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Groups > linux.kernel > #1731754
| From | David Lin <dtwlin@google.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v2 2/3] leds: Add the LED_BRIGHTNESS_FAST flag |
| Date | 2017-09-13 20:00 +0200 |
| Message-ID | <upk77-227-3@gated-at.bofh.it> (permalink) |
| References | <upk77-227-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
This patch adds the LED_BRIGHTNESS_FAST flag to allow the driver to
indicate that the brightness_set() callback is implemented on a fastpath
so that the LED core may choose to for example use a hrtimer to
implement the duration of a trigger for better timing accuracy.
Suggested-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: David Lin <dtwlin@google.com>
---
Documentation/leds/leds-class.txt | 5 +++++
include/linux/leds.h | 1 +
2 files changed, 6 insertions(+)
diff --git a/Documentation/leds/leds-class.txt b/Documentation/leds/leds-class.txt
index 836cb16d6f09..70d7a3dca621 100644
--- a/Documentation/leds/leds-class.txt
+++ b/Documentation/leds/leds-class.txt
@@ -80,6 +80,11 @@ flag must be set in flags before registering. Calling
led_classdev_notify_brightness_hw_changed on a classdev not registered with
the LED_BRIGHT_HW_CHANGED flag is a bug and will trigger a WARN_ON.
+Optionally, the driver may choose to register with the LED_BRIGHTNESS_FAST flag.
+This flag indicates that the driver implements the brightness_set() callback
+function using a fastpath so the LED core can use hrtimer if the driver requires
+high precision for the trigger timing.
+
Hardware accelerated blink of LEDs
==================================
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 5579c64c8fd6..ccfa0a1799fe 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -50,6 +50,7 @@ struct led_classdev {
#define LED_PANIC_INDICATOR BIT(20)
#define LED_BRIGHT_HW_CHANGED BIT(21)
#define LED_RETAIN_AT_SHUTDOWN BIT(22)
+#define LED_BRIGHTNESS_FAST BIT(23)
/* set_brightness_work / blink_timer flags, atomic, private. */
unsigned long work_flags;
--
2.14.1.581.gf28d330327-goog
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[PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer David Lin <dtwlin@google.com> - 2017-09-13 20:00 +0200
[PATCH v2 2/3] leds: Add the LED_BRIGHTNESS_FAST flag David Lin <dtwlin@google.com> - 2017-09-13 20:00 +0200
[PATCH v2 3/3] led: ledtrig-transient: add support for hrtimer David Lin <dtwlin@google.com> - 2017-09-13 20:00 +0200
[PATCH v2 1/3] leds: Replace flags bit shift with BIT() macros David Lin <dtwlin@google.com> - 2017-09-13 20:00 +0200
Re: [PATCH v2 1/3] leds: Replace flags bit shift with BIT() macros Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-14 21:50 +0200
Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-13 22:30 +0200
Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer David Lin <dtwlin@google.com> - 2017-09-13 23:30 +0200
Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-13 23:40 +0200
Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer David Lin <dtwlin@google.com> - 2017-09-14 19:40 +0200
Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-14 21:50 +0200
Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-14 21:40 +0200
Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer David Lin <dtwlin@google.com> - 2017-09-14 21:40 +0200
Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-14 22:10 +0200
Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-14 23:00 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Dmitry Torokhov <dmitry.torokhov@gmail.com> - 2017-09-15 20:40 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-16 00:00 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Dmitry Torokhov <dmitry.torokhov@gmail.com> - 2017-09-16 00:40 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-17 18:50 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-17 20:30 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-17 23:20 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-18 23:00 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Dmitry Torokhov <dmitry.torokhov@gmail.com> - 2017-09-19 00:30 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-19 22:50 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Dmitry Torokhov <dmitry.torokhov@gmail.com> - 2017-09-19 23:10 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-20 21:40 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-20 13:30 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-20 22:10 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-20 13:30 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-16 15:10 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-16 00:00 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-16 14:40 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-17 18:50 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-17 20:00 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-18 22:50 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Pavel Machek <pavel@ucw.cz> - 2017-09-20 13:20 +0200
Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2017-09-20 20:50 +0200
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