leds: add new LED driver for TI LP5812

From: Nam Tran <[email protected]>
To: Pavel Machek <[email protected]>, Lee Jones <[email protected]>, Krzysztof Kozlowski <[email protected]>, Rob Herring <[email protected]>, Conor Dooley <[email protected]>
Cc: [email protected], [email protected], [email protected]

This patch series adds support for the Texas Instruments LP5812 LED driver. Patch 1 adds the Device Tree (DT) bindings documentation.
Patch 2 introduces the core driver implementation.

The LP5812 is an I2C-controlled LED driver capable of driving up to 4 LEDs with independent brightness control and pattern programming. This driver provides support through the Linux LED framework and includes device tree bindings for proper integration.

This driver has been tested on Raspberry Pi 4 B using kernel version 6.14.0.

I kindly request feedback from the community to ensure that this driver adheres to the Linux LED subsystem standards.

Thank you for your consideration.

Best regards,
Nam

---

Changes in v2:
- Renamed DT bindings file from leds-lp5812.yaml to ti,lp5812.yaml.
- Added LP5812 device tree node to bcm2711-rpi-4b.dts for Raspberry Pi 4B.
- Updated core driver implementation to fix build errors in kernel version 6.14.0-rc4. (The v1 patch was only compatible with kernel version 6.1.93)

This documentation ensures proper integration of the LP5812 in Device Tree-based systems.

---
 .../devicetree/bindings/leds/ti,lp5812.yaml   | 34 +++++++++++++++++++
 MAINTAINERS                                   |  6 ++++
 2 files changed, 40 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/ti,lp5812.yaml

new file mode 100644
index 000000000000..1eb395230531
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+
+title: LED driver for LP5812 LED from Texas Instruments.
+
+maintainers:
+
+description: |
+  The LP5812 is an I2C LED Driver that can support LED matrix 4x3.
+
+properties:
+  compatible:
+    const: ti,lp5812
+
+  reg:
+    description: I2C slave address
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c1 {
+      lp5812@1b {
+        compatible = "ti,lp5812";
+        reg = <0x1b>;
+      };
+    };
+
+...

index 4ff26fa94895..32312959d595 100644
@@ -23494,6 +23494,12 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/leds/backlight/ti,lp8864.yaml
 F:	drivers/leds/leds-lp8864.c
 
+TEXAS INSTRUMENTS' LP5812 LED DRIVER
+M:	Nam Tran <[email protected]>
+L:	[email protected]
+S:	Maintained
+F:	Documentation/devicetree/bindings/leds/ti,lp5812.yaml
+
 TEXAS INSTRUMENTS' SYSTEM CONTROL INTERFACE (TISCI) PROTOCOL DRIVER
 M:	Nishanth Menon <[email protected]>
 M:	Tero Kristo <[email protected]>

2.25.1

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:
./Documentation/devicetree/bindings/leds/ti,lp5812.yaml:4:1: [error] syntax error: expected '<document start>', but found '<block mapping start>' (syntax) ./Documentation/devicetree/bindings/leds/ti,lp5812.yaml:6:13: [error] empty value in block mapping (empty-values)

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/leds/ti,lp5812.yaml: ignoring, error parsing file ./Documentation/devicetree/bindings/leds/ti,lp5812.yaml:4:1: expected '<document start>', but found ('<block mapping start>',) make[2]: *** Deleting file 'Documentation/devicetree/bindings/leds/ti,lp5812.example.dts' Documentation/devicetree/bindings/leds/ti,lp5812.yaml:4:1: expected '<document start>', but found ('<block mapping start>',) make[2]: *** [Documentation/devicetree/bindings/Makefile:26: Documentation/devicetree/bindings/leds/ti,lp5812.example.dts] Error 1 make[2]: *** Waiting for unfinished jobs....
make[1]: *** [/builds/robherring/dt-review-ci/linux/Makefile:1511: dt_binding_check] Error 2
make: *** [Makefile:251: __sub-make] Error 2

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/[email protected]

The base for the series is generally the latest rc1. A different dependency should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above error(s), then make sure 'yamllint' is installed and dt-schema is up to date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note that DT_SCHEMA_FILES can be set to your schema file to speed up checking your schema. However, it must be unset to test all examples with your schema.

Nothing improved above.

Please read my previous comment and implement it or respond to it, if you disagree.

A nit, subject: drop second/last, redundant "bindings". The "dt-bindings" prefix is already stating that these are bindings. See also:
https://elixir.bootlin.com/linux/v6.7-rc8/source/Documentation/devicetree/bindings/submitting-patches.rst#L18

The chip can drive LED matrix 4x3.
This driver uses I2C to communicate with the chip.

---
 MAINTAINERS                                   |    6 +
 .../arm/boot/dts/broadcom/bcm2711-rpi-4-b.dts |    7 +
 drivers/leds/Kconfig                          |   13 +
 drivers/leds/Makefile                         |    2 +
 drivers/leds/leds-lp5812-common.c             | 1097 ++++++++
 drivers/leds/leds-lp5812-common.h             |  323 +++
 drivers/leds/leds-lp5812-regs.h               |   96 +
 drivers/leds/leds-lp5812.c                    | 2317 +++++++++++++++++
 8 files changed, 3861 insertions(+)
 create mode 100644 drivers/leds/leds-lp5812-common.c
 create mode 100644 drivers/leds/leds-lp5812-common.h
 create mode 100644 drivers/leds/leds-lp5812-regs.h
 create mode 100644 drivers/leds/leds-lp5812.c

index 32312959d595..fabd09eb6c0b 100644
@@ -23499,6 +23499,12 @@ M:	Nam Tran <[email protected]>
 L:	[email protected]
 S:	Maintained
 F:	Documentation/devicetree/bindings/leds/ti,lp5812.yaml
+F:	drivers/leds/Kconfig
+F:	drivers/leds/Makefile
+F:	drivers/leds/leds-lp5812-common.c
+F:	drivers/leds/leds-lp5812-common.h
+F:	drivers/leds/leds-lp5812-regs.h
+F:	drivers/leds/leds-lp5812.c
 
 TEXAS INSTRUMENTS' SYSTEM CONTROL INTERFACE (TISCI) PROTOCOL DRIVER
 M:	Nishanth Menon <[email protected]>

index 353bb50ce542..0d01c6b6a5ba 100644
@@ -270,3 +270,10 @@ &vec {
 &wifi_pwrseq {
 	reset-gpios = <&expgpio 1 GPIO_ACTIVE_LOW>;
 };
+
+&i2c1 {
+	lp5812@1b {
+		compatible = "ti,lp5812";
+		reg = <0x1b>;
+	};
+};

index 2b27d043921c..e43dbd5a4d8c 100644
@@ -483,6 +483,19 @@ config LEDS_LP5569
 	  Driver provides direct control via LED class and interface for
 	  programming the engines.
 
+config LEDS_LP5812
+	bool "Enable LP5812 support LED matrix 4x3"
+	depends on LEDS_CLASS && I2C
+	depends on LEDS_CLASS_MULTICOLOR
+	help
+	  If you say Y here you get support for TI LP5812 LED driver.
+
+	  The LP5812 is an I2C-based RGB LED driver that supports a 4x3 LED matrix.
+	  It provides independent brightness control and color mixing for each LED.
+	  This driver integrates with the Linux LED framework and LED multicolor class.
+
+	  If unsure, say N.
+
 config LEDS_LP8501
 	tristate "LED Support for TI LP8501 LED driver chip"
 	depends on LEDS_CLASS && I2C

index 6ad52e219ec6..2b95463c9ba7 100644
@@ -54,6 +54,8 @@ obj-$(CONFIG_LEDS_LP5523)		+= leds-lp5523.o
 obj-$(CONFIG_LEDS_LP5562)		+= leds-lp5562.o
 obj-$(CONFIG_LEDS_LP5569)		+= leds-lp5569.o
 obj-$(CONFIG_LEDS_LP55XX_COMMON)	+= leds-lp55xx-common.o
+obj-$(CONFIG_LEDS_LP5812) 		+= leds-lp5812.o
+leds-lp5812-objs				:= leds-lp5812.o leds-lp5812-common.o
 obj-$(CONFIG_LEDS_LP8501)		+= leds-lp8501.o
 obj-$(CONFIG_LEDS_LP8788)		+= leds-lp8788.o
 obj-$(CONFIG_LEDS_LP8860)		+= leds-lp8860.o

2.25.1

Part of the diff is not shown here. View the raw message.

You decided to ignore my previous question, but it still valid. Respond to it.

Sorry, if you keep ignoring reviewers, you will not get anywhere.

No, DTS is not part of LED. You cannot combine it in the same patch.

...

My bot found new DTB warnings on the .dts files added or changed in this series.

Some warnings may be from an existing SoC .dtsi. Or perhaps the warnings are fixed by another series. Ultimately, it is up to the platform maintainer whether these warnings are acceptable or not. No need to reply unless the platform maintainer has comments.

If you already ran DT checks and didn't see these error(s), then make sure dt-schema is up to date:

  pip3 install dtschema --upgrade

New warnings running 'make CHECK_DTBS=y for arch/arm/boot/dts/broadcom/' for [email protected]:

arch/arm/boot/dts/broadcom/bcm2711-rpi-400.dtb: /soc/i2c@7e804000/lp5812@1b: failed to match any schema with compatible: ['ti,lp5812'] arch/arm/boot/dts/broadcom/bcm2711-rpi-4-b.dtb: /soc/i2c@7e804000/lp5812@1b: failed to match any schema with compatible: ['ti,lp5812']