drm: add drm_edid_to_eld helper extracting SADs from EDID (v2)
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. agd5f: note that the returned pointer needs to be kfreed as per Christian's suggestion. v2: fix warning Signed-off-by: Rafał Miłecki <zajec5@gmail.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
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@ -2510,6 +2510,65 @@ void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
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}
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EXPORT_SYMBOL(drm_edid_to_eld);
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/**
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* drm_edid_to_sad - extracts SADs from EDID
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* @edid: EDID to parse
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* @sads: pointer that will be set to the extracted SADs
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*
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* Looks for CEA EDID block and extracts SADs (Short Audio Descriptors) from it.
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* Note: returned pointer needs to be kfreed
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*
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* Return number of found SADs or negative number on error.
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*/
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int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
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{
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int count = 0;
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int i, start, end, dbl;
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u8 *cea;
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cea = drm_find_cea_extension(edid);
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if (!cea) {
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DRM_DEBUG_KMS("SAD: no CEA Extension found\n");
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return -ENOENT;
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}
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if (cea_revision(cea) < 3) {
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DRM_DEBUG_KMS("SAD: wrong CEA revision\n");
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return -ENOTSUPP;
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}
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if (cea_db_offsets(cea, &start, &end)) {
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DRM_DEBUG_KMS("SAD: invalid data block offsets\n");
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return -EPROTO;
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}
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for_each_cea_db(cea, i, start, end) {
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u8 *db = &cea[i];
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if (cea_db_tag(db) == AUDIO_BLOCK) {
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int j;
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dbl = cea_db_payload_len(db);
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count = dbl / 3; /* SAD is 3B */
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*sads = kcalloc(count, sizeof(**sads), GFP_KERNEL);
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if (!*sads)
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return -ENOMEM;
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for (j = 0; j < count; j++) {
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u8 *sad = &db[1 + j * 3];
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(*sads)[j].format = (sad[0] & 0x78) >> 3;
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(*sads)[j].channels = sad[0] & 0x7;
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(*sads)[j].freq = sad[1] & 0x7F;
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(*sads)[j].byte2 = sad[2];
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}
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break;
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}
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}
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return count;
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}
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EXPORT_SYMBOL(drm_edid_to_sad);
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/**
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* drm_av_sync_delay - HDMI/DP sink audio-video sync delay in millisecond
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* @connector: connector associated with the HDMI/DP sink
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@ -244,12 +244,21 @@ struct edid {
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#define EDID_PRODUCT_ID(e) ((e)->prod_code[0] | ((e)->prod_code[1] << 8))
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/* Short Audio Descriptor */
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struct cea_sad {
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u8 format;
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u8 channels; /* max number of channels - 1 */
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u8 freq;
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u8 byte2; /* meaning depends on format */
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};
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struct drm_encoder;
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struct drm_connector;
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struct drm_display_mode;
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struct hdmi_avi_infoframe;
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void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid);
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int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads);
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int drm_av_sync_delay(struct drm_connector *connector,
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struct drm_display_mode *mode);
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struct drm_connector *drm_select_eld(struct drm_encoder *encoder,
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