Am 19.04.2013 19:01, schrieb Rafa? Mi?ecki:
> 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.
>
> Signed-off-by: Rafa? Mi?ecki <zajec5 at gmail.com>
Maybe add some comment that the returned pointer needs to be kfreed, but
apart from that it is good enough for me and:
Reviewed-by: Christian K?nig <christian.koenig at amd.com>
> ---
> Changes since RFC:
> 1) Fixed allocation (and kcalloc instead of kzalloc)
> 2) Don't duplicate defines for audio codecs
> 3) Some variables scope
> ---
> drivers/gpu/drm/drm_edid.c | 58
> ++++++++++++++++++++++++++++++++++++++++++++
> include/drm/drm_edid.h | 9 +++++++
> 2 files changed, 67 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index e2acfdb..89ae211 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 *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) {
> + dbl = cea_db_payload_len(db);
> + int j;
> +
> + 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
> * @mode: the display mode
> diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
> index 5da1b4a..fc481fc 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,
