diff mbox series

[v6,11/28] drm/dsc: Add helpers for DSC picture parameter set infoframes

Message ID 20181024222840.25683-12-manasi.d.navare@intel.com (mailing list archive)
State New, archived
Headers show
Series Display Stream Compression enabling on eDP/DP | expand

Commit Message

Navare, Manasi Oct. 24, 2018, 10:28 p.m. UTC
According to Display Stream compression spec 1.2, the picture
parameter set metadata is sent from source to sink device
using the DP Secondary data packet. An infoframe is formed
for the PPS SDP header and PPS SDP payload bytes.
This patch adds helpers to fill the PPS SDP header
and PPS SDP payload according to the DSC 1.2 specification.

v6:
* Use proper sequence points for breaking down the
assignments (Chris Wilson)
* Use SPDX identifier
v5:
Do not use bitfields for DRM structs (Jani N)
v4:
* Use DSC constants for params that dont change across
configurations
v3:
* Add reference to added kernel-docs in Documentation/gpu/drm-kms-helpers.rst
(Daniel Vetter)

v2:
* Add EXPORT_SYMBOL for the drm functions (Manasi)

Cc: dri-devel@lists.freedesktop.org
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
---
 Documentation/gpu/drm-kms-helpers.rst |  12 ++
 drivers/gpu/drm/Makefile              |   2 +-
 drivers/gpu/drm/drm_dsc.c             | 223 ++++++++++++++++++++++++++
 include/drm/drm_dsc.h                 |  22 +++
 4 files changed, 258 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/drm_dsc.c

Comments

Ville Syrjala Nov. 1, 2018, 4:46 p.m. UTC | #1
On Wed, Oct 24, 2018 at 03:28:23PM -0700, Manasi Navare wrote:
> According to Display Stream compression spec 1.2, the picture
> parameter set metadata is sent from source to sink device
> using the DP Secondary data packet. An infoframe is formed
> for the PPS SDP header and PPS SDP payload bytes.
> This patch adds helpers to fill the PPS SDP header
> and PPS SDP payload according to the DSC 1.2 specification.
> 
> v6:
> * Use proper sequence points for breaking down the
> assignments (Chris Wilson)
> * Use SPDX identifier
> v5:
> Do not use bitfields for DRM structs (Jani N)
> v4:
> * Use DSC constants for params that dont change across
> configurations
> v3:
> * Add reference to added kernel-docs in Documentation/gpu/drm-kms-helpers.rst
> (Daniel Vetter)
> 
> v2:
> * Add EXPORT_SYMBOL for the drm functions (Manasi)
> 
> Cc: dri-devel@lists.freedesktop.org
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
> Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
> Cc: Harry Wentland <harry.wentland@amd.com>
> Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> Acked-by: Harry Wentland <harry.wentland@amd.com>
> ---
>  Documentation/gpu/drm-kms-helpers.rst |  12 ++
>  drivers/gpu/drm/Makefile              |   2 +-
>  drivers/gpu/drm/drm_dsc.c             | 223 ++++++++++++++++++++++++++
>  include/drm/drm_dsc.h                 |  22 +++
>  4 files changed, 258 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/drm_dsc.c
> 
> diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
> index 4b4dc236ef6f..b422eb8edf16 100644
> --- a/Documentation/gpu/drm-kms-helpers.rst
> +++ b/Documentation/gpu/drm-kms-helpers.rst
> @@ -232,6 +232,18 @@ MIPI DSI Helper Functions Reference
>  .. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
>     :export:
>  
> +Display Stream Compression Helper Functions Reference
> +=====================================================
> +
> +.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
> +   :doc: dsc helpers
> +
> +.. kernel-doc:: include/drm/drm_dsc.h
> +   :internal:
> +
> +.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
> +   :export:
> +
>  Output Probing Helper Functions Reference
>  =========================================
>  
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 576ba985e138..3a3e6fb6d476 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -32,7 +32,7 @@ drm-$(CONFIG_AGP) += drm_agpsupport.o
>  drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
>  drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
>  
> -drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \
> +drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper.o \
>  		drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \
>  		drm_kms_helper_common.o drm_dp_dual_mode_helper.o \
>  		drm_simple_kms_helper.o drm_modeset_helper.o \
> diff --git a/drivers/gpu/drm/drm_dsc.c b/drivers/gpu/drm/drm_dsc.c
> new file mode 100644
> index 000000000000..21ae8d015afd
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_dsc.c
> @@ -0,0 +1,223 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2018 Intel Corp
> + *
> + * Author:
> + * Manasi Navare <manasi.d.navare@intel.com>
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/errno.h>
> +#include <drm/drm_dp_helper.h>
> +#include <drm/drm_dsc.h>
> +
> +/**
> + * DOC: dsc helpers
> + *
> + * These functions contain some common logic and helpers to deal with VESA
> + * Display Stream Compression standard required for DSC on Display Port/eDP or
> + * MIPI display interfaces.
> + */
> +
> +/**
> + * drm_dsc_dp_pps_header_init() - Initializes the PPS Header
> + * for DisplayPort as per the DP 1.4 spec.
> + * @pps_sdp: Secondary data packet for DSC Picture Parameter Set
> + */
> +void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp)
> +{
> +	memset(&pps_sdp->pps_header, 0, sizeof(pps_sdp->pps_header));
> +
> +	pps_sdp->pps_header.HB1 = DP_SDP_PPS;
> +	pps_sdp->pps_header.HB2 = DP_SDP_PPS_HEADER_PAYLOAD_BYTES_MINUS_1;
> +}
> +EXPORT_SYMBOL(drm_dsc_dp_pps_header_init);
> +
> +/**
> + * drm_dsc_pps_infoframe_pack() - Populates the DSC PPS infoframe
> + * using the DSC configuration parameters in the order expected
> + * by the DSC Display Sink device. For the DSC, the sink device
> + * expects the PPS payload in the big endian format for the fields
> + * that span more than 1 byte.
> + *
> + * @pps_sdp:
> + * Secondary data packet for DSC Picture Parameter Set
> + * @dsc_cfg:
> + * DSC Configuration data filled by driver
> + */
> +void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
> +				struct drm_dsc_config *dsc_cfg)
> +{
> +	u8 i = 0;

int i;

> +
> +	memset(&pps_sdp->pps_payload, 0, sizeof(pps_sdp->pps_payload));
> +
> +	/* PPS 0 */
> +	pps_sdp->pps_payload.dsc_version =
> +		dsc_cfg->dsc_version_minor |
> +		dsc_cfg->dsc_version_major << DSC_PPS_VERSION_MAJOR_SHIFT;
> +
> +	/* PPS 1, 2 is 0 */
> +
> +	/* PPS 3 */
> +	pps_sdp->pps_payload.pps_3 =
> +		dsc_cfg->line_buf_depth |
> +		dsc_cfg->bits_per_component << DSC_PPS_BPC_SHIFT;
> +
> +	/* PPS 4 */
> +	pps_sdp->pps_payload.pps_4 =
> +		(u8)((dsc_cfg->bits_per_pixel & DSC_PPS_BPP_HIGH_MASK) >>
> +		     DSC_PPS_MSB_SHIFT) |
> +		(u8)dsc_cfg->vbr_enable << DSC_PPS_VBR_EN_SHIFT |
> +		(u8)dsc_cfg->enable422 << DSC_PPS_SIMPLE422_SHIFT |
> +		(u8)dsc_cfg->convert_rgb << DSC_PPS_CONVERT_RGB_SHIFT |
> +		(u8)dsc_cfg->block_pred_enable << DSC_PPS_BLOCK_PRED_EN_SHIFT;

What's with all the (u8) casts?

> +
> +	/* PPS 5 */
> +	pps_sdp->pps_payload.bits_per_pixel_low =
> +		(u8)(dsc_cfg->bits_per_pixel & DSC_PPS_LSB_MASK);
> +
> +	/*
> +	 * The DSC panel expects the PPS packet to have big endian format
> +	 * for data spanning 2 bytes. Use a macro cpu_to_be16() to convert
> +	 * to big endian format. If format is little endian, it will swap
> +	 * bytes to convert to Big endian else keep it unchanged.
> +	 */
> +
> +	/* PPS 6, 7 */
> +	pps_sdp->pps_payload.pic_height = cpu_to_be16(dsc_cfg->pic_height);
> +
> +	/* PPS 8, 9 */
> +	pps_sdp->pps_payload.pic_width = cpu_to_be16(dsc_cfg->pic_width);
> +
> +	/* PPS 10, 11 */
> +	pps_sdp->pps_payload.slice_height = cpu_to_be16(dsc_cfg->slice_height);
> +
> +	/* PPS 12, 13 */
> +	pps_sdp->pps_payload.slice_width = cpu_to_be16(dsc_cfg->slice_width);
> +
> +	/* PPS 14, 15 */
> +	pps_sdp->pps_payload.chunk_size = cpu_to_be16(dsc_cfg->slice_chunk_size);
> +
> +	/* PPS 16 */
> +	pps_sdp->pps_payload.initial_xmit_delay_high =
> +		(u8)((dsc_cfg->initial_xmit_delay &
> +		      DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK) >>
> +		     DSC_PPS_MSB_SHIFT);
> +
> +	/* PPS 17 */
> +	pps_sdp->pps_payload.initial_xmit_delay_low =
> +		(u8)(dsc_cfg->initial_xmit_delay & DSC_PPS_LSB_MASK);
> +
> +	/* PPS 18, 19 */
> +	pps_sdp->pps_payload.initial_dec_delay =
> +		cpu_to_be16(dsc_cfg->initial_dec_delay);
> +
> +	/* PPS 20 is 0 */
> +
> +	/* PPS 21 */
> +	pps_sdp->pps_payload.initial_scale_value =
> +		(u8)dsc_cfg->initial_scale_value;
> +
> +	/* PPS 22, 23 */
> +	pps_sdp->pps_payload.scale_increment_interval =
> +		cpu_to_be16(dsc_cfg->scale_increment_interval);
> +
> +	/* PPS 24 */
> +	pps_sdp->pps_payload.scale_decrement_interval_high =
> +		(u8)((dsc_cfg->scale_decrement_interval &
> +		      DSC_PPS_SCALE_DEC_INT_HIGH_MASK) >>
> +		     DSC_PPS_MSB_SHIFT);
> +
> +	/* PPS 25 */
> +	pps_sdp->pps_payload.scale_decrement_interval_low =
> +		(u8)(dsc_cfg->scale_decrement_interval & DSC_PPS_LSB_MASK);
> +
> +	/* PPS 26[7:0], PPS 27[7:5] RESERVED */
> +
> +	/* PPS 27 */
> +	pps_sdp->pps_payload.first_line_bpg_offset =
> +		(u8)dsc_cfg->first_line_bpg_offset;
> +
> +	/* PPS 28, 29 */
> +	pps_sdp->pps_payload.nfl_bpg_offset =
> +		cpu_to_be16(dsc_cfg->nfl_bpg_offset);
> +
> +	/* PPS 30, 31 */
> +	pps_sdp->pps_payload.slice_bpg_offset =
> +		cpu_to_be16(dsc_cfg->slice_bpg_offset);
> +
> +	/* PPS 32, 33 */
> +	pps_sdp->pps_payload.initial_offset =
> +		cpu_to_be16(dsc_cfg->initial_offset);
> +
> +	/* PPS 34, 35 */
> +	pps_sdp->pps_payload.final_offset = cpu_to_be16(dsc_cfg->final_offset);
> +
> +	/* PPS 36 */
> +	pps_sdp->pps_payload.flatness_min_qp = (u8)dsc_cfg->flatness_min_qp;
> +
> +	/* PPS 37 */
> +	pps_sdp->pps_payload.flatness_max_qp = (u8)dsc_cfg->flatness_max_qp;
> +
> +	/* PPS 38, 39 */
> +	pps_sdp->pps_payload.rc_model_size =
> +		cpu_to_be16((u16)DSC_RC_MODEL_SIZE_CONST);
> +
> +	/* PPS 40 */
> +	pps_sdp->pps_payload.rc_edge_factor = (u8)DSC_RC_EDGE_FACTOR_CONST;
> +
> +	/* PPS 41 */
> +	pps_sdp->pps_payload.rc_quant_incr_limit0 =
> +		(u8)dsc_cfg->rc_quant_incr_limit0;
> +
> +	/* PPS 42 */
> +	pps_sdp->pps_payload.rc_quant_incr_limit1 =
> +		(u8)dsc_cfg->rc_quant_incr_limit1;
> +
> +	/* PPS 43 */
> +	pps_sdp->pps_payload.rc_tgt_offset = (u8)DSC_RC_TGT_OFFSET_LO_CONST |
> +		(u8)DSC_RC_TGT_OFFSET_HI_CONST << DSC_PPS_RC_TGT_OFFSET_HI_SHIFT;
> +
> +	/* PPS 44 - 57 */
> +	for (i = 0; i < DSC_NUM_BUF_RANGES - 1; i++)

Is the -1 correct? The loop below doesn't have it.

> +		pps_sdp->pps_payload.rc_buf_thresh[i] =
> +			dsc_cfg->rc_buf_thresh[i];
> +
> +	/* PPS 58 - 87 */
> +	/*
> +	 * For DSC sink programming the RC Range parameter fields
> +	 * are as follows: Min_qp[15:11], max_qp[10:6], offset[5:0]
> +	 */
> +	for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
> +		pps_sdp->pps_payload.rc_range_parameters[i] =
> +			(u16)((dsc_cfg->rc_range_params[i].range_min_qp <<
> +			       DSC_PPS_RC_RANGE_MINQP_SHIFT) |
> +			      (dsc_cfg->rc_range_params[i].range_max_qp <<
> +			       DSC_PPS_RC_RANGE_MAXQP_SHIFT) |
> +			      (dsc_cfg->rc_range_params[i].range_bpg_offset));
> +		pps_sdp->pps_payload.rc_range_parameters[i] =
> +			cpu_to_be16(pps_sdp->pps_payload.rc_range_parameters[i]);
> +	}
> +
> +	/* PPS 88 */
> +	pps_sdp->pps_payload.native_422_420 = (u8)dsc_cfg->native_422 |
> +		(u8)dsc_cfg->native_420 << DSC_PPS_NATIVE_420_SHIFT;
> +
> +	/* PPS 89 */
> +	pps_sdp->pps_payload.second_line_bpg_offset =
> +		(u8)dsc_cfg->second_line_bpg_offset;
> +
> +	/* PPS 90, 91 */
> +	pps_sdp->pps_payload.nsl_bpg_offset =
> +		cpu_to_be16(dsc_cfg->nsl_bpg_offset);
> +
> +	/* PPS 92, 93 */
> +	pps_sdp->pps_payload.second_line_offset_adj =
> +		cpu_to_be16(dsc_cfg->second_line_offset_adj);
> +
> +	/* PPS 94 - 127 are O */
> +}
> +EXPORT_SYMBOL(drm_dsc_pps_infoframe_pack);
> diff --git a/include/drm/drm_dsc.h b/include/drm/drm_dsc.h
> index 986f962f38d4..0e5e3368d645 100644
> --- a/include/drm/drm_dsc.h
> +++ b/include/drm/drm_dsc.h
> @@ -8,6 +8,7 @@
>  #ifndef DRM_DSC_H_
>  #define DRM_DSC_H_
>  
> +#include <linux/byteorder/generic.h>

This header doesn't need that AFAICS.

>  #include <drm/drm_dp_helper.h>
>  
>  /* VESA Display Stream Compression DSC 1.2 constants */
> @@ -24,6 +25,23 @@
>  #define DSC_RC_TGT_OFFSET_HI_CONST	    3
>  #define DSC_RC_TGT_OFFSET_LO_CONST	    3
>  
> +/* DSC PPS constants and macros */
> +#define DSC_PPS_VERSION_MAJOR_SHIFT		4
> +#define DSC_PPS_BPC_SHIFT			4
> +#define DSC_PPS_MSB_SHIFT			8
> +#define DSC_PPS_LSB_MASK			(0xFF << 0)
> +#define DSC_PPS_BPP_HIGH_MASK			(0x3 << 8)
> +#define DSC_PPS_VBR_EN_SHIFT			2
> +#define DSC_PPS_SIMPLE422_SHIFT			3
> +#define DSC_PPS_CONVERT_RGB_SHIFT		4
> +#define DSC_PPS_BLOCK_PRED_EN_SHIFT		5
> +#define DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK	(0x3 << 8)
> +#define DSC_PPS_SCALE_DEC_INT_HIGH_MASK		(0xF << 8)
> +#define DSC_PPS_RC_TGT_OFFSET_HI_SHIFT		4
> +#define DSC_PPS_RC_RANGE_MINQP_SHIFT		11
> +#define DSC_PPS_RC_RANGE_MAXQP_SHIFT		6
> +#define DSC_PPS_NATIVE_420_SHIFT		1
> +
>  /* Configuration for a single Rate Control model range */
>  struct dsc_rc_range_parameters {
>  	/* Min Quantization Parameters allowed for this range */
> @@ -463,4 +481,8 @@ struct drm_dsc_pps_infoframe {
>  	struct picture_parameter_set pps_payload;
>  } __packed;
>  
> +void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp);
> +void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
> +				struct drm_dsc_config *dsc_cfg);
> +
>  #endif /* _DRM_DSC_H_ */
> -- 
> 2.18.0
Navare, Manasi Nov. 1, 2018, 11:54 p.m. UTC | #2
Thanks for reviewing this patch. Find some comments inline

On Thu, Nov 01, 2018 at 06:46:28PM +0200, Ville Syrjälä wrote:
> On Wed, Oct 24, 2018 at 03:28:23PM -0700, Manasi Navare wrote:
> > According to Display Stream compression spec 1.2, the picture
> > parameter set metadata is sent from source to sink device
> > using the DP Secondary data packet. An infoframe is formed
> > for the PPS SDP header and PPS SDP payload bytes.
> > This patch adds helpers to fill the PPS SDP header
> > and PPS SDP payload according to the DSC 1.2 specification.
> > 
> > v6:
> > * Use proper sequence points for breaking down the
> > assignments (Chris Wilson)
> > * Use SPDX identifier
> > v5:
> > Do not use bitfields for DRM structs (Jani N)
> > v4:
> > * Use DSC constants for params that dont change across
> > configurations
> > v3:
> > * Add reference to added kernel-docs in Documentation/gpu/drm-kms-helpers.rst
> > (Daniel Vetter)
> > 
> > v2:
> > * Add EXPORT_SYMBOL for the drm functions (Manasi)
> > 
> > Cc: dri-devel@lists.freedesktop.org
> > Cc: Jani Nikula <jani.nikula@linux.intel.com>
> > Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
> > Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
> > Cc: Harry Wentland <harry.wentland@amd.com>
> > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> > Acked-by: Harry Wentland <harry.wentland@amd.com>
> > ---
> >  Documentation/gpu/drm-kms-helpers.rst |  12 ++
> >  drivers/gpu/drm/Makefile              |   2 +-
> >  drivers/gpu/drm/drm_dsc.c             | 223 ++++++++++++++++++++++++++
> >  include/drm/drm_dsc.h                 |  22 +++
> >  4 files changed, 258 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/gpu/drm/drm_dsc.c
> > 
> > diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
> > index 4b4dc236ef6f..b422eb8edf16 100644
> > --- a/Documentation/gpu/drm-kms-helpers.rst
> > +++ b/Documentation/gpu/drm-kms-helpers.rst
> > @@ -232,6 +232,18 @@ MIPI DSI Helper Functions Reference
> >  .. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
> >     :export:
> >  
> > +Display Stream Compression Helper Functions Reference
> > +=====================================================
> > +
> > +.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
> > +   :doc: dsc helpers
> > +
> > +.. kernel-doc:: include/drm/drm_dsc.h
> > +   :internal:
> > +
> > +.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
> > +   :export:
> > +
> >  Output Probing Helper Functions Reference
> >  =========================================
> >  
> > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> > index 576ba985e138..3a3e6fb6d476 100644
> > --- a/drivers/gpu/drm/Makefile
> > +++ b/drivers/gpu/drm/Makefile
> > @@ -32,7 +32,7 @@ drm-$(CONFIG_AGP) += drm_agpsupport.o
> >  drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
> >  drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
> >  
> > -drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \
> > +drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper.o \
> >  		drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \
> >  		drm_kms_helper_common.o drm_dp_dual_mode_helper.o \
> >  		drm_simple_kms_helper.o drm_modeset_helper.o \
> > diff --git a/drivers/gpu/drm/drm_dsc.c b/drivers/gpu/drm/drm_dsc.c
> > new file mode 100644
> > index 000000000000..21ae8d015afd
> > --- /dev/null
> > +++ b/drivers/gpu/drm/drm_dsc.c
> > @@ -0,0 +1,223 @@
> > +// SPDX-License-Identifier: MIT
> > +/*
> > + * Copyright © 2018 Intel Corp
> > + *
> > + * Author:
> > + * Manasi Navare <manasi.d.navare@intel.com>
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/init.h>
> > +#include <linux/errno.h>
> > +#include <drm/drm_dp_helper.h>
> > +#include <drm/drm_dsc.h>
> > +
> > +/**
> > + * DOC: dsc helpers
> > + *
> > + * These functions contain some common logic and helpers to deal with VESA
> > + * Display Stream Compression standard required for DSC on Display Port/eDP or
> > + * MIPI display interfaces.
> > + */
> > +
> > +/**
> > + * drm_dsc_dp_pps_header_init() - Initializes the PPS Header
> > + * for DisplayPort as per the DP 1.4 spec.
> > + * @pps_sdp: Secondary data packet for DSC Picture Parameter Set
> > + */
> > +void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp)
> > +{
> > +	memset(&pps_sdp->pps_header, 0, sizeof(pps_sdp->pps_header));
> > +
> > +	pps_sdp->pps_header.HB1 = DP_SDP_PPS;
> > +	pps_sdp->pps_header.HB2 = DP_SDP_PPS_HEADER_PAYLOAD_BYTES_MINUS_1;
> > +}
> > +EXPORT_SYMBOL(drm_dsc_dp_pps_header_init);
> > +
> > +/**
> > + * drm_dsc_pps_infoframe_pack() - Populates the DSC PPS infoframe
> > + * using the DSC configuration parameters in the order expected
> > + * by the DSC Display Sink device. For the DSC, the sink device
> > + * expects the PPS payload in the big endian format for the fields
> > + * that span more than 1 byte.
> > + *
> > + * @pps_sdp:
> > + * Secondary data packet for DSC Picture Parameter Set
> > + * @dsc_cfg:
> > + * DSC Configuration data filled by driver
> > + */
> > +void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
> > +				struct drm_dsc_config *dsc_cfg)
> > +{
> > +	u8 i = 0;
> 
> int i;

Ok will do,

> 
> > +
> > +	memset(&pps_sdp->pps_payload, 0, sizeof(pps_sdp->pps_payload));
> > +
> > +	/* PPS 0 */
> > +	pps_sdp->pps_payload.dsc_version =
> > +		dsc_cfg->dsc_version_minor |
> > +		dsc_cfg->dsc_version_major << DSC_PPS_VERSION_MAJOR_SHIFT;
> > +
> > +	/* PPS 1, 2 is 0 */
> > +
> > +	/* PPS 3 */
> > +	pps_sdp->pps_payload.pps_3 =
> > +		dsc_cfg->line_buf_depth |
> > +		dsc_cfg->bits_per_component << DSC_PPS_BPC_SHIFT;
> > +
> > +	/* PPS 4 */
> > +	pps_sdp->pps_payload.pps_4 =
> > +		(u8)((dsc_cfg->bits_per_pixel & DSC_PPS_BPP_HIGH_MASK) >>
> > +		     DSC_PPS_MSB_SHIFT) |
> > +		(u8)dsc_cfg->vbr_enable << DSC_PPS_VBR_EN_SHIFT |
> > +		(u8)dsc_cfg->enable422 << DSC_PPS_SIMPLE422_SHIFT |
> > +		(u8)dsc_cfg->convert_rgb << DSC_PPS_CONVERT_RGB_SHIFT |
> > +		(u8)dsc_cfg->block_pred_enable << DSC_PPS_BLOCK_PRED_EN_SHIFT;
> 
> What's with all the (u8) casts?

Since we are assigning to u8 value we dont need type cast, will remove it.

> 
> > +
> > +	/* PPS 5 */
> > +	pps_sdp->pps_payload.bits_per_pixel_low =
> > +		(u8)(dsc_cfg->bits_per_pixel & DSC_PPS_LSB_MASK);
> > +
> > +	/*
> > +	 * The DSC panel expects the PPS packet to have big endian format
> > +	 * for data spanning 2 bytes. Use a macro cpu_to_be16() to convert
> > +	 * to big endian format. If format is little endian, it will swap
> > +	 * bytes to convert to Big endian else keep it unchanged.
> > +	 */
> > +
> > +	/* PPS 6, 7 */
> > +	pps_sdp->pps_payload.pic_height = cpu_to_be16(dsc_cfg->pic_height);
> > +
> > +	/* PPS 8, 9 */
> > +	pps_sdp->pps_payload.pic_width = cpu_to_be16(dsc_cfg->pic_width);
> > +
> > +	/* PPS 10, 11 */
> > +	pps_sdp->pps_payload.slice_height = cpu_to_be16(dsc_cfg->slice_height);
> > +
> > +	/* PPS 12, 13 */
> > +	pps_sdp->pps_payload.slice_width = cpu_to_be16(dsc_cfg->slice_width);
> > +
> > +	/* PPS 14, 15 */
> > +	pps_sdp->pps_payload.chunk_size = cpu_to_be16(dsc_cfg->slice_chunk_size);
> > +
> > +	/* PPS 16 */
> > +	pps_sdp->pps_payload.initial_xmit_delay_high =
> > +		(u8)((dsc_cfg->initial_xmit_delay &
> > +		      DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK) >>
> > +		     DSC_PPS_MSB_SHIFT);
> > +
> > +	/* PPS 17 */
> > +	pps_sdp->pps_payload.initial_xmit_delay_low =
> > +		(u8)(dsc_cfg->initial_xmit_delay & DSC_PPS_LSB_MASK);
> > +
> > +	/* PPS 18, 19 */
> > +	pps_sdp->pps_payload.initial_dec_delay =
> > +		cpu_to_be16(dsc_cfg->initial_dec_delay);
> > +
> > +	/* PPS 20 is 0 */
> > +
> > +	/* PPS 21 */
> > +	pps_sdp->pps_payload.initial_scale_value =
> > +		(u8)dsc_cfg->initial_scale_value;
> > +
> > +	/* PPS 22, 23 */
> > +	pps_sdp->pps_payload.scale_increment_interval =
> > +		cpu_to_be16(dsc_cfg->scale_increment_interval);
> > +
> > +	/* PPS 24 */
> > +	pps_sdp->pps_payload.scale_decrement_interval_high =
> > +		(u8)((dsc_cfg->scale_decrement_interval &
> > +		      DSC_PPS_SCALE_DEC_INT_HIGH_MASK) >>
> > +		     DSC_PPS_MSB_SHIFT);
> > +
> > +	/* PPS 25 */
> > +	pps_sdp->pps_payload.scale_decrement_interval_low =
> > +		(u8)(dsc_cfg->scale_decrement_interval & DSC_PPS_LSB_MASK);
> > +
> > +	/* PPS 26[7:0], PPS 27[7:5] RESERVED */
> > +
> > +	/* PPS 27 */
> > +	pps_sdp->pps_payload.first_line_bpg_offset =
> > +		(u8)dsc_cfg->first_line_bpg_offset;
> > +
> > +	/* PPS 28, 29 */
> > +	pps_sdp->pps_payload.nfl_bpg_offset =
> > +		cpu_to_be16(dsc_cfg->nfl_bpg_offset);
> > +
> > +	/* PPS 30, 31 */
> > +	pps_sdp->pps_payload.slice_bpg_offset =
> > +		cpu_to_be16(dsc_cfg->slice_bpg_offset);
> > +
> > +	/* PPS 32, 33 */
> > +	pps_sdp->pps_payload.initial_offset =
> > +		cpu_to_be16(dsc_cfg->initial_offset);
> > +
> > +	/* PPS 34, 35 */
> > +	pps_sdp->pps_payload.final_offset = cpu_to_be16(dsc_cfg->final_offset);
> > +
> > +	/* PPS 36 */
> > +	pps_sdp->pps_payload.flatness_min_qp = (u8)dsc_cfg->flatness_min_qp;
> > +
> > +	/* PPS 37 */
> > +	pps_sdp->pps_payload.flatness_max_qp = (u8)dsc_cfg->flatness_max_qp;
> > +
> > +	/* PPS 38, 39 */
> > +	pps_sdp->pps_payload.rc_model_size =
> > +		cpu_to_be16((u16)DSC_RC_MODEL_SIZE_CONST);
> > +
> > +	/* PPS 40 */
> > +	pps_sdp->pps_payload.rc_edge_factor = (u8)DSC_RC_EDGE_FACTOR_CONST;
> > +
> > +	/* PPS 41 */
> > +	pps_sdp->pps_payload.rc_quant_incr_limit0 =
> > +		(u8)dsc_cfg->rc_quant_incr_limit0;
> > +
> > +	/* PPS 42 */
> > +	pps_sdp->pps_payload.rc_quant_incr_limit1 =
> > +		(u8)dsc_cfg->rc_quant_incr_limit1;
> > +
> > +	/* PPS 43 */
> > +	pps_sdp->pps_payload.rc_tgt_offset = (u8)DSC_RC_TGT_OFFSET_LO_CONST |
> > +		(u8)DSC_RC_TGT_OFFSET_HI_CONST << DSC_PPS_RC_TGT_OFFSET_HI_SHIFT;
> > +
> > +	/* PPS 44 - 57 */
> > +	for (i = 0; i < DSC_NUM_BUF_RANGES - 1; i++)
> 
> Is the -1 correct? The loop below doesn't have it.
> 
> > +		pps_sdp->pps_payload.rc_buf_thresh[i] =
> > +			dsc_cfg->rc_buf_thresh[i];
> > +
> > +	/* PPS 58 - 87 */
> > +	/*
> > +	 * For DSC sink programming the RC Range parameter fields
> > +	 * are as follows: Min_qp[15:11], max_qp[10:6], offset[5:0]
> > +	 */
> > +	for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
> > +		pps_sdp->pps_payload.rc_range_parameters[i] =
> > +			(u16)((dsc_cfg->rc_range_params[i].range_min_qp <<
> > +			       DSC_PPS_RC_RANGE_MINQP_SHIFT) |
> > +			      (dsc_cfg->rc_range_params[i].range_max_qp <<
> > +			       DSC_PPS_RC_RANGE_MAXQP_SHIFT) |
> > +			      (dsc_cfg->rc_range_params[i].range_bpg_offset));
> > +		pps_sdp->pps_payload.rc_range_parameters[i] =
> > +			cpu_to_be16(pps_sdp->pps_payload.rc_range_parameters[i]);
> > +	}
> > +
> > +	/* PPS 88 */
> > +	pps_sdp->pps_payload.native_422_420 = (u8)dsc_cfg->native_422 |
> > +		(u8)dsc_cfg->native_420 << DSC_PPS_NATIVE_420_SHIFT;
> > +
> > +	/* PPS 89 */
> > +	pps_sdp->pps_payload.second_line_bpg_offset =
> > +		(u8)dsc_cfg->second_line_bpg_offset;
> > +
> > +	/* PPS 90, 91 */
> > +	pps_sdp->pps_payload.nsl_bpg_offset =
> > +		cpu_to_be16(dsc_cfg->nsl_bpg_offset);
> > +
> > +	/* PPS 92, 93 */
> > +	pps_sdp->pps_payload.second_line_offset_adj =
> > +		cpu_to_be16(dsc_cfg->second_line_offset_adj);
> > +
> > +	/* PPS 94 - 127 are O */
> > +}
> > +EXPORT_SYMBOL(drm_dsc_pps_infoframe_pack);
> > diff --git a/include/drm/drm_dsc.h b/include/drm/drm_dsc.h
> > index 986f962f38d4..0e5e3368d645 100644
> > --- a/include/drm/drm_dsc.h
> > +++ b/include/drm/drm_dsc.h
> > @@ -8,6 +8,7 @@
> >  #ifndef DRM_DSC_H_
> >  #define DRM_DSC_H_
> >  
> > +#include <linux/byteorder/generic.h>
> 
> This header doesn't need that AFAICS.
>

I will move that to drm_dsc.c

Manasi
 
> >  #include <drm/drm_dp_helper.h>
> >  
> >  /* VESA Display Stream Compression DSC 1.2 constants */
> > @@ -24,6 +25,23 @@
> >  #define DSC_RC_TGT_OFFSET_HI_CONST	    3
> >  #define DSC_RC_TGT_OFFSET_LO_CONST	    3
> >  
> > +/* DSC PPS constants and macros */
> > +#define DSC_PPS_VERSION_MAJOR_SHIFT		4
> > +#define DSC_PPS_BPC_SHIFT			4
> > +#define DSC_PPS_MSB_SHIFT			8
> > +#define DSC_PPS_LSB_MASK			(0xFF << 0)
> > +#define DSC_PPS_BPP_HIGH_MASK			(0x3 << 8)
> > +#define DSC_PPS_VBR_EN_SHIFT			2
> > +#define DSC_PPS_SIMPLE422_SHIFT			3
> > +#define DSC_PPS_CONVERT_RGB_SHIFT		4
> > +#define DSC_PPS_BLOCK_PRED_EN_SHIFT		5
> > +#define DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK	(0x3 << 8)
> > +#define DSC_PPS_SCALE_DEC_INT_HIGH_MASK		(0xF << 8)
> > +#define DSC_PPS_RC_TGT_OFFSET_HI_SHIFT		4
> > +#define DSC_PPS_RC_RANGE_MINQP_SHIFT		11
> > +#define DSC_PPS_RC_RANGE_MAXQP_SHIFT		6
> > +#define DSC_PPS_NATIVE_420_SHIFT		1
> > +
> >  /* Configuration for a single Rate Control model range */
> >  struct dsc_rc_range_parameters {
> >  	/* Min Quantization Parameters allowed for this range */
> > @@ -463,4 +481,8 @@ struct drm_dsc_pps_infoframe {
> >  	struct picture_parameter_set pps_payload;
> >  } __packed;
> >  
> > +void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp);
> > +void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
> > +				struct drm_dsc_config *dsc_cfg);
> > +
> >  #endif /* _DRM_DSC_H_ */
> > -- 
> > 2.18.0
> 
> -- 
> Ville Syrjälä
> Intel
Navare, Manasi Nov. 2, 2018, 12:23 a.m. UTC | #3
On Thu, Nov 01, 2018 at 04:54:14PM -0700, Manasi Navare wrote:
> Thanks for reviewing this patch. Find some comments inline
> 
> On Thu, Nov 01, 2018 at 06:46:28PM +0200, Ville Syrjälä wrote:
> > On Wed, Oct 24, 2018 at 03:28:23PM -0700, Manasi Navare wrote:
> > > According to Display Stream compression spec 1.2, the picture
> > > parameter set metadata is sent from source to sink device
> > > using the DP Secondary data packet. An infoframe is formed
> > > for the PPS SDP header and PPS SDP payload bytes.
> > > This patch adds helpers to fill the PPS SDP header
> > > and PPS SDP payload according to the DSC 1.2 specification.
> > > 
> > > v6:
> > > * Use proper sequence points for breaking down the
> > > assignments (Chris Wilson)
> > > * Use SPDX identifier
> > > v5:
> > > Do not use bitfields for DRM structs (Jani N)
> > > v4:
> > > * Use DSC constants for params that dont change across
> > > configurations
> > > v3:
> > > * Add reference to added kernel-docs in Documentation/gpu/drm-kms-helpers.rst
> > > (Daniel Vetter)
> > > 
> > > v2:
> > > * Add EXPORT_SYMBOL for the drm functions (Manasi)
> > > 
> > > Cc: dri-devel@lists.freedesktop.org
> > > Cc: Jani Nikula <jani.nikula@linux.intel.com>
> > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
> > > Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
> > > Cc: Harry Wentland <harry.wentland@amd.com>
> > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> > > Acked-by: Harry Wentland <harry.wentland@amd.com>
> > > ---
> > >  Documentation/gpu/drm-kms-helpers.rst |  12 ++
> > >  drivers/gpu/drm/Makefile              |   2 +-
> > >  drivers/gpu/drm/drm_dsc.c             | 223 ++++++++++++++++++++++++++
> > >  include/drm/drm_dsc.h                 |  22 +++
> > >  4 files changed, 258 insertions(+), 1 deletion(-)
> > >  create mode 100644 drivers/gpu/drm/drm_dsc.c
> > > 
> > > diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
> > > index 4b4dc236ef6f..b422eb8edf16 100644
> > > --- a/Documentation/gpu/drm-kms-helpers.rst
> > > +++ b/Documentation/gpu/drm-kms-helpers.rst
> > > @@ -232,6 +232,18 @@ MIPI DSI Helper Functions Reference
> > >  .. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
> > >     :export:
> > >  
> > > +Display Stream Compression Helper Functions Reference
> > > +=====================================================
> > > +
> > > +.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
> > > +   :doc: dsc helpers
> > > +
> > > +.. kernel-doc:: include/drm/drm_dsc.h
> > > +   :internal:
> > > +
> > > +.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
> > > +   :export:
> > > +
> > >  Output Probing Helper Functions Reference
> > >  =========================================
> > >  
> > > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> > > index 576ba985e138..3a3e6fb6d476 100644
> > > --- a/drivers/gpu/drm/Makefile
> > > +++ b/drivers/gpu/drm/Makefile
> > > @@ -32,7 +32,7 @@ drm-$(CONFIG_AGP) += drm_agpsupport.o
> > >  drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
> > >  drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
> > >  
> > > -drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \
> > > +drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper.o \
> > >  		drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \
> > >  		drm_kms_helper_common.o drm_dp_dual_mode_helper.o \
> > >  		drm_simple_kms_helper.o drm_modeset_helper.o \
> > > diff --git a/drivers/gpu/drm/drm_dsc.c b/drivers/gpu/drm/drm_dsc.c
> > > new file mode 100644
> > > index 000000000000..21ae8d015afd
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/drm_dsc.c
> > > @@ -0,0 +1,223 @@
> > > +// SPDX-License-Identifier: MIT
> > > +/*
> > > + * Copyright © 2018 Intel Corp
> > > + *
> > > + * Author:
> > > + * Manasi Navare <manasi.d.navare@intel.com>
> > > + */
> > > +
> > > +#include <linux/kernel.h>
> > > +#include <linux/module.h>
> > > +#include <linux/init.h>
> > > +#include <linux/errno.h>
> > > +#include <drm/drm_dp_helper.h>
> > > +#include <drm/drm_dsc.h>
> > > +
> > > +/**
> > > + * DOC: dsc helpers
> > > + *
> > > + * These functions contain some common logic and helpers to deal with VESA
> > > + * Display Stream Compression standard required for DSC on Display Port/eDP or
> > > + * MIPI display interfaces.
> > > + */
> > > +
> > > +/**
> > > + * drm_dsc_dp_pps_header_init() - Initializes the PPS Header
> > > + * for DisplayPort as per the DP 1.4 spec.
> > > + * @pps_sdp: Secondary data packet for DSC Picture Parameter Set
> > > + */
> > > +void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp)
> > > +{
> > > +	memset(&pps_sdp->pps_header, 0, sizeof(pps_sdp->pps_header));
> > > +
> > > +	pps_sdp->pps_header.HB1 = DP_SDP_PPS;
> > > +	pps_sdp->pps_header.HB2 = DP_SDP_PPS_HEADER_PAYLOAD_BYTES_MINUS_1;
> > > +}
> > > +EXPORT_SYMBOL(drm_dsc_dp_pps_header_init);
> > > +
> > > +/**
> > > + * drm_dsc_pps_infoframe_pack() - Populates the DSC PPS infoframe
> > > + * using the DSC configuration parameters in the order expected
> > > + * by the DSC Display Sink device. For the DSC, the sink device
> > > + * expects the PPS payload in the big endian format for the fields
> > > + * that span more than 1 byte.
> > > + *
> > > + * @pps_sdp:
> > > + * Secondary data packet for DSC Picture Parameter Set
> > > + * @dsc_cfg:
> > > + * DSC Configuration data filled by driver
> > > + */
> > > +void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
> > > +				struct drm_dsc_config *dsc_cfg)
> > > +{
> > > +	u8 i = 0;
> > 
> > int i;
> 
> Ok will do,
> 
> > 
> > > +
> > > +	memset(&pps_sdp->pps_payload, 0, sizeof(pps_sdp->pps_payload));
> > > +
> > > +	/* PPS 0 */
> > > +	pps_sdp->pps_payload.dsc_version =
> > > +		dsc_cfg->dsc_version_minor |
> > > +		dsc_cfg->dsc_version_major << DSC_PPS_VERSION_MAJOR_SHIFT;
> > > +
> > > +	/* PPS 1, 2 is 0 */
> > > +
> > > +	/* PPS 3 */
> > > +	pps_sdp->pps_payload.pps_3 =
> > > +		dsc_cfg->line_buf_depth |
> > > +		dsc_cfg->bits_per_component << DSC_PPS_BPC_SHIFT;
> > > +
> > > +	/* PPS 4 */
> > > +	pps_sdp->pps_payload.pps_4 =
> > > +		(u8)((dsc_cfg->bits_per_pixel & DSC_PPS_BPP_HIGH_MASK) >>
> > > +		     DSC_PPS_MSB_SHIFT) |
> > > +		(u8)dsc_cfg->vbr_enable << DSC_PPS_VBR_EN_SHIFT |
> > > +		(u8)dsc_cfg->enable422 << DSC_PPS_SIMPLE422_SHIFT |
> > > +		(u8)dsc_cfg->convert_rgb << DSC_PPS_CONVERT_RGB_SHIFT |
> > > +		(u8)dsc_cfg->block_pred_enable << DSC_PPS_BLOCK_PRED_EN_SHIFT;
> > 
> > What's with all the (u8) casts?
> 
> Since we are assigning to u8 value we dont need type cast, will remove it.
> 
> > 
> > > +
> > > +	/* PPS 5 */
> > > +	pps_sdp->pps_payload.bits_per_pixel_low =
> > > +		(u8)(dsc_cfg->bits_per_pixel & DSC_PPS_LSB_MASK);
> > > +
> > > +	/*
> > > +	 * The DSC panel expects the PPS packet to have big endian format
> > > +	 * for data spanning 2 bytes. Use a macro cpu_to_be16() to convert
> > > +	 * to big endian format. If format is little endian, it will swap
> > > +	 * bytes to convert to Big endian else keep it unchanged.
> > > +	 */
> > > +
> > > +	/* PPS 6, 7 */
> > > +	pps_sdp->pps_payload.pic_height = cpu_to_be16(dsc_cfg->pic_height);
> > > +
> > > +	/* PPS 8, 9 */
> > > +	pps_sdp->pps_payload.pic_width = cpu_to_be16(dsc_cfg->pic_width);
> > > +
> > > +	/* PPS 10, 11 */
> > > +	pps_sdp->pps_payload.slice_height = cpu_to_be16(dsc_cfg->slice_height);
> > > +
> > > +	/* PPS 12, 13 */
> > > +	pps_sdp->pps_payload.slice_width = cpu_to_be16(dsc_cfg->slice_width);
> > > +
> > > +	/* PPS 14, 15 */
> > > +	pps_sdp->pps_payload.chunk_size = cpu_to_be16(dsc_cfg->slice_chunk_size);
> > > +
> > > +	/* PPS 16 */
> > > +	pps_sdp->pps_payload.initial_xmit_delay_high =
> > > +		(u8)((dsc_cfg->initial_xmit_delay &
> > > +		      DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK) >>
> > > +		     DSC_PPS_MSB_SHIFT);
> > > +
> > > +	/* PPS 17 */
> > > +	pps_sdp->pps_payload.initial_xmit_delay_low =
> > > +		(u8)(dsc_cfg->initial_xmit_delay & DSC_PPS_LSB_MASK);
> > > +
> > > +	/* PPS 18, 19 */
> > > +	pps_sdp->pps_payload.initial_dec_delay =
> > > +		cpu_to_be16(dsc_cfg->initial_dec_delay);
> > > +
> > > +	/* PPS 20 is 0 */
> > > +
> > > +	/* PPS 21 */
> > > +	pps_sdp->pps_payload.initial_scale_value =
> > > +		(u8)dsc_cfg->initial_scale_value;
> > > +
> > > +	/* PPS 22, 23 */
> > > +	pps_sdp->pps_payload.scale_increment_interval =
> > > +		cpu_to_be16(dsc_cfg->scale_increment_interval);
> > > +
> > > +	/* PPS 24 */
> > > +	pps_sdp->pps_payload.scale_decrement_interval_high =
> > > +		(u8)((dsc_cfg->scale_decrement_interval &
> > > +		      DSC_PPS_SCALE_DEC_INT_HIGH_MASK) >>
> > > +		     DSC_PPS_MSB_SHIFT);
> > > +
> > > +	/* PPS 25 */
> > > +	pps_sdp->pps_payload.scale_decrement_interval_low =
> > > +		(u8)(dsc_cfg->scale_decrement_interval & DSC_PPS_LSB_MASK);
> > > +
> > > +	/* PPS 26[7:0], PPS 27[7:5] RESERVED */
> > > +
> > > +	/* PPS 27 */
> > > +	pps_sdp->pps_payload.first_line_bpg_offset =
> > > +		(u8)dsc_cfg->first_line_bpg_offset;
> > > +
> > > +	/* PPS 28, 29 */
> > > +	pps_sdp->pps_payload.nfl_bpg_offset =
> > > +		cpu_to_be16(dsc_cfg->nfl_bpg_offset);
> > > +
> > > +	/* PPS 30, 31 */
> > > +	pps_sdp->pps_payload.slice_bpg_offset =
> > > +		cpu_to_be16(dsc_cfg->slice_bpg_offset);
> > > +
> > > +	/* PPS 32, 33 */
> > > +	pps_sdp->pps_payload.initial_offset =
> > > +		cpu_to_be16(dsc_cfg->initial_offset);
> > > +
> > > +	/* PPS 34, 35 */
> > > +	pps_sdp->pps_payload.final_offset = cpu_to_be16(dsc_cfg->final_offset);
> > > +
> > > +	/* PPS 36 */
> > > +	pps_sdp->pps_payload.flatness_min_qp = (u8)dsc_cfg->flatness_min_qp;
> > > +
> > > +	/* PPS 37 */
> > > +	pps_sdp->pps_payload.flatness_max_qp = (u8)dsc_cfg->flatness_max_qp;
> > > +
> > > +	/* PPS 38, 39 */
> > > +	pps_sdp->pps_payload.rc_model_size =
> > > +		cpu_to_be16((u16)DSC_RC_MODEL_SIZE_CONST);
> > > +
> > > +	/* PPS 40 */
> > > +	pps_sdp->pps_payload.rc_edge_factor = (u8)DSC_RC_EDGE_FACTOR_CONST;
> > > +
> > > +	/* PPS 41 */
> > > +	pps_sdp->pps_payload.rc_quant_incr_limit0 =
> > > +		(u8)dsc_cfg->rc_quant_incr_limit0;
> > > +
> > > +	/* PPS 42 */
> > > +	pps_sdp->pps_payload.rc_quant_incr_limit1 =
> > > +		(u8)dsc_cfg->rc_quant_incr_limit1;
> > > +
> > > +	/* PPS 43 */
> > > +	pps_sdp->pps_payload.rc_tgt_offset = (u8)DSC_RC_TGT_OFFSET_LO_CONST |
> > > +		(u8)DSC_RC_TGT_OFFSET_HI_CONST << DSC_PPS_RC_TGT_OFFSET_HI_SHIFT;
> > > +
> > > +	/* PPS 44 - 57 */
> > > +	for (i = 0; i < DSC_NUM_BUF_RANGES - 1; i++)
> > 
> > Is the -1 correct? The loop below doesn't have it.

Forgot to address this. So this -1 is correct since there are only 14 RC_Buf_thresh values
as per the DSC spec Table 4-2 so it is 0 - 13.
DSC_NUM_BUF_RANGES is defined as 15

while rc_range_parameters there are 15 values so there is no -1 in below loop.

Manasi

> > 
> > > +		pps_sdp->pps_payload.rc_buf_thresh[i] =
> > > +			dsc_cfg->rc_buf_thresh[i];
> > > +
> > > +	/* PPS 58 - 87 */
> > > +	/*
> > > +	 * For DSC sink programming the RC Range parameter fields
> > > +	 * are as follows: Min_qp[15:11], max_qp[10:6], offset[5:0]
> > > +	 */
> > > +	for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
> > > +		pps_sdp->pps_payload.rc_range_parameters[i] =
> > > +			(u16)((dsc_cfg->rc_range_params[i].range_min_qp <<
> > > +			       DSC_PPS_RC_RANGE_MINQP_SHIFT) |
> > > +			      (dsc_cfg->rc_range_params[i].range_max_qp <<
> > > +			       DSC_PPS_RC_RANGE_MAXQP_SHIFT) |
> > > +			      (dsc_cfg->rc_range_params[i].range_bpg_offset));
> > > +		pps_sdp->pps_payload.rc_range_parameters[i] =
> > > +			cpu_to_be16(pps_sdp->pps_payload.rc_range_parameters[i]);
> > > +	}
> > > +
> > > +	/* PPS 88 */
> > > +	pps_sdp->pps_payload.native_422_420 = (u8)dsc_cfg->native_422 |
> > > +		(u8)dsc_cfg->native_420 << DSC_PPS_NATIVE_420_SHIFT;
> > > +
> > > +	/* PPS 89 */
> > > +	pps_sdp->pps_payload.second_line_bpg_offset =
> > > +		(u8)dsc_cfg->second_line_bpg_offset;
> > > +
> > > +	/* PPS 90, 91 */
> > > +	pps_sdp->pps_payload.nsl_bpg_offset =
> > > +		cpu_to_be16(dsc_cfg->nsl_bpg_offset);
> > > +
> > > +	/* PPS 92, 93 */
> > > +	pps_sdp->pps_payload.second_line_offset_adj =
> > > +		cpu_to_be16(dsc_cfg->second_line_offset_adj);
> > > +
> > > +	/* PPS 94 - 127 are O */
> > > +}
> > > +EXPORT_SYMBOL(drm_dsc_pps_infoframe_pack);
> > > diff --git a/include/drm/drm_dsc.h b/include/drm/drm_dsc.h
> > > index 986f962f38d4..0e5e3368d645 100644
> > > --- a/include/drm/drm_dsc.h
> > > +++ b/include/drm/drm_dsc.h
> > > @@ -8,6 +8,7 @@
> > >  #ifndef DRM_DSC_H_
> > >  #define DRM_DSC_H_
> > >  
> > > +#include <linux/byteorder/generic.h>
> > 
> > This header doesn't need that AFAICS.
> >
> 
> I will move that to drm_dsc.c
> 
> Manasi
>  
> > >  #include <drm/drm_dp_helper.h>
> > >  
> > >  /* VESA Display Stream Compression DSC 1.2 constants */
> > > @@ -24,6 +25,23 @@
> > >  #define DSC_RC_TGT_OFFSET_HI_CONST	    3
> > >  #define DSC_RC_TGT_OFFSET_LO_CONST	    3
> > >  
> > > +/* DSC PPS constants and macros */
> > > +#define DSC_PPS_VERSION_MAJOR_SHIFT		4
> > > +#define DSC_PPS_BPC_SHIFT			4
> > > +#define DSC_PPS_MSB_SHIFT			8
> > > +#define DSC_PPS_LSB_MASK			(0xFF << 0)
> > > +#define DSC_PPS_BPP_HIGH_MASK			(0x3 << 8)
> > > +#define DSC_PPS_VBR_EN_SHIFT			2
> > > +#define DSC_PPS_SIMPLE422_SHIFT			3
> > > +#define DSC_PPS_CONVERT_RGB_SHIFT		4
> > > +#define DSC_PPS_BLOCK_PRED_EN_SHIFT		5
> > > +#define DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK	(0x3 << 8)
> > > +#define DSC_PPS_SCALE_DEC_INT_HIGH_MASK		(0xF << 8)
> > > +#define DSC_PPS_RC_TGT_OFFSET_HI_SHIFT		4
> > > +#define DSC_PPS_RC_RANGE_MINQP_SHIFT		11
> > > +#define DSC_PPS_RC_RANGE_MAXQP_SHIFT		6
> > > +#define DSC_PPS_NATIVE_420_SHIFT		1
> > > +
> > >  /* Configuration for a single Rate Control model range */
> > >  struct dsc_rc_range_parameters {
> > >  	/* Min Quantization Parameters allowed for this range */
> > > @@ -463,4 +481,8 @@ struct drm_dsc_pps_infoframe {
> > >  	struct picture_parameter_set pps_payload;
> > >  } __packed;
> > >  
> > > +void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp);
> > > +void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
> > > +				struct drm_dsc_config *dsc_cfg);
> > > +
> > >  #endif /* _DRM_DSC_H_ */
> > > -- 
> > > 2.18.0
> > 
> > -- 
> > Ville Syrjälä
> > Intel
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff mbox series

Patch

diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
index 4b4dc236ef6f..b422eb8edf16 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -232,6 +232,18 @@  MIPI DSI Helper Functions Reference
 .. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
    :export:
 
+Display Stream Compression Helper Functions Reference
+=====================================================
+
+.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
+   :doc: dsc helpers
+
+.. kernel-doc:: include/drm/drm_dsc.h
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
+   :export:
+
 Output Probing Helper Functions Reference
 =========================================
 
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 576ba985e138..3a3e6fb6d476 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -32,7 +32,7 @@  drm-$(CONFIG_AGP) += drm_agpsupport.o
 drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o
 drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
 
-drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \
+drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper.o \
 		drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \
 		drm_kms_helper_common.o drm_dp_dual_mode_helper.o \
 		drm_simple_kms_helper.o drm_modeset_helper.o \
diff --git a/drivers/gpu/drm/drm_dsc.c b/drivers/gpu/drm/drm_dsc.c
new file mode 100644
index 000000000000..21ae8d015afd
--- /dev/null
+++ b/drivers/gpu/drm/drm_dsc.c
@@ -0,0 +1,223 @@ 
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2018 Intel Corp
+ *
+ * Author:
+ * Manasi Navare <manasi.d.navare@intel.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <drm/drm_dp_helper.h>
+#include <drm/drm_dsc.h>
+
+/**
+ * DOC: dsc helpers
+ *
+ * These functions contain some common logic and helpers to deal with VESA
+ * Display Stream Compression standard required for DSC on Display Port/eDP or
+ * MIPI display interfaces.
+ */
+
+/**
+ * drm_dsc_dp_pps_header_init() - Initializes the PPS Header
+ * for DisplayPort as per the DP 1.4 spec.
+ * @pps_sdp: Secondary data packet for DSC Picture Parameter Set
+ */
+void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp)
+{
+	memset(&pps_sdp->pps_header, 0, sizeof(pps_sdp->pps_header));
+
+	pps_sdp->pps_header.HB1 = DP_SDP_PPS;
+	pps_sdp->pps_header.HB2 = DP_SDP_PPS_HEADER_PAYLOAD_BYTES_MINUS_1;
+}
+EXPORT_SYMBOL(drm_dsc_dp_pps_header_init);
+
+/**
+ * drm_dsc_pps_infoframe_pack() - Populates the DSC PPS infoframe
+ * using the DSC configuration parameters in the order expected
+ * by the DSC Display Sink device. For the DSC, the sink device
+ * expects the PPS payload in the big endian format for the fields
+ * that span more than 1 byte.
+ *
+ * @pps_sdp:
+ * Secondary data packet for DSC Picture Parameter Set
+ * @dsc_cfg:
+ * DSC Configuration data filled by driver
+ */
+void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
+				struct drm_dsc_config *dsc_cfg)
+{
+	u8 i = 0;
+
+	memset(&pps_sdp->pps_payload, 0, sizeof(pps_sdp->pps_payload));
+
+	/* PPS 0 */
+	pps_sdp->pps_payload.dsc_version =
+		dsc_cfg->dsc_version_minor |
+		dsc_cfg->dsc_version_major << DSC_PPS_VERSION_MAJOR_SHIFT;
+
+	/* PPS 1, 2 is 0 */
+
+	/* PPS 3 */
+	pps_sdp->pps_payload.pps_3 =
+		dsc_cfg->line_buf_depth |
+		dsc_cfg->bits_per_component << DSC_PPS_BPC_SHIFT;
+
+	/* PPS 4 */
+	pps_sdp->pps_payload.pps_4 =
+		(u8)((dsc_cfg->bits_per_pixel & DSC_PPS_BPP_HIGH_MASK) >>
+		     DSC_PPS_MSB_SHIFT) |
+		(u8)dsc_cfg->vbr_enable << DSC_PPS_VBR_EN_SHIFT |
+		(u8)dsc_cfg->enable422 << DSC_PPS_SIMPLE422_SHIFT |
+		(u8)dsc_cfg->convert_rgb << DSC_PPS_CONVERT_RGB_SHIFT |
+		(u8)dsc_cfg->block_pred_enable << DSC_PPS_BLOCK_PRED_EN_SHIFT;
+
+	/* PPS 5 */
+	pps_sdp->pps_payload.bits_per_pixel_low =
+		(u8)(dsc_cfg->bits_per_pixel & DSC_PPS_LSB_MASK);
+
+	/*
+	 * The DSC panel expects the PPS packet to have big endian format
+	 * for data spanning 2 bytes. Use a macro cpu_to_be16() to convert
+	 * to big endian format. If format is little endian, it will swap
+	 * bytes to convert to Big endian else keep it unchanged.
+	 */
+
+	/* PPS 6, 7 */
+	pps_sdp->pps_payload.pic_height = cpu_to_be16(dsc_cfg->pic_height);
+
+	/* PPS 8, 9 */
+	pps_sdp->pps_payload.pic_width = cpu_to_be16(dsc_cfg->pic_width);
+
+	/* PPS 10, 11 */
+	pps_sdp->pps_payload.slice_height = cpu_to_be16(dsc_cfg->slice_height);
+
+	/* PPS 12, 13 */
+	pps_sdp->pps_payload.slice_width = cpu_to_be16(dsc_cfg->slice_width);
+
+	/* PPS 14, 15 */
+	pps_sdp->pps_payload.chunk_size = cpu_to_be16(dsc_cfg->slice_chunk_size);
+
+	/* PPS 16 */
+	pps_sdp->pps_payload.initial_xmit_delay_high =
+		(u8)((dsc_cfg->initial_xmit_delay &
+		      DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK) >>
+		     DSC_PPS_MSB_SHIFT);
+
+	/* PPS 17 */
+	pps_sdp->pps_payload.initial_xmit_delay_low =
+		(u8)(dsc_cfg->initial_xmit_delay & DSC_PPS_LSB_MASK);
+
+	/* PPS 18, 19 */
+	pps_sdp->pps_payload.initial_dec_delay =
+		cpu_to_be16(dsc_cfg->initial_dec_delay);
+
+	/* PPS 20 is 0 */
+
+	/* PPS 21 */
+	pps_sdp->pps_payload.initial_scale_value =
+		(u8)dsc_cfg->initial_scale_value;
+
+	/* PPS 22, 23 */
+	pps_sdp->pps_payload.scale_increment_interval =
+		cpu_to_be16(dsc_cfg->scale_increment_interval);
+
+	/* PPS 24 */
+	pps_sdp->pps_payload.scale_decrement_interval_high =
+		(u8)((dsc_cfg->scale_decrement_interval &
+		      DSC_PPS_SCALE_DEC_INT_HIGH_MASK) >>
+		     DSC_PPS_MSB_SHIFT);
+
+	/* PPS 25 */
+	pps_sdp->pps_payload.scale_decrement_interval_low =
+		(u8)(dsc_cfg->scale_decrement_interval & DSC_PPS_LSB_MASK);
+
+	/* PPS 26[7:0], PPS 27[7:5] RESERVED */
+
+	/* PPS 27 */
+	pps_sdp->pps_payload.first_line_bpg_offset =
+		(u8)dsc_cfg->first_line_bpg_offset;
+
+	/* PPS 28, 29 */
+	pps_sdp->pps_payload.nfl_bpg_offset =
+		cpu_to_be16(dsc_cfg->nfl_bpg_offset);
+
+	/* PPS 30, 31 */
+	pps_sdp->pps_payload.slice_bpg_offset =
+		cpu_to_be16(dsc_cfg->slice_bpg_offset);
+
+	/* PPS 32, 33 */
+	pps_sdp->pps_payload.initial_offset =
+		cpu_to_be16(dsc_cfg->initial_offset);
+
+	/* PPS 34, 35 */
+	pps_sdp->pps_payload.final_offset = cpu_to_be16(dsc_cfg->final_offset);
+
+	/* PPS 36 */
+	pps_sdp->pps_payload.flatness_min_qp = (u8)dsc_cfg->flatness_min_qp;
+
+	/* PPS 37 */
+	pps_sdp->pps_payload.flatness_max_qp = (u8)dsc_cfg->flatness_max_qp;
+
+	/* PPS 38, 39 */
+	pps_sdp->pps_payload.rc_model_size =
+		cpu_to_be16((u16)DSC_RC_MODEL_SIZE_CONST);
+
+	/* PPS 40 */
+	pps_sdp->pps_payload.rc_edge_factor = (u8)DSC_RC_EDGE_FACTOR_CONST;
+
+	/* PPS 41 */
+	pps_sdp->pps_payload.rc_quant_incr_limit0 =
+		(u8)dsc_cfg->rc_quant_incr_limit0;
+
+	/* PPS 42 */
+	pps_sdp->pps_payload.rc_quant_incr_limit1 =
+		(u8)dsc_cfg->rc_quant_incr_limit1;
+
+	/* PPS 43 */
+	pps_sdp->pps_payload.rc_tgt_offset = (u8)DSC_RC_TGT_OFFSET_LO_CONST |
+		(u8)DSC_RC_TGT_OFFSET_HI_CONST << DSC_PPS_RC_TGT_OFFSET_HI_SHIFT;
+
+	/* PPS 44 - 57 */
+	for (i = 0; i < DSC_NUM_BUF_RANGES - 1; i++)
+		pps_sdp->pps_payload.rc_buf_thresh[i] =
+			dsc_cfg->rc_buf_thresh[i];
+
+	/* PPS 58 - 87 */
+	/*
+	 * For DSC sink programming the RC Range parameter fields
+	 * are as follows: Min_qp[15:11], max_qp[10:6], offset[5:0]
+	 */
+	for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
+		pps_sdp->pps_payload.rc_range_parameters[i] =
+			(u16)((dsc_cfg->rc_range_params[i].range_min_qp <<
+			       DSC_PPS_RC_RANGE_MINQP_SHIFT) |
+			      (dsc_cfg->rc_range_params[i].range_max_qp <<
+			       DSC_PPS_RC_RANGE_MAXQP_SHIFT) |
+			      (dsc_cfg->rc_range_params[i].range_bpg_offset));
+		pps_sdp->pps_payload.rc_range_parameters[i] =
+			cpu_to_be16(pps_sdp->pps_payload.rc_range_parameters[i]);
+	}
+
+	/* PPS 88 */
+	pps_sdp->pps_payload.native_422_420 = (u8)dsc_cfg->native_422 |
+		(u8)dsc_cfg->native_420 << DSC_PPS_NATIVE_420_SHIFT;
+
+	/* PPS 89 */
+	pps_sdp->pps_payload.second_line_bpg_offset =
+		(u8)dsc_cfg->second_line_bpg_offset;
+
+	/* PPS 90, 91 */
+	pps_sdp->pps_payload.nsl_bpg_offset =
+		cpu_to_be16(dsc_cfg->nsl_bpg_offset);
+
+	/* PPS 92, 93 */
+	pps_sdp->pps_payload.second_line_offset_adj =
+		cpu_to_be16(dsc_cfg->second_line_offset_adj);
+
+	/* PPS 94 - 127 are O */
+}
+EXPORT_SYMBOL(drm_dsc_pps_infoframe_pack);
diff --git a/include/drm/drm_dsc.h b/include/drm/drm_dsc.h
index 986f962f38d4..0e5e3368d645 100644
--- a/include/drm/drm_dsc.h
+++ b/include/drm/drm_dsc.h
@@ -8,6 +8,7 @@ 
 #ifndef DRM_DSC_H_
 #define DRM_DSC_H_
 
+#include <linux/byteorder/generic.h>
 #include <drm/drm_dp_helper.h>
 
 /* VESA Display Stream Compression DSC 1.2 constants */
@@ -24,6 +25,23 @@ 
 #define DSC_RC_TGT_OFFSET_HI_CONST	    3
 #define DSC_RC_TGT_OFFSET_LO_CONST	    3
 
+/* DSC PPS constants and macros */
+#define DSC_PPS_VERSION_MAJOR_SHIFT		4
+#define DSC_PPS_BPC_SHIFT			4
+#define DSC_PPS_MSB_SHIFT			8
+#define DSC_PPS_LSB_MASK			(0xFF << 0)
+#define DSC_PPS_BPP_HIGH_MASK			(0x3 << 8)
+#define DSC_PPS_VBR_EN_SHIFT			2
+#define DSC_PPS_SIMPLE422_SHIFT			3
+#define DSC_PPS_CONVERT_RGB_SHIFT		4
+#define DSC_PPS_BLOCK_PRED_EN_SHIFT		5
+#define DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK	(0x3 << 8)
+#define DSC_PPS_SCALE_DEC_INT_HIGH_MASK		(0xF << 8)
+#define DSC_PPS_RC_TGT_OFFSET_HI_SHIFT		4
+#define DSC_PPS_RC_RANGE_MINQP_SHIFT		11
+#define DSC_PPS_RC_RANGE_MAXQP_SHIFT		6
+#define DSC_PPS_NATIVE_420_SHIFT		1
+
 /* Configuration for a single Rate Control model range */
 struct dsc_rc_range_parameters {
 	/* Min Quantization Parameters allowed for this range */
@@ -463,4 +481,8 @@  struct drm_dsc_pps_infoframe {
 	struct picture_parameter_set pps_payload;
 } __packed;
 
+void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp);
+void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
+				struct drm_dsc_config *dsc_cfg);
+
 #endif /* _DRM_DSC_H_ */