[PATCH v5 09/10] Input: synaptics-rmi4: Add device tree support to the SPI transport driver

* [PATCH v5 09/10] Input: synaptics-rmi4: Add device tree support to the SPI transport driver
@ 2016-02-10 22:25 ` Andrew Duggan
  0 siblings, 0 replies; 4+ messages in thread
From: Andrew Duggan @ 2016-02-10 22:25 UTC (permalink / raw)
  To: linux-input, linux-kernel
  Cc: Andrew Duggan, Dmitry Torokhov, Linus Walleij, Jiri Kosina,
	Benjamin Tissoires, Christopher Heiny, Stephen Chandler Paul,
	Vincent Huang, Chris Healy, Andrey Gusakov, Rob Herring,
	devicetree

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..a4ca782
--- /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 4319c63..55bd1b3 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;
@@ -532,6 +573,7 @@ static struct spi_driver rmi_spi_driver = {
 	.driver = {
 		.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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