input: gpio_keys_polled: Add support for GPIO descriptors

GPIO descriptors are the preferred way over legacy GPIO numbers
nowadays. Convert the driver to use GPIO descriptors internally but
still allow passing legacy GPIO numbers from platform data to support
existing platforms.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/input/keyboard/gpio_keys_polled.c

@@ -23,6 +23,7 @@
 #include <linux/ioport.h>
 #include <linux/platform_device.h>
 #include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/gpio_keys.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
@@ -51,15 +52,14 @@ static void gpio_keys_polled_check_state(struct input_dev *input,
 	int state;
 
 	if (bdata->can_sleep)
-		state = !!gpio_get_value_cansleep(button->gpio);
+		state = !!gpiod_get_value_cansleep(button->gpiod);
 	else
-		state = !!gpio_get_value(button->gpio);
+		state = !!gpiod_get_value(button->gpiod);
 
 	if (state != bdata->last_state) {
 		unsigned int type = button->type ?: EV_KEY;
 
-		input_event(input, type, button->code,
-			    !!(state ^ button->active_low));
+		input_event(input, type, button->code, state);
 		input_sync(input);
 		bdata->count = 0;
 		bdata->last_state = state;
@@ -259,7 +259,6 @@ static int gpio_keys_polled_probe(struct platform_device *pdev)
 	for (i = 0; i < pdata->nbuttons; i++) {
 		struct gpio_keys_button *button = &pdata->buttons[i];
 		struct gpio_keys_button_data *bdata = &bdev->data[i];
-		unsigned int gpio = button->gpio;
 		unsigned int type = button->type ?: EV_KEY;
 
 		if (button->wakeup) {
@@ -267,15 +266,31 @@ static int gpio_keys_polled_probe(struct platform_device *pdev)
 			return -EINVAL;
 		}
 
-		error = devm_gpio_request_one(&pdev->dev, gpio, GPIOF_IN,
-					      button->desc ? : DRV_NAME);
-		if (error) {
-			dev_err(dev, "unable to claim gpio %u, err=%d\n",
-				gpio, error);
-			return error;
+		/*
+		 * Legacy GPIO number so request the GPIO here and
+		 * convert it to descriptor.
+		 */
+		if (!button->gpiod && gpio_is_valid(button->gpio)) {
+			unsigned flags = 0;
+
+			if (button->active_low)
+				flags |= GPIOF_ACTIVE_LOW;
+
+			error = devm_gpio_request_one(&pdev->dev, button->gpio,
+					flags, button->desc ? : DRV_NAME);
+			if (error) {
+				dev_err(dev, "unable to claim gpio %u, err=%d\n",
+					button->gpio, error);
+				return error;
+			}
+
+			button->gpiod = gpio_to_desc(button->gpio);
 		}
 
-		bdata->can_sleep = gpio_cansleep(gpio);
+		if (IS_ERR(button->gpiod))
+			return PTR_ERR(button->gpiod);
+
+		bdata->can_sleep = gpiod_cansleep(button->gpiod);
 		bdata->last_state = -1;
 		bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
 						pdata->poll_interval);

include/linux/gpio_keys.h

@@ -2,6 +2,7 @@
 #define _GPIO_KEYS_H
 
 struct device;
+struct gpio_desc;
 
 /**
  * struct gpio_keys_button - configuration parameters
@@ -17,6 +18,7 @@ struct device;
  *			disable button via sysfs
  * @value:		axis value for %EV_ABS
  * @irq:		Irq number in case of interrupt keys
+ * @gpiod:		GPIO descriptor
  */
 struct gpio_keys_button {
 	unsigned int code;
@@ -29,6 +31,7 @@ struct gpio_keys_button {
 	bool can_disable;
 	int value;
 	unsigned int irq;
+	struct gpio_desc *gpiod;
 };
 
 /**