diff options
5 files changed, 120 insertions, 31 deletions
diff --git a/Documentation/devicetree/bindings/leds/backlight/common.yaml b/Documentation/devicetree/bindings/leds/backlight/common.yaml index 3b60afbab68b..e0983e44934c 100644 --- a/Documentation/devicetree/bindings/leds/backlight/common.yaml +++ b/Documentation/devicetree/bindings/leds/backlight/common.yaml @@ -33,4 +33,21 @@ properties: due to restrictions in a specific system, such as mounting conditions. $ref: /schemas/types.yaml#/definitions/uint32 + brightness-levels: + description: + Array of distinct brightness levels. The levels must be in the range + accepted by the underlying LED device. Typically these are in the range + from 0 to 255, but any range starting at 0 will do, as long as they are + accepted by the LED. + The 0 value means a 0% of brightness (darkest/off), while the last value + in the array represents a full 100% brightness (brightest). + If this array is not provided, the driver default mapping is used. + $ref: /schemas/types.yaml#/definitions/uint32-array + + default-brightness-level: + description: + The default brightness level (index into the array defined by the + "brightness-levels" property). + $ref: /schemas/types.yaml#/definitions/uint32 + additionalProperties: true diff --git a/Documentation/devicetree/bindings/leds/backlight/led-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/led-backlight.yaml index d7b78198abc2..f5554da6bc6c 100644 --- a/Documentation/devicetree/bindings/leds/backlight/led-backlight.yaml +++ b/Documentation/devicetree/bindings/leds/backlight/led-backlight.yaml @@ -16,6 +16,9 @@ description: can also be used to describe a backlight device controlled by the output of a LED driver. +allOf: + - $ref: common.yaml# + properties: compatible: const: led-backlight @@ -26,25 +29,11 @@ properties: items: maxItems: 1 - brightness-levels: - description: - Array of distinct brightness levels. The levels must be in the range - accepted by the underlying LED devices. This is used to translate a - backlight brightness level into a LED brightness level. If it is not - provided, the identity mapping is used. - $ref: /schemas/types.yaml#/definitions/uint32-array - - default-brightness-level: - description: - The default brightness level (index into the array defined by the - "brightness-levels" property). - $ref: /schemas/types.yaml#/definitions/uint32 - required: - compatible - leds -additionalProperties: false +unevaluatedProperties: false examples: - | diff --git a/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml new file mode 100644 index 000000000000..4191e33626f5 --- /dev/null +++ b/Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml @@ -0,0 +1,73 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$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@asem.it> + +description: | + The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a + programmable switching frequency to optimize efficiency. + It supports two different dimming modes: + + - analog mode, via I2C commands (default) + - PWM controlled mode. + + The datasheet is available at: + https://www.monolithicpower.com/en/mp3309c.html + +allOf: + - $ref: common.yaml# + +properties: + compatible: + const: mps,mp3309c + + reg: + maxItems: 1 + + pwms: + description: if present, the backlight is controlled in PWM mode. + maxItems: 1 + + enable-gpios: + description: GPIO used to enable the backlight in "analog-i2c" dimming mode. + maxItems: 1 + + mps,overvoltage-protection-microvolt: + description: Overvoltage protection (13.5V, 24V or 35.5V). + enum: [ 13500000, 24000000, 35500000 ] + default: 35500000 + + mps,no-sync-mode: + description: disable synchronous rectification mode + type: boolean + +required: + - compatible + - reg + - max-brightness + - default-brightness + +unevaluatedProperties: false + +examples: + - | + i2c { + #address-cells = <1>; + #size-cells = <0>; + + /* Backlight with PWM control */ + backlight_pwm: backlight@17 { + compatible = "mps,mp3309c"; + reg = <0x17>; + pwms = <&pwm1 0 3333333 0>; /* 300 Hz --> (1/f) * 1*10^9 */ + max-brightness = <100>; + default-brightness = <80>; + mps,overvoltage-protection-microvolt = <24000000>; + }; + }; diff --git a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.yaml index 535690288990..b71f6454a4ac 100644 --- a/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.yaml +++ b/Documentation/devicetree/bindings/leds/backlight/pwm-backlight.yaml @@ -11,6 +11,9 @@ maintainers: - Daniel Thompson <daniel.thompson@linaro.org> - Jingoo Han <jingoohan1@gmail.com> +allOf: + - $ref: common.yaml# + properties: compatible: const: pwm-backlight @@ -39,21 +42,6 @@ properties: Delay in ms between disabling the backlight using GPIO and setting PWM value to 0. - brightness-levels: - description: - Array of distinct brightness levels. Typically these are in the range - from 0 to 255, but any range starting at 0 will do. The actual brightness - level (PWM duty cycle) will be interpolated from these values. 0 means a - 0% duty cycle (darkest/off), while the last value in the array represents - a 100% duty cycle (brightest). - $ref: /schemas/types.yaml#/definitions/uint32-array - - default-brightness-level: - description: - The default brightness level (index into the array defined by the - "brightness-levels" property). - $ref: /schemas/types.yaml#/definitions/uint32 - num-interpolated-steps: description: Number of interpolated steps between each value of brightness-levels @@ -69,7 +57,7 @@ required: - compatible - pwms -additionalProperties: false +unevaluatedProperties: false examples: - | diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index a51fbab96368..289bd9ce4d36 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -626,9 +626,14 @@ static void pwm_backlight_remove(struct platform_device *pdev) { struct backlight_device *bl = platform_get_drvdata(pdev); struct pwm_bl_data *pb = bl_get_data(bl); + struct pwm_state state; backlight_device_unregister(bl); pwm_backlight_power_off(pb); + pwm_get_state(pb->pwm, &state); + state.duty_cycle = 0; + state.enabled = false; + pwm_apply_state(pb->pwm, &state); if (pb->exit) pb->exit(&pdev->dev); @@ -638,8 +643,13 @@ static void pwm_backlight_shutdown(struct platform_device *pdev) { struct backlight_device *bl = platform_get_drvdata(pdev); struct pwm_bl_data *pb = bl_get_data(bl); + struct pwm_state state; pwm_backlight_power_off(pb); + pwm_get_state(pb->pwm, &state); + state.duty_cycle = 0; + state.enabled = false; + pwm_apply_state(pb->pwm, &state); } #ifdef CONFIG_PM_SLEEP @@ -647,12 +657,24 @@ static int pwm_backlight_suspend(struct device *dev) { struct backlight_device *bl = dev_get_drvdata(dev); struct pwm_bl_data *pb = bl_get_data(bl); + struct pwm_state state; if (pb->notify) pb->notify(pb->dev, 0); pwm_backlight_power_off(pb); + /* + * Note that disabling the PWM doesn't guarantee that the output stays + * at its inactive state. However without the PWM disabled, the PWM + * driver refuses to suspend. So disable here even though this might + * enable the backlight on poorly designed boards. + */ + pwm_get_state(pb->pwm, &state); + state.duty_cycle = 0; + state.enabled = false; + pwm_apply_state(pb->pwm, &state); + if (pb->notify_after) pb->notify_after(pb->dev, 0); |