drivers/gpu/drm/sun4i/sun4i_backend.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2015 Free Electrons
   4  * Copyright (C) 2015 NextThing Co
   5  *
   6  * Maxime Ripard <maxime.ripard@free-electrons.com>
   7  */
   8
   9 #include <linux/component.h>
  10 #include <linux/list.h>
  11 #include <linux/module.h>
  12 #include <linux/of_device.h>
  13 #include <linux/of_graph.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/reset.h>
  17
  18 #include <drm/drm_atomic.h>
  19 #include <drm/drm_atomic_helper.h>
  20 #include <drm/drm_blend.h>
  21 #include <drm/drm_crtc.h>
  22 #include <drm/drm_fb_dma_helper.h>
  23 #include <drm/drm_fourcc.h>
  24 #include <drm/drm_framebuffer.h>
  25 #include <drm/drm_gem_dma_helper.h>
  26 #include <drm/drm_probe_helper.h>
  27
  28 #include "sun4i_backend.h"
  29 #include "sun4i_drv.h"
  30 #include "sun4i_frontend.h"
  31 #include "sun4i_layer.h"
  32 #include "sunxi_engine.h"
  33
  34 struct sun4i_backend_quirks {
  35         /* backend <-> TCON muxing selection done in backend */
  36         bool needs_output_muxing;
  37
  38         /* alpha at the lowest z position is not always supported */
  39         bool supports_lowest_plane_alpha;
  40 };
  41
  42 static const u32 sunxi_rgb2yuv_coef[12] = {
  43         0x00000107, 0x00000204, 0x00000064, 0x00000108,
  44         0x00003f69, 0x00003ed6, 0x000001c1, 0x00000808,
  45         0x000001c1, 0x00003e88, 0x00003fb8, 0x00000808
  46 };
  47
  48 static void sun4i_backend_apply_color_correction(struct sunxi_engine *engine)
  49 {
  50         int i;
  51
  52         DRM_DEBUG_DRIVER("Applying RGB to YUV color correction\n");
  53
  54         /* Set color correction */
  55         regmap_write(engine->regs, SUN4I_BACKEND_OCCTL_REG,
  56                      SUN4I_BACKEND_OCCTL_ENABLE);
  57
  58         for (i = 0; i < 12; i++)
  59                 regmap_write(engine->regs, SUN4I_BACKEND_OCRCOEF_REG(i),
  60                              sunxi_rgb2yuv_coef[i]);
  61 }
  62
  63 static void sun4i_backend_disable_color_correction(struct sunxi_engine *engine)
  64 {
  65         DRM_DEBUG_DRIVER("Disabling color correction\n");
  66
  67         /* Disable color correction */
  68         regmap_update_bits(engine->regs, SUN4I_BACKEND_OCCTL_REG,
  69                            SUN4I_BACKEND_OCCTL_ENABLE, 0);
  70 }
  71
  72 static void sun4i_backend_commit(struct sunxi_engine *engine,
  73                                  struct drm_crtc *crtc,
  74                                  struct drm_atomic_state *state)
  75 {
  76         DRM_DEBUG_DRIVER("Committing changes\n");
  77
  78         regmap_write(engine->regs, SUN4I_BACKEND_REGBUFFCTL_REG,
  79                      SUN4I_BACKEND_REGBUFFCTL_AUTOLOAD_DIS |
  80                      SUN4I_BACKEND_REGBUFFCTL_LOADCTL);
  81 }
  82
  83 void sun4i_backend_layer_enable(struct sun4i_backend *backend,
  84                                 int layer, bool enable)
  85 {
  86         u32 val;
  87
  88         DRM_DEBUG_DRIVER("%sabling layer %d\n", enable ? "En" : "Dis",
  89                          layer);
  90
  91         if (enable)
  92                 val = SUN4I_BACKEND_MODCTL_LAY_EN(layer);
  93         else
  94                 val = 0;
  95
  96         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
  97                            SUN4I_BACKEND_MODCTL_LAY_EN(layer), val);
  98 }
  99
 100 static int sun4i_backend_drm_format_to_layer(u32 format, u32 *mode)
 101 {
 102         switch (format) {
 103         case DRM_FORMAT_ARGB8888:
 104                 *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB8888;
 105                 break;
 106
 107         case DRM_FORMAT_ARGB4444:
 108                 *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB4444;
 109                 break;
 110
 111         case DRM_FORMAT_ARGB1555:
 112                 *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB1555;
 113                 break;
 114
 115         case DRM_FORMAT_RGBA5551:
 116                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGBA5551;
 117                 break;
 118
 119         case DRM_FORMAT_RGBA4444:
 120                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGBA4444;
 121                 break;
 122
 123         case DRM_FORMAT_XRGB8888:
 124                 *mode = SUN4I_BACKEND_LAY_FBFMT_XRGB8888;
 125                 break;
 126
 127         case DRM_FORMAT_RGB888:
 128                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGB888;
 129                 break;
 130
 131         case DRM_FORMAT_RGB565:
 132                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGB565;
 133                 break;
 134
 135         default:
 136                 return -EINVAL;
 137         }
 138
 139         return 0;
 140 }
 141
 142 static const uint32_t sun4i_backend_formats[] = {
 143         DRM_FORMAT_ARGB1555,
 144         DRM_FORMAT_ARGB4444,
 145         DRM_FORMAT_ARGB8888,
 146         DRM_FORMAT_RGB565,
 147         DRM_FORMAT_RGB888,
 148         DRM_FORMAT_RGBA4444,
 149         DRM_FORMAT_RGBA5551,
 150         DRM_FORMAT_UYVY,
 151         DRM_FORMAT_VYUY,
 152         DRM_FORMAT_XRGB8888,
 153         DRM_FORMAT_YUYV,
 154         DRM_FORMAT_YVYU,
 155 };
 156
 157 bool sun4i_backend_format_is_supported(uint32_t fmt, uint64_t modifier)
 158 {
 159         unsigned int i;
 160
 161         if (modifier != DRM_FORMAT_MOD_LINEAR)
 162                 return false;
 163
 164         for (i = 0; i < ARRAY_SIZE(sun4i_backend_formats); i++)
 165                 if (sun4i_backend_formats[i] == fmt)
 166                         return true;
 167
 168         return false;
 169 }
 170
 171 int sun4i_backend_update_layer_coord(struct sun4i_backend *backend,
 172                                      int layer, struct drm_plane *plane)
 173 {
 174         struct drm_plane_state *state = plane->state;
 175
 176         DRM_DEBUG_DRIVER("Updating layer %d\n", layer);
 177
 178         /* Set height and width */
 179         DRM_DEBUG_DRIVER("Layer size W: %u H: %u\n",
 180                          state->crtc_w, state->crtc_h);
 181         regmap_write(backend->engine.regs, SUN4I_BACKEND_LAYSIZE_REG(layer),
 182                      SUN4I_BACKEND_LAYSIZE(state->crtc_w,
 183                                            state->crtc_h));
 184
 185         /* Set base coordinates */
 186         DRM_DEBUG_DRIVER("Layer coordinates X: %d Y: %d\n",
 187                          state->crtc_x, state->crtc_y);
 188         regmap_write(backend->engine.regs, SUN4I_BACKEND_LAYCOOR_REG(layer),
 189                      SUN4I_BACKEND_LAYCOOR(state->crtc_x,
 190                                            state->crtc_y));
 191
 192         return 0;
 193 }
 194
 195 static int sun4i_backend_update_yuv_format(struct sun4i_backend *backend,
 196                                            int layer, struct drm_plane *plane)
 197 {
 198         struct drm_plane_state *state = plane->state;
 199         struct drm_framebuffer *fb = state->fb;
 200         const struct drm_format_info *format = fb->format;
 201         const uint32_t fmt = format->format;
 202         u32 val = SUN4I_BACKEND_IYUVCTL_EN;
 203         int i;
 204
 205         for (i = 0; i < ARRAY_SIZE(sunxi_bt601_yuv2rgb_coef); i++)
 206                 regmap_write(backend->engine.regs,
 207                              SUN4I_BACKEND_YGCOEF_REG(i),
 208                              sunxi_bt601_yuv2rgb_coef[i]);
 209
 210         /*
 211          * We should do that only for a single plane, but the
 212          * framebuffer's atomic_check has our back on this.
 213          */
 214         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
 215                            SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN,
 216                            SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN);
 217
 218         /* TODO: Add support for the multi-planar YUV formats */
 219         if (drm_format_info_is_yuv_packed(format) &&
 220             drm_format_info_is_yuv_sampling_422(format))
 221                 val |= SUN4I_BACKEND_IYUVCTL_FBFMT_PACKED_YUV422;
 222         else
 223                 DRM_DEBUG_DRIVER("Unsupported YUV format (0x%x)\n", fmt);
 224
 225         /*
 226          * Allwinner seems to list the pixel sequence from right to left, while
 227          * DRM lists it from left to right.
 228          */
 229         switch (fmt) {
 230         case DRM_FORMAT_YUYV:
 231                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_VYUY;
 232                 break;
 233         case DRM_FORMAT_YVYU:
 234                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_UYVY;
 235                 break;
 236         case DRM_FORMAT_UYVY:
 237                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_YVYU;
 238                 break;
 239         case DRM_FORMAT_VYUY:
 240                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_YUYV;
 241                 break;
 242         default:
 243                 DRM_DEBUG_DRIVER("Unsupported YUV pixel sequence (0x%x)\n",
 244                                  fmt);
 245         }
 246
 247         regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVCTL_REG, val);
 248
 249         return 0;
 250 }
 251
 252 int sun4i_backend_update_layer_formats(struct sun4i_backend *backend,
 253                                        int layer, struct drm_plane *plane)
 254 {
 255         struct drm_plane_state *state = plane->state;
 256         struct drm_framebuffer *fb = state->fb;
 257         u32 val;
 258         int ret;
 259
 260         /* Clear the YUV mode */
 261         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
 262                            SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN, 0);
 263
 264         val = SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA(state->alpha >> 8);
 265         if (state->alpha != DRM_BLEND_ALPHA_OPAQUE)
 266                 val |= SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_EN;
 267         regmap_update_bits(backend->engine.regs,
 268                            SUN4I_BACKEND_ATTCTL_REG0(layer),
 269                            SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_MASK |
 270                            SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_EN,
 271                            val);
 272
 273         if (fb->format->is_yuv)
 274                 return sun4i_backend_update_yuv_format(backend, layer, plane);
 275
 276         ret = sun4i_backend_drm_format_to_layer(fb->format->format, &val);
 277         if (ret) {
 278                 DRM_DEBUG_DRIVER("Invalid format\n");
 279                 return ret;
 280         }
 281
 282         regmap_update_bits(backend->engine.regs,
 283                            SUN4I_BACKEND_ATTCTL_REG1(layer),
 284                            SUN4I_BACKEND_ATTCTL_REG1_LAY_FBFMT, val);
 285
 286         return 0;
 287 }
 288
 289 int sun4i_backend_update_layer_frontend(struct sun4i_backend *backend,
 290                                         int layer, uint32_t fmt)
 291 {
 292         u32 val;
 293         int ret;
 294
 295         ret = sun4i_backend_drm_format_to_layer(fmt, &val);
 296         if (ret) {
 297                 DRM_DEBUG_DRIVER("Invalid format\n");
 298                 return ret;
 299         }
 300
 301         regmap_update_bits(backend->engine.regs,
 302                            SUN4I_BACKEND_ATTCTL_REG0(layer),
 303                            SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN,
 304                            SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN);
 305
 306         regmap_update_bits(backend->engine.regs,
 307                            SUN4I_BACKEND_ATTCTL_REG1(layer),
 308                            SUN4I_BACKEND_ATTCTL_REG1_LAY_FBFMT, val);
 309
 310         return 0;
 311 }
 312
 313 static int sun4i_backend_update_yuv_buffer(struct sun4i_backend *backend,
 314                                            struct drm_framebuffer *fb,
 315                                            dma_addr_t paddr)
 316 {
 317         /* TODO: Add support for the multi-planar YUV formats */
 318         DRM_DEBUG_DRIVER("Setting packed YUV buffer address to %pad\n", &paddr);
 319         regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVADD_REG(0), paddr);
 320
 321         DRM_DEBUG_DRIVER("Layer line width: %d bits\n", fb->pitches[0] * 8);
 322         regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVLINEWIDTH_REG(0),
 323                      fb->pitches[0] * 8);
 324
 325         return 0;
 326 }
 327
 328 int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend,
 329                                       int layer, struct drm_plane *plane)
 330 {
 331         struct drm_plane_state *state = plane->state;
 332         struct drm_framebuffer *fb = state->fb;
 333         u32 lo_paddr, hi_paddr;
 334         dma_addr_t dma_addr;
 335
 336         /* Set the line width */
 337         DRM_DEBUG_DRIVER("Layer line width: %d bits\n", fb->pitches[0] * 8);
 338         regmap_write(backend->engine.regs,
 339                      SUN4I_BACKEND_LAYLINEWIDTH_REG(layer),
 340                      fb->pitches[0] * 8);
 341
 342         /* Get the start of the displayed memory */
 343         dma_addr = drm_fb_dma_get_gem_addr(fb, state, 0);
 344         DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &dma_addr);
 345
 346         if (fb->format->is_yuv)
 347                 return sun4i_backend_update_yuv_buffer(backend, fb, dma_addr);
 348
 349         /* Write the 32 lower bits of the address (in bits) */
 350         lo_paddr = dma_addr << 3;
 351         DRM_DEBUG_DRIVER("Setting address lower bits to 0x%x\n", lo_paddr);
 352         regmap_write(backend->engine.regs,
 353                      SUN4I_BACKEND_LAYFB_L32ADD_REG(layer),
 354                      lo_paddr);
 355
 356         /* And the upper bits */
 357         hi_paddr = dma_addr >> 29;
 358         DRM_DEBUG_DRIVER("Setting address high bits to 0x%x\n", hi_paddr);
 359         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_LAYFB_H4ADD_REG,
 360                            SUN4I_BACKEND_LAYFB_H4ADD_MSK(layer),
 361                            SUN4I_BACKEND_LAYFB_H4ADD(layer, hi_paddr));
 362
 363         return 0;
 364 }
 365
 366 int sun4i_backend_update_layer_zpos(struct sun4i_backend *backend, int layer,
 367                                     struct drm_plane *plane)
 368 {
 369         struct drm_plane_state *state = plane->state;
 370         struct sun4i_layer_state *p_state = state_to_sun4i_layer_state(state);
 371         unsigned int priority = state->normalized_zpos;
 372         unsigned int pipe = p_state->pipe;
 373
 374         DRM_DEBUG_DRIVER("Setting layer %d's priority to %d and pipe %d\n",
 375                          layer, priority, pipe);
 376         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
 377                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL_MASK |
 378                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PRISEL_MASK,
 379                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL(p_state->pipe) |
 380                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PRISEL(priority));
 381
 382         return 0;
 383 }
 384
 385 void sun4i_backend_cleanup_layer(struct sun4i_backend *backend,
 386                                  int layer)
 387 {
 388         regmap_update_bits(backend->engine.regs,
 389                            SUN4I_BACKEND_ATTCTL_REG0(layer),
 390                            SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN |
 391                            SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN, 0);
 392 }
 393
 394 static bool sun4i_backend_plane_uses_scaler(struct drm_plane_state *state)
 395 {
 396         u16 src_h = state->src_h >> 16;
 397         u16 src_w = state->src_w >> 16;
 398
 399         DRM_DEBUG_DRIVER("Input size %dx%d, output size %dx%d\n",
 400                          src_w, src_h, state->crtc_w, state->crtc_h);
 401
 402         if ((state->crtc_h != src_h) || (state->crtc_w != src_w))
 403                 return true;
 404
 405         return false;
 406 }
 407
 408 static bool sun4i_backend_plane_uses_frontend(struct drm_plane_state *state)
 409 {
 410         struct sun4i_layer *layer = plane_to_sun4i_layer(state->plane);
 411         struct sun4i_backend *backend = layer->backend;
 412         uint32_t format = state->fb->format->format;
 413         uint64_t modifier = state->fb->modifier;
 414
 415         if (IS_ERR(backend->frontend))
 416                 return false;
 417
 418         if (!sun4i_frontend_format_is_supported(format, modifier))
 419                 return false;
 420
 421         if (!sun4i_backend_format_is_supported(format, modifier))
 422                 return true;
 423
 424         /*
 425          * TODO: The backend alone allows 2x and 4x integer scaling, including
 426          * support for an alpha component (which the frontend doesn't support).
 427          * Use the backend directly instead of the frontend in this case, with
 428          * another test to return false.
 429          */
 430
 431         if (sun4i_backend_plane_uses_scaler(state))
 432                 return true;
 433
 434         /*
 435          * Here the format is supported by both the frontend and the backend
 436          * and no frontend scaling is required, so use the backend directly.
 437          */
 438         return false;
 439 }
 440
 441 static bool sun4i_backend_plane_is_supported(struct drm_plane_state *state,
 442                                              bool *uses_frontend)
 443 {
 444         if (sun4i_backend_plane_uses_frontend(state)) {
 445                 *uses_frontend = true;
 446                 return true;
 447         }
 448
 449         *uses_frontend = false;
 450
 451         /* Scaling is not supported without the frontend. */
 452         if (sun4i_backend_plane_uses_scaler(state))
 453                 return false;
 454
 455         return true;
 456 }
 457
 458 static void sun4i_backend_atomic_begin(struct sunxi_engine *engine,
 459                                        struct drm_crtc_state *old_state)
 460 {
 461         u32 val;
 462
 463         WARN_ON(regmap_read_poll_timeout(engine->regs,
 464                                          SUN4I_BACKEND_REGBUFFCTL_REG,
 465                                          val, !(val & SUN4I_BACKEND_REGBUFFCTL_LOADCTL),
 466                                          100, 50000));
 467 }
 468
 469 static int sun4i_backend_atomic_check(struct sunxi_engine *engine,
 470                                       struct drm_crtc_state *crtc_state)
 471 {
 472         struct drm_plane_state *plane_states[SUN4I_BACKEND_NUM_LAYERS] = { 0 };
 473         struct sun4i_backend *backend = engine_to_sun4i_backend(engine);
 474         struct drm_atomic_state *state = crtc_state->state;
 475         struct drm_device *drm = state->dev;
 476         struct drm_plane *plane;
 477         unsigned int num_planes = 0;
 478         unsigned int num_alpha_planes = 0;
 479         unsigned int num_frontend_planes = 0;
 480         unsigned int num_alpha_planes_max = 1;
 481         unsigned int num_yuv_planes = 0;
 482         unsigned int current_pipe = 0;
 483         unsigned int i;
 484
 485         DRM_DEBUG_DRIVER("Starting checking our planes\n");
 486
 487         if (!crtc_state->planes_changed)
 488                 return 0;
 489
 490         drm_for_each_plane_mask(plane, drm, crtc_state->plane_mask) {
 491                 struct drm_plane_state *plane_state =
 492                         drm_atomic_get_plane_state(state, plane);
 493                 struct sun4i_layer_state *layer_state =
 494                         state_to_sun4i_layer_state(plane_state);
 495                 struct drm_framebuffer *fb = plane_state->fb;
 496
 497                 if (!sun4i_backend_plane_is_supported(plane_state,
 498                                                       &layer_state->uses_frontend))
 499                         return -EINVAL;
 500
 501                 if (layer_state->uses_frontend) {
 502                         DRM_DEBUG_DRIVER("Using the frontend for plane %d\n",
 503                                          plane->index);
 504                         num_frontend_planes++;
 505                 } else {
 506                         if (fb->format->is_yuv) {
 507                                 DRM_DEBUG_DRIVER("Plane FB format is YUV\n");
 508                                 num_yuv_planes++;
 509                         }
 510                 }
 511
 512                 DRM_DEBUG_DRIVER("Plane FB format is %p4cc\n",
 513                                  &fb->format->format);
 514                 if (fb->format->has_alpha || (plane_state->alpha != DRM_BLEND_ALPHA_OPAQUE))
 515                         num_alpha_planes++;
 516
 517                 DRM_DEBUG_DRIVER("Plane zpos is %d\n",
 518                                  plane_state->normalized_zpos);
 519
 520                 /* Sort our planes by Zpos */
 521                 plane_states[plane_state->normalized_zpos] = plane_state;
 522
 523                 num_planes++;
 524         }
 525
 526         /* All our planes were disabled, bail out */
 527         if (!num_planes)
 528                 return 0;
 529
 530         /*
 531          * The hardware is a bit unusual here.
 532          *
 533          * Even though it supports 4 layers, it does the composition
 534          * in two separate steps.
 535          *
 536          * The first one is assigning a layer to one of its two
 537          * pipes. If more that 1 layer is assigned to the same pipe,
 538          * and if pixels overlaps, the pipe will take the pixel from
 539          * the layer with the highest priority.
 540          *
 541          * The second step is the actual alpha blending, that takes
 542          * the two pipes as input, and uses the potential alpha
 543          * component to do the transparency between the two.
 544          *
 545          * This two-step scenario makes us unable to guarantee a
 546          * robust alpha blending between the 4 layers in all
 547          * situations, since this means that we need to have one layer
 548          * with alpha at the lowest position of our two pipes.
 549          *
 550          * However, we cannot even do that on every platform, since
 551          * the hardware has a bug where the lowest plane of the lowest
 552          * pipe (pipe 0, priority 0), if it has any alpha, will
 553          * discard the pixel data entirely and just display the pixels
 554          * in the background color (black by default).
 555          *
 556          * This means that on the affected platforms, we effectively
 557          * have only three valid configurations with alpha, all of
 558          * them with the alpha being on pipe1 with the lowest
 559          * position, which can be 1, 2 or 3 depending on the number of
 560          * planes and their zpos.
 561          */
 562
 563         /* For platforms that are not affected by the issue described above. */
 564         if (backend->quirks->supports_lowest_plane_alpha)
 565                 num_alpha_planes_max++;
 566
 567         if (num_alpha_planes > num_alpha_planes_max) {
 568                 DRM_DEBUG_DRIVER("Too many planes with alpha, rejecting...\n");
 569                 return -EINVAL;
 570         }
 571
 572         /* We can't have an alpha plane at the lowest position */
 573         if (!backend->quirks->supports_lowest_plane_alpha &&
 574             (plane_states[0]->alpha != DRM_BLEND_ALPHA_OPAQUE))
 575                 return -EINVAL;
 576
 577         for (i = 1; i < num_planes; i++) {
 578                 struct drm_plane_state *p_state = plane_states[i];
 579                 struct drm_framebuffer *fb = p_state->fb;
 580                 struct sun4i_layer_state *s_state = state_to_sun4i_layer_state(p_state);
 581
 582                 /*
 583                  * The only alpha position is the lowest plane of the
 584                  * second pipe.
 585                  */
 586                 if (fb->format->has_alpha || (p_state->alpha != DRM_BLEND_ALPHA_OPAQUE))
 587                         current_pipe++;
 588
 589                 s_state->pipe = current_pipe;
 590         }
 591
 592         /* We can only have a single YUV plane at a time */
 593         if (num_yuv_planes > SUN4I_BACKEND_NUM_YUV_PLANES) {
 594                 DRM_DEBUG_DRIVER("Too many planes with YUV, rejecting...\n");
 595                 return -EINVAL;
 596         }
 597
 598         if (num_frontend_planes > SUN4I_BACKEND_NUM_FRONTEND_LAYERS) {
 599                 DRM_DEBUG_DRIVER("Too many planes going through the frontend, rejecting\n");
 600                 return -EINVAL;
 601         }
 602
 603         DRM_DEBUG_DRIVER("State valid with %u planes, %u alpha, %u video, %u YUV\n",
 604                          num_planes, num_alpha_planes, num_frontend_planes,
 605                          num_yuv_planes);
 606
 607         return 0;
 608 }
 609
 610 static void sun4i_backend_vblank_quirk(struct sunxi_engine *engine)
 611 {
 612         struct sun4i_backend *backend = engine_to_sun4i_backend(engine);
 613         struct sun4i_frontend *frontend = backend->frontend;
 614
 615         if (!frontend)
 616                 return;
 617
 618         /*
 619          * In a teardown scenario with the frontend involved, we have
 620          * to keep the frontend enabled until the next vblank, and
 621          * only then disable it.
 622          *
 623          * This is due to the fact that the backend will not take into
 624          * account the new configuration (with the plane that used to
 625          * be fed by the frontend now disabled) until we write to the
 626          * commit bit and the hardware fetches the new configuration
 627          * during the next vblank.
 628          *
 629          * So we keep the frontend around in order to prevent any
 630          * visual artifacts.
 631          */
 632         spin_lock(&backend->frontend_lock);
 633         if (backend->frontend_teardown) {
 634                 sun4i_frontend_exit(frontend);
 635                 backend->frontend_teardown = false;
 636         }
 637         spin_unlock(&backend->frontend_lock);
 638 };
 639
 640 static void sun4i_backend_mode_set(struct sunxi_engine *engine,
 641                                    const struct drm_display_mode *mode)
 642 {
 643         bool interlaced = !!(mode->flags & DRM_MODE_FLAG_INTERLACE);
 644
 645         DRM_DEBUG_DRIVER("Updating global size W: %u H: %u\n",
 646                          mode->hdisplay, mode->vdisplay);
 647
 648         regmap_write(engine->regs, SUN4I_BACKEND_DISSIZE_REG,
 649                      SUN4I_BACKEND_DISSIZE(mode->hdisplay, mode->vdisplay));
 650
 651         regmap_update_bits(engine->regs, SUN4I_BACKEND_MODCTL_REG,
 652                            SUN4I_BACKEND_MODCTL_ITLMOD_EN,
 653                            interlaced ? SUN4I_BACKEND_MODCTL_ITLMOD_EN : 0);
 654
 655         DRM_DEBUG_DRIVER("Switching display backend interlaced mode %s\n",
 656                          interlaced ? "on" : "off");
 657 }
 658
 659 static int sun4i_backend_init_sat(struct device *dev) {
 660         struct sun4i_backend *backend = dev_get_drvdata(dev);
 661         int ret;
 662
 663         backend->sat_reset = devm_reset_control_get(dev, "sat");
 664         if (IS_ERR(backend->sat_reset)) {
 665                 dev_err(dev, "Couldn't get the SAT reset line\n");
 666                 return PTR_ERR(backend->sat_reset);
 667         }
 668
 669         ret = reset_control_deassert(backend->sat_reset);
 670         if (ret) {
 671                 dev_err(dev, "Couldn't deassert the SAT reset line\n");
 672                 return ret;
 673         }
 674
 675         backend->sat_clk = devm_clk_get(dev, "sat");
 676         if (IS_ERR(backend->sat_clk)) {
 677                 dev_err(dev, "Couldn't get our SAT clock\n");
 678                 ret = PTR_ERR(backend->sat_clk);
 679                 goto err_assert_reset;
 680         }
 681
 682         ret = clk_prepare_enable(backend->sat_clk);
 683         if (ret) {
 684                 dev_err(dev, "Couldn't enable the SAT clock\n");
 685                 return ret;
 686         }
 687
 688         return 0;
 689
 690 err_assert_reset:
 691         reset_control_assert(backend->sat_reset);
 692         return ret;
 693 }
 694
 695 static int sun4i_backend_free_sat(struct device *dev) {
 696         struct sun4i_backend *backend = dev_get_drvdata(dev);
 697
 698         clk_disable_unprepare(backend->sat_clk);
 699         reset_control_assert(backend->sat_reset);
 700
 701         return 0;
 702 }
 703
 704 /*
 705  * The display backend can take video output from the display frontend, or
 706  * the display enhancement unit on the A80, as input for one it its layers.
 707  * This relationship within the display pipeline is encoded in the device
 708  * tree with of_graph, and we use it here to figure out which backend, if
 709  * there are 2 or more, we are currently probing. The number would be in
 710  * the "reg" property of the upstream output port endpoint.
 711  */
 712 static int sun4i_backend_of_get_id(struct device_node *node)
 713 {
 714         struct device_node *ep, *remote;
 715         struct of_endpoint of_ep;
 716
 717         /* Input port is 0, and we want the first endpoint. */
 718         ep = of_graph_get_endpoint_by_regs(node, 0, -1);
 719         if (!ep)
 720                 return -EINVAL;
 721
 722         remote = of_graph_get_remote_endpoint(ep);
 723         of_node_put(ep);
 724         if (!remote)
 725                 return -EINVAL;
 726
 727         of_graph_parse_endpoint(remote, &of_ep);
 728         of_node_put(remote);
 729         return of_ep.id;
 730 }
 731
 732 /* TODO: This needs to take multiple pipelines into account */
 733 static struct sun4i_frontend *sun4i_backend_find_frontend(struct sun4i_drv *drv,
 734                                                           struct device_node *node)
 735 {
 736         struct device_node *port, *ep, *remote;
 737         struct sun4i_frontend *frontend;
 738
 739         port = of_graph_get_port_by_id(node, 0);
 740         if (!port)
 741                 return ERR_PTR(-EINVAL);
 742
 743         for_each_available_child_of_node(port, ep) {
 744                 remote = of_graph_get_remote_port_parent(ep);
 745                 if (!remote)
 746                         continue;
 747                 of_node_put(remote);
 748
 749                 /* does this node match any registered engines? */
 750                 list_for_each_entry(frontend, &drv->frontend_list, list) {
 751                         if (remote == frontend->node) {
 752                                 of_node_put(port);
 753                                 of_node_put(ep);
 754                                 return frontend;
 755                         }
 756                 }
 757         }
 758         of_node_put(port);
 759         return ERR_PTR(-EINVAL);
 760 }
 761
 762 static const struct sunxi_engine_ops sun4i_backend_engine_ops = {
 763         .atomic_begin                   = sun4i_backend_atomic_begin,
 764         .atomic_check                   = sun4i_backend_atomic_check,
 765         .commit                         = sun4i_backend_commit,
 766         .layers_init                    = sun4i_layers_init,
 767         .apply_color_correction         = sun4i_backend_apply_color_correction,
 768         .disable_color_correction       = sun4i_backend_disable_color_correction,
 769         .vblank_quirk                   = sun4i_backend_vblank_quirk,
 770         .mode_set                       = sun4i_backend_mode_set,
 771 };
 772
 773 static const struct regmap_config sun4i_backend_regmap_config = {
 774         .reg_bits       = 32,
 775         .val_bits       = 32,
 776         .reg_stride     = 4,
 777         .max_register   = 0x5800,
 778 };
 779
 780 static int sun4i_backend_bind(struct device *dev, struct device *master,
 781                               void *data)
 782 {
 783         struct platform_device *pdev = to_platform_device(dev);
 784         struct drm_device *drm = data;
 785         struct sun4i_drv *drv = drm->dev_private;
 786         struct sun4i_backend *backend;
 787         const struct sun4i_backend_quirks *quirks;
 788         void __iomem *regs;
 789         int i, ret;
 790
 791         backend = devm_kzalloc(dev, sizeof(*backend), GFP_KERNEL);
 792         if (!backend)
 793                 return -ENOMEM;
 794         dev_set_drvdata(dev, backend);
 795         spin_lock_init(&backend->frontend_lock);
 796
 797         if (of_property_present(dev->of_node, "interconnects")) {
 798                 /*
 799                  * This assume we have the same DMA constraints for all our the
 800                  * devices in our pipeline (all the backends, but also the
 801                  * frontends). This sounds bad, but it has always been the case
 802                  * for us, and DRM doesn't do per-device allocation either, so
 803                  * we would need to fix DRM first...
 804                  */
 805                 ret = of_dma_configure(drm->dev, dev->of_node, true);
 806                 if (ret)
 807                         return ret;
 808         }
 809
 810         backend->engine.node = dev->of_node;
 811         backend->engine.ops = &sun4i_backend_engine_ops;
 812         backend->engine.id = sun4i_backend_of_get_id(dev->of_node);
 813         if (backend->engine.id < 0)
 814                 return backend->engine.id;
 815
 816         backend->frontend = sun4i_backend_find_frontend(drv, dev->of_node);
 817         if (IS_ERR(backend->frontend))
 818                 dev_warn(dev, "Couldn't find matching frontend, frontend features disabled\n");
 819
 820         regs = devm_platform_ioremap_resource(pdev, 0);
 821         if (IS_ERR(regs))
 822                 return PTR_ERR(regs);
 823
 824         backend->reset = devm_reset_control_get(dev, NULL);
 825         if (IS_ERR(backend->reset)) {
 826                 dev_err(dev, "Couldn't get our reset line\n");
 827                 return PTR_ERR(backend->reset);
 828         }
 829
 830         ret = reset_control_deassert(backend->reset);
 831         if (ret) {
 832                 dev_err(dev, "Couldn't deassert our reset line\n");
 833                 return ret;
 834         }
 835
 836         backend->bus_clk = devm_clk_get(dev, "ahb");
 837         if (IS_ERR(backend->bus_clk)) {
 838                 dev_err(dev, "Couldn't get the backend bus clock\n");
 839                 ret = PTR_ERR(backend->bus_clk);
 840                 goto err_assert_reset;
 841         }
 842         clk_prepare_enable(backend->bus_clk);
 843
 844         backend->mod_clk = devm_clk_get(dev, "mod");
 845         if (IS_ERR(backend->mod_clk)) {
 846                 dev_err(dev, "Couldn't get the backend module clock\n");
 847                 ret = PTR_ERR(backend->mod_clk);
 848                 goto err_disable_bus_clk;
 849         }
 850
 851         ret = clk_set_rate_exclusive(backend->mod_clk, 300000000);
 852         if (ret) {
 853                 dev_err(dev, "Couldn't set the module clock frequency\n");
 854                 goto err_disable_bus_clk;
 855         }
 856
 857         clk_prepare_enable(backend->mod_clk);
 858
 859         backend->ram_clk = devm_clk_get(dev, "ram");
 860         if (IS_ERR(backend->ram_clk)) {
 861                 dev_err(dev, "Couldn't get the backend RAM clock\n");
 862                 ret = PTR_ERR(backend->ram_clk);
 863                 goto err_disable_mod_clk;
 864         }
 865         clk_prepare_enable(backend->ram_clk);
 866
 867         if (of_device_is_compatible(dev->of_node,
 868                                     "allwinner,sun8i-a33-display-backend")) {
 869                 ret = sun4i_backend_init_sat(dev);
 870                 if (ret) {
 871                         dev_err(dev, "Couldn't init SAT resources\n");
 872                         goto err_disable_ram_clk;
 873                 }
 874         }
 875
 876         backend->engine.regs = devm_regmap_init_mmio(dev, regs,
 877                                                      &sun4i_backend_regmap_config);
 878         if (IS_ERR(backend->engine.regs)) {
 879                 dev_err(dev, "Couldn't create the backend regmap\n");
 880                 return PTR_ERR(backend->engine.regs);
 881         }
 882
 883         list_add_tail(&backend->engine.list, &drv->engine_list);
 884
 885         /*
 886          * Many of the backend's layer configuration registers have
 887          * undefined default values. This poses a risk as we use
 888          * regmap_update_bits in some places, and don't overwrite
 889          * the whole register.
 890          *
 891          * Clear the registers here to have something predictable.
 892          */
 893         for (i = 0x800; i < 0x1000; i += 4)
 894                 regmap_write(backend->engine.regs, i, 0);
 895
 896         /* Disable registers autoloading */
 897         regmap_write(backend->engine.regs, SUN4I_BACKEND_REGBUFFCTL_REG,
 898                      SUN4I_BACKEND_REGBUFFCTL_AUTOLOAD_DIS);
 899
 900         /* Enable the backend */
 901         regmap_write(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
 902                      SUN4I_BACKEND_MODCTL_DEBE_EN |
 903                      SUN4I_BACKEND_MODCTL_START_CTL);
 904
 905         /* Set output selection if needed */
 906         quirks = of_device_get_match_data(dev);
 907         if (quirks->needs_output_muxing) {
 908                 /*
 909                  * We assume there is no dynamic muxing of backends
 910                  * and TCONs, so we select the backend with same ID.
 911                  *
 912                  * While dynamic selection might be interesting, since
 913                  * the CRTC is tied to the TCON, while the layers are
 914                  * tied to the backends, this means, we will need to
 915                  * switch between groups of layers. There might not be
 916                  * a way to represent this constraint in DRM.
 917                  */
 918                 regmap_update_bits(backend->engine.regs,
 919                                    SUN4I_BACKEND_MODCTL_REG,
 920                                    SUN4I_BACKEND_MODCTL_OUT_SEL,
 921                                    (backend->engine.id
 922                                     ? SUN4I_BACKEND_MODCTL_OUT_LCD1
 923                                     : SUN4I_BACKEND_MODCTL_OUT_LCD0));
 924         }
 925
 926         backend->quirks = quirks;
 927
 928         return 0;
 929
 930 err_disable_ram_clk:
 931         clk_disable_unprepare(backend->ram_clk);
 932 err_disable_mod_clk:
 933         clk_rate_exclusive_put(backend->mod_clk);
 934         clk_disable_unprepare(backend->mod_clk);
 935 err_disable_bus_clk:
 936         clk_disable_unprepare(backend->bus_clk);
 937 err_assert_reset:
 938         reset_control_assert(backend->reset);
 939         return ret;
 940 }
 941
 942 static void sun4i_backend_unbind(struct device *dev, struct device *master,
 943                                  void *data)
 944 {
 945         struct sun4i_backend *backend = dev_get_drvdata(dev);
 946
 947         list_del(&backend->engine.list);
 948
 949         if (of_device_is_compatible(dev->of_node,
 950                                     "allwinner,sun8i-a33-display-backend"))
 951                 sun4i_backend_free_sat(dev);
 952
 953         clk_disable_unprepare(backend->ram_clk);
 954         clk_rate_exclusive_put(backend->mod_clk);
 955         clk_disable_unprepare(backend->mod_clk);
 956         clk_disable_unprepare(backend->bus_clk);
 957         reset_control_assert(backend->reset);
 958 }
 959
 960 static const struct component_ops sun4i_backend_ops = {
 961         .bind   = sun4i_backend_bind,
 962         .unbind = sun4i_backend_unbind,
 963 };
 964
 965 static int sun4i_backend_probe(struct platform_device *pdev)
 966 {
 967         return component_add(&pdev->dev, &sun4i_backend_ops);
 968 }
 969
 970 static void sun4i_backend_remove(struct platform_device *pdev)
 971 {
 972         component_del(&pdev->dev, &sun4i_backend_ops);
 973 }
 974
 975 static const struct sun4i_backend_quirks sun4i_backend_quirks = {
 976         .needs_output_muxing = true,
 977 };
 978
 979 static const struct sun4i_backend_quirks sun5i_backend_quirks = {
 980 };
 981
 982 static const struct sun4i_backend_quirks sun6i_backend_quirks = {
 983 };
 984
 985 static const struct sun4i_backend_quirks sun7i_backend_quirks = {
 986         .needs_output_muxing = true,
 987 };
 988
 989 static const struct sun4i_backend_quirks sun8i_a33_backend_quirks = {
 990         .supports_lowest_plane_alpha = true,
 991 };
 992
 993 static const struct sun4i_backend_quirks sun9i_backend_quirks = {
 994 };
 995
 996 static const struct of_device_id sun4i_backend_of_table[] = {
 997         {
 998                 .compatible = "allwinner,sun4i-a10-display-backend",
 999                 .data = &sun4i_backend_quirks,
1000         },
1001         {
1002                 .compatible = "allwinner,sun5i-a13-display-backend",
1003                 .data = &sun5i_backend_quirks,
1004         },
1005         {
1006                 .compatible = "allwinner,sun6i-a31-display-backend",
1007                 .data = &sun6i_backend_quirks,
1008         },
1009         {
1010                 .compatible = "allwinner,sun7i-a20-display-backend",
1011                 .data = &sun7i_backend_quirks,
1012         },
1013         {
1014                 .compatible = "allwinner,sun8i-a23-display-backend",
1015                 .data = &sun8i_a33_backend_quirks,
1016         },
1017         {
1018                 .compatible = "allwinner,sun8i-a33-display-backend",
1019                 .data = &sun8i_a33_backend_quirks,
1020         },
1021         {
1022                 .compatible = "allwinner,sun9i-a80-display-backend",
1023                 .data = &sun9i_backend_quirks,
1024         },
1025         { }
1026 };
1027 MODULE_DEVICE_TABLE(of, sun4i_backend_of_table);
1028
1029 static struct platform_driver sun4i_backend_platform_driver = {
1030         .probe          = sun4i_backend_probe,
1031         .remove         = sun4i_backend_remove,
1032         .driver         = {
1033                 .name           = "sun4i-backend",
1034                 .of_match_table = sun4i_backend_of_table,
1035         },
1036 };
1037 module_platform_driver(sun4i_backend_platform_driver);
1038
1039 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
1040 MODULE_DESCRIPTION("Allwinner A10 Display Backend Driver");
1041 MODULE_LICENSE("GPL");