[PATCH] drm/mediatek: Support reflect-y plane rotation

[CK Hu]

Hi, Sean:

On Fri, 2019-11-01 at 09:26 -0400, Sean Paul wrote:
> From: Sean Paul <seanpaul at chromium.org>
> 
> Expose the rotation property and handle REFLECT_Y rotations.
> 
> Cc: Fritz Koenig <frkoenig at chromium.org>
> Cc: Daniele Castagna <dcastagna at chromium.org>
> Cc: Miguel Casas <mcasas at chromium.org>
> Cc: Mark Yacoub <markyacoub at google.com>
> Signed-off-by: Sean Paul <seanpaul at chromium.org>
> ---
> 
> The hardware also supports REFLECT_X, but I just could not figure out
> how to get it working. If someone is interested in getting this going,
> I'm happy to share notes and my WIP patch. For now, though, I actually
> only need y-flip so I'm giving up on x-flip.
> 
> 
>  drivers/gpu/drm/mediatek/mtk_disp_ovl.c  |  6 ++++++
>  drivers/gpu/drm/mediatek/mtk_drm_plane.c | 11 ++++++++++-
>  drivers/gpu/drm/mediatek/mtk_drm_plane.h |  1 +
>  3 files changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> index 14878ebf59d7..6505479ee506 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> @@ -50,6 +50,7 @@
>  					OVL_CON_CLRFMT_RGB : 0)
>  #define	OVL_CON_AEN		BIT(8)
>  #define	OVL_CON_ALPHA		0xff
> +#define	OVL_CON_VIRT_FLIP	BIT(9)
>  
>  struct mtk_disp_ovl_data {
>  	unsigned int addr;
> @@ -229,6 +230,11 @@ static void mtk_ovl_layer_config(struct mtk_ddp_comp *comp, unsigned int idx,
>  	if (idx != 0)
>  		con |= OVL_CON_AEN | OVL_CON_ALPHA;
>  
> +	if (pending->rotation & DRM_MODE_REFLECT_Y) {
> +		con |= OVL_CON_VIRT_FLIP;
> +		addr += (pending->height - 1) * pending->pitch;
> +	}
> +
>  	writel_relaxed(con, comp->regs + DISP_REG_OVL_CON(idx));
>  	writel_relaxed(pitch, comp->regs + DISP_REG_OVL_PITCH(idx));
>  	writel_relaxed(src_size, comp->regs + DISP_REG_OVL_SRC_SIZE(idx));
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> index 584a9ecadce6..4d8f2b55334b 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> @@ -88,6 +88,9 @@ static int mtk_plane_atomic_check(struct drm_plane *plane,
>  	if (!fb)
>  		return 0;
>  
> +	if (fb->format->is_yuv && (state->rotation & ~DRM_MODE_ROTATE_0) != 0)
> +		return -EINVAL;
> +

For some crtc, its DMA component (first component in crtc pipe line
which read data from DRAM) may be RDMA [1]. It does not support RDMA
reflect function in this patch, so need to do something to protect this
case. Maybe we should check this plane is bind to a crtc whose DMA
component support reflect or not.

[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/mediatek/mtk_drm_drv.c?h=v5.4-rc6#n133

Regards,
CK

>  	if (!state->crtc)
>  		return 0;
>  
> @@ -132,6 +135,7 @@ static void mtk_plane_atomic_update(struct drm_plane *plane,
>  	state->pending.y = plane->state->dst.y1;
>  	state->pending.width = drm_rect_width(&plane->state->dst);
>  	state->pending.height = drm_rect_height(&plane->state->dst);
> +	state->pending.rotation = plane->state->rotation;
>  	wmb(); /* Make sure the above parameters are set before update */
>  	state->pending.dirty = true;
>  }
> @@ -166,7 +170,12 @@ int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane,
>  		return err;
>  	}
>  
> -	drm_plane_helper_add(plane, &mtk_plane_helper_funcs);
> +	err = drm_plane_create_rotation_property(plane, 0,
> +						 DRM_MODE_ROTATE_0 |
> +						 DRM_MODE_REFLECT_Y);
> +	if (err)
> +		DRM_INFO("Create rotation property failed, continuing...\n");
>  
> +	drm_plane_helper_add(plane, &mtk_plane_helper_funcs);
>  	return 0;
>  }
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.h b/drivers/gpu/drm/mediatek/mtk_drm_plane.h
> index 6f842df722c7..83b634a997cc 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.h
> @@ -20,6 +20,7 @@ struct mtk_plane_pending_state {
>  	unsigned int			y;
>  	unsigned int			width;
>  	unsigned int			height;
> +	unsigned int			rotation;
>  	bool				dirty;
>  };
>