drm/i915: Parse the MIPI related VBT Block and store relevant info

Initial parsing of the VBT MIPI block. For now, just store the panel id
if found.

Note: Again there seems to be no documentation for this piece of lore.
The doc situation for byt+ is just a bad joke :(
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -1065,6 +1065,11 @@ struct intel_vbt_data {
 	int edp_bpp;
 	struct edp_power_seq edp_pps;
 
+	/* MIPI DSI */
+	struct {
+		u16 panel_id;
+	} dsi;
+
 	int crt_ddc_pin;
 
 	int child_dev_num;

drivers/gpu/drm/i915/intel_bios.c

@@ -568,6 +568,21 @@ parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
 	}
 }
 
+static void
+parse_mipi(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
+{
+	struct bdb_mipi *mipi;
+
+	mipi = find_section(bdb, BDB_MIPI);
+	if (!mipi) {
+		DRM_DEBUG_KMS("No MIPI BDB found");
+		return;
+	}
+
+	/* XXX: add more info */
+	dev_priv->vbt.dsi.panel_id = mipi->panel_id;
+}
+
 static void
 parse_device_mapping(struct drm_i915_private *dev_priv,
 		       struct bdb_header *bdb)
@@ -745,6 +760,7 @@ intel_parse_bios(struct drm_device *dev)
 	parse_device_mapping(dev_priv, bdb);
 	parse_driver_features(dev_priv, bdb);
 	parse_edp(dev_priv, bdb);
+	parse_mipi(dev_priv, bdb);
 
 	if (bios)
 		pci_unmap_rom(pdev, bios);

drivers/gpu/drm/i915/intel_bios.h

@@ -104,6 +104,7 @@ struct vbios_data {
 #define BDB_LVDS_LFP_DATA	 42
 #define BDB_LVDS_BACKLIGHT	 43
 #define BDB_LVDS_POWER		 44
+#define BDB_MIPI		 50
 #define BDB_SKIP		254 /* VBIOS private block, ignore */
 
 struct bdb_general_features {
@@ -618,4 +619,44 @@ int intel_parse_bios(struct drm_device *dev);
 #define		PORT_IDPC	8
 #define		PORT_IDPD	9
 
+/* MIPI DSI panel info */
+struct bdb_mipi {
+	u16 panel_id;
+	u16 bridge_revision;
+
+	/* General params */
+	u32 dithering:1;
+	u32 bpp_pixel_format:1;
+	u32 rsvd1:1;
+	u32 dphy_valid:1;
+	u32 resvd2:28;
+
+	u16 port_info;
+	u16 rsvd3:2;
+	u16 num_lanes:2;
+	u16 rsvd4:12;
+
+	/* DSI config */
+	u16 virt_ch_num:2;
+	u16 vtm:2;
+	u16 rsvd5:12;
+
+	u32 dsi_clock;
+	u32 bridge_ref_clk;
+	u16 rsvd_pwr;
+
+	/* Dphy Params */
+	u32 prepare_cnt:5;
+	u32 rsvd6:3;
+	u32 clk_zero_cnt:8;
+	u32 trail_cnt:5;
+	u32 rsvd7:3;
+	u32 exit_zero_cnt:6;
+	u32 rsvd8:2;
+
+	u32 hl_switch_cnt;
+	u32 lp_byte_clk;
+	u32 clk_lane_switch_cnt;
+} __attribute__((packed));
+
 #endif /* _I830_BIOS_H_ */