On 11/17/2016 01:25 PM, Chen-Yu Tsai wrote:

On Thu, Nov 17, 2016 at 3:48 PM, Archit Taneja [off-list ref] wrote:

quoted

Hi,

Thanks for the patch.


On 11/16/2016 09:12 PM, Chen-Yu Tsai wrote:

quoted

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 <redacted>
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

quoted

Thanks,
Archit

quoted

+       }
+}
+
+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) {

--
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a Linux Foundation Collaborative Project

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