On Wed, Aug 14, 2013 at 4:14 AM, Ville Syrjälä
<ville.syrjala@xxxxxxxxxxxxxxx> wrote:
> On Tue, Aug 13, 2013 at 05:01:38PM -0400, Alex Deucher wrote:
>> This adds a helper function to extract the speaker allocation
>> data block from the EDID. This data block describes what speakers
>> are present on the display device.
>>
>> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
>> ---
>> drivers/gpu/drm/drm_edid.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++
>> include/drm/drm_edid.h | 1 +
>> 2 files changed, 51 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>> index 70fc133..bc16c80 100644
>> --- a/drivers/gpu/drm/drm_edid.c
>> +++ b/drivers/gpu/drm/drm_edid.c
>> @@ -2735,6 +2735,56 @@ int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
>> EXPORT_SYMBOL(drm_edid_to_sad);
>>
>> /**
>> + * drm_edid_to_speaker_allocation - extracts Speaker Allocation Data Blocks from EDID
>> + * @edid: EDID to parse
>> + * @sadb: pointer to the speaker block
>> + *
>> + * Looks for CEA EDID block and extracts the Speaker Allocation Data Block from it.
>> + *
>> + * Return number of found Speaker Allocation Blocks or negative number on error.
>> + */
>> +int drm_edid_to_speaker_allocation(struct edid *edid, u8 *sadb)
>> +{
>> + int count = 0;
>> + int i, start, end, dbl;
>> + u8 *cea;
>
> Can be const.
>
fixed.
>> +
>> + 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];
>
> Also const.
fixed.
>
>> +
>> + if (cea_db_tag(db) == SPEAKER_BLOCK) {
>> + dbl = cea_db_payload_len(db);
>> +
>> + /* Speaker Allocation Data Block */
>> + if (dbl >= 1) {
>
> CEA-861-E says the length must be exactly 3. Maybe we should be
> strict with this check?
>
Sure.
> Also the second payload byte also contains three valid bits. Do
> we not care about those speakers?
Updated patches on the way.
Alex
>
>> + *sadb = db[1];
>> + count = 1;
>> + break;
>> + }
>> + }
>> + }
>> +
>> + return count;
>> +}
>> +EXPORT_SYMBOL(drm_edid_to_speaker_allocation);
>> +
>> +/**
>> * 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 fc481fc..22d7985 100644
>> --- a/include/drm/drm_edid.h
>> +++ b/include/drm/drm_edid.h
>> @@ -259,6 +259,7 @@ 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_edid_to_speaker_allocation(struct edid *edid, u8 *sadb);
>> int drm_av_sync_delay(struct drm_connector *connector,
>> struct drm_display_mode *mode);
>> struct drm_connector *drm_select_eld(struct drm_encoder *encoder,
>> --
>> 1.8.3.1
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@xxxxxxxxxxxxxxxxxxxxx
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Ville Syrjälä
> Intel OTC
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