2 * Driver for buttons on GPIO lines not capable of generating interrupts
4 * Copyright (C) 2007,2008 Gabor Juhos <juhosg at openwrt.org>
6 * This file was based on: /drivers/input/misc/cobalt_btns.c
7 * Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
9 * also was based on: /drivers/input/keyboard/gpio_keys.c
10 * Copyright 2005 Phil Blundell
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
18 #include <linux/init.h>
19 #include <linux/input-polldev.h>
20 #include <linux/ioport.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
24 #include <linux/gpio_buttons.h>
28 #define DRV_NAME "gpio-buttons"
29 #define DRV_VERSION "0.1.0"
30 #define PFX DRV_NAME ": "
32 struct gpio_buttons_dev {
33 struct input_polled_dev *poll_dev;
34 struct gpio_buttons_platform_data *pdata;
37 static void gpio_buttons_poll(struct input_polled_dev *dev)
39 struct gpio_buttons_dev *bdev = dev->private;
40 struct gpio_buttons_platform_data *pdata = bdev->pdata;
41 struct input_dev *input = dev->input;
44 for (i = 0; i < bdev->pdata->nbuttons; i++) {
45 struct gpio_button *button = &pdata->buttons[i];
46 unsigned int type = button->type ?: EV_KEY;
49 state = gpio_get_value(button->gpio) ? 1 : 0;
50 state ^= button->active_low;
55 if (button->count >= button->threshold) {
56 input_event(input, type, button->code, 1);
62 if (button->count == button->threshold) {
63 input_event(input, type, button->code, 0);
69 static int __devinit gpio_buttons_probe(struct platform_device *pdev)
71 struct gpio_buttons_platform_data *pdata = pdev->dev.platform_data;
72 struct gpio_buttons_dev *bdev;
73 struct input_polled_dev *poll_dev;
74 struct input_dev *input;
81 bdev = kzalloc(sizeof(*bdev), GFP_KERNEL);
83 pr_err(DRV_NAME "no memory for device\n");
87 poll_dev = input_allocate_polled_device();
89 pr_err(DRV_NAME "no memory for polled device\n");
94 poll_dev->private = bdev;
95 poll_dev->poll = gpio_buttons_poll;
96 poll_dev->poll_interval = pdata->poll_interval;
98 input = poll_dev->input;
100 input->evbit[0] = BIT_MASK(EV_KEY);
101 input->name = pdev->name;
102 input->phys = "gpio-buttons/input0";
103 input->dev.parent = &pdev->dev;
105 input->id.bustype = BUS_HOST;
106 input->id.vendor = 0x0001;
107 input->id.product = 0x0001;
108 input->id.version = 0x0100;
110 for (i = 0; i < pdata->nbuttons; i++) {
111 struct gpio_button *button = &pdata->buttons[i];
112 unsigned int gpio = button->gpio;
113 unsigned int type = button->type ?: EV_KEY;
115 error = gpio_request(gpio, button->desc ?
116 button->desc : DRV_NAME);
118 pr_err(PFX "unable to claim gpio %u, error %d\n",
123 error = gpio_direction_input(gpio);
125 pr_err(PFX "unable to set direction on gpio %u, "
126 "error %d\n", gpio, error);
130 input_set_capability(input, type, button->code);
134 bdev->poll_dev = poll_dev;
136 platform_set_drvdata(pdev, bdev);
138 error = input_register_polled_device(poll_dev);
140 pr_err(PFX "unable to register polled device, error %d\n",
148 for (i = i - 1; i >= 0; i--)
149 gpio_free(pdata->buttons[i].gpio);
151 input_free_polled_device(poll_dev);
156 platform_set_drvdata(pdev, NULL);
160 static int __devexit gpio_buttons_remove(struct platform_device *pdev)
162 struct gpio_buttons_dev *bdev = platform_get_drvdata(pdev);
163 struct gpio_buttons_platform_data *pdata = bdev->pdata;
166 input_unregister_polled_device(bdev->poll_dev);
168 for (i = 0; i < pdata->nbuttons; i++)
169 gpio_free(pdata->buttons[i].gpio);
171 input_free_polled_device(bdev->poll_dev);
174 platform_set_drvdata(pdev, NULL);
179 static struct platform_driver gpio_buttons_driver = {
180 .probe = gpio_buttons_probe,
181 .remove = __devexit_p(gpio_buttons_remove),
184 .owner = THIS_MODULE,
188 static int __init gpio_buttons_init(void)
190 pr_info(DRV_NAME " driver version " DRV_VERSION "\n");
191 return platform_driver_register(&gpio_buttons_driver);
194 static void __exit gpio_buttons_exit(void)
196 platform_driver_unregister(&gpio_buttons_driver);
199 module_init(gpio_buttons_init);
200 module_exit(gpio_buttons_exit);
202 MODULE_LICENSE("GPL");
203 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
204 MODULE_VERSION(DRV_VERSION);
205 MODULE_DESCRIPTION("Polled buttons driver for CPU GPIOs");