Input: gpio_mouse - convert to use GPIO descriptors

This converts the GPIO mouse to use descriptors and fwnode properties. The
polarity settings go out the window since GPIO descriptor already know
about polarity so this should be configured in device tree or ACPI or
similar.

Set scanning interval by default to 50ms if not found as a property on the
device.

Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/gpio_mouse.c

@@ -2,6 +2,7 @@
  * Driver for simulating a mouse on GPIO lines.
  *
  * Copyright (C) 2007 Atmel Corporation
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -11,24 +12,12 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/input-polldev.h>
-#include <linux/gpio.h>
-
-#define GPIO_MOUSE_POLARITY_ACT_HIGH	0x00
-#define GPIO_MOUSE_POLARITY_ACT_LOW	0x01
-
-#define GPIO_MOUSE_PIN_UP	0
-#define GPIO_MOUSE_PIN_DOWN	1
-#define GPIO_MOUSE_PIN_LEFT	2
-#define GPIO_MOUSE_PIN_RIGHT	3
-#define GPIO_MOUSE_PIN_BLEFT	4
-#define GPIO_MOUSE_PIN_BMIDDLE	5
-#define GPIO_MOUSE_PIN_BRIGHT	6
-#define GPIO_MOUSE_PIN_MAX	7
+#include <linux/gpio/consumer.h>
+#include <linux/property.h>
 
 /**
  * struct gpio_mouse
- * @scan_ms: integer in ms specifying the scan periode.
- * @polarity: Pin polarity, active high or low.
+ * @scan_ms: the scan interval in milliseconds.
  * @up: GPIO line for up value.
  * @down: GPIO line for down value.
  * @left: GPIO line for left value.
@@ -36,29 +25,20 @@
  * @bleft: GPIO line for left button.
  * @bmiddle: GPIO line for middle button.
  * @bright: GPIO line for right button.
- * @pins: GPIO line numbers used for the mouse.
  *
  * This struct must be added to the platform_device in the board code.
  * It is used by the gpio_mouse driver to setup GPIO lines and to
  * calculate mouse movement.
  */
 struct gpio_mouse {
-	int scan_ms;
-	int polarity;
-
-	union {
-		struct {
-			int up;
-			int down;
-			int left;
-			int right;
-
-			int bleft;
-			int bmiddle;
-			int bright;
-		};
-		int pins[GPIO_MOUSE_PIN_MAX];
-	};
+	u32 scan_ms;
+	struct gpio_desc *up;
+	struct gpio_desc *down;
+	struct gpio_desc *left;
+	struct gpio_desc *right;
+	struct gpio_desc *bleft;
+	struct gpio_desc *bmiddle;
+	struct gpio_desc *bright;
 };
 
 /*
@@ -71,20 +51,18 @@ static void gpio_mouse_scan(struct input_polled_dev *dev)
 	struct input_dev *input = dev->input;
 	int x, y;
 
-	if (gpio->bleft >= 0)
+	if (gpio->bleft)
 		input_report_key(input, BTN_LEFT,
-				gpio_get_value(gpio->bleft) ^ gpio->polarity);
-	if (gpio->bmiddle >= 0)
+				 gpiod_get_value(gpio->bleft));
+	if (gpio->bmiddle)
 		input_report_key(input, BTN_MIDDLE,
-				gpio_get_value(gpio->bmiddle) ^ gpio->polarity);
-	if (gpio->bright >= 0)
+				 gpiod_get_value(gpio->bmiddle));
+	if (gpio->bright)
 		input_report_key(input, BTN_RIGHT,
-				gpio_get_value(gpio->bright) ^ gpio->polarity);
+				 gpiod_get_value(gpio->bright));
 
-	x = (gpio_get_value(gpio->right) ^ gpio->polarity)
-		- (gpio_get_value(gpio->left) ^ gpio->polarity);
-	y = (gpio_get_value(gpio->down) ^ gpio->polarity)
-		- (gpio_get_value(gpio->up) ^ gpio->polarity);
+	x = gpiod_get_value(gpio->right) - gpiod_get_value(gpio->left);
+	y = gpiod_get_value(gpio->down) - gpiod_get_value(gpio->up);
 
 	input_report_rel(input, REL_X, x);
 	input_report_rel(input, REL_Y, y);
@@ -97,52 +75,49 @@ static int gpio_mouse_probe(struct platform_device *pdev)
 	struct gpio_mouse *gmouse;
 	struct input_polled_dev *input_poll;
 	struct input_dev *input;
-	int pin, i;
-	int error;
+	int ret;
 
 	gmouse = devm_kzalloc(dev, sizeof(*gmouse), GFP_KERNEL);
 	if (!gmouse)
 		return -ENOMEM;
 
-	if (gmouse->scan_ms < 0) {
-		dev_err(&pdev->dev, "invalid scan time\n");
-		error = -EINVAL;
-		goto out;
+	/* Assign some default scanning time */
+	ret = device_property_read_u32(dev, "scan-interval-ms",
+				       &gmouse->scan_ms);
+	if (ret || gmouse->scan_ms == 0) {
+		dev_warn(dev, "invalid scan time, set to 50 ms\n");
+		gmouse->scan_ms = 50;
 	}
 
-	for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
-		pin = gmouse->pins[i];
-
-		if (pin < 0) {
-
-			if (i <= GPIO_MOUSE_PIN_RIGHT) {
-				/* Mouse direction is required. */
-				dev_err(&pdev->dev,
-					"missing GPIO for directions\n");
-				error = -EINVAL;
-				goto out_free_gpios;
-			}
-
-			if (i == GPIO_MOUSE_PIN_BLEFT)
-				dev_dbg(&pdev->dev, "no left button defined\n");
-
-		} else {
-			error = gpio_request(pin, "gpio_mouse");
-			if (error) {
-				dev_err(&pdev->dev, "fail %d pin (%d idx)\n",
-					pin, i);
-				goto out_free_gpios;
-			}
-
-			gpio_direction_input(pin);
-		}
-	}
-
-	input_poll = input_allocate_polled_device();
+	gmouse->up = devm_gpiod_get(dev, "up", GPIOD_IN);
+	if (IS_ERR(gmouse->up))
+		return PTR_ERR(gmouse->up);
+	gmouse->down = devm_gpiod_get(dev, "down", GPIOD_IN);
+	if (IS_ERR(gmouse->down))
+		return PTR_ERR(gmouse->down);
+	gmouse->left = devm_gpiod_get(dev, "left", GPIOD_IN);
+	if (IS_ERR(gmouse->left))
+		return PTR_ERR(gmouse->left);
+	gmouse->right = devm_gpiod_get(dev, "right", GPIOD_IN);
+	if (IS_ERR(gmouse->right))
+		return PTR_ERR(gmouse->right);
+
+	gmouse->bleft = devm_gpiod_get_optional(dev, "button-left", GPIOD_IN);
+	if (IS_ERR(gmouse->bleft))
+		return PTR_ERR(gmouse->bleft);
+	gmouse->bmiddle = devm_gpiod_get_optional(dev, "button-middle",
+						  GPIOD_IN);
+	if (IS_ERR(gmouse->bmiddle))
+		return PTR_ERR(gmouse->bmiddle);
+	gmouse->bright = devm_gpiod_get_optional(dev, "button-right",
+						 GPIOD_IN);
+	if (IS_ERR(gmouse->bright))
+		return PTR_ERR(gmouse->bright);
+
+	input_poll = devm_input_allocate_polled_device(dev);
 	if (!input_poll) {
-		dev_err(&pdev->dev, "not enough memory for input device\n");
-		error = -ENOMEM;
-		goto out_free_gpios;
+		dev_err(dev, "not enough memory for input device\n");
+		return -ENOMEM;
 	}
 
 	platform_set_drvdata(pdev, input_poll);
@@ -159,61 +134,30 @@ static int gpio_mouse_probe(struct platform_device *pdev)
 
 	input_set_capability(input, EV_REL, REL_X);
 	input_set_capability(input, EV_REL, REL_Y);
-	if (gmouse->bleft >= 0)
+	if (gmouse->bleft)
 		input_set_capability(input, EV_KEY, BTN_LEFT);
-	if (gmouse->bmiddle >= 0)
+	if (gmouse->bmiddle)
 		input_set_capability(input, EV_KEY, BTN_MIDDLE);
-	if (gmouse->bright >= 0)
+	if (gmouse->bright)
 		input_set_capability(input, EV_KEY, BTN_RIGHT);
 
-	error = input_register_polled_device(input_poll);
-	if (error) {
-		dev_err(&pdev->dev, "could not register input device\n");
-		goto out_free_polldev;
-	}
-
-	dev_dbg(&pdev->dev, "%d ms scan time, buttons: %s%s%s\n",
-			gmouse->scan_ms,
-			gmouse->bleft < 0 ? "" : "left ",
-			gmouse->bmiddle < 0 ? "" : "middle ",
-			gmouse->bright < 0 ? "" : "right");
-
-	return 0;
-
- out_free_polldev:
-	input_free_polled_device(input_poll);
-
- out_free_gpios:
-	while (--i >= 0) {
-		pin = gmouse->pins[i];
-		if (pin)
-			gpio_free(pin);
+	ret = input_register_polled_device(input_poll);
+	if (ret) {
+		dev_err(dev, "could not register input device\n");
+		return ret;
 	}
- out:
-	return error;
-}
 
-static int gpio_mouse_remove(struct platform_device *pdev)
-{
-	struct input_polled_dev *input = platform_get_drvdata(pdev);
-	struct gpio_mouse *gmouse = input->private;
-	int pin, i;
-
-	input_unregister_polled_device(input);
-	input_free_polled_device(input);
-
-	for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
-		pin = gmouse->pins[i];
-		if (pin >= 0)
-			gpio_free(pin);
-	}
+	dev_dbg(dev, "%d ms scan time, buttons: %s%s%s\n",
+		gmouse->scan_ms,
+		gmouse->bleft ? "" : "left ",
+		gmouse->bmiddle ? "" : "middle ",
+		gmouse->bright ? "" : "right");
 
 	return 0;
 }
 
 static struct platform_driver gpio_mouse_device_driver = {
 	.probe		= gpio_mouse_probe,
-	.remove		= gpio_mouse_remove,
 	.driver		= {
 		.name	= "gpio_mouse",
 	}
@@ -224,4 +168,3 @@ MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");
 MODULE_DESCRIPTION("GPIO mouse driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:gpio_mouse"); /* work with hotplug and coldplug */
-