Input: synaptics-rmi4 - add device tree support for RMI4 I2C devices

Add devicetree binding for I2C devices and add bindings for optional
parameters in the function drivers. Parameters for function drivers are
defined in child nodes for each of the functions.

Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
Acked-by: Rob Herring <robh@kernel.org>
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>

drivers/input/rmi4/rmi_bus.c

@@ -153,6 +153,21 @@ static int rmi_function_match(struct device *dev, struct device_driver *drv)
 	return fn->fd.function_number == handler->func;
 }
 
+#ifdef CONFIG_OF
+static void rmi_function_of_probe(struct rmi_function *fn)
+{
+	char of_name[9];
+
+	snprintf(of_name, sizeof(of_name), "rmi4-f%02x",
+		fn->fd.function_number);
+	fn->dev.of_node = of_find_node_by_name(
+				fn->rmi_dev->xport->dev->of_node, of_name);
+}
+#else
+static inline void rmi_function_of_probe(struct rmi_function *fn)
+{}
+#endif
+
 static int rmi_function_probe(struct device *dev)
 {
 	struct rmi_function *fn = to_rmi_function(dev);
@@ -160,6 +175,8 @@ static int rmi_function_probe(struct device *dev)
 					to_rmi_function_handler(dev->driver);
 	int error;
 
+	rmi_function_of_probe(fn);
+
 	if (handler->probe) {
 		error = handler->probe(fn);
 		return error;
@@ -325,6 +342,24 @@ err_unregister_function_handlers:
 	return ret;
 }
 
+int rmi_of_property_read_u32(struct device *dev, u32 *result,
+				const char *prop, bool optional)
+{
+	int retval;
+	u32 val = 0;
+
+	retval = of_property_read_u32(dev->of_node, prop, &val);
+	if (retval && (!optional && retval == -EINVAL)) {
+		dev_err(dev, "Failed to get %s value: %d\n",
+			prop, retval);
+		return retval;
+	}
+	*result = val;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rmi_of_property_read_u32);
+
 static int __init rmi_bus_init(void)
 {
 	int error;

drivers/input/rmi4/rmi_bus.h

@@ -172,10 +172,6 @@ extern struct bus_type rmi_bus_type;
 
 int rmi_of_property_read_u32(struct device *dev, u32 *result,
 				const char *prop, bool optional);
-int rmi_of_property_read_u16(struct device *dev, u16 *result,
-				const char *prop, bool optional);
-int rmi_of_property_read_u8(struct device *dev, u8 *result,
-				const char *prop, bool optional);
 
 #define RMI_DEBUG_CORE			BIT(0)
 #define RMI_DEBUG_XPORT			BIT(1)

drivers/input/rmi4/rmi_driver.c

@@ -20,6 +20,7 @@
 #include <linux/kconfig.h>
 #include <linux/pm.h>
 #include <linux/slab.h>
+#include <linux/of.h>
 #include <uapi/linux/input.h>
 #include <linux/rmi.h>
 #include "rmi_bus.h"
@@ -821,6 +822,27 @@ static int rmi_driver_remove(struct device *dev)
 	return 0;
 }
 
+#ifdef CONFIG_OF
+static int rmi_driver_of_probe(struct device *dev,
+				struct rmi_device_platform_data *pdata)
+{
+	int retval;
+
+	retval = rmi_of_property_read_u32(dev, &pdata->reset_delay_ms,
+					"syna,reset-delay-ms", 1);
+	if (retval)
+		return retval;
+
+	return 0;
+}
+#else
+static inline int rmi_driver_of_probe(struct device *dev,
+					struct rmi_device_platform_data *pdata)
+{
+	return -ENODEV;
+}
+#endif
+
 static int rmi_driver_probe(struct device *dev)
 {
 	struct rmi_driver *rmi_driver;
@@ -846,6 +868,12 @@ static int rmi_driver_probe(struct device *dev)
 
 	pdata = rmi_get_platform_data(rmi_dev);
 
+	if (rmi_dev->xport->dev->of_node) {
+		retval = rmi_driver_of_probe(rmi_dev->xport->dev, pdata);
+		if (retval)
+			return retval;
+	}
+
 	data = devm_kzalloc(dev, sizeof(struct rmi_driver_data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

drivers/input/rmi4/rmi_f01.c

@@ -247,6 +247,50 @@ char *rmi_f01_get_product_ID(struct rmi_function *fn)
 	return f01->properties.product_id;
 }
 
+#ifdef CONFIG_OF
+static int rmi_f01_of_probe(struct device *dev,
+				struct rmi_device_platform_data *pdata)
+{
+	int retval;
+	u32 val;
+
+	retval = rmi_of_property_read_u32(dev,
+			(u32 *)&pdata->power_management.nosleep,
+			"syna,nosleep-mode", 1);
+	if (retval)
+		return retval;
+
+	retval = rmi_of_property_read_u32(dev, &val,
+			"syna,wakeup-threshold", 1);
+	if (retval)
+		return retval;
+
+	pdata->power_management.wakeup_threshold = val;
+
+	retval = rmi_of_property_read_u32(dev, &val,
+			"syna,doze-holdoff-ms", 1);
+	if (retval)
+		return retval;
+
+	pdata->power_management.doze_holdoff = val * 100;
+
+	retval = rmi_of_property_read_u32(dev, &val,
+			"syna,doze-interval-ms", 1);
+	if (retval)
+		return retval;
+
+	pdata->power_management.doze_interval = val / 10;
+
+	return 0;
+}
+#else
+static inline int rmi_f01_of_probe(struct device *dev,
+					struct rmi_device_platform_data *pdata)
+{
+	return -ENODEV;
+}
+#endif
+
 static int rmi_f01_probe(struct rmi_function *fn)
 {
 	struct rmi_device *rmi_dev = fn->rmi_dev;
@@ -258,6 +302,12 @@ static int rmi_f01_probe(struct rmi_function *fn)
 	u8 device_status;
 	u8 temp;
 
+	if (fn->dev.of_node) {
+		error = rmi_f01_of_probe(&fn->dev, pdata);
+		if (error)
+			return error;
+	}
+
 	f01 = devm_kzalloc(&fn->dev, sizeof(struct f01_data), GFP_KERNEL);
 	if (!f01)
 		return -ENOMEM;

drivers/input/rmi4/rmi_i2c.c

@@ -10,6 +10,7 @@
 #include <linux/i2c.h>
 #include <linux/rmi.h>
 #include <linux/irq.h>
+#include <linux/of.h>
 #include "rmi_driver.h"
 
 #define BUFFER_SIZE_INCREMENT 32
@@ -207,6 +208,14 @@ static int rmi_i2c_init_irq(struct i2c_client *client)
 	return 0;
 }
 
+#ifdef CONFIG_OF
+static const struct of_device_id rmi_i2c_of_match[] = {
+	{ .compatible = "syna,rmi4-i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rmi_i2c_of_match);
+#endif
+
 static int rmi_i2c_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
@@ -223,7 +232,7 @@ static int rmi_i2c_probe(struct i2c_client *client,
 
 	pdata = &rmi_i2c->xport.pdata;
 
-	if (client_pdata)
+	if (!client->dev.of_node && client_pdata)
 		*pdata = *client_pdata;
 
 	if (client->irq > 0)
@@ -372,6 +381,7 @@ static struct i2c_driver rmi_i2c_driver = {
 	.driver = {
 		.name	= "rmi4_i2c",
 		.pm	= &rmi_i2c_pm,
+		.of_match_table = of_match_ptr(rmi_i2c_of_match),
 	},
 	.id_table	= rmi_id,
 	.probe		= rmi_i2c_probe,