On Sat, Oct 29, 2016 at 07:06:10PM +0800, 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 at csie.org>
> ---
> .../bindings/display/bridge/dumb-vga-dac.txt | 2 ++
For the binding,
Acked-by: Rob Herring <robh at kernel.org>
One code comment below...
> 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..59781e031220 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 +126,33 @@ 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;
> +
> + if (!IS_ERR(vga->vdd)) {
if (IS_ERR())
return;
...will save some intentation.
> + 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 (!IS_ERR(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 +196,14 @@ 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;
> + 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) {
> --
> 2.9.3
>
