[PATCH v4 9/9] drm: vkms: Add support to the RGB565 format
Melissa Wen
mwen at igalia.com
Tue Feb 8 10:50:07 UTC 2022
On 01/21, Igor Torrente wrote:
> Adds this common format to vkms.
>
> This commit also adds new helper macros to deal with fixed-point
> arithmetic.
>
> It was done to improve the precision of the conversion to ARGB16161616
> since the "conversion ratio" is not an integer.
>
> Signed-off-by: Igor Torrente <igormtorrente at gmail.com>
> ---
> V3: Adapt the handlers to the new format introduced in patch 7 V3.
> ---
> drivers/gpu/drm/vkms/vkms_formats.c | 74 +++++++++++++++++++++++++++
> drivers/gpu/drm/vkms/vkms_formats.h | 6 +++
> drivers/gpu/drm/vkms/vkms_plane.c | 6 ++-
> drivers/gpu/drm/vkms/vkms_writeback.c | 3 +-
> 4 files changed, 86 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
> index 661da39d1276..dc612882dd8c 100644
> --- a/drivers/gpu/drm/vkms/vkms_formats.c
> +++ b/drivers/gpu/drm/vkms/vkms_formats.c
> @@ -11,6 +11,8 @@ format_transform_func get_fmt_transform_function(u32 format)
> return &get_ARGB16161616;
> else if (format == DRM_FORMAT_XRGB16161616)
> return &XRGB16161616_to_ARGB16161616;
> + else if (format == DRM_FORMAT_RGB565)
> + return &RGB565_to_ARGB16161616;
> else
> return &XRGB8888_to_ARGB16161616;
> }
> @@ -23,6 +25,8 @@ format_transform_func get_wb_fmt_transform_function(u32 format)
> return &convert_to_ARGB16161616;
> else if (format == DRM_FORMAT_XRGB16161616)
> return &convert_to_XRGB16161616;
> + else if (format == DRM_FORMAT_RGB565)
> + return &convert_to_RGB565;
> else
> return &convert_to_XRGB8888;
> }
> @@ -33,6 +37,26 @@ static int pixel_offset(struct vkms_frame_info *frame_info, int x, int y)
> + (x * frame_info->cpp);
> }
>
> +/*
> + * FP stands for _Fixed Point_ and **not** _Float Point_
> + * LF stands for Long Float (i.e. double)
> + * The following macros help doing fixed point arithmetic.
> + */
> +/*
> + * With FP scale 15 we have 17 and 15 bits of integer and fractional parts
> + * respectively.
> + * | 0000 0000 0000 0000 0.000 0000 0000 0000 |
> + * 31 0
> + */
> +#define FP_SCALE 15
> +
> +#define LF_TO_FP(a) ((a) * (u64)(1 << FP_SCALE))
> +#define INT_TO_FP(a) ((a) << FP_SCALE)
> +#define FP_MUL(a, b) ((s32)(((s64)(a) * (b)) >> FP_SCALE))
> +#define FP_DIV(a, b) ((s32)(((s64)(a) << FP_SCALE) / (b)))
> +/* This macro converts a fixed point number to int, and round half up it */
> +#define FP_TO_INT_ROUND_UP(a) (((a) + (1 << (FP_SCALE - 1))) >> FP_SCALE)
> +
> /*
> * packed_pixels_addr - Get the pointer to pixel of a given pair of coordinates
> *
> @@ -125,6 +149,33 @@ void XRGB16161616_to_ARGB16161616(struct vkms_frame_info *frame_info, int y,
> }
> }
>
> +void RGB565_to_ARGB16161616(struct vkms_frame_info *frame_info, int y,
> + struct line_buffer *stage_buffer)
> +{
> + u16 *src_pixels = get_packed_src_addr(frame_info, y);
> + int x, x_limit = drm_rect_width(&frame_info->dst);
> +
> + for (x = 0; x < x_limit; x++, src_pixels++) {
> + u16 rgb_565 = le16_to_cpu(*src_pixels);
> + int fp_r = INT_TO_FP((rgb_565 >> 11) & 0x1f);
> + int fp_g = INT_TO_FP((rgb_565 >> 5) & 0x3f);
> + int fp_b = INT_TO_FP(rgb_565 & 0x1f);
> +
> + /*
> + * The magic constants is the "conversion ratio" and is calculated
> + * dividing 65535(2^16 - 1) by 31(2^5 -1) and 63(2^6 - 1)
> + * respectively.
> + */
> + int fp_rb_ratio = LF_TO_FP(2114.032258065);
> + int fp_g_ratio = LF_TO_FP(1040.238095238);
> +
> + stage_buffer[x].a = (u16)0xffff;
> + stage_buffer[x].r = FP_TO_INT_ROUND_UP(FP_MUL(fp_r, fp_rb_ratio));
> + stage_buffer[x].g = FP_TO_INT_ROUND_UP(FP_MUL(fp_g, fp_g_ratio));
> + stage_buffer[x].b = FP_TO_INT_ROUND_UP(FP_MUL(fp_b, fp_rb_ratio));
> + }
> +}
> +
I don't know if there is a testcase in IGT check this conversion, did
you use anyone here? Does it enables any other testcase?
Thanks,
Melissa
>
> /*
> * The following functions take an line of ARGB16161616 pixels from the
> @@ -203,3 +254,26 @@ void convert_to_XRGB16161616(struct vkms_frame_info *frame_info, int y,
> dst_pixels[0] = src_buffer[x].b;
> }
> }
> +
> +void convert_to_RGB565(struct vkms_frame_info *frame_info, int y,
> + struct line_buffer *src_buffer)
> +{
> + int x, x_dst = frame_info->dst.x1;
> + u16 *dst_pixels = packed_pixels_addr(frame_info, x_dst, y);
> + int x_limit = drm_rect_width(&frame_info->dst);
> +
> + for (x = 0; x < x_limit; x++, dst_pixels++) {
> + int fp_r = INT_TO_FP(src_buffer[x].r);
> + int fp_g = INT_TO_FP(src_buffer[x].g);
> + int fp_b = INT_TO_FP(src_buffer[x].b);
> +
> + int fp_rb_ratio = LF_TO_FP(2114.032258065);
> + int fp_g_ratio = LF_TO_FP(1040.238095238);
> +
> + u16 r = FP_TO_INT_ROUND_UP(FP_DIV(fp_r, fp_rb_ratio));
> + u16 g = FP_TO_INT_ROUND_UP(FP_DIV(fp_g, fp_g_ratio));
> + u16 b = FP_TO_INT_ROUND_UP(FP_DIV(fp_b, fp_rb_ratio));
> +
> + *dst_pixels = cpu_to_le16(r << 11 | g << 5 | b);
> + }
> +}
> diff --git a/drivers/gpu/drm/vkms/vkms_formats.h b/drivers/gpu/drm/vkms/vkms_formats.h
> index 22358f3a33ab..836d6e43ea90 100644
> --- a/drivers/gpu/drm/vkms/vkms_formats.h
> +++ b/drivers/gpu/drm/vkms/vkms_formats.h
> @@ -21,6 +21,9 @@ void get_ARGB16161616(struct vkms_frame_info *frame_info, int y,
> void XRGB16161616_to_ARGB16161616(struct vkms_frame_info *frame_info, int y,
> struct line_buffer *stage_buffer);
>
> +void RGB565_to_ARGB16161616(struct vkms_frame_info *frame_info, int y,
> + struct line_buffer *stage_buffer);
> +
> void convert_to_ARGB8888(struct vkms_frame_info *frame_info, int y,
> struct line_buffer *src_buffer);
>
> @@ -33,6 +36,9 @@ void convert_to_ARGB16161616(struct vkms_frame_info *frame_info, int y,
> void convert_to_XRGB16161616(struct vkms_frame_info *frame_info, int y,
> struct line_buffer *src_buffer);
>
> +void convert_to_RGB565(struct vkms_frame_info *frame_info, int y,
> + struct line_buffer *src_buffer);
> +
> typedef void (*format_transform_func)(struct vkms_frame_info *frame_info, int y,
> struct line_buffer *buffer);
>
> diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
> index 1d70c9e8f109..4643eefcdf29 100644
> --- a/drivers/gpu/drm/vkms/vkms_plane.c
> +++ b/drivers/gpu/drm/vkms/vkms_plane.c
> @@ -13,14 +13,16 @@
>
> static const u32 vkms_formats[] = {
> DRM_FORMAT_XRGB8888,
> - DRM_FORMAT_XRGB16161616
> + DRM_FORMAT_XRGB16161616,
> + DRM_FORMAT_RGB565
> };
>
> static const u32 vkms_plane_formats[] = {
> DRM_FORMAT_ARGB8888,
> DRM_FORMAT_XRGB8888,
> DRM_FORMAT_XRGB16161616,
> - DRM_FORMAT_ARGB16161616
> + DRM_FORMAT_ARGB16161616,
> + DRM_FORMAT_RGB565
> };
>
> static struct drm_plane_state *
> diff --git a/drivers/gpu/drm/vkms/vkms_writeback.c b/drivers/gpu/drm/vkms/vkms_writeback.c
> index 393d3fc7966f..1aaa630090d3 100644
> --- a/drivers/gpu/drm/vkms/vkms_writeback.c
> +++ b/drivers/gpu/drm/vkms/vkms_writeback.c
> @@ -15,7 +15,8 @@
> static const u32 vkms_wb_formats[] = {
> DRM_FORMAT_XRGB8888,
> DRM_FORMAT_XRGB16161616,
> - DRM_FORMAT_ARGB16161616
> + DRM_FORMAT_ARGB16161616,
> + DRM_FORMAT_RGB565
> };
>
> static const struct drm_connector_funcs vkms_wb_connector_funcs = {
> --
> 2.30.2
>
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