From: Sven Püschel Date: Wed, 20 May 2026 22:44:10 +0000 (+0200) Subject: media: v4l2-common: add v4l2_fill_pixfmt_mp_aligned helper X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=2c225846271fc6b4f7e2a34271ebe828ed461772;p=thirdparty%2Flinux.git media: v4l2-common: add v4l2_fill_pixfmt_mp_aligned helper 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 Signed-off-by: Sven Püschel Signed-off-by: Nicolas Dufresne Signed-off-by: Hans Verkuil --- diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c index 3cc8b04e1ea6..65db7340ad38 100644 --- a/drivers/media/v4l2-core/v4l2-common.c +++ b/drivers/media/v4l2-core/v4l2-common.c @@ -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); diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h index 401d8506c24b..edd416178c33 100644 --- a/include/media/v4l2-common.h +++ b/include/media/v4l2-common.h @@ -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