Re: [RFC PATCH] media: staging: ipu3-imgu: add the AWB memory layout

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hello,

(CC'ing Tomasz)

Gentle ping.

On Wed, Sep 01, 2021 at 12:34:00AM +0300, Laurent Pinchart wrote:
> On Tue, Aug 31, 2021 at 08:51:40PM +0200, Jean-Michel Hautbois wrote:
> > While parsing the RAW AWB metadata, the AWB layout was missing to fully
> > understand which byte corresponds to which feature. Make the field names
> > and usage explicit, as it is used by the userspace applications.
> > 
> > Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
> > ---
> > This structure layout is defined in CrOs:
> > https://chromium.googlesource.com/chromiumos/platform/arc-camera/+/refs/heads/master/hal/intel/include/ia_imaging/awb_public.h
> > 
> > There are a few things not really understood right now:
> > - Is sat_ratio a full scale ratio (I can't get more than some values out
> >   of it, is it a ratio of 25%, 50%, 75%, 100% ?)
> > - What are the real minimum and maximum values for the grid size ? From
> >   CrOs it appears to be [16, 80] for width and [16, 60] for height while
> >   in this file it seems to be [16, 160] for width and not really defined
> >   for height AFAICT ?
> > - Same for the block_width_log2 and block_height_log2 which are [3, 7]
> >   in this file and [3, 6] in the awb_public.h header ?
> > 
> >  .../media/ipu3/include/uapi/intel-ipu3.h      | 38 ++++++++++++++-----
> >  1 file changed, 29 insertions(+), 9 deletions(-)
> > 
> > diff --git a/drivers/staging/media/ipu3/include/uapi/intel-ipu3.h b/drivers/staging/media/ipu3/include/uapi/intel-ipu3.h
> > index fa3d6ee5adf2..83191aff2ddd 100644
> > --- a/drivers/staging/media/ipu3/include/uapi/intel-ipu3.h
> > +++ b/drivers/staging/media/ipu3/include/uapi/intel-ipu3.h
> > @@ -61,20 +61,40 @@ struct ipu3_uapi_grid_config {
> >  	__u16 y_end;
> >  } __packed;
> >  
> > +/**
> > + * struct ipu3_uapi_awb_raw_buffer - Memory layout for each cell in AWB
> > + *
> > + * @Gr_avg:	Green average for red lines in the cell.
> > + * @R_avg:	Red average in the cell.
> > + * @B_avg:	Blue average in the cell.
> > + * @Gb_avg:	Green average for blue lines in the cell.
> > + * @sat_ratio:  Saturation ratio in the cell.
> > + * @padding0:   Unused byte for padding.
> > + * @padding1:   Unused byte for padding.
> > + * @padding2:   Unused byte for padding.
> > + */
> > +struct ipu3_uapi_awb_raw_buffer {
> > +    unsigned char Gr_avg;
> > +    unsigned char R_avg;
> > +    unsigned char B_avg;
> > +    unsigned char Gb_avg;
> > +    unsigned char sat_ratio;
> > +    unsigned char padding0;
> > +    unsigned char padding1;
> > +    unsigned char padding2;
> > +} __packed;
> > +
> >  /*
> >   * The grid based data is divided into "slices" called set, each slice of setX
> >   * refers to ipu3_uapi_grid_config width * height_per_slice.
> >   */
> >  #define IPU3_UAPI_AWB_MAX_SETS				60
> > -/* Based on grid size 80 * 60 and cell size 16 x 16 */
> > -#define IPU3_UAPI_AWB_SET_SIZE				1280
> > -#define IPU3_UAPI_AWB_MD_ITEM_SIZE			8
> > -#define IPU3_UAPI_AWB_SPARE_FOR_BUBBLES \
> > -	(IPU3_UAPI_MAX_BUBBLE_SIZE * IPU3_UAPI_MAX_STRIPES * \
> > -	 IPU3_UAPI_AWB_MD_ITEM_SIZE)
> > +#define AWB_PUBLIC_NUM_OF_ITEMS_IN_SET			160
> > +/* Based on max grid height + Spare for bubbles */
> > +#define AWB_PUBLIC_NUM_OF_SETS_IN_BUFFER IPU3_UAPI_AWB_MAX_SETS + \
> > +	(IPU3_UAPI_MAX_BUBBLE_SIZE * IPU3_UAPI_MAX_STRIPES)
> >  #define IPU3_UAPI_AWB_MAX_BUFFER_SIZE \
> > -	(IPU3_UAPI_AWB_MAX_SETS * \
> > -	 (IPU3_UAPI_AWB_SET_SIZE + IPU3_UAPI_AWB_SPARE_FOR_BUBBLES))
> > +        AWB_PUBLIC_NUM_OF_SETS_IN_BUFFER * AWB_PUBLIC_NUM_OF_ITEMS_IN_SET
> >  
> >  /**
> >   * struct ipu3_uapi_awb_raw_buffer - AWB raw buffer
> > @@ -83,7 +103,7 @@ struct ipu3_uapi_grid_config {
> >   *		the average values for each color channel.
> >   */
> >  struct ipu3_uapi_awb_raw_buffer {
> > -	__u8 meta_data[IPU3_UAPI_AWB_MAX_BUFFER_SIZE]
> > +	struct ipu3_uapi_awb_raw_buffer meta_data[IPU3_UAPI_AWB_MAX_BUFFER_SIZE]
> >  		__attribute__((aligned(32)));
> >  } __packed;
> >  

-- 
Regards,

Laurent Pinchart