[PATCH v4 0/2] ARM: dts: sun6i: hummingbird-a31: Enable display output through VGA bridge

[PATCH v4 0/2] ARM: dts: sun6i: hummingbird-a31: Enable display output through VGA bridge

[Chen-Yu Tsai]

Hi,

This is v4 of my sun6i DRM/KMS display enablement series. It adds
regulator support to the dumb-vga-dac bridge and enables the VGA
output on the A31 Hummingbird.


Changes since v3:

  - Add Rob's Ack.

  - Fix up enable/disable callbacks as Archit suggested.

  - Dropped pinmux settings for GPIO pin.

Changes since v2:

  - Changed the enable-gpio of dumb-vga-dac to vdd-supply regulator.
    This better matches the hardware that I have: the DAC has a fixed
    regulator dropping the voltage from the board-wide 5V to 3.3V the
    DAC uses. The regulator is controlled through a GPIO pin.

  - Renamed the node of the VGA connector from "vga" to "vga-connector".

  - Renamed the node of the VGA DAC from "bridge" to "vga-dac".


Regards
ChenYu


Chen-Yu Tsai (2):
  drm/bridge: dumb-vga-dac: Support a VDD regulator supply
  ARM: dts: sun6i: hummingbird-a31: Enable display output through VGA
    bridge

 .../bindings/display/bridge/dumb-vga-dac.txt       |  2 +
 arch/arm/boot/dts/sun6i-a31-hummingbird.dts        | 67 ++++++++++++++++++++++
 drivers/gpu/drm/bridge/dumb-vga-dac.c              | 35 +++++++++++
 3 files changed, 104 insertions(+)

-- 
2.10.2

[PATCH v4 1/2] drm/bridge: dumb-vga-dac: Support a VDD regulator supply

[Chen-Yu Tsai]

Some dumb VGA DACs are active components which require external power.
Add support for specifying a regulator as its power supply.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../bindings/display/bridge/dumb-vga-dac.txt       |  2 ++
 drivers/gpu/drm/bridge/dumb-vga-dac.c              | 35 ++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
index 003bc246a270..164cbb15f04c 100644
--- a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
+++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
@@ -16,6 +16,8 @@ graph bindings specified in Documentation/devicetree/bindings/graph.txt.
 - Video port 0 for RGB input
 - Video port 1 for VGA output
 
+Optional properties:
+- vdd-supply: Power supply for DAC
 
 Example
 -------
diff --git a/drivers/gpu/drm/bridge/dumb-vga-dac.c b/drivers/gpu/drm/bridge/dumb-vga-dac.c
index afec232185a7..15b549f94307 100644
--- a/drivers/gpu/drm/bridge/dumb-vga-dac.c
+++ b/drivers/gpu/drm/bridge/dumb-vga-dac.c
@@ -12,6 +12,7 @@
 
 #include <linux/module.h>
 #include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
 
 #include <drm/drmP.h>
 #include <drm/drm_atomic_helper.h>
@@ -23,6 +24,7 @@ struct dumb_vga {
 	struct drm_connector	connector;
 
 	struct i2c_adapter	*ddc;
+	struct regulator	*vdd;
 };
 
 static inline struct dumb_vga *
@@ -124,8 +126,32 @@ static int dumb_vga_attach(struct drm_bridge *bridge)
 	return 0;
 }
 
+static void dumb_vga_enable(struct drm_bridge *bridge)
+{
+	struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
+	int ret = 0;
+
+	if (vga->vdd)
+		ret = regulator_enable(vga->vdd);
+
+	if (ret) {
+		DRM_ERROR("Failed to enable vdd regulator: %d\n", ret);
+		return;
+	}
+}
+
+static void dumb_vga_disable(struct drm_bridge *bridge)
+{
+	struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
+
+	if (vga->vdd)
+		regulator_disable(vga->vdd);
+}
+
 static const struct drm_bridge_funcs dumb_vga_bridge_funcs = {
 	.attach		= dumb_vga_attach,
+	.enable		= dumb_vga_enable,
+	.disable	= dumb_vga_disable,
 };
 
 static struct i2c_adapter *dumb_vga_retrieve_ddc(struct device *dev)
@@ -169,6 +195,15 @@ static int dumb_vga_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	platform_set_drvdata(pdev, vga);
 
+	vga->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
+	if (IS_ERR(vga->vdd)) {
+		ret = PTR_ERR(vga->vdd);
+		if (ret == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		vga->vdd = NULL;
+		dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret);
+	}
+
 	vga->ddc = dumb_vga_retrieve_ddc(&pdev->dev);
 	if (IS_ERR(vga->ddc)) {
 		if (PTR_ERR(vga->ddc) == -ENODEV) {
-- 
2.10.2

Re: [PATCH v4 1/2] drm/bridge: dumb-vga-dac: Support a VDD regulator supply

[Archit Taneja]

Hi,

Thanks for the patch.

On 11/16/2016 09:12 PM, Chen-Yu Tsai wrote:
> Some dumb VGA DACs are active components which require external power.
> Add support for specifying a regulator as its power supply.
>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> Acked-by: Rob Herring <robh@kernel.org>
> ---
>  .../bindings/display/bridge/dumb-vga-dac.txt       |  2 ++
>  drivers/gpu/drm/bridge/dumb-vga-dac.c              | 35 ++++++++++++++++++++++
>  2 files changed, 37 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
> index 003bc246a270..164cbb15f04c 100644
> --- a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
> +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
> @@ -16,6 +16,8 @@ graph bindings specified in Documentation/devicetree/bindings/graph.txt.
>  - Video port 0 for RGB input
>  - Video port 1 for VGA output
>
> +Optional properties:
> +- vdd-supply: Power supply for DAC
>
>  Example
>  -------
> diff --git a/drivers/gpu/drm/bridge/dumb-vga-dac.c b/drivers/gpu/drm/bridge/dumb-vga-dac.c
> index afec232185a7..15b549f94307 100644
> --- a/drivers/gpu/drm/bridge/dumb-vga-dac.c
> +++ b/drivers/gpu/drm/bridge/dumb-vga-dac.c
> @@ -12,6 +12,7 @@
>
>  #include <linux/module.h>
>  #include <linux/of_graph.h>
> +#include <linux/regulator/consumer.h>
>
>  #include <drm/drmP.h>
>  #include <drm/drm_atomic_helper.h>
> @@ -23,6 +24,7 @@ struct dumb_vga {
>  	struct drm_connector	connector;
>
>  	struct i2c_adapter	*ddc;
> +	struct regulator	*vdd;
>  };
>
>  static inline struct dumb_vga *
> @@ -124,8 +126,32 @@ static int dumb_vga_attach(struct drm_bridge *bridge)
>  	return 0;
>  }
>
> +static void dumb_vga_enable(struct drm_bridge *bridge)
> +{
> +	struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
> +	int ret = 0;
> +
> +	if (vga->vdd)
> +		ret = regulator_enable(vga->vdd);
> +
> +	if (ret) {
> +		DRM_ERROR("Failed to enable vdd regulator: %d\n", ret);
> +		return;

We don't need this return for now. If you're okay with it, can I fix this
and queue to misc?

Thanks,
Archit

> +	}
> +}
> +
> +static void dumb_vga_disable(struct drm_bridge *bridge)
> +{
> +	struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
> +
> +	if (vga->vdd)
> +		regulator_disable(vga->vdd);
> +}
> +
>  static const struct drm_bridge_funcs dumb_vga_bridge_funcs = {
>  	.attach		= dumb_vga_attach,
> +	.enable		= dumb_vga_enable,
> +	.disable	= dumb_vga_disable,
>  };
>
>  static struct i2c_adapter *dumb_vga_retrieve_ddc(struct device *dev)
> @@ -169,6 +195,15 @@ static int dumb_vga_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  	platform_set_drvdata(pdev, vga);
>
> +	vga->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
> +	if (IS_ERR(vga->vdd)) {
> +		ret = PTR_ERR(vga->vdd);
> +		if (ret == -EPROBE_DEFER)
> +			return -EPROBE_DEFER;
> +		vga->vdd = NULL;
> +		dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret);
> +	}
> +
>  	vga->ddc = dumb_vga_retrieve_ddc(&pdev->dev);
>  	if (IS_ERR(vga->ddc)) {
>  		if (PTR_ERR(vga->ddc) == -ENODEV) {
>

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH v4 1/2] drm/bridge: dumb-vga-dac: Support a VDD regulator supply

[Chen-Yu Tsai]

On Thu, Nov 17, 2016 at 3:48 PM, Archit Taneja <architt@codeaurora.org> wrote:
> Hi,
>
> Thanks for the patch.
>
>
> On 11/16/2016 09:12 PM, Chen-Yu Tsai wrote:
>>
>> Some dumb VGA DACs are active components which require external power.
>> Add support for specifying a regulator as its power supply.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> Acked-by: Rob Herring <robh@kernel.org>
>> ---
>>  .../bindings/display/bridge/dumb-vga-dac.txt       |  2 ++
>>  drivers/gpu/drm/bridge/dumb-vga-dac.c              | 35
>> ++++++++++++++++++++++
>>  2 files changed, 37 insertions(+)
>>
>> diff --git
>> a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
>> b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
>> index 003bc246a270..164cbb15f04c 100644
>> --- a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
>> +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
>> @@ -16,6 +16,8 @@ graph bindings specified in
>> Documentation/devicetree/bindings/graph.txt.
>>  - Video port 0 for RGB input
>>  - Video port 1 for VGA output
>>
>> +Optional properties:
>> +- vdd-supply: Power supply for DAC
>>
>>  Example
>>  -------
>> diff --git a/drivers/gpu/drm/bridge/dumb-vga-dac.c
>> b/drivers/gpu/drm/bridge/dumb-vga-dac.c
>> index afec232185a7..15b549f94307 100644
>> --- a/drivers/gpu/drm/bridge/dumb-vga-dac.c
>> +++ b/drivers/gpu/drm/bridge/dumb-vga-dac.c
>> @@ -12,6 +12,7 @@
>>
>>  #include <linux/module.h>
>>  #include <linux/of_graph.h>
>> +#include <linux/regulator/consumer.h>
>>
>>  #include <drm/drmP.h>
>>  #include <drm/drm_atomic_helper.h>
>> @@ -23,6 +24,7 @@ struct dumb_vga {
>>         struct drm_connector    connector;
>>
>>         struct i2c_adapter      *ddc;
>> +       struct regulator        *vdd;
>>  };
>>
>>  static inline struct dumb_vga *
>> @@ -124,8 +126,32 @@ static int dumb_vga_attach(struct drm_bridge *bridge)
>>         return 0;
>>  }
>>
>> +static void dumb_vga_enable(struct drm_bridge *bridge)
>> +{
>> +       struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
>> +       int ret = 0;
>> +
>> +       if (vga->vdd)
>> +               ret = regulator_enable(vga->vdd);
>> +
>> +       if (ret) {
>> +               DRM_ERROR("Failed to enable vdd regulator: %d\n", ret);
>> +               return;
>
>
> We don't need this return for now. If you're okay with it, can I fix this
> and queue to misc?

Yes, please!

Thanks
ChenYu

>
> Thanks,
> Archit
>
>
>> +       }
>> +}
>> +
>> +static void dumb_vga_disable(struct drm_bridge *bridge)
>> +{
>> +       struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
>> +
>> +       if (vga->vdd)
>> +               regulator_disable(vga->vdd);
>> +}
>> +
>>  static const struct drm_bridge_funcs dumb_vga_bridge_funcs = {
>>         .attach         = dumb_vga_attach,
>> +       .enable         = dumb_vga_enable,
>> +       .disable        = dumb_vga_disable,
>>  };
>>
>>  static struct i2c_adapter *dumb_vga_retrieve_ddc(struct device *dev)
>> @@ -169,6 +195,15 @@ static int dumb_vga_probe(struct platform_device
>> *pdev)
>>                 return -ENOMEM;
>>         platform_set_drvdata(pdev, vga);
>>
>> +       vga->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
>> +       if (IS_ERR(vga->vdd)) {
>> +               ret = PTR_ERR(vga->vdd);
>> +               if (ret == -EPROBE_DEFER)
>> +                       return -EPROBE_DEFER;
>> +               vga->vdd = NULL;
>> +               dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret);
>> +       }
>> +
>>         vga->ddc = dumb_vga_retrieve_ddc(&pdev->dev);
>>         if (IS_ERR(vga->ddc)) {
>>                 if (PTR_ERR(vga->ddc) == -ENODEV) {
>>
>
> --
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> a Linux Foundation Collaborative Project

Re: [PATCH v4 1/2] drm/bridge: dumb-vga-dac: Support a VDD regulator supply

[Archit Taneja]

On 11/17/2016 01:25 PM, Chen-Yu Tsai wrote:
> On Thu, Nov 17, 2016 at 3:48 PM, Archit Taneja <architt@codeaurora.org> wrote:
>> Hi,
>>
>> Thanks for the patch.
>>
>>
>> On 11/16/2016 09:12 PM, Chen-Yu Tsai wrote:
>>>
>>> Some dumb VGA DACs are active components which require external power.
>>> Add support for specifying a regulator as its power supply.
>>>
>>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>>> Acked-by: Rob Herring <robh@kernel.org>
>>> ---
>>>  .../bindings/display/bridge/dumb-vga-dac.txt       |  2 ++
>>>  drivers/gpu/drm/bridge/dumb-vga-dac.c              | 35
>>> ++++++++++++++++++++++
>>>  2 files changed, 37 insertions(+)
>>>
>>> diff --git
>>> a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
>>> b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
>>> index 003bc246a270..164cbb15f04c 100644
>>> --- a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
>>> +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
>>> @@ -16,6 +16,8 @@ graph bindings specified in
>>> Documentation/devicetree/bindings/graph.txt.
>>>  - Video port 0 for RGB input
>>>  - Video port 1 for VGA output
>>>
>>> +Optional properties:
>>> +- vdd-supply: Power supply for DAC
>>>
>>>  Example
>>>  -------
>>> diff --git a/drivers/gpu/drm/bridge/dumb-vga-dac.c
>>> b/drivers/gpu/drm/bridge/dumb-vga-dac.c
>>> index afec232185a7..15b549f94307 100644
>>> --- a/drivers/gpu/drm/bridge/dumb-vga-dac.c
>>> +++ b/drivers/gpu/drm/bridge/dumb-vga-dac.c
>>> @@ -12,6 +12,7 @@
>>>
>>>  #include <linux/module.h>
>>>  #include <linux/of_graph.h>
>>> +#include <linux/regulator/consumer.h>
>>>
>>>  #include <drm/drmP.h>
>>>  #include <drm/drm_atomic_helper.h>
>>> @@ -23,6 +24,7 @@ struct dumb_vga {
>>>         struct drm_connector    connector;
>>>
>>>         struct i2c_adapter      *ddc;
>>> +       struct regulator        *vdd;
>>>  };
>>>
>>>  static inline struct dumb_vga *
>>> @@ -124,8 +126,32 @@ static int dumb_vga_attach(struct drm_bridge *bridge)
>>>         return 0;
>>>  }
>>>
>>> +static void dumb_vga_enable(struct drm_bridge *bridge)
>>> +{
>>> +       struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
>>> +       int ret = 0;
>>> +
>>> +       if (vga->vdd)
>>> +               ret = regulator_enable(vga->vdd);
>>> +
>>> +       if (ret) {
>>> +               DRM_ERROR("Failed to enable vdd regulator: %d\n", ret);
>>> +               return;
>>
>>
>> We don't need this return for now. If you're okay with it, can I fix this
>> and queue to misc?
>
> Yes, please!

pushed to drm-misc.

Thanks,
Archit

>
> Thanks
> ChenYu
>
>>
>> Thanks,
>> Archit
>>
>>
>>> +       }
>>> +}
>>> +
>>> +static void dumb_vga_disable(struct drm_bridge *bridge)
>>> +{
>>> +       struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
>>> +
>>> +       if (vga->vdd)
>>> +               regulator_disable(vga->vdd);
>>> +}
>>> +
>>>  static const struct drm_bridge_funcs dumb_vga_bridge_funcs = {
>>>         .attach         = dumb_vga_attach,
>>> +       .enable         = dumb_vga_enable,
>>> +       .disable        = dumb_vga_disable,
>>>  };
>>>
>>>  static struct i2c_adapter *dumb_vga_retrieve_ddc(struct device *dev)
>>> @@ -169,6 +195,15 @@ static int dumb_vga_probe(struct platform_device
>>> *pdev)
>>>                 return -ENOMEM;
>>>         platform_set_drvdata(pdev, vga);
>>>
>>> +       vga->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
>>> +       if (IS_ERR(vga->vdd)) {
>>> +               ret = PTR_ERR(vga->vdd);
>>> +               if (ret == -EPROBE_DEFER)
>>> +                       return -EPROBE_DEFER;
>>> +               vga->vdd = NULL;
>>> +               dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret);
>>> +       }
>>> +
>>>         vga->ddc = dumb_vga_retrieve_ddc(&pdev->dev);
>>>         if (IS_ERR(vga->ddc)) {
>>>                 if (PTR_ERR(vga->ddc) == -ENODEV) {
>>>
>>
>> --
>> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
>> a Linux Foundation Collaborative Project

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v4 2/2] ARM: dts: sun6i: hummingbird-a31: Enable display output through VGA bridge

[Chen-Yu Tsai]

The Hummingbird A31 board has a VGA DAC which converts RGB output
from the LCD interface to VGA analog signals.

Add nodes for the VGA DAC, its power supply, and enable this part
of the display pipeline.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 arch/arm/boot/dts/sun6i-a31-hummingbird.dts | 67 +++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-a31-hummingbird.dts b/arch/arm/boot/dts/sun6i-a31-hummingbird.dts
index 62287bd2aeb5..b168d6df2b30 100644
--- a/arch/arm/boot/dts/sun6i-a31-hummingbird.dts
+++ b/arch/arm/boot/dts/sun6i-a31-hummingbird.dts
@@ -63,6 +63,60 @@
 		stdout-path = "serial0:115200n8";
 	};
 
+	vga-connector {
+		compatible = "vga-connector";
+
+		port {
+			vga_con_in: endpoint {
+				remote-endpoint = <&vga_dac_out>;
+			};
+		};
+	};
+
+	vga-dac {
+		compatible = "dumb-vga-dac";
+		vdd-supply = <&reg_vga_3v3>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				reg = <0>;
+
+				vga_dac_in: endpoint@0 {
+					reg = <0>;
+					remote-endpoint = <&tcon0_out_vga>;
+				};
+			};
+
+			port@1 {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				reg = <1>;
+
+				vga_dac_out: endpoint@0 {
+					reg = <0>;
+					remote-endpoint = <&vga_con_in>;
+				};
+			};
+		};
+	};
+
+	reg_vga_3v3: vga_3v3_regulator {
+		compatible = "regulator-fixed";
+		regulator-name = "vga-3v3";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-boot-on;
+		enable-active-high;
+		gpio = <&pio 7 25 GPIO_ACTIVE_HIGH>; /* PH25 */
+	};
+
 	wifi_pwrseq: wifi_pwrseq {
 		compatible = "mmc-pwrseq-simple";
 		reset-gpios = <&pio 6 10 GPIO_ACTIVE_LOW>; /* PG10 */
@@ -253,6 +307,19 @@
 	status = "okay";
 };
 
+&tcon0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&lcd0_rgb888_pins>;
+	status = "okay";
+};
+
+&tcon0_out {
+	tcon0_out_vga: endpoint@0 {
+		reg = <0>;
+		remote-endpoint = <&vga_dac_in>;
+	};
+};
+
 &uart0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart0_pins_a>;
-- 
2.10.2

Re: [PATCH v4 2/2] ARM: dts: sun6i: hummingbird-a31: Enable display output through VGA bridge

[Maxime Ripard]

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On Wed, Nov 16, 2016 at 11:42:32PM +0800, Chen-Yu Tsai wrote:
> The Hummingbird A31 board has a VGA DAC which converts RGB output
> from the LCD interface to VGA analog signals.
> 
> Add nodes for the VGA DAC, its power supply, and enable this part
> of the display pipeline.
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>

Applied, thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

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