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path: root/drivers/gpu/drm/drm_edid.c
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Diffstat (limited to 'drivers/gpu/drm/drm_edid.c')
-rw-r--r--drivers/gpu/drm/drm_edid.c189
1 files changed, 174 insertions, 15 deletions
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 21cc45cf3367..53bc7a628909 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 +1015,9 @@ 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);
+
static int drm_edid_block_checksum(const u8 *raw_edid)
{
int i;
@@ -1145,9 +1149,9 @@ EXPORT_SYMBOL(drm_edid_is_valid);
* Return: 0 on success or -1 on failure.
*/
static int
-drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
- int block, int len)
+drm_do_probe_ddc_edid(void *data, u8 *buf, unsigned int block, size_t len)
{
+ struct i2c_adapter *adapter = data;
unsigned char start = block * EDID_LENGTH;
unsigned char segment = block >> 1;
unsigned char xfers = segment ? 3 : 2;
@@ -1196,8 +1200,26 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
return ret == xfers ? 0 : -1;
}
-static u8 *
-drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
+/**
+ * drm_do_get_edid - get EDID data using a custom EDID block read function
+ * @connector: connector we're probing
+ * @get_edid_block: EDID block read function
+ * @data: private data passed to the block read function
+ *
+ * When the I2C adapter connected to the DDC bus is hidden behind a device that
+ * exposes a different interface to read EDID blocks this function can be used
+ * to get EDID data using a custom block read function.
+ *
+ * As in the general case the DDC bus is accessible by the kernel at the I2C
+ * level, drivers must make all reasonable efforts to expose it as an I2C
+ * adapter and use drm_get_edid() instead of abusing this function.
+ *
+ * Return: Pointer to valid EDID or NULL if we couldn't find any.
+ */
+struct edid *drm_do_get_edid(struct drm_connector *connector,
+ int (*get_edid_block)(void *data, u8 *buf, unsigned int block,
+ size_t len),
+ void *data)
{
int i, j = 0, valid_extensions = 0;
u8 *block, *new;
@@ -1208,7 +1230,7 @@ drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
/* base block fetch */
for (i = 0; i < 4; i++) {
- if (drm_do_probe_ddc_edid(adapter, block, 0, EDID_LENGTH))
+ if (get_edid_block(data, block, 0, EDID_LENGTH))
goto out;
if (drm_edid_block_valid(block, 0, print_bad_edid))
break;
@@ -1222,7 +1244,7 @@ drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
/* if there's no extensions, we're done */
if (block[0x7e] == 0)
- return block;
+ return (struct edid *)block;
new = krealloc(block, (block[0x7e] + 1) * EDID_LENGTH, GFP_KERNEL);
if (!new)
@@ -1231,7 +1253,7 @@ drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
for (j = 1; j <= block[0x7e]; j++) {
for (i = 0; i < 4; i++) {
- if (drm_do_probe_ddc_edid(adapter,
+ if (get_edid_block(data,
block + (valid_extensions + 1) * EDID_LENGTH,
j, EDID_LENGTH))
goto out;
@@ -1259,7 +1281,7 @@ drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
block = new;
}
- return block;
+ return (struct edid *)block;
carp:
if (print_bad_edid) {
@@ -1272,6 +1294,7 @@ out:
kfree(block);
return NULL;
}
+EXPORT_SYMBOL_GPL(drm_do_get_edid);
/**
* drm_probe_ddc() - probe DDC presence
@@ -1301,11 +1324,14 @@ EXPORT_SYMBOL(drm_probe_ddc);
struct edid *drm_get_edid(struct drm_connector *connector,
struct i2c_adapter *adapter)
{
- struct edid *edid = NULL;
+ struct edid *edid;
- if (drm_probe_ddc(adapter))
- edid = (struct edid *)drm_do_get_edid(connector, adapter);
+ if (!drm_probe_ddc(adapter))
+ return NULL;
+ 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);
@@ -2401,7 +2427,7 @@ 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;
@@ -2413,7 +2439,7 @@ 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;
}
@@ -2423,6 +2449,16 @@ 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.)
@@ -3140,9 +3176,12 @@ void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
}
}
eld[5] |= sad_count << 4;
- eld[2] = (20 + mnl + sad_count * 3 + 3) / 4;
- DRM_DEBUG_KMS("ELD size %d, SAD count %d\n", (int)eld[2], sad_count);
+ eld[DRM_ELD_BASELINE_ELD_LEN] =
+ DIV_ROUND_UP(drm_eld_calc_baseline_block_size(eld), 4);
+
+ DRM_DEBUG_KMS("ELD size %d, SAD count %d\n",
+ drm_eld_size(eld), sad_count);
}
EXPORT_SYMBOL(drm_edid_to_eld);
@@ -3880,3 +3919,123 @@ 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;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.