3 files changed, 164 insertions, 3 deletions

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 0d1eaa9966e9..eb89327fb737 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -908,6 +908,11 @@ void drm_connector_cleanup(struct drm_connector *connector)
         struct drm_device *dev = connector->dev;
         struct drm_display_mode *mode, *t;
 
+        if (connector->tile_group) {
+                drm_mode_put_tile_group(dev, connector->tile_group);
+                connector->tile_group = NULL;
+        }
+
         list_for_each_entry_safe(mode, t, &connector->probed_modes, head)
                 drm_mode_remove(connector, mode);
 
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index a7b5a71856a7..72fd8820e186 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -34,6 +34,7 @@
 #include <linux/module.h>
 #include <drm/drmP.h>
 #include <drm/drm_edid.h>
+#include <drm/drm_displayid.h>
 
 #define version_greater(edid, maj, min) \
         (((edid)->version > (maj)) || \
@@ -1014,6 +1015,8 @@ module_param_named(edid_fixup, edid_fixup, int, 0400);
 MODULE_PARM_DESC(edid_fixup,
                  "Minimum number of valid EDID header bytes (0-8, default 6)");
 
+static void drm_get_displayid(struct drm_connector *connector,
+                              struct edid *edid);
 /**
  * drm_edid_block_valid - Sanity check the EDID block (base or extension)
  * @raw_edid: pointer to raw EDID block
@@ -1308,10 +1311,15 @@ EXPORT_SYMBOL(drm_probe_ddc);
 struct edid *drm_get_edid(struct drm_connector *connector,
                           struct i2c_adapter *adapter)
 {
+        struct edid *edid;
+
         if (!drm_probe_ddc(adapter))
                 return NULL;
 
-        return drm_do_get_edid(connector, drm_do_probe_ddc_edid, adapter);
+        edid = drm_do_get_edid(connector, drm_do_probe_ddc_edid, adapter);
+        if (edid)
+                drm_get_displayid(connector, edid);
+        return edid;
 }
 EXPORT_SYMBOL(drm_get_edid);
 
@@ -2406,7 +2414,7 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
 /*
  * Search EDID for CEA extension block.
  */
-static u8 *drm_find_cea_extension(struct edid *edid)
+static u8 *drm_find_edid_extension(struct edid *edid, int ext_id)
 {
         u8 *edid_ext = NULL;
         int i;
@@ -2418,7 +2426,7 @@ static u8 *drm_find_cea_extension(struct edid *edid)
         /* Find CEA extension */
         for (i = 0; i < edid->extensions; i++) {
                 edid_ext = (u8 *)edid + EDID_LENGTH * (i + 1);
-                if (edid_ext[0] == CEA_EXT)
+                if (edid_ext[0] == ext_id)
                         break;
         }
 
@@ -2428,6 +2436,16 @@ static u8 *drm_find_cea_extension(struct edid *edid)
         return edid_ext;
 }
 
+static u8 *drm_find_cea_extension(struct edid *edid)
+{
+        return drm_find_edid_extension(edid, CEA_EXT);
+}
+
+static u8 *drm_find_displayid_extension(struct edid *edid)
+{
+        return drm_find_edid_extension(edid, DISPLAYID_EXT);
+}
+
 /*
  * Calculate the alternate clock for the CEA mode
  * (60Hz vs. 59.94Hz etc.)
@@ -3888,3 +3906,123 @@ drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_vendor_infoframe *frame,
         return 0;
 }
 EXPORT_SYMBOL(drm_hdmi_vendor_infoframe_from_display_mode);
+
+static int drm_parse_display_id(struct drm_connector *connector,
+                                u8 *displayid, int length,
+                                bool is_edid_extension)
+{
+        /* if this is an EDID extension the first byte will be 0x70 */
+        int idx = 0;
+        struct displayid_hdr *base;
+        struct displayid_block *block;
+        u8 csum = 0;
+        int i;
+
+        if (is_edid_extension)
+                idx = 1;
+
+        base = (struct displayid_hdr *)&displayid[idx];
+
+        DRM_DEBUG_KMS("base revision 0x%x, length %d, %d %d\n",
+                      base->rev, base->bytes, base->prod_id, base->ext_count);
+
+        if (base->bytes + 5 > length - idx)
+                return -EINVAL;
+
+        for (i = idx; i <= base->bytes + 5; i++) {
+                csum += displayid[i];
+        }
+        if (csum) {
+                DRM_ERROR("DisplayID checksum invalid, remainder is %d\n", csum);
+                return -EINVAL;
+        }
+
+        block = (struct displayid_block *)&displayid[idx + 4];
+        DRM_DEBUG_KMS("block id %d, rev %d, len %d\n",
+                      block->tag, block->rev, block->num_bytes);
+
+        switch (block->tag) {
+        case DATA_BLOCK_TILED_DISPLAY: {
+                struct displayid_tiled_block *tile = (struct displayid_tiled_block *)block;
+
+                u16 w, h;
+                u8 tile_v_loc, tile_h_loc;
+                u8 num_v_tile, num_h_tile;
+                struct drm_tile_group *tg;
+
+                w = tile->tile_size[0] | tile->tile_size[1] << 8;
+                h = tile->tile_size[2] | tile->tile_size[3] << 8;
+
+                num_v_tile = (tile->topo[0] & 0xf) | (tile->topo[2] & 0x30);
+                num_h_tile = (tile->topo[0] >> 4) | ((tile->topo[2] >> 2) & 0x30);
+                tile_v_loc = (tile->topo[1] & 0xf) | ((tile->topo[2] & 0x3) << 4);
+                tile_h_loc = (tile->topo[1] >> 4) | (((tile->topo[2] >> 2) & 0x3) << 4);
+
+                connector->has_tile = true;
+                if (tile->tile_cap & 0x80)
+                        connector->tile_is_single_monitor = true;
+
+                connector->num_h_tile = num_h_tile + 1;
+                connector->num_v_tile = num_v_tile + 1;
+                connector->tile_h_loc = tile_h_loc;
+                connector->tile_v_loc = tile_v_loc;
+                connector->tile_h_size = w + 1;
+                connector->tile_v_size = h + 1;
+
+                DRM_DEBUG_KMS("tile cap 0x%x\n", tile->tile_cap);
+                DRM_DEBUG_KMS("tile_size %d x %d\n", w + 1, h + 1);
+                DRM_DEBUG_KMS("topo num tiles %dx%d, location %dx%d\n",
+                       num_h_tile + 1, num_v_tile + 1, tile_h_loc, tile_v_loc);
+                DRM_DEBUG_KMS("vend %c%c%c\n", tile->topology_id[0], tile->topology_id[1], tile->topology_id[2]);
+
+                tg = drm_mode_get_tile_group(connector->dev, tile->topology_id);
+                if (!tg) {
+                        tg = drm_mode_create_tile_group(connector->dev, tile->topology_id);
+                }
+                if (!tg)
+                        return -ENOMEM;
+
+                if (connector->tile_group != tg) {
+                        /* if we haven't got a pointer,
+                           take the reference, drop ref to old tile group */
+                        if (connector->tile_group) {
+                                drm_mode_put_tile_group(connector->dev, connector->tile_group);
+                        }
+                        connector->tile_group = tg;
+                } else
+                        /* if same tile group, then release the ref we just took. */
+                        drm_mode_put_tile_group(connector->dev, tg);
+        }
+                break;
+        default:
+                printk("unknown displayid tag %d\n", block->tag);
+                break;
+        }
+        return 0;
+}
+
+static void drm_get_displayid(struct drm_connector *connector,
+                              struct edid *edid)
+{
+        void *displayid = NULL;
+        int ret;
+        connector->has_tile = false;
+        displayid = drm_find_displayid_extension(edid);
+        if (!displayid) {
+                /* drop reference to any tile group we had */
+                goto out_drop_ref;
+        }
+
+        ret = drm_parse_display_id(connector, displayid, EDID_LENGTH, true);
+        if (ret < 0)
+                goto out_drop_ref;
+        if (!connector->has_tile)
+                goto out_drop_ref;
+        return;
+out_drop_ref:
+        if (connector->tile_group) {
+                drm_mode_put_tile_group(connector->dev, connector->tile_group);
+                connector->tile_group = NULL;
+        }
+        return;
+}
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 8f760a2373f9..01744ed79250 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -607,6 +607,15 @@ struct drm_encoder {
  * @bad_edid_counter: track sinks that give us an EDID with invalid checksum
  * @debugfs_entry: debugfs directory for this connector
  * @state: current atomic state for this connector
+ * @has_tile: is this connector connected to a tiled monitor
+ * @tile_group: tile group for the connected monitor
+ * @tile_is_single_monitor: whether the tile is one monitor housing
+ * @num_h_tile: number of horizontal tiles in the tile group
+ * @num_v_tile: number of vertical tiles in the tile group
+ * @tile_h_loc: horizontal location of this tile
+ * @tile_v_loc: vertical location of this tile
+ * @tile_h_size: horizontal size of this tile.
+ * @tile_v_size: vertical size of this tile.
  *
  * Each connector may be connected to one or more CRTCs, or may be clonable by
  * another connector if they can share a CRTC.  Each connector also has a specific
@@ -669,6 +678,15 @@ struct drm_connector {
         struct dentry *debugfs_entry;
 
         struct drm_connector_state *state;
+
+        /* DisplayID bits */
+        bool has_tile;
+        struct drm_tile_group *tile_group;
+        bool tile_is_single_monitor;
+
+        uint8_t num_h_tile, num_v_tile;
+        uint8_t tile_h_loc, tile_v_loc;
+        uint16_t tile_h_size, tile_v_size;
 };
 
 /**