Re: [PATCH v3 4/6] drm: bridge: dw-hdmi: Switch to V4L bus format and encodings

[Neil Armstrong <narmstrong@baylibre.com>]

On 03/13/2017 12:43 PM, Jose Abreu wrote:
> Hi Neil,
> 
> 
> On 09-03-2017 14:27, Jose Abreu wrote:
>> Hi Neil,
>>
>>
>> On 08-03-2017 12:12, Neil Armstrong wrote:
>>> Hi Jose,
>>>
>>> It seems here that we only have the RGB444<->YUV444 8bit tables, from the Amlogic
>>> source I have the following for 10bit, 12bit and 16bit for itu601 :
>>>
>>> static const u16 csc_coeff_rgb_out_eitu601_10b[3][4] = {
>>> 	{ 0x2000, 0x6926, 0x74fd, 0x043b },
>>> 	{ 0x2000, 0x2cdd, 0x0000, 0x7a65 },
>>> 	{ 0x2000, 0x0000, 0x38b4, 0x78ea }
>>> };
>>>
>>> static const u16 csc_coeff_rgb_out_eitu601_12b_16b[3][4] = {
>>> 	{ 0x2000, 0x6926, 0x74fd, 0x10ee },
>>> 	{ 0x2000, 0x2cdd, 0x0000, 0x6992 },
>>> 	{ 0x2000, 0x0000, 0x38b4, 0x63a6 }
>>> };
>> These two do not match anything I have here.
>>
>>> static const u16 csc_coeff_rgb_in_eitu601_10b[3][4] = {
>>> 	{ 0x2591, 0x1322, 0x074b, 0x0000 },
>>> 	{ 0x6535, 0x2000, 0x7acc, 0x0800 },
>>> 	{ 0x6acd, 0x7534, 0x2000, 0x0800 }
>>> };
>> This is more or less correct, I have small offsets. Note that I
>> even have offsets with the values that are in dw-hdmi driver,
>> which can be caused because I'm seeing the latest document that
>> contain these values. I guess they were updated.
>>
>>> static const u16 csc_coeff_rgb_in_eitu601_12b_16b[3][4] = {
>>> 	{ 0x2591, 0x1322, 0x074b, 0x0000 },
>>> 	{ 0x6535, 0x2000, 0x7acc, 0x2000 },
>>> 	{ 0x6acd, 0x7534, 0x2000, 0x2000 }
>>> };
>> The same for this.
>>
>>> But I miss the itu709 values.
>>>
>>> Could you confirm these values and maybe provide the itu709 values ?
>> I will have to check if I can provide you the values. I will get
>> back to you.
> 
> Sorry but looks like I won't be able to provide you the correct
> values :/ If you are working for a Synopsys customer you can
> contact our CAE (If so I can guide you to the correct CAE).
> 
> Anyway, unless you can test the values you have I suggest you
> don't use them, they do not match what I have here and I can't
> test them because right now I don't have a setup (I'm assuming
> that your CSC block within the controller was not modified).
> 
> Best regards,
> Jose Miguel Abreu
> 

Hi Jose,

Thanks for your effort, I will postpone this fix and only add the tables
needed by the Amlogic platform when needed.

Thanks,
Neil