drm/i915: parse VBT general definition block to get the SDVO device info

The general definition block contains the child device tables, which include
the SDVO device info. For example: device slave address, device dvo port,
device type.

We will get the info of SDVO device by parsing the general definition blocks.
Only when a valid slave address is found, it is regarded as the SDVO device.
And the info of DVO port and slave address is recorded.

http://bugs.freedesktop.org/show_bug.cgi?id=20429

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

2 files changed, 93 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ded9e786883e..db81f5513daa 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -126,6 +126,13 @@ struct drm_i915_fence_reg {
         struct drm_gem_object *obj;
 };
 
+struct sdvo_device_mapping {
+        u8 dvo_port;
+        u8 slave_addr;
+        u8 dvo_wiring;
+        u8 initialized;
+};
+
 typedef struct drm_i915_private {
         struct drm_device *dev;
 
@@ -389,6 +396,7 @@ typedef struct drm_i915_private {
                 /* storage for physical objects */
                 struct drm_i915_gem_phys_object *phys_objs[I915_MAX_PHYS_OBJECT];
         } mm;
+        struct sdvo_device_mapping sdvo_mappings[2];
 } drm_i915_private_t;
 
 /** driver private structure attached to each drm_gem_object */
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 9d78cff33b24..754dd22fdd77 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -30,6 +30,8 @@
 #include "i915_drv.h"
 #include "intel_bios.h"
 
+#define SLAVE_ADDR1     0x70
+#define SLAVE_ADDR2     0x72
 
 static void *
 find_section(struct bdb_header *bdb, int section_id)
@@ -193,6 +195,88 @@ parse_general_features(struct drm_i915_private *dev_priv,
         }
 }
 
+static void
+parse_sdvo_device_mapping(struct drm_i915_private *dev_priv,
+                       struct bdb_header *bdb)
+{
+        struct sdvo_device_mapping *p_mapping;
+        struct bdb_general_definitions *p_defs;
+        struct child_device_config *p_child;
+        int i, child_device_num, count;
+        u16     block_size, *block_ptr;
+
+        p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
+        if (!p_defs) {
+                DRM_DEBUG("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("different child size is found. Invalid.\n");
+                return;
+        }
+        /* get the block size of general definitions */
+        block_ptr = (u16 *)((char *)p_defs - 2);
+        block_size = *block_ptr;
+        /* get the number of child device */
+        child_device_num = (block_size - sizeof(*p_defs)) /
+                                sizeof(*p_child);
+        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;
+                }
+                if (p_child->slave_addr != SLAVE_ADDR1 &&
+                        p_child->slave_addr != SLAVE_ADDR2) {
+                        /*
+                         * If the slave address is neither 0x70 nor 0x72,
+                         * it is not a SDVO device. Skip it.
+                         */
+                        continue;
+                }
+                if (p_child->dvo_port != DEVICE_PORT_DVOB &&
+                        p_child->dvo_port != DEVICE_PORT_DVOC) {
+                        /* skip the incorrect SDVO port */
+                        DRM_DEBUG("Incorrect SDVO port. Skip it \n");
+                        continue;
+                }
+                DRM_DEBUG("the SDVO device with slave addr %2x is found on "
+                                "%s port\n",
+                                p_child->slave_addr,
+                                (p_child->dvo_port == DEVICE_PORT_DVOB) ?
+                                        "SDVOB" : "SDVOC");
+                p_mapping = &(dev_priv->sdvo_mappings[p_child->dvo_port - 1]);
+                if (!p_mapping->initialized) {
+                        p_mapping->dvo_port = p_child->dvo_port;
+                        p_mapping->slave_addr = p_child->slave_addr;
+                        p_mapping->dvo_wiring = p_child->dvo_wiring;
+                        p_mapping->initialized = 1;
+                } else {
+                        DRM_DEBUG("Maybe one SDVO port is shared by "
+                                         "two SDVO device.\n");
+                }
+                if (p_child->slave2_addr) {
+                        /* Maybe this is a SDVO device with multiple inputs */
+                        /* And the mapping info is not added */
+                        DRM_DEBUG("there exists the slave2_addr. Maybe this "
+                                "is a SDVO device with multiple inputs.\n");
+                }
+                count++;
+        }
+
+        if (!count) {
+                /* No SDVO device info is found */
+                DRM_DEBUG("No SDVO device info is found in VBT\n");
+        }
+        return;
+}
 /**
  * intel_init_bios - initialize VBIOS settings & find VBT
  * @dev: DRM device
@@ -242,7 +326,7 @@ intel_init_bios(struct drm_device *dev)
         parse_general_features(dev_priv, bdb);
         parse_lfp_panel_data(dev_priv, bdb);
         parse_sdvo_panel_data(dev_priv, bdb);
-
+        parse_sdvo_device_mapping(dev_priv, bdb);
         pci_unmap_rom(pdev, bios);
 
         return 0;