2022-04-06 17:49:46

by H. Nikolaus Schaller

Subject: [PATCH v17 6/6] drm/bridge: display-connector: add ddc-en gpio support

"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 <[email protected]>
---
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);

--
2.33.0

2022-04-07 21:04:38

by Laurent Pinchart

Subject: Re: [PATCH v17 6/6] drm/bridge: display-connector: add ddc-en gpio support

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 <[email protected]>

Reviewed-by: Laurent Pinchart <[email protected]>

> ---
> 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

2022-04-07 21:14:19

by H. Nikolaus Schaller

Subject: Re: [PATCH v17 6/6] drm/bridge: display-connector: add ddc-en gpio support

Hi Laurent,

> Am 07.04.2022 um 09:30 schrieb Laurent Pinchart <[email protected]>:
>
> 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 <[email protected]>
>
> Reviewed-by: Laurent Pinchart <[email protected]>

Added to v18 (which is needed to remove some now redundant patches
and fix a detail in the ingenic-drm driver).

BR and thanks for review,
Nikolaus