[PATCH v2 4/7] drm: rcar-du: lvds: Fix stop sequence

[Laurent Pinchart]

Hi Tomi,

Thank you for the patch.

On Fri, Jan 20, 2023 at 10:50:06AM +0200, Tomi Valkeinen wrote:
> From: Koji Matsuoka <koji.matsuoka.xm at renesas.com>
> 
> According to hardware manual, LVDCR0 register must be cleared bit by bit
> when disabling LVDS.
> 
> Signed-off-by: Koji Matsuoka <koji.matsuoka.xm at renesas.com>
> Signed-off-by: LUU HOAI <hoai.luu.ub at renesas.com>
> [tomi.valkeinen: simplified the code a bit]
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas at ideasonboard.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> ---
>  drivers/gpu/drm/rcar-du/rcar_lvds.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
> index 668604616bfd..8fa5f7400179 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
> @@ -83,6 +83,11 @@ struct rcar_lvds {
>  #define bridge_to_rcar_lvds(b) \
>  	container_of(b, struct rcar_lvds, bridge)
>  
> +static u32 rcar_lvds_read(struct rcar_lvds *lvds, u32 reg)
> +{
> +	return ioread32(lvds->mmio + reg);
> +}
> +
>  static void rcar_lvds_write(struct rcar_lvds *lvds, u32 reg, u32 data)
>  {
>  	iowrite32(data, lvds->mmio + reg);
> @@ -544,6 +549,27 @@ static void rcar_lvds_atomic_disable(struct drm_bridge *bridge,
>  				     struct drm_bridge_state *old_bridge_state)
>  {
>  	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
> +	u32 lvdcr0;
> +
> +	lvdcr0 = rcar_lvds_read(lvds, LVDCR0);
> +
> +	lvdcr0 &= ~LVDCR0_LVRES;
> +	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
> +
> +	if (lvds->info->quirks & RCAR_LVDS_QUIRK_GEN3_LVEN) {
> +		lvdcr0 &= ~LVDCR0_LVEN;
> +		rcar_lvds_write(lvds, LVDCR0, lvdcr0);
> +	}
> +
> +	if (lvds->info->quirks & RCAR_LVDS_QUIRK_PWD) {
> +		lvdcr0 &= ~LVDCR0_PWD;
> +		rcar_lvds_write(lvds, LVDCR0, lvdcr0);
> +	}
> +
> +	if (!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)) {
> +		lvdcr0 &= ~LVDCR0_PLLON;
> +		rcar_lvds_write(lvds, LVDCR0, lvdcr0);
> +	}
>  
>  	rcar_lvds_write(lvds, LVDCR0, 0);
>  	rcar_lvds_write(lvds, LVDCR1, 0);

-- 
Regards,

Laurent Pinchart