Hi Alexander,
Thank you for the patch.
On Thu, Nov 18, 2021 at 10:19:55AM +0100, Alexander Stein wrote:
> VCC needs to be enabled before releasing the enable GPIO.
>
> Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/ti-sn65dsi83.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> index 065610edc37a..54d18e82ed74 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;
> @@ -337,6 +339,12 @@ static void sn65dsi83_atomic_enable(struct drm_bridge *bridge,
> u16 val;
> int ret;
>
> + ret = regulator_enable(ctx->vcc);
> + if (ret) {
> + dev_err(ctx->dev, "Failed to enable vcc\n");
I'd print the error code here as you do so in
sn65dsi83_atomic_disable().
> + return;
> + }
> +
> /* Deassert reset */
> gpiod_set_value(ctx->enable_gpio, 1);
> usleep_range(1000, 1100);
> @@ -486,11 +494,16 @@ static void sn65dsi83_atomic_disable(struct drm_bridge *bridge,
> struct drm_bridge_state *old_bridge_state)
> {
> struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
> + int ret;
>
> /* Put the chip in reset, pull EN line low, and assure 10ms reset low timing. */
> gpiod_set_value(ctx->enable_gpio, 0);
> usleep_range(10000, 11000);
>
> + ret = regulator_disable(ctx->vcc);
> + if (ret)
> + dev_err(ctx->dev, "Failed to disable vcc: %i\n", ret);
I wish printf didn't have identical %i and %d specifiers :-)
> +
> regcache_mark_dirty(ctx->regmap);
> }
>
> @@ -599,6 +612,12 @@ 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",
> + ERR_PTR(ret));
This doesn't seem right, ret doesn't contain any useful error code at
this point.
return dev_err_probe(dev, PTR_ERR(ctx->vcc),
"Failed to get supply 'vcc'\n");
should be enough, as dev_err_probe() adds the error to the message
internally.
With those small fixes,
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> +
> return 0;
> }
>
--
Regards,
Laurent Pinchart
