[PATCH 2/2] drm/bridge: tc358762: Add reset GPIO support

[Robert Foss]

On Tue, May 30, 2023 at 9:28 PM Marek Vasut <marex at denx.de> wrote:
>
> Add reset GPIO support. The reset GPIO is cleared after supply regulator
> was enabled, and set before supply regulator is disabled.
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> ---
> Cc: Andrzej Hajda <andrzej.hajda at intel.com>
> Cc: Conor Dooley <conor+dt at kernel.org>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Cc: David Airlie <airlied at gmail.com>
> Cc: Jernej Skrabec <jernej.skrabec at gmail.com>
> Cc: Jonas Karlman <jonas at kwiboo.se>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt at linaro.org>
> Cc: Laurent Pinchart <Laurent.pinchart at ideasonboard.com>
> Cc: Marek Vasut <marex at denx.de>
> Cc: Neil Armstrong <neil.armstrong at linaro.org>
> Cc: Rob Herring <robh+dt at kernel.org>
> Cc: Robert Foss <rfoss at kernel.org>
> Cc: devicetree at vger.kernel.org
> Cc: dri-devel at lists.freedesktop.org
> ---
>  drivers/gpu/drm/bridge/tc358762.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/tc358762.c b/drivers/gpu/drm/bridge/tc358762.c
> index 77f7f7f547570..5641395fd310e 100644
> --- a/drivers/gpu/drm/bridge/tc358762.c
> +++ b/drivers/gpu/drm/bridge/tc358762.c
> @@ -11,6 +11,7 @@
>   */
>
>  #include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/mod_devicetable.h>
>  #include <linux/module.h>
>  #include <linux/of_graph.h>
> @@ -63,6 +64,7 @@ struct tc358762 {
>         struct drm_bridge bridge;
>         struct regulator *regulator;
>         struct drm_bridge *panel_bridge;
> +       struct gpio_desc *reset_gpio;
>         bool pre_enabled;
>         int error;
>  };
> @@ -138,6 +140,9 @@ static void tc358762_post_disable(struct drm_bridge *bridge)
>
>         ctx->pre_enabled = false;
>
> +       if (ctx->reset_gpio)
> +               gpiod_set_value_cansleep(ctx->reset_gpio, 0);
> +
>         ret = regulator_disable(ctx->regulator);
>         if (ret < 0)
>                 dev_err(ctx->dev, "error disabling regulators (%d)\n", ret);
> @@ -152,6 +157,11 @@ static void tc358762_pre_enable(struct drm_bridge *bridge)
>         if (ret < 0)
>                 dev_err(ctx->dev, "error enabling regulators (%d)\n", ret);
>
> +       if (ctx->reset_gpio) {
> +               gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +               usleep_range(5000, 10000);
> +       }
> +
>         ret = tc358762_init(ctx);
>         if (ret < 0)
>                 dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
> @@ -185,6 +195,11 @@ static int tc358762_parse_dt(struct tc358762 *ctx)
>
>         ctx->panel_bridge = panel_bridge;
>
> +       /* Reset GPIO is optional */
> +       ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
> +       if (IS_ERR(ctx->reset_gpio))
> +               return PTR_ERR(ctx->reset_gpio);
> +
>         return 0;
>  }
>
> --
> 2.39.2
>

This all looks good, snoozing it for a few days before applying.

Reviewed-by: Robert Foss <rfoss at kernel.org>