drm/edid: add displayid detailed 1 timings to the modelist.drm-displayid-timings

The tiled 5K Dell monitor appears to be hiding it's tiled mode
inside the displayid timings block, this patch parses this
blocks and adds the modes to the modelist.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95207
Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 122 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index e85d82898499..aca9e25ea713 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3925,6 +3925,110 @@ static int validate_displayid(u8 *displayid, int length, int idx)
 	return 0;
 }
 
+static struct drm_display_mode *drm_mode_displayid_detailed(struct drm_device *dev,
+							    struct displayid_detailed_timings_1 *timings)
+{
+	struct drm_display_mode *mode;
+	unsigned pixel_clock = (timings->pixel_clock[0] |
+				(timings->pixel_clock[1] << 8) |
+				(timings->pixel_clock[2] << 16));
+	unsigned hactive = (timings->hactive[0] | timings->hactive[1] << 8) + 1;
+	unsigned hblank = (timings->hblank[0] | timings->hblank[1] << 8) + 1;
+	unsigned hsync = (timings->hsync[0] | (timings->hsync[1] & 0x7f) << 8) + 1;
+	unsigned hsync_width = (timings->hsw[0] | timings->hsw[1] << 8) + 1;
+	unsigned vactive = (timings->vactive[0] | timings->vactive[1] << 8) + 1;
+	unsigned vblank = (timings->vblank[0] | timings->vblank[1] << 8) + 1;
+	unsigned vsync = (timings->vsync[0] | (timings->vsync[1] & 0x7f) << 8) + 1;
+	unsigned vsync_width = (timings->vsw[0] | timings->vsw[1] << 8) + 1;
+	bool hsync_positive = (timings->hsync[1] >> 7) & 0x1;
+	bool vsync_positive = (timings->vsync[1] >> 7) & 0x1;
+	mode = drm_mode_create(dev);
+	if (!mode)
+		return NULL;
+
+	mode->clock = pixel_clock * 10;
+	mode->hdisplay = hactive;
+	mode->hsync_start = mode->hdisplay + hsync;
+	mode->hsync_end = mode->hsync_start + hsync_width;
+	mode->htotal = mode->hdisplay + hblank;
+
+	mode->vdisplay = vactive;
+	mode->vsync_start = mode->vdisplay + vsync;
+	mode->vsync_end = mode->vsync_start + vsync_width;
+	mode->vtotal = mode->vdisplay + vblank;
+
+	mode->flags = 0;
+	mode->flags |= hsync_positive ? DRM_MODE_FLAG_PHSYNC : DRM_MODE_FLAG_NHSYNC;
+	mode->flags |= vsync_positive ? DRM_MODE_FLAG_PVSYNC : DRM_MODE_FLAG_NVSYNC;
+	mode->type = DRM_MODE_TYPE_DRIVER;
+
+	if (timings->flags & 0x80)
+		mode->type |= DRM_MODE_TYPE_PREFERRED;
+	mode->vrefresh = drm_mode_vrefresh(mode);
+	drm_mode_set_name(mode);
+
+	return mode;
+}
+
+static int add_displayid_detailed_1_modes(struct drm_connector *connector,
+					  struct displayid_block *block)
+{
+	struct displayid_detailed_timing_block *det = (struct displayid_detailed_timing_block *)block;
+	int i;
+	int num_timings;
+	struct drm_display_mode *newmode;
+	int num_modes = 0;
+	/* blocks must be multiple of 20 bytes length */
+	if (block->num_bytes % 20)
+		return 0;
+
+	num_timings = block->num_bytes / 20;
+	for (i = 0; i < num_timings; i++) {
+		struct displayid_detailed_timings_1 *timings = &det->timings[i];
+
+		newmode = drm_mode_displayid_detailed(connector->dev, timings);
+		if (!newmode)
+			continue;
+
+		drm_mode_probed_add(connector, newmode);
+		num_modes++;
+	}
+	return num_modes;
+}
+
+static int add_displayid_detailed_modes(struct drm_connector *connector,
+					struct edid *edid)
+{
+	u8 *displayid;
+	int ret;
+	int idx = 1;
+	int length = EDID_LENGTH;
+	struct displayid_block *block;
+	int num_modes = 0;
+
+	displayid = drm_find_displayid_extension(edid);
+	if (!displayid)
+		return 0;
+
+	ret = validate_displayid(displayid, length, idx);
+	if (ret)
+		return 0;
+
+	idx += sizeof(struct displayid_hdr);
+	while (block = (struct displayid_block *)&displayid[idx],
+	       idx + sizeof(struct displayid_block) <= length &&
+	       idx + sizeof(struct displayid_block) + block->num_bytes <= length &&
+	       block->num_bytes > 0) {
+		idx += block->num_bytes + sizeof(struct displayid_block);
+		switch (block->tag) {
+		case DATA_BLOCK_TYPE_1_DETAILED_TIMING:
+			num_modes += add_displayid_detailed_1_modes(connector, block);
+			break;
+		}
+	}
+	return num_modes;
+}
+
 /**
  * drm_add_edid_modes - add modes from EDID data, if available
  * @connector: connector we're probing
@@ -3970,6 +4074,7 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
 	num_modes += add_established_modes(connector, edid);
 	num_modes += add_cea_modes(connector, edid);
 	num_modes += add_alternate_cea_modes(connector, edid);
+	num_modes += add_displayid_detailed_modes(connector, edid);
 	if (edid->features & DRM_EDID_FEATURE_DEFAULT_GTF)
 		num_modes += add_inferred_modes(connector, edid);
 
diff --git a/include/drm/drm_displayid.h b/include/drm/drm_displayid.h
index 042f9fcc82ca..edef51d66937 100644
--- a/include/drm/drm_displayid.h
+++ b/include/drm/drm_displayid.h
@@ -75,4 +75,21 @@ struct displayid_tiled_block {
 	u8 topology_id[8];
 } __packed;
 
+struct displayid_detailed_timings_1 {
+	u8 pixel_clock[3];
+	u8 flags;
+	u8 hactive[2];
+	u8 hblank[2];
+	u8 hsync[2];
+	u8 hsw[2];
+	u8 vactive[2];
+	u8 vblank[2];
+	u8 vsync[2];
+	u8 vsw[2];
+};
+
+struct displayid_detailed_timing_block {
+	struct displayid_block base;
+	struct displayid_detailed_timings_1 timings[0];
+};
 #endif