Some devices (ATI/AMD cards) don't support passing ELD struct to the
hardware but just require filling specific registers and then the
hardware/firmware does the rest. In such cases we need to read the info
from SAD blocks and put them in the correct registers.
---
V2: fix commit message
return number of SADs
take pointer as an argument
break after finding AUDIO_BLOCK
---
drivers/gpu/drm/drm_edid.c | 58 ++++++++++++++++++++++++++++++++++++++++++++
include/drm/drm_edid.h | 24 ++++++++++++++++++
2 files changed, 82 insertions(+)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index e2acfdb..079d97f 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2511,6 +2511,64 @@ void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
EXPORT_SYMBOL(drm_edid_to_eld);
/**
+ * drm_edid_to_sad - extracts SADs from EDID
+ * @edid: EDID to parse
+ * @sads: pointer that will be set to the extracted SADs
+ *
+ * Looks for CEA EDID block and extracts SADs (Short Audio Descriptors) from it.
+ *
+ * Return number of found SADs or negative number on error.
+ */
+int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
+{
+ int count = 0;
+ int i, start, end, dbl;
+ u8 *db, *cea;
+
+ cea = drm_find_cea_extension(edid);
+ if (!cea) {
+ DRM_DEBUG_KMS("SAD: no CEA Extension found\n");
+ return -ENOENT;
+ }
+
+ if (cea_revision(cea) < 3) {
+ DRM_DEBUG_KMS("SAD: wrong CEA revision\n");
+ return -ENOTSUPP;
+ }
+
+ if (cea_db_offsets(cea, &start, &end)) {
+ DRM_DEBUG_KMS("SAD: invalid data block offsets\n");
+ return -EPROTO;
+ }
+
+ for_each_cea_db(cea, i, start, end) {
+ db = &cea[i];
+ dbl = cea_db_payload_len(db);
+
+ if (cea_db_tag(db) == AUDIO_BLOCK) {
+ int j;
+
+ count = dbl / 3; /* SAD is 3B */
+ *sads = kzalloc(count * sizeof(*sads), GFP_KERNEL);
+ if (!*sads)
+ return -ENOMEM;
+ for (j = 0; j < count; j++) {
+ u8 *sad = &db[1 + j * 3];
+
+ (*sads)[j].format = (sad[0] & 0x78) >> 3;
+ (*sads)[j].channels = sad[0] & 0x7;
+ (*sads)[j].freq = sad[1] & 0x7F;
+ (*sads)[j].byte2 = sad[2];
+ }
+ break;
+ }
+ }
+
+ return count;
+}
+EXPORT_SYMBOL(drm_edid_to_sad);
+
+/**
* drm_av_sync_delay - HDMI/DP sink audio-video sync delay in millisecond
* @connector: connector associated with the HDMI/DP sink
* @mode: the display mode
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 5da1b4a..7082c82 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -244,12 +244,36 @@ struct edid {
#define EDID_PRODUCT_ID(e) ((e)->prod_code[0] | ((e)->prod_code[1] << 8))
+#define SAD_FORMAT_LPCM 0x01
+#define SAD_FORMAT_AC3 0x02
+#define SAD_FORMAT_MPEG1 0x03
+#define SAD_FORMAT_MP3 0x04
+#define SAD_FORMAT_MPEG2 0x05
+#define SAD_FORMAT_AAC 0x06
+#define SAD_FORMAT_DTS 0x07
+#define SAD_FORMAT_ATRAC 0x08
+#define SAD_FORMAT_ONE_BIT_AUDIO 0x09
+#define SAD_FORMAT_DOLBY_DIGITAL 0x0a
+#define SAD_FORMAT_DTS_HD 0x0b
+#define SAD_FORMAT_MAT_MLP 0x0c
+#define SAD_FORMAT_DST 0x0d
+#define SAD_FORMAT_WMA_PRO 0x0e
+
+/* Short Audio Descriptor */
+struct cea_sad {
+ u8 format;
+ u8 channels; /* max number of channels - 1 */
+ u8 freq;
+ u8 byte2; /* meaning depends on format */
+};
+
struct drm_encoder;
struct drm_connector;
struct drm_display_mode;
struct hdmi_avi_infoframe;
void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid);
+int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads);
int drm_av_sync_delay(struct drm_connector *connector,
struct drm_display_mode *mode);
struct drm_connector *drm_select_eld(struct drm_encoder *encoder,
--
1.7.10.4
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