Re: [PATCH 2/2] Input: gpio_keys - replace timer and workqueue with delayed workqueue

From: Andy Shevchenko
Date: Wed Dec 10 2014 - 13:42:35 EST


On Sun, 2014-12-07 at 23:21 -0800, Dmitry Torokhov wrote:
> We do not need to roll our own implementation of delayed work now that we
> have proper implementation of mod_delayed_work.
>
> For interrupt-only driven buttons we retain the timer, but we rename
> it to release_timer to better reflect its purpose.

At least it doesn't break the driver on Intel Medfield device.

Tested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> ---
> drivers/input/keyboard/gpio_keys.c | 65 +++++++++++++++++-------------------
> 1 file changed, 31 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
> index a5ece3f..eefd976 100644
> --- a/drivers/input/keyboard/gpio_keys.c
> +++ b/drivers/input/keyboard/gpio_keys.c
> @@ -35,9 +35,13 @@
> struct gpio_button_data {
> const struct gpio_keys_button *button;
> struct input_dev *input;
> - struct timer_list timer;
> - struct work_struct work;
> - unsigned int timer_debounce; /* in msecs */
> +
> + struct timer_list release_timer;
> + unsigned int release_delay; /* in msecs, for IRQ-only buttons */
> +
> + struct delayed_work work;
> + unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
> +
> unsigned int irq;
> spinlock_t lock;
> bool disabled;
> @@ -116,11 +120,14 @@ static void gpio_keys_disable_button(struct gpio_button_data *bdata)
> {
> if (!bdata->disabled) {
> /*
> - * Disable IRQ and possible debouncing timer.
> + * Disable IRQ and associated timer/work structure.
> */
> disable_irq(bdata->irq);
> - if (bdata->timer_debounce)
> - del_timer_sync(&bdata->timer);
> +
> + if (gpio_is_valid(bdata->button->gpio))
> + cancel_delayed_work_sync(&bdata->work);
> + else
> + del_timer_sync(&bdata->release_timer);
>
> bdata->disabled = true;
> }
> @@ -343,7 +350,7 @@ static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
> static void gpio_keys_gpio_work_func(struct work_struct *work)
> {
> struct gpio_button_data *bdata =
> - container_of(work, struct gpio_button_data, work);
> + container_of(work, struct gpio_button_data, work.work);
>
> gpio_keys_gpio_report_event(bdata);
>
> @@ -351,13 +358,6 @@ static void gpio_keys_gpio_work_func(struct work_struct *work)
> pm_relax(bdata->input->dev.parent);
> }
>
> -static void gpio_keys_gpio_timer(unsigned long _data)
> -{
> - struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
> -
> - schedule_work(&bdata->work);
> -}
> -
> static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
> {
> struct gpio_button_data *bdata = dev_id;
> @@ -366,11 +366,10 @@ static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
>
> if (bdata->button->wakeup)
> pm_stay_awake(bdata->input->dev.parent);
> - if (bdata->timer_debounce)
> - mod_timer(&bdata->timer,
> - jiffies + msecs_to_jiffies(bdata->timer_debounce));
> - else
> - schedule_work(&bdata->work);
> +
> + mod_delayed_work(system_wq,
> + &bdata->work,
> + msecs_to_jiffies(bdata->software_debounce));
>
> return IRQ_HANDLED;
> }
> @@ -408,7 +407,7 @@ static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
> input_event(input, EV_KEY, button->code, 1);
> input_sync(input);
>
> - if (!bdata->timer_debounce) {
> + if (!bdata->release_delay) {
> input_event(input, EV_KEY, button->code, 0);
> input_sync(input);
> goto out;
> @@ -417,9 +416,9 @@ static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
> bdata->key_pressed = true;
> }
>
> - if (bdata->timer_debounce)
> - mod_timer(&bdata->timer,
> - jiffies + msecs_to_jiffies(bdata->timer_debounce));
> + if (bdata->release_delay)
> + mod_timer(&bdata->release_timer,
> + jiffies + msecs_to_jiffies(bdata->release_delay));
> out:
> spin_unlock_irqrestore(&bdata->lock, flags);
> return IRQ_HANDLED;
> @@ -429,10 +428,10 @@ static void gpio_keys_quiesce_key(void *data)
> {
> struct gpio_button_data *bdata = data;
>
> - if (bdata->timer_debounce)
> - del_timer_sync(&bdata->timer);
> -
> - cancel_work_sync(&bdata->work);
> + if (gpio_is_valid(bdata->button->gpio))
> + cancel_delayed_work_sync(&bdata->work);
> + else
> + del_timer_sync(&bdata->release_timer);
> }
>
> static int gpio_keys_setup_key(struct platform_device *pdev,
> @@ -466,7 +465,7 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
> button->debounce_interval * 1000);
> /* use timer if gpiolib doesn't provide debounce */
> if (error < 0)
> - bdata->timer_debounce =
> + bdata->software_debounce =
> button->debounce_interval;
> }
>
> @@ -484,9 +483,7 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
> bdata->irq = irq;
> }
>
> - INIT_WORK(&bdata->work, gpio_keys_gpio_work_func);
> - setup_timer(&bdata->timer,
> - gpio_keys_gpio_timer, (unsigned long)bdata);
> + INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
>
> isr = gpio_keys_gpio_isr;
> irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
> @@ -503,8 +500,8 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
> return -EINVAL;
> }
>
> - bdata->timer_debounce = button->debounce_interval;
> - setup_timer(&bdata->timer,
> + bdata->release_delay = button->debounce_interval;
> + setup_timer(&bdata->release_timer,
> gpio_keys_irq_timer, (unsigned long)bdata);
>
> isr = gpio_keys_irq_isr;
> @@ -514,7 +511,7 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
> input_set_capability(input, button->type ?: EV_KEY, button->code);
>
> /*
> - * Install custom action to cancel debounce timer and
> + * Install custom action to cancel release timer and
> * workqueue item.
> */
> error = devm_add_action(&pdev->dev, gpio_keys_quiesce_key, bdata);
>


--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
Intel Finland Oy

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