[PATCH] drm/fourcc: Add DOC: overview comment

[Brian Starkey]

Hi Matthew,

On Tue, Aug 21, 2018 at 09:26:39AM -0700, Matthew Wilcox wrote:
>On Tue, Aug 21, 2018 at 05:16:11PM +0100, Brian Starkey wrote:
>> There's a number of things which haven't previously been documented
>> around the usage of format modifiers. Capture the current
>> understanding in an overview comment and add it to the rst
>> documentation.
>>
>> Ideally, the generated documentation would also include documentation
>> of all of the #defines, but the kernel-doc system doesn't currently
>> support kernel-doc comments on #define constants.
>
>Can you turn them into enums?  This seems to work ok:
>
>-/* color index */
>-#define DRM_FORMAT_C8          fourcc_code('C', '8', ' ', ' ') /* [7:0] C */
>-
>-/* 8 bpp Red */
>-#define DRM_FORMAT_R8          fourcc_code('R', '8', ' ', ' ') /* [7:0] R */
>+enum {
>+       /* color index */
>+       DRM_FORMAT_C8   = fourcc_code('C', '8', ' ', ' '), /* [7:0] C */
>+       /* 8 bpp Red */
>+       DRM_FORMAT_R8   = fourcc_code('R', '8', ' ', ' '), /* [7:0] R */
>+};
>
>but I appreciate this is user API and maybe there's some code out there
>that does #ifndef DRM_FORMAT_C8 ...

Thanks for the suggestion, Daniel did mention the same. However,
unfortunately I don't think we can safely change the UAPI header in
this manner.

Cheers,
-Brian