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media: v4l2-common: add v4l2_fill_pixfmt_mp_aligned helper

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Add a v4l2_fill_pixfmt_mp_aligned helper which allows the user to
specify a custom stride alignment in bytes. This is necessary for
hardware like the Rockchip RGA3, which requires the stride value to be
aligned to a 16 bytes boundary.

The code makes some assumptions about the v4l2 format to simplify the
calculation. They currently hold for all known v4l2 formats.

v4l2_format_plane_stride uses an unsigned int as argument type to avoid
the later multiplication from overflowing the u8 value. All other places
use u8, as no practical use cases for a larger alignment are known at
the moment.

Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Sven Püschel <s.pueschel@pengutronix.de>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
This commit is contained in:
Sven Püschel 2026-05-21 00:44:10 +02:00 committed by Hans Verkuil
parent 84fbe791a6
commit 2c22584627
2 changed files with 48 additions and 12 deletions
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56
drivers/media/v4l2-core/v4l2-common.c
View File

@ -432,14 +432,33 @@ static inline unsigned int v4l2_format_block_height(const struct v4l2_format_inf
}
static inline unsigned int v4l2_format_plane_stride(const struct v4l2_format_info *info, int plane,
unsigned int width)
unsigned int width, unsigned int byte_alignment)
{
unsigned int hdiv = plane ? info->hdiv : 1;
unsigned int aligned_width =
ALIGN(width, v4l2_format_block_width(info, plane));
return DIV_ROUND_UP(aligned_width, hdiv) *
info->bpp[plane] / info->bpp_div[plane];
/*
* Formats with a single memory plane derive the stride of the
* other planes from the y stride. To avoid hardware or software
* deriving a different stride for the composite plane,
* multiply the alignment accordingly.
*
* It assumes the following format properties:
* - bpp_div[0] == bpp_div[1]
* - The multiplication factor doesn't differ between the non y planes
* - The multiplication factor is a power of 2
*/
if (info->mem_planes == 1 && info->comp_planes > 1) {
if (plane == 0)
byte_alignment *= DIV_ROUND_UP(info->hdiv * info->bpp[0], info->bpp[1]);
else
byte_alignment *= DIV_ROUND_UP(info->bpp[1], info->hdiv * info->bpp[0]);
}
return ALIGN(DIV_ROUND_UP(aligned_width, hdiv) * info->bpp[plane] /
info->bpp_div[plane],
byte_alignment);
}
static inline unsigned int v4l2_format_plane_height(const struct v4l2_format_info *info, int plane,
@ -453,9 +472,10 @@ static inline unsigned int v4l2_format_plane_height(const struct v4l2_format_inf
}
static inline unsigned int v4l2_format_plane_size(const struct v4l2_format_info *info, int plane,
unsigned int width, unsigned int height)
unsigned int width, unsigned int height,
u8 stride_alignment)
{
return v4l2_format_plane_stride(info, plane, width) *
return v4l2_format_plane_stride(info, plane, width, stride_alignment) *
v4l2_format_plane_height(info, plane, height);
}
@ -476,8 +496,9 @@ void v4l2_apply_frmsize_constraints(u32 *width, u32 *height,
}
EXPORT_SYMBOL_GPL(v4l2_apply_frmsize_constraints);
int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt,
u32 pixelformat, u32 width, u32 height)
int v4l2_fill_pixfmt_mp_aligned(struct v4l2_pix_format_mplane *pixfmt,
u32 pixelformat, u32 width, u32 height,
u8 stride_alignment)
{
const struct v4l2_format_info *info;
struct v4l2_plane_pix_format *plane;
@ -494,23 +515,34 @@ int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt,
if (info->mem_planes == 1) {
plane = &pixfmt->plane_fmt[0];
plane->bytesperline = v4l2_format_plane_stride(info, 0, width);
plane->bytesperline = v4l2_format_plane_stride(info, 0, width,
stride_alignment);
plane->sizeimage = 0;
for (i = 0; i < info->comp_planes; i++)
plane->sizeimage +=
v4l2_format_plane_size(info, i, width, height);
v4l2_format_plane_size(info, i, width, height,
stride_alignment);
} else {
for (i = 0; i < info->comp_planes; i++) {
plane = &pixfmt->plane_fmt[i];
plane->bytesperline =
v4l2_format_plane_stride(info, i, width);
v4l2_format_plane_stride(info, i, width,
stride_alignment);
plane->sizeimage = plane->bytesperline *
v4l2_format_plane_height(info, i, height);
}
}
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt_mp_aligned);
int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt,
u32 pixelformat, u32 width, u32 height)
{
return v4l2_fill_pixfmt_mp_aligned(pixfmt, pixelformat,
width, height, 1);
}
EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt_mp);
int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
@ -530,12 +562,12 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
pixfmt->width = width;
pixfmt->height = height;
pixfmt->pixelformat = pixelformat;
pixfmt->bytesperline = v4l2_format_plane_stride(info, 0, width);
pixfmt->bytesperline = v4l2_format_plane_stride(info, 0, width, 1);
pixfmt->sizeimage = 0;
for (i = 0; i < info->comp_planes; i++)
pixfmt->sizeimage +=
v4l2_format_plane_size(info, i, width, height);
v4l2_format_plane_size(info, i, width, height, 1);
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt);

4
include/media/v4l2-common.h
View File

@ -558,6 +558,10 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
u32 width, u32 height);
int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt, u32 pixelformat,
u32 width, u32 height);
/* @stride_alignment is a power of 2 value in bytes */
int v4l2_fill_pixfmt_mp_aligned(struct v4l2_pix_format_mplane *pixfmt,
u32 pixelformat, u32 width, u32 height,
u8 stride_alignment);
/**
* v4l2_get_link_freq - Get link rate from transmitter