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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 */
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