1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2012 Red Hat 4 * 5 * based in parts on udlfb.c: 6 * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it> 7 * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com> 8 * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com> 9 10 */ 11 12 #include <linux/dma-buf.h> 13 14 #include <drm/drm_atomic_helper.h> 15 #include <drm/drm_crtc_helper.h> 16 #include <drm/drm_damage_helper.h> 17 #include <drm/drm_fourcc.h> 18 #include <drm/drm_gem_framebuffer_helper.h> 19 #include <drm/drm_gem_shmem_helper.h> 20 #include <drm/drm_modeset_helper_vtables.h> 21 #include <drm/drm_vblank.h> 22 23 #include "udl_drv.h" 24 25 #define UDL_COLOR_DEPTH_16BPP 0 26 27 /* 28 * All DisplayLink bulk operations start with 0xAF, followed by specific code 29 * All operations are written to buffers which then later get sent to device 30 */ 31 static char *udl_set_register(char *buf, u8 reg, u8 val) 32 { 33 *buf++ = 0xAF; 34 *buf++ = 0x20; 35 *buf++ = reg; 36 *buf++ = val; 37 return buf; 38 } 39 40 static char *udl_vidreg_lock(char *buf) 41 { 42 return udl_set_register(buf, 0xFF, 0x00); 43 } 44 45 static char *udl_vidreg_unlock(char *buf) 46 { 47 return udl_set_register(buf, 0xFF, 0xFF); 48 } 49 50 static char *udl_set_blank_mode(char *buf, u8 mode) 51 { 52 return udl_set_register(buf, UDL_REG_BLANK_MODE, mode); 53 } 54 55 static char *udl_set_color_depth(char *buf, u8 selection) 56 { 57 return udl_set_register(buf, 0x00, selection); 58 } 59 60 static char *udl_set_base16bpp(char *wrptr, u32 base) 61 { 62 /* the base pointer is 16 bits wide, 0x20 is hi byte. */ 63 wrptr = udl_set_register(wrptr, 0x20, base >> 16); 64 wrptr = udl_set_register(wrptr, 0x21, base >> 8); 65 return udl_set_register(wrptr, 0x22, base); 66 } 67 68 /* 69 * DisplayLink HW has separate 16bpp and 8bpp framebuffers. 70 * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer 71 */ 72 static char *udl_set_base8bpp(char *wrptr, u32 base) 73 { 74 wrptr = udl_set_register(wrptr, 0x26, base >> 16); 75 wrptr = udl_set_register(wrptr, 0x27, base >> 8); 76 return udl_set_register(wrptr, 0x28, base); 77 } 78 79 static char *udl_set_register_16(char *wrptr, u8 reg, u16 value) 80 { 81 wrptr = udl_set_register(wrptr, reg, value >> 8); 82 return udl_set_register(wrptr, reg+1, value); 83 } 84 85 /* 86 * This is kind of weird because the controller takes some 87 * register values in a different byte order than other registers. 88 */ 89 static char *udl_set_register_16be(char *wrptr, u8 reg, u16 value) 90 { 91 wrptr = udl_set_register(wrptr, reg, value); 92 return udl_set_register(wrptr, reg+1, value >> 8); 93 } 94 95 /* 96 * LFSR is linear feedback shift register. The reason we have this is 97 * because the display controller needs to minimize the clock depth of 98 * various counters used in the display path. So this code reverses the 99 * provided value into the lfsr16 value by counting backwards to get 100 * the value that needs to be set in the hardware comparator to get the 101 * same actual count. This makes sense once you read above a couple of 102 * times and think about it from a hardware perspective. 103 */ 104 static u16 udl_lfsr16(u16 actual_count) 105 { 106 u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */ 107 108 while (actual_count--) { 109 lv = ((lv << 1) | 110 (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1)) 111 & 0xFFFF; 112 } 113 114 return (u16) lv; 115 } 116 117 /* 118 * This does LFSR conversion on the value that is to be written. 119 * See LFSR explanation above for more detail. 120 */ 121 static char *udl_set_register_lfsr16(char *wrptr, u8 reg, u16 value) 122 { 123 return udl_set_register_16(wrptr, reg, udl_lfsr16(value)); 124 } 125 126 /* 127 * This takes a standard fbdev screeninfo struct and all of its monitor mode 128 * details and converts them into the DisplayLink equivalent register commands. 129 ERR(vreg(dev, 0x00, (color_depth == 16) ? 0 : 1)); 130 ERR(vreg_lfsr16(dev, 0x01, xDisplayStart)); 131 ERR(vreg_lfsr16(dev, 0x03, xDisplayEnd)); 132 ERR(vreg_lfsr16(dev, 0x05, yDisplayStart)); 133 ERR(vreg_lfsr16(dev, 0x07, yDisplayEnd)); 134 ERR(vreg_lfsr16(dev, 0x09, xEndCount)); 135 ERR(vreg_lfsr16(dev, 0x0B, hSyncStart)); 136 ERR(vreg_lfsr16(dev, 0x0D, hSyncEnd)); 137 ERR(vreg_big_endian(dev, 0x0F, hPixels)); 138 ERR(vreg_lfsr16(dev, 0x11, yEndCount)); 139 ERR(vreg_lfsr16(dev, 0x13, vSyncStart)); 140 ERR(vreg_lfsr16(dev, 0x15, vSyncEnd)); 141 ERR(vreg_big_endian(dev, 0x17, vPixels)); 142 ERR(vreg_little_endian(dev, 0x1B, pixelClock5KHz)); 143 144 ERR(vreg(dev, 0x1F, 0)); 145 146 ERR(vbuf(dev, WRITE_VIDREG_UNLOCK, DSIZEOF(WRITE_VIDREG_UNLOCK))); 147 */ 148 static char *udl_set_vid_cmds(char *wrptr, struct drm_display_mode *mode) 149 { 150 u16 xds, yds; 151 u16 xde, yde; 152 u16 yec; 153 154 /* x display start */ 155 xds = mode->crtc_htotal - mode->crtc_hsync_start; 156 wrptr = udl_set_register_lfsr16(wrptr, 0x01, xds); 157 /* x display end */ 158 xde = xds + mode->crtc_hdisplay; 159 wrptr = udl_set_register_lfsr16(wrptr, 0x03, xde); 160 161 /* y display start */ 162 yds = mode->crtc_vtotal - mode->crtc_vsync_start; 163 wrptr = udl_set_register_lfsr16(wrptr, 0x05, yds); 164 /* y display end */ 165 yde = yds + mode->crtc_vdisplay; 166 wrptr = udl_set_register_lfsr16(wrptr, 0x07, yde); 167 168 /* x end count is active + blanking - 1 */ 169 wrptr = udl_set_register_lfsr16(wrptr, 0x09, 170 mode->crtc_htotal - 1); 171 172 /* libdlo hardcodes hsync start to 1 */ 173 wrptr = udl_set_register_lfsr16(wrptr, 0x0B, 1); 174 175 /* hsync end is width of sync pulse + 1 */ 176 wrptr = udl_set_register_lfsr16(wrptr, 0x0D, 177 mode->crtc_hsync_end - mode->crtc_hsync_start + 1); 178 179 /* hpixels is active pixels */ 180 wrptr = udl_set_register_16(wrptr, 0x0F, mode->hdisplay); 181 182 /* yendcount is vertical active + vertical blanking */ 183 yec = mode->crtc_vtotal; 184 wrptr = udl_set_register_lfsr16(wrptr, 0x11, yec); 185 186 /* libdlo hardcodes vsync start to 0 */ 187 wrptr = udl_set_register_lfsr16(wrptr, 0x13, 0); 188 189 /* vsync end is width of vsync pulse */ 190 wrptr = udl_set_register_lfsr16(wrptr, 0x15, mode->crtc_vsync_end - mode->crtc_vsync_start); 191 192 /* vpixels is active pixels */ 193 wrptr = udl_set_register_16(wrptr, 0x17, mode->crtc_vdisplay); 194 195 wrptr = udl_set_register_16be(wrptr, 0x1B, 196 mode->clock / 5); 197 198 return wrptr; 199 } 200 201 static char *udl_dummy_render(char *wrptr) 202 { 203 *wrptr++ = 0xAF; 204 *wrptr++ = 0x6A; /* copy */ 205 *wrptr++ = 0x00; /* from addr */ 206 *wrptr++ = 0x00; 207 *wrptr++ = 0x00; 208 *wrptr++ = 0x01; /* one pixel */ 209 *wrptr++ = 0x00; /* to address */ 210 *wrptr++ = 0x00; 211 *wrptr++ = 0x00; 212 return wrptr; 213 } 214 215 static int udl_crtc_write_mode_to_hw(struct drm_crtc *crtc) 216 { 217 struct drm_device *dev = crtc->dev; 218 struct udl_device *udl = dev->dev_private; 219 struct urb *urb; 220 char *buf; 221 int retval; 222 223 if (udl->mode_buf_len == 0) { 224 DRM_ERROR("No mode set\n"); 225 return -EINVAL; 226 } 227 228 urb = udl_get_urb(dev); 229 if (!urb) 230 return -ENOMEM; 231 232 buf = (char *)urb->transfer_buffer; 233 234 memcpy(buf, udl->mode_buf, udl->mode_buf_len); 235 retval = udl_submit_urb(dev, urb, udl->mode_buf_len); 236 DRM_DEBUG("write mode info %d\n", udl->mode_buf_len); 237 return retval; 238 } 239 240 static long udl_log_cpp(unsigned int cpp) 241 { 242 if (WARN_ON(!is_power_of_2(cpp))) 243 return -EINVAL; 244 return __ffs(cpp); 245 } 246 247 static int udl_aligned_damage_clip(struct drm_rect *clip, int x, int y, 248 int width, int height) 249 { 250 int x1, x2; 251 252 if (WARN_ON_ONCE(x < 0) || 253 WARN_ON_ONCE(y < 0) || 254 WARN_ON_ONCE(width < 0) || 255 WARN_ON_ONCE(height < 0)) 256 return -EINVAL; 257 258 x1 = ALIGN_DOWN(x, sizeof(unsigned long)); 259 x2 = ALIGN(width + (x - x1), sizeof(unsigned long)) + x1; 260 261 clip->x1 = x1; 262 clip->y1 = y; 263 clip->x2 = x2; 264 clip->y2 = y + height; 265 266 return 0; 267 } 268 269 int udl_handle_damage(struct drm_framebuffer *fb, int x, int y, 270 int width, int height) 271 { 272 struct drm_device *dev = fb->dev; 273 struct dma_buf_attachment *import_attach = fb->obj[0]->import_attach; 274 int i, ret, tmp_ret; 275 char *cmd; 276 struct urb *urb; 277 struct drm_rect clip; 278 int log_bpp; 279 void *vaddr; 280 281 ret = udl_log_cpp(fb->format->cpp[0]); 282 if (ret < 0) 283 return ret; 284 log_bpp = ret; 285 286 ret = udl_aligned_damage_clip(&clip, x, y, width, height); 287 if (ret) 288 return ret; 289 else if ((clip.x2 > fb->width) || (clip.y2 > fb->height)) 290 return -EINVAL; 291 292 if (import_attach) { 293 ret = dma_buf_begin_cpu_access(import_attach->dmabuf, 294 DMA_FROM_DEVICE); 295 if (ret) 296 return ret; 297 } 298 299 vaddr = drm_gem_shmem_vmap(fb->obj[0]); 300 if (IS_ERR(vaddr)) { 301 DRM_ERROR("failed to vmap fb\n"); 302 goto out_dma_buf_end_cpu_access; 303 } 304 305 urb = udl_get_urb(dev); 306 if (!urb) 307 goto out_drm_gem_shmem_vunmap; 308 cmd = urb->transfer_buffer; 309 310 for (i = clip.y1; i < clip.y2; i++) { 311 const int line_offset = fb->pitches[0] * i; 312 const int byte_offset = line_offset + (clip.x1 << log_bpp); 313 const int dev_byte_offset = (fb->width * i + clip.x1) << log_bpp; 314 const int byte_width = (clip.x2 - clip.x1) << log_bpp; 315 ret = udl_render_hline(dev, log_bpp, &urb, (char *)vaddr, 316 &cmd, byte_offset, dev_byte_offset, 317 byte_width); 318 if (ret) 319 goto out_drm_gem_shmem_vunmap; 320 } 321 322 if (cmd > (char *)urb->transfer_buffer) { 323 /* Send partial buffer remaining before exiting */ 324 int len; 325 if (cmd < (char *)urb->transfer_buffer + urb->transfer_buffer_length) 326 *cmd++ = 0xAF; 327 len = cmd - (char *)urb->transfer_buffer; 328 ret = udl_submit_urb(dev, urb, len); 329 } else { 330 udl_urb_completion(urb); 331 } 332 333 ret = 0; 334 335 out_drm_gem_shmem_vunmap: 336 drm_gem_shmem_vunmap(fb->obj[0], vaddr); 337 out_dma_buf_end_cpu_access: 338 if (import_attach) { 339 tmp_ret = dma_buf_end_cpu_access(import_attach->dmabuf, 340 DMA_FROM_DEVICE); 341 if (tmp_ret && !ret) 342 ret = tmp_ret; /* only update ret if not set yet */ 343 } 344 345 return ret; 346 } 347 348 /* 349 * Simple display pipeline 350 */ 351 352 static const uint32_t udl_simple_display_pipe_formats[] = { 353 DRM_FORMAT_RGB565, 354 DRM_FORMAT_XRGB8888, 355 }; 356 357 static enum drm_mode_status 358 udl_simple_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe, 359 const struct drm_display_mode *mode) 360 { 361 return MODE_OK; 362 } 363 364 static void 365 udl_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe, 366 struct drm_crtc_state *crtc_state, 367 struct drm_plane_state *plane_state) 368 { 369 struct drm_crtc *crtc = &pipe->crtc; 370 struct drm_device *dev = crtc->dev; 371 struct drm_framebuffer *fb = plane_state->fb; 372 struct udl_device *udl = dev->dev_private; 373 struct drm_display_mode *mode = &crtc_state->mode; 374 char *buf; 375 char *wrptr; 376 int color_depth = UDL_COLOR_DEPTH_16BPP; 377 378 crtc_state->no_vblank = true; 379 380 buf = (char *)udl->mode_buf; 381 382 /* This first section has to do with setting the base address on the 383 * controller associated with the display. There are 2 base 384 * pointers, currently, we only use the 16 bpp segment. 385 */ 386 wrptr = udl_vidreg_lock(buf); 387 wrptr = udl_set_color_depth(wrptr, color_depth); 388 /* set base for 16bpp segment to 0 */ 389 wrptr = udl_set_base16bpp(wrptr, 0); 390 /* set base for 8bpp segment to end of fb */ 391 wrptr = udl_set_base8bpp(wrptr, 2 * mode->vdisplay * mode->hdisplay); 392 393 wrptr = udl_set_vid_cmds(wrptr, mode); 394 wrptr = udl_set_blank_mode(wrptr, UDL_BLANK_MODE_ON); 395 wrptr = udl_vidreg_unlock(wrptr); 396 397 wrptr = udl_dummy_render(wrptr); 398 399 udl->mode_buf_len = wrptr - buf; 400 401 udl_handle_damage(fb, 0, 0, fb->width, fb->height); 402 403 if (!crtc_state->mode_changed) 404 return; 405 406 /* enable display */ 407 udl_crtc_write_mode_to_hw(crtc); 408 } 409 410 static void 411 udl_simple_display_pipe_disable(struct drm_simple_display_pipe *pipe) 412 { 413 struct drm_crtc *crtc = &pipe->crtc; 414 struct drm_device *dev = crtc->dev; 415 struct urb *urb; 416 char *buf; 417 418 urb = udl_get_urb(dev); 419 if (!urb) 420 return; 421 422 buf = (char *)urb->transfer_buffer; 423 buf = udl_vidreg_lock(buf); 424 buf = udl_set_blank_mode(buf, UDL_BLANK_MODE_POWERDOWN); 425 buf = udl_vidreg_unlock(buf); 426 buf = udl_dummy_render(buf); 427 428 udl_submit_urb(dev, urb, buf - (char *)urb->transfer_buffer); 429 } 430 431 static int 432 udl_simple_display_pipe_check(struct drm_simple_display_pipe *pipe, 433 struct drm_plane_state *plane_state, 434 struct drm_crtc_state *crtc_state) 435 { 436 return 0; 437 } 438 439 static void 440 udl_simple_display_pipe_update(struct drm_simple_display_pipe *pipe, 441 struct drm_plane_state *old_plane_state) 442 { 443 struct drm_plane_state *state = pipe->plane.state; 444 struct drm_framebuffer *fb = state->fb; 445 struct drm_rect rect; 446 447 if (!fb) 448 return; 449 450 if (drm_atomic_helper_damage_merged(old_plane_state, state, &rect)) 451 udl_handle_damage(fb, rect.x1, rect.y1, rect.x2 - rect.x1, 452 rect.y2 - rect.y1); 453 } 454 455 static const 456 struct drm_simple_display_pipe_funcs udl_simple_display_pipe_funcs = { 457 .mode_valid = udl_simple_display_pipe_mode_valid, 458 .enable = udl_simple_display_pipe_enable, 459 .disable = udl_simple_display_pipe_disable, 460 .check = udl_simple_display_pipe_check, 461 .update = udl_simple_display_pipe_update, 462 .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb, 463 }; 464 465 /* 466 * Modesetting 467 */ 468 469 static const struct drm_mode_config_funcs udl_mode_funcs = { 470 .fb_create = drm_gem_fb_create_with_dirty, 471 .atomic_check = drm_atomic_helper_check, 472 .atomic_commit = drm_atomic_helper_commit, 473 }; 474 475 int udl_modeset_init(struct drm_device *dev) 476 { 477 size_t format_count = ARRAY_SIZE(udl_simple_display_pipe_formats); 478 struct udl_device *udl = dev->dev_private; 479 struct drm_connector *connector; 480 int ret; 481 482 drm_mode_config_init(dev); 483 484 dev->mode_config.min_width = 640; 485 dev->mode_config.min_height = 480; 486 487 dev->mode_config.max_width = 2048; 488 dev->mode_config.max_height = 2048; 489 490 dev->mode_config.prefer_shadow = 0; 491 dev->mode_config.preferred_depth = 16; 492 493 dev->mode_config.funcs = &udl_mode_funcs; 494 495 connector = udl_connector_init(dev); 496 if (IS_ERR(connector)) { 497 ret = PTR_ERR(connector); 498 goto err_drm_mode_config_cleanup; 499 } 500 501 format_count = ARRAY_SIZE(udl_simple_display_pipe_formats); 502 503 ret = drm_simple_display_pipe_init(dev, &udl->display_pipe, 504 &udl_simple_display_pipe_funcs, 505 udl_simple_display_pipe_formats, 506 format_count, NULL, connector); 507 if (ret) 508 goto err_drm_mode_config_cleanup; 509 510 drm_mode_config_reset(dev); 511 512 return 0; 513 514 err_drm_mode_config_cleanup: 515 drm_mode_config_cleanup(dev); 516 return ret; 517 } 518 519 void udl_modeset_cleanup(struct drm_device *dev) 520 { 521 drm_mode_config_cleanup(dev); 522 } 523