From fe214163cc6e6b33253b7ac14bc3dd616e76b513 Mon Sep 17 00:00:00 2001 From: Rafał Miłecki Date: Fri, 19 Apr 2013 19:01:25 +0200 Subject: drm: add drm_edid_to_eld helper extracting SADs from EDID (v2) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Christian König Signed-off-by: Alex Deucher --- drivers/gpu/drm/drm_edid.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++ include/drm/drm_edid.h | 9 +++++++ 2 files changed, 68 insertions(+) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index e2acfdbf7d3c..b6807e881a60 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -2510,6 +2510,65 @@ 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. + * Note: returned pointer needs to be kfreed + * + * 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 *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) { + u8 *db = &cea[i]; + + if (cea_db_tag(db) == AUDIO_BLOCK) { + int j; + dbl = cea_db_payload_len(db); + + count = dbl / 3; /* SAD is 3B */ + *sads = kcalloc(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 diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h index 5da1b4ae7d84..fc481fc17085 100644 --- a/include/drm/drm_edid.h +++ b/include/drm/drm_edid.h @@ -244,12 +244,21 @@ struct edid { #define EDID_PRODUCT_ID(e) ((e)->prod_code[0] | ((e)->prod_code[1] << 8)) +/* 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, -- cgit v1.2.3