Re: [PATCH] simplefb: add support for a8b8g8r8 pixel format

[Alex Courbot <acourbot@nvidia.com>]

On 06/06/2013 05:24 PM, Jean-Christophe PLAGNIOL-VILLARD wrote:
>
> On Jun 6, 2013, at 10:12 AM, Alex Courbot <acourbot@nvidia.com> wrote:
>
>> On 06/06/2013 04:59 PM, Jean-Christophe PLAGNIOL-VILLARD wrote:
>>>
>>> On Jun 6, 2013, at 9:20 AM, Alexandre Courbot <acourbot@nvidia.com> wrote:
>>>
>>>> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
>>>> ---
>>>> Documentation/devicetree/bindings/video/simple-framebuffer.txt | 1 +
>>>> drivers/video/simplefb.c                                       | 1 +
>>>> 2 files changed, 2 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/video/simple-framebuffer.txt b/Documentation/devicetree/bindings/video/simple-framebuffer.txt
>>>> index 3ea4605..70c26f3 100644
>>>> --- a/Documentation/devicetree/bindings/video/simple-framebuffer.txt
>>>> +++ b/Documentation/devicetree/bindings/video/simple-framebuffer.txt
>>>> @@ -12,6 +12,7 @@ Required properties:
>>>> - stride: The number of bytes in each line of the framebuffer.
>>>> - format: The format of the framebuffer surface. Valid values are:
>>>>    - r5g6b5 (16-bit pixels, d[15:11]=r, d[10:5]=g, d[4:0]=b).
>>>> +  - a8b8g8r8 (32-bit pixels, d[31:24]=a, d[23:16]=b, d[15:8]=g, d[7:0]=r).
>>>>
>>>> Example:
>>>>
>>>> diff --git a/drivers/video/simplefb.c b/drivers/video/simplefb.c
>>>> index e2e9e3e..d7041aa 100644
>>>> --- a/drivers/video/simplefb.c
>>>> +++ b/drivers/video/simplefb.c
>>>> @@ -84,6 +84,7 @@ struct simplefb_format {
>>>>
>>>> static struct simplefb_format simplefb_formats[] = {
>>>> 	{ "r5g6b5", 16, {11, 5}, {5, 6}, {0, 5}, {0, 0} },
>>>> +	{ "a8b8g8r8", 32, {0, 8}, {8, 8}, {16, 8}, {31, 8} },
>>>
>>> why don't you parse the string?
>>>
>>> so you will a real generic bindings
>>
>> Tried that already, got NACKed: https://lkml.org/lkml/2013/5/27/330
>>
>> The list of modes of this driver should not grow too big. Even in terms of footprint I'd say the list should remain smaller than the parsing code.
>>
>> What we can discuss though is whether we want to keep this a8b8g8r8 syntax or switch to something more standard, say "rgba8888".
>
> I'm going to be very honest I do not like the simplefb driver from the beginning
> but I do found it useful. And as said in it's name it need to be *SIMPLE*
>
> Then a huge list of compatible no way
> otherwise we drop this from the simplefb and make it a generic helper
>
> I do not want to see format parser in every drivers this need to handle at video framework level
>
> If I see that we start to increase again and again the simplefb I will not accept
> to merge the code as we must keep it simple

In that case it's probably better to maintain a "simple" list of 
supported modes, which is what this patch does.

Alex.