}
EXPORT_SYMBOL(drm_edid_read);
-static u32 edid_extract_panel_id(const struct edid *edid)
+/**
+ * drm_edid_get_panel_id - Get a panel's ID from EDID
+ * @drm_edid: EDID that contains panel ID.
+ *
+ * This function uses the first block of the EDID of a panel and (assuming
+ * that the EDID is valid) extracts the ID out of it. The ID is a 32-bit value
+ * (16 bits of manufacturer ID and 16 bits of per-manufacturer ID) that's
+ * supposed to be different for each different modem of panel.
+ *
+ * Return: A 32-bit ID that should be different for each make/model of panel.
+ * See the functions drm_edid_encode_panel_id() and
+ * drm_edid_decode_panel_id() for some details on the structure of this
+ * ID. Return 0 if the EDID size is less than a base block.
+ */
+u32 drm_edid_get_panel_id(const struct drm_edid *drm_edid)
{
+ const struct edid *edid = drm_edid->edid;
+
+ if (drm_edid->size < EDID_LENGTH)
+ return 0;
+
/*
* We represent the ID as a 32-bit number so it can easily be compared
* with "==".
(u32)edid->mfg_id[1] << 16 |
(u32)EDID_PRODUCT_ID(edid);
}
+EXPORT_SYMBOL(drm_edid_get_panel_id);
/**
- * drm_edid_get_panel_id - Get a panel's ID through DDC
+ * drm_edid_read_base_block - Get a panel's EDID base block
* @adapter: I2C adapter to use for DDC
*
- * This function reads the first block of the EDID of a panel and (assuming
- * that the EDID is valid) extracts the ID out of it. The ID is a 32-bit value
- * (16 bits of manufacturer ID and 16 bits of per-manufacturer ID) that's
- * supposed to be different for each different modem of panel.
+ * This function returns the drm_edid containing the first block of the EDID of
+ * a panel.
*
* This function is intended to be used during early probing on devices where
* more than one panel might be present. Because of its intended use it must
- * assume that the EDID of the panel is correct, at least as far as the ID
- * is concerned (in other words, we don't process any overrides here).
+ * assume that the EDID of the panel is correct, at least as far as the base
+ * block is concerned (in other words, we don't process any overrides here).
+ *
+ * Caller should call drm_edid_free() after use.
*
* NOTE: it's expected that this function and drm_do_get_edid() will both
* be read the EDID, but there is no caching between them. Since we're only
* reading the first block, hopefully this extra overhead won't be too big.
*
- * Return: A 32-bit ID that should be different for each make/model of panel.
- * See the functions drm_edid_encode_panel_id() and
- * drm_edid_decode_panel_id() for some details on the structure of this
- * ID.
+ * WARNING: Only use this function when the connector is unknown. For example,
+ * during the early probe of panel. The EDID read from the function is temporary
+ * and should be replaced by the full EDID returned from other drm_edid_read.
+ *
+ * Return: Pointer to allocated EDID base block, or NULL on any failure.
*/
-
-u32 drm_edid_get_panel_id(struct i2c_adapter *adapter)
+const struct drm_edid *drm_edid_read_base_block(struct i2c_adapter *adapter)
{
enum edid_block_status status;
void *base_block;
- u32 panel_id = 0;
-
- /*
- * There are no manufacturer IDs of 0, so if there is a problem reading
- * the EDID then we'll just return 0.
- */
base_block = kzalloc(EDID_LENGTH, GFP_KERNEL);
if (!base_block)
- return 0;
+ return NULL;
status = edid_block_read(base_block, 0, drm_do_probe_ddc_edid, adapter);
edid_block_status_print(status, base_block, 0);
- if (edid_block_status_valid(status, edid_block_tag(base_block)))
- panel_id = edid_extract_panel_id(base_block);
- else
+ if (!edid_block_status_valid(status, edid_block_tag(base_block))) {
edid_block_dump(KERN_NOTICE, base_block, 0);
+ kfree(base_block);
+ return NULL;
+ }
- kfree(base_block);
-
- return panel_id;
+ return _drm_edid_alloc(base_block, EDID_LENGTH);
}
-EXPORT_SYMBOL(drm_edid_get_panel_id);
+EXPORT_SYMBOL(drm_edid_read_base_block);
/**
* drm_get_edid_switcheroo - get EDID data for a vga_switcheroo output
*/
static u32 edid_get_quirks(const struct drm_edid *drm_edid)
{
- u32 panel_id = edid_extract_panel_id(drm_edid->edid);
+ u32 panel_id = drm_edid_get_panel_id(drm_edid);
const struct edid_quirk *quirk;
int i;