drm/i915: parse child device from VBT

On some laptops there is no HDMI/DP. But the xrandr still reports
several disconnected HDMI/display ports. In such case the user will be
confused.
 >DVI1 disconnected (normal left inverted right x axis y axis)
 >DP1 disconnected (normal left inverted right x axis y axis)
 >DVI2 disconnected (normal left inverted right x axis y axis)
 >DP2 disconnected (normal left inverted right x axis y axis)
 >DP3 disconnected (normal left inverted right x axis y axis)

This patch set is to use the child device parsed in VBT to decide whether
the HDMI/DP/LVDS/TV should be initialized.

Parse the child device from VBT.

The device class type is also added for LFP, TV, HDMI, DP output.

https://bugs.freedesktop.org/show_bug.cgi?id=22785

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 65 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 800d13bd9e6..73ceb36c790 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -404,6 +404,70 @@ parse_driver_features(struct drm_i915_private *dev_priv,
 		dev_priv->render_reclock_avail = true;
 }
 
+static void
+parse_device_mapping(struct drm_i915_private *dev_priv,
+		       struct bdb_header *bdb)
+{
+	struct bdb_general_definitions *p_defs;
+	struct child_device_config *p_child, *child_dev_ptr;
+	int i, child_device_num, count;
+	u16	block_size;
+
+	p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
+	if (!p_defs) {
+		DRM_DEBUG_KMS("No general definition block is found\n");
+		return;
+	}
+	/* judge whether the size of child device meets the requirements.
+	 * If the child device size obtained from general definition block
+	 * is different with sizeof(struct child_device_config), skip the
+	 * parsing of sdvo device info
+	 */
+	if (p_defs->child_dev_size != sizeof(*p_child)) {
+		/* different child dev size . Ignore it */
+		DRM_DEBUG_KMS("different child size is found. Invalid.\n");
+		return;
+	}
+	/* get the block size of general definitions */
+	block_size = get_blocksize(p_defs);
+	/* get the number of child device */
+	child_device_num = (block_size - sizeof(*p_defs)) /
+				sizeof(*p_child);
+	count = 0;
+	/* get the number of child device that is present */
+	for (i = 0; i < child_device_num; i++) {
+		p_child = &(p_defs->devices[i]);
+		if (!p_child->device_type) {
+			/* skip the device block if device type is invalid */
+			continue;
+		}
+		count++;
+	}
+	if (!count) {
+		DRM_DEBUG_KMS("no child dev is parsed from VBT \n");
+		return;
+	}
+	dev_priv->child_dev = kzalloc(sizeof(*p_child) * count, GFP_KERNEL);
+	if (!dev_priv->child_dev) {
+		DRM_DEBUG_KMS("No memory space for child device\n");
+		return;
+	}
+
+	dev_priv->child_dev_num = count;
+	count = 0;
+	for (i = 0; i < child_device_num; i++) {
+		p_child = &(p_defs->devices[i]);
+		if (!p_child->device_type) {
+			/* skip the device block if device type is invalid */
+			continue;
+		}
+		child_dev_ptr = dev_priv->child_dev + count;
+		count++;
+		memcpy((void *)child_dev_ptr, (void *)p_child,
+					sizeof(*p_child));
+	}
+	return;
+}
 /**
  * intel_init_bios - initialize VBIOS settings & find VBT
  * @dev: DRM device
@@ -455,6 +519,7 @@ intel_init_bios(struct drm_device *dev)
 	parse_lfp_panel_data(dev_priv, bdb);
 	parse_sdvo_panel_data(dev_priv, bdb);
 	parse_sdvo_device_mapping(dev_priv, bdb);
+	parse_device_mapping(dev_priv, bdb);
 	parse_driver_features(dev_priv, bdb);
 
 	pci_unmap_rom(pdev, bios);