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>

Author: Paloma Arellano

drivers/gpu/drm/msm/dp/dp_catalog.c

@@ -892,6 +892,99 @@ 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 dp_sdp *vsc_sdp)
+{
+	struct dp_catalog_private *catalog;
+	u32 header[2];
+	u32 val;
+	int i;
+
+	catalog = container_of(dp_catalog, struct dp_catalog_private, dp_catalog);
+
+	dp_utils_pack_sdp_header(&vsc_sdp->sdp_header, header);
+
+	dp_write_link(catalog, MMSS_DP_GENERIC0_0, header[0]);
+	dp_write_link(catalog, MMSS_DP_GENERIC0_1, header[1]);
+
+	for (i = 0; i < sizeof(vsc_sdp->db); i += 4) {
+		val = ((vsc_sdp->db[i]) | (vsc_sdp->db[i + 1] << 8) | (vsc_sdp->db[i + 2] << 16) |
+		       (vsc_sdp->db[i + 3] << 24));
+		dp_write_link(catalog, MMSS_DP_GENERIC0_2 + i, val);
+	}
+}
+
+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 dp_sdp *vsc_sdp)
+{
+	struct dp_catalog_private *catalog;
+	u32 cfg, cfg2, misc;
+
+	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, vsc_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;
+
+	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)
 {

drivers/gpu/drm/msm/dp/dp_catalog.h

@@ -8,6 +8,7 @@
 
 #include <drm/drm_modes.h>
 
+#include "dp_utils.h"
 #include "disp/msm_disp_snapshot.h"
 
 /* interrupts */
@@ -29,6 +30,9 @@
 
 #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,
@@ -120,6 +124,8 @@ 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 dp_sdp *vsc_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);

drivers/gpu/drm/msm/dp/dp_ctrl.c

@@ -2048,6 +2048,8 @@ void dp_ctrl_off_link_stream(struct dp_ctrl *dp_ctrl)
 	ctrl = container_of(dp_ctrl, struct dp_ctrl_private, dp_ctrl);
 	phy = ctrl->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);
 
@@ -2100,6 +2102,8 @@ void dp_ctrl_off(struct dp_ctrl *dp_ctrl)
 	ctrl = container_of(dp_ctrl, struct dp_ctrl_private, dp_ctrl);
 	phy = ctrl->phy;
 
+	dp_catalog_panel_disable_vsc_sdp(ctrl->catalog);
+
 	dp_catalog_ctrl_mainlink_ctrl(ctrl->catalog, false);
 
 	dp_catalog_ctrl_reset(ctrl->catalog);

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>
@@ -288,6 +289,53 @@ 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 dp_sdp vsc_sdp;
+	ssize_t len;
+
+	if (!dp_panel) {
+		DRM_ERROR("invalid input\n");
+		return -EINVAL;
+	}
+
+	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;
+
+	len = drm_dp_vsc_sdp_pack(&vsc_sdp_data, &vsc_sdp);
+	if (len < 0) {
+		DRM_ERROR("unable to pack vsc sdp\n");
+		return len;
+	}
+
+	dp_catalog_panel_enable_vsc_sdp(catalog, &vsc_sdp);
+
+	return 0;
+}
+
 void dp_panel_dump_regs(struct dp_panel *dp_panel)
 {
 	struct dp_catalog *catalog;
@@ -351,6 +399,10 @@ 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;

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 DP_MISC0_COLORIMERY_CFG_LEGACY_RGB	(0)
 #define DP_MISC0_COLORIMERY_CFG_CEA_RGB		(0x04)
@@ -204,9 +205,11 @@
 #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)

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;
+}

drivers/gpu/drm/msm/dp/dp_utils.h

@@ -6,6 +6,10 @@
 #ifndef _DP_UTILS_H_
 #define _DP_UTILS_H_
 
+#include <linux/bitfield.h>
+#include <linux/bits.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 +19,18 @@
 #define HEADER_BYTE_3_BIT	16
 #define PARITY_BYTE_3_BIT	24
 
+#define HEADER_0_MASK	    GENMASK(7, 0)
+#define PARITY_0_MASK	    GENMASK(15, 8)
+#define HEADER_1_MASK	    GENMASK(23, 16)
+#define PARITY_1_MASK	    GENMASK(31, 24)
+#define HEADER_2_MASK	    GENMASK(7, 0)
+#define PARITY_2_MASK	    GENMASK(15, 8)
+#define HEADER_3_MASK	    GENMASK(23, 16)
+#define PARITY_3_MASK	    GENMASK(31, 24)
+
 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, u32 *header_buff);
 
 #endif /* _DP_UTILS_H_ */