[mirror_ubuntu-jammy-kernel.git] / drivers / input / keyboard / gpio_keys.c

/*
 * 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/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>

struct gpio_button_data {
	struct gpio_keys_button *button;
	struct input_dev *input;
	struct timer_list timer;
	struct work_struct work;
	int timer_debounce;	/* in msecs */
	bool disabled;
};

struct gpio_keys_drvdata {
	struct input_dev *input;
	struct mutex disable_lock;
	unsigned int n_buttons;
	int (*enable)(struct device *dev);
	void (*disable)(struct device *dev);
	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(gpio_to_irq(bdata->button->gpio));
		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(gpio_to_irq(bdata->button->gpio));
		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->n_buttons; 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 accordinly. 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->n_buttons; 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->n_buttons; 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_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_cansleep(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 (bdata->timer_debounce)
		mod_timer(&bdata->timer,
			jiffies + msecs_to_jiffies(bdata->timer_debounce));
	else
		schedule_work(&bdata->work);

	return IRQ_HANDLED;
}

static int __devinit gpio_keys_setup_key(struct platform_device *pdev,
					 struct gpio_button_data *bdata,
					 struct gpio_keys_button *button)
{
	char *desc = button->desc ? button->desc : "gpio_keys";
	struct device *dev = &pdev->dev;
	unsigned long irqflags;
	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;
	}

	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 fail3;
	}

	irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
	/*
	 * 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(irq, gpio_keys_isr, irqflags, desc, bdata);
	if (error < 0) {
		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 gpio_keys_open(struct input_dev *input)
{
	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);

	return ddata->enable ? ddata->enable(input->dev.parent) : 0;
}

static void gpio_keys_close(struct input_dev *input)
{
	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);

	if (ddata->disable)
		ddata->disable(input->dev.parent);
}

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;
	}

	ddata->input = input;
	ddata->n_buttons = pdata->nbuttons;
	ddata->enable = pdata->enable;
	ddata->disable = pdata->disable;
	mutex_init(&ddata->disable_lock);

	platform_set_drvdata(pdev, ddata);
	input_set_drvdata(input, ddata);

	input->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++) {
		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(pdev, bdata, button);
		if (error)
			goto fail2;

		if (button->wakeup)
			wakeup = 1;

		input_set_capability(input, type, button->code);
	}

	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;
	}

	/* 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;

 fail3:
	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
 fail2:
	while (--i >= 0) {
		free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
		if (ddata->data[i].timer_debounce)
			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;

	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);

	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 (ddata->data[i].timer_debounce)
			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");
Commit	Line	Data
78a56aab PB	1	/*
	2	* Driver for keys on GPIO lines capable of generating interrupts.
	3	*
	4	* Copyright 2005 Phil Blundell
	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>
78a56aab PB	12
	13	#include <linux/init.h>
	14	#include <linux/fs.h>
	15	#include <linux/interrupt.h>
	16	#include <linux/irq.h>
	17	#include <linux/sched.h>
	18	#include <linux/pm.h>
5a0e3ad6	19	#include <linux/slab.h>
78a56aab PB	20	#include <linux/sysctl.h>
	21	#include <linux/proc_fs.h>
	22	#include <linux/delay.h>
	23	#include <linux/platform_device.h>
	24	#include <linux/input.h>
49015bee	25	#include <linux/gpio_keys.h>
da0d03fe	26	#include <linux/workqueue.h>
111bc59c	27	#include <linux/gpio.h>
78a56aab	28
a33466e3 DB	29	struct gpio_button_data {
	30	struct gpio_keys_button *button;
	31	struct input_dev *input;
ca865a77	32	struct timer_list timer;
da0d03fe	33	struct work_struct work;
28ed684f	34	int timer_debounce; /* in msecs */
9e3af04f	35	bool disabled;
a33466e3 DB	36	};
	37
	38	struct gpio_keys_drvdata {
	39	struct input_dev *input;
9e3af04f MW	40	struct mutex disable_lock;
9e3af04f MW	41	unsigned int n_buttons;
173bdd74 S	42	int (enable)(struct device dev);
173bdd74 S	43	void (disable)(struct device dev);
a33466e3 DB	44	struct gpio_button_data data[0];
	45	};
	46
9e3af04f MW	47	/*
	48	* SYSFS interface for enabling/disabling keys and switches:
	49	*
	50	* There are 4 attributes under /sys/devices/platform/gpio-keys/
	51	* keys [ro] - bitmap of keys (EV_KEY) which can be
	52	* disabled
	53	* switches [ro] - bitmap of switches (EV_SW) which can be
	54	* disabled
	55	* disabled_keys [rw] - bitmap of keys currently disabled
	56	* disabled_switches [rw] - bitmap of switches currently disabled
	57	*
	58	* Userland can change these values and hence disable event generation
	59	* for each key (or switch). Disabling a key means its interrupt line
	60	* is disabled.
	61	*
	62	* For example, if we have following switches set up as gpio-keys:
	63	* SW_DOCK = 5
	64	* SW_CAMERA_LENS_COVER = 9
	65	* SW_KEYPAD_SLIDE = 10
	66	* SW_FRONT_PROXIMITY = 11
	67	* This is read from switches:
	68	* 11-9,5
	69	* Next we want to disable proximity (11) and dock (5), we write:
	70	* 11,5
	71	* to file disabled_switches. Now proximity and dock IRQs are disabled.
	72	* This can be verified by reading the file disabled_switches:
	73	* 11,5
	74	* If we now want to enable proximity (11) switch we write:
	75	* 5
	76	* to disabled_switches.
	77	*
	78	* We can disable only those keys which don't allow sharing the irq.
	79	*/
	80
	81	/**
	82	* get_n_events_by_type() - returns maximum number of events per @type
	83	* @type: type of button (%EV_KEY, %EV_SW)
	84	*
	85	* Return value of this function can be used to allocate bitmap
	86	* large enough to hold all bits for given type.
	87	*/
	88	static inline int get_n_events_by_type(int type)
	89	{
	90	BUG_ON(type != EV_SW && type != EV_KEY);
	91
	92	return (type == EV_KEY) ? KEY_CNT : SW_CNT;
	93	}
	94
	95	/**
	96	* gpio_keys_disable_button() - disables given GPIO button
	97	* @bdata: button data for button to be disabled
	98	*
	99	* Disables button pointed by @bdata. This is done by masking
	100	* IRQ line. After this function is called, button won't generate
	101	* input events anymore. Note that one can only disable buttons
	102	* that don't share IRQs.
	103	*
	104	* Make sure that @bdata->disable_lock is locked when entering
	105	* this function to avoid races when concurrent threads are
	106	* disabling buttons at the same time.
	107	*/
	108	static void gpio_keys_disable_button(struct gpio_button_data *bdata)
	109	{
	110	if (!bdata->disabled) {
111	/*
112	* Disable IRQ and possible debouncing timer.
113	*/
114	disable_irq(gpio_to_irq(bdata->button->gpio));
28ed684f	115	if (bdata->timer_debounce)
9e3af04f MW	116	del_timer_sync(&bdata->timer);
	117
	118	bdata->disabled = true;
	119	}
	120	}
	121
	122	/**
	123	* gpio_keys_enable_button() - enables given GPIO button
	124	* @bdata: button data for button to be disabled
	125	*
	126	* Enables given button pointed by @bdata.
	127	*
	128	* Make sure that @bdata->disable_lock is locked when entering
	129	* this function to avoid races with concurrent threads trying
	130	* to enable the same button at the same time.
	131	*/
	132	static void gpio_keys_enable_button(struct gpio_button_data *bdata)
	133	{
	134	if (bdata->disabled) {
	135	enable_irq(gpio_to_irq(bdata->button->gpio));
	136	bdata->disabled = false;
	137	}
	138	}
	139
	140	/**
	141	* gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
	142	* @ddata: pointer to drvdata
	143	* @buf: buffer where stringified bitmap is written
	144	* @type: button type (%EV_KEY, %EV_SW)
	145	* @only_disabled: does caller want only those buttons that are
	146	* currently disabled or all buttons that can be
	147	* disabled
	148	*
	149	* This function writes buttons that can be disabled to @buf. If
	150	* @only_disabled is true, then @buf contains only those buttons
	151	* that are currently disabled. Returns 0 on success or negative
	152	* errno on failure.
	153	*/
	154	static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
	155	char *buf, unsigned int type,
	156	bool only_disabled)
	157	{
	158	int n_events = get_n_events_by_type(type);
	159	unsigned long *bits;
	160	ssize_t ret;
	161	int i;
	162
	163	bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
	164	if (!bits)
	165	return -ENOMEM;
	166
	167	for (i = 0; i < ddata->n_buttons; i++) {
	168	struct gpio_button_data *bdata = &ddata->data[i];
	169
	170	if (bdata->button->type != type)
	171	continue;
	172
	173	if (only_disabled && !bdata->disabled)
	174	continue;
	175
	176	__set_bit(bdata->button->code, bits);
	177	}
	178
	179	ret = bitmap_scnlistprintf(buf, PAGE_SIZE - 2, bits, n_events);
180	buf[ret++] = '\n';
181	buf[ret] = '\0';
182
183	kfree(bits);
184
185	return ret;
186	}
187
188	/**
189	* gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
190	* @ddata: pointer to drvdata
191	* @buf: buffer from userspace that contains stringified bitmap
192	* @type: button type (%EV_KEY, %EV_SW)
193	*
194	* This function parses stringified bitmap from @buf and disables/enables
195	* GPIO buttons accordinly. Returns 0 on success and negative error
196	* on failure.
197	*/
198	static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
199	const char *buf, unsigned int type)
200	{
201	int n_events = get_n_events_by_type(type);
202	unsigned long *bits;
203	ssize_t error;
204	int i;
205
206	bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
207	if (!bits)
208	return -ENOMEM;
209
210	error = bitmap_parselist(buf, bits, n_events);
211	if (error)
212	goto out;
213
214	/* First validate */
215	for (i = 0; i < ddata->n_buttons; i++) {
216	struct gpio_button_data *bdata = &ddata->data[i];
217
218	if (bdata->button->type != type)
219	continue;
220
221	if (test_bit(bdata->button->code, bits) &&
222	!bdata->button->can_disable) {
223	error = -EINVAL;
224	goto out;
225	}
226	}
227
228	mutex_lock(&ddata->disable_lock);
229
230	for (i = 0; i < ddata->n_buttons; i++) {
231	struct gpio_button_data *bdata = &ddata->data[i];
232
233	if (bdata->button->type != type)
234	continue;
235
236	if (test_bit(bdata->button->code, bits))
237	gpio_keys_disable_button(bdata);
238	else
239	gpio_keys_enable_button(bdata);
240	}
241
242	mutex_unlock(&ddata->disable_lock);
243
244	out:
245	kfree(bits);
246	return error;
247	}
248
249	#define ATTR_SHOW_FN(name, type, only_disabled) \
250	static ssize_t gpio_keys_show_##name(struct device *dev, \
251	struct device_attribute *attr, \
252	char *buf) \
253	{ \
254	struct platform_device *pdev = to_platform_device(dev); \
255	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
256	\
257	return gpio_keys_attr_show_helper(ddata, buf, \
258	type, only_disabled); \
259	}
260
261	ATTR_SHOW_FN(keys, EV_KEY, false);
262	ATTR_SHOW_FN(switches, EV_SW, false);
263	ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
264	ATTR_SHOW_FN(disabled_switches, EV_SW, true);
265
266	/*
267	* ATTRIBUTES:
268	*
269	* /sys/devices/platform/gpio-keys/keys [ro]
270	* /sys/devices/platform/gpio-keys/switches [ro]
271	*/
272	static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
273	static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
274
275	#define ATTR_STORE_FN(name, type) \
276	static ssize_t gpio_keys_store_##name(struct device *dev, \
277	struct device_attribute *attr, \
278	const char *buf, \
279	size_t count) \
280	{ \
281	struct platform_device *pdev = to_platform_device(dev); \
282	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
283	ssize_t error; \
284	\
285	error = gpio_keys_attr_store_helper(ddata, buf, type); \
286	if (error) \
287	return error; \
288	\
289	return count; \
290	}
291
292	ATTR_STORE_FN(disabled_keys, EV_KEY);
293	ATTR_STORE_FN(disabled_switches, EV_SW);
294
295	/*
296	* ATTRIBUTES:
297	*
298	* /sys/devices/platform/gpio-keys/disabled_keys [rw]
299	* /sys/devices/platform/gpio-keys/disables_switches [rw]
300	*/
301	static DEVICE_ATTR(disabled_keys, S_IWUSR \| S_IRUGO,
302	gpio_keys_show_disabled_keys,
303	gpio_keys_store_disabled_keys);
304	static DEVICE_ATTR(disabled_switches, S_IWUSR \| S_IRUGO,
305	gpio_keys_show_disabled_switches,
306	gpio_keys_store_disabled_switches);
307
308	static struct attribute *gpio_keys_attrs[] = {
309	&dev_attr_keys.attr,
310	&dev_attr_switches.attr,
311	&dev_attr_disabled_keys.attr,
312	&dev_attr_disabled_switches.attr,
313	NULL,
314	};
315
316	static struct attribute_group gpio_keys_attr_group = {
317	.attrs = gpio_keys_attrs,
318	};
319
6ee88d71	320	static void gpio_keys_report_event(struct gpio_button_data *bdata)
a33466e3	321	{
ce25d7e9 UKK	322	struct gpio_keys_button *button = bdata->button;
ce25d7e9 UKK	323	struct input_dev *input = bdata->input;
a33466e3	324	unsigned int type = button->type ?: EV_KEY;
94a8cab8	325	int state = (gpio_get_value_cansleep(button->gpio) ? 1 : 0) ^ button->active_low;
a33466e3 DB	326
	327	input_event(input, type, button->code, !!state);
	328	input_sync(input);
	329	}
	330
6ee88d71 DM	331	static void gpio_keys_work_func(struct work_struct *work)
	332	{
	333	struct gpio_button_data *bdata =
	334	container_of(work, struct gpio_button_data, work);
	335
	336	gpio_keys_report_event(bdata);
	337	}
	338
da0d03fe	339	static void gpio_keys_timer(unsigned long _data)
ca865a77 JN	340	{
	341	struct gpio_button_data data = (struct gpio_button_data )_data;
	342
da0d03fe	343	schedule_work(&data->work);
ca865a77 JN	344	}
ca865a77 JN	345
78a56aab PB	346	static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
78a56aab PB	347	{
57ffe9d5 UKK	348	struct gpio_button_data *bdata = dev_id;
57ffe9d5 UKK	349	struct gpio_keys_button *button = bdata->button;
78a56aab	350
57ffe9d5	351	BUG_ON(irq != gpio_to_irq(button->gpio));
84767d00	352
28ed684f	353	if (bdata->timer_debounce)
ca865a77	354	mod_timer(&bdata->timer,
28ed684f	355	jiffies + msecs_to_jiffies(bdata->timer_debounce));
ca865a77	356	else
da0d03fe	357	schedule_work(&bdata->work);
78a56aab	358
57ffe9d5	359	return IRQ_HANDLED;
78a56aab PB	360	}
78a56aab PB	361
9e3af04f	362	static int __devinit gpio_keys_setup_key(struct platform_device *pdev,
bc8f1eaf BD	363	struct gpio_button_data *bdata,
	364	struct gpio_keys_button *button)
	365	{
	366	char *desc = button->desc ? button->desc : "gpio_keys";
9e3af04f MW	367	struct device *dev = &pdev->dev;
9e3af04f MW	368	unsigned long irqflags;
bc8f1eaf BD	369	int irq, error;
	370
	371	setup_timer(&bdata->timer, gpio_keys_timer, (unsigned long)bdata);
6ee88d71	372	INIT_WORK(&bdata->work, gpio_keys_work_func);
bc8f1eaf BD	373
	374	error = gpio_request(button->gpio, desc);
	375	if (error < 0) {
	376	dev_err(dev, "failed to request GPIO %d, error %d\n",
	377	button->gpio, error);
	378	goto fail2;
	379	}
	380
	381	error = gpio_direction_input(button->gpio);
	382	if (error < 0) {
	383	dev_err(dev, "failed to configure"
	384	" direction for GPIO %d, error %d\n",
	385	button->gpio, error);
	386	goto fail3;
	387	}
	388
28ed684f GI	389	if (button->debounce_interval) {
	390	error = gpio_set_debounce(button->gpio,
	391	button->debounce_interval * 1000);
	392	/* use timer if gpiolib doesn't provide debounce */
	393	if (error < 0)
	394	bdata->timer_debounce = button->debounce_interval;
	395	}
	396
bc8f1eaf BD	397	irq = gpio_to_irq(button->gpio);
	398	if (irq < 0) {
	399	error = irq;
	400	dev_err(dev, "Unable to get irq number for GPIO %d, error %d\n",
	401	button->gpio, error);
	402	goto fail3;
	403	}
	404
9e3af04f MW	405	irqflags = IRQF_TRIGGER_RISING \| IRQF_TRIGGER_FALLING;
	406	/*
	407	* If platform has specified that the button can be disabled,
	408	* we don't want it to share the interrupt line.
	409	*/
	410	if (!button->can_disable)
	411	irqflags \|= IRQF_SHARED;
	412
94a8cab8 PL	413	error = request_any_context_irq(irq, gpio_keys_isr, irqflags, desc, bdata);
94a8cab8 PL	414	if (error < 0) {
bc8f1eaf BD	415	dev_err(dev, "Unable to claim irq %d; error %d\n",
	416	irq, error);
	417	goto fail3;
	418	}
	419
	420	return 0;
	421
	422	fail3:
	423	gpio_free(button->gpio);
	424	fail2:
	425	return error;
	426	}
	427
173bdd74 S	428	static int gpio_keys_open(struct input_dev *input)
	429	{
	430	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
	431
	432	return ddata->enable ? ddata->enable(input->dev.parent) : 0;
	433	}
	434
	435	static void gpio_keys_close(struct input_dev *input)
	436	{
	437	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
	438
	439	if (ddata->disable)
	440	ddata->disable(input->dev.parent);
	441	}
	442
78a56aab PB	443	static int __devinit gpio_keys_probe(struct platform_device *pdev)
	444	{
	445	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
a33466e3	446	struct gpio_keys_drvdata *ddata;
db19fd8b	447	struct device *dev = &pdev->dev;
78a56aab PB	448	struct input_dev *input;
78a56aab PB	449	int i, error;
e15b0213	450	int wakeup = 0;
78a56aab	451
a33466e3 DB	452	ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
	453	pdata->nbuttons * sizeof(struct gpio_button_data),
	454	GFP_KERNEL);
78a56aab	455	input = input_allocate_device();
a33466e3	456	if (!ddata \|\| !input) {
db19fd8b	457	dev_err(dev, "failed to allocate state\n");
a33466e3 DB	458	error = -ENOMEM;
	459	goto fail1;
	460	}
78a56aab	461
9e3af04f MW	462	ddata->input = input;
9e3af04f MW	463	ddata->n_buttons = pdata->nbuttons;
173bdd74 S	464	ddata->enable = pdata->enable;
173bdd74 S	465	ddata->disable = pdata->disable;
9e3af04f MW	466	mutex_init(&ddata->disable_lock);
9e3af04f MW	467
a33466e3	468	platform_set_drvdata(pdev, ddata);
173bdd74	469	input_set_drvdata(input, ddata);
78a56aab PB	470
	471	input->name = pdev->name;
	472	input->phys = "gpio-keys/input0";
469ba4df	473	input->dev.parent = &pdev->dev;
173bdd74 S	474	input->open = gpio_keys_open;
173bdd74 S	475	input->close = gpio_keys_close;
78a56aab PB	476
	477	input->id.bustype = BUS_HOST;
	478	input->id.vendor = 0x0001;
	479	input->id.product = 0x0001;
	480	input->id.version = 0x0100;
	481
b67b4b11 DC	482	/* Enable auto repeat feature of Linux input subsystem */
	483	if (pdata->rep)
	484	__set_bit(EV_REP, input->evbit);
	485
78a56aab	486	for (i = 0; i < pdata->nbuttons; i++) {
84767d00	487	struct gpio_keys_button *button = &pdata->buttons[i];
a33466e3	488	struct gpio_button_data *bdata = &ddata->data[i];
84767d00	489	unsigned int type = button->type ?: EV_KEY;
78a56aab	490
a33466e3	491	bdata->input = input;
74dd4393	492	bdata->button = button;
bc8f1eaf	493
9e3af04f	494	error = gpio_keys_setup_key(pdev, bdata, button);
bc8f1eaf	495	if (error)
a33466e3	496	goto fail2;
84767d00	497
e15b0213 AS	498	if (button->wakeup)
	499	wakeup = 1;
	500
84767d00	501	input_set_capability(input, type, button->code);
78a56aab PB	502	}
78a56aab PB	503
9e3af04f	504	error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
78a56aab	505	if (error) {
9e3af04f MW	506	dev_err(dev, "Unable to export keys/switches, error: %d\n",
9e3af04f MW	507	error);
a33466e3	508	goto fail2;
78a56aab PB	509	}
78a56aab PB	510
9e3af04f MW	511	error = input_register_device(input);
	512	if (error) {
	513	dev_err(dev, "Unable to register input device, error: %d\n",
	514	error);
	515	goto fail3;
	516	}
	517
6ee88d71 DM	518	/* get current state of buttons */
	519	for (i = 0; i < pdata->nbuttons; i++)
	520	gpio_keys_report_event(&ddata->data[i]);
	521	input_sync(input);
	522
e15b0213 AS	523	device_init_wakeup(&pdev->dev, wakeup);
e15b0213 AS	524
78a56aab PB	525	return 0;
78a56aab PB	526
9e3af04f MW	527	fail3:
9e3af04f MW	528	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
a33466e3	529	fail2:
6a2e3911	530	while (--i >= 0) {
57ffe9d5	531	free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
28ed684f	532	if (ddata->data[i].timer_debounce)
ca865a77	533	del_timer_sync(&ddata->data[i].timer);
da0d03fe	534	cancel_work_sync(&ddata->data[i].work);
6a2e3911 HVR	535	gpio_free(pdata->buttons[i].gpio);
6a2e3911 HVR	536	}
78a56aab	537
006df302	538	platform_set_drvdata(pdev, NULL);
a33466e3	539	fail1:
78a56aab	540	input_free_device(input);
a33466e3	541	kfree(ddata);
78a56aab PB	542
	543	return error;
	544	}
	545
	546	static int __devexit gpio_keys_remove(struct platform_device *pdev)
	547	{
	548	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
a33466e3 DB	549	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
a33466e3 DB	550	struct input_dev *input = ddata->input;
78a56aab PB	551	int i;
78a56aab PB	552
9e3af04f MW	553	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
9e3af04f MW	554
e15b0213 AS	555	device_init_wakeup(&pdev->dev, 0);
e15b0213 AS	556
78a56aab	557	for (i = 0; i < pdata->nbuttons; i++) {
0d98f6bb	558	int irq = gpio_to_irq(pdata->buttons[i].gpio);
57ffe9d5	559	free_irq(irq, &ddata->data[i]);
28ed684f	560	if (ddata->data[i].timer_debounce)
ca865a77	561	del_timer_sync(&ddata->data[i].timer);
da0d03fe	562	cancel_work_sync(&ddata->data[i].work);
6a2e3911	563	gpio_free(pdata->buttons[i].gpio);
78a56aab PB	564	}
	565
	566	input_unregister_device(input);
	567
	568	return 0;
	569	}
	570
e15b0213 AS	571
e15b0213 AS	572	#ifdef CONFIG_PM
ae78e0e0	573	static int gpio_keys_suspend(struct device *dev)
e15b0213	574	{
ae78e0e0	575	struct platform_device *pdev = to_platform_device(dev);
e15b0213 AS	576	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
	577	int i;
	578
	579	if (device_may_wakeup(&pdev->dev)) {
	580	for (i = 0; i < pdata->nbuttons; i++) {
	581	struct gpio_keys_button *button = &pdata->buttons[i];
	582	if (button->wakeup) {
	583	int irq = gpio_to_irq(button->gpio);
	584	enable_irq_wake(irq);
	585	}
	586	}
	587	}
	588
	589	return 0;
	590	}
	591
ae78e0e0	592	static int gpio_keys_resume(struct device *dev)
e15b0213	593	{
ae78e0e0	594	struct platform_device *pdev = to_platform_device(dev);
6ee88d71	595	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
e15b0213 AS	596	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
	597	int i;
	598
6ee88d71 DM	599	for (i = 0; i < pdata->nbuttons; i++) {
	600
	601	struct gpio_keys_button *button = &pdata->buttons[i];
	602	if (button->wakeup && device_may_wakeup(&pdev->dev)) {
	603	int irq = gpio_to_irq(button->gpio);
	604	disable_irq_wake(irq);
e15b0213	605	}
6ee88d71 DM	606
6ee88d71 DM	607	gpio_keys_report_event(&ddata->data[i]);
e15b0213	608	}
6ee88d71	609	input_sync(ddata->input);
e15b0213 AS	610
	611	return 0;
	612	}
ae78e0e0 MR	613
	614	static const struct dev_pm_ops gpio_keys_pm_ops = {
	615	.suspend = gpio_keys_suspend,
	616	.resume = gpio_keys_resume,
	617	};
e15b0213 AS	618	#endif
e15b0213 AS	619
9b07044c	620	static struct platform_driver gpio_keys_device_driver = {
78a56aab PB	621	.probe = gpio_keys_probe,
	622	.remove = __devexit_p(gpio_keys_remove),
	623	.driver = {
	624	.name = "gpio-keys",
d7b5247b	625	.owner = THIS_MODULE,
ae78e0e0 MR	626	#ifdef CONFIG_PM
	627	.pm = &gpio_keys_pm_ops,
	628	#endif
78a56aab PB	629	}
	630	};
	631
	632	static int __init gpio_keys_init(void)
	633	{
	634	return platform_driver_register(&gpio_keys_device_driver);
	635	}
	636
	637	static void __exit gpio_keys_exit(void)
	638	{
	639	platform_driver_unregister(&gpio_keys_device_driver);
	640	}
	641
	642	module_init(gpio_keys_init);
	643	module_exit(gpio_keys_exit);
	644
	645	MODULE_LICENSE("GPL");
	646	MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
	647	MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");
d7b5247b	648	MODULE_ALIAS("platform:gpio-keys");