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Subject[PATCH v4 09/10] Input: synaptics-rmi4: Add device tree support to the SPI transport driver
Date
Add devicetree binding for SPI devices.

Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
---
.../devicetree/bindings/input/rmi4/rmi_spi.txt | 57 ++++++++++++++++++++++
Documentation/devicetree/bindings/spi/spi-bus.txt | 2 +
drivers/input/rmi4/rmi_spi.c | 44 ++++++++++++++++-
3 files changed, 102 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/input/rmi4/rmi_spi.txt

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..66af26b
--- /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 different
+transports and different functions. This file describes the device tree
+bindings for devices using the SPI transport driver. Complete documentation
+for other transports and functions can be found in
+Documentation/devicetree/bindings/input/rmi4.
+
+Required Properties:
+- compatible: syna,rmi4-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
+
+- spi-rx-delay-us: microsecond delay after a read transfer.
+- spi-tx-delay-us: microsecond delay after a write transfer.
+
+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 {
+ rmi4-spi-dev@0 {
+ compatible = "syna,rmi4-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>;
+ spi-rx-delay-us = <30>;
+
+ rmi4-f01@1 {
+ reg = <0x1>;
+ syna,nosleep-mode = <1>;
+ };
+
+ rmi4-f11@11 {
+ reg = <0x11>;
+ touchscreen-inverted-y;
+ syna,sensor-type = <2>;
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
index bbaa857..42d5954 100644
--- a/Documentation/devicetree/bindings/spi/spi-bus.txt
+++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -61,6 +61,8 @@ contain the following properties.
used for MOSI. Defaults to 1 if not present.
- spi-rx-bus-width - (optional) The bus width(number of data wires) that
used for MISO. Defaults to 1 if not present.
+- spi-rx-delay-us - (optional) Microsecond delay after a read transfer.
+- spi-tx-delay-us - (optional) Microsecond delay after a write transfer.

Some SPI controllers and devices support Dual and Quad SPI transfer mode.
It allows data in the SPI system to be transferred in 2 wires(DUAL) or 4 wires(QUAD).
diff --git a/drivers/input/rmi4/rmi_spi.c b/drivers/input/rmi4/rmi_spi.c
index 229944d..ec11d14 100644
--- a/drivers/input/rmi4/rmi_spi.c
+++ b/drivers/input/rmi4/rmi_spi.c
@@ -13,6 +13,7 @@
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/irq.h>
+#include <linux/of.h>
#include "rmi_driver.h"

#define RMI_SPI_DEFAULT_XFER_BUF_SIZE 64
@@ -360,6 +361,41 @@ static int rmi_spi_init_irq(struct spi_device *spi)
return 0;
}

+#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 int rmi_spi_probe(struct spi_device *spi)
{
struct rmi_spi_xport *rmi_spi;
@@ -377,8 +413,13 @@ static int rmi_spi_probe(struct spi_device *spi)

pdata = &rmi_spi->xport.pdata;

- if (spi_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;
@@ -533,6 +574,7 @@ static struct spi_driver rmi_spi_driver = {
.owner = THIS_MODULE,
.name = "rmi4_spi",
.pm = &rmi_spi_pm,
+ .of_match_table = of_match_ptr(rmi_spi_of_match),
},
.id_table = rmi_id,
.probe = rmi_spi_probe,
--
2.5.0
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