| Mauro Carvalho Chehab | 26a0755 | 2020-10-30 08:40:57 +0100 | [diff] [blame] | 1 | .. SPDX-License-Identifier: GPL-2.0 |
| 2 | |
| 3 | =================================== |
| 4 | Kernel driver for Spreadtrum SC27XX |
| 5 | =================================== |
| 6 | |
| 7 | /sys/class/leds/<led>/hw_pattern |
| 8 | -------------------------------- |
| 9 | |
| 10 | Specify a hardware pattern for the SC27XX LED. For the SC27XX |
| 11 | LED controller, it only supports 4 stages to make a single |
| 12 | hardware pattern, which is used to configure the rise time, |
| 13 | high time, fall time and low time for the breathing mode. |
| 14 | |
| 15 | For the breathing mode, the SC27XX LED only expects one brightness |
| 16 | for the high stage. To be compatible with the hardware pattern |
| 17 | format, we should set brightness as 0 for rise stage, fall |
| 18 | stage and low stage. |
| 19 | |
| 20 | - Min stage duration: 125 ms |
| 21 | - Max stage duration: 31875 ms |
| 22 | |
| 23 | Since the stage duration step is 125 ms, the duration should be |
| 24 | a multiplier of 125, like 125ms, 250ms, 375ms, 500ms ... 31875ms. |
| 25 | |
| 26 | Thus the format of the hardware pattern values should be: |
| 27 | "0 rise_duration brightness high_duration 0 fall_duration 0 low_duration". |