Re: [PATCH v5 11/16] drm/vkms: Add YUV support

[Randy Dunlap <rdunlap@infradead.org>]

Hi,

On 3/13/24 10:45, Louis Chauvet wrote:
> From: Arthur Grillo <arthurgrillo@riseup.net>
> 

> 
> Signed-off-by: Arthur Grillo <arthurgrillo@riseup.net>
> [Louis Chauvet:
> - Adapted Arthur's work
> - Implemented the read_line_t callbacks for yuv
> - add struct conversion_matrix
> - remove struct pixel_yuv_u8
> - update the commit message
> - Merge the modifications from Arthur]
> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> ---
>  drivers/gpu/drm/vkms/vkms_drv.h     |  22 ++
>  drivers/gpu/drm/vkms/vkms_formats.c | 431 ++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/vkms/vkms_formats.h |   4 +
>  drivers/gpu/drm/vkms/vkms_plane.c   |  17 +-
>  4 files changed, 473 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
> index 23e1d247468d..f3116084de5a 100644
> --- a/drivers/gpu/drm/vkms/vkms_drv.h
> +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> @@ -99,6 +99,27 @@ typedef void (*pixel_read_line_t)(const struct vkms_plane_state *plane, int x_st
>  				  int y_start, enum pixel_read_direction direction, int count,
>  				  struct pixel_argb_u16 out_pixel[]);
>  
> +/**
> + * CONVERSION_MATRIX_FLOAT_DEPTH - Number of digits after the point for conversion matrix values

This should be

+ * define CONVERSION_MATRIX_FLOAT_DEPTH - Number of digits after the point for conversion matrix values

to conform to kernel-doc format.

> + */
> +#define CONVERSION_MATRIX_FLOAT_DEPTH 32
> +

> diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
> index 1449a0e6c706..edbf4b321b91 100644
> --- a/drivers/gpu/drm/vkms/vkms_formats.c
> +++ b/drivers/gpu/drm/vkms/vkms_formats.c

> +/**
> + * get_conversion_matrix_to_argb_u16() - Retrieve the correct yuv to rgb conversion matrix for a
> + * given encoding and range.
> + *
> + * If the matrix is not found, return a null pointer. In all other cases, it return a simple
> + * diagonal matrix, which act as a "no-op".
> + *
> + * @format: DRM_FORMAT_* value for which to obtain a conversion function (see [drm_fourcc.h])
> + * @encoding: DRM_COLOR_* value for which to obtain a conversion matrix
> + * @range: DRM_COLOR_*_RANGE value for which to obtain a conversion matrix
> + */
> +struct conversion_matrix *
> +get_conversion_matrix_to_argb_u16(u32 format, enum drm_color_encoding encoding,
> +				  enum drm_color_range range)
> +{
> +	static struct conversion_matrix no_operation = {
> +		.matrix = {
> +			{ 4294967296, 0,          0, },
> +			{ 0,          4294967296, 0, },
> +			{ 0,          0,          4294967296, },
> +		},
> +		.y_offset = 0,
> +	};
> +
> +	/*
> +	 * Those matrixies were generated using the colour python framework

	         matrices

> +	 *
> +	 * Below are the function calls used to generate eac matrix, go to

	                                                 each

> +	 * https://colour.readthedocs.io/en/develop/generated/colour.matrix_YCbCr.html
> +	 * for more info:
> +	 *
> +	 * numpy.around(colour.matrix_YCbCr(K=colour.WEIGHTS_YCBCR["ITU-R BT.601"],
> +	 *                                  is_legal = False,
> +	 *                                  bits = 8) * 2**32).astype(int)
> +	 */

> +
>  /**

Please convert this comment to kernel-doc format or just use "/*" to begin
the comment.

>   * Retrieve the correct write_pixel function for a specific format.
>   * If the format is not supported by VKMS a warn is emitted and a dummy "don't do anything"

> diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
> index 8875bed76410..987dd2b686a8 100644
> --- a/drivers/gpu/drm/vkms/vkms_plane.c
> +++ b/drivers/gpu/drm/vkms/vkms_plane.c


thanks.
-- 
#Randy