[RESEND v6 9/9] drm: vkms: Add support to the RGB565 format
Igor Torrente
igormtorrente at gmail.com
Fri Aug 19 18:24:11 UTC 2022
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)
Signed-off-by: Igor Torrente <igormtorrente at 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 8b651ffcc743..3f6a3cdb81e5 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
@@ -199,6 +240,31 @@ 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);
+ }
+}
+
frame_to_line_func get_frame_to_line_function(u32 format)
{
switch (format) {
@@ -210,6 +276,8 @@ frame_to_line_func 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;
}
@@ -226,6 +294,8 @@ line_to_frame_func 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 0e33e3471d40..53646ccf141b 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -14,14 +14,16 @@
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 c417f94be2a2..c6e4f3d7aa0d 100644
--- a/drivers/gpu/drm/vkms/vkms_writeback.c
+++ b/drivers/gpu/drm/vkms/vkms_writeback.c
@@ -16,7 +16,8 @@
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
More information about the dri-devel
mailing list