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Date: Mon, 5 Mar 2018 16:30:09 -0800
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: Jeffy Chen <jeffy.chen@...k-chips.com>
Cc: linux-kernel@...r.kernel.org, briannorris@...gle.com,
heiko@...ech.de, dtor@...gle.com, dianders@...gle.com,
Guenter Roeck <linux@...ck-us.net>,
Enric Balletbo i Serra <enric.balletbo@...labora.com>,
Thomas Gleixner <tglx@...utronix.de>,
Joseph Lo <josephl@...dia.com>,
stephen lu <lumotuwe@...il.com>,
Kate Stewart <kstewart@...uxfoundation.org>,
linux-input@...r.kernel.org,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Philippe Ombredanne <pombredanne@...b.com>,
Arvind Yadav <arvind.yadav.cs@...il.com>
Subject: Re: [PATCH v3 1/3] Input: gpio-keys - add support for wakeup event
action
Hi Jeffy,
On Fri, Mar 02, 2018 at 11:51:00AM +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@...omium.org>
> Signed-off-by: Jeffy Chen <jeffy.chen@...k-chips.com>
> ---
>
> Changes in v3:
> Adding more comments as Brian suggested.
>
> Changes in v2:
> Specify wakeup event action instead of irq trigger type as Brian
> suggested.
>
> drivers/input/keyboard/gpio_keys.c | 39 ++++++++++++++++++++++++++++++++++
> include/linux/gpio_keys.h | 2 ++
> include/uapi/linux/input-event-codes.h | 9 ++++++++
> 3 files changed, 50 insertions(+)
>
> diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
> index 87e613dc33b8..607f3960c886 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 +572,22 @@ 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;
IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
> + break;
> + case EV_ACT_DEASSERTED:
> + bdata->wakeup_trigger_type = active_low ?
> + IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
> + break;
case EV_ACT_ANY:
> + default:
> + /*
> + * For other cases, we are OK letting suspend/resume
> + * not reconfigure the trigger type.
> + */
> + break;
> + }
> } else {
> if (!button->irq) {
> dev_err(dev, "Found button without gpio or irq\n");
> @@ -586,6 +606,12 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
>
> isr = gpio_keys_irq_isr;
> irqflags = 0;
> +
> + /*
> + * For IRQ buttons, the irq trigger type for press and release
> + * are the same. So we don't need to reconfigure the trigger
> + * type for wakeup.
That is not entirely accurate. Interrupt triggers button press, which is
followed by either immediate or delayed release. There is no interrupt
for release.
> + */
> }
>
> bdata->code = &ddata->keymap[idx];
> @@ -618,6 +644,8 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
> return error;
> }
>
> + bdata->irq_trigger_type = irq_get_trigger_type(bdata->irq);
Why do we need to store the trigger type? It is always both edges for
gpio-based keys and we do not support changing wakeup trigger for
interrupt-based keys.
> +
> return 0;
> }
>
> @@ -718,6 +746,9 @@ 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 +885,10 @@ 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) {
if (bdata->wakeup_trigger_type) {
error = ...;
}
enable_irq_wake(bdata->irq);
}
Might need to be split into a helper; if you add error handling to
enable_irq_wake() that woudl be great too.
> if (bdata->button->wakeup)
> enable_irq_wake(bdata->irq);
> bdata->suspended = true;
> @@ -878,6 +913,10 @@ 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);
Just use IRQ_TYPE_EDGE_BOTH.
> 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 */
These do not belong here: they are of no interest to userspace but
simply a driver specific quirk. If you want to share symbolic names add
include/dt-bindings/input/gpio-keys.h
> +#define EV_ACT_MAX 0x02
> +#define EV_ACT_CNT (EV_ACT_MAX+1)
These are not needed at all: you are not defining input bitmasks.
> +
> +/*
> * Event types
> */
>
> --
> 2.11.0
>
>
Thanks.
--
Dmitry
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