65 lines
2.5 KiB
ReStructuredText
65 lines
2.5 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
|
|
|
|
=========================================
|
|
The device for Mediatek MT6370 RGB LED
|
|
=========================================
|
|
|
|
Description
|
|
-----------
|
|
|
|
The MT6370 integrates a four-channel RGB LED driver, designed to provide a
|
|
variety of lighting effect for mobile device applications. The RGB LED devices
|
|
includes a smart LED string controller and it can drive 3 channels of LEDs with
|
|
a sink current up to 24mA and a CHG_VIN power good indicator LED with sink
|
|
current up to 6mA. It provides three operation modes for RGB LEDs:
|
|
PWM Dimming mode, breath pattern mode, and constant current mode. The device
|
|
can increase or decrease the brightness of the RGB LED via an I2C interface.
|
|
|
|
The breath pattern for a channel can be programmed using the "pattern" trigger,
|
|
using the hw_pattern attribute.
|
|
|
|
/sys/class/leds/<led>/hw_pattern
|
|
--------------------------------
|
|
|
|
Specify a hardware breath pattern for a MT6370 RGB LED.
|
|
|
|
The breath pattern is a series of timing pairs, with the hold-time expressed in
|
|
milliseconds. And the brightness is controlled by
|
|
'/sys/class/leds/<led>/brightness'. The pattern doesn't include the brightness
|
|
setting. Hardware pattern only controls the timing for each pattern stage
|
|
depending on the current brightness setting.
|
|
|
|
Pattern diagram::
|
|
|
|
"0 Tr1 0 Tr2 0 Tf1 0 Tf2 0 Ton 0 Toff" --> '0' for dummy brightness code
|
|
|
|
^
|
|
| ============
|
|
| / \ /
|
|
Icurr | / \ /
|
|
| / \ /
|
|
| / \ / .....repeat
|
|
| / \ /
|
|
| --- --- ---
|
|
|--- --- ---
|
|
+----------------------------------============------------> Time
|
|
< Tr1><Tr2>< Ton ><Tf1><Tf2 >< Toff >< Tr1><Tr2>
|
|
|
|
Timing description:
|
|
|
|
* Tr1: First rising time for 0% - 30% load.
|
|
* Tr2: Second rising time for 31% - 100% load.
|
|
* Ton: On time for 100% load.
|
|
* Tf1: First falling time for 100% - 31% load.
|
|
* Tf2: Second falling time for 30% to 0% load.
|
|
* Toff: Off time for 0% load.
|
|
|
|
* Tr1/Tr2/Tf1/Tf2/Ton: 125ms to 3125ms, 200ms per step.
|
|
* Toff: 250ms to 6250ms, 400ms per step.
|
|
|
|
Pattern example::
|
|
|
|
"0 125 0 125 0 125 0 125 0 625 0 1050"
|
|
|
|
This Will configure Tr1/Tr2/Tf1/Tf2 to 125m, Ton to 625ms, and Toff to 1050ms.
|