From 25bb14c1e78e641049fd1ee0c404a9ccd2755e44 Mon Sep 17 00:00:00 2001

From: Hans de Goede <hdegoede@redhat.com>

Date: Sat, 22 Jul 2017 13:00:05 +0200

Subject: [PATCH 1/2] Input: gpio_keys - Allow suppression of input events for

 wakeup button presses

In some cases it is undesirable for a wakeup button to send input events

to userspace if pressed to wakeup the system (if pressed during suspend).

A typical example of this is the power-button on laptops / tablets,

sending a KEY_POWER event to userspace when woken up with the power-button

will cause userspace to immediately suspend the system again which is

undesirable.

For power-buttons attached to a PMIC, or handled by e.g. ACPI, not sending

an input event in this case is take care of by the PMIC / ACPI hardware /

code. But in the case of a GPIO button we need to explicitly suppress the

sending of the input event.

This commit adds support for this by adding a no_wakeup_events bool to

struct gpio_keys_button, which platform code can set to suppress the

input events for presses of wakeup keys during suspend.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

---

Changes in v2:

-This is a rewrite if my "Input: gpio_keys - Do not report wake button

 presses as evdev events" patch.

-Instead of unconditionally ignoring presses of all wake-up buttons during

 suspend, this rewrite makes this configurable per button

-This version uses a timer to delay clearing the suspended flag for software

 debouncing, rather then jiffy compare magic

---

 drivers/input/keyboard/gpio_keys.c | 33 +++++++++++++++++++++++++++++++--

 include/linux/gpio_keys.h          |  3 +++

 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c

index a047b9af8369..fa3a58620407 100644

--- a/drivers/input/keyboard/gpio_keys.c

+++ b/drivers/input/keyboard/gpio_keys.c

@@ -38,6 +38,7 @@ struct gpio_button_data {

 	unsigned short *code;

+	struct timer_list unsuspend_timer;

 	struct timer_list release_timer;

 	unsigned int release_delay;	/* in msecs, for IRQ-only buttons */

@@ -371,6 +372,9 @@ static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)

 		return;

 	}

+	if (state && bdata->button->no_wakeup_events && bdata->suspended)

+		return;

+

 	if (type == EV_ABS) {

 		if (state)

 			input_event(input, type, button->code, button->value);

@@ -400,6 +404,9 @@ static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)

 	if (bdata->button->wakeup) {

 		const struct gpio_keys_button *button = bdata->button;

+		if (bdata->button->no_wakeup_events && bdata->suspended)

+			return IRQ_HANDLED;

+

 		pm_stay_awake(bdata->input->dev.parent);

 		if (bdata->suspended  &&

 		    (button->type == 0 || button->type == EV_KEY)) {

@@ -445,9 +452,13 @@ static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)

 	spin_lock_irqsave(&bdata->lock, flags);

 	if (!bdata->key_pressed) {

-		if (bdata->button->wakeup)

+		if (bdata->button->wakeup) {

 			pm_wakeup_event(bdata->input->dev.parent, 0);

+			if (bdata->button->no_wakeup_events && bdata->suspended)

+				goto out;

+		}

+

 		input_event(input, EV_KEY, *bdata->code, 1);

 		input_sync(input);

@@ -468,6 +479,13 @@ static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)

 	return IRQ_HANDLED;

 }

+static void gpio_keys_unsuspend_timer(unsigned long _data)

+{

+	struct gpio_button_data *bdata = (struct gpio_button_data *)_data;

+

+	bdata->suspended = false;

+}

+

 static void gpio_keys_quiesce_key(void *data)

 {

 	struct gpio_button_data *bdata = data;

@@ -476,6 +494,8 @@ static void gpio_keys_quiesce_key(void *data)

 		cancel_delayed_work_sync(&bdata->work);

 	else

 		del_timer_sync(&bdata->release_timer);

+

+	del_timer_sync(&bdata->unsuspend_timer);

 }

 static int gpio_keys_setup_key(struct platform_device *pdev,

@@ -496,6 +516,8 @@ static int gpio_keys_setup_key(struct platform_device *pdev,

 	bdata->input = input;

 	bdata->button = button;

 	spin_lock_init(&bdata->lock);

+	setup_timer(&bdata->unsuspend_timer, gpio_keys_unsuspend_timer,

+		    (unsigned long)bdata);

 	if (child) {

 		bdata->gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL,

@@ -868,6 +890,7 @@ static int __maybe_unused gpio_keys_suspend(struct device *dev)

 			struct gpio_button_data *bdata = &ddata->data[i];

 			if (bdata->button->wakeup)

 				enable_irq_wake(bdata->irq);

+			del_timer_sync(&bdata->unsuspend_timer);

 			bdata->suspended = true;

 		}

 	} else {

@@ -892,7 +915,13 @@ static int __maybe_unused gpio_keys_resume(struct device *dev)

 			struct gpio_button_data *bdata = &ddata->data[i];

 			if (bdata->button->wakeup)

 				disable_irq_wake(bdata->irq);

-			bdata->suspended = false;

+			if (bdata->button->no_wakeup_events) {

+				mod_timer(&bdata->unsuspend_timer, jiffies +

+					  msecs_to_jiffies(

+						    bdata->software_debounce));

+			} else {

+				bdata->suspended = false;

+			}

 		}

 	} else {

 		mutex_lock(&input->mutex);

diff --git a/include/linux/gpio_keys.h b/include/linux/gpio_keys.h

index 0b71024c082c..d8a85e52b6bb 100644

--- a/include/linux/gpio_keys.h

+++ b/include/linux/gpio_keys.h

@@ -15,6 +15,8 @@ struct device;

  * @debounce_interval:	debounce ticks interval in msecs

  * @can_disable:	%true indicates that userspace is allowed to

  *			disable button via sysfs

+ * @no_wakeup_events:	For wake-up source buttons only, if %true then no input

+ *			events will be generated if pressed while suspended

  * @value:		axis value for %EV_ABS

  * @irq:		Irq number in case of interrupt keys

  */

@@ -27,6 +29,7 @@ struct gpio_keys_button {

 	int wakeup;

 	int debounce_interval;

 	bool can_disable;

+	bool no_wakeup_events;

 	int value;

 	unsigned int irq;

 };

-- 

2.13.4