drm/i915: parse eDP panel color depth from VBT block

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/i915_drv.h

@@ -283,6 +283,7 @@ typedef struct drm_i915_private {
 	unsigned int lvds_use_ssc:1;
 	unsigned int edp_support:1;
 	int lvds_ssc_freq;
+	int edp_bpp;
 
 	struct notifier_block lid_notifier;
 

drivers/gpu/drm/i915/intel_bios.c

@@ -33,6 +33,8 @@
 #define	SLAVE_ADDR1	0x70
 #define	SLAVE_ADDR2	0x72
 
+static int panel_type;
+
 static void *
 find_section(struct bdb_header *bdb, int section_id)
 {
@@ -128,6 +130,7 @@ parse_lfp_panel_data(struct drm_i915_private *dev_priv,
 	dev_priv->lvds_dither = lvds_options->pixel_dither;
 	if (lvds_options->panel_type == 0xff)
 		return;
+	panel_type = lvds_options->panel_type;
 
 	lvds_lfp_data = find_section(bdb, BDB_LVDS_LFP_DATA);
 	if (!lvds_lfp_data)
@@ -405,6 +408,34 @@ parse_driver_features(struct drm_i915_private *dev_priv,
 		dev_priv->render_reclock_avail = true;
 }
 
+static void
+parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
+{
+	struct bdb_edp *edp;
+
+	edp = find_section(bdb, BDB_EDP);
+	if (!edp) {
+		if (SUPPORTS_EDP(dev_priv->dev) && dev_priv->edp_support) {
+			DRM_DEBUG_KMS("No eDP BDB found but eDP panel supported,\
+				       assume 18bpp panel color depth.\n");
+			dev_priv->edp_bpp = 18;
+		}
+		return;
+	}
+
+	switch ((edp->color_depth >> (panel_type * 2)) & 3) {
+	case EDP_18BPP:
+		dev_priv->edp_bpp = 18;
+		break;
+	case EDP_24BPP:
+		dev_priv->edp_bpp = 24;
+		break;
+	case EDP_30BPP:
+		dev_priv->edp_bpp = 30;
+		break;
+	}
+}
+
 static void
 parse_device_mapping(struct drm_i915_private *dev_priv,
 		       struct bdb_header *bdb)
@@ -522,6 +553,7 @@ intel_init_bios(struct drm_device *dev)
 	parse_sdvo_device_mapping(dev_priv, bdb);
 	parse_device_mapping(dev_priv, bdb);
 	parse_driver_features(dev_priv, bdb);
+	parse_edp(dev_priv, bdb);
 
 	pci_unmap_rom(pdev, bios);
 

drivers/gpu/drm/i915/intel_bios.h

@@ -98,6 +98,7 @@ struct vbios_data {
 #define BDB_SDVO_LVDS_PNP_IDS	 24
 #define BDB_SDVO_LVDS_POWER_SEQ	 25
 #define BDB_TV_OPTIONS		 26
+#define BDB_EDP			 27
 #define BDB_LVDS_OPTIONS	 40
 #define BDB_LVDS_LFP_DATA_PTRS	 41
 #define BDB_LVDS_LFP_DATA	 42
@@ -426,6 +427,45 @@ struct bdb_driver_features {
 	u8 custom_vbt_version;
 } __attribute__((packed));
 
+#define EDP_18BPP	0
+#define EDP_24BPP	1
+#define EDP_30BPP	2
+#define EDP_RATE_1_62	0
+#define EDP_RATE_2_7	1
+#define EDP_LANE_1	0
+#define EDP_LANE_2	1
+#define EDP_LANE_4	3
+#define EDP_PREEMPHASIS_NONE	0
+#define EDP_PREEMPHASIS_3_5dB	1
+#define EDP_PREEMPHASIS_6dB	2
+#define EDP_PREEMPHASIS_9_5dB	3
+#define EDP_VSWING_0_4V		0
+#define EDP_VSWING_0_6V		1
+#define EDP_VSWING_0_8V		2
+#define EDP_VSWING_1_2V		3
+
+struct edp_power_seq {
+	u16 t3;
+	u16 t7;
+	u16 t9;
+	u16 t10;
+	u16 t12;
+} __attribute__ ((packed));
+
+struct edp_link_params {
+	u8 rate:4;
+	u8 lanes:4;
+	u8 preemphasis:4;
+	u8 vswing:4;
+} __attribute__ ((packed));
+
+struct bdb_edp {
+	struct edp_power_seq power_seqs[16];
+	u32 color_depth;
+	u32 sdrrs_msa_timing_delay;
+	struct edp_link_params link_params[16];
+} __attribute__ ((packed));
+
 bool intel_init_bios(struct drm_device *dev);
 
 /*