[Intel-gfx] [PATCH v2 4/4] drm/dsc: Add helpers for DSC picture parameter set infoframes

[Manasi Navare]

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.

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-de...@lists.freedesktop.org
Cc: Jani Nikula 
Cc: Ville Syrjala 
Cc: Anusha Srivatsa 
Signed-off-by: Manasi Navare 
---
 Documentation/gpu/drm-kms-helpers.rst |  12 ++
 drivers/gpu/drm/Makefile  |   2 +-
 drivers/gpu/drm/drm_dsc.c | 227 ++
 include/drm/drm_dsc.h |  16 +++
 4 files changed, 256 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 e37557b..13837f7 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -205,6 +205,18 @@ 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 ef9f3da..02f1b2c 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -31,7 +31,7 @@ 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 000..3bf8d42
--- /dev/null
+++ b/drivers/gpu/drm/drm_dsc.c
@@ -0,0 +1,227 @@
+/*
+ * Copyright © 2018 Intel Corp
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ *
+ * Author:
+ * Manasi Navare 
+ */
+
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+/**
+ * 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(_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 

[Intel-gfx] [PATCH v2 4/4] drm/dsc: Add helpers for DSC picture parameter set infoframes

[Manasi Navare]

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.

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

Cc: dri-de...@lists.freedesktop.org
Cc: Jani Nikula 
Cc: Ville Syrjala 
Cc: Anusha Srivatsa 
Signed-off-by: Manasi Navare 
---
 drivers/gpu/drm/Makefile  |   2 +-
 drivers/gpu/drm/drm_dsc.c | 224 ++
 include/drm/drm_dsc.h |  16 
 3 files changed, 241 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/drm_dsc.c

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index ef9f3da..02f1b2c 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -31,7 +31,7 @@ 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 000..c7b80c8
--- /dev/null
+++ b/drivers/gpu/drm/drm_dsc.c
@@ -0,0 +1,224 @@
+/*
+ * Copyright © 2018 Intel Corp
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ *
+ * Author:
+ * Manasi Navare 
+ */
+
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+/**
+ * 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(_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
+ * @big_endian: Flag to indicate if HW is Big Endian
+ */
+void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
+   struct drm_dsc_config *dsc_cfg,
+   bool is_big_endian)
+{
+   u8 i = 0;
+
+   memset(_sdp->pps_payload, 0, sizeof(pps_sdp->pps_payload));
+
+   /* PPS 0 */
+   pps_sdp->pps_payload.dsc_version_minor = dsc_cfg->dsc_version_minor;
+   pps_sdp->pps_payload.dsc_version_major = dsc_cfg->dsc_version_major;
+
+   /* PPS 1, 2 is 0 */
+
+   /* PPS 3 */
+   pps_sdp->pps_payload.linebuf_depth = dsc_cfg->line_buf_depth;
+   pps_sdp->pps_payload.bits_per_component = dsc_cfg->bits_per_component;
+
+   /* PPS 4, 5 */
+