This patch replaces the kernel timer used by led transient trigger as an
one-shot timer with an hrtimer. As Android is moving away from the
obsoleted timed_output to ledtrig-transient for the vibrator HAL,
ledtrig-transient needs to be able to handle the "duration" property to
millisecond precision as modern haptic actuators can be driven in
precisely one cycle (~1 ms) in order to provide a crisp and subtle
feedback.
Cc: Richard Purdie <rpurdie@xxxxxxxxx>
Cc: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Rom Lemarchand <romlem@xxxxxxxxxx>
Cc: Joel Fernandes <joelaf@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: David Lin <dtwlin@xxxxxxxxxx>
---
drivers/leds/trigger/ledtrig-transient.c | 29 +++++++++++++++++------------
1 file changed, 17 insertions(+), 12 deletions(-)
diff --git a/drivers/leds/trigger/ledtrig-transient.c b/drivers/leds/trigger/ledtrig-transient.c
index 7e6011bd3646..94bb3bfc46e9 100644
--- a/drivers/leds/trigger/ledtrig-transient.c
+++ b/drivers/leds/trigger/ledtrig-transient.c
@@ -23,25 +23,28 @@
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
-#include <linux/timer.h>
+#include <linux/hrtimer.h>
#include <linux/leds.h>
#include "../leds.h"
struct transient_trig_data {
+ struct led_classdev *led_cdev;
int activate;
int state;
int restore_state;
unsigned long duration;
- struct timer_list timer;
+ struct hrtimer timer;
};
-static void transient_timer_function(unsigned long data)
+static enum hrtimer_restart transient_timer_function(struct hrtimer *timer)
{
- struct led_classdev *led_cdev = (struct led_classdev *) data;
- struct transient_trig_data *transient_data = led_cdev->trigger_data;
+ struct transient_trig_data *transient_data =
+ container_of(timer, struct transient_trig_data, timer);
transient_data->activate = 0;
- led_set_brightness_nosleep(led_cdev, transient_data->restore_state);
+ led_set_brightness_nosleep(transient_data->led_cdev,
+ transient_data->restore_state);
+ return HRTIMER_NORESTART;
}
static ssize_t transient_activate_show(struct device *dev,
@@ -70,7 +73,7 @@ static ssize_t transient_activate_store(struct device *dev,
/* cancel the running timer */
if (state == 0 && transient_data->activate == 1) {
- del_timer(&transient_data->timer);
+ hrtimer_cancel(&transient_data->timer);
transient_data->activate = state;
led_set_brightness_nosleep(led_cdev,
transient_data->restore_state);
@@ -84,8 +87,9 @@ static ssize_t transient_activate_store(struct device *dev,
led_set_brightness_nosleep(led_cdev, transient_data->state);
transient_data->restore_state =
(transient_data->state == LED_FULL) ? LED_OFF : LED_FULL;
- mod_timer(&transient_data->timer,
- jiffies + msecs_to_jiffies(transient_data->duration));
+ hrtimer_start(&transient_data->timer,
+ ms_to_ktime(transient_data->duration),
+ HRTIMER_MODE_REL);
}
/* state == 0 && transient_data->activate == 0
@@ -168,6 +172,7 @@ static void transient_trig_activate(struct led_classdev *led_cdev)
"unable to allocate transient trigger\n");
return;
}
+ tdata->led_cdev = led_cdev;
led_cdev->trigger_data = tdata;
rc = device_create_file(led_cdev->dev, &dev_attr_activate);
@@ -182,8 +187,8 @@ static void transient_trig_activate(struct led_classdev *led_cdev)
if (rc)
goto err_out_state;
- setup_timer(&tdata->timer, transient_timer_function,
- (unsigned long) led_cdev);
+ hrtimer_init(&tdata->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ tdata->timer.function = transient_timer_function;
led_cdev->activated = true;
return;
@@ -203,7 +208,7 @@ static void transient_trig_deactivate(struct led_classdev *led_cdev)
struct transient_trig_data *transient_data = led_cdev->trigger_data;
if (led_cdev->activated) {
- del_timer_sync(&transient_data->timer);
+ hrtimer_cancel(&transient_data->timer);
led_set_brightness_nosleep(led_cdev,
transient_data->restore_state);
device_remove_file(led_cdev->dev, &dev_attr_activate);
--
2.12.2.816.g2cccc81164-goog