1/*
2 * Driver for simulating a mouse on GPIO lines.
3 *
4 * Copyright (C) 2007 Atmel Corporation
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/module.h>
12#include <linux/platform_device.h>
13#include <linux/input-polldev.h>
14#include <linux/gpio.h>
15#include <linux/gpio_mouse.h>
16
17
18/*
19 * Timer function which is run every scan_ms ms when the device is opened.
20 * The dev input variable is set to the the input_dev pointer.
21 */
22static void gpio_mouse_scan(struct input_polled_dev *dev)
23{
24	struct gpio_mouse_platform_data *gpio = dev->private;
25	struct input_dev *input = dev->input;
26	int x, y;
27
28	if (gpio->bleft >= 0)
29		input_report_key(input, BTN_LEFT,
30				gpio_get_value(gpio->bleft) ^ gpio->polarity);
31	if (gpio->bmiddle >= 0)
32		input_report_key(input, BTN_MIDDLE,
33				gpio_get_value(gpio->bmiddle) ^ gpio->polarity);
34	if (gpio->bright >= 0)
35		input_report_key(input, BTN_RIGHT,
36				gpio_get_value(gpio->bright) ^ gpio->polarity);
37
38	x = (gpio_get_value(gpio->right) ^ gpio->polarity)
39		- (gpio_get_value(gpio->left) ^ gpio->polarity);
40	y = (gpio_get_value(gpio->down) ^ gpio->polarity)
41		- (gpio_get_value(gpio->up) ^ gpio->polarity);
42
43	input_report_rel(input, REL_X, x);
44	input_report_rel(input, REL_Y, y);
45	input_sync(input);
46}
47
48static int gpio_mouse_probe(struct platform_device *pdev)
49{
50	struct gpio_mouse_platform_data *pdata = dev_get_platdata(&pdev->dev);
51	struct input_polled_dev *input_poll;
52	struct input_dev *input;
53	int pin, i;
54	int error;
55
56	if (!pdata) {
57		dev_err(&pdev->dev, "no platform data\n");
58		error = -ENXIO;
59		goto out;
60	}
61
62	if (pdata->scan_ms < 0) {
63		dev_err(&pdev->dev, "invalid scan time\n");
64		error = -EINVAL;
65		goto out;
66	}
67
68	for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
69		pin = pdata->pins[i];
70
71		if (pin < 0) {
72
73			if (i <= GPIO_MOUSE_PIN_RIGHT) {
74				/* Mouse direction is required. */
75				dev_err(&pdev->dev,
76					"missing GPIO for directions\n");
77				error = -EINVAL;
78				goto out_free_gpios;
79			}
80
81			if (i == GPIO_MOUSE_PIN_BLEFT)
82				dev_dbg(&pdev->dev, "no left button defined\n");
83
84		} else {
85			error = gpio_request(pin, "gpio_mouse");
86			if (error) {
87				dev_err(&pdev->dev, "fail %d pin (%d idx)\n",
88					pin, i);
89				goto out_free_gpios;
90			}
91
92			gpio_direction_input(pin);
93		}
94	}
95
96	input_poll = input_allocate_polled_device();
97	if (!input_poll) {
98		dev_err(&pdev->dev, "not enough memory for input device\n");
99		error = -ENOMEM;
100		goto out_free_gpios;
101	}
102
103	platform_set_drvdata(pdev, input_poll);
104
105	/* set input-polldev handlers */
106	input_poll->private = pdata;
107	input_poll->poll = gpio_mouse_scan;
108	input_poll->poll_interval = pdata->scan_ms;
109
110	input = input_poll->input;
111	input->name = pdev->name;
112	input->id.bustype = BUS_HOST;
113	input->dev.parent = &pdev->dev;
114
115	input_set_capability(input, EV_REL, REL_X);
116	input_set_capability(input, EV_REL, REL_Y);
117	if (pdata->bleft >= 0)
118		input_set_capability(input, EV_KEY, BTN_LEFT);
119	if (pdata->bmiddle >= 0)
120		input_set_capability(input, EV_KEY, BTN_MIDDLE);
121	if (pdata->bright >= 0)
122		input_set_capability(input, EV_KEY, BTN_RIGHT);
123
124	error = input_register_polled_device(input_poll);
125	if (error) {
126		dev_err(&pdev->dev, "could not register input device\n");
127		goto out_free_polldev;
128	}
129
130	dev_dbg(&pdev->dev, "%d ms scan time, buttons: %s%s%s\n",
131			pdata->scan_ms,
132			pdata->bleft < 0 ? "" : "left ",
133			pdata->bmiddle < 0 ? "" : "middle ",
134			pdata->bright < 0 ? "" : "right");
135
136	return 0;
137
138 out_free_polldev:
139	input_free_polled_device(input_poll);
140
141 out_free_gpios:
142	while (--i >= 0) {
143		pin = pdata->pins[i];
144		if (pin)
145			gpio_free(pin);
146	}
147 out:
148	return error;
149}
150
151static int gpio_mouse_remove(struct platform_device *pdev)
152{
153	struct input_polled_dev *input = platform_get_drvdata(pdev);
154	struct gpio_mouse_platform_data *pdata = input->private;
155	int pin, i;
156
157	input_unregister_polled_device(input);
158	input_free_polled_device(input);
159
160	for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
161		pin = pdata->pins[i];
162		if (pin >= 0)
163			gpio_free(pin);
164	}
165
166	return 0;
167}
168
169static struct platform_driver gpio_mouse_device_driver = {
170	.probe		= gpio_mouse_probe,
171	.remove		= gpio_mouse_remove,
172	.driver		= {
173		.name	= "gpio_mouse",
174	}
175};
176module_platform_driver(gpio_mouse_device_driver);
177
178MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");
179MODULE_DESCRIPTION("GPIO mouse driver");
180MODULE_LICENSE("GPL");
181MODULE_ALIAS("platform:gpio_mouse"); /* work with hotplug and coldplug */
182
183