Add a transport driver for devices using RMI4 over SPI.
Signed-off-by: Andrew Duggan <adug...@synaptics.com>
---
.../devicetree/bindings/input/rmi4/rmi_spi.txt | 57 +++
drivers/input/rmi4/Kconfig | 9 +
drivers/input/rmi4/Makefile | 1 +
drivers/input/rmi4/rmi_spi.c | 464 +++++++++++++++++++++
include/linux/rmi.h | 2 +
5 files changed, 533 insertions(+)
create mode 100644 Documentation/devicetree/bindings/input/rmi4/rmi_spi.txt
create mode 100644 drivers/input/rmi4/rmi_spi.c
diff --git a/Documentation/devicetree/bindings/input/rmi4/rmi_spi.txt
b/Documentation/devicetree/bindings/input/rmi4/rmi_spi.txt
new file mode 100644
index 0000000..f20366b6
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/rmi4/rmi_spi.txt
@@ -0,0 +1,57 @@
+Synaptics RMI4 SPI Device Binding
+
+The Synaptics RMI4 core is able to support RMI4 devices using differnet
+transports and differnet functions. This file describes the device tree
+bindings for devices using the SPI tranport driver. Complete documentation
+for other transports and functions cen be found ini
+Documentation/devicetree/bindings/input/rmi4.
+
+Required Properties:
+- compatible: syna,rmi-spi
+- reg: Chip select address for the device
+- #address-cells: Set to 1 to indicate that the function child nodes
+ consist of only on uint32 value.
+- #size-cells: Set to 0 to indicate that the function child nodes do not
+ have a size property.
+
+Optional Properties:
+- interrupts: interrupt which the rmi device is connected to.
+- interrupt-parent: The interrupt controller.
+See Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+
+- syna,spi-read-delay: millisecond delay between read byte transfers.
+- syna,spi-write-delay: millisecond delay between write byte transfers.
+
+Function Parameters:
+Parameters specific to RMI functions are contained in child nodes of the rmi
device
+ node. Documentation for the parameters of each function can be found in:
+Documentation/devicetree/bindings/input/rmi4/rmi_f*.txt.
+
+
+
+Example:
+ spi@7000d800 {
+ rmi-spi-dev@0 {
+ compatible = "syna,rmi-spi";
+ reg = <0x0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ spi-max-frequency = <4000000>;
+ spi-cpha;
+ spi-cpol;
+ interrupt-parent = <&gpio>;
+ interrupts = <TEGRA_GPIO(K, 2) 0x2>;
+ syna,spi-read-delay = <30>;
+
+ rmi-f01@1 {
+ reg = <0x1>;
+ syna,nosleep-mode = <1>;
+ };
+
+ rmi-f11@11 {
+ reg = <0x11>;
+ syna,flip-y;
+ syna,sensor-type = <2>;
+ };
+ };
+ };
diff --git a/drivers/input/rmi4/Kconfig b/drivers/input/rmi4/Kconfig
index 5e3890e..88a3919 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_F11
bool "RMI4 Function 11 (2D pointing)"
depends on RMI4_CORE
diff --git a/drivers/input/rmi4/Makefile b/drivers/input/rmi4/Makefile
index 37b6789..1745757 100644
--- a/drivers/input/rmi4/Makefile
+++ b/drivers/input/rmi4/Makefile
@@ -6,5 +6,6 @@ rmi_core-$(CONFIG_RMI4_F11) += rmi_f11.o
# Transports
obj-$(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..1b6c258
--- /dev/null
+++ b/drivers/input/rmi4/rmi_spi.c
@@ -0,0 +1,464 @@
+/*
+ * Copyright (c) 2011, 2012 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/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_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,
+};
+
+#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,
+ "syna,spi-read-delay", 1);
+ if (retval)
+ return retval;
+
+ retval = rmi_of_property_read_u32(dev,
+ &pdata->spi_data.write_delay_us,
+ "syna,spi-write-delay", 1);
+ if (retval)
+ return retval;
+
+ return 0;
+}
+
+static const struct of_device_id rmi_spi_of_match[] = {
+ { .compatible = "syna,rmi-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 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->dev.of_node) {
+ retval = rmi_spi_of_probe(spi, pdata);
+ if (retval)
+ return retval;
+ } 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;
+
+ 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",
+ .of_match_table = of_match_ptr(rmi_spi_of_match),
+ },
+ .id_table = rmi_id,
+ .probe = rmi_spi_probe,
+ .remove = rmi_spi_remove,
+};
+
+module_spi_driver(rmi_spi_driver);
+
+MODULE_AUTHOR("Christopher Heiny <che...@synaptics.com>");
+MODULE_AUTHOR("Andrew Duggan <adug...@synaptics.com>");
+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 fef482a..c781d09 100644
--- a/include/linux/rmi.h
+++ b/include/linux/rmi.h
@@ -205,6 +205,8 @@ struct rmi_device_platform_data_spi {
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);
--
2.1.4
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