Lines Matching +full:led +full:- +full:pattern

1 .. SPDX-License-Identifier: GPL-2.0
8 -----------
11 number of PWM channels, a programmable pattern lookup table and a RGB LED
23 deeper idle states the LPG provides pattern support. This consists of a shared
25 range within the table to use, the rate and if the pattern should repeat.
27 The pattern for a channel can be programmed using the "pattern" trigger, using
30 /sys/class/leds/<led>/hw_pattern
31 --------------------------------
33 Specify a hardware pattern for a Qualcomm LPG LED.
35 The pattern is a series of brightness and hold-time pairs, with the hold-time
36 expressed in milliseconds. The hold time is a property of the pattern and must
37 therefor be identical for each element in the pattern (except for the pauses
39 transitions expected by the leds-trigger-pattern format, each entry in the
40 pattern must be followed a zero-length entry of the same brightness.
42 Simple pattern::
48     255 +----+    +----+
50       0 |    +----+    +----
51         +---------------------->
54 The LPG supports specifying a longer hold-time for the first and last element
55 in the pattern, the so called "low pause" and "high pause".
57 Low-pause pattern::
63     255 +--------+    +----+    +----+    +--------+
65       0 |        +----+    +----+    +----+        +----
66         +----------------------------->
69 Similarily, the last entry can be stretched by using a higher hold-time on the
72 In order to save space in the shared lookup table the LPG supports "ping-pong"
73 mode, in which case each run through the pattern is performed by first running
74 the pattern forward, then backwards. This mode is automatically used by the
75 driver when the given pattern is a palindrome. In this case the "high pause"
76 denotes the wait time before the pattern is run in reverse and as such the
77 specified hold-time of the middle item in the pattern is allowed to have a
78 different hold-time.