drm/msm/dp: add VSC SDP support for YUV420 over DP

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 v5:
	- Slightly modify use of drm_dp_vsc_sdp_pack()
	- Remove dp_catalog NULL checks
	- Modify dp_utils_pack_sdp_header() to more clearly pack the
	  header buffer
	- Move dp_utils_pack_sdp_header() inside of
	  dp_catalog_panel_send_vsc_sdp to clearly show the relationship
	  between the header buffer and the vsc_sdp struct
	- Due to the last point, remove the dp_utils_pack_vsc_sdp()
	  function and only call drm_dp_vsc_sdp_pack() in
	  dp_panel_setup_vsc_sdp_yuv_420()

Changes in v4:
	- Remove struct msm_dp_sdp_with_parity
	- Use dp_utils_pack_sdp_header() to pack the SDP header and
	  parity bytes into a buffer
	- Use this buffer when writing the VSC SDP data in
	  dp_catalog_panel_send_vsc_sdp()
	- Write to all of the MMSS_DP_GENERIC0 registers instead of just
	  the ones with non-zero values

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@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/579636/
Link: https://lore.kernel.org/r/20240222194025.25329-14-quic_parellan@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/gpu/drm/msm/dp/dp_utils.c b/drivers/gpu/drm/msm/dp/dp_utils.c
index 3a44fe738c00..da9207caf72d 100644
--- a/drivers/gpu/drm/msm/dp/dp_utils.c
+++ b/drivers/gpu/drm/msm/dp/dp_utils.c
@@ -7,6 +7,8 @@
 
 #include "dp_utils.h"
 
+#define DP_SDP_HEADER_SIZE		8
+
 u8 dp_utils_get_g0_value(u8 data)
 {
 	u8 c[4];
@@ -71,3 +73,24 @@ u8 dp_utils_calculate_parity(u32 data)
 
 	return parity_byte;
 }
+
+ssize_t dp_utils_pack_sdp_header(struct dp_sdp_header *sdp_header, u32 *header_buff)
+{
+	size_t length;
+
+	length = sizeof(header_buff);
+	if (length < DP_SDP_HEADER_SIZE)
+		return -ENOSPC;
+
+	header_buff[0] = FIELD_PREP(HEADER_0_MASK, sdp_header->HB0) |
+		FIELD_PREP(PARITY_0_MASK, dp_utils_calculate_parity(sdp_header->HB0)) |
+		FIELD_PREP(HEADER_1_MASK, sdp_header->HB1) |
+		FIELD_PREP(PARITY_1_MASK, dp_utils_calculate_parity(sdp_header->HB1));
+
+	header_buff[1] = FIELD_PREP(HEADER_2_MASK, sdp_header->HB2) |
+		FIELD_PREP(PARITY_2_MASK, dp_utils_calculate_parity(sdp_header->HB2)) |
+		FIELD_PREP(HEADER_3_MASK, sdp_header->HB3) |
+		FIELD_PREP(PARITY_3_MASK, dp_utils_calculate_parity(sdp_header->HB3));
+
+	return length;
+}