Re: [PATCH v7 4/4] drm/vc4: change vc4 driver to use drm_writeback_connector_init_with_encoder()

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

I am dropping this change because originally I had made this only to 
show usage of drm_writeback_connector_init_with_encoder().

For writeback functionality, vc4 doesnt need this and this seems redundant.

To show the usage of drm_writeback_connector_init_with_encoder(), I have 
posted the MSM writeback driver changes here [1].

[1] https://patchwork.freedesktop.org/series/99724/

Thanks

Abhinav

On 4/8/2022 5:53 PM, Abhinav Kumar wrote:
> vc4 driver currently embeds the drm_encoder into struct vc4_txp
> and later on uses container_of to retrieve the vc4_txp from
> the drm_encoder.
>
> Make vc4 driver use the new API so that the embedded encoder model
> can be retained in the driver and there is no change in
> functionality.
>
> changes in v7:
> 	- remove the drm core changes to previous patch in the series
>
> Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> ---
>   drivers/gpu/drm/vc4/vc4_txp.c | 32 ++++++++++++++++++++++++--------
>   1 file changed, 24 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_txp.c b/drivers/gpu/drm/vc4/vc4_txp.c
> index 7e063a9..0d461df 100644
> --- a/drivers/gpu/drm/vc4/vc4_txp.c
> +++ b/drivers/gpu/drm/vc4/vc4_txp.c
> @@ -151,6 +151,8 @@ struct vc4_txp {
>   
>   	struct platform_device *pdev;
>   
> +	struct drm_encoder drm_enc;
> +
>   	struct drm_writeback_connector connector;
>   
>   	void __iomem *regs;
> @@ -159,7 +161,7 @@ struct vc4_txp {
>   
>   static inline struct vc4_txp *encoder_to_vc4_txp(struct drm_encoder *encoder)
>   {
> -	return container_of(encoder, struct vc4_txp, connector.internal_encoder);
> +	return container_of(encoder, struct vc4_txp, drm_enc);
>   }
>   
>   static inline struct vc4_txp *connector_to_vc4_txp(struct drm_connector *conn)
> @@ -368,6 +370,10 @@ static const struct drm_encoder_helper_funcs vc4_txp_encoder_helper_funcs = {
>   	.disable = vc4_txp_encoder_disable,
>   };
>   
> +static const struct drm_encoder_funcs vc4_txp_encoder_funcs = {
> +	.destroy = drm_encoder_cleanup,
> +};
> +
>   static int vc4_txp_enable_vblank(struct drm_crtc *crtc)
>   {
>   	return 0;
> @@ -467,6 +473,7 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
>   	struct vc4_txp *txp;
>   	struct drm_crtc *crtc;
>   	struct drm_encoder *encoder;
> +	struct drm_writeback_connector *wb_conn;
>   	int ret, irq;
>   
>   	irq = platform_get_irq(pdev, 0);
> @@ -492,16 +499,25 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
>   	txp->regset.regs = txp_regs;
>   	txp->regset.nregs = ARRAY_SIZE(txp_regs);
>   
> -	drm_connector_helper_add(&txp->connector.base,
> -				 &vc4_txp_connector_helper_funcs);
> -	ret = drm_writeback_connector_init(drm, &txp->connector,
> -					   &vc4_txp_connector_funcs,
> -					   &vc4_txp_encoder_helper_funcs,
> -					   drm_fmts, ARRAY_SIZE(drm_fmts),
> -					   0);
> +	wb_conn = &txp->connector;
> +
> +	drm_encoder_helper_add(&txp->drm_enc, &vc4_txp_encoder_helper_funcs);
> +
> +	ret = drm_encoder_init(drm, &txp->drm_enc, &vc4_txp_encoder_funcs,
> +			DRM_MODE_ENCODER_VIRTUAL, NULL);
>   	if (ret)
>   		return ret;
>   
> +	drm_connector_helper_add(&wb_conn->base, &vc4_txp_connector_helper_funcs);
> +
> +	ret = drm_writeback_connector_init_with_encoder(drm, wb_conn, &txp->drm_enc,
> +			&vc4_txp_connector_funcs, drm_fmts, ARRAY_SIZE(drm_fmts));
> +
> +	if (ret) {
> +		drm_encoder_cleanup(&txp->drm_enc);
> +		return ret;
> +	}
> +
>   	ret = vc4_crtc_init(drm, vc4_crtc,
>   			    &vc4_txp_crtc_funcs, &vc4_txp_crtc_helper_funcs);
>   	if (ret)