* Copyright (c) 2006 Luc Verhaegen (quirks list)
* Copyright (c) 2007-2008 Intel Corporation
* Jesse Barnes <jesse.barnes@intel.com>
+ * Copyright 2010 Red Hat, Inc.
*
* DDC probing routines (drm_ddc_read & drm_do_probe_ddc_edid) originally from
* FB layer.
{ "SAM", 638, EDID_QUIRK_PREFER_LARGE_60 },
};
+/*** DDC fetch and block validation ***/
-/* Valid EDID header has these bytes */
static const u8 edid_header[] = {
0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00
};
-/**
- * drm_edid_is_valid - sanity check EDID data
- * @edid: EDID data
- *
- * Sanity check the EDID block by looking at the header, the version number
- * and the checksum. Return 0 if the EDID doesn't check out, or 1 if it's
- * valid.
+/*
+ * Sanity check the EDID block (base or extension). Return 0 if the block
+ * doesn't check out, or 1 if it's valid.
*/
-bool drm_edid_is_valid(struct edid *edid)
+static bool
+drm_edid_block_valid(u8 *raw_edid)
{
- int i, score = 0;
+ int i;
u8 csum = 0;
- u8 *raw_edid = (u8 *)edid;
+ struct edid *edid = (struct edid *)raw_edid;
- for (i = 0; i < sizeof(edid_header); i++)
- if (raw_edid[i] == edid_header[i])
- score++;
+ if (raw_edid[0] == 0x00) {
+ int score = 0;
- if (score == 8) ;
- else if (score >= 6) {
- DRM_DEBUG("Fixing EDID header, your hardware may be failing\n");
- memcpy(raw_edid, edid_header, sizeof(edid_header));
- } else
- goto bad;
+ for (i = 0; i < sizeof(edid_header); i++)
+ if (raw_edid[i] == edid_header[i])
+ score++;
+
+ if (score == 8) ;
+ else if (score >= 6) {
+ DRM_DEBUG("Fixing EDID header, your hardware may be failing\n");
+ memcpy(raw_edid, edid_header, sizeof(edid_header));
+ } else {
+ goto bad;
+ }
+ }
for (i = 0; i < EDID_LENGTH; i++)
csum += raw_edid[i];
goto bad;
}
- if (edid->version != 1) {
- DRM_ERROR("EDID has major version %d, instead of 1\n", edid->version);
- goto bad;
- }
+ /* per-block-type checks */
+ switch (raw_edid[0]) {
+ case 0: /* base */
+ if (edid->version != 1) {
+ DRM_ERROR("EDID has major version %d, instead of 1\n", edid->version);
+ goto bad;
+ }
- if (edid->revision > 4)
- DRM_DEBUG("EDID minor > 4, assuming backward compatibility\n");
+ if (edid->revision > 4)
+ DRM_DEBUG("EDID minor > 4, assuming backward compatibility\n");
+ break;
+
+ default:
+ break;
+ }
return 1;
}
return 0;
}
+
+/**
+ * drm_edid_is_valid - sanity check EDID data
+ * @edid: EDID data
+ *
+ * Sanity-check an entire EDID record (including extensions)
+ */
+bool drm_edid_is_valid(struct edid *edid)
+{
+ int i;
+ u8 *raw = (u8 *)edid;
+
+ if (!edid)
+ return false;
+
+ for (i = 0; i <= edid->extensions; i++)
+ if (!drm_edid_block_valid(raw + i * EDID_LENGTH))
+ return false;
+
+ return true;
+}
EXPORT_SYMBOL(drm_edid_is_valid);
+#define DDC_ADDR 0x50
+#define DDC_SEGMENT_ADDR 0x30
+/**
+ * Get EDID information via I2C.
+ *
+ * \param adapter : i2c device adaptor
+ * \param buf : EDID data buffer to be filled
+ * \param len : EDID data buffer length
+ * \return 0 on success or -1 on failure.
+ *
+ * Try to fetch EDID information by calling i2c driver function.
+ */
+static int
+drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
+ int block, int len)
+{
+ unsigned char start = block * EDID_LENGTH;
+ struct i2c_msg msgs[] = {
+ {
+ .addr = DDC_ADDR,
+ .flags = 0,
+ .len = 1,
+ .buf = &start,
+ }, {
+ .addr = DDC_ADDR,
+ .flags = I2C_M_RD,
+ .len = len,
+ .buf = buf + start,
+ }
+ };
+
+ if (i2c_transfer(adapter, msgs, 2) == 2)
+ return 0;
+
+ return -1;
+}
+
+static u8 *
+drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
+{
+ int i, j = 0;
+ u8 *block, *new;
+
+ if ((block = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
+ return NULL;
+
+ /* base block fetch */
+ for (i = 0; i < 4; i++) {
+ if (drm_do_probe_ddc_edid(adapter, block, 0, EDID_LENGTH))
+ goto out;
+ if (drm_edid_block_valid(block))
+ break;
+ }
+ if (i == 4)
+ goto carp;
+
+ /* if there's no extensions, we're done */
+ if (block[0x7e] == 0)
+ return block;
+
+ new = krealloc(block, (block[0x7e] + 1) * EDID_LENGTH, GFP_KERNEL);
+ if (!new)
+ goto out;
+ block = new;
+
+ for (j = 1; j <= block[0x7e]; j++) {
+ for (i = 0; i < 4; i++) {
+ if (drm_do_probe_ddc_edid(adapter, block, j,
+ EDID_LENGTH))
+ goto out;
+ if (drm_edid_block_valid(block + j * EDID_LENGTH))
+ break;
+ }
+ if (i == 4)
+ goto carp;
+ }
+
+ return block;
+
+carp:
+ dev_warn(&connector->dev->pdev->dev, "%s: EDID block %d invalid.\n",
+ drm_get_connector_name(connector), j);
+
+out:
+ kfree(block);
+ return NULL;
+}
+
+/**
+ * Probe DDC presence.
+ *
+ * \param adapter : i2c device adaptor
+ * \return 1 on success
+ */
+static bool
+drm_probe_ddc(struct i2c_adapter *adapter)
+{
+ unsigned char out;
+
+ return (drm_do_probe_ddc_edid(adapter, &out, 0, 1) == 0);
+}
+
+/**
+ * drm_get_edid - get EDID data, if available
+ * @connector: connector we're probing
+ * @adapter: i2c adapter to use for DDC
+ *
+ * Poke the given i2c channel to grab EDID data if possible. If found,
+ * attach it to the connector.
+ *
+ * Return edid data or NULL if we couldn't find any.
+ */
+struct edid *drm_get_edid(struct drm_connector *connector,
+ struct i2c_adapter *adapter)
+{
+ struct edid *edid = NULL;
+
+ if (drm_probe_ddc(adapter))
+ edid = (struct edid *)drm_do_get_edid(connector, adapter);
+
+ connector->display_info.raw_edid = (char *)edid;
+
+ return edid;
+
+}
+EXPORT_SYMBOL(drm_get_edid);
+
+/*** EDID parsing ***/
+
/**
* edid_vendor - match a string against EDID's obfuscated vendor field
* @edid: EDID to match
return modes;
}
-#define DDC_ADDR 0x50
-/**
- * Get EDID information via I2C.
- *
- * \param adapter : i2c device adaptor
- * \param buf : EDID data buffer to be filled
- * \param len : EDID data buffer length
- * \return 0 on success or -1 on failure.
- *
- * Try to fetch EDID information by calling i2c driver function.
- */
-int drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
- unsigned char *buf, int len)
-{
- unsigned char start = 0x0;
- struct i2c_msg msgs[] = {
- {
- .addr = DDC_ADDR,
- .flags = 0,
- .len = 1,
- .buf = &start,
- }, {
- .addr = DDC_ADDR,
- .flags = I2C_M_RD,
- .len = len,
- .buf = buf,
- }
- };
-
- if (i2c_transfer(adapter, msgs, 2) == 2)
- return 0;
-
- return -1;
-}
-EXPORT_SYMBOL(drm_do_probe_ddc_edid);
-
-static int drm_ddc_read_edid(struct drm_connector *connector,
- struct i2c_adapter *adapter,
- char *buf, int len)
-{
- int i;
-
- for (i = 0; i < 4; i++) {
- if (drm_do_probe_ddc_edid(adapter, buf, len))
- return -1;
- if (drm_edid_is_valid((struct edid *)buf))
- return 0;
- }
-
- /* repeated checksum failures; warn, but carry on */
- dev_warn(&connector->dev->pdev->dev, "%s: EDID invalid.\n",
- drm_get_connector_name(connector));
- return -1;
-}
-
-/**
- * drm_get_edid - get EDID data, if available
- * @connector: connector we're probing
- * @adapter: i2c adapter to use for DDC
- *
- * Poke the given connector's i2c channel to grab EDID data if possible.
- *
- * Return edid data or NULL if we couldn't find any.
- */
-struct edid *drm_get_edid(struct drm_connector *connector,
- struct i2c_adapter *adapter)
-{
- int ret;
- struct edid *edid;
-
- edid = kmalloc(EDID_LENGTH * (DRM_MAX_EDID_EXT_NUM + 1),
- GFP_KERNEL);
- if (edid == NULL) {
- dev_warn(&connector->dev->pdev->dev,
- "Failed to allocate EDID\n");
- goto end;
- }
-
- /* Read first EDID block */
- ret = drm_ddc_read_edid(connector, adapter,
- (unsigned char *)edid, EDID_LENGTH);
- if (ret != 0)
- goto clean_up;
-
- /* There are EDID extensions to be read */
- if (edid->extensions != 0) {
- int edid_ext_num = edid->extensions;
-
- if (edid_ext_num > DRM_MAX_EDID_EXT_NUM) {
- dev_warn(&connector->dev->pdev->dev,
- "The number of extension(%d) is "
- "over max (%d), actually read number (%d)\n",
- edid_ext_num, DRM_MAX_EDID_EXT_NUM,
- DRM_MAX_EDID_EXT_NUM);
- /* Reset EDID extension number to be read */
- edid_ext_num = DRM_MAX_EDID_EXT_NUM;
- }
- /* Read EDID including extensions too */
- ret = drm_ddc_read_edid(connector, adapter, (char *)edid,
- EDID_LENGTH * (edid_ext_num + 1));
- if (ret != 0)
- goto clean_up;
-
- }
-
- connector->display_info.raw_edid = (char *)edid;
- goto end;
-
-clean_up:
- kfree(edid);
- edid = NULL;
-end:
- return edid;
-
-}
-EXPORT_SYMBOL(drm_get_edid);
-
#define HDMI_IDENTIFIER 0x000C03
#define VENDOR_BLOCK 0x03
/**
git.openpandora.org / pandora-kernel.git / commitdiff