Hi Abhinav,
Thank you for the patch.
On Thu, Mar 31, 2022 at 05:12:13PM -0700, Abhinav Kumar wrote:
> For some vendor driver implementations, display hardware can
> be shared between the encoder used for writeback and the physical
> display.
>
> In addition resources such as clocks and interrupts can
> also be shared between writeback and the real encoder.
>
> To accommodate such vendor drivers and hardware, allow
> real encoder to be passed for drm_writeback_connector.
>
> changes in v6:
> - assign the encoder inside
> drm_writeback_connector_init_with_encoder() for
> better readability
> - improve some documentation for internal encoder
>
> Co-developed-by: Kandpal Suraj <suraj.kandpal@xxxxxxxxx>
> Signed-off-by: Kandpal Suraj <suraj.kandpal@xxxxxxxxx>
> Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> ---
> drivers/gpu/drm/drm_writeback.c | 18 ++++++++++++------
> drivers/gpu/drm/vc4/vc4_txp.c | 14 ++++++++------
> include/drm/drm_writeback.h | 21 +++++++++++++++++++--
Please split this in two patches, one for the DRM core and one for the
VC4 driver. This applies to most patches as a general rule, with the
main exception being API refactoring that requires changing the
implementation and all its users in a single patch.
> 3 files changed, 39 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
> index 797223c..7f72109 100644
> --- a/drivers/gpu/drm/drm_writeback.c
> +++ b/drivers/gpu/drm/drm_writeback.c
> @@ -179,21 +179,21 @@ int drm_writeback_connector_init(struct drm_device *dev,
> {
> int ret = 0;
>
> - drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
> + drm_encoder_helper_add(&wb_connector->internal_encoder, enc_helper_funcs);
>
> - wb_connector->encoder.possible_crtcs = possible_crtcs;
> + wb_connector->internal_encoder.possible_crtcs = possible_crtcs;
>
> - ret = drm_encoder_init(dev, &wb_connector->encoder,
> + ret = drm_encoder_init(dev, &wb_connector->internal_encoder,
> &drm_writeback_encoder_funcs,
> DRM_MODE_ENCODER_VIRTUAL, NULL);
> if (ret)
> return ret;
>
> - ret = drm_writeback_connector_init_with_encoder(dev, wb_connector, &wb_connector->encoder,
> - con_funcs, formats, n_formats);
> + ret = drm_writeback_connector_init_with_encoder(dev, wb_connector,
> + &wb_connector->internal_encoder, con_funcs, formats, n_formats);
>
> if (ret)
> - drm_encoder_cleanup(&wb_connector->encoder);
> + drm_encoder_cleanup(&wb_connector->internal_encoder);
>
> return ret;
> }
> @@ -238,6 +238,12 @@ int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
> struct drm_mode_config *config = &dev->mode_config;
> int ret = create_writeback_properties(dev);
>
> + /*
> + * Assign the encoder passed to this API to the wb_connector's encoder.
> + * For drm_writeback_connector_init(), this shall be the internal_encoder
> + */
> + wb_connector->encoder = enc;
> +
> if (ret != 0)
> return ret;
>
> diff --git a/drivers/gpu/drm/vc4/vc4_txp.c b/drivers/gpu/drm/vc4/vc4_txp.c
> index 5e53f02..a9b4f83 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.encoder);
> + return container_of(encoder, struct vc4_txp, drm_enc);
> }
>
> static inline struct vc4_txp *connector_to_vc4_txp(struct drm_connector *conn)
> @@ -499,9 +501,9 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
>
> wb_conn = &txp->connector;
>
> - drm_encoder_helper_add(&wb_conn->encoder, &vc4_txp_encoder_helper_funcs);
> + drm_encoder_helper_add(&txp->drm_enc, &vc4_txp_encoder_helper_funcs);
>
> - ret = drm_encoder_init(drm, &wb_conn->encoder,
> + ret = drm_encoder_init(drm, &txp->drm_enc,
> &vc4_txp_encoder_funcs,
> DRM_MODE_ENCODER_VIRTUAL, NULL);
>
> @@ -511,10 +513,10 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
> drm_connector_helper_add(&wb_conn->base,
> &vc4_txp_connector_helper_funcs);
>
> - ret = drm_writeback_connector_init_with_encoder(drm, wb_conn, &wb_conn->encoder,
> + 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(&wb_conn->encoder);
> + drm_encoder_cleanup(&txp->drm_enc);
> return ret;
> }
>
> @@ -523,7 +525,7 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
> if (ret)
> return ret;
>
> - encoder = &txp->connector.encoder;
> + encoder = txp->connector.encoder;
> encoder->possible_crtcs = drm_crtc_mask(crtc);
>
> ret = devm_request_irq(dev, irq, vc4_txp_interrupt, 0,
> diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h
> index 4795024..3f5c330 100644
> --- a/include/drm/drm_writeback.h
> +++ b/include/drm/drm_writeback.h
> @@ -25,15 +25,32 @@ struct drm_writeback_connector {
> struct drm_connector base;
>
> /**
> - * @encoder: Internal encoder used by the connector to fulfill
> + * @encoder: handle to drm_encoder used by the connector to fulfill
> * the DRM framework requirements. The users of the
> * @drm_writeback_connector control the behaviour of the @encoder
> * by passing the @enc_funcs parameter to drm_writeback_connector_init()
> * function.
> + *
> + * For some vendor drivers, the hardware resources are shared between
> + * writeback encoder and rest of the display pipeline.
> + * To accommodate such cases, encoder is a handle to the real encoder
> + * hardware.
> + *
> + * For current existing writeback users, this shall continue to be the
> + * embedded encoder for the writeback connector.
> */
> - struct drm_encoder encoder;
> + struct drm_encoder *encoder;
>
> /**
> + * @internal_encoder: internal encoder used by writeback when
> + * drm_writeback_connector_init() is used.
> + * @encoder will be assigned to this for those cases
> + *
> + * This will be unused when drm_writeback_connector_init_with_encoder()
> + * is used.
> + */
> + struct drm_encoder internal_encoder;
> + /**
> * @pixel_formats_blob_ptr:
> *
> * DRM blob property data for the pixel formats list on writeback
> --
> 2.7.4
>
--
Regards,
Laurent Pinchart
