Re: [PATCH v3 13/19] drm/msm/dp: add VSC SDP support for YUV420 over DP

Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> · Wed, 14 Feb 2024 12:15:06 -0800

On 2/14/2024 11:39 AM, Dmitry Baryshkov wrote:
On Wed, 14 Feb 2024 at 20:04, Paloma Arellano <quic_parellan@xxxxxxxxxxx> wrote:

Add support to pack and send the VSC SDP packet for DP. This therefore
allows the transmision of format information to the sinks which is
needed for YUV420 support over DP.

Changes in v3:
         - Create a new struct, msm_dp_sdp_with_parity, which holds the
           packing information for VSC SDP
         - Use drm_dp_vsc_sdp_pack() to pack the data into the new
           msm_dp_sdp_with_parity struct instead of specifically packing
           for YUV420 format
         - Modify dp_catalog_panel_send_vsc_sdp() to send the VSC SDP
           data using the new msm_dp_sdp_with_parity struct

Changes in v2:
         - Rename GENERIC0_SDPSIZE macro to GENERIC0_SDPSIZE_VALID
         - Remove dp_sdp from the dp_catalog struct since this data is
           being allocated at the point used
         - Create a new function in dp_utils to pack the VSC SDP data
           into a buffer
         - Create a new function that packs the SDP header bytes into a
           buffer. This function is made generic so that it can be
           utilized by dp_audio
           header bytes into a buffer
         - Create a new function in dp_utils that takes the packed buffer
           and writes to the DP_GENERIC0_* registers
         - Split the dp_catalog_panel_config_vsc_sdp() function into two
           to disable/enable sending VSC SDP packets
         - Check the DP HW version using the original useage of
           dp_catalog_hw_revision() and correct the version checking
           logic
         - Rename dp_panel_setup_vsc_sdp() to
           dp_panel_setup_vsc_sdp_yuv_420() to explicitly state that
           currently VSC SDP is only being set up to support YUV420 modes

Signed-off-by: Paloma Arellano <quic_parellan@xxxxxxxxxxx>
---
  drivers/gpu/drm/msm/dp/dp_catalog.c | 113 ++++++++++++++++++++++++++++
  drivers/gpu/drm/msm/dp/dp_catalog.h |   7 ++
  drivers/gpu/drm/msm/dp/dp_ctrl.c    |   4 +
  drivers/gpu/drm/msm/dp/dp_panel.c   |  55 ++++++++++++++
  drivers/gpu/drm/msm/dp/dp_reg.h     |   3 +
  drivers/gpu/drm/msm/dp/dp_utils.c   |  48 ++++++++++++
  drivers/gpu/drm/msm/dp/dp_utils.h   |  18 +++++
  7 files changed, 248 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
index 5d84c089e520a..61d5317efe683 100644
--- a/drivers/gpu/drm/msm/dp/dp_catalog.c
+++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
@@ -901,6 +901,119 @@ int dp_catalog_panel_timing_cfg(struct dp_catalog *dp_catalog)
         return 0;
  }

+static void dp_catalog_panel_send_vsc_sdp(struct dp_catalog *dp_catalog,
+                                         struct msm_dp_sdp_with_parity *msm_dp_sdp)
+{
+       struct dp_catalog_private *catalog;
+       u32 val;
+
+       if (!dp_catalog) {
+               DRM_ERROR("invalid input\n");
+               return;
+       }
+
+       catalog = container_of(dp_catalog, struct dp_catalog_private, dp_catalog);
+
+       val = ((msm_dp_sdp->vsc_sdp.sdp_header.HB0) << HEADER_BYTE_0_BIT |
+              (msm_dp_sdp->pb.PB0 << PARITY_BYTE_0_BIT) |
+              (msm_dp_sdp->vsc_sdp.sdp_header.HB1) << HEADER_BYTE_1_BIT |
+              (msm_dp_sdp->pb.PB1 << PARITY_BYTE_1_BIT));
+       dp_write_link(catalog, MMSS_DP_GENERIC0_0, val);
+
+       val = ((msm_dp_sdp->vsc_sdp.sdp_header.HB2) << HEADER_BYTE_2_BIT |
+              (msm_dp_sdp->pb.PB2 << PARITY_BYTE_2_BIT) |
+              (msm_dp_sdp->vsc_sdp.sdp_header.HB3) << HEADER_BYTE_3_BIT |
+              (msm_dp_sdp->pb.PB3 << PARITY_BYTE_3_BIT));
+       dp_write_link(catalog, MMSS_DP_GENERIC0_1, val);

I still think that this is not the way to do it. Could you please
extract the function that takes struct dp_sdp_header, calculates
padding and writes resulting data to the hardware? This way we can
reuse it later for all the dp_audio stuff.


hmmm ... dp_utils_pack_sdp_header() does that you are asking for right?

OR are you asking for another function like:

1) rename dp_utils_pack_sdp_header() to dp_utils_calc_sdp_parity()
2) dp_utils_pack_sdp() takes two u32 to pack the header and parity 
together and we move the << HEADER_BYTE_xx | part to it

dp_catalog_panel_send_vsc_sdp() just uses these two u32 to write the 
headers.


+
+       val = ((msm_dp_sdp->vsc_sdp.db[16]) | (msm_dp_sdp->vsc_sdp.db[17] << 8) |
+              (msm_dp_sdp->vsc_sdp.db[18] << 16));
+       dp_write_link(catalog, MMSS_DP_GENERIC0_6, val);

Shouldn't we write full dp_sdp data, including all zeroes? Here you
assume that there is no other data in dp_sdp and also that nobody
wrote anything senseless to those registers.


As per documentation, it says db[0] to db[15] are reserved so I thought 
its better not to touch/use them and start writing for 16 onwards.

1592  * VSC SDP Payload for Pixel Encoding/Colorimetry Format
1593  * db[0] - db[15]: Reserved
1594  * db[16]: Pixel Encoding and Colorimetry Formats
1595  * db[17]: Dynamic Range and Component Bit Depth
1596  * db[18]: Content Type
1597  * db[19] - db[31]: Reserved
1598  */

+}
+
+static void dp_catalog_panel_update_sdp(struct dp_catalog *dp_catalog)
+{
+       struct dp_catalog_private *catalog;
+       u32 hw_revision;
+
+       catalog = container_of(dp_catalog, struct dp_catalog_private, dp_catalog);
+
+       hw_revision = dp_catalog_hw_revision(dp_catalog);
+       if (hw_revision < DP_HW_VERSION_1_2 && hw_revision >= DP_HW_VERSION_1_0) {
+               dp_write_link(catalog, MMSS_DP_SDP_CFG3, 0x01);
+               dp_write_link(catalog, MMSS_DP_SDP_CFG3, 0x00);
+       }
+}
+
+void dp_catalog_panel_enable_vsc_sdp(struct dp_catalog *dp_catalog,
+                                    struct msm_dp_sdp_with_parity *msm_dp_sdp)
+{
+       struct dp_catalog_private *catalog;
+       u32 cfg, cfg2, misc;
+
+       if (!dp_catalog) {
+               DRM_ERROR("invalid input\n");
+               return;
+       }
+
+       catalog = container_of(dp_catalog, struct dp_catalog_private, dp_catalog);
+
+       cfg = dp_read_link(catalog, MMSS_DP_SDP_CFG);
+       cfg2 = dp_read_link(catalog, MMSS_DP_SDP_CFG2);
+       misc = dp_read_link(catalog, REG_DP_MISC1_MISC0);
+
+       cfg |= GEN0_SDP_EN;
+       dp_write_link(catalog, MMSS_DP_SDP_CFG, cfg);
+
+       cfg2 |= GENERIC0_SDPSIZE_VALID;
+       dp_write_link(catalog, MMSS_DP_SDP_CFG2, cfg2);
+
+       dp_catalog_panel_send_vsc_sdp(dp_catalog, msm_dp_sdp);
+
+       /* indicates presence of VSC (BIT(6) of MISC1) */
+       misc |= DP_MISC1_VSC_SDP;
+
+       drm_dbg_dp(catalog->drm_dev, "vsc sdp enable=1\n");
+
+       pr_debug("misc settings = 0x%x\n", misc);
+       dp_write_link(catalog, REG_DP_MISC1_MISC0, misc);
+
+       dp_catalog_panel_update_sdp(dp_catalog);
+}
+
+void dp_catalog_panel_disable_vsc_sdp(struct dp_catalog *dp_catalog)
+{
+       struct dp_catalog_private *catalog;
+       u32 cfg, cfg2, misc;
+
+       if (!dp_catalog) {
+               DRM_ERROR("invalid input\n");
+               return;
+       }
+
+       catalog = container_of(dp_catalog, struct dp_catalog_private, dp_catalog);
+
+       cfg = dp_read_link(catalog, MMSS_DP_SDP_CFG);
+       cfg2 = dp_read_link(catalog, MMSS_DP_SDP_CFG2);
+       misc = dp_read_link(catalog, REG_DP_MISC1_MISC0);
+
+       cfg &= ~GEN0_SDP_EN;
+       dp_write_link(catalog, MMSS_DP_SDP_CFG, cfg);
+
+       cfg2 &= ~GENERIC0_SDPSIZE_VALID;
+       dp_write_link(catalog, MMSS_DP_SDP_CFG2, cfg2);
+
+       /* switch back to MSA */
+       misc &= ~DP_MISC1_VSC_SDP;
+
+       drm_dbg_dp(catalog->drm_dev, "vsc sdp enable=0\n");
+
+       pr_debug("misc settings = 0x%x\n", misc);
+       dp_write_link(catalog, REG_DP_MISC1_MISC0, misc);
+
+       dp_catalog_panel_update_sdp(dp_catalog);
+}
+
  void dp_catalog_panel_tpg_enable(struct dp_catalog *dp_catalog,
                                 struct drm_display_mode *drm_mode)
  {
diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.h b/drivers/gpu/drm/msm/dp/dp_catalog.h
index 6cb5e2a243de2..4bf08c27a9bf3 100644
--- a/drivers/gpu/drm/msm/dp/dp_catalog.h
+++ b/drivers/gpu/drm/msm/dp/dp_catalog.h
@@ -9,6 +9,7 @@
  #include <drm/drm_modes.h>

  #include "dp_parser.h"
+#include "dp_utils.h"
  #include "disp/msm_disp_snapshot.h"

  /* interrupts */
@@ -30,6 +31,9 @@

  #define DP_AUX_CFG_MAX_VALUE_CNT 3

+#define DP_HW_VERSION_1_0      0x10000000
+#define DP_HW_VERSION_1_2      0x10020000
+
  /* PHY AUX config registers */
  enum dp_phy_aux_config_type {
         PHY_AUX_CFG0,
@@ -124,6 +128,9 @@ u32 dp_catalog_ctrl_read_phy_pattern(struct dp_catalog *dp_catalog);

  /* DP Panel APIs */
  int dp_catalog_panel_timing_cfg(struct dp_catalog *dp_catalog);
+void dp_catalog_panel_enable_vsc_sdp(struct dp_catalog *dp_catalog,
+                                    struct msm_dp_sdp_with_parity *msm_dp_sdp);
+void dp_catalog_panel_disable_vsc_sdp(struct dp_catalog *dp_catalog);
  void dp_catalog_dump_regs(struct dp_catalog *dp_catalog);
  void dp_catalog_panel_tpg_enable(struct dp_catalog *dp_catalog,
                                 struct drm_display_mode *drm_mode);
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index 209cf2a35642f..beef86b1aaf81 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1952,6 +1952,8 @@ int dp_ctrl_off_link_stream(struct dp_ctrl *dp_ctrl)
         dp_io = &ctrl->parser->io;
         phy = dp_io->phy;

+       dp_catalog_panel_disable_vsc_sdp(ctrl->catalog);
+
         /* set dongle to D3 (power off) mode */
         dp_link_psm_config(ctrl->link, &ctrl->panel->link_info, true);

@@ -2026,6 +2028,8 @@ int dp_ctrl_off(struct dp_ctrl *dp_ctrl)
         dp_io = &ctrl->parser->io;
         phy = dp_io->phy;

+       dp_catalog_panel_disable_vsc_sdp(ctrl->catalog);
+
         dp_catalog_ctrl_mainlink_ctrl(ctrl->catalog, false);

         dp_catalog_ctrl_reset(ctrl->catalog);
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
index db1942794f1a4..18420a7ba4ab3 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.c
+++ b/drivers/gpu/drm/msm/dp/dp_panel.c
@@ -4,6 +4,7 @@
   */

  #include "dp_panel.h"
+#include "dp_utils.h"

  #include <drm/drm_connector.h>
  #include <drm/drm_edid.h>
@@ -281,6 +282,56 @@ void dp_panel_tpg_config(struct dp_panel *dp_panel, bool enable)
         dp_catalog_panel_tpg_enable(catalog, &panel->dp_panel.dp_mode.drm_mode);
  }

+static int dp_panel_setup_vsc_sdp_yuv_420(struct dp_panel *dp_panel)
+{
+       struct dp_catalog *catalog;
+       struct dp_panel_private *panel;
+       struct dp_display_mode *dp_mode;
+       struct drm_dp_vsc_sdp vsc_sdp_data;
+       struct msm_dp_sdp_with_parity msm_dp_sdp;
+       ssize_t len;
+       int rc = 0;
+
+       if (!dp_panel) {
+               DRM_ERROR("invalid input\n");
+               rc = -EINVAL;
+               return rc;
+       }
+
+       panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
+       catalog = panel->catalog;
+       dp_mode = &dp_panel->dp_mode;
+
+       memset(&vsc_sdp_data, 0, sizeof(vsc_sdp_data));
+
+       /* VSC SDP header as per table 2-118 of DP 1.4 specification */
+       vsc_sdp_data.sdp_type = DP_SDP_VSC;
+       vsc_sdp_data.revision = 0x05;
+       vsc_sdp_data.length = 0x13;
+
+       /* VSC SDP Payload for DB16 */
+       vsc_sdp_data.pixelformat = DP_PIXELFORMAT_YUV420;
+       vsc_sdp_data.colorimetry = DP_COLORIMETRY_DEFAULT;
+
+       /* VSC SDP Payload for DB17 */
+       vsc_sdp_data.bpc = dp_mode->bpp / 3;
+       vsc_sdp_data.dynamic_range = DP_DYNAMIC_RANGE_CTA;
+
+       /* VSC SDP Payload for DB18 */
+       vsc_sdp_data.content_type = DP_CONTENT_TYPE_GRAPHICS;
+
+       // rc = dp_utils_pack_vsc_sdp(&vsc_sdp_data, &sdp_header, gen_buffer, buff_size);
+       len = dp_utils_pack_vsc_sdp(&vsc_sdp_data, &msm_dp_sdp);
+       if (len < 0) {
+               DRM_ERROR("unable to pack vsc sdp\n");
+               return len;
+       }
+
+       dp_catalog_panel_enable_vsc_sdp(catalog, &msm_dp_sdp);
+
+       return rc;
+}
+
  void dp_panel_dump_regs(struct dp_panel *dp_panel)
  {
         struct dp_catalog *catalog;
@@ -344,6 +395,10 @@ int dp_panel_timing_cfg(struct dp_panel *dp_panel)
         catalog->dp_active = data;

         dp_catalog_panel_timing_cfg(catalog);
+
+       if (dp_panel->dp_mode.out_fmt_is_yuv_420)
+               dp_panel_setup_vsc_sdp_yuv_420(dp_panel);
+
         panel->panel_on = true;

         return 0;
diff --git a/drivers/gpu/drm/msm/dp/dp_reg.h b/drivers/gpu/drm/msm/dp/dp_reg.h
index ea85a691e72b5..2983756c125cd 100644
--- a/drivers/gpu/drm/msm/dp/dp_reg.h
+++ b/drivers/gpu/drm/msm/dp/dp_reg.h
@@ -142,6 +142,7 @@
  #define DP_MISC0_SYNCHRONOUS_CLK               (0x00000001)
  #define DP_MISC0_COLORIMETRY_CFG_SHIFT         (0x00000001)
  #define DP_MISC0_TEST_BITS_DEPTH_SHIFT         (0x00000005)
+#define DP_MISC1_VSC_SDP                       (0x00004000)

  #define REG_DP_VALID_BOUNDARY                  (0x00000030)
  #define REG_DP_VALID_BOUNDARY_2                        (0x00000034)
@@ -201,9 +202,11 @@
  #define MMSS_DP_AUDIO_CTRL_RESET               (0x00000214)

  #define MMSS_DP_SDP_CFG                                (0x00000228)
+#define GEN0_SDP_EN                            (0x00020000)
  #define MMSS_DP_SDP_CFG2                       (0x0000022C)
  #define MMSS_DP_AUDIO_TIMESTAMP_0              (0x00000230)
  #define MMSS_DP_AUDIO_TIMESTAMP_1              (0x00000234)
+#define GENERIC0_SDPSIZE_VALID                 (0x00010000)

  #define MMSS_DP_AUDIO_STREAM_0                 (0x00000240)
  #define MMSS_DP_AUDIO_STREAM_1                 (0x00000244)
diff --git a/drivers/gpu/drm/msm/dp/dp_utils.c b/drivers/gpu/drm/msm/dp/dp_utils.c
index 3a44fe738c004..81601f3c414fc 100644
--- a/drivers/gpu/drm/msm/dp/dp_utils.c
+++ b/drivers/gpu/drm/msm/dp/dp_utils.c
@@ -4,6 +4,7 @@
   */

  #include <linux/types.h>
+#include <drm/drm_print.h>

  #include "dp_utils.h"

@@ -71,3 +72,50 @@ u8 dp_utils_calculate_parity(u32 data)

         return parity_byte;
  }
+
+ssize_t dp_utils_pack_sdp_header(struct dp_sdp_header *sdp_header, struct msm_dp_vsc_sdp_parity *pb,
+                                size_t size)
+{
+       u8 header;
+
+       size_t length = sizeof(struct msm_dp_vsc_sdp_parity);
+
+       if (size < length)
+               return -ENOSPC;
+
+       memset(pb, 0, size);
+
+       header = sdp_header->HB0;
+       pb->PB0 = dp_utils_calculate_parity(header);
+
+       header = sdp_header->HB1;
+       pb->PB1 = dp_utils_calculate_parity(header);
+
+       header = sdp_header->HB2;
+       pb->PB2 = dp_utils_calculate_parity(header);
+
+       header = sdp_header->HB3;
+       pb->PB3 = dp_utils_calculate_parity(header);
+
+       return length;
+}
+
+ssize_t dp_utils_pack_vsc_sdp(struct drm_dp_vsc_sdp *vsc, struct msm_dp_sdp_with_parity *msm_dp_sdp)
+{
+       ssize_t len;
+
+       len = drm_dp_vsc_sdp_pack(vsc, &msm_dp_sdp->vsc_sdp, sizeof(msm_dp_sdp->vsc_sdp));
+       if (len < 0) {
+               DRM_ERROR("unable to pack vsc sdp\n");
+               return len;
+       }
+
+       len = dp_utils_pack_sdp_header(&msm_dp_sdp->vsc_sdp.sdp_header, &msm_dp_sdp->pb,
+                                      sizeof(msm_dp_sdp->pb));
+       if (len < 0) {
+               DRM_ERROR("unable to pack sdp header\n");
+               return len;
+       }
+
+       return len;
+}
diff --git a/drivers/gpu/drm/msm/dp/dp_utils.h b/drivers/gpu/drm/msm/dp/dp_utils.h
index 5a505cbf3432b..6946bc51cae97 100644
--- a/drivers/gpu/drm/msm/dp/dp_utils.h
+++ b/drivers/gpu/drm/msm/dp/dp_utils.h
@@ -6,6 +6,8 @@
  #ifndef _DP_UTILS_H_
  #define _DP_UTILS_H_

+#include <drm/display/drm_dp_helper.h>
+
  #define HEADER_BYTE_0_BIT       0
  #define PARITY_BYTE_0_BIT       8
  #define HEADER_BYTE_1_BIT      16
@@ -15,8 +17,24 @@
  #define HEADER_BYTE_3_BIT      16
  #define PARITY_BYTE_3_BIT      24

+struct msm_dp_vsc_sdp_parity {
+       u8 PB0;
+       u8 PB1;
+       u8 PB2;
+       u8 PB3;
+} __packed;
+
+struct msm_dp_sdp_with_parity {
+       struct dp_sdp vsc_sdp;
+       struct msm_dp_vsc_sdp_parity pb;
+};
+
  u8 dp_utils_get_g0_value(u8 data);
  u8 dp_utils_get_g1_value(u8 data);
  u8 dp_utils_calculate_parity(u32 data);
+ssize_t dp_utils_pack_sdp_header(struct dp_sdp_header *sdp_header, struct msm_dp_vsc_sdp_parity *pb,
+                                size_t size);
+ssize_t dp_utils_pack_vsc_sdp(struct drm_dp_vsc_sdp *vsc,
+                             struct msm_dp_sdp_with_parity *msm_dp_sdp);

  #endif /* _DP_UTILS_H_ */
--
2.39.2









