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
---
Notes:
v2-v3: 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
+#include
#include
#include
#include
@@ -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(>work);
else
- del_timer_sync(>release_timer);
+ hrtimer_cancel(>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(>lock, flags);
if (bdata->key_pressed) {
input_event(input, EV_KEY, *bdata->code, 0);
input_sync(input);
bdata->key_pressed = false;
}
- spin_unlock_irqrestore(>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(>release_timer,
- jiffies + msecs_to_jiffies(bdata->release_delay));
+ hrtimer_start(>release_timer,
+ ms_to_ktime(bdata->release_delay),
+ HRTIMER_MODE_REL_HARD);
out:
spin_unlock_irqrestore(>lock, flags);
return IRQ_HANDLED;
@@ -471,7 +474,7 @@ static void gpio_keys_quiesce_key(void *data)
if (bdata->gpiod)
cancel_delayed_work_sync(>work);
else
- del_timer_sync(>release_timer);
+ hrtimer_cancel(>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(>release_timer, gpio_keys_irq_timer, 0);
+ hrtimer_init(>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
