2 * Driver for keys on GPIO lines capable of generating interrupts.
4 * Copyright 2005 Phil Blundell
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.
11 #include <linux/module.h>
13 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/sched.h>
19 #include <linux/sysctl.h>
20 #include <linux/proc_fs.h>
21 #include <linux/delay.h>
22 #include <linux/platform_device.h>
23 #include <linux/input.h>
24 #include <linux/gpio_keys.h>
25 #include <linux/workqueue.h>
26 #include <linux/gpio.h>
28 struct gpio_button_data {
29 struct gpio_keys_button *button;
30 struct input_dev *input;
31 struct timer_list timer;
32 struct work_struct work;
35 struct gpio_keys_drvdata {
36 struct input_dev *input;
37 struct gpio_button_data data[0];
40 static void gpio_keys_report_event(struct work_struct *work)
42 struct gpio_button_data *bdata =
43 container_of(work, struct gpio_button_data, work);
44 struct gpio_keys_button *button = bdata->button;
45 struct input_dev *input = bdata->input;
46 unsigned int type = button->type ?: EV_KEY;
47 int state = (gpio_get_value(button->gpio) ? 1 : 0) ^ button->active_low;
49 input_event(input, type, button->code, !!state);
53 static void gpio_keys_timer(unsigned long _data)
55 struct gpio_button_data *data = (struct gpio_button_data *)_data;
57 schedule_work(&data->work);
60 static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
62 struct gpio_button_data *bdata = dev_id;
63 struct gpio_keys_button *button = bdata->button;
65 BUG_ON(irq != gpio_to_irq(button->gpio));
67 if (button->debounce_interval)
68 mod_timer(&bdata->timer,
69 jiffies + msecs_to_jiffies(button->debounce_interval));
71 schedule_work(&bdata->work);
76 static int __devinit gpio_keys_setup_key(struct device *dev,
77 struct gpio_button_data *bdata,
78 struct gpio_keys_button *button)
80 char *desc = button->desc ? button->desc : "gpio_keys";
83 setup_timer(&bdata->timer, gpio_keys_timer, (unsigned long)bdata);
84 INIT_WORK(&bdata->work, gpio_keys_report_event);
86 error = gpio_request(button->gpio, desc);
88 dev_err(dev, "failed to request GPIO %d, error %d\n",
93 error = gpio_direction_input(button->gpio);
95 dev_err(dev, "failed to configure"
96 " direction for GPIO %d, error %d\n",
101 irq = gpio_to_irq(button->gpio);
104 dev_err(dev, "Unable to get irq number for GPIO %d, error %d\n",
105 button->gpio, error);
109 error = request_irq(irq, gpio_keys_isr,
111 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
114 dev_err(dev, "Unable to claim irq %d; error %d\n",
122 gpio_free(button->gpio);
127 static int __devinit gpio_keys_probe(struct platform_device *pdev)
129 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
130 struct gpio_keys_drvdata *ddata;
131 struct device *dev = &pdev->dev;
132 struct input_dev *input;
136 ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
137 pdata->nbuttons * sizeof(struct gpio_button_data),
139 input = input_allocate_device();
140 if (!ddata || !input) {
141 dev_err(dev, "failed to allocate state\n");
146 platform_set_drvdata(pdev, ddata);
148 input->name = pdev->name;
149 input->phys = "gpio-keys/input0";
150 input->dev.parent = &pdev->dev;
152 input->id.bustype = BUS_HOST;
153 input->id.vendor = 0x0001;
154 input->id.product = 0x0001;
155 input->id.version = 0x0100;
157 /* Enable auto repeat feature of Linux input subsystem */
159 __set_bit(EV_REP, input->evbit);
161 ddata->input = input;
163 for (i = 0; i < pdata->nbuttons; i++) {
164 struct gpio_keys_button *button = &pdata->buttons[i];
165 struct gpio_button_data *bdata = &ddata->data[i];
166 unsigned int type = button->type ?: EV_KEY;
168 bdata->input = input;
169 bdata->button = button;
171 error = gpio_keys_setup_key(dev, bdata, button);
178 input_set_capability(input, type, button->code);
181 error = input_register_device(input);
183 dev_err(dev, "Unable to register input device, "
184 "error: %d\n", error);
188 device_init_wakeup(&pdev->dev, wakeup);
194 free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
195 if (pdata->buttons[i].debounce_interval)
196 del_timer_sync(&ddata->data[i].timer);
197 cancel_work_sync(&ddata->data[i].work);
198 gpio_free(pdata->buttons[i].gpio);
201 platform_set_drvdata(pdev, NULL);
203 input_free_device(input);
209 static int __devexit gpio_keys_remove(struct platform_device *pdev)
211 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
212 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
213 struct input_dev *input = ddata->input;
216 device_init_wakeup(&pdev->dev, 0);
218 for (i = 0; i < pdata->nbuttons; i++) {
219 int irq = gpio_to_irq(pdata->buttons[i].gpio);
220 free_irq(irq, &ddata->data[i]);
221 if (pdata->buttons[i].debounce_interval)
222 del_timer_sync(&ddata->data[i].timer);
223 cancel_work_sync(&ddata->data[i].work);
224 gpio_free(pdata->buttons[i].gpio);
227 input_unregister_device(input);
234 static int gpio_keys_suspend(struct device *dev)
236 struct platform_device *pdev = to_platform_device(dev);
237 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
240 if (device_may_wakeup(&pdev->dev)) {
241 for (i = 0; i < pdata->nbuttons; i++) {
242 struct gpio_keys_button *button = &pdata->buttons[i];
243 if (button->wakeup) {
244 int irq = gpio_to_irq(button->gpio);
245 enable_irq_wake(irq);
253 static int gpio_keys_resume(struct device *dev)
255 struct platform_device *pdev = to_platform_device(dev);
256 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
259 if (device_may_wakeup(&pdev->dev)) {
260 for (i = 0; i < pdata->nbuttons; i++) {
261 struct gpio_keys_button *button = &pdata->buttons[i];
262 if (button->wakeup) {
263 int irq = gpio_to_irq(button->gpio);
264 disable_irq_wake(irq);
272 static const struct dev_pm_ops gpio_keys_pm_ops = {
273 .suspend = gpio_keys_suspend,
274 .resume = gpio_keys_resume,
278 static struct platform_driver gpio_keys_device_driver = {
279 .probe = gpio_keys_probe,
280 .remove = __devexit_p(gpio_keys_remove),
283 .owner = THIS_MODULE,
285 .pm = &gpio_keys_pm_ops,
290 static int __init gpio_keys_init(void)
292 return platform_driver_register(&gpio_keys_device_driver);
295 static void __exit gpio_keys_exit(void)
297 platform_driver_unregister(&gpio_keys_device_driver);
300 module_init(gpio_keys_init);
301 module_exit(gpio_keys_exit);
303 MODULE_LICENSE("GPL");
304 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
305 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");
306 MODULE_ALIAS("platform:gpio-keys");