() - register a list of cell lookup entries |
| * |
| * @entries: array of cell lookup entries |
| * @nentries: number of cell lookup entries in the array |
| */ |
| void nvmem_add_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries) |
| { |
| int i; |
| |
| mutex_lock(&nvmem_lookup_mutex); |
| for (i = 0; i < nentries; i++) |
| list_add_tail(&entries[i].node, &nvmem_lookup_list); |
| mutex_unlock(&nvmem_lookup_mutex); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_add_cell_lookups); |
| |
| /** |
| * nvmem_del_cell_lookups() - remove a list of previously added cell lookup |
| * entries |
| * |
| * @entries: array of cell lookup entries |
| * @nentries: number of cell lookup entries in the array |
| */ |
| void nvmem_del_cell_lookups(struct nvmem_cell_lookup *entries, size_t nentries) |
| { |
| int i; |
| |
| mutex_lock(&nvmem_lookup_mutex); |
| for (i = 0; i < nentries; i++) |
| list_del(&entries[i].node); |
| mutex_unlock(&nvmem_lookup_mutex); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_del_cell_lookups); |
| |
| /** |
| * nvmem_dev_name() - Get the name of a given nvmem device. |
| * |
| * @nvmem: nvmem device. |
| * |
| * Return: name of the nvmem device. |
| */ |
| const char *nvmem_dev_name(struct nvmem_device *nvmem) |
| { |
| return dev_name(&nvmem->dev); |
| } |
| EXPORT_SYMBOL_GPL(nvmem_dev_name); |
| |
| static int __init nvmem_init(void) |
| { |
| return bus_register(&nvmem_bus_type); |
| } |
| |
| static void __exit nvmem_exit(void) |
| { |
| bus_unregister(&nvmem_bus_type); |
| } |
| |
| subsys_initcall(nvmem_init); |
| module_exit(nvmem_exit); |
| |
| MODULE_AUTHOR("Srinivas Kandagatla <srinivas.kandagatla@linaro.org"); |
| MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com"); |
| MODULE_DESCRIPTION("nvmem Driver Core"); |
| MODULE_LICENSE("GPL v2"); |