drivers/gpu/drm/vkms/vkms_formats.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2
   3 #include <linux/kernel.h>
   4 #include <linux/minmax.h>
   5
   6 #include <drm/drm_blend.h>
   7 #include <drm/drm_rect.h>
   8 #include <drm/drm_fixed.h>
   9
  10 #include "vkms_formats.h"
  11
  12 static size_t pixel_offset(const struct vkms_frame_info *frame_info, int x, int y)
  13 {
  14         return frame_info->offset + (y * frame_info->pitch)
  15                                   + (x * frame_info->cpp);
  16 }
  17
  18 /*
  19  * packed_pixels_addr - Get the pointer to pixel of a given pair of coordinates
  20  *
  21  * @frame_info: Buffer metadata
  22  * @x: The x(width) coordinate of the 2D buffer
  23  * @y: The y(Heigth) coordinate of the 2D buffer
  24  *
  25  * Takes the information stored in the frame_info, a pair of coordinates, and
  26  * returns the address of the first color channel.
  27  * This function assumes the channels are packed together, i.e. a color channel
  28  * comes immediately after another in the memory. And therefore, this function
  29  * doesn't work for YUV with chroma subsampling (e.g. YUV420 and NV21).
  30  */
  31 static void *packed_pixels_addr(const struct vkms_frame_info *frame_info,
  32                                 int x, int y)
  33 {
  34         size_t offset = pixel_offset(frame_info, x, y);
  35
  36         return (u8 *)frame_info->map[0].vaddr + offset;
  37 }
  38
  39 static void *get_packed_src_addr(const struct vkms_frame_info *frame_info, int y)
  40 {
  41         int x_src = frame_info->src.x1 >> 16;
  42         int y_src = y - frame_info->rotated.y1 + (frame_info->src.y1 >> 16);
  43
  44         return packed_pixels_addr(frame_info, x_src, y_src);
  45 }
  46
  47 static int get_x_position(const struct vkms_frame_info *frame_info, int limit, int x)
  48 {
  49         if (frame_info->rotation & (DRM_MODE_REFLECT_X | DRM_MODE_ROTATE_270))
  50                 return limit - x - 1;
  51         return x;
  52 }
  53
  54 static void ARGB8888_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
  55 {
  56         /*
  57          * The 257 is the "conversion ratio". This number is obtained by the
  58          * (2^16 - 1) / (2^8 - 1) division. Which, in this case, tries to get
  59          * the best color value in a pixel format with more possibilities.
  60          * A similar idea applies to others RGB color conversions.
  61          */
  62         out_pixel->a = (u16)src_pixels[3] * 257;
  63         out_pixel->r = (u16)src_pixels[2] * 257;
  64         out_pixel->g = (u16)src_pixels[1] * 257;
  65         out_pixel->b = (u16)src_pixels[0] * 257;
  66 }
  67
  68 static void XRGB8888_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
  69 {
  70         out_pixel->a = (u16)0xffff;
  71         out_pixel->r = (u16)src_pixels[2] * 257;
  72         out_pixel->g = (u16)src_pixels[1] * 257;
  73         out_pixel->b = (u16)src_pixels[0] * 257;
  74 }
  75
  76 static void ARGB16161616_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
  77 {
  78         u16 *pixels = (u16 *)src_pixels;
  79
  80         out_pixel->a = le16_to_cpu(pixels[3]);
  81         out_pixel->r = le16_to_cpu(pixels[2]);
  82         out_pixel->g = le16_to_cpu(pixels[1]);
  83         out_pixel->b = le16_to_cpu(pixels[0]);
  84 }
  85
  86 static void XRGB16161616_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
  87 {
  88         u16 *pixels = (u16 *)src_pixels;
  89
  90         out_pixel->a = (u16)0xffff;
  91         out_pixel->r = le16_to_cpu(pixels[2]);
  92         out_pixel->g = le16_to_cpu(pixels[1]);
  93         out_pixel->b = le16_to_cpu(pixels[0]);
  94 }
  95
  96 static void RGB565_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
  97 {
  98         u16 *pixels = (u16 *)src_pixels;
  99
 100         s64 fp_rb_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(31));
 101         s64 fp_g_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(63));
 102
 103         u16 rgb_565 = le16_to_cpu(*pixels);
 104         s64 fp_r = drm_int2fixp((rgb_565 >> 11) & 0x1f);
 105         s64 fp_g = drm_int2fixp((rgb_565 >> 5) & 0x3f);
 106         s64 fp_b = drm_int2fixp(rgb_565 & 0x1f);
 107
 108         out_pixel->a = (u16)0xffff;
 109         out_pixel->r = drm_fixp2int(drm_fixp_mul(fp_r, fp_rb_ratio));
 110         out_pixel->g = drm_fixp2int(drm_fixp_mul(fp_g, fp_g_ratio));
 111         out_pixel->b = drm_fixp2int(drm_fixp_mul(fp_b, fp_rb_ratio));
 112 }
 113
 114 void vkms_compose_row(struct line_buffer *stage_buffer, struct vkms_plane_state *plane, int y)
 115 {
 116         struct pixel_argb_u16 *out_pixels = stage_buffer->pixels;
 117         struct vkms_frame_info *frame_info = plane->frame_info;
 118         u8 *src_pixels = get_packed_src_addr(frame_info, y);
 119         int limit = min_t(size_t, drm_rect_width(&frame_info->dst), stage_buffer->n_pixels);
 120
 121         for (size_t x = 0; x < limit; x++, src_pixels += frame_info->cpp) {
 122                 int x_pos = get_x_position(frame_info, limit, x);
 123
 124                 if (drm_rotation_90_or_270(frame_info->rotation))
 125                         src_pixels = get_packed_src_addr(frame_info, x + frame_info->rotated.y1)
 126                                 + frame_info->cpp * y;
 127
 128                 plane->pixel_read(src_pixels, &out_pixels[x_pos]);
 129         }
 130 }
 131
 132 /*
 133  * The following  functions take an line of argb_u16 pixels from the
 134  * src_buffer, convert them to a specific format, and store them in the
 135  * destination.
 136  *
 137  * They are used in the `compose_active_planes` to convert and store a line
 138  * from the src_buffer to the writeback buffer.
 139  */
 140 static void argb_u16_to_ARGB8888(struct vkms_frame_info *frame_info,
 141                                  const struct line_buffer *src_buffer, int y)
 142 {
 143         int x_dst = frame_info->dst.x1;
 144         u8 *dst_pixels = packed_pixels_addr(frame_info, x_dst, y);
 145         struct pixel_argb_u16 *in_pixels = src_buffer->pixels;
 146         int x_limit = min_t(size_t, drm_rect_width(&frame_info->dst),
 147                             src_buffer->n_pixels);
 148
 149         for (size_t x = 0; x < x_limit; x++, dst_pixels += 4) {
 150                 /*
 151                  * This sequence below is important because the format's byte order is
 152                  * in little-endian. In the case of the ARGB8888 the memory is
 153                  * organized this way:
 154                  *
 155                  * | Addr     | = blue channel
 156                  * | Addr + 1 | = green channel
 157                  * | Addr + 2 | = Red channel
 158                  * | Addr + 3 | = Alpha channel
 159                  */
 160                 dst_pixels[3] = DIV_ROUND_CLOSEST(in_pixels[x].a, 257);
 161                 dst_pixels[2] = DIV_ROUND_CLOSEST(in_pixels[x].r, 257);
 162                 dst_pixels[1] = DIV_ROUND_CLOSEST(in_pixels[x].g, 257);
 163                 dst_pixels[0] = DIV_ROUND_CLOSEST(in_pixels[x].b, 257);
 164         }
 165 }
 166
 167 static void argb_u16_to_XRGB8888(struct vkms_frame_info *frame_info,
 168                                  const struct line_buffer *src_buffer, int y)
 169 {
 170         int x_dst = frame_info->dst.x1;
 171         u8 *dst_pixels = packed_pixels_addr(frame_info, x_dst, y);
 172         struct pixel_argb_u16 *in_pixels = src_buffer->pixels;
 173         int x_limit = min_t(size_t, drm_rect_width(&frame_info->dst),
 174                             src_buffer->n_pixels);
 175
 176         for (size_t x = 0; x < x_limit; x++, dst_pixels += 4) {
 177                 dst_pixels[3] = 0xff;
 178                 dst_pixels[2] = DIV_ROUND_CLOSEST(in_pixels[x].r, 257);
 179                 dst_pixels[1] = DIV_ROUND_CLOSEST(in_pixels[x].g, 257);
 180                 dst_pixels[0] = DIV_ROUND_CLOSEST(in_pixels[x].b, 257);
 181         }
 182 }
 183
 184 static void argb_u16_to_ARGB16161616(struct vkms_frame_info *frame_info,
 185                                      const struct line_buffer *src_buffer, int y)
 186 {
 187         int x_dst = frame_info->dst.x1;
 188         u16 *dst_pixels = packed_pixels_addr(frame_info, x_dst, y);
 189         struct pixel_argb_u16 *in_pixels = src_buffer->pixels;
 190         int x_limit = min_t(size_t, drm_rect_width(&frame_info->dst),
 191                             src_buffer->n_pixels);
 192
 193         for (size_t x = 0; x < x_limit; x++, dst_pixels += 4) {
 194                 dst_pixels[3] = cpu_to_le16(in_pixels[x].a);
 195                 dst_pixels[2] = cpu_to_le16(in_pixels[x].r);
 196                 dst_pixels[1] = cpu_to_le16(in_pixels[x].g);
 197                 dst_pixels[0] = cpu_to_le16(in_pixels[x].b);
 198         }
 199 }
 200
 201 static void argb_u16_to_XRGB16161616(struct vkms_frame_info *frame_info,
 202                                      const struct line_buffer *src_buffer, int y)
 203 {
 204         int x_dst = frame_info->dst.x1;
 205         u16 *dst_pixels = packed_pixels_addr(frame_info, x_dst, y);
 206         struct pixel_argb_u16 *in_pixels = src_buffer->pixels;
 207         int x_limit = min_t(size_t, drm_rect_width(&frame_info->dst),
 208                             src_buffer->n_pixels);
 209
 210         for (size_t x = 0; x < x_limit; x++, dst_pixels += 4) {
 211                 dst_pixels[3] = 0xffff;
 212                 dst_pixels[2] = cpu_to_le16(in_pixels[x].r);
 213                 dst_pixels[1] = cpu_to_le16(in_pixels[x].g);
 214                 dst_pixels[0] = cpu_to_le16(in_pixels[x].b);
 215         }
 216 }
 217
 218 static void argb_u16_to_RGB565(struct vkms_frame_info *frame_info,
 219                                const struct line_buffer *src_buffer, int y)
 220 {
 221         int x_dst = frame_info->dst.x1;
 222         u16 *dst_pixels = packed_pixels_addr(frame_info, x_dst, y);
 223         struct pixel_argb_u16 *in_pixels = src_buffer->pixels;
 224         int x_limit = min_t(size_t, drm_rect_width(&frame_info->dst),
 225                             src_buffer->n_pixels);
 226
 227         s64 fp_rb_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(31));
 228         s64 fp_g_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(63));
 229
 230         for (size_t x = 0; x < x_limit; x++, dst_pixels++) {
 231                 s64 fp_r = drm_int2fixp(in_pixels[x].r);
 232                 s64 fp_g = drm_int2fixp(in_pixels[x].g);
 233                 s64 fp_b = drm_int2fixp(in_pixels[x].b);
 234
 235                 u16 r = drm_fixp2int(drm_fixp_div(fp_r, fp_rb_ratio));
 236                 u16 g = drm_fixp2int(drm_fixp_div(fp_g, fp_g_ratio));
 237                 u16 b = drm_fixp2int(drm_fixp_div(fp_b, fp_rb_ratio));
 238
 239                 *dst_pixels = cpu_to_le16(r << 11 | g << 5 | b);
 240         }
 241 }
 242
 243 void *get_pixel_conversion_function(u32 format)
 244 {
 245         switch (format) {
 246         case DRM_FORMAT_ARGB8888:
 247                 return &ARGB8888_to_argb_u16;
 248         case DRM_FORMAT_XRGB8888:
 249                 return &XRGB8888_to_argb_u16;
 250         case DRM_FORMAT_ARGB16161616:
 251                 return &ARGB16161616_to_argb_u16;
 252         case DRM_FORMAT_XRGB16161616:
 253                 return &XRGB16161616_to_argb_u16;
 254         case DRM_FORMAT_RGB565:
 255                 return &RGB565_to_argb_u16;
 256         default:
 257                 return NULL;
 258         }
 259 }
 260
 261 void *get_line_to_frame_function(u32 format)
 262 {
 263         switch (format) {
 264         case DRM_FORMAT_ARGB8888:
 265                 return &argb_u16_to_ARGB8888;
 266         case DRM_FORMAT_XRGB8888:
 267                 return &argb_u16_to_XRGB8888;
 268         case DRM_FORMAT_ARGB16161616:
 269                 return &argb_u16_to_ARGB16161616;
 270         case DRM_FORMAT_XRGB16161616:
 271                 return &argb_u16_to_XRGB16161616;
 272         case DRM_FORMAT_RGB565:
 273                 return &argb_u16_to_RGB565;
 274         default:
 275                 return NULL;
 276         }
 277 }