Re: [PATCH 0/2] media: imx: add capture support for RGB565_2X8 on parallel bus

[Steve Longerbeam <slongerbeam@gmail.com>]

Hi Jan,


On 05/08/2018 07:13 AM, Jan Lübbe wrote:
> Hi,
>
> On Mon, 2018-05-07 at 11:21 -0700, Steve Longerbeam wrote:
>> In other words, if the sensor bus is parallel, only 8-bit bus UYVY_2x8
>> and YUYV_2x8 can be routed to the IC pad or component packed/unpacked
>> by the IDMAC pad. All other sensor formats on a parallel bus (8 or 16
>> bit) must be sent to IDMAC pad as pass-through.
>>
>> I think the code can be simplified/made more readable because of this,
>> something like:
>>
>> static inline bool is_parallel_bus(struct v4l2_fwnode_endpoint *ep)
>> {
>>           return ep->bus_type != V4L2_MBUS_CSI2;
>> }
>>
>> static inline bool requires_pass_through(
>>       struct v4l2_fwnode_endpoint *ep,
>>       struct v4l2_mbus_framefmt *infmt,
>>       const struct imx_media_pixfmt *incc) {
>>           return incc->bayer || (is_parallel_bus(ep) && infmt->code !=
>> UYVY_2x8 && infmt->code != YUYV_2x8);
>> }
>>
>>
>> Then requires_pass_through() can be used everywhere we need to
>> determine the pass-though requirement.
> OK, i've added these helper functions. In csi_link_validate() we don't
> have the infmt handy, but as the downstream elements check if they have
> a native format anyway, this check is redundant and so i've dropped it.

Makes sense.

>
>> Also, there's something wrong with the 'switch (image.pix.pixelformat)
>> {...}' block in csi_idmac_setup_channel(). Pass-though, burst size, pass-though
>> bits, should be determined by input media-bus code, not final capture V4L2 pix
>> format.
> I just followed the existing code there, which already configures all
> of these.

Sorry never mind, I forgot that there is a need to check for planar formats
here.

>>>> Assuming that above does not work (and indeed parallel RGB565
>>>> must be handled as pass-through), then I think support for capturing
>>>> parallel RGB555 as pass-through should be added to this series as
>>>> well.
>>> I don't have a sensor which produces RGB555, so it wouldn't be able to
>>> test it.
>> Understood, but for code readability and consistency I think the code
>> can be cleaned up as above.
> Yes, i've changed that for v2.
>
>

The new macros can be used in more places. I will respond to v2 patch.

Steve