[v2 04/14] drm: Parse Colorimetry data block from EDID

[Sharma, Shashank]

On 1/8/2019 12:10 PM, Shankar, Uma wrote:
>
>> -----Original Message-----
>> From: dri-devel [mailto:dri-devel-bounces at lists.freedesktop.org] On Behalf Of
>> Sharma, Shashank
>> Sent: Thursday, December 20, 2018 11:54 PM
>> To: Shankar, Uma <uma.shankar at intel.com>; intel-gfx at lists.freedesktop.org;
>> dri-devel at lists.freedesktop.org
>> Cc: Syrjala, Ville <ville.syrjala at intel.com>; Lankhorst, Maarten
>> <maarten.lankhorst at intel.com>
>> Subject: Re: [v2 04/14] drm: Parse Colorimetry data block from EDID
>>
>> Regards
>>
>> Shashank
>>
>>
>> On 12/12/2018 2:08 AM, Uma Shankar wrote:
>>> CEA 861.3 spec adds colorimetry data block for HDMI.
>>> Parsing the block to get the colorimetry data from panel.
>>>
>>> v2: Rebase
>>>
>>> Signed-off-by: Uma Shankar <uma.shankar at intel.com>
>>> ---
>>>    drivers/gpu/drm/drm_edid.c  | 24 ++++++++++++++++++++++++
>>>    include/drm/drm_connector.h |  2 ++
>>>    2 files changed, 26 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>>> index d12b74e..344d8c1 100644
>>> --- a/drivers/gpu/drm/drm_edid.c
>>> +++ b/drivers/gpu/drm/drm_edid.c
>>> @@ -3818,6 +3818,28 @@ static void fixup_detailed_cea_mode_clock(struct
>> drm_display_mode *mode)
>>>    	mode->clock = clock;
>>>    }
>>>
>>> +static bool cea_db_is_hdmi_colorimetry_data_block(const u8 *db) {
>>> +	if (cea_db_tag(db) != DATA_BLOCK_EXTENDED_TAG)
>>> +		return false;
>>> +
>>> +	if (db[1] != COLORIMETRY_DATA_BLOCK)
>>> +
>> Again, the COLORIMETRY_DATA_BLOCK definition should be added into this
>> patch.
> Ok, will do that.
>
>>> 	return false;
>>> +
>>> +	return true;
>>> +}
>>> +
>>> +static void
>>> +drm_parse_colorimetry_data_block(struct drm_connector *connector,
>>> +const u8 *db) {
>>> +	struct drm_hdmi_info *info = &connector->display_info.hdmi;
>>> +	uint16_t len;
>>> +
>>> +	len = cea_db_payload_len(db);
>> Again, the return value of this function doesn't account for extended db tag byte,
>> so what we are looking for is len -1
> Will update this.
>
>>> +	info->colorimetry = db[2];
>> colorimetry block is actually db[2] and db[3].bit7 (which represents
>> DCI-P3 space), so we probably want to make info->colorimetryuint16_t
> 3 BT2020RGB BT2020YCC BT2020cYCC AdobeRGB AdobeYCC601 sYCC601 xvYCC709 xvYCC601
> 4 F47=0 F46=0 F45=0 F44=0 MD3 MD2 MD1 MD0
>
> This is how db[2] and db[3] is described in spec. There is not much clarity on F47. Not sure if they
> are for DCI-P3, can you clarify once.
Ah, check CEA-861-G table 70, there there is no F47, but I could see 
DCI-P3 in that place, which spec is that you are following right now ?
- Shashank
> Regards,
> Uma Shankar
>
>>> +}
>>> +
>>> +
>>>    static bool cea_db_is_hdmi_hdr_metadata_block(const u8 *db)
>>>    {
>>>    	if (cea_db_tag(db) != DATA_BLOCK_EXTENDED_TAG) @@ -4513,6
>> +4535,8
>>> @@ static void drm_parse_cea_ext(struct drm_connector *connector,
>>>    			drm_parse_y420cmdb_bitmap(connector, db);
>>>    		if (cea_db_is_hdmi_hdr_metadata_block(db))
>>>    			drm_parse_hdr_metadata_block(connector, db);
>>> +		if (cea_db_is_hdmi_colorimetry_data_block(db))
>>> +			drm_parse_colorimetry_data_block(connector, db);
>>>    	}
>>>    }
>>>
>>> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
>>> index 2ee45dc..90ce364 100644
>>> --- a/include/drm/drm_connector.h
>>> +++ b/include/drm/drm_connector.h
>>> @@ -206,6 +206,8 @@ struct drm_hdmi_info {
>>>
>>>    	/** @y420_dc_modes: bitmap of deep color support index */
>>>    	u8 y420_dc_modes;
>>> +
>> Please add a one line description about this variable.
> Sure will update this.
>
>>> +	u8 colorimetry;
>>>    };
>>>
>>>    /**
>> Shashank
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