From 396369d6754993e40f1c84b2e22e40e92dfa4c49 Mon Sep 17 00:00:00 2001 From: Igor Torrente Date: Mon, 5 Sep 2022 16:08:11 -0300 Subject: [PATCH] drm: vkms: Add support to the RGB565 format 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. V3: Adapt the handlers to the new format introduced in patch 7 V3. V5: Minor improvements V6: Minor improvements (Pekka Paalanen) Reviewed-by: Melissa Wen Signed-off-by: Igor Torrente Signed-off-by: Melissa Wen Link: https://patchwork.freedesktop.org/patch/msgid/20220905190811.25024-10-igormtorrente@gmail.com --- drivers/gpu/drm/vkms/vkms_formats.c | 70 +++++++++++++++++++++++++++ drivers/gpu/drm/vkms/vkms_plane.c | 6 ++- drivers/gpu/drm/vkms/vkms_writeback.c | 3 +- 3 files changed, 76 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c index 3af36476a7df..300abb4d1dfe 100644 --- a/drivers/gpu/drm/vkms/vkms_formats.c +++ b/drivers/gpu/drm/vkms/vkms_formats.c @@ -5,6 +5,23 @@ #include "vkms_formats.h" +/* The following macros help doing fixed point arithmetic. */ +/* + * With Fixed-Point 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 SHIFT 15 + +#define INT_TO_FIXED(a) ((a) << SHIFT) +#define FIXED_MUL(a, b) ((s32)(((s64)(a) * (b)) >> SHIFT)) +#define FIXED_DIV(a, b) ((s32)(((s64)(a) << SHIFT) / (b))) +/* This macro converts a fixed point number to int, and round half up it */ +#define FIXED_TO_INT_ROUND(a) (((a) + (1 << (SHIFT - 1))) >> SHIFT) +#define INT_TO_FIXED_DIV(a, b) (FIXED_DIV(INT_TO_FIXED(a), INT_TO_FIXED(b))) +#define INT_TO_FIXED_DIV(a, b) (FIXED_DIV(INT_TO_FIXED(a), INT_TO_FIXED(b))) + static size_t pixel_offset(const struct vkms_frame_info *frame_info, int x, int y) { return frame_info->offset + (y * frame_info->pitch) @@ -112,6 +129,30 @@ static void XRGB16161616_to_argb_u16(struct line_buffer *stage_buffer, } } +static void RGB565_to_argb_u16(struct line_buffer *stage_buffer, + const struct vkms_frame_info *frame_info, int y) +{ + struct pixel_argb_u16 *out_pixels = stage_buffer->pixels; + u16 *src_pixels = get_packed_src_addr(frame_info, y); + int x_limit = min_t(size_t, drm_rect_width(&frame_info->dst), + stage_buffer->n_pixels); + + s32 fp_rb_ratio = INT_TO_FIXED_DIV(65535, 31); + s32 fp_g_ratio = INT_TO_FIXED_DIV(65535, 63); + + for (size_t x = 0; x < x_limit; x++, src_pixels++) { + u16 rgb_565 = le16_to_cpu(*src_pixels); + s32 fp_r = INT_TO_FIXED((rgb_565 >> 11) & 0x1f); + s32 fp_g = INT_TO_FIXED((rgb_565 >> 5) & 0x3f); + s32 fp_b = INT_TO_FIXED(rgb_565 & 0x1f); + + out_pixels[x].a = (u16)0xffff; + out_pixels[x].r = FIXED_TO_INT_ROUND(FIXED_MUL(fp_r, fp_rb_ratio)); + out_pixels[x].g = FIXED_TO_INT_ROUND(FIXED_MUL(fp_g, fp_g_ratio)); + out_pixels[x].b = FIXED_TO_INT_ROUND(FIXED_MUL(fp_b, fp_rb_ratio)); + } +} + /* * The following functions take an line of argb_u16 pixels from the * src_buffer, convert them to a specific format, and store them in the @@ -198,6 +239,31 @@ static void argb_u16_to_XRGB16161616(struct vkms_frame_info *frame_info, } } +static void argb_u16_to_RGB565(struct vkms_frame_info *frame_info, + const struct line_buffer *src_buffer, int y) +{ + int x_dst = frame_info->dst.x1; + u16 *dst_pixels = packed_pixels_addr(frame_info, x_dst, y); + struct pixel_argb_u16 *in_pixels = src_buffer->pixels; + int x_limit = min_t(size_t, drm_rect_width(&frame_info->dst), + src_buffer->n_pixels); + + s32 fp_rb_ratio = INT_TO_FIXED_DIV(65535, 31); + s32 fp_g_ratio = INT_TO_FIXED_DIV(65535, 63); + + for (size_t x = 0; x < x_limit; x++, dst_pixels++) { + s32 fp_r = INT_TO_FIXED(in_pixels[x].r); + s32 fp_g = INT_TO_FIXED(in_pixels[x].g); + s32 fp_b = INT_TO_FIXED(in_pixels[x].b); + + u16 r = FIXED_TO_INT_ROUND(FIXED_DIV(fp_r, fp_rb_ratio)); + u16 g = FIXED_TO_INT_ROUND(FIXED_DIV(fp_g, fp_g_ratio)); + u16 b = FIXED_TO_INT_ROUND(FIXED_DIV(fp_b, fp_rb_ratio)); + + *dst_pixels = cpu_to_le16(r << 11 | g << 5 | b); + } +} + void *get_frame_to_line_function(u32 format) { switch (format) { @@ -209,6 +275,8 @@ void *get_frame_to_line_function(u32 format) return &ARGB16161616_to_argb_u16; case DRM_FORMAT_XRGB16161616: return &XRGB16161616_to_argb_u16; + case DRM_FORMAT_RGB565: + return &RGB565_to_argb_u16; default: return NULL; } @@ -225,6 +293,8 @@ void *get_line_to_frame_function(u32 format) return &argb_u16_to_ARGB16161616; case DRM_FORMAT_XRGB16161616: return &argb_u16_to_XRGB16161616; + case DRM_FORMAT_RGB565: + return &argb_u16_to_RGB565; default: return NULL; } diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c index f823fe315de6..f4319066adcc 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 16feea884646..84a51cd281b9 100644 --- a/drivers/gpu/drm/vkms/vkms_writeback.c +++ b/drivers/gpu/drm/vkms/vkms_writeback.c @@ -17,7 +17,8 @@ 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 = {