diff options
Diffstat (limited to 'Documentation/ABI/testing')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-led-driver-sc27xx | 22 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-led-trigger-pattern | 82 |
2 files changed, 104 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-led-driver-sc27xx b/Documentation/ABI/testing/sysfs-class-led-driver-sc27xx new file mode 100644 index 000000000000..45b1e605d355 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led-driver-sc27xx @@ -0,0 +1,22 @@ +What: /sys/class/leds/<led>/hw_pattern +Date: September 2018 +KernelVersion: 4.20 +Description: + Specify a hardware pattern for the SC27XX LED. For the SC27XX + LED controller, it only supports 4 stages to make a single + hardware pattern, which is used to configure the rise time, + high time, fall time and low time for the breathing mode. + + For the breathing mode, the SC27XX LED only expects one brightness + for the high stage. To be compatible with the hardware pattern + format, we should set brightness as 0 for rise stage, fall + stage and low stage. + + Min stage duration: 125 ms + Max stage duration: 31875 ms + + Since the stage duration step is 125 ms, the duration should be + a multiplier of 125, like 125ms, 250ms, 375ms, 500ms ... 31875ms. + + Thus the format of the hardware pattern values should be: + "0 rise_duration brightness high_duration 0 fall_duration 0 low_duration". diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-pattern b/Documentation/ABI/testing/sysfs-class-led-trigger-pattern new file mode 100644 index 000000000000..fb3d1e03b881 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led-trigger-pattern @@ -0,0 +1,82 @@ +What: /sys/class/leds/<led>/pattern +Date: September 2018 +KernelVersion: 4.20 +Description: + Specify a software pattern for the LED, that supports altering + the brightness for the specified duration with one software + timer. It can do gradual dimming and step change of brightness. + + The pattern is given by a series of tuples, of brightness and + duration (ms). The LED is expected to traverse the series and + each brightness value for the specified duration. Duration of + 0 means brightness should immediately change to new value, and + writing malformed pattern deactivates any active one. + + 1. For gradual dimming, the dimming interval now is set as 50 + milliseconds. So the tuple with duration less than dimming + interval (50ms) is treated as a step change of brightness, + i.e. the subsequent brightness will be applied without adding + intervening dimming intervals. + + The gradual dimming format of the software pattern values should be: + "brightness_1 duration_1 brightness_2 duration_2 brightness_3 + duration_3 ...". For example: + + echo 0 1000 255 2000 > pattern + + It will make the LED go gradually from zero-intensity to max (255) + intensity in 1000 milliseconds, then back to zero intensity in 2000 + milliseconds: + + LED brightness + ^ + 255-| / \ / \ / + | / \ / \ / + | / \ / \ / + | / \ / \ / + 0-| / \/ \/ + +---0----1----2----3----4----5----6------------> time (s) + + 2. To make the LED go instantly from one brigntess value to another, + we should use use zero-time lengths (the brightness must be same as + the previous tuple's). So the format should be: + "brightness_1 duration_1 brightness_1 0 brightness_2 duration_2 + brightness_2 0 ...". For example: + + echo 0 1000 0 0 255 2000 255 0 > pattern + + It will make the LED stay off for one second, then stay at max brightness + for two seconds: + + LED brightness + ^ + 255-| +---------+ +---------+ + | | | | | + | | | | | + | | | | | + 0-| -----+ +----+ +---- + +---0----1----2----3----4----5----6------------> time (s) + +What: /sys/class/leds/<led>/hw_pattern +Date: September 2018 +KernelVersion: 4.20 +Description: + Specify a hardware pattern for the LED, for LED hardware that + supports autonomously controlling brightness over time, according + to some preprogrammed hardware patterns. It deactivates any active + software pattern. + + Since different LED hardware can have different semantics of + hardware patterns, each driver is expected to provide its own + description for the hardware patterns in their ABI documentation + file. + +What: /sys/class/leds/<led>/repeat +Date: September 2018 +KernelVersion: 4.20 +Description: + Specify a pattern repeat number. -1 means repeat indefinitely, + other negative numbers and number 0 are invalid. + + This file will always return the originally written repeat + number. |