[PATCH v1 1/2] dt-bindings: backlight: Add MPS MP3309C
Flavio Suligoi
f.suligoi at asem.it
Tue Aug 29 10:15:45 UTC 2023
The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
programmable switching frequency to optimize efficiency.
The brightness can be controlled either by I2C commands (called "analog"
mode) or by a PWM input signal (PWM mode).
This driver supports both modes.
For device driver details, please refer to:
- drivers/video/backlight/mp3309c_bl.c
The datasheet is available at:
- https://www.monolithicpower.com/en/mp3309c.html
Signed-off-by: Flavio Suligoi <f.suligoi at asem.it>
---
.../bindings/leds/backlight/mps,mp3309c.yaml | 202 ++++++++++++++++++
1 file changed, 202 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
diff --git a/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
new file mode 100644
index 000000000000..a58904f2a271
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
@@ -0,0 +1,202 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/mps,mp3309c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MPS MP3309C backlight
+
+maintainers:
+ - Flavio Suligoi <f.suligoi at asem.it>
+
+description: |
+ The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
+ programmable switching frequency to optimize efficiency.
+ It supports both analog (via I2C commands) and PWM dimming mode.
+
+ The datasheet is available at:
+ https://www.monolithicpower.com/en/mp3309c.html
+
+properties:
+ compatible:
+ const: mps,mp3309c-backlight
+
+ reg:
+ maxItems: 1
+
+ mps,dimming-mode:
+ description: The dimming mode (PWM or analog by I2C commands).
+ $ref: '/schemas/types.yaml#/definitions/string'
+ enum:
+ - pwm
+ - analog-i2c
+
+ pinctrl-names:
+ items:
+ - const: default
+
+ pinctrl-0: true
+
+ pwms:
+ description: PWM channel used for controlling the backlight in "pwm" dimming
+ mode.
+ maxItems: 1
+
+ default-brightness:
+ minimum: 0
+
+ max-brightness:
+ minimum: 1
+
+ enable-gpios:
+ description: GPIO used to enable the backlight in "analog-i2c" dimming mode.
+ maxItems: 1
+
+ mps,switch-on-delay-ms:
+ description: delay (in ms) before switch on the backlight, to wait for image
+ stabilization.
+ default: 10
+
+ mps,switch-off-delay-ms:
+ description: delay (in ms) after the switch off command to the backlight.
+ default: 0
+
+ mps,overvoltage-protection-13v:
+ description: overvoltage protection set to 13.5V.
+ type: boolean
+ mps,overvoltage-protection-24v:
+ description: overvoltage protection set to 24V.
+ type: boolean
+ mps,overvoltage-protection-35v:
+ description: overvoltage protection set to 35.5V.
+ type: boolean
+
+ mps,reset-gpios:
+ description: optional GPIO to reset an external device (LCD panel, FPGA,
+ etc.) when the backlight is switched on.
+ maxItems: 1
+
+ mps,reset-on-delay-ms:
+ description: delay (in s) before generating the reset-gpios.
+ default: 10
+
+ mps,reset-on-length-ms:
+ description: pulse length (in ms) for reset-gpios.
+ default: 10
+
+oneOf:
+ - required:
+ - mps,overvoltage-protection-13v
+ - required:
+ - mps,overvoltage-protection-24v
+ - required:
+ - mps,overvoltage-protection-35.5v
+
+allOf:
+ - $ref: common.yaml#
+ - if:
+ properties:
+ mps,dimming-mode:
+ contains:
+ enum:
+ - pwm
+ then:
+ required:
+ - pwms
+ not:
+ required:
+ - enable-gpios
+
+ - if:
+ properties:
+ mps,dimming-mode:
+ contains:
+ enum:
+ - analog-i2c
+ then:
+ required:
+ - enable-gpios
+ not:
+ required:
+ - pwms
+
+required:
+ - compatible
+ - reg
+ - mps,dimming-mode
+ - max-brightness
+ - default-brightness
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ i2c3 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ clock-frequency = <100000>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_i2c3>;
+ status = "okay";
+
+ /* Backlight with PWM control */
+ backlight_pwm: backlight at 17 {
+ compatible = "mps,mp3309c-backlight";
+ reg = <0x17>;
+ mps,dimming-mode = "pwm";
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_fpga_reset>;
+ pwms = <&pwm1 0 3333333 0>; /* 300 Hz --> (1/f) * 1*10^9 */
+ max-brightness = <100>;
+ default-brightness = <80>;
+ mps,switch-on-delay-ms = <800>;
+ mps,switch-off-delay-ms = <10>;
+ mps,overvoltage-protection-24v;
+
+ /*
+ * Enable an FPGA reset pulse when MIPI data are stable,
+ * before switch on the backlight
+ */
+ mps,reset-gpios = <&gpio4 20 GPIO_ACTIVE_HIGH>;
+ mps,reset-on-delay-ms = <100>;
+ mps,reset-on-length-ms = <10>;
+ };
+ };
+
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ /* Backlight with analog control via I2C bus */
+ i2c3 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ clock-frequency = <100000>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_i2c3>;
+ status = "okay";
+
+ backlight_analog_i2c: backlight at 18 {
+ compatible = "mps,mp3309c-backlight";
+ reg = <0x17>;
+ mps,dimming-mode = "analog-i2c";
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_reg_pwm_backlight_fixed>,
+ <&pinctrl_fpga_reset>;
+ enable-gpios = <&gpio5 5 GPIO_ACTIVE_HIGH>;
+ max-brightness = <100>;
+ default-brightness = <80>;
+ mps,switch-on-delay-ms = <800>;
+ mps,switch-off-delay-ms = <10>;
+ mps,overvoltage-protection-24v;
+
+ /*
+ * Enable an FPGA reset pulse when MIPI data are stable,
+ * before switch on the backlight
+ */
+ mps,reset-gpios = <&gpio4 20 GPIO_ACTIVE_HIGH>;
+ mps,reset-on-delay-ms = <100>;
+ mps,reset-on-length-ms = <10>;
+ };
+ };
--
2.34.1
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