Hi Nikolaus,
Thank you for the patch.
On Wed, Apr 06, 2022 at 06:26:08PM +0200, H. Nikolaus Schaller wrote:
> "hdmi-connector.yaml" bindings defines an optional property
> "ddc-en-gpios" for a single gpio to enable DDC operation.
>
> Usually this controls +5V power on the HDMI connector.
> This +5V may also be needed for HPD.
>
> This was not reflected in code but is needed to make the CI20
> board work.
>
> Now, the driver activates the ddc gpio after probe and
> deactivates after remove so it is "almost on".
>
> But only if this driver is loaded (and not e.g. blacklisted
> as module).
>
> Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/display-connector.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/display-connector.c b/drivers/gpu/drm/bridge/display-connector.c
> index d24f5b90feabf..e4d52a7e31b71 100644
> --- a/drivers/gpu/drm/bridge/display-connector.c
> +++ b/drivers/gpu/drm/bridge/display-connector.c
> @@ -24,6 +24,7 @@ struct display_connector {
> int hpd_irq;
>
> struct regulator *dp_pwr;
> + struct gpio_desc *ddc_en;
> };
>
> static inline struct display_connector *
> @@ -345,6 +346,17 @@ static int display_connector_probe(struct platform_device *pdev)
> }
> }
>
> + /* enable DDC */
> + if (type == DRM_MODE_CONNECTOR_HDMIA) {
> + conn->ddc_en = devm_gpiod_get_optional(&pdev->dev, "ddc-en",
> + GPIOD_OUT_HIGH);
> +
> + if (IS_ERR(conn->ddc_en)) {
> + dev_err(&pdev->dev, "Couldn't get ddc-en gpio\n");
> + return PTR_ERR(conn->ddc_en);
> + }
> + }
> +
> conn->bridge.funcs = &display_connector_bridge_funcs;
> conn->bridge.of_node = pdev->dev.of_node;
>
> @@ -373,6 +385,9 @@ static int display_connector_remove(struct platform_device *pdev)
> {
> struct display_connector *conn = platform_get_drvdata(pdev);
>
> + if (conn->ddc_en)
> + gpiod_set_value(conn->ddc_en, 0);
> +
> if (conn->dp_pwr)
> regulator_disable(conn->dp_pwr);
>
--
Regards,
Laurent Pinchart
