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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/init.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/input-polldev.h>
15#include <linux/gpio_mouse.h>
16
17#include <asm/gpio.h>
18
19/*
20 * Timer function which is run every scan_ms ms when the device is opened.
21 * The dev input variable is set to the the input_dev pointer.
22 */
23static void gpio_mouse_scan(struct input_polled_dev *dev)
24{
25 struct gpio_mouse_platform_data *gpio = dev->private;
26 struct input_dev *input = dev->input;
27 int x, y;
28
29 if (gpio->bleft >= 0)
30 input_report_key(input, BTN_LEFT,
31 gpio_get_value(gpio->bleft) ^ gpio->polarity);
32 if (gpio->bmiddle >= 0)
33 input_report_key(input, BTN_MIDDLE,
34 gpio_get_value(gpio->bmiddle) ^ gpio->polarity);
35 if (gpio->bright >= 0)
36 input_report_key(input, BTN_RIGHT,
37 gpio_get_value(gpio->bright) ^ gpio->polarity);
38
39 x = (gpio_get_value(gpio->right) ^ gpio->polarity)
40 - (gpio_get_value(gpio->left) ^ gpio->polarity);
41 y = (gpio_get_value(gpio->down) ^ gpio->polarity)
42 - (gpio_get_value(gpio->up) ^ gpio->polarity);
43
44 input_report_rel(input, REL_X, x);
45 input_report_rel(input, REL_Y, y);
46 input_sync(input);
47}
48
49static int __devinit gpio_mouse_probe(struct platform_device *pdev)
50{
51 struct gpio_mouse_platform_data *pdata = pdev->dev.platform_data;
52 struct input_polled_dev *input_poll;
53 struct input_dev *input;
54 int pin, i;
55 int error;
56
57 if (!pdata) {
58 dev_err(&pdev->dev, "no platform data\n");
59 error = -ENXIO;
60 goto out;
61 }
62
63 if (pdata->scan_ms < 0) {
64 dev_err(&pdev->dev, "invalid scan time\n");
65 error = -EINVAL;
66 goto out;
67 }
68
69 for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
70 pin = pdata->pins[i];
71
72 if (pin < 0) {
73
74 if (i <= GPIO_MOUSE_PIN_RIGHT) {
75 /* Mouse direction is required. */
76 dev_err(&pdev->dev,
77 "missing GPIO for directions\n");
78 error = -EINVAL;
79 goto out_free_gpios;
80 }
81
82 if (i == GPIO_MOUSE_PIN_BLEFT)
83 dev_dbg(&pdev->dev, "no left button defined\n");
84
85 } else {
86 error = gpio_request(pin, "gpio_mouse");
87 if (error) {
88 dev_err(&pdev->dev, "fail %d pin (%d idx)\n",
89 pin, i);
90 goto out_free_gpios;
91 }
92
93 gpio_direction_input(pin);
94 }
95 }
96
97 input_poll = input_allocate_polled_device();
98 if (!input_poll) {
99 dev_err(&pdev->dev, "not enough memory for input device\n");
100 error = -ENOMEM;
101 goto out_free_gpios;
102 }
103
104 platform_set_drvdata(pdev, input_poll);
105
106 /* set input-polldev handlers */
107 input_poll->private = pdata;
108 input_poll->poll = gpio_mouse_scan;
109 input_poll->poll_interval = pdata->scan_ms;
110
111 input = input_poll->input;
112 input->name = pdev->name;
113 input->id.bustype = BUS_HOST;
114 input->dev.parent = &pdev->dev;
115
116 input_set_capability(input, EV_REL, REL_X);
117 input_set_capability(input, EV_REL, REL_Y);
118 if (pdata->bleft >= 0)
119 input_set_capability(input, EV_KEY, BTN_LEFT);
120 if (pdata->bmiddle >= 0)
121 input_set_capability(input, EV_KEY, BTN_MIDDLE);
122 if (pdata->bright >= 0)
123 input_set_capability(input, EV_KEY, BTN_RIGHT);
124
125 error = input_register_polled_device(input_poll);
126 if (error) {
127 dev_err(&pdev->dev, "could not register input device\n");
128 goto out_free_polldev;
129 }
130
131 dev_dbg(&pdev->dev, "%d ms scan time, buttons: %s%s%s\n",
132 pdata->scan_ms,
133 pdata->bleft < 0 ? "" : "left ",
134 pdata->bmiddle < 0 ? "" : "middle ",
135 pdata->bright < 0 ? "" : "right");
136
137 return 0;
138
139 out_free_polldev:
140 input_free_polled_device(input_poll);
141 platform_set_drvdata(pdev, NULL);
142
143 out_free_gpios:
144 while (--i >= 0) {
145 pin = pdata->pins[i];
146 if (pin)
147 gpio_free(pin);
148 }
149 out:
150 return error;
151}
152
153static int __devexit gpio_mouse_remove(struct platform_device *pdev)
154{
155 struct input_polled_dev *input = platform_get_drvdata(pdev);
156 struct gpio_mouse_platform_data *pdata = input->private;
157 int pin, i;
158
159 input_unregister_polled_device(input);
160 input_free_polled_device(input);
161
162 for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
163 pin = pdata->pins[i];
164 if (pin >= 0)
165 gpio_free(pin);
166 }
167
168 platform_set_drvdata(pdev, NULL);
169
170 return 0;
171}
172
173static struct platform_driver gpio_mouse_device_driver = {
174 .probe = gpio_mouse_probe,
175 .remove = __devexit_p(gpio_mouse_remove),
176 .driver = {
177 .name = "gpio_mouse",
178 .owner = THIS_MODULE,
179 }
180};
181
182static int __init gpio_mouse_init(void)
183{
184 return platform_driver_register(&gpio_mouse_device_driver);
185}
186module_init(gpio_mouse_init);
187
188static void __exit gpio_mouse_exit(void)
189{
190 platform_driver_unregister(&gpio_mouse_device_driver);
191}
192module_exit(gpio_mouse_exit);
193
194MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");
195MODULE_DESCRIPTION("GPIO mouse driver");
196MODULE_LICENSE("GPL");
197MODULE_ALIAS("platform:gpio_mouse"); /* work with hotplug and coldplug */
198
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for simulating a mouse on GPIO lines.
4 *
5 * Copyright (C) 2007 Atmel Corporation
6 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
7 */
8
9#include <linux/module.h>
10#include <linux/platform_device.h>
11#include <linux/input.h>
12#include <linux/gpio/consumer.h>
13#include <linux/property.h>
14#include <linux/of.h>
15
16/**
17 * struct gpio_mouse
18 * @scan_ms: the scan interval in milliseconds.
19 * @up: GPIO line for up value.
20 * @down: GPIO line for down value.
21 * @left: GPIO line for left value.
22 * @right: GPIO line for right value.
23 * @bleft: GPIO line for left button.
24 * @bmiddle: GPIO line for middle button.
25 * @bright: GPIO line for right button.
26 *
27 * This struct must be added to the platform_device in the board code.
28 * It is used by the gpio_mouse driver to setup GPIO lines and to
29 * calculate mouse movement.
30 */
31struct gpio_mouse {
32 u32 scan_ms;
33 struct gpio_desc *up;
34 struct gpio_desc *down;
35 struct gpio_desc *left;
36 struct gpio_desc *right;
37 struct gpio_desc *bleft;
38 struct gpio_desc *bmiddle;
39 struct gpio_desc *bright;
40};
41
42/*
43 * Timer function which is run every scan_ms ms when the device is opened.
44 * The dev input variable is set to the input_dev pointer.
45 */
46static void gpio_mouse_scan(struct input_dev *input)
47{
48 struct gpio_mouse *gpio = input_get_drvdata(input);
49 int x, y;
50
51 if (gpio->bleft)
52 input_report_key(input, BTN_LEFT,
53 gpiod_get_value(gpio->bleft));
54 if (gpio->bmiddle)
55 input_report_key(input, BTN_MIDDLE,
56 gpiod_get_value(gpio->bmiddle));
57 if (gpio->bright)
58 input_report_key(input, BTN_RIGHT,
59 gpiod_get_value(gpio->bright));
60
61 x = gpiod_get_value(gpio->right) - gpiod_get_value(gpio->left);
62 y = gpiod_get_value(gpio->down) - gpiod_get_value(gpio->up);
63
64 input_report_rel(input, REL_X, x);
65 input_report_rel(input, REL_Y, y);
66 input_sync(input);
67}
68
69static int gpio_mouse_probe(struct platform_device *pdev)
70{
71 struct device *dev = &pdev->dev;
72 struct gpio_mouse *gmouse;
73 struct input_dev *input;
74 int error;
75
76 gmouse = devm_kzalloc(dev, sizeof(*gmouse), GFP_KERNEL);
77 if (!gmouse)
78 return -ENOMEM;
79
80 /* Assign some default scanning time */
81 error = device_property_read_u32(dev, "scan-interval-ms",
82 &gmouse->scan_ms);
83 if (error || gmouse->scan_ms == 0) {
84 dev_warn(dev, "invalid scan time, set to 50 ms\n");
85 gmouse->scan_ms = 50;
86 }
87
88 gmouse->up = devm_gpiod_get(dev, "up", GPIOD_IN);
89 if (IS_ERR(gmouse->up))
90 return PTR_ERR(gmouse->up);
91 gmouse->down = devm_gpiod_get(dev, "down", GPIOD_IN);
92 if (IS_ERR(gmouse->down))
93 return PTR_ERR(gmouse->down);
94 gmouse->left = devm_gpiod_get(dev, "left", GPIOD_IN);
95 if (IS_ERR(gmouse->left))
96 return PTR_ERR(gmouse->left);
97 gmouse->right = devm_gpiod_get(dev, "right", GPIOD_IN);
98 if (IS_ERR(gmouse->right))
99 return PTR_ERR(gmouse->right);
100
101 gmouse->bleft = devm_gpiod_get_optional(dev, "button-left", GPIOD_IN);
102 if (IS_ERR(gmouse->bleft))
103 return PTR_ERR(gmouse->bleft);
104 gmouse->bmiddle = devm_gpiod_get_optional(dev, "button-middle",
105 GPIOD_IN);
106 if (IS_ERR(gmouse->bmiddle))
107 return PTR_ERR(gmouse->bmiddle);
108 gmouse->bright = devm_gpiod_get_optional(dev, "button-right",
109 GPIOD_IN);
110 if (IS_ERR(gmouse->bright))
111 return PTR_ERR(gmouse->bright);
112
113 input = devm_input_allocate_device(dev);
114 if (!input)
115 return -ENOMEM;
116
117 input->name = pdev->name;
118 input->id.bustype = BUS_HOST;
119
120 input_set_drvdata(input, gmouse);
121
122 input_set_capability(input, EV_REL, REL_X);
123 input_set_capability(input, EV_REL, REL_Y);
124 if (gmouse->bleft)
125 input_set_capability(input, EV_KEY, BTN_LEFT);
126 if (gmouse->bmiddle)
127 input_set_capability(input, EV_KEY, BTN_MIDDLE);
128 if (gmouse->bright)
129 input_set_capability(input, EV_KEY, BTN_RIGHT);
130
131 error = input_setup_polling(input, gpio_mouse_scan);
132 if (error)
133 return error;
134
135 input_set_poll_interval(input, gmouse->scan_ms);
136
137 error = input_register_device(input);
138 if (error) {
139 dev_err(dev, "could not register input device\n");
140 return error;
141 }
142
143 dev_dbg(dev, "%d ms scan time, buttons: %s%s%s\n",
144 gmouse->scan_ms,
145 gmouse->bleft ? "" : "left ",
146 gmouse->bmiddle ? "" : "middle ",
147 gmouse->bright ? "" : "right");
148
149 return 0;
150}
151
152static const struct of_device_id gpio_mouse_of_match[] = {
153 { .compatible = "gpio-mouse", },
154 { },
155};
156MODULE_DEVICE_TABLE(of, gpio_mouse_of_match);
157
158static struct platform_driver gpio_mouse_device_driver = {
159 .probe = gpio_mouse_probe,
160 .driver = {
161 .name = "gpio_mouse",
162 .of_match_table = gpio_mouse_of_match,
163 }
164};
165module_platform_driver(gpio_mouse_device_driver);
166
167MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");
168MODULE_DESCRIPTION("GPIO mouse driver");
169MODULE_LICENSE("GPL");
170MODULE_ALIAS("platform:gpio_mouse"); /* work with hotplug and coldplug */