projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| f797dbf9 CH |
1 | .. SPDX-License-Identifier: GPL-2.0 |
| 2 | ||
| 3 | ========================================= | |
| 4 | The device for Mediatek MT6370 RGB LED | |
| 5 | ========================================= | |
| 6 | ||
| 7 | Description | |
| 8 | ----------- | |
| 9 | ||
| 10 | The MT6370 integrates a four-channel RGB LED driver, designed to provide a | |
| 11 | variety of lighting effect for mobile device applications. The RGB LED devices | |
| 12 | includes a smart LED string controller and it can drive 3 channels of LEDs with | |
| 13 | a sink current up to 24mA and a CHG_VIN power good indicator LED with sink | |
| 14 | current up to 6mA. It provides three operation modes for RGB LEDs: | |
| 15 | PWM Dimming mode, breath pattern mode, and constant current mode. The device | |
| 16 | can increase or decrease the brightness of the RGB LED via an I2C interface. | |
| 17 | ||
| 18 | The breath pattern for a channel can be programmed using the "pattern" trigger, | |
| 19 | using the hw_pattern attribute. | |
| 20 | ||
| 21 | /sys/class/leds/<led>/hw_pattern | |
| 22 | -------------------------------- | |
| 23 | ||
| 24 | Specify a hardware breath pattern for a MT6370 RGB LED. | |
| 25 | ||
| 26 | The breath pattern is a series of timing pairs, with the hold-time expressed in | |
| 27 | milliseconds. And the brightness is controlled by | |
| 28 | '/sys/class/leds/<led>/brightness'. The pattern doesn't include the brightness | |
| 29 | setting. Hardware pattern only controls the timing for each pattern stage | |
| 30 | depending on the current brightness setting. | |
| 31 | ||
| 32 | Pattern diagram:: | |
| 33 | ||
| cc087c0b BS |
34 | "0 Tr1 0 Tr2 0 Tf1 0 Tf2 0 Ton 0 Toff" --> '0' for dummy brightness code |
| 35 | ||
| 36 | ^ | |
| 37 | | ============ | |
| 38 | | / \ / | |
| 39 | Icurr | / \ / | |
| 40 | | / \ / | |
| 41 | | / \ / .....repeat | |
| 42 | | / \ / | |
| 43 | | --- --- --- | |
| 44 | |--- --- --- | |
| 45 | +----------------------------------============------------> Time | |
| 46 | < Tr1><Tr2>< Ton ><Tf1><Tf2 >< Toff >< Tr1><Tr2> | |
| f797dbf9 | 47 | |
| a8fd44cb | 48 | Timing description: |
| f797dbf9 | 49 | |
| a8fd44cb BS |
50 | * Tr1: First rising time for 0% - 30% load. |
| 51 | * Tr2: Second rising time for 31% - 100% load. | |
| 52 | * Ton: On time for 100% load. | |
| 53 | * Tf1: First falling time for 100% - 31% load. | |
| 54 | * Tf2: Second falling time for 30% to 0% load. | |
| 55 | * Toff: Off time for 0% load. | |
| f797dbf9 | 56 | |
| a8fd44cb BS |
57 | * Tr1/Tr2/Tf1/Tf2/Ton: 125ms to 3125ms, 200ms per step. |
| 58 | * Toff: 250ms to 6250ms, 400ms per step. | |
| f797dbf9 CH |
59 | |
| 60 | Pattern example:: | |
| 61 | ||
| 62 | "0 125 0 125 0 125 0 125 0 625 0 1050" | |
| 63 | ||
| 64 | This Will configure Tr1/Tr2/Tf1/Tf2 to 125m, Ton to 625ms, and Toff to 1050ms. |