leds: blink resolution improvements

index 795ec99..f95ce912 100644
@@ -102,20 +102,21 @@ static const struct attribute_group *led_groups[] = {
 	NULL,
 };
 
-static void led_timer_function(unsigned long data)
+static enum hrtimer_restart led_timer_function(struct hrtimer *timer)
 {
-	struct led_classdev *led_cdev = (void *)data;
+	struct led_classdev *led_cdev = container_of(timer,
+			     struct led_classdev, blink_timer);
 	unsigned long brightness;
 	unsigned long delay;
 
 	if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
 		led_set_brightness_async(led_cdev, LED_OFF);
-		return;
+		return HRTIMER_NORESTART;
 	}
 
 	if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) {
 		led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
-		return;
+		return HRTIMER_NORESTART;
 	}
 
 	brightness = led_get_brightness(led_cdev);

@@ -148,7 +149,10 @@ static void led_timer_function(unsigned long data)
 		}
 	}
 
-	mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
+	hrtimer_forward(&led_cdev->blink_timer,
+			hrtimer_get_expires(&led_cdev->blink_timer),
+			ms_to_ktime(delay));
+	return HRTIMER_RESTART;
 }
 
 static void set_brightness_delayed(struct work_struct *ws)

@@ -243,8 +247,9 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
 
 	INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
 
-	setup_timer(&led_cdev->blink_timer, led_timer_function,
-		    (unsigned long)led_cdev);
+	hrtimer_init(&led_cdev->blink_timer, CLOCK_MONOTONIC,
+		     HRTIMER_MODE_REL);
+	led_cdev->blink_timer.function = led_timer_function;
 
 #ifdef CONFIG_LEDS_TRIGGERS
 	led_trigger_set_default(led_cdev);

index 9886dac..2937259 100644
@@ -52,7 +52,8 @@ static void led_set_software_blink(struct led_classdev *led_cdev,
 		return;
 	}
 
-	mod_timer(&led_cdev->blink_timer, jiffies + 1);
+	hrtimer_start(&led_cdev->blink_timer, ktime_set(0, 0),
+		      HRTIMER_MODE_REL);
 }
 
 

@@ -76,7 +77,7 @@ void led_blink_set(struct led_classdev *led_cdev,
 		   unsigned long *delay_on,
 		   unsigned long *delay_off)
 {
-	del_timer_sync(&led_cdev->blink_timer);
+	hrtimer_cancel(&led_cdev->blink_timer);
 
 	led_cdev->flags &= ~LED_BLINK_ONESHOT;
 	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;

@@ -91,7 +92,7 @@ void led_blink_set_oneshot(struct led_classdev *led_cdev,
 			   int invert)
 {
 	if ((led_cdev->flags & LED_BLINK_ONESHOT) &&
-	     timer_pending(&led_cdev->blink_timer))
+	     hrtimer_active(&led_cdev->blink_timer))
 		return;
 
 	led_cdev->flags |= LED_BLINK_ONESHOT;

@@ -108,7 +109,7 @@ EXPORT_SYMBOL(led_blink_set_oneshot);
 
 void led_stop_software_blink(struct led_classdev *led_cdev)
 {
-	del_timer_sync(&led_cdev->blink_timer);
+	hrtimer_cancel(&led_cdev->blink_timer);
 	led_cdev->blink_delay_on = 0;
 	led_cdev->blink_delay_off = 0;
 }

index f70f84f..68f5a23 100644
@@ -16,7 +16,7 @@
 #include <linux/mutex.h>
 #include <linux/rwsem.h>
 #include <linux/spinlock.h>
-#include <linux/timer.h>
+#include <linux/hrtimer.h>
 #include <linux/workqueue.h>
 
 struct device;

@@ -81,7 +81,7 @@ struct led_classdev {
 	const char		*default_trigger;	/* Trigger to use */
 
 	unsigned long		 blink_delay_on, blink_delay_off;
-	struct timer_list	 blink_timer;
+	struct hrtimer		 blink_timer;
 	int			 blink_brightness;
 	void			(*flash_resume)(struct led_classdev *led_cdev);
 

index f95ce912..2cfbb9d 100644
@@ -108,6 +108,7 @@ static enum hrtimer_restart led_timer_function(struct hrtimer *timer)
 			     struct led_classdev, blink_timer);
 	unsigned long brightness;
 	unsigned long delay;
+	ktime_t k_delay;
 
 	if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
 		led_set_brightness_async(led_cdev, LED_OFF);

@@ -149,9 +150,22 @@ static enum hrtimer_restart led_timer_function(struct hrtimer *timer)
 		}
 	}
 
+	switch (led_cdev->resolution) {
+	case LED_BLINK_MS:
+		k_delay = ms_to_ktime(delay);
+		break;
+	case LED_BLINK_US:
+		k_delay = ns_to_ktime(delay * 1000);
+		break;
+	case LED_BLINK_NS:
+		k_delay = ns_to_ktime(delay);
+		break;
+	default:
+		/* should not happen */
+		return HRTIMER_NORESTART;
+	}
 	hrtimer_forward(&led_cdev->blink_timer,
-			hrtimer_get_expires(&led_cdev->blink_timer),
-			ms_to_ktime(delay));
+			hrtimer_get_expires(&led_cdev->blink_timer), k_delay);
 	return HRTIMER_RESTART;
 }
 

75 lines not on this page · raw message

index 68f5a23..5e6fe26 100644
@@ -30,10 +30,17 @@ enum led_brightness {
 	LED_FULL	= 255,
 };
 
+enum led_blink_resolution {
+	LED_BLINK_MS,
+	LED_BLINK_US,
+	LED_BLINK_NS,
+};
+
 struct led_classdev {
 	const char		*name;
 	enum led_brightness	 brightness;
 	enum led_brightness	 max_brightness;
+	enum led_blink_resolution resolution;
 	int			 flags;
 
 	/* Lower 16 bits reflect status */