From: Paul Cercueil <paul@crapouillou.net>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: od@zcrc.me, linux-input@vger.kernel.org,
linux-kernel@vger.kernel.org,
Paul Cercueil <paul@crapouillou.net>
Subject: [PATCH v2 2/3] input: gpio-keys: Use hrtimer for release timer
Date: Sun, 7 Mar 2021 17:34:35 +0000 [thread overview]
Message-ID: <20210307173436.78730-2-paul@crapouillou.net> (raw)
In-Reply-To: <20210307173436.78730-1-paul@crapouillou.net>
Dealing with input, timing is important; if the button should be
released in one millisecond, then it should be done in one millisecond
and not a hundred milliseconds.
Therefore, the standard timer API is not really suitable for this task.
Convert the gpio-keys driver to use a hrtimer instead of the standard
timer to address this issue.
Note that by using a hard IRQ for the hrtimer callback, we can get rid
of the spin_lock_irqsave() and spin_unlock_irqrestore().
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
Notes:
v2: No change
drivers/input/keyboard/gpio_keys.c | 27 ++++++++++++++++-----------
1 file changed, 16 insertions(+), 11 deletions(-)
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 7fcb2c35c5cc..4b92f49decef 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -8,6 +8,7 @@
#include <linux/module.h>
+#include <linux/hrtimer.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
@@ -36,7 +37,7 @@ struct gpio_button_data {
unsigned short *code;
- struct timer_list release_timer;
+ struct hrtimer release_timer;
unsigned int release_delay; /* in msecs, for IRQ-only buttons */
struct delayed_work work;
@@ -146,7 +147,7 @@ static void gpio_keys_disable_button(struct gpio_button_data *bdata)
if (bdata->gpiod)
cancel_delayed_work_sync(&bdata->work);
else
- del_timer_sync(&bdata->release_timer);
+ hrtimer_cancel(&bdata->release_timer);
bdata->disabled = true;
}
@@ -415,19 +416,20 @@ static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
return IRQ_HANDLED;
}
-static void gpio_keys_irq_timer(struct timer_list *t)
+static enum hrtimer_restart gpio_keys_irq_timer(struct hrtimer *t)
{
- struct gpio_button_data *bdata = from_timer(bdata, t, release_timer);
+ struct gpio_button_data *bdata = container_of(t,
+ struct gpio_button_data,
+ release_timer);
struct input_dev *input = bdata->input;
- unsigned long flags;
- spin_lock_irqsave(&bdata->lock, flags);
if (bdata->key_pressed) {
input_event(input, EV_KEY, *bdata->code, 0);
input_sync(input);
bdata->key_pressed = false;
}
- spin_unlock_irqrestore(&bdata->lock, flags);
+
+ return HRTIMER_NORESTART;
}
static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
@@ -457,8 +459,9 @@ static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
}
if (bdata->release_delay)
- mod_timer(&bdata->release_timer,
- jiffies + msecs_to_jiffies(bdata->release_delay));
+ hrtimer_start(&bdata->release_timer,
+ ms_to_ktime(bdata->release_delay),
+ HRTIMER_MODE_REL_HARD);
out:
spin_unlock_irqrestore(&bdata->lock, flags);
return IRQ_HANDLED;
@@ -471,7 +474,7 @@ static void gpio_keys_quiesce_key(void *data)
if (bdata->gpiod)
cancel_delayed_work_sync(&bdata->work);
else
- del_timer_sync(&bdata->release_timer);
+ hrtimer_cancel(&bdata->release_timer);
}
static int gpio_keys_setup_key(struct platform_device *pdev,
@@ -595,7 +598,9 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
}
bdata->release_delay = button->debounce_interval;
- timer_setup(&bdata->release_timer, gpio_keys_irq_timer, 0);
+ hrtimer_init(&bdata->release_timer,
+ CLOCK_REALTIME, HRTIMER_MODE_REL_HARD);
+ bdata->release_timer.function = gpio_keys_irq_timer;
isr = gpio_keys_irq_isr;
irqflags = 0;
--
2.30.1
next prev parent reply other threads:[~2021-03-07 17:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-07 17:34 [PATCH v2 1/3] input: gpio-keys: Remove extra call to input_sync Paul Cercueil
2021-03-07 17:34 ` Paul Cercueil [this message]
2021-03-07 17:34 ` [PATCH v2 3/3] input: gpio-keys: Use hrtimer for software debounce Paul Cercueil
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