Input: gpio-keys - add support for disabling gpios through sysfs (9e3af04f) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/input/keyboard/gpio_keys.c

+307 −11

Original line number	Original line	Diff line number	Diff line
	@@ -30,13 +30,289 @@ struct gpio_button_data {
	struct input_dev *input;		struct input_dev *input;
	struct timer_list timer;		struct timer_list timer;
	struct work_struct work;		struct work_struct work;
			bool disabled;
	};		};

	struct gpio_keys_drvdata {		struct gpio_keys_drvdata {
	struct input_dev *input;		struct input_dev *input;
			struct mutex disable_lock;
			unsigned int n_buttons;
	struct gpio_button_data data[0];		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->button->debounce_interval)
			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)		static void gpio_keys_report_event(struct gpio_button_data *bdata)
	{		{
	struct gpio_keys_button *button = bdata->button;		struct gpio_keys_button *button = bdata->button;
	@@ -79,11 +355,13 @@ static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
	return IRQ_HANDLED;		return IRQ_HANDLED;
	}		}

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

	setup_timer(&bdata->timer, gpio_keys_timer, (unsigned long)bdata);		setup_timer(&bdata->timer, gpio_keys_timer, (unsigned long)bdata);
	@@ -112,10 +390,15 @@ static int __devinit gpio_keys_setup_key(struct device *dev,
	goto fail3;		goto fail3;
	}		}

	error = request_irq(irq, gpio_keys_isr,		irqflags = IRQF_TRIGGER_RISING \| IRQF_TRIGGER_FALLING;
	IRQF_SHARED \|		/*
	IRQF_TRIGGER_RISING \| IRQF_TRIGGER_FALLING,		* If platform has specified that the button can be disabled,
	desc, bdata);		* we don't want it to share the interrupt line.
			*/
			if (!button->can_disable)
			irqflags \|= IRQF_SHARED;

			error = request_irq(irq, gpio_keys_isr, irqflags, desc, bdata);
	if (error) {		if (error) {
	dev_err(dev, "Unable to claim irq %d; error %d\n",		dev_err(dev, "Unable to claim irq %d; error %d\n",
	irq, error);		irq, error);
	@@ -149,6 +432,10 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
	goto fail1;		goto fail1;
	}		}

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

	platform_set_drvdata(pdev, ddata);		platform_set_drvdata(pdev, ddata);

	input->name = pdev->name;		input->name = pdev->name;
	@@ -164,8 +451,6 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
	if (pdata->rep)		if (pdata->rep)
	__set_bit(EV_REP, input->evbit);		__set_bit(EV_REP, input->evbit);

	ddata->input = input;

	for (i = 0; i < pdata->nbuttons; i++) {		for (i = 0; i < pdata->nbuttons; i++) {
	struct gpio_keys_button *button = &pdata->buttons[i];		struct gpio_keys_button *button = &pdata->buttons[i];
	struct gpio_button_data *bdata = &ddata->data[i];		struct gpio_button_data *bdata = &ddata->data[i];
	@@ -174,7 +459,7 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
	bdata->input = input;		bdata->input = input;
	bdata->button = button;		bdata->button = button;

	error = gpio_keys_setup_key(dev, bdata, button);		error = gpio_keys_setup_key(pdev, bdata, button);
	if (error)		if (error)
	goto fail2;		goto fail2;

	@@ -184,13 +469,20 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
	input_set_capability(input, type, button->code);		input_set_capability(input, type, button->code);
	}		}

	error = input_register_device(input);		error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
	if (error) {		if (error) {
	dev_err(dev, "Unable to register input device, "		dev_err(dev, "Unable to export keys/switches, error: %d\n",
	"error: %d\n", error);		error);
	goto fail2;		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 */		/* get current state of buttons */
	for (i = 0; i < pdata->nbuttons; i++)		for (i = 0; i < pdata->nbuttons; i++)
	gpio_keys_report_event(&ddata->data[i]);		gpio_keys_report_event(&ddata->data[i]);
	@@ -200,6 +492,8 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)

	return 0;		return 0;

			fail3:
			sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
	fail2:		fail2:
	while (--i >= 0) {		while (--i >= 0) {
	free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);		free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
	@@ -224,6 +518,8 @@ static int __devexit gpio_keys_remove(struct platform_device *pdev)
	struct input_dev *input = ddata->input;		struct input_dev *input = ddata->input;
	int i;		int i;

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

	device_init_wakeup(&pdev->dev, 0);		device_init_wakeup(&pdev->dev, 0);

	for (i = 0; i < pdata->nbuttons; i++) {		for (i = 0; i < pdata->nbuttons; i++) {

include/linux/gpio_keys.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -10,6 +10,7 @@ struct gpio_keys_button {
	int type; /* input event type (EV_KEY, EV_SW) */		int type; /* input event type (EV_KEY, EV_SW) */
	int wakeup; /* configure the button as a wake-up source */		int wakeup; /* configure the button as a wake-up source */
	int debounce_interval; /* debounce ticks interval in msecs */		int debounce_interval; /* debounce ticks interval in msecs */
			bool can_disable;
	};		};

	struct gpio_keys_platform_data {		struct gpio_keys_platform_data {