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@xxxxxxxxxxxxxx> 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@xxxxxxxx>
> > > Acked-by: Rob Herring <robh@xxxxxxxxxx>
> > > ---
> > >  .../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