linux/drivers/gpu/drm/vkms/vkms_formats.c

// SPDX-License-Identifier: GPL-2.0+

#include <linux/kernel.h>
#include <linux/minmax.h>

#include <drm/drm_blend.h>
#include <drm/drm_rect.h>
#include <drm/drm_fixed.h>

#include "vkms_formats.h"

static size_t pixel_offset(const struct vkms_frame_info *frame_info, int x, int y)
{ … }

/*
 * packed_pixels_addr - Get the pointer to pixel of a given pair of coordinates
 *
 * @frame_info: Buffer metadata
 * @x: The x(width) coordinate of the 2D buffer
 * @y: The y(Heigth) coordinate of the 2D buffer
 *
 * Takes the information stored in the frame_info, a pair of coordinates, and
 * returns the address of the first color channel.
 * This function assumes the channels are packed together, i.e. a color channel
 * comes immediately after another in the memory. And therefore, this function
 * doesn't work for YUV with chroma subsampling (e.g. YUV420 and NV21).
 */
static void *packed_pixels_addr(const struct vkms_frame_info *frame_info,
				int x, int y)
{ … }

static void *get_packed_src_addr(const struct vkms_frame_info *frame_info, int y)
{ … }

static int get_x_position(const struct vkms_frame_info *frame_info, int limit, int x)
{ … }

static void ARGB8888_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
{ … }

static void XRGB8888_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
{ … }

static void ARGB16161616_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
{ … }

static void XRGB16161616_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
{ … }

static void RGB565_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
{ … }

/**
 * vkms_compose_row - compose a single row of a plane
 * @stage_buffer: output line with the composed pixels
 * @plane: state of the plane that is being composed
 * @y: y coordinate of the row
 *
 * This function composes a single row of a plane. It gets the source pixels
 * through the y coordinate (see get_packed_src_addr()) and goes linearly
 * through the source pixel, reading the pixels and converting it to
 * ARGB16161616 (see the pixel_read() callback). For rotate-90 and rotate-270,
 * the source pixels are not traversed linearly. The source pixels are queried
 * on each iteration in order to traverse the pixels vertically.
 */
void vkms_compose_row(struct line_buffer *stage_buffer, struct vkms_plane_state *plane, int y)
{ … }

/*
 * 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
 * destination.
 *
 * They are used in the `compose_active_planes` to convert and store a line
 * from the src_buffer to the writeback buffer.
 */
static void argb_u16_to_ARGB8888(u8 *dst_pixels, struct pixel_argb_u16 *in_pixel)
{ … }

static void argb_u16_to_XRGB8888(u8 *dst_pixels, struct pixel_argb_u16 *in_pixel)
{ … }

static void argb_u16_to_ARGB16161616(u8 *dst_pixels, struct pixel_argb_u16 *in_pixel)
{ … }

static void argb_u16_to_XRGB16161616(u8 *dst_pixels, struct pixel_argb_u16 *in_pixel)
{ … }

static void argb_u16_to_RGB565(u8 *dst_pixels, struct pixel_argb_u16 *in_pixel)
{ … }

void vkms_writeback_row(struct vkms_writeback_job *wb,
			const struct line_buffer *src_buffer, int y)
{ … }

void *get_pixel_conversion_function(u32 format)
{ … }

void *get_pixel_write_function(u32 format)
{ … }