Commit 396369d6 authored by Igor Torrente's avatar Igor Torrente Committed by Melissa Wen
Browse files

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: default avatarMelissa Wen <mwen@igalia.com>
Signed-off-by: default avatarIgor Torrente <igormtorrente@gmail.com>
Signed-off-by: default avatarMelissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220905190811.25024-10-igormtorrente@gmail.com
parent 3675d8a1

drivers/gpu/drm/vkms/vkms_formats.c

+70 −0
Original line number Diff line number Diff line
@@ -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;

	}

drivers/gpu/drm/vkms/vkms_plane.c

+4 −2
Original line number Diff line number Diff line
@@ -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 *

drivers/gpu/drm/vkms/vkms_writeback.c

+2 −1
Original line number Diff line number Diff line
@@ -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 = {