[PATCH v8 4/5] docs: auxdisplay: document TI LP5812 RGB LED driver

Nam Tran trannamatk at gmail.com
Sun Apr 27 01:24:46 PDT 2025


The driver provides sysfs interfaces to control
and configure the LP5812 device and its LED channels.

The documetation describes the chip's capabilities,
sysfs interface, and usage examples.

Signed-off-by: Nam Tran <trannamatk at gmail.com>
---
 .../admin-guide/auxdisplay/index.rst          |  3 +-
 .../admin-guide/auxdisplay/lp5812.rst         | 79 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 3 files changed, 82 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/admin-guide/auxdisplay/lp5812.rst

diff --git a/Documentation/admin-guide/auxdisplay/index.rst b/Documentation/admin-guide/auxdisplay/index.rst
index e466f0595248..5d627f067c77 100644
--- a/Documentation/admin-guide/auxdisplay/index.rst
+++ b/Documentation/admin-guide/auxdisplay/index.rst
@@ -5,8 +5,9 @@ Auxiliary Display Support
 .. toctree::
     :maxdepth: 1
 
-    ks0108.rst
     cfag12864b.rst
+    ks0108.rst
+    lp5812.rst
 
 .. only::  subproject and html
 
diff --git a/Documentation/admin-guide/auxdisplay/lp5812.rst b/Documentation/admin-guide/auxdisplay/lp5812.rst
new file mode 100644
index 000000000000..58d716f899d1
--- /dev/null
+++ b/Documentation/admin-guide/auxdisplay/lp5812.rst
@@ -0,0 +1,79 @@
+========================
+Kernel driver for lp5812
+========================
+
+* TI/National Semiconductor LP5812 LED Driver
+* Datasheet: https://www.ti.com/product/LP5812#tech-docs
+
+Authors: Jared Zhou <jared-zhou at ti.com>
+
+Description
+===========
+
+The LP5812 is a 4x3 matrix LED driver with support for both manual and
+autonomous animation control. It provides features such as:
+
+- PWM dimming and DC current control
+- Slope time configuration
+- Autonomous Engine Unit (AEU) for LED animation playback
+- Flexible scan and drive mode configuration
+
+This driver provides sysfs interfaces to control and configure the LP5812
+device and its LED channels.
+
+Sysfs Interface
+===============
+
+LP5812 device exposes a chip-level sysfs group:
+  /sys/bus/i2c/devices/<i2c-dev-addr>/lp5812_chip_setup/
+
+The following attributes are available at chip level:
+  - device_enable: Enable/disable the device (RW)
+  - dev_config: Configure drive mode and scan order (RW)
+  - device_command: Issue device-wide commands (WO)
+  - sw_reset: Reset the hardware (WO)
+  - fault_clear: Clear any device faults (WO)
+  - tsd_config_status: Read thermal shutdown config status (RO)
+
+Each LED channel is exposed as:
+  /sys/bus/i2c/devices/<i2c-dev-addr>/led_<id>/
+
+Each LED exposes the following attributes:
+  - activate: Activate or deactivate the LED (RW)
+  - mode: manual or autonomous mode (RW)
+  - manual_dc: DC current value (0–255) (RW)
+  - manual_pwm: PWM duty cycle (0–255) (RW)
+  - autonomous_dc: DC current in autonomous mode (RW)
+  - pwm_dimming_scale: linear or exponential (RW)
+  - pwm_phase_align: PWM alignment mode (RW)
+  - autonomous_animation: Config autonomous animation mode with aeu number, start pause time, stop pause time, playback time (RW)
+  - aep_status: autonomous engine pattern status (RO)
+  - auto_pwm_val: pwm value in autonomous mode when pause the animation (RO)
+  - lod_lsd: lod and lsd fault detected status (RO)
+
+Example Usage
+=============
+
+To control led_A0 in manual mode::
+    echo 1 > /sys/bus/i2c/drivers/lp5812/xxxx/lp5812_chip_setup/device_enable
+    echo 1 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/activate
+    echo manual > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/mode
+    echo 100 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/manual_dc
+    echo 100 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/manual_pwm
+
+To control led_A0 in autonomous mode::
+    echo 1 > /sys/bus/i2c/drivers/lp5812/xxxx/lp5812_chip_setup/device_enable
+    echo 1 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/activate
+    echo autonomous > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/mode
+    echo 1:10:10:15 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/autonomous_animation
+    echo 100 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/AEU1/pwm1
+    echo 100 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/AEU1/pwm2
+    echo 100 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/AEU1/pwm3
+    echo 100 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/AEU1/pwm4
+    echo 100 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/AEU1/pwm5
+    echo 5 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/AEU1/slope_time_t1
+    echo 5 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/AEU1/slope_time_t2
+    echo 5 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/AEU1/slope_time_t3
+    echo 5 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/AEU1/slope_time_t4
+    echo 1 > /sys/bus/i2c/drivers/lp5812/xxxx/led_A0/AEU1/playback_time
+    echo start > /sys/bus/i2c/drivers/lp5812/xxxx/lp5812_chip_setup/device_command
diff --git a/MAINTAINERS b/MAINTAINERS
index 5d8ee0801c69..dd504dee3274 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -24021,6 +24021,7 @@ M:	Nam Tran <trannamatk at gmail.com>
 L:	linux-kernel at vger.kernel.org
 S:	Maintained
 F:	Documentation/ABI/testing/sysfs-bus-i2c-devices-lp5812
+F:	Documentation/admin-guide/auxdisplay/lp5812.rst
 F:	Documentation/devicetree/bindings/auxdisplay/ti,lp5812.yaml
 F:	drivers/auxdisplay/Kconfig
 F:	drivers/auxdisplay/Makefile
-- 
2.25.1




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