Add the transport driver for devices using RMI4 over SPI.
Signed-off-by: Andrew Duggan <aduggan@xxxxxxxxxxxxx>
---
drivers/input/rmi4/Kconfig | 9 +
drivers/input/rmi4/Makefile | 1 +
drivers/input/rmi4/rmi_spi.c | 422 +++++++++++++++++++++++++++++++++++++++++++
include/linux/rmi.h | 53 ++++++
4 files changed, 485 insertions(+)
create mode 100644 drivers/input/rmi4/rmi_spi.c
diff --git a/drivers/input/rmi4/Kconfig b/drivers/input/rmi4/Kconfig
index 3668c1a..359e75e 100644
--- a/drivers/input/rmi4/Kconfig
+++ b/drivers/input/rmi4/Kconfig
@@ -36,6 +36,15 @@ config RMI4_I2C
This feature is not currently available as a loadable module.
+config RMI4_SPI
+ tristate "RMI4 SPI Support"
+ depends on RMI4_CORE && SPI
+ help
+ Say Y here if you want to support RMI4 devices connected to a SPI
+ bus.
+
+ If unsure, say N.
+
config RMI4_2D_SENSOR
bool
depends on RMI4_CORE
diff --git a/drivers/input/rmi4/Makefile b/drivers/input/rmi4/Makefile
index 16b3c60..766957a 100644
--- a/drivers/input/rmi4/Makefile
+++ b/drivers/input/rmi4/Makefile
@@ -10,5 +10,6 @@ rmi_core-$(CONFIG_RMI4_F30) += rmi_f30.o
# Transports
obj-$(CONFIG_RMI4_I2C) += rmi_i2c.o
+obj-$(CONFIG_RMI4_SPI) += rmi_spi.o
ccflags-$(CONFIG_RMI4_DEBUG) += -DDEBUG
diff --git a/drivers/input/rmi4/rmi_spi.c b/drivers/input/rmi4/rmi_spi.c
new file mode 100644
index 0000000..7f9a188
--- /dev/null
+++ b/drivers/input/rmi4/rmi_spi.c
@@ -0,0 +1,422 @@
+/*
+ * Copyright (c) 2011-2015 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 "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_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);
+ }
+
+ dev_dbg(&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);
+ dev_dbg(&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 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;
+ }
+
+ 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;
+ rmi_spi->xport.irq = spi->irq;
+
+ 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;
+ }
+
+ spi_set_drvdata(spi, rmi_spi);
+
+ 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;
+}
+
+static const struct spi_device_id rmi_id[] = {
+ { "rmi_spi", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, rmi_id);
+
+static struct spi_driver rmi_spi_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "rmi_spi",
+ },
+ .id_table = rmi_id,
+ .probe = rmi_spi_probe,
+ .remove = rmi_spi_remove,
+};
+
+module_spi_driver(rmi_spi_driver);
+
+MODULE_AUTHOR("Christopher Heiny <cheiny@xxxxxxxxxxxxx>");
+MODULE_AUTHOR("Andrew Duggan <aduggan@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("RMI SPI driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(RMI_DRIVER_VERSION);
diff --git a/include/linux/rmi.h b/include/linux/rmi.h
index 6bc5bc9..b0cbb7e 100644
--- a/include/linux/rmi.h
+++ b/include/linux/rmi.h
@@ -150,6 +150,55 @@ struct rmi_f01_power_management {
};
/**
+ * struct rmi_device_platform_data_spi - provides parameters used in SPI
+ * communications. All Synaptics SPI products support a standard SPI
+ * interface; some also support what is called SPI V2 mode, depending on
+ * firmware and/or ASIC limitations. In V2 mode, the touch sensor can
+ * support shorter delays during certain operations, and these are specified
+ * separately from the standard mode delays.
+ *
+ * @block_delay - for standard SPI transactions consisting of both a read and
+ * write operation, the delay (in microseconds) between the read and write
+ * operations.
+ * @split_read_block_delay_us - for V2 SPI transactions consisting of both a
+ * read and write operation, the delay (in microseconds) between the read and
+ * write operations.
+ * @read_delay_us - the delay between each byte of a read operation in normal
+ * SPI mode.
+ * @write_delay_us - the delay between each byte of a write operation in normal
+ * SPI mode.
+ * @split_read_byte_delay_us - the delay between each byte of a read operation
+ * in V2 mode.
+ * @pre_delay_us - the delay before the start of a SPI transaction. This is
+ * typically useful in conjunction with custom chip select assertions (see
+ * below).
+ * @post_delay_us - the delay after the completion of an SPI transaction. This
+ * is typically useful in conjunction with custom chip select assertions (see
+ * below).
+ * @cs_assert - For systems where the SPI subsystem does not control the CS/SSB
+ * line, or where such control is broken, you can provide a custom routine to
+ * handle a GPIO as CS/SSB. This routine will be called at the beginning and
+ * end of each SPI transaction. The RMI SPI implementation will wait
+ * pre_delay_us after this routine returns before starting the SPI transfer;
+ * and post_delay_us after completion of the SPI transfer(s) before calling it
+ * with assert==FALSE.
+ */
+struct rmi_device_platform_data_spi {
+ u32 block_delay_us;
+ u32 split_read_block_delay_us;
+ u32 read_delay_us;
+ u32 write_delay_us;
+ u32 split_read_byte_delay_us;
+ u32 pre_delay_us;
+ u32 post_delay_us;
+ u8 bits_per_word;
+ u16 mode;
+
+ void *cs_assert_data;
+ int (*cs_assert)(const void *cs_assert_data, const bool assert);
+};
+
+/**
* struct rmi_device_platform_data - system specific configuration info.
*
* @irq_flags - this is used to specify intrerrupt type flags.
@@ -158,6 +207,8 @@ struct rmi_f01_power_management {
* driver waits a few milliseconds to give the firmware a chance to
* to re-initialize. You can override the default wait period here.
*
+ * @spi_data - override default settings for SPI delays and SSB management (see
+ * above).
*
* @pre_suspend - this will be called before any other suspend operations are
* done.
@@ -179,6 +230,8 @@ struct rmi_device_platform_data {
int reset_delay_ms;
+ struct rmi_device_platform_data_spi spi_data;
+
/* function handler pdata */
struct rmi_2d_sensor_platform_data *sensor_pdata;
struct rmi_f01_power_management power_management;
--
2.5.0
--
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