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author | Andrew Duggan <aduggan@synaptics.com> | 2016-03-11 00:58:12 +0100 |
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committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2016-03-11 01:04:24 +0100 |
commit | 8d99758dee31ff4a72bfc35d3a7a51fe66b7bb91 (patch) | |
tree | 9e7340924294bcfe1d825ee1bd138fd2c1976acf /drivers/input/rmi4/rmi_spi.c | |
parent | Input: synaptics-rmi4 - add support for F30 (diff) | |
download | linux-8d99758dee31ff4a72bfc35d3a7a51fe66b7bb91.tar.xz linux-8d99758dee31ff4a72bfc35d3a7a51fe66b7bb91.zip |
Input: synaptics-rmi4 - add SPI transport driver
Add the transport driver for devices using RMI4 over SPI.
Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input/rmi4/rmi_spi.c')
-rw-r--r-- | drivers/input/rmi4/rmi_spi.c | 547 |
1 files changed, 547 insertions, 0 deletions
diff --git a/drivers/input/rmi4/rmi_spi.c b/drivers/input/rmi4/rmi_spi.c new file mode 100644 index 000000000000..4319c634553f --- /dev/null +++ b/drivers/input/rmi4/rmi_spi.c @@ -0,0 +1,547 @@ +/* + * Copyright (c) 2011-2016 Synaptics Incorporated + * Copyright (c) 2011 Unixphere + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/rmi.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> +#include <linux/irq.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; + + int irq; + + 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_kzalloc(&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_kzalloc(&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) + rmi_spi_manage_pools(rmi_spi, len); + + 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_usecs = spi_data->write_delay_us; + 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_usecs = spi_data->read_delay_us; + 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, +}; + +static irqreturn_t rmi_spi_irq(int irq, void *dev_id) +{ + struct rmi_spi_xport *rmi_spi = dev_id; + struct rmi_device *rmi_dev = rmi_spi->xport.rmi_dev; + int ret; + + ret = rmi_process_interrupt_requests(rmi_dev); + if (ret) + rmi_dbg(RMI_DEBUG_XPORT, &rmi_dev->dev, + "Failed to process interrupt request: %d\n", ret); + + return IRQ_HANDLED; +} + +static int rmi_spi_init_irq(struct spi_device *spi) +{ + struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi); + int irq_flags = irqd_get_trigger_type(irq_get_irq_data(rmi_spi->irq)); + int ret; + + if (!irq_flags) + irq_flags = IRQF_TRIGGER_LOW; + + ret = devm_request_threaded_irq(&spi->dev, rmi_spi->irq, NULL, + rmi_spi_irq, irq_flags | IRQF_ONESHOT, + dev_name(&spi->dev), rmi_spi); + if (ret < 0) { + dev_warn(&spi->dev, "Failed to register interrupt %d\n", + rmi_spi->irq); + return ret; + } + + return 0; +} + +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 retval; + + if (spi->master->flags & SPI_MASTER_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_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; + + retval = spi_setup(spi); + if (retval < 0) { + dev_err(&spi->dev, "spi_setup failed!\n"); + return retval; + } + + if (spi->irq > 0) + rmi_spi->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); + + retval = rmi_spi_manage_pools(rmi_spi, RMI_SPI_DEFAULT_XFER_BUF_SIZE); + if (retval) + return retval; + + /* + * 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. + */ + retval = rmi_set_page(rmi_spi, 0); + if (retval) { + dev_err(&spi->dev, "Failed to set page select to 0.\n"); + return retval; + } + + retval = rmi_register_transport_device(&rmi_spi->xport); + if (retval) { + dev_err(&spi->dev, "failed to register transport.\n"); + return retval; + } + + retval = rmi_spi_init_irq(spi); + if (retval < 0) + return retval; + + dev_info(&spi->dev, "registered RMI SPI driver\n"); + return 0; +} + +static int rmi_spi_remove(struct spi_device *spi) +{ + struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi); + + rmi_unregister_transport_device(&rmi_spi->xport); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +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); + if (ret) + dev_warn(dev, "Failed to resume device: %d\n", ret); + + disable_irq(rmi_spi->irq); + if (device_may_wakeup(&spi->dev)) { + ret = enable_irq_wake(rmi_spi->irq); + if (!ret) + dev_warn(dev, "Failed to enable irq for wake: %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; + + enable_irq(rmi_spi->irq); + if (device_may_wakeup(&spi->dev)) { + ret = disable_irq_wake(rmi_spi->irq); + if (!ret) + dev_warn(dev, "Failed to disable irq for wake: %d\n", + ret); + } + + ret = rmi_driver_resume(rmi_spi->xport.rmi_dev); + if (ret) + dev_warn(dev, "Failed to resume device: %d\n", ret); + + return ret; +} +#endif + +#ifdef CONFIG_PM +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); + if (ret) + dev_warn(dev, "Failed to resume device: %d\n", ret); + + disable_irq(rmi_spi->irq); + + 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; + + enable_irq(rmi_spi->irq); + + ret = rmi_driver_resume(rmi_spi->xport.rmi_dev); + if (ret) + dev_warn(dev, "Failed to resume device: %d\n", ret); + + return 0; +} +#endif + +static const struct dev_pm_ops rmi_spi_pm = { + SET_SYSTEM_SLEEP_PM_OPS(rmi_spi_suspend, rmi_spi_resume) + SET_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 = &rmi_spi_pm, + }, + .id_table = rmi_id, + .probe = rmi_spi_probe, + .remove = rmi_spi_remove, +}; + +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"); +MODULE_VERSION(RMI_DRIVER_VERSION); |