drm/i915: Parse DSI backlight/cabc ports.

This patch parse DSI backlight/cabc ports info from
VBT and save them inside local structure. This saved info
can be directly used while initializing DSI for different
platforms instead of parsing for each platform.

V2: Changes:
    - Typo fix in commit message.
    - Move up newly added port variables (Jani N)
    - Remove redundant initialization (Jani N)
    - Don't parse CABC ports if not supported (Jani N)
V3: Patch restructure (Suggested by Jani N)

Credits-to: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1507898700-20016-1-git-send-email-madhav.chauhan@intel.com

drivers/gpu/drm/i915/i915_drv.h

@@ -1778,6 +1778,8 @@ struct intel_vbt_data {
 		u16 panel_id;
 		struct mipi_config *config;
 		struct mipi_pps_data *pps;
+		u16 bl_ports;
+		u16 cabc_ports;
 		u8 seq_version;
 		u32 size;
 		u8 *data;

drivers/gpu/drm/i915/intel_bios.c

@@ -691,6 +691,50 @@ parse_psr(struct drm_i915_private *dev_priv, const struct bdb_header *bdb)
 	dev_priv->vbt.psr.tp2_tp3_wakeup_time = psr_table->tp2_tp3_wakeup_time;
 }
 
+static void parse_dsi_backlight_ports(struct drm_i915_private *dev_priv,
+				      u16 version, enum port port)
+{
+	if (!dev_priv->vbt.dsi.config->dual_link || version < 197) {
+		dev_priv->vbt.dsi.bl_ports = BIT(port);
+		if (dev_priv->vbt.dsi.config->cabc_supported)
+			dev_priv->vbt.dsi.cabc_ports = BIT(port);
+
+		dev_priv->vbt.dsi.config->dl_dcs_cabc_ports = 0;
+		dev_priv->vbt.dsi.config->dl_dcs_backlight_ports = 0;
+		return;
+	}
+
+	switch (dev_priv->vbt.dsi.config->dl_dcs_backlight_ports) {
+	case DL_DCS_PORT_A:
+		dev_priv->vbt.dsi.bl_ports = BIT(PORT_A);
+		break;
+	case DL_DCS_PORT_C:
+		dev_priv->vbt.dsi.bl_ports = BIT(PORT_C);
+		break;
+	default:
+	case DL_DCS_PORT_A_AND_C:
+		dev_priv->vbt.dsi.bl_ports = BIT(PORT_A) | BIT(PORT_C);
+		break;
+	}
+
+	if (!dev_priv->vbt.dsi.config->cabc_supported)
+		return;
+
+	switch (dev_priv->vbt.dsi.config->dl_dcs_cabc_ports) {
+	case DL_DCS_PORT_A:
+		dev_priv->vbt.dsi.cabc_ports = BIT(PORT_A);
+		break;
+	case DL_DCS_PORT_C:
+		dev_priv->vbt.dsi.cabc_ports = BIT(PORT_C);
+		break;
+	default:
+	case DL_DCS_PORT_A_AND_C:
+		dev_priv->vbt.dsi.cabc_ports =
+					BIT(PORT_A) | BIT(PORT_C);
+		break;
+	}
+}
+
 static void
 parse_mipi_config(struct drm_i915_private *dev_priv,
 		  const struct bdb_header *bdb)
@@ -699,9 +743,10 @@ parse_mipi_config(struct drm_i915_private *dev_priv,
 	const struct mipi_config *config;
 	const struct mipi_pps_data *pps;
 	int panel_type = dev_priv->vbt.panel_type;
+	enum port port;
 
 	/* parse MIPI blocks only if LFP type is MIPI */
-	if (!intel_bios_is_dsi_present(dev_priv, NULL))
+	if (!intel_bios_is_dsi_present(dev_priv, &port))
 		return;
 
 	/* Initialize this to undefined indicating no generic MIPI support */
@@ -742,15 +787,7 @@ parse_mipi_config(struct drm_i915_private *dev_priv,
 		return;
 	}
 
-	/*
-	 * These fields are introduced from the VBT version 197 onwards,
-	 * so making sure that these bits are set zero in the previous
-	 * versions.
-	 */
-	if (dev_priv->vbt.dsi.config->dual_link && bdb->version < 197) {
-		dev_priv->vbt.dsi.config->dl_dcs_cabc_ports = 0;
-		dev_priv->vbt.dsi.config->dl_dcs_backlight_ports = 0;
-	}
+	parse_dsi_backlight_ports(dev_priv, bdb->version, port);
 
 	/* We have mandatory mipi config blocks. Initialize as generic panel */
 	dev_priv->vbt.dsi.panel_id = MIPI_DSI_GENERIC_PANEL_ID;