Re: [PATCH v2 1/3] Input: gpio-keys - add support for wakeup event action

[Brian Norris]

Hi Jeffy,

On Sat, Feb 10, 2018 at 07:09:05PM +0800, Jeffy Chen wrote:
> Add support for specifying event actions to trigger wakeup when using
> the gpio-keys input device as a wakeup source.
> 
> This would allow the device to configure when to wakeup the system. For
> example a gpio-keys input device for pen insert, may only want to wakeup
> the system when ejecting the pen.
> 
> Suggested-by: Brian Norris <briannorris@xxxxxxxxxxxx>
> Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
> ---
> 
> Changes in v2:
> Specify wakeup event action instead of irq trigger type as Brian
> suggested.
> 
>  drivers/input/keyboard/gpio_keys.c     | 27 +++++++++++++++++++++++++++
>  include/linux/gpio_keys.h              |  2 ++
>  include/uapi/linux/input-event-codes.h |  9 +++++++++
>  3 files changed, 38 insertions(+)
> 
> diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
> index 87e613dc33b8..5c57339d3999 100644
> --- a/drivers/input/keyboard/gpio_keys.c
> +++ b/drivers/input/keyboard/gpio_keys.c
> @@ -45,6 +45,8 @@ struct gpio_button_data {
>  	unsigned int software_debounce;	/* in msecs, for GPIO-driven buttons */
>  
>  	unsigned int irq;
> +	unsigned int irq_trigger_type;
> +	unsigned int wakeup_trigger_type;
>  	spinlock_t lock;
>  	bool disabled;
>  	bool key_pressed;
> @@ -540,6 +542,8 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
>  	}
>  
>  	if (bdata->gpiod) {
> +		int active_low = gpiod_is_active_low(bdata->gpiod);
> +
>  		if (button->debounce_interval) {
>  			error = gpiod_set_debounce(bdata->gpiod,
>  					button->debounce_interval * 1000);
> @@ -568,6 +572,16 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
>  		isr = gpio_keys_gpio_isr;
>  		irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
>  
> +		switch (button->wakeup_event_action) {
> +		case EV_ACT_ASSERTED:
> +			bdata->wakeup_trigger_type = active_low ?
> +				IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
> +			break;
> +		case EV_ACT_DEASSERTED:
> +			bdata->wakeup_trigger_type = active_low ?
> +				IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
> +			break;

What about EV_ACT_ANY? And default case? I think for ANY, we're OK
letting suspend/resume not reconfigure the trigger type, but maybe a
comment here to note that?

> +		}
>  	} else {

What about the 'else' case? Shouldn't we try to handle that?

Brian

>  		if (!button->irq) {
>  			dev_err(dev, "Found button without gpio or irq\n");
> @@ -618,6 +632,8 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
>  		return error;
>  	}
>  
> +	bdata->irq_trigger_type = irq_get_trigger_type(bdata->irq);
> +
>  	return 0;
>  }
>  
> @@ -718,6 +734,9 @@ gpio_keys_get_devtree_pdata(struct device *dev)
>  			/* legacy name */
>  			fwnode_property_read_bool(child, "gpio-key,wakeup");
>  
> +		fwnode_property_read_u32(child, "wakeup-event-action",
> +					 &button->wakeup_event_action);
> +
>  		button->can_disable =
>  			fwnode_property_read_bool(child, "linux,can-disable");
>  
> @@ -854,6 +873,10 @@ static int __maybe_unused gpio_keys_suspend(struct device *dev)
>  	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 && bdata->wakeup_trigger_type)
> +				irq_set_irq_type(bdata->irq,
> +						 bdata->wakeup_trigger_type);
>  			if (bdata->button->wakeup)
>  				enable_irq_wake(bdata->irq);
>  			bdata->suspended = true;
> @@ -878,6 +901,10 @@ static int __maybe_unused gpio_keys_resume(struct device *dev)
>  	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 && bdata->wakeup_trigger_type)
> +				irq_set_irq_type(bdata->irq,
> +						 bdata->irq_trigger_type);
>  			if (bdata->button->wakeup)
>  				disable_irq_wake(bdata->irq);
>  			bdata->suspended = false;
> diff --git a/include/linux/gpio_keys.h b/include/linux/gpio_keys.h
> index d06bf77400f1..7160df54a6fe 100644
> --- a/include/linux/gpio_keys.h
> +++ b/include/linux/gpio_keys.h
> @@ -13,6 +13,7 @@ struct device;
>   * @desc:		label that will be attached to button's gpio
>   * @type:		input event type (%EV_KEY, %EV_SW, %EV_ABS)
>   * @wakeup:		configure the button as a wake-up source
> + * @wakeup_event_action:	event action to trigger wakeup
>   * @debounce_interval:	debounce ticks interval in msecs
>   * @can_disable:	%true indicates that userspace is allowed to
>   *			disable button via sysfs
> @@ -26,6 +27,7 @@ struct gpio_keys_button {
>  	const char *desc;
>  	unsigned int type;
>  	int wakeup;
> +	int wakeup_event_action;
>  	int debounce_interval;
>  	bool can_disable;
>  	int value;
> diff --git a/include/uapi/linux/input-event-codes.h b/include/uapi/linux/input-event-codes.h
> index 53fbae27b280..d7917b0bd438 100644
> --- a/include/uapi/linux/input-event-codes.h
> +++ b/include/uapi/linux/input-event-codes.h
> @@ -32,6 +32,15 @@
>  #define INPUT_PROP_CNT			(INPUT_PROP_MAX + 1)
>  
>  /*
> + * Event action types
> + */
> +#define EV_ACT_ANY			0x00	/* asserted or deasserted */
> +#define EV_ACT_ASSERTED			0x01	/* asserted */
> +#define EV_ACT_DEASSERTED		0x02	/* deasserted */
> +#define EV_ACT_MAX			0x02
> +#define EV_ACT_CNT			(EV_ACT_MAX+1)
> +
> +/*
>   * Event types
>   */
>  
> -- 
> 2.11.0
> 
>