drm/i915: Detect if MIPI panel based on VBT and initialize only if present

It seems by default the VBT has MIPI configuration block as well. The
Generic driver will assume always MIPI if MIPI configuration block is found.
This is causing probelm when actually there is eDP. Fix this by looking
into general definition block which will have device configurations. From here
we can figure out what is the LFP type and initialize MIPI only if MIPI
is found.

v2: Addressed review comments by Damien
    - Moved PORT definitions to intel_bios.h and renamed as DVO_PORT_MIPIA
    - renamed is_mipi to has_mipi and moved definition as suggested
    - Check has_mipi inside parse_mipi and intel_dsi_init insted of outside

v3: Make has_mipi as a bitfield as suggested

Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
[danvet: fold in conditions to pack everything neatly below 80 chars.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -1222,6 +1222,7 @@ struct intel_vbt_data {
 	unsigned int lvds_use_ssc:1;
 	unsigned int display_clock_mode:1;
 	unsigned int fdi_rx_polarity_inverted:1;
+	unsigned int has_mipi:1;
 	int lvds_ssc_freq;
 	unsigned int bios_lvds_val; /* initial [PCH_]LVDS reg val in VBIOS */
 
@@ -1245,6 +1246,7 @@ struct intel_vbt_data {
 
 	/* MIPI DSI */
 	struct {
+		u16 port;
 		u16 panel_id;
 		struct mipi_config *config;
 		struct mipi_pps_data *pps;

drivers/gpu/drm/i915/intel_bios.c

@@ -720,6 +720,10 @@ parse_mipi(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
 	int i, panel_id, seq_size;
 	u16 block_size;
 
+	/* parse MIPI blocks only if LFP type is MIPI */
+	if (!dev_priv->vbt.has_mipi)
+		return;
+
 	/* Initialize this to undefined indicating no generic MIPI support */
 	dev_priv->vbt.dsi.panel_id = MIPI_DSI_UNDEFINED_PANEL_ID;
 
@@ -1035,6 +1039,15 @@ parse_device_mapping(struct drm_i915_private *dev_priv,
 			/* skip the device block if device type is invalid */
 			continue;
 		}
+
+		if (p_child->common.dvo_port >= DVO_PORT_MIPIA
+		    && p_child->common.dvo_port <= DVO_PORT_MIPID
+		    &&p_child->common.device_type & DEVICE_TYPE_MIPI_OUTPUT) {
+			DRM_DEBUG_KMS("Found MIPI as LFP\n");
+			dev_priv->vbt.has_mipi = 1;
+			dev_priv->vbt.dsi.port = p_child->common.dvo_port;
+		}
+
 		child_dev_ptr = dev_priv->vbt.child_dev + count;
 		count++;
 		memcpy((void *)child_dev_ptr, (void *)p_child,

drivers/gpu/drm/i915/intel_bios.h

@@ -743,6 +743,10 @@ int intel_parse_bios(struct drm_device *dev);
 #define DVO_PORT_DPC	8
 #define DVO_PORT_DPD	9
 #define DVO_PORT_DPA	10
+#define DVO_PORT_MIPIA	21
+#define DVO_PORT_MIPIB	22
+#define DVO_PORT_MIPIC	23
+#define DVO_PORT_MIPID	24
 
 /* Block 52 contains MIPI Panel info
  * 6 such enteries will there. Index into correct

drivers/gpu/drm/i915/intel_dsi.c

@@ -660,6 +660,10 @@ bool intel_dsi_init(struct drm_device *dev)
 
 	DRM_DEBUG_KMS("\n");
 
+	/* There is no detection method for MIPI so rely on VBT */
+	if (!dev_priv->vbt.has_mipi)
+		return false;
+
 	intel_dsi = kzalloc(sizeof(*intel_dsi), GFP_KERNEL);
 	if (!intel_dsi)
 		return false;