Re: [PATCH v2 2/2] drm/sun4i: Add alpha property for sun8i and sun50i VI layer

[Jernej Åkrabec]

Hi!

Dne ponedeljek, 30. december 2019 ob 19:08:42 CET je 
roman.stratiienko@xxxxxxxxxxxxxxx napisal(a):
> From: Roman Stratiienko <roman.stratiienko@xxxxxxxxxxxxxxx>
> 
> DE3.0 VI layers supports plane-global alpha channel.
> DE2.0 FCC block have GLOBAL_ALPHA register that can be used as alpha source
> for blender.
> 
> Add alpha property to the DRM plane and connect it to the
> corresponding registers in the mixer.
> 
> Signed-off-by: Roman Stratiienko <roman.stratiienko@xxxxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/sun4i/sun8i_vi_layer.c | 46 +++++++++++++++++++++-----
>  drivers/gpu/drm/sun4i/sun8i_vi_layer.h | 11 ++++++
>  2 files changed, 49 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/sun4i/sun8i_vi_layer.c
> b/drivers/gpu/drm/sun4i/sun8i_vi_layer.c index 42d445d23773..db32a78c75d9
> 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_vi_layer.c
> +++ b/drivers/gpu/drm/sun4i/sun8i_vi_layer.c
> @@ -65,6 +65,36 @@ static void sun8i_vi_layer_enable(struct sun8i_mixer
> *mixer, int channel, }
>  }
> 
> +static void sun8i_vi_layer_update_alpha(struct sun8i_mixer *mixer, int
> channel, +					int overlay, struct 
drm_plane *plane)
> +{
> +	u32 mask, val, ch_base;
> +
> +	ch_base = sun8i_channel_base(mixer, channel);
> +
> +	if (mixer->cfg->is_de3) {
> +		mask = SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA_MASK |
> +		       SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA_MODE_MASK;
> +		val = SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA
> +			(plane->state->alpha >> 8);
> +
> +		val |= (plane->state->alpha == DRM_BLEND_ALPHA_OPAQUE) ?
> +			
SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA_MODE_PIXEL :
> +			
SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA_MODE_COMBINED;
> +
> +		regmap_update_bits(mixer->engine.regs,
> +				   
SUN8I_MIXER_CHAN_VI_LAYER_ATTR(ch_base,
> +								
  overlay),
> +				   mask, val);
> +	} else {
> +		regmap_update_bits(mixer->engine.regs,
> +				   
SUN8I_MIXER_FCC_GLOBAL_ALPHA_REG,
> +				   
SUN8I_MIXER_FCC_GLOBAL_ALPHA_MASK,
> +				   SUN8I_MIXER_FCC_GLOBAL_ALPHA
> +					(plane->state->alpha >> 
8));

In general, this is fine, except I don't know how this will work on V3. V3 is 
the only SoC which have 2 VI layers in one mixer. I checked DE2 BSP sources 
and only only one VI alpha is defined in FCC, also for V3. BSP driver also 
doesn't use this field at all, so I don't know if they missed it or it's really 
only one alpha for both VI layers. I don't have V3 board, so I can't do any 
experiment. To be on the safe side, we could check if mixer has > 1 VI plane 
and if it is DE2 and skip adding alpha property for such combination for now.

What do you think?

Best regards,
Jernej

> +	}
> +}
> +
>  static int sun8i_vi_layer_update_coord(struct sun8i_mixer *mixer, int
> channel, int overlay, struct drm_plane *plane,
>  				       unsigned int zpos)
> @@ -248,14 +278,6 @@ static int sun8i_vi_layer_update_formats(struct
> sun8i_mixer *mixer, int channel, SUN8I_MIXER_CHAN_VI_LAYER_ATTR(ch_base,
> overlay),
>  			   SUN8I_MIXER_CHAN_VI_LAYER_ATTR_RGB_MODE, 
val);
> 
> -	/* It seems that YUV formats use global alpha setting. */
> -	if (mixer->cfg->is_de3)
> -		regmap_update_bits(mixer->engine.regs,
> -				   
SUN8I_MIXER_CHAN_VI_LAYER_ATTR(ch_base,
> -								
  overlay),
> -				   
SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA_MASK,
> -				   
SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA(0xff));
> -
>  	return 0;
>  }
> 
> @@ -373,6 +395,8 @@ static void sun8i_vi_layer_atomic_update(struct
> drm_plane *plane,
> 
>  	sun8i_vi_layer_update_coord(mixer, layer->channel,
>  				    layer->overlay, plane, zpos);
> +	sun8i_vi_layer_update_alpha(mixer, layer->channel,
> +				    layer->overlay, plane);
>  	sun8i_vi_layer_update_formats(mixer, layer->channel,
>  				      layer->overlay, plane);
>  	sun8i_vi_layer_update_buffer(mixer, layer->channel,
> @@ -464,6 +488,12 @@ struct sun8i_vi_layer *sun8i_vi_layer_init_one(struct
> drm_device *drm,
> 
>  	plane_cnt = mixer->cfg->ui_num + mixer->cfg->vi_num;
> 
> +	ret = drm_plane_create_alpha_property(&layer->plane);
> +	if (ret) {
> +		dev_err(drm->dev, "Couldn't add alpha property\n");
> +		return ERR_PTR(ret);
> +	}
> +
>  	ret = drm_plane_create_zpos_property(&layer->plane, index,
>  					     0, plane_cnt - 
1);
>  	if (ret) {
> diff --git a/drivers/gpu/drm/sun4i/sun8i_vi_layer.h
> b/drivers/gpu/drm/sun4i/sun8i_vi_layer.h index eaa6076f5dbc..48c399e1c86d
> 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_vi_layer.h
> +++ b/drivers/gpu/drm/sun4i/sun8i_vi_layer.h
> @@ -29,14 +29,25 @@
>  #define SUN8I_MIXER_CHAN_VI_VDS_UV(base) \
>  		((base) + 0xfc)
> 
> +#define SUN8I_MIXER_FCC_GLOBAL_ALPHA_REG \
> +		(0xAA000 + 0x90)
> +
> +#define SUN8I_MIXER_FCC_GLOBAL_ALPHA(x)			((x) << 24)
> +#define SUN8I_MIXER_FCC_GLOBAL_ALPHA_MASK		GENMASK(31, 
24)
> +
>  #define SUN8I_MIXER_CHAN_VI_LAYER_ATTR_EN		BIT(0)
>  /* RGB mode should be set for RGB formats and cleared for YCbCr */
>  #define SUN8I_MIXER_CHAN_VI_LAYER_ATTR_RGB_MODE		BIT(15)
>  #define SUN8I_MIXER_CHAN_VI_LAYER_ATTR_FBFMT_OFFSET	8
>  #define SUN8I_MIXER_CHAN_VI_LAYER_ATTR_FBFMT_MASK	GENMASK(12, 8)
> +#define SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA_MODE_MASK	GENMASK(2, 1)
>  #define SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA_MASK	GENMASK(31, 24)
>  #define SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA(x)	((x) << 24)
> 
> +#define SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA_MODE_PIXEL	((0) << 1)
> +#define SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA_MODE_LAYER	((1) << 1)
> +#define SUN50I_MIXER_CHAN_VI_LAYER_ATTR_ALPHA_MODE_COMBINED	((2) << 1)
> +
>  #define SUN8I_MIXER_CHAN_VI_DS_N(x)			((x) << 16)
>  #define SUN8I_MIXER_CHAN_VI_DS_M(x)			((x) << 0)