linux/drivers/input/keyboard/gpio_keys.c

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/*
* Driver for keys on GPIO lines capable of generating interrupts.
*
* Copyright 2005 Phil Blundell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/gpio_keys.h>
#include <linux/workqueue.h>
#include <linux/gpio.h>
struct gpio_button_data {
struct gpio_keys_button *button;
struct input_dev *input;
struct timer_list timer;
struct work_struct work;
};
struct gpio_keys_drvdata {
struct input_dev *input;
struct gpio_button_data data[0];
};
static void gpio_keys_report_event(struct gpio_button_data *bdata)
{
struct gpio_keys_button *button = bdata->button;
struct input_dev *input = bdata->input;
unsigned int type = button->type ?: EV_KEY;
int state = (gpio_get_value(button->gpio) ? 1 : 0) ^ button->active_low;
input_event(input, type, button->code, !!state);
input_sync(input);
}
static void gpio_keys_work_func(struct work_struct *work)
{
struct gpio_button_data *bdata =
container_of(work, struct gpio_button_data, work);
gpio_keys_report_event(bdata);
}
static void gpio_keys_timer(unsigned long _data)
{
struct gpio_button_data *data = (struct gpio_button_data *)_data;
schedule_work(&data->work);
}
static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
{
struct gpio_button_data *bdata = dev_id;
struct gpio_keys_button *button = bdata->button;
BUG_ON(irq != gpio_to_irq(button->gpio));
if (button->debounce_interval)
mod_timer(&bdata->timer,
jiffies + msecs_to_jiffies(button->debounce_interval));
else
schedule_work(&bdata->work);
return IRQ_HANDLED;
}
static int __devinit gpio_keys_setup_key(struct device *dev,
struct gpio_button_data *bdata,
struct gpio_keys_button *button)
{
char *desc = button->desc ? button->desc : "gpio_keys";
int irq, error;
setup_timer(&bdata->timer, gpio_keys_timer, (unsigned long)bdata);
INIT_WORK(&bdata->work, gpio_keys_work_func);
error = gpio_request(button->gpio, desc);
if (error < 0) {
dev_err(dev, "failed to request GPIO %d, error %d\n",
button->gpio, error);
goto fail2;
}
error = gpio_direction_input(button->gpio);
if (error < 0) {
dev_err(dev, "failed to configure"
" direction for GPIO %d, error %d\n",
button->gpio, error);
goto fail3;
}
irq = gpio_to_irq(button->gpio);
if (irq < 0) {
error = irq;
dev_err(dev, "Unable to get irq number for GPIO %d, error %d\n",
button->gpio, error);
goto fail3;
}
error = request_irq(irq, gpio_keys_isr,
IRQF_SHARED |
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
desc, bdata);
if (error) {
dev_err(dev, "Unable to claim irq %d; error %d\n",
irq, error);
goto fail3;
}
return 0;
fail3:
gpio_free(button->gpio);
fail2:
return error;
}
static int __devinit gpio_keys_probe(struct platform_device *pdev)
{
struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
struct gpio_keys_drvdata *ddata;
struct device *dev = &pdev->dev;
struct input_dev *input;
int i, error;
int wakeup = 0;
ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
pdata->nbuttons * sizeof(struct gpio_button_data),
GFP_KERNEL);
input = input_allocate_device();
if (!ddata || !input) {
dev_err(dev, "failed to allocate state\n");
error = -ENOMEM;
goto fail1;
}
platform_set_drvdata(pdev, ddata);
input->name = pdev->name;
input->phys = "gpio-keys/input0";
input->dev.parent = &pdev->dev;
input->id.bustype = BUS_HOST;
input->id.vendor = 0x0001;
input->id.product = 0x0001;
input->id.version = 0x0100;
/* Enable auto repeat feature of Linux input subsystem */
if (pdata->rep)
__set_bit(EV_REP, input->evbit);
ddata->input = input;
for (i = 0; i < pdata->nbuttons; i++) {
struct gpio_keys_button *button = &pdata->buttons[i];
struct gpio_button_data *bdata = &ddata->data[i];
unsigned int type = button->type ?: EV_KEY;
bdata->input = input;
bdata->button = button;
error = gpio_keys_setup_key(dev, bdata, button);
if (error)
goto fail2;
if (button->wakeup)
wakeup = 1;
input_set_capability(input, type, button->code);
}
error = input_register_device(input);
if (error) {
dev_err(dev, "Unable to register input device, "
"error: %d\n", error);
goto fail2;
}
/* get current state of buttons */
for (i = 0; i < pdata->nbuttons; i++)
gpio_keys_report_event(&ddata->data[i]);
input_sync(input);
device_init_wakeup(&pdev->dev, wakeup);
return 0;
fail2:
while (--i >= 0) {
free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
if (pdata->buttons[i].debounce_interval)
del_timer_sync(&ddata->data[i].timer);
cancel_work_sync(&ddata->data[i].work);
gpio_free(pdata->buttons[i].gpio);
}
platform_set_drvdata(pdev, NULL);
fail1:
input_free_device(input);
kfree(ddata);
return error;
}
static int __devexit gpio_keys_remove(struct platform_device *pdev)
{
struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
struct input_dev *input = ddata->input;
int i;
device_init_wakeup(&pdev->dev, 0);
for (i = 0; i < pdata->nbuttons; i++) {
int irq = gpio_to_irq(pdata->buttons[i].gpio);
free_irq(irq, &ddata->data[i]);
if (pdata->buttons[i].debounce_interval)
del_timer_sync(&ddata->data[i].timer);
cancel_work_sync(&ddata->data[i].work);
gpio_free(pdata->buttons[i].gpio);
}
input_unregister_device(input);
return 0;
}
#ifdef CONFIG_PM
static int gpio_keys_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
int i;
if (device_may_wakeup(&pdev->dev)) {
for (i = 0; i < pdata->nbuttons; i++) {
struct gpio_keys_button *button = &pdata->buttons[i];
if (button->wakeup) {
int irq = gpio_to_irq(button->gpio);
enable_irq_wake(irq);
}
}
}
return 0;
}
static int gpio_keys_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
int i;
for (i = 0; i < pdata->nbuttons; i++) {
struct gpio_keys_button *button = &pdata->buttons[i];
if (button->wakeup && device_may_wakeup(&pdev->dev)) {
int irq = gpio_to_irq(button->gpio);
disable_irq_wake(irq);
}
gpio_keys_report_event(&ddata->data[i]);
}
input_sync(ddata->input);
return 0;
}
static const struct dev_pm_ops gpio_keys_pm_ops = {
.suspend = gpio_keys_suspend,
.resume = gpio_keys_resume,
};
#endif
static struct platform_driver gpio_keys_device_driver = {
.probe = gpio_keys_probe,
.remove = __devexit_p(gpio_keys_remove),
.driver = {
.name = "gpio-keys",
.owner = THIS_MODULE,
#ifdef CONFIG_PM
.pm = &gpio_keys_pm_ops,
#endif
}
};
static int __init gpio_keys_init(void)
{
return platform_driver_register(&gpio_keys_device_driver);
}
static void __exit gpio_keys_exit(void)
{
platform_driver_unregister(&gpio_keys_device_driver);
}
module_init(gpio_keys_init);
module_exit(gpio_keys_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");
MODULE_ALIAS("platform:gpio-keys");