input: gpio_keys: Add support for pinctrl framework

Add pinctrl framework support for gpio configuration
to gpio_keys driver.

Signed-off-by: Shantanu Jain <shjain@codeaurora.org>
Change-Id: I50c46caca0a65f8906f816e04f89610497956eea

2 files changed, 137 insertions, 3 deletions

diff --git a/Documentation/devicetree/bindings/gpio/gpio_keys.txt b/Documentation/devicetree/bindings/gpio/gpio_keys.txt
new file mode 100644
index 000000000000..0a9b31a946ec
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio_keys.txt
@@ -0,0 +1,49 @@
+Device-Tree bindings for input/gpio_keys.c keyboard driver
+
+Required properties:
+	- compatible = "gpio-keys";
+
+Optional properties:
+	- input-name: input name of the device.
+	- autorepeat: Boolean, Enable auto repeat feature of Linux input subsystem.
+	- pinctrl-names : This should be defined if a target uses pinctrl framework.
+			See "pinctrl" in Documentation/devicetree/bindings/pinctrl/msm-pinctrl.txt.
+			It should specify the names of the configs that pinctrl can install in drive.
+
+			Following are the pinctrl configs that can be installed:
+			"gpio_ts_active" : Active configuration of pins, this should specify active
+			config defined in pin groups of interrupt and reset gpio.
+			"gpio_ts_suspend" : Disabled configuration of pins, this should specify sleep
+			config defined in pin groups of interrupt and reset gpio.
+
+Each button (key) is represented as a sub-node of "gpio-keys":
+Subnode properties:
+
+	- gpios: OF device-tree gpio specification.
+	- label: Descriptive name of the key.
+	- linux,code: Keycode to emit.
+
+Optional subnode-properties:
+	- linux,input-type: Specify event type this button/key generates.
+	  If not specified defaults to <1> == EV_KEY.
+	- debounce-interval: Debouncing interval time in milliseconds.
+	  If not specified defaults to 5.
+	- gpio-key,wakeup: Boolean, button can wake-up the system.
+
+Example nodes:
+
+gpio_keys {
+		compatible = "gpio-keys";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		autorepeat;
+		input-name = "gpio-keys";
+		pinctrl-names = "tlmm_gpio_key_active","tlmm_gpio_key_suspend";
+		pinctrl-0 = <&gpio_key_active>;
+		pinctrl-1 = <&gpio_key_suspend>;
+		button@21 {
+			label = "GPIO Key UP";
+			linux,code = <103>;
+			gpios = <&gpio1 0 1>;
+		};
+};
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index cbf603ed5916..517b08b3bc0c 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -31,6 +31,7 @@
 #include <linux/of_gpio.h>
 #include <linux/of_irq.h>
 #include <linux/spinlock.h>
+#include <linux/pinctrl/consumer.h>
 
 struct gpio_button_data {
 	const struct gpio_keys_button *button;
@@ -50,6 +51,7 @@ struct gpio_button_data {
 
 struct gpio_keys_drvdata {
 	const struct gpio_keys_platform_data *pdata;
+	struct pinctrl *key_pinctrl;
 	struct input_dev *input;
 	struct mutex disable_lock;
 	struct gpio_button_data data[0];
@@ -564,6 +566,41 @@ static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
 	input_sync(input);
 }
 
+static int gpio_keys_pinctrl_configure(struct gpio_keys_drvdata *ddata,
+							bool active)
+{
+	struct pinctrl_state *set_state;
+	int retval;
+
+	if (active) {
+		set_state =
+			pinctrl_lookup_state(ddata->key_pinctrl,
+						"tlmm_gpio_key_active");
+		if (IS_ERR(set_state)) {
+			dev_err(&ddata->input->dev,
+				"cannot get ts pinctrl active state\n");
+			return PTR_ERR(set_state);
+		}
+	} else {
+		set_state =
+			pinctrl_lookup_state(ddata->key_pinctrl,
+						"tlmm_gpio_key_suspend");
+		if (IS_ERR(set_state)) {
+			dev_err(&ddata->input->dev,
+				"cannot get gpiokey pinctrl sleep state\n");
+			return PTR_ERR(set_state);
+		}
+	}
+	retval = pinctrl_select_state(ddata->key_pinctrl, set_state);
+	if (retval) {
+		dev_err(&ddata->input->dev,
+				"cannot set ts pinctrl active state\n");
+		return retval;
+	}
+
+	return 0;
+}
+
 static int gpio_keys_open(struct input_dev *input)
 {
 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
@@ -708,6 +745,7 @@ static int gpio_keys_probe(struct platform_device *pdev)
 	size_t size;
 	int i, error;
 	int wakeup = 0;
+	struct pinctrl_state *set_state;
 
 	if (!pdata) {
 		pdata = gpio_keys_get_devtree_pdata(dev);
@@ -751,13 +789,31 @@ static int gpio_keys_probe(struct platform_device *pdev)
 	if (pdata->rep)
 		__set_bit(EV_REP, input->evbit);
 
+	/* Get pinctrl if target uses pinctrl */
+	ddata->key_pinctrl = devm_pinctrl_get(dev);
+	if (IS_ERR(ddata->key_pinctrl)) {
+		if (PTR_ERR(ddata->key_pinctrl) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		pr_debug("Target does not use pinctrl\n");
+		ddata->key_pinctrl = NULL;
+	}
+
+	if (ddata->key_pinctrl) {
+		error = gpio_keys_pinctrl_configure(ddata, true);
+		if (error) {
+			dev_err(dev, "cannot set ts pinctrl active state\n");
+			return error;
+		}
+	}
+
 	for (i = 0; i < pdata->nbuttons; i++) {
 		const struct gpio_keys_button *button = &pdata->buttons[i];
 		struct gpio_button_data *bdata = &ddata->data[i];
 
 		error = gpio_keys_setup_key(pdev, input, bdata, button);
 		if (error)
-			return error;
+			goto err_setup_key;
 
 		if (button->wakeup)
 			wakeup = 1;
@@ -767,7 +823,7 @@ static int gpio_keys_probe(struct platform_device *pdev)
 	if (error) {
 		dev_err(dev, "Unable to export keys/switches, error: %d\n",
 			error);
-		return error;
+		goto err_create_sysfs;
 	}
 
 	error = input_register_device(input);
@@ -783,6 +839,18 @@ static int gpio_keys_probe(struct platform_device *pdev)
 
 err_remove_group:
 	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
+err_create_sysfs:
+err_setup_key:
+	if (ddata->key_pinctrl) {
+		set_state =
+		pinctrl_lookup_state(ddata->key_pinctrl,
+						"tlmm_gpio_key_suspend");
+		if (IS_ERR(set_state))
+			dev_err(dev, "cannot get gpiokey pinctrl sleep state\n");
+		else
+			pinctrl_select_state(ddata->key_pinctrl, set_state);
+	}
+
 	return error;
 }
 
@@ -800,7 +868,7 @@ static int gpio_keys_suspend(struct device *dev)
 {
 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 	struct input_dev *input = ddata->input;
-	int i;
+	int i, ret;
 
 	if (device_may_wakeup(dev)) {
 		for (i = 0; i < ddata->pdata->nbuttons; i++) {
@@ -815,6 +883,14 @@ static int gpio_keys_suspend(struct device *dev)
 		mutex_unlock(&input->mutex);
 	}
 
+	if (ddata->key_pinctrl) {
+		ret = gpio_keys_pinctrl_configure(ddata, false);
+		if (ret) {
+			dev_err(dev, "failed to put the pin in suspend state\n");
+			return ret;
+		}
+	}
+
 	return 0;
 }
 
@@ -841,6 +917,15 @@ static int gpio_keys_resume(struct device *dev)
 	if (error)
 		return error;
 
+	if (ddata->key_pinctrl) {
+		error = gpio_keys_pinctrl_configure(ddata, true);
+		if (error) {
+			dev_err(dev, "failed to put the pin in resume state\n");
+			return error;
+		}
+	}
+
+
 	gpio_keys_report_state(ddata);
 	return 0;
 }