[PATCH 3/3] drm/bridge: tc358767: disable main link PHYs on main link disable

[Robert Foss]

On Wed, 6 Jul 2022 at 15:28, Lucas Stach <l.stach at pengutronix.de> wrote:
>
> Disable the main link PHYs and put them into reset when the main link
> is disabled. When the PHYs stay enabled while the rest of the DP link
> circuits are disabled there is some noise on the data lanes, which some
> displays try to lock onto, waking them up from their low power state.
>
> Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> ---
>  drivers/gpu/drm/bridge/tc358767.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
> index fd4936215b55..615b4988bf34 100644
> --- a/drivers/gpu/drm/bridge/tc358767.c
> +++ b/drivers/gpu/drm/bridge/tc358767.c
> @@ -1249,7 +1249,13 @@ static int tc_main_link_disable(struct tc_data *tc)
>         if (ret)
>                 return ret;
>
> -       return regmap_write(tc->regmap, DP0CTL, 0);
> +       ret = regmap_write(tc->regmap, DP0CTL, 0);
> +       if (ret)
> +               return ret;
> +
> +       return regmap_update_bits(tc->regmap, DP_PHY_CTRL,
> +                                 PHY_M0_RST | PHY_M1_RST | PHY_M0_EN,
> +                                 PHY_M0_RST | PHY_M1_RST);
>  }
>
>  static int tc_dsi_rx_enable(struct tc_data *tc)
> --
> 2.30.2
>

Reviewed-by: Robert Foss <robert.foss at linaro.org>