linux/drivers/input/keyboard/gpio_keys.c
Dmitry Torokhov e324ce61ef Input: gpio_keys - defer probing if GPIO probing is deferred
If of_get_gpio_flags() returns an error (as in case when GPIO probe is
deferred) the driver would attempt to claim invalid GPIO. It should
propagate the error code up the stack instead so that the probe either
fails or will be retried later (in case of -EPROBE_DEFER).

Cc: stable@vger.kernel.org
Reported-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2012-12-24 09:51:30 -08:00

886 lines
21 KiB
C

/*
* Driver for keys on GPIO lines capable of generating interrupts.
*
* Copyright 2005 Phil Blundell
* Copyright 2010, 2011 David Jander <david@protonic.nl>
*
* 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/slab.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>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/spinlock.h>
struct gpio_button_data {
const struct gpio_keys_button *button;
struct input_dev *input;
struct timer_list timer;
struct work_struct work;
unsigned int timer_debounce; /* in msecs */
unsigned int irq;
spinlock_t lock;
bool disabled;
bool key_pressed;
};
struct gpio_keys_drvdata {
const struct gpio_keys_platform_data *pdata;
struct input_dev *input;
struct mutex disable_lock;
struct gpio_button_data data[0];
};
/*
* SYSFS interface for enabling/disabling keys and switches:
*
* There are 4 attributes under /sys/devices/platform/gpio-keys/
* keys [ro] - bitmap of keys (EV_KEY) which can be
* disabled
* switches [ro] - bitmap of switches (EV_SW) which can be
* disabled
* disabled_keys [rw] - bitmap of keys currently disabled
* disabled_switches [rw] - bitmap of switches currently disabled
*
* Userland can change these values and hence disable event generation
* for each key (or switch). Disabling a key means its interrupt line
* is disabled.
*
* For example, if we have following switches set up as gpio-keys:
* SW_DOCK = 5
* SW_CAMERA_LENS_COVER = 9
* SW_KEYPAD_SLIDE = 10
* SW_FRONT_PROXIMITY = 11
* This is read from switches:
* 11-9,5
* Next we want to disable proximity (11) and dock (5), we write:
* 11,5
* to file disabled_switches. Now proximity and dock IRQs are disabled.
* This can be verified by reading the file disabled_switches:
* 11,5
* If we now want to enable proximity (11) switch we write:
* 5
* to disabled_switches.
*
* We can disable only those keys which don't allow sharing the irq.
*/
/**
* get_n_events_by_type() - returns maximum number of events per @type
* @type: type of button (%EV_KEY, %EV_SW)
*
* Return value of this function can be used to allocate bitmap
* large enough to hold all bits for given type.
*/
static inline int get_n_events_by_type(int type)
{
BUG_ON(type != EV_SW && type != EV_KEY);
return (type == EV_KEY) ? KEY_CNT : SW_CNT;
}
/**
* gpio_keys_disable_button() - disables given GPIO button
* @bdata: button data for button to be disabled
*
* Disables button pointed by @bdata. This is done by masking
* IRQ line. After this function is called, button won't generate
* input events anymore. Note that one can only disable buttons
* that don't share IRQs.
*
* Make sure that @bdata->disable_lock is locked when entering
* this function to avoid races when concurrent threads are
* disabling buttons at the same time.
*/
static void gpio_keys_disable_button(struct gpio_button_data *bdata)
{
if (!bdata->disabled) {
/*
* Disable IRQ and possible debouncing timer.
*/
disable_irq(bdata->irq);
if (bdata->timer_debounce)
del_timer_sync(&bdata->timer);
bdata->disabled = true;
}
}
/**
* gpio_keys_enable_button() - enables given GPIO button
* @bdata: button data for button to be disabled
*
* Enables given button pointed by @bdata.
*
* Make sure that @bdata->disable_lock is locked when entering
* this function to avoid races with concurrent threads trying
* to enable the same button at the same time.
*/
static void gpio_keys_enable_button(struct gpio_button_data *bdata)
{
if (bdata->disabled) {
enable_irq(bdata->irq);
bdata->disabled = false;
}
}
/**
* gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
* @ddata: pointer to drvdata
* @buf: buffer where stringified bitmap is written
* @type: button type (%EV_KEY, %EV_SW)
* @only_disabled: does caller want only those buttons that are
* currently disabled or all buttons that can be
* disabled
*
* This function writes buttons that can be disabled to @buf. If
* @only_disabled is true, then @buf contains only those buttons
* that are currently disabled. Returns 0 on success or negative
* errno on failure.
*/
static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
char *buf, unsigned int type,
bool only_disabled)
{
int n_events = get_n_events_by_type(type);
unsigned long *bits;
ssize_t ret;
int i;
bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
if (!bits)
return -ENOMEM;
for (i = 0; i < ddata->pdata->nbuttons; i++) {
struct gpio_button_data *bdata = &ddata->data[i];
if (bdata->button->type != type)
continue;
if (only_disabled && !bdata->disabled)
continue;
__set_bit(bdata->button->code, bits);
}
ret = bitmap_scnlistprintf(buf, PAGE_SIZE - 2, bits, n_events);
buf[ret++] = '\n';
buf[ret] = '\0';
kfree(bits);
return ret;
}
/**
* gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
* @ddata: pointer to drvdata
* @buf: buffer from userspace that contains stringified bitmap
* @type: button type (%EV_KEY, %EV_SW)
*
* This function parses stringified bitmap from @buf and disables/enables
* GPIO buttons accordingly. Returns 0 on success and negative error
* on failure.
*/
static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
const char *buf, unsigned int type)
{
int n_events = get_n_events_by_type(type);
unsigned long *bits;
ssize_t error;
int i;
bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
if (!bits)
return -ENOMEM;
error = bitmap_parselist(buf, bits, n_events);
if (error)
goto out;
/* First validate */
for (i = 0; i < ddata->pdata->nbuttons; i++) {
struct gpio_button_data *bdata = &ddata->data[i];
if (bdata->button->type != type)
continue;
if (test_bit(bdata->button->code, bits) &&
!bdata->button->can_disable) {
error = -EINVAL;
goto out;
}
}
mutex_lock(&ddata->disable_lock);
for (i = 0; i < ddata->pdata->nbuttons; i++) {
struct gpio_button_data *bdata = &ddata->data[i];
if (bdata->button->type != type)
continue;
if (test_bit(bdata->button->code, bits))
gpio_keys_disable_button(bdata);
else
gpio_keys_enable_button(bdata);
}
mutex_unlock(&ddata->disable_lock);
out:
kfree(bits);
return error;
}
#define ATTR_SHOW_FN(name, type, only_disabled) \
static ssize_t gpio_keys_show_##name(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct platform_device *pdev = to_platform_device(dev); \
struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
\
return gpio_keys_attr_show_helper(ddata, buf, \
type, only_disabled); \
}
ATTR_SHOW_FN(keys, EV_KEY, false);
ATTR_SHOW_FN(switches, EV_SW, false);
ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
ATTR_SHOW_FN(disabled_switches, EV_SW, true);
/*
* ATTRIBUTES:
*
* /sys/devices/platform/gpio-keys/keys [ro]
* /sys/devices/platform/gpio-keys/switches [ro]
*/
static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
#define ATTR_STORE_FN(name, type) \
static ssize_t gpio_keys_store_##name(struct device *dev, \
struct device_attribute *attr, \
const char *buf, \
size_t count) \
{ \
struct platform_device *pdev = to_platform_device(dev); \
struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
ssize_t error; \
\
error = gpio_keys_attr_store_helper(ddata, buf, type); \
if (error) \
return error; \
\
return count; \
}
ATTR_STORE_FN(disabled_keys, EV_KEY);
ATTR_STORE_FN(disabled_switches, EV_SW);
/*
* ATTRIBUTES:
*
* /sys/devices/platform/gpio-keys/disabled_keys [rw]
* /sys/devices/platform/gpio-keys/disables_switches [rw]
*/
static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
gpio_keys_show_disabled_keys,
gpio_keys_store_disabled_keys);
static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
gpio_keys_show_disabled_switches,
gpio_keys_store_disabled_switches);
static struct attribute *gpio_keys_attrs[] = {
&dev_attr_keys.attr,
&dev_attr_switches.attr,
&dev_attr_disabled_keys.attr,
&dev_attr_disabled_switches.attr,
NULL,
};
static struct attribute_group gpio_keys_attr_group = {
.attrs = gpio_keys_attrs,
};
static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
{
const 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_cansleep(button->gpio) ? 1 : 0) ^ button->active_low;
if (type == EV_ABS) {
if (state)
input_event(input, type, button->code, button->value);
} else {
input_event(input, type, button->code, !!state);
}
input_sync(input);
}
static void gpio_keys_gpio_work_func(struct work_struct *work)
{
struct gpio_button_data *bdata =
container_of(work, struct gpio_button_data, work);
gpio_keys_gpio_report_event(bdata);
if (bdata->button->wakeup)
pm_relax(bdata->input->dev.parent);
}
static void gpio_keys_gpio_timer(unsigned long _data)
{
struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
schedule_work(&bdata->work);
}
static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
{
struct gpio_button_data *bdata = dev_id;
BUG_ON(irq != bdata->irq);
if (bdata->button->wakeup)
pm_stay_awake(bdata->input->dev.parent);
if (bdata->timer_debounce)
mod_timer(&bdata->timer,
jiffies + msecs_to_jiffies(bdata->timer_debounce));
else
schedule_work(&bdata->work);
return IRQ_HANDLED;
}
static void gpio_keys_irq_timer(unsigned long _data)
{
struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
struct input_dev *input = bdata->input;
unsigned long flags;
spin_lock_irqsave(&bdata->lock, flags);
if (bdata->key_pressed) {
input_event(input, EV_KEY, bdata->button->code, 0);
input_sync(input);
bdata->key_pressed = false;
}
spin_unlock_irqrestore(&bdata->lock, flags);
}
static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
{
struct gpio_button_data *bdata = dev_id;
const struct gpio_keys_button *button = bdata->button;
struct input_dev *input = bdata->input;
unsigned long flags;
BUG_ON(irq != bdata->irq);
spin_lock_irqsave(&bdata->lock, flags);
if (!bdata->key_pressed) {
if (bdata->button->wakeup)
pm_wakeup_event(bdata->input->dev.parent, 0);
input_event(input, EV_KEY, button->code, 1);
input_sync(input);
if (!bdata->timer_debounce) {
input_event(input, EV_KEY, button->code, 0);
input_sync(input);
goto out;
}
bdata->key_pressed = true;
}
if (bdata->timer_debounce)
mod_timer(&bdata->timer,
jiffies + msecs_to_jiffies(bdata->timer_debounce));
out:
spin_unlock_irqrestore(&bdata->lock, flags);
return IRQ_HANDLED;
}
static int gpio_keys_setup_key(struct platform_device *pdev,
struct input_dev *input,
struct gpio_button_data *bdata,
const struct gpio_keys_button *button)
{
const char *desc = button->desc ? button->desc : "gpio_keys";
struct device *dev = &pdev->dev;
irq_handler_t isr;
unsigned long irqflags;
int irq, error;
bdata->input = input;
bdata->button = button;
spin_lock_init(&bdata->lock);
if (gpio_is_valid(button->gpio)) {
error = gpio_request_one(button->gpio, GPIOF_IN, desc);
if (error < 0) {
dev_err(dev, "Failed to request GPIO %d, error %d\n",
button->gpio, error);
return error;
}
if (button->debounce_interval) {
error = gpio_set_debounce(button->gpio,
button->debounce_interval * 1000);
/* use timer if gpiolib doesn't provide debounce */
if (error < 0)
bdata->timer_debounce =
button->debounce_interval;
}
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 fail;
}
bdata->irq = irq;
INIT_WORK(&bdata->work, gpio_keys_gpio_work_func);
setup_timer(&bdata->timer,
gpio_keys_gpio_timer, (unsigned long)bdata);
isr = gpio_keys_gpio_isr;
irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
} else {
if (!button->irq) {
dev_err(dev, "No IRQ specified\n");
return -EINVAL;
}
bdata->irq = button->irq;
if (button->type && button->type != EV_KEY) {
dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
return -EINVAL;
}
bdata->timer_debounce = button->debounce_interval;
setup_timer(&bdata->timer,
gpio_keys_irq_timer, (unsigned long)bdata);
isr = gpio_keys_irq_isr;
irqflags = 0;
}
input_set_capability(input, button->type ?: EV_KEY, button->code);
/*
* If platform has specified that the button can be disabled,
* we don't want it to share the interrupt line.
*/
if (!button->can_disable)
irqflags |= IRQF_SHARED;
error = request_any_context_irq(bdata->irq, isr, irqflags, desc, bdata);
if (error < 0) {
dev_err(dev, "Unable to claim irq %d; error %d\n",
bdata->irq, error);
goto fail;
}
return 0;
fail:
if (gpio_is_valid(button->gpio))
gpio_free(button->gpio);
return error;
}
static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
{
struct input_dev *input = ddata->input;
int i;
for (i = 0; i < ddata->pdata->nbuttons; i++) {
struct gpio_button_data *bdata = &ddata->data[i];
if (gpio_is_valid(bdata->button->gpio))
gpio_keys_gpio_report_event(bdata);
}
input_sync(input);
}
static int gpio_keys_open(struct input_dev *input)
{
struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
const struct gpio_keys_platform_data *pdata = ddata->pdata;
int error;
if (pdata->enable) {
error = pdata->enable(input->dev.parent);
if (error)
return error;
}
/* Report current state of buttons that are connected to GPIOs */
gpio_keys_report_state(ddata);
return 0;
}
static void gpio_keys_close(struct input_dev *input)
{
struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
const struct gpio_keys_platform_data *pdata = ddata->pdata;
if (pdata->disable)
pdata->disable(input->dev.parent);
}
/*
* Handlers for alternative sources of platform_data
*/
#ifdef CONFIG_OF
/*
* Translate OpenFirmware node properties into platform_data
*/
static struct gpio_keys_platform_data *
gpio_keys_get_devtree_pdata(struct device *dev)
{
struct device_node *node, *pp;
struct gpio_keys_platform_data *pdata;
struct gpio_keys_button *button;
int error;
int nbuttons;
int i;
node = dev->of_node;
if (!node) {
error = -ENODEV;
goto err_out;
}
nbuttons = of_get_child_count(node);
if (nbuttons == 0) {
error = -ENODEV;
goto err_out;
}
pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
GFP_KERNEL);
if (!pdata) {
error = -ENOMEM;
goto err_out;
}
pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
pdata->nbuttons = nbuttons;
pdata->rep = !!of_get_property(node, "autorepeat", NULL);
i = 0;
for_each_child_of_node(node, pp) {
int gpio;
enum of_gpio_flags flags;
if (!of_find_property(pp, "gpios", NULL)) {
pdata->nbuttons--;
dev_warn(dev, "Found button without gpios\n");
continue;
}
gpio = of_get_gpio_flags(pp, 0, &flags);
if (gpio < 0) {
error = gpio;
if (error != -EPROBE_DEFER)
dev_err(dev,
"Failed to get gpio flags, error: %d\n",
error);
goto err_free_pdata;
}
button = &pdata->buttons[i++];
button->gpio = gpio;
button->active_low = flags & OF_GPIO_ACTIVE_LOW;
if (of_property_read_u32(pp, "linux,code", &button->code)) {
dev_err(dev, "Button without keycode: 0x%x\n",
button->gpio);
error = -EINVAL;
goto err_free_pdata;
}
button->desc = of_get_property(pp, "label", NULL);
if (of_property_read_u32(pp, "linux,input-type", &button->type))
button->type = EV_KEY;
button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
if (of_property_read_u32(pp, "debounce-interval",
&button->debounce_interval))
button->debounce_interval = 5;
}
if (pdata->nbuttons == 0) {
error = -EINVAL;
goto err_free_pdata;
}
return pdata;
err_free_pdata:
kfree(pdata);
err_out:
return ERR_PTR(error);
}
static struct of_device_id gpio_keys_of_match[] = {
{ .compatible = "gpio-keys", },
{ },
};
MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
#else
static inline struct gpio_keys_platform_data *
gpio_keys_get_devtree_pdata(struct device *dev)
{
return ERR_PTR(-ENODEV);
}
#endif
static void gpio_remove_key(struct gpio_button_data *bdata)
{
free_irq(bdata->irq, bdata);
if (bdata->timer_debounce)
del_timer_sync(&bdata->timer);
cancel_work_sync(&bdata->work);
if (gpio_is_valid(bdata->button->gpio))
gpio_free(bdata->button->gpio);
}
static int gpio_keys_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
struct gpio_keys_drvdata *ddata;
struct input_dev *input;
int i, error;
int wakeup = 0;
if (!pdata) {
pdata = gpio_keys_get_devtree_pdata(dev);
if (IS_ERR(pdata))
return PTR_ERR(pdata);
}
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;
}
ddata->pdata = pdata;
ddata->input = input;
mutex_init(&ddata->disable_lock);
platform_set_drvdata(pdev, ddata);
input_set_drvdata(input, ddata);
input->name = pdata->name ? : pdev->name;
input->phys = "gpio-keys/input0";
input->dev.parent = &pdev->dev;
input->open = gpio_keys_open;
input->close = gpio_keys_close;
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);
for (i = 0; i < pdata->nbuttons; i++) {
const struct gpio_keys_button *button = &pdata->buttons[i];
struct gpio_button_data *bdata = &ddata->data[i];
error = gpio_keys_setup_key(pdev, input, bdata, button);
if (error)
goto fail2;
if (button->wakeup)
wakeup = 1;
}
error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
if (error) {
dev_err(dev, "Unable to export keys/switches, error: %d\n",
error);
goto fail2;
}
error = input_register_device(input);
if (error) {
dev_err(dev, "Unable to register input device, error: %d\n",
error);
goto fail3;
}
device_init_wakeup(&pdev->dev, wakeup);
return 0;
fail3:
sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
fail2:
while (--i >= 0)
gpio_remove_key(&ddata->data[i]);
platform_set_drvdata(pdev, NULL);
fail1:
input_free_device(input);
kfree(ddata);
/* If we have no platform data, we allocated pdata dynamically. */
if (!dev_get_platdata(&pdev->dev))
kfree(pdata);
return error;
}
static int gpio_keys_remove(struct platform_device *pdev)
{
struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
struct input_dev *input = ddata->input;
int i;
sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
device_init_wakeup(&pdev->dev, 0);
for (i = 0; i < ddata->pdata->nbuttons; i++)
gpio_remove_key(&ddata->data[i]);
input_unregister_device(input);
/* If we have no platform data, we allocated pdata dynamically. */
if (!dev_get_platdata(&pdev->dev))
kfree(ddata->pdata);
kfree(ddata);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int gpio_keys_suspend(struct device *dev)
{
struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
struct input_dev *input = ddata->input;
int i;
if (device_may_wakeup(dev)) {
for (i = 0; i < ddata->pdata->nbuttons; i++) {
struct gpio_button_data *bdata = &ddata->data[i];
if (bdata->button->wakeup)
enable_irq_wake(bdata->irq);
}
} else {
mutex_lock(&input->mutex);
if (input->users)
gpio_keys_close(input);
mutex_unlock(&input->mutex);
}
return 0;
}
static int gpio_keys_resume(struct device *dev)
{
struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
struct input_dev *input = ddata->input;
int error = 0;
int i;
if (device_may_wakeup(dev)) {
for (i = 0; i < ddata->pdata->nbuttons; i++) {
struct gpio_button_data *bdata = &ddata->data[i];
if (bdata->button->wakeup)
disable_irq_wake(bdata->irq);
}
} else {
mutex_lock(&input->mutex);
if (input->users)
error = gpio_keys_open(input);
mutex_unlock(&input->mutex);
}
if (error)
return error;
gpio_keys_report_state(ddata);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
static struct platform_driver gpio_keys_device_driver = {
.probe = gpio_keys_probe,
.remove = gpio_keys_remove,
.driver = {
.name = "gpio-keys",
.owner = THIS_MODULE,
.pm = &gpio_keys_pm_ops,
.of_match_table = of_match_ptr(gpio_keys_of_match),
}
};
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);
}
late_initcall(gpio_keys_init);
module_exit(gpio_keys_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
MODULE_DESCRIPTION("Keyboard driver for GPIOs");
MODULE_ALIAS("platform:gpio-keys");