On 9/16/19 11:26 AM, Sakari Ailus wrote:
> Hi Hans,
>
> On Mon, Sep 16, 2019 at 11:00:46AM +0200, Hans Verkuil wrote:
>> Add new macros V4L2_FOURCC_CONV and V4L2_FOURCC_ARGS for use
>> in code that prints a fourcc. These macros can be used in both
>> kernel and userspace.
>>
>> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
>> Suggested-by: Sakari Ailus <sakari.ailus@xxxxxx>
>> ---
>> include/uapi/linux/videodev2.h | 13 +++++++++++++
>> 1 file changed, 13 insertions(+)
>>
>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
>> index 530638dffd93..7a34eb93437e 100644
>> --- a/include/uapi/linux/videodev2.h
>> +++ b/include/uapi/linux/videodev2.h
>> @@ -82,6 +82,19 @@
>> ((__u32)(a) | ((__u32)(b) << 8) | ((__u32)(c) << 16) | ((__u32)(d) << 24))
>> #define v4l2_fourcc_be(a, b, c, d) (v4l2_fourcc(a, b, c, d) | (1U << 31))
>>
>> +/*
>> + * Helper macros to print a fourcc in a standard format. E.g.:
>> + *
>> + * printf("fourcc is " V4L2_FOURCC_CONV "\n", V4L2_FOURCC_ARGS(fourcc));
>> + *
>> + * Note that V4L2_FOURCC_ARGS reuses fourcc, so this can't be an
>> + * expression with side-effects.
>> + */
>> +#define V4L2_FOURCC_CONV "%c%c%c%c%s"
>> +#define V4L2_FOURCC_ARGS(fourcc) \
>> + (fourcc) & 0x7f, ((fourcc) >> 8) & 0x7f, ((fourcc) >> 16) & 0x7f, \
>> + ((fourcc) >> 24) & 0x7f, ((fourcc) & (1U << 31) ? "-BE" : "")
>> +
>> /*
>> * E N U M S
>> */
>
> KernelDoc comments would be nice. Such as in here:
>
> <URL:https://patchwork.linuxtv.org/patch/48372/>
I was searching for old patches with the string 'fourcc', not '4cc',
so that's why I missed your patch.
I'll respin with that (slightly updated) patch.
Regards,
Hans
>
> I'm fine with either patch though.
>
