Re: [PATCH v2 4/4] drm/bridge: ti-sn65dsi83: Add vcc supply regulator support

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Alexander,

Thank you for the patch.

On Tue, Oct 12, 2021 at 08:48:43AM +0200, Alexander Stein wrote:
> VCC needs to be enabled before releasing the enable GPIO.
> 
> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> ---
>  drivers/gpu/drm/bridge/ti-sn65dsi83.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> index 9072342566f3..a6b1fd71dfee 100644
> --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> @@ -33,6 +33,7 @@
>  #include <linux/of_device.h>
>  #include <linux/of_graph.h>
>  #include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
>  
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_bridge.h>
> @@ -143,6 +144,7 @@ struct sn65dsi83 {
>  	struct mipi_dsi_device		*dsi;
>  	struct drm_bridge		*panel_bridge;
>  	struct gpio_desc		*enable_gpio;
> +	struct regulator		*vcc;
>  	int				dsi_lanes;
>  	bool				lvds_dual_link;
>  	bool				lvds_dual_link_even_odd_swap;
> @@ -647,6 +649,12 @@ static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model)
>  
>  	ctx->panel_bridge = panel_bridge;
>  
> +	ctx->vcc = devm_regulator_get(dev, "vcc");
> +	if (IS_ERR(ctx->vcc))
> +		return dev_err_probe(dev, PTR_ERR(ctx->vcc),
> +				     "Failed to get supply 'vcc': %pe\n",
> +				     ctx->vcc);
> +
>  	return 0;
>  }
>  
> @@ -691,7 +699,11 @@ static int sn65dsi83_probe(struct i2c_client *client,
>  	ctx->bridge.of_node = dev->of_node;
>  	drm_bridge_add(&ctx->bridge);
>  
> -	return 0;
> +	ret = regulator_enable(ctx->vcc);
> +	if (ret)
> +		dev_err(dev, "Failed to enable vcc: %i\n", ret);

I think this should move to sn65dsi83_atomic_pre_enable() (and similarly
for regulator_disable()) as keeping the regulator enabled at all times
will cost power.

> +
> +	return ret;
>  }
>  
>  static int sn65dsi83_remove(struct i2c_client *client)
> @@ -702,6 +714,7 @@ static int sn65dsi83_remove(struct i2c_client *client)
>  	mipi_dsi_device_unregister(ctx->dsi);
>  	drm_bridge_remove(&ctx->bridge);
>  	of_node_put(ctx->host_node);
> +	regulator_disable(ctx->vcc);
>  
>  	return 0;
>  }

-- 
Regards,

Laurent Pinchart