| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (c) 2011-2016 Synaptics Incorporated |
| * Copyright (c) 2011 Unixphere |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/rmi.h> |
| #include <linux/slab.h> |
| #include <linux/spi/spi.h> |
| #include <linux/of.h> |
| #include "rmi_driver.h" |
| |
| #define RMI_SPI_DEFAULT_XFER_BUF_SIZE 64 |
| |
| #define RMI_PAGE_SELECT_REGISTER 0x00FF |
| #define RMI_SPI_PAGE(addr) (((addr) >> 8) & 0x80) |
| #define RMI_SPI_XFER_SIZE_LIMIT 255 |
| |
| #define BUFFER_SIZE_INCREMENT 32 |
| |
| enum rmi_spi_op { |
| RMI_SPI_WRITE = 0, |
| RMI_SPI_READ, |
| RMI_SPI_V2_READ_UNIFIED, |
| RMI_SPI_V2_READ_SPLIT, |
| RMI_SPI_V2_WRITE, |
| }; |
| |
| struct rmi_spi_cmd { |
| enum rmi_spi_op op; |
| u16 addr; |
| }; |
| |
| struct rmi_spi_xport { |
| struct rmi_transport_dev xport; |
| struct spi_device *spi; |
| |
| struct mutex page_mutex; |
| int page; |
| |
| u8 *rx_buf; |
| u8 *tx_buf; |
| int xfer_buf_size; |
| |
| struct spi_transfer *rx_xfers; |
| struct spi_transfer *tx_xfers; |
| int rx_xfer_count; |
| int tx_xfer_count; |
| }; |
| |
| static int rmi_spi_manage_pools(struct rmi_spi_xport *rmi_spi, int len) |
| { |
| struct spi_device *spi = rmi_spi->spi; |
| int buf_size = rmi_spi->xfer_buf_size |
| ? rmi_spi->xfer_buf_size : RMI_SPI_DEFAULT_XFER_BUF_SIZE; |
| struct spi_transfer *xfer_buf; |
| void *buf; |
| void *tmp; |
| |
| while (buf_size < len) |
| buf_size *= 2; |
| |
| if (buf_size > RMI_SPI_XFER_SIZE_LIMIT) |
| buf_size = RMI_SPI_XFER_SIZE_LIMIT; |
| |
| tmp = rmi_spi->rx_buf; |
| buf = devm_kcalloc(&spi->dev, buf_size, 2, |
| GFP_KERNEL | GFP_DMA); |
| if (!buf) |
| return -ENOMEM; |
| |
| rmi_spi->rx_buf = buf; |
| rmi_spi->tx_buf = &rmi_spi->rx_buf[buf_size]; |
| rmi_spi->xfer_buf_size = buf_size; |
| |
| if (tmp) |
| devm_kfree(&spi->dev, tmp); |
| |
| if (rmi_spi->xport.pdata.spi_data.read_delay_us) |
| rmi_spi->rx_xfer_count = buf_size; |
| else |
| rmi_spi->rx_xfer_count = 1; |
| |
| if (rmi_spi->xport.pdata.spi_data.write_delay_us) |
| rmi_spi->tx_xfer_count = buf_size; |
| else |
| rmi_spi->tx_xfer_count = 1; |
| |
| /* |
| * Allocate a pool of spi_transfer buffers for devices which need |
| * per byte delays. |
| */ |
| tmp = rmi_spi->rx_xfers; |
| xfer_buf = devm_kcalloc(&spi->dev, |
| rmi_spi->rx_xfer_count + rmi_spi->tx_xfer_count, |
| sizeof(struct spi_transfer), |
| GFP_KERNEL); |
| if (!xfer_buf) |
| return -ENOMEM; |
| |
| rmi_spi->rx_xfers = xfer_buf; |
| rmi_spi->tx_xfers = &xfer_buf[rmi_spi->rx_xfer_count]; |
| |
| if (tmp) |
| devm_kfree(&spi->dev, tmp); |
| |
| return 0; |
| } |
| |
| static int rmi_spi_xfer(struct rmi_spi_xport *rmi_spi, |
| const struct rmi_spi_cmd *cmd, const u8 *tx_buf, |
| int tx_len, u8 *rx_buf, int rx_len) |
| { |
| struct spi_device *spi = rmi_spi->spi; |
| struct rmi_device_platform_data_spi *spi_data = |
| &rmi_spi->xport.pdata.spi_data; |
| struct spi_message msg; |
| struct spi_transfer *xfer; |
| int ret = 0; |
| int len; |
| int cmd_len = 0; |
| int total_tx_len; |
| int i; |
| u16 addr = cmd->addr; |
| |
| spi_message_init(&msg); |
| |
| switch (cmd->op) { |
| case RMI_SPI_WRITE: |
| case RMI_SPI_READ: |
| cmd_len += 2; |
| break; |
| case RMI_SPI_V2_READ_UNIFIED: |
| case RMI_SPI_V2_READ_SPLIT: |
| case RMI_SPI_V2_WRITE: |
| cmd_len += 4; |
| break; |
| } |
| |
| total_tx_len = cmd_len + tx_len; |
| len = max(total_tx_len, rx_len); |
| |
| if (len > RMI_SPI_XFER_SIZE_LIMIT) |
| return -EINVAL; |
| |
| if (rmi_spi->xfer_buf_size < len) { |
| ret = rmi_spi_manage_pools(rmi_spi, len); |
| if (ret < 0) |
| return ret; |
| } |
| |
| if (addr == 0) |
| /* |
| * SPI needs an address. Use 0x7FF if we want to keep |
| * reading from the last position of the register pointer. |
| */ |
| addr = 0x7FF; |
| |
| switch (cmd->op) { |
| case RMI_SPI_WRITE: |
| rmi_spi->tx_buf[0] = (addr >> 8); |
| rmi_spi->tx_buf[1] = addr & 0xFF; |
| break; |
| case RMI_SPI_READ: |
| rmi_spi->tx_buf[0] = (addr >> 8) | 0x80; |
| rmi_spi->tx_buf[1] = addr & 0xFF; |
| break; |
| case RMI_SPI_V2_READ_UNIFIED: |
| break; |
| case RMI_SPI_V2_READ_SPLIT: |
| break; |
| case RMI_SPI_V2_WRITE: |
| rmi_spi->tx_buf[0] = 0x40; |
| rmi_spi->tx_buf[1] = (addr >> 8) & 0xFF; |
| rmi_spi->tx_buf[2] = addr & 0xFF; |
| rmi_spi->tx_buf[3] = tx_len; |
| break; |
| } |
| |
| if (tx_buf) |
| memcpy(&rmi_spi->tx_buf[cmd_len], tx_buf, tx_len); |
| |
| if (rmi_spi->tx_xfer_count > 1) { |
| for (i = 0; i < total_tx_len; i++) { |
| xfer = &rmi_spi->tx_xfers[i]; |
| memset(xfer, 0, sizeof(struct spi_transfer)); |
| xfer->tx_buf = &rmi_spi->tx_buf[i]; |
| xfer->len = 1; |
| xfer->delay.value = spi_data->write_delay_us; |
| xfer->delay.unit = SPI_DELAY_UNIT_USECS; |
| spi_message_add_tail(xfer, &msg); |
| } |
| } else { |
| xfer = rmi_spi->tx_xfers; |
| memset(xfer, 0, sizeof(struct spi_transfer)); |
| xfer->tx_buf = rmi_spi->tx_buf; |
| xfer->len = total_tx_len; |
| spi_message_add_tail(xfer, &msg); |
| } |
| |
| rmi_dbg(RMI_DEBUG_XPORT, &spi->dev, "%s: cmd: %s tx_buf len: %d tx_buf: %*ph\n", |
| __func__, cmd->op == RMI_SPI_WRITE ? "WRITE" : "READ", |
| total_tx_len, total_tx_len, rmi_spi->tx_buf); |
| |
| if (rx_buf) { |
| if (rmi_spi->rx_xfer_count > 1) { |
| for (i = 0; i < rx_len; i++) { |
| xfer = &rmi_spi->rx_xfers[i]; |
| memset(xfer, 0, sizeof(struct spi_transfer)); |
| xfer->rx_buf = &rmi_spi->rx_buf[i]; |
| xfer->len = 1; |
| xfer->delay.value = spi_data->read_delay_us; |
| xfer->delay.unit = SPI_DELAY_UNIT_USECS; |
| spi_message_add_tail(xfer, &msg); |
| } |
| } else { |
| xfer = rmi_spi->rx_xfers; |
| memset(xfer, 0, sizeof(struct spi_transfer)); |
| xfer->rx_buf = rmi_spi->rx_buf; |
| xfer->len = rx_len; |
| spi_message_add_tail(xfer, &msg); |
| } |
| } |
| |
| ret = spi_sync(spi, &msg); |
| if (ret < 0) { |
| dev_err(&spi->dev, "spi xfer failed: %d\n", ret); |
| return ret; |
| } |
| |
| if (rx_buf) { |
| memcpy(rx_buf, rmi_spi->rx_buf, rx_len); |
| rmi_dbg(RMI_DEBUG_XPORT, &spi->dev, "%s: (%d) %*ph\n", |
| __func__, rx_len, rx_len, rx_buf); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * rmi_set_page - Set RMI page |
| * @xport: The pointer to the rmi_transport_dev struct |
| * @page: The new page address. |
| * |
| * RMI devices have 16-bit addressing, but some of the transport |
| * implementations (like SMBus) only have 8-bit addressing. So RMI implements |
| * a page address at 0xff of every page so we can reliable page addresses |
| * every 256 registers. |
| * |
| * The page_mutex lock must be held when this function is entered. |
| * |
| * Returns zero on success, non-zero on failure. |
| */ |
| static int rmi_set_page(struct rmi_spi_xport *rmi_spi, u8 page) |
| { |
| struct rmi_spi_cmd cmd; |
| int ret; |
| |
| cmd.op = RMI_SPI_WRITE; |
| cmd.addr = RMI_PAGE_SELECT_REGISTER; |
| |
| ret = rmi_spi_xfer(rmi_spi, &cmd, &page, 1, NULL, 0); |
| |
| if (ret) |
| rmi_spi->page = page; |
| |
| return ret; |
| } |
| |
| static int rmi_spi_write_block(struct rmi_transport_dev *xport, u16 addr, |
| const void *buf, size_t len) |
| { |
| struct rmi_spi_xport *rmi_spi = |
| container_of(xport, struct rmi_spi_xport, xport); |
| struct rmi_spi_cmd cmd; |
| int ret; |
| |
| mutex_lock(&rmi_spi->page_mutex); |
| |
| if (RMI_SPI_PAGE(addr) != rmi_spi->page) { |
| ret = rmi_set_page(rmi_spi, RMI_SPI_PAGE(addr)); |
| if (ret) |
| goto exit; |
| } |
| |
| cmd.op = RMI_SPI_WRITE; |
| cmd.addr = addr; |
| |
| ret = rmi_spi_xfer(rmi_spi, &cmd, buf, len, NULL, 0); |
| |
| exit: |
| mutex_unlock(&rmi_spi->page_mutex); |
| return ret; |
| } |
| |
| static int rmi_spi_read_block(struct rmi_transport_dev *xport, u16 addr, |
| void *buf, size_t len) |
| { |
| struct rmi_spi_xport *rmi_spi = |
| container_of(xport, struct rmi_spi_xport, xport); |
| struct rmi_spi_cmd cmd; |
| int ret; |
| |
| mutex_lock(&rmi_spi->page_mutex); |
| |
| if (RMI_SPI_PAGE(addr) != rmi_spi->page) { |
| ret = rmi_set_page(rmi_spi, RMI_SPI_PAGE(addr)); |
| if (ret) |
| goto exit; |
| } |
| |
| cmd.op = RMI_SPI_READ; |
| cmd.addr = addr; |
| |
| ret = rmi_spi_xfer(rmi_spi, &cmd, NULL, 0, buf, len); |
| |
| exit: |
| mutex_unlock(&rmi_spi->page_mutex); |
| return ret; |
| } |
| |
| static const struct rmi_transport_ops rmi_spi_ops = { |
| .write_block = rmi_spi_write_block, |
| .read_block = rmi_spi_read_block, |
| }; |
| |
| #ifdef CONFIG_OF |
| static int rmi_spi_of_probe(struct spi_device *spi, |
| struct rmi_device_platform_data *pdata) |
| { |
| struct device *dev = &spi->dev; |
| int retval; |
| |
| retval = rmi_of_property_read_u32(dev, |
| &pdata->spi_data.read_delay_us, |
| "spi-rx-delay-us", 1); |
| if (retval) |
| return retval; |
| |
| retval = rmi_of_property_read_u32(dev, |
| &pdata->spi_data.write_delay_us, |
| "spi-tx-delay-us", 1); |
| if (retval) |
| return retval; |
| |
| return 0; |
| } |
| |
| static const struct of_device_id rmi_spi_of_match[] = { |
| { .compatible = "syna,rmi4-spi" }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, rmi_spi_of_match); |
| #else |
| static inline int rmi_spi_of_probe(struct spi_device *spi, |
| struct rmi_device_platform_data *pdata) |
| { |
| return -ENODEV; |
| } |
| #endif |
| |
| static void rmi_spi_unregister_transport(void *data) |
| { |
| struct rmi_spi_xport *rmi_spi = data; |
| |
| rmi_unregister_transport_device(&rmi_spi->xport); |
| } |
| |
| static int rmi_spi_probe(struct spi_device *spi) |
| { |
| struct rmi_spi_xport *rmi_spi; |
| struct rmi_device_platform_data *pdata; |
| struct rmi_device_platform_data *spi_pdata = spi->dev.platform_data; |
| int error; |
| |
| if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) |
| return -EINVAL; |
| |
| rmi_spi = devm_kzalloc(&spi->dev, sizeof(struct rmi_spi_xport), |
| GFP_KERNEL); |
| if (!rmi_spi) |
| return -ENOMEM; |
| |
| pdata = &rmi_spi->xport.pdata; |
| |
| if (spi->dev.of_node) { |
| error = rmi_spi_of_probe(spi, pdata); |
| if (error) |
| return error; |
| } else if (spi_pdata) { |
| *pdata = *spi_pdata; |
| } |
| |
| if (pdata->spi_data.bits_per_word) |
| spi->bits_per_word = pdata->spi_data.bits_per_word; |
| |
| if (pdata->spi_data.mode) |
| spi->mode = pdata->spi_data.mode; |
| |
| error = spi_setup(spi); |
| if (error < 0) { |
| dev_err(&spi->dev, "spi_setup failed!\n"); |
| return error; |
| } |
| |
| pdata->irq = spi->irq; |
| |
| rmi_spi->spi = spi; |
| mutex_init(&rmi_spi->page_mutex); |
| |
| rmi_spi->xport.dev = &spi->dev; |
| rmi_spi->xport.proto_name = "spi"; |
| rmi_spi->xport.ops = &rmi_spi_ops; |
| |
| spi_set_drvdata(spi, rmi_spi); |
| |
| error = rmi_spi_manage_pools(rmi_spi, RMI_SPI_DEFAULT_XFER_BUF_SIZE); |
| if (error) |
| return error; |
| |
| /* |
| * Setting the page to zero will (a) make sure the PSR is in a |
| * known state, and (b) make sure we can talk to the device. |
| */ |
| error = rmi_set_page(rmi_spi, 0); |
| if (error) { |
| dev_err(&spi->dev, "Failed to set page select to 0.\n"); |
| return error; |
| } |
| |
| dev_info(&spi->dev, "registering SPI-connected sensor\n"); |
| |
| error = rmi_register_transport_device(&rmi_spi->xport); |
| if (error) { |
| dev_err(&spi->dev, "failed to register sensor: %d\n", error); |
| return error; |
| } |
| |
| error = devm_add_action_or_reset(&spi->dev, |
| rmi_spi_unregister_transport, |
| rmi_spi); |
| if (error) |
| return error; |
| |
| return 0; |
| } |
| |
| static int rmi_spi_suspend(struct device *dev) |
| { |
| struct spi_device *spi = to_spi_device(dev); |
| struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi); |
| int ret; |
| |
| ret = rmi_driver_suspend(rmi_spi->xport.rmi_dev, true); |
| if (ret) |
| dev_warn(dev, "Failed to resume device: %d\n", ret); |
| |
| return ret; |
| } |
| |
| static int rmi_spi_resume(struct device *dev) |
| { |
| struct spi_device *spi = to_spi_device(dev); |
| struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi); |
| int ret; |
| |
| ret = rmi_driver_resume(rmi_spi->xport.rmi_dev, true); |
| if (ret) |
| dev_warn(dev, "Failed to resume device: %d\n", ret); |
| |
| return ret; |
| } |
| |
| static int rmi_spi_runtime_suspend(struct device *dev) |
| { |
| struct spi_device *spi = to_spi_device(dev); |
| struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi); |
| int ret; |
| |
| ret = rmi_driver_suspend(rmi_spi->xport.rmi_dev, false); |
| if (ret) |
| dev_warn(dev, "Failed to resume device: %d\n", ret); |
| |
| return 0; |
| } |
| |
| static int rmi_spi_runtime_resume(struct device *dev) |
| { |
| struct spi_device *spi = to_spi_device(dev); |
| struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi); |
| int ret; |
| |
| ret = rmi_driver_resume(rmi_spi->xport.rmi_dev, false); |
| if (ret) |
| dev_warn(dev, "Failed to resume device: %d\n", ret); |
| |
| return 0; |
| } |
| |
| static const struct dev_pm_ops rmi_spi_pm = { |
| SYSTEM_SLEEP_PM_OPS(rmi_spi_suspend, rmi_spi_resume) |
| RUNTIME_PM_OPS(rmi_spi_runtime_suspend, rmi_spi_runtime_resume, NULL) |
| }; |
| |
| static const struct spi_device_id rmi_id[] = { |
| { "rmi4-spi", 0 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(spi, rmi_id); |
| |
| static struct spi_driver rmi_spi_driver = { |
| .driver = { |
| .name = "rmi4_spi", |
| .pm = pm_ptr(&rmi_spi_pm), |
| .of_match_table = of_match_ptr(rmi_spi_of_match), |
| }, |
| .id_table = rmi_id, |
| .probe = rmi_spi_probe, |
| }; |
| |
| module_spi_driver(rmi_spi_driver); |
| |
| MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com>"); |
| MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>"); |
| MODULE_DESCRIPTION("RMI SPI driver"); |
| MODULE_LICENSE("GPL"); |