Commit af948a25 authored by Chen-Yu Tsai's avatar Chen-Yu Tsai Committed by Archit Taneja
Browse files

drm/bridge: dumb-vga-dac: Support a VDD regulator supply 



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

Signed-off-by: default avatarChen-Yu Tsai <wens@csie.org>
Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20161116154232.872-2-wens@csie.org
parent 5620f47d

Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt

+2 −0
Original line number Diff line number Diff line
@@ -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

-------

drivers/gpu/drm/bridge/dumb-vga-dac.c

+33 −0
Original line number Diff line number Diff line
@@ -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 +126,30 @@ 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);

}



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 +193,15 @@ 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) {

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