drivers/gpu/drm/sun4i/sun4i_backend.c

   1 /*
   2  * Copyright (C) 2015 Free Electrons
   3  * Copyright (C) 2015 NextThing Co
   4  *
   5  * Maxime Ripard <maxime.ripard@free-electrons.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of
  10  * the License, or (at your option) any later version.
  11  */
  12
  13 #include <drm/drmP.h>
  14 #include <drm/drm_atomic.h>
  15 #include <drm/drm_atomic_helper.h>
  16 #include <drm/drm_crtc.h>
  17 #include <drm/drm_crtc_helper.h>
  18 #include <drm/drm_fb_cma_helper.h>
  19 #include <drm/drm_gem_cma_helper.h>
  20 #include <drm/drm_plane_helper.h>
  21
  22 #include <linux/component.h>
  23 #include <linux/list.h>
  24 #include <linux/of_device.h>
  25 #include <linux/of_graph.h>
  26 #include <linux/reset.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 /*
  49  * These coefficients are taken from the A33 BSP from Allwinner.
  50  *
  51  * The first three values of each row are coded as 13-bit signed fixed-point
  52  * numbers, with 10 bits for the fractional part. The fourth value is a
  53  * constant coded as a 14-bit signed fixed-point number with 4 bits for the
  54  * fractional part.
  55  *
  56  * The values in table order give the following colorspace translation:
  57  * G = 1.164 * Y - 0.391 * U - 0.813 * V + 135
  58  * R = 1.164 * Y + 1.596 * V - 222
  59  * B = 1.164 * Y + 2.018 * U + 276
  60  *
  61  * This seems to be a conversion from Y[16:235] UV[16:240] to RGB[0:255],
  62  * following the BT601 spec.
  63  */
  64 static const u32 sunxi_bt601_yuv2rgb_coef[12] = {
  65         0x000004a7, 0x00001e6f, 0x00001cbf, 0x00000877,
  66         0x000004a7, 0x00000000, 0x00000662, 0x00003211,
  67         0x000004a7, 0x00000812, 0x00000000, 0x00002eb1,
  68 };
  69
  70 static void sun4i_backend_apply_color_correction(struct sunxi_engine *engine)
  71 {
  72         int i;
  73
  74         DRM_DEBUG_DRIVER("Applying RGB to YUV color correction\n");
  75
  76         /* Set color correction */
  77         regmap_write(engine->regs, SUN4I_BACKEND_OCCTL_REG,
  78                      SUN4I_BACKEND_OCCTL_ENABLE);
  79
  80         for (i = 0; i < 12; i++)
  81                 regmap_write(engine->regs, SUN4I_BACKEND_OCRCOEF_REG(i),
  82                              sunxi_rgb2yuv_coef[i]);
  83 }
  84
  85 static void sun4i_backend_disable_color_correction(struct sunxi_engine *engine)
  86 {
  87         DRM_DEBUG_DRIVER("Disabling color correction\n");
  88
  89         /* Disable color correction */
  90         regmap_update_bits(engine->regs, SUN4I_BACKEND_OCCTL_REG,
  91                            SUN4I_BACKEND_OCCTL_ENABLE, 0);
  92 }
  93
  94 static void sun4i_backend_commit(struct sunxi_engine *engine)
  95 {
  96         DRM_DEBUG_DRIVER("Committing changes\n");
  97
  98         regmap_write(engine->regs, SUN4I_BACKEND_REGBUFFCTL_REG,
  99                      SUN4I_BACKEND_REGBUFFCTL_AUTOLOAD_DIS |
 100                      SUN4I_BACKEND_REGBUFFCTL_LOADCTL);
 101 }
 102
 103 void sun4i_backend_layer_enable(struct sun4i_backend *backend,
 104                                 int layer, bool enable)
 105 {
 106         u32 val;
 107
 108         DRM_DEBUG_DRIVER("%sabling layer %d\n", enable ? "En" : "Dis",
 109                          layer);
 110
 111         if (enable)
 112                 val = SUN4I_BACKEND_MODCTL_LAY_EN(layer);
 113         else
 114                 val = 0;
 115
 116         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
 117                            SUN4I_BACKEND_MODCTL_LAY_EN(layer), val);
 118 }
 119
 120 static int sun4i_backend_drm_format_to_layer(u32 format, u32 *mode)
 121 {
 122         switch (format) {
 123         case DRM_FORMAT_ARGB8888:
 124                 *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB8888;
 125                 break;
 126
 127         case DRM_FORMAT_ARGB4444:
 128                 *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB4444;
 129                 break;
 130
 131         case DRM_FORMAT_ARGB1555:
 132                 *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB1555;
 133                 break;
 134
 135         case DRM_FORMAT_RGBA5551:
 136                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGBA5551;
 137                 break;
 138
 139         case DRM_FORMAT_RGBA4444:
 140                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGBA4444;
 141                 break;
 142
 143         case DRM_FORMAT_XRGB8888:
 144                 *mode = SUN4I_BACKEND_LAY_FBFMT_XRGB8888;
 145                 break;
 146
 147         case DRM_FORMAT_RGB888:
 148                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGB888;
 149                 break;
 150
 151         case DRM_FORMAT_RGB565:
 152                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGB565;
 153                 break;
 154
 155         default:
 156                 return -EINVAL;
 157         }
 158
 159         return 0;
 160 }
 161
 162 static const uint32_t sun4i_backend_formats[] = {
 163         DRM_FORMAT_ARGB1555,
 164         DRM_FORMAT_ARGB4444,
 165         DRM_FORMAT_ARGB8888,
 166         DRM_FORMAT_BGRX8888,
 167         DRM_FORMAT_RGB565,
 168         DRM_FORMAT_RGB888,
 169         DRM_FORMAT_RGBA4444,
 170         DRM_FORMAT_RGBA5551,
 171         DRM_FORMAT_UYVY,
 172         DRM_FORMAT_VYUY,
 173         DRM_FORMAT_XRGB8888,
 174         DRM_FORMAT_YUYV,
 175         DRM_FORMAT_YVYU,
 176 };
 177
 178 bool sun4i_backend_format_is_supported(uint32_t fmt, uint64_t modifier)
 179 {
 180         unsigned int i;
 181
 182         if (modifier != DRM_FORMAT_MOD_LINEAR)
 183                 return false;
 184
 185         for (i = 0; i < ARRAY_SIZE(sun4i_backend_formats); i++)
 186                 if (sun4i_backend_formats[i] == fmt)
 187                         return true;
 188
 189         return false;
 190 }
 191
 192 int sun4i_backend_update_layer_coord(struct sun4i_backend *backend,
 193                                      int layer, struct drm_plane *plane)
 194 {
 195         struct drm_plane_state *state = plane->state;
 196
 197         DRM_DEBUG_DRIVER("Updating layer %d\n", layer);
 198
 199         if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
 200                 DRM_DEBUG_DRIVER("Primary layer, updating global size W: %u H: %u\n",
 201                                  state->crtc_w, state->crtc_h);
 202                 regmap_write(backend->engine.regs, SUN4I_BACKEND_DISSIZE_REG,
 203                              SUN4I_BACKEND_DISSIZE(state->crtc_w,
 204                                                    state->crtc_h));
 205         }
 206
 207         /* Set height and width */
 208         DRM_DEBUG_DRIVER("Layer size W: %u H: %u\n",
 209                          state->crtc_w, state->crtc_h);
 210         regmap_write(backend->engine.regs, SUN4I_BACKEND_LAYSIZE_REG(layer),
 211                      SUN4I_BACKEND_LAYSIZE(state->crtc_w,
 212                                            state->crtc_h));
 213
 214         /* Set base coordinates */
 215         DRM_DEBUG_DRIVER("Layer coordinates X: %d Y: %d\n",
 216                          state->crtc_x, state->crtc_y);
 217         regmap_write(backend->engine.regs, SUN4I_BACKEND_LAYCOOR_REG(layer),
 218                      SUN4I_BACKEND_LAYCOOR(state->crtc_x,
 219                                            state->crtc_y));
 220
 221         return 0;
 222 }
 223
 224 static int sun4i_backend_update_yuv_format(struct sun4i_backend *backend,
 225                                            int layer, struct drm_plane *plane)
 226 {
 227         struct drm_plane_state *state = plane->state;
 228         struct drm_framebuffer *fb = state->fb;
 229         const struct drm_format_info *format = fb->format;
 230         const uint32_t fmt = format->format;
 231         u32 val = SUN4I_BACKEND_IYUVCTL_EN;
 232         int i;
 233
 234         for (i = 0; i < ARRAY_SIZE(sunxi_bt601_yuv2rgb_coef); i++)
 235                 regmap_write(backend->engine.regs,
 236                              SUN4I_BACKEND_YGCOEF_REG(i),
 237                              sunxi_bt601_yuv2rgb_coef[i]);
 238
 239         /*
 240          * We should do that only for a single plane, but the
 241          * framebuffer's atomic_check has our back on this.
 242          */
 243         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
 244                            SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN,
 245                            SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN);
 246
 247         /* TODO: Add support for the multi-planar YUV formats */
 248         if (format->num_planes == 1)
 249                 val |= SUN4I_BACKEND_IYUVCTL_FBFMT_PACKED_YUV422;
 250         else
 251                 DRM_DEBUG_DRIVER("Unsupported YUV format (0x%x)\n", fmt);
 252
 253         /*
 254          * Allwinner seems to list the pixel sequence from right to left, while
 255          * DRM lists it from left to right.
 256          */
 257         switch (fmt) {
 258         case DRM_FORMAT_YUYV:
 259                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_VYUY;
 260                 break;
 261         case DRM_FORMAT_YVYU:
 262                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_UYVY;
 263                 break;
 264         case DRM_FORMAT_UYVY:
 265                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_YVYU;
 266                 break;
 267         case DRM_FORMAT_VYUY:
 268                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_YUYV;
 269                 break;
 270         default:
 271                 DRM_DEBUG_DRIVER("Unsupported YUV pixel sequence (0x%x)\n",
 272                                  fmt);
 273         }
 274
 275         regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVCTL_REG, val);
 276
 277         return 0;
 278 }
 279
 280 int sun4i_backend_update_layer_formats(struct sun4i_backend *backend,
 281                                        int layer, struct drm_plane *plane)
 282 {
 283         struct drm_plane_state *state = plane->state;
 284         struct drm_framebuffer *fb = state->fb;
 285         bool interlaced = false;
 286         u32 val;
 287         int ret;
 288
 289         /* Clear the YUV mode */
 290         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
 291                            SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN, 0);
 292
 293         if (plane->state->crtc)
 294                 interlaced = plane->state->crtc->state->adjusted_mode.flags
 295                         & DRM_MODE_FLAG_INTERLACE;
 296
 297         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
 298                            SUN4I_BACKEND_MODCTL_ITLMOD_EN,
 299                            interlaced ? SUN4I_BACKEND_MODCTL_ITLMOD_EN : 0);
 300
 301         DRM_DEBUG_DRIVER("Switching display backend interlaced mode %s\n",
 302                          interlaced ? "on" : "off");
 303
 304         val = SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA(state->alpha >> 8);
 305         if (state->alpha != DRM_BLEND_ALPHA_OPAQUE)
 306                 val |= SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_EN;
 307         regmap_update_bits(backend->engine.regs,
 308                            SUN4I_BACKEND_ATTCTL_REG0(layer),
 309                            SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_MASK |
 310                            SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_EN,
 311                            val);
 312
 313         if (fb->format->is_yuv)
 314                 return sun4i_backend_update_yuv_format(backend, layer, plane);
 315
 316         ret = sun4i_backend_drm_format_to_layer(fb->format->format, &val);
 317         if (ret) {
 318                 DRM_DEBUG_DRIVER("Invalid format\n");
 319                 return ret;
 320         }
 321
 322         regmap_update_bits(backend->engine.regs,
 323                            SUN4I_BACKEND_ATTCTL_REG1(layer),
 324                            SUN4I_BACKEND_ATTCTL_REG1_LAY_FBFMT, val);
 325
 326         return 0;
 327 }
 328
 329 int sun4i_backend_update_layer_frontend(struct sun4i_backend *backend,
 330                                         int layer, uint32_t fmt)
 331 {
 332         u32 val;
 333         int ret;
 334
 335         ret = sun4i_backend_drm_format_to_layer(fmt, &val);
 336         if (ret) {
 337                 DRM_DEBUG_DRIVER("Invalid format\n");
 338                 return ret;
 339         }
 340
 341         regmap_update_bits(backend->engine.regs,
 342                            SUN4I_BACKEND_ATTCTL_REG0(layer),
 343                            SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN,
 344                            SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN);
 345
 346         regmap_update_bits(backend->engine.regs,
 347                            SUN4I_BACKEND_ATTCTL_REG1(layer),
 348                            SUN4I_BACKEND_ATTCTL_REG1_LAY_FBFMT, val);
 349
 350         return 0;
 351 }
 352
 353 static int sun4i_backend_update_yuv_buffer(struct sun4i_backend *backend,
 354                                            struct drm_framebuffer *fb,
 355                                            dma_addr_t paddr)
 356 {
 357         /* TODO: Add support for the multi-planar YUV formats */
 358         DRM_DEBUG_DRIVER("Setting packed YUV buffer address to %pad\n", &paddr);
 359         regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVADD_REG(0), paddr);
 360
 361         DRM_DEBUG_DRIVER("Layer line width: %d bits\n", fb->pitches[0] * 8);
 362         regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVLINEWIDTH_REG(0),
 363                      fb->pitches[0] * 8);
 364
 365         return 0;
 366 }
 367
 368 int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend,
 369                                       int layer, struct drm_plane *plane)
 370 {
 371         struct drm_plane_state *state = plane->state;
 372         struct drm_framebuffer *fb = state->fb;
 373         u32 lo_paddr, hi_paddr;
 374         dma_addr_t paddr;
 375
 376         /* Set the line width */
 377         DRM_DEBUG_DRIVER("Layer line width: %d bits\n", fb->pitches[0] * 8);
 378         regmap_write(backend->engine.regs,
 379                      SUN4I_BACKEND_LAYLINEWIDTH_REG(layer),
 380                      fb->pitches[0] * 8);
 381
 382         /* Get the start of the displayed memory */
 383         paddr = drm_fb_cma_get_gem_addr(fb, state, 0);
 384         DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &paddr);
 385
 386         /*
 387          * backend DMA accesses DRAM directly, bypassing the system
 388          * bus. As such, the address range is different and the buffer
 389          * address needs to be corrected.
 390          */
 391         paddr -= PHYS_OFFSET;
 392
 393         if (fb->format->is_yuv)
 394                 return sun4i_backend_update_yuv_buffer(backend, fb, paddr);
 395
 396         /* Write the 32 lower bits of the address (in bits) */
 397         lo_paddr = paddr << 3;
 398         DRM_DEBUG_DRIVER("Setting address lower bits to 0x%x\n", lo_paddr);
 399         regmap_write(backend->engine.regs,
 400                      SUN4I_BACKEND_LAYFB_L32ADD_REG(layer),
 401                      lo_paddr);
 402
 403         /* And the upper bits */
 404         hi_paddr = paddr >> 29;
 405         DRM_DEBUG_DRIVER("Setting address high bits to 0x%x\n", hi_paddr);
 406         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_LAYFB_H4ADD_REG,
 407                            SUN4I_BACKEND_LAYFB_H4ADD_MSK(layer),
 408                            SUN4I_BACKEND_LAYFB_H4ADD(layer, hi_paddr));
 409
 410         return 0;
 411 }
 412
 413 int sun4i_backend_update_layer_zpos(struct sun4i_backend *backend, int layer,
 414                                     struct drm_plane *plane)
 415 {
 416         struct drm_plane_state *state = plane->state;
 417         struct sun4i_layer_state *p_state = state_to_sun4i_layer_state(state);
 418         unsigned int priority = state->normalized_zpos;
 419         unsigned int pipe = p_state->pipe;
 420
 421         DRM_DEBUG_DRIVER("Setting layer %d's priority to %d and pipe %d\n",
 422                          layer, priority, pipe);
 423         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
 424                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL_MASK |
 425                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PRISEL_MASK,
 426                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL(p_state->pipe) |
 427                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PRISEL(priority));
 428
 429         return 0;
 430 }
 431
 432 void sun4i_backend_cleanup_layer(struct sun4i_backend *backend,
 433                                  int layer)
 434 {
 435         regmap_update_bits(backend->engine.regs,
 436                            SUN4I_BACKEND_ATTCTL_REG0(layer),
 437                            SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN |
 438                            SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN, 0);
 439 }
 440
 441 static bool sun4i_backend_plane_uses_scaler(struct drm_plane_state *state)
 442 {
 443         u16 src_h = state->src_h >> 16;
 444         u16 src_w = state->src_w >> 16;
 445
 446         DRM_DEBUG_DRIVER("Input size %dx%d, output size %dx%d\n",
 447                          src_w, src_h, state->crtc_w, state->crtc_h);
 448
 449         if ((state->crtc_h != src_h) || (state->crtc_w != src_w))
 450                 return true;
 451
 452         return false;
 453 }
 454
 455 static bool sun4i_backend_plane_uses_frontend(struct drm_plane_state *state)
 456 {
 457         struct sun4i_layer *layer = plane_to_sun4i_layer(state->plane);
 458         struct sun4i_backend *backend = layer->backend;
 459         uint32_t format = state->fb->format->format;
 460         uint64_t modifier = state->fb->modifier;
 461
 462         if (IS_ERR(backend->frontend))
 463                 return false;
 464
 465         if (!sun4i_frontend_format_is_supported(format, modifier))
 466                 return false;
 467
 468         if (!sun4i_backend_format_is_supported(format, modifier))
 469                 return true;
 470
 471         /*
 472          * TODO: The backend alone allows 2x and 4x integer scaling, including
 473          * support for an alpha component (which the frontend doesn't support).
 474          * Use the backend directly instead of the frontend in this case, with
 475          * another test to return false.
 476          */
 477
 478         if (sun4i_backend_plane_uses_scaler(state))
 479                 return true;
 480
 481         /*
 482          * Here the format is supported by both the frontend and the backend
 483          * and no frontend scaling is required, so use the backend directly.
 484          */
 485         return false;
 486 }
 487
 488 static bool sun4i_backend_plane_is_supported(struct drm_plane_state *state,
 489                                              bool *uses_frontend)
 490 {
 491         if (sun4i_backend_plane_uses_frontend(state)) {
 492                 *uses_frontend = true;
 493                 return true;
 494         }
 495
 496         *uses_frontend = false;
 497
 498         /* Scaling is not supported without the frontend. */
 499         if (sun4i_backend_plane_uses_scaler(state))
 500                 return false;
 501
 502         return true;
 503 }
 504
 505 static void sun4i_backend_atomic_begin(struct sunxi_engine *engine,
 506                                        struct drm_crtc_state *old_state)
 507 {
 508         u32 val;
 509
 510         WARN_ON(regmap_read_poll_timeout(engine->regs,
 511                                          SUN4I_BACKEND_REGBUFFCTL_REG,
 512                                          val, !(val & SUN4I_BACKEND_REGBUFFCTL_LOADCTL),
 513                                          100, 50000));
 514 }
 515
 516 static int sun4i_backend_atomic_check(struct sunxi_engine *engine,
 517                                       struct drm_crtc_state *crtc_state)
 518 {
 519         struct drm_plane_state *plane_states[SUN4I_BACKEND_NUM_LAYERS] = { 0 };
 520         struct sun4i_backend *backend = engine_to_sun4i_backend(engine);
 521         struct drm_atomic_state *state = crtc_state->state;
 522         struct drm_device *drm = state->dev;
 523         struct drm_plane *plane;
 524         unsigned int num_planes = 0;
 525         unsigned int num_alpha_planes = 0;
 526         unsigned int num_frontend_planes = 0;
 527         unsigned int num_alpha_planes_max = 1;
 528         unsigned int num_yuv_planes = 0;
 529         unsigned int current_pipe = 0;
 530         unsigned int i;
 531
 532         DRM_DEBUG_DRIVER("Starting checking our planes\n");
 533
 534         if (!crtc_state->planes_changed)
 535                 return 0;
 536
 537         drm_for_each_plane_mask(plane, drm, crtc_state->plane_mask) {
 538                 struct drm_plane_state *plane_state =
 539                         drm_atomic_get_plane_state(state, plane);
 540                 struct sun4i_layer_state *layer_state =
 541                         state_to_sun4i_layer_state(plane_state);
 542                 struct drm_framebuffer *fb = plane_state->fb;
 543                 struct drm_format_name_buf format_name;
 544
 545                 if (!sun4i_backend_plane_is_supported(plane_state,
 546                                                       &layer_state->uses_frontend))
 547                         return -EINVAL;
 548
 549                 if (layer_state->uses_frontend) {
 550                         DRM_DEBUG_DRIVER("Using the frontend for plane %d\n",
 551                                          plane->index);
 552                         num_frontend_planes++;
 553                 } else {
 554                         if (fb->format->is_yuv) {
 555                                 DRM_DEBUG_DRIVER("Plane FB format is YUV\n");
 556                                 num_yuv_planes++;
 557                         }
 558                 }
 559
 560                 DRM_DEBUG_DRIVER("Plane FB format is %s\n",
 561                                  drm_get_format_name(fb->format->format,
 562                                                      &format_name));
 563                 if (fb->format->has_alpha || (plane_state->alpha != DRM_BLEND_ALPHA_OPAQUE))
 564                         num_alpha_planes++;
 565
 566                 DRM_DEBUG_DRIVER("Plane zpos is %d\n",
 567                                  plane_state->normalized_zpos);
 568
 569                 /* Sort our planes by Zpos */
 570                 plane_states[plane_state->normalized_zpos] = plane_state;
 571
 572                 num_planes++;
 573         }
 574
 575         /* All our planes were disabled, bail out */
 576         if (!num_planes)
 577                 return 0;
 578
 579         /*
 580          * The hardware is a bit unusual here.
 581          *
 582          * Even though it supports 4 layers, it does the composition
 583          * in two separate steps.
 584          *
 585          * The first one is assigning a layer to one of its two
 586          * pipes. If more that 1 layer is assigned to the same pipe,
 587          * and if pixels overlaps, the pipe will take the pixel from
 588          * the layer with the highest priority.
 589          *
 590          * The second step is the actual alpha blending, that takes
 591          * the two pipes as input, and uses the potential alpha
 592          * component to do the transparency between the two.
 593          *
 594          * This two-step scenario makes us unable to guarantee a
 595          * robust alpha blending between the 4 layers in all
 596          * situations, since this means that we need to have one layer
 597          * with alpha at the lowest position of our two pipes.
 598          *
 599          * However, we cannot even do that on every platform, since
 600          * the hardware has a bug where the lowest plane of the lowest
 601          * pipe (pipe 0, priority 0), if it has any alpha, will
 602          * discard the pixel data entirely and just display the pixels
 603          * in the background color (black by default).
 604          *
 605          * This means that on the affected platforms, we effectively
 606          * have only three valid configurations with alpha, all of
 607          * them with the alpha being on pipe1 with the lowest
 608          * position, which can be 1, 2 or 3 depending on the number of
 609          * planes and their zpos.
 610          */
 611
 612         /* For platforms that are not affected by the issue described above. */
 613         if (backend->quirks->supports_lowest_plane_alpha)
 614                 num_alpha_planes_max++;
 615
 616         if (num_alpha_planes > num_alpha_planes_max) {
 617                 DRM_DEBUG_DRIVER("Too many planes with alpha, rejecting...\n");
 618                 return -EINVAL;
 619         }
 620
 621         /* We can't have an alpha plane at the lowest position */
 622         if (!backend->quirks->supports_lowest_plane_alpha &&
 623             (plane_states[0]->fb->format->has_alpha ||
 624             (plane_states[0]->alpha != DRM_BLEND_ALPHA_OPAQUE)))
 625                 return -EINVAL;
 626
 627         for (i = 1; i < num_planes; i++) {
 628                 struct drm_plane_state *p_state = plane_states[i];
 629                 struct drm_framebuffer *fb = p_state->fb;
 630                 struct sun4i_layer_state *s_state = state_to_sun4i_layer_state(p_state);
 631
 632                 /*
 633                  * The only alpha position is the lowest plane of the
 634                  * second pipe.
 635                  */
 636                 if (fb->format->has_alpha || (p_state->alpha != DRM_BLEND_ALPHA_OPAQUE))
 637                         current_pipe++;
 638
 639                 s_state->pipe = current_pipe;
 640         }
 641
 642         /* We can only have a single YUV plane at a time */
 643         if (num_yuv_planes > SUN4I_BACKEND_NUM_YUV_PLANES) {
 644                 DRM_DEBUG_DRIVER("Too many planes with YUV, rejecting...\n");
 645                 return -EINVAL;
 646         }
 647
 648         if (num_frontend_planes > SUN4I_BACKEND_NUM_FRONTEND_LAYERS) {
 649                 DRM_DEBUG_DRIVER("Too many planes going through the frontend, rejecting\n");
 650                 return -EINVAL;
 651         }
 652
 653         DRM_DEBUG_DRIVER("State valid with %u planes, %u alpha, %u video, %u YUV\n",
 654                          num_planes, num_alpha_planes, num_frontend_planes,
 655                          num_yuv_planes);
 656
 657         return 0;
 658 }
 659
 660 static void sun4i_backend_vblank_quirk(struct sunxi_engine *engine)
 661 {
 662         struct sun4i_backend *backend = engine_to_sun4i_backend(engine);
 663         struct sun4i_frontend *frontend = backend->frontend;
 664
 665         if (!frontend)
 666                 return;
 667
 668         /*
 669          * In a teardown scenario with the frontend involved, we have
 670          * to keep the frontend enabled until the next vblank, and
 671          * only then disable it.
 672          *
 673          * This is due to the fact that the backend will not take into
 674          * account the new configuration (with the plane that used to
 675          * be fed by the frontend now disabled) until we write to the
 676          * commit bit and the hardware fetches the new configuration
 677          * during the next vblank.
 678          *
 679          * So we keep the frontend around in order to prevent any
 680          * visual artifacts.
 681          */
 682         spin_lock(&backend->frontend_lock);
 683         if (backend->frontend_teardown) {
 684                 sun4i_frontend_exit(frontend);
 685                 backend->frontend_teardown = false;
 686         }
 687         spin_unlock(&backend->frontend_lock);
 688 };
 689
 690 static int sun4i_backend_init_sat(struct device *dev) {
 691         struct sun4i_backend *backend = dev_get_drvdata(dev);
 692         int ret;
 693
 694         backend->sat_reset = devm_reset_control_get(dev, "sat");
 695         if (IS_ERR(backend->sat_reset)) {
 696                 dev_err(dev, "Couldn't get the SAT reset line\n");
 697                 return PTR_ERR(backend->sat_reset);
 698         }
 699
 700         ret = reset_control_deassert(backend->sat_reset);
 701         if (ret) {
 702                 dev_err(dev, "Couldn't deassert the SAT reset line\n");
 703                 return ret;
 704         }
 705
 706         backend->sat_clk = devm_clk_get(dev, "sat");
 707         if (IS_ERR(backend->sat_clk)) {
 708                 dev_err(dev, "Couldn't get our SAT clock\n");
 709                 ret = PTR_ERR(backend->sat_clk);
 710                 goto err_assert_reset;
 711         }
 712
 713         ret = clk_prepare_enable(backend->sat_clk);
 714         if (ret) {
 715                 dev_err(dev, "Couldn't enable the SAT clock\n");
 716                 return ret;
 717         }
 718
 719         return 0;
 720
 721 err_assert_reset:
 722         reset_control_assert(backend->sat_reset);
 723         return ret;
 724 }
 725
 726 static int sun4i_backend_free_sat(struct device *dev) {
 727         struct sun4i_backend *backend = dev_get_drvdata(dev);
 728
 729         clk_disable_unprepare(backend->sat_clk);
 730         reset_control_assert(backend->sat_reset);
 731
 732         return 0;
 733 }
 734
 735 /*
 736  * The display backend can take video output from the display frontend, or
 737  * the display enhancement unit on the A80, as input for one it its layers.
 738  * This relationship within the display pipeline is encoded in the device
 739  * tree with of_graph, and we use it here to figure out which backend, if
 740  * there are 2 or more, we are currently probing. The number would be in
 741  * the "reg" property of the upstream output port endpoint.
 742  */
 743 static int sun4i_backend_of_get_id(struct device_node *node)
 744 {
 745         struct device_node *port, *ep;
 746         int ret = -EINVAL;
 747
 748         /* input is port 0 */
 749         port = of_graph_get_port_by_id(node, 0);
 750         if (!port)
 751                 return -EINVAL;
 752
 753         /* try finding an upstream endpoint */
 754         for_each_available_child_of_node(port, ep) {
 755                 struct device_node *remote;
 756                 u32 reg;
 757
 758                 remote = of_graph_get_remote_endpoint(ep);
 759                 if (!remote)
 760                         continue;
 761
 762                 ret = of_property_read_u32(remote, "reg", &reg);
 763                 if (ret)
 764                         continue;
 765
 766                 ret = reg;
 767         }
 768
 769         of_node_put(port);
 770
 771         return ret;
 772 }
 773
 774 /* TODO: This needs to take multiple pipelines into account */
 775 static struct sun4i_frontend *sun4i_backend_find_frontend(struct sun4i_drv *drv,
 776                                                           struct device_node *node)
 777 {
 778         struct device_node *port, *ep, *remote;
 779         struct sun4i_frontend *frontend;
 780
 781         port = of_graph_get_port_by_id(node, 0);
 782         if (!port)
 783                 return ERR_PTR(-EINVAL);
 784
 785         for_each_available_child_of_node(port, ep) {
 786                 remote = of_graph_get_remote_port_parent(ep);
 787                 if (!remote)
 788                         continue;
 789
 790                 /* does this node match any registered engines? */
 791                 list_for_each_entry(frontend, &drv->frontend_list, list) {
 792                         if (remote == frontend->node) {
 793                                 of_node_put(remote);
 794                                 of_node_put(port);
 795                                 return frontend;
 796                         }
 797                 }
 798         }
 799
 800         return ERR_PTR(-EINVAL);
 801 }
 802
 803 static const struct sunxi_engine_ops sun4i_backend_engine_ops = {
 804         .atomic_begin                   = sun4i_backend_atomic_begin,
 805         .atomic_check                   = sun4i_backend_atomic_check,
 806         .commit                         = sun4i_backend_commit,
 807         .layers_init                    = sun4i_layers_init,
 808         .apply_color_correction         = sun4i_backend_apply_color_correction,
 809         .disable_color_correction       = sun4i_backend_disable_color_correction,
 810         .vblank_quirk                   = sun4i_backend_vblank_quirk,
 811 };
 812
 813 static struct regmap_config sun4i_backend_regmap_config = {
 814         .reg_bits       = 32,
 815         .val_bits       = 32,
 816         .reg_stride     = 4,
 817         .max_register   = 0x5800,
 818 };
 819
 820 static int sun4i_backend_bind(struct device *dev, struct device *master,
 821                               void *data)
 822 {
 823         struct platform_device *pdev = to_platform_device(dev);
 824         struct drm_device *drm = data;
 825         struct sun4i_drv *drv = drm->dev_private;
 826         struct sun4i_backend *backend;
 827         const struct sun4i_backend_quirks *quirks;
 828         struct resource *res;
 829         void __iomem *regs;
 830         int i, ret;
 831
 832         backend = devm_kzalloc(dev, sizeof(*backend), GFP_KERNEL);
 833         if (!backend)
 834                 return -ENOMEM;
 835         dev_set_drvdata(dev, backend);
 836         spin_lock_init(&backend->frontend_lock);
 837
 838         backend->engine.node = dev->of_node;
 839         backend->engine.ops = &sun4i_backend_engine_ops;
 840         backend->engine.id = sun4i_backend_of_get_id(dev->of_node);
 841         if (backend->engine.id < 0)
 842                 return backend->engine.id;
 843
 844         backend->frontend = sun4i_backend_find_frontend(drv, dev->of_node);
 845         if (IS_ERR(backend->frontend))
 846                 dev_warn(dev, "Couldn't find matching frontend, frontend features disabled\n");
 847
 848         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 849         regs = devm_ioremap_resource(dev, res);
 850         if (IS_ERR(regs))
 851                 return PTR_ERR(regs);
 852
 853         backend->reset = devm_reset_control_get(dev, NULL);
 854         if (IS_ERR(backend->reset)) {
 855                 dev_err(dev, "Couldn't get our reset line\n");
 856                 return PTR_ERR(backend->reset);
 857         }
 858
 859         ret = reset_control_deassert(backend->reset);
 860         if (ret) {
 861                 dev_err(dev, "Couldn't deassert our reset line\n");
 862                 return ret;
 863         }
 864
 865         backend->bus_clk = devm_clk_get(dev, "ahb");
 866         if (IS_ERR(backend->bus_clk)) {
 867                 dev_err(dev, "Couldn't get the backend bus clock\n");
 868                 ret = PTR_ERR(backend->bus_clk);
 869                 goto err_assert_reset;
 870         }
 871         clk_prepare_enable(backend->bus_clk);
 872
 873         backend->mod_clk = devm_clk_get(dev, "mod");
 874         if (IS_ERR(backend->mod_clk)) {
 875                 dev_err(dev, "Couldn't get the backend module clock\n");
 876                 ret = PTR_ERR(backend->mod_clk);
 877                 goto err_disable_bus_clk;
 878         }
 879         clk_prepare_enable(backend->mod_clk);
 880
 881         backend->ram_clk = devm_clk_get(dev, "ram");
 882         if (IS_ERR(backend->ram_clk)) {
 883                 dev_err(dev, "Couldn't get the backend RAM clock\n");
 884                 ret = PTR_ERR(backend->ram_clk);
 885                 goto err_disable_mod_clk;
 886         }
 887         clk_prepare_enable(backend->ram_clk);
 888
 889         if (of_device_is_compatible(dev->of_node,
 890                                     "allwinner,sun8i-a33-display-backend")) {
 891                 ret = sun4i_backend_init_sat(dev);
 892                 if (ret) {
 893                         dev_err(dev, "Couldn't init SAT resources\n");
 894                         goto err_disable_ram_clk;
 895                 }
 896         }
 897
 898         backend->engine.regs = devm_regmap_init_mmio(dev, regs,
 899                                                      &sun4i_backend_regmap_config);
 900         if (IS_ERR(backend->engine.regs)) {
 901                 dev_err(dev, "Couldn't create the backend regmap\n");
 902                 return PTR_ERR(backend->engine.regs);
 903         }
 904
 905         list_add_tail(&backend->engine.list, &drv->engine_list);
 906
 907         /*
 908          * Many of the backend's layer configuration registers have
 909          * undefined default values. This poses a risk as we use
 910          * regmap_update_bits in some places, and don't overwrite
 911          * the whole register.
 912          *
 913          * Clear the registers here to have something predictable.
 914          */
 915         for (i = 0x800; i < 0x1000; i += 4)
 916                 regmap_write(backend->engine.regs, i, 0);
 917
 918         /* Disable registers autoloading */
 919         regmap_write(backend->engine.regs, SUN4I_BACKEND_REGBUFFCTL_REG,
 920                      SUN4I_BACKEND_REGBUFFCTL_AUTOLOAD_DIS);
 921
 922         /* Enable the backend */
 923         regmap_write(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
 924                      SUN4I_BACKEND_MODCTL_DEBE_EN |
 925                      SUN4I_BACKEND_MODCTL_START_CTL);
 926
 927         /* Set output selection if needed */
 928         quirks = of_device_get_match_data(dev);
 929         if (quirks->needs_output_muxing) {
 930                 /*
 931                  * We assume there is no dynamic muxing of backends
 932                  * and TCONs, so we select the backend with same ID.
 933                  *
 934                  * While dynamic selection might be interesting, since
 935                  * the CRTC is tied to the TCON, while the layers are
 936                  * tied to the backends, this means, we will need to
 937                  * switch between groups of layers. There might not be
 938                  * a way to represent this constraint in DRM.
 939                  */
 940                 regmap_update_bits(backend->engine.regs,
 941                                    SUN4I_BACKEND_MODCTL_REG,
 942                                    SUN4I_BACKEND_MODCTL_OUT_SEL,
 943                                    (backend->engine.id
 944                                     ? SUN4I_BACKEND_MODCTL_OUT_LCD1
 945                                     : SUN4I_BACKEND_MODCTL_OUT_LCD0));
 946         }
 947
 948         backend->quirks = quirks;
 949
 950         return 0;
 951
 952 err_disable_ram_clk:
 953         clk_disable_unprepare(backend->ram_clk);
 954 err_disable_mod_clk:
 955         clk_disable_unprepare(backend->mod_clk);
 956 err_disable_bus_clk:
 957         clk_disable_unprepare(backend->bus_clk);
 958 err_assert_reset:
 959         reset_control_assert(backend->reset);
 960         return ret;
 961 }
 962
 963 static void sun4i_backend_unbind(struct device *dev, struct device *master,
 964                                  void *data)
 965 {
 966         struct sun4i_backend *backend = dev_get_drvdata(dev);
 967
 968         list_del(&backend->engine.list);
 969
 970         if (of_device_is_compatible(dev->of_node,
 971                                     "allwinner,sun8i-a33-display-backend"))
 972                 sun4i_backend_free_sat(dev);
 973
 974         clk_disable_unprepare(backend->ram_clk);
 975         clk_disable_unprepare(backend->mod_clk);
 976         clk_disable_unprepare(backend->bus_clk);
 977         reset_control_assert(backend->reset);
 978 }
 979
 980 static const struct component_ops sun4i_backend_ops = {
 981         .bind   = sun4i_backend_bind,
 982         .unbind = sun4i_backend_unbind,
 983 };
 984
 985 static int sun4i_backend_probe(struct platform_device *pdev)
 986 {
 987         return component_add(&pdev->dev, &sun4i_backend_ops);
 988 }
 989
 990 static int sun4i_backend_remove(struct platform_device *pdev)
 991 {
 992         component_del(&pdev->dev, &sun4i_backend_ops);
 993
 994         return 0;
 995 }
 996
 997 static const struct sun4i_backend_quirks sun4i_backend_quirks = {
 998         .needs_output_muxing = true,
 999 };
1000
1001 static const struct sun4i_backend_quirks sun5i_backend_quirks = {
1002 };
1003
1004 static const struct sun4i_backend_quirks sun6i_backend_quirks = {
1005 };
1006
1007 static const struct sun4i_backend_quirks sun7i_backend_quirks = {
1008         .needs_output_muxing = true,
1009         .supports_lowest_plane_alpha = true,
1010 };
1011
1012 static const struct sun4i_backend_quirks sun8i_a33_backend_quirks = {
1013         .supports_lowest_plane_alpha = true,
1014 };
1015
1016 static const struct sun4i_backend_quirks sun9i_backend_quirks = {
1017 };
1018
1019 static const struct of_device_id sun4i_backend_of_table[] = {
1020         {
1021                 .compatible = "allwinner,sun4i-a10-display-backend",
1022                 .data = &sun4i_backend_quirks,
1023         },
1024         {
1025                 .compatible = "allwinner,sun5i-a13-display-backend",
1026                 .data = &sun5i_backend_quirks,
1027         },
1028         {
1029                 .compatible = "allwinner,sun6i-a31-display-backend",
1030                 .data = &sun6i_backend_quirks,
1031         },
1032         {
1033                 .compatible = "allwinner,sun7i-a20-display-backend",
1034                 .data = &sun7i_backend_quirks,
1035         },
1036         {
1037                 .compatible = "allwinner,sun8i-a33-display-backend",
1038                 .data = &sun8i_a33_backend_quirks,
1039         },
1040         {
1041                 .compatible = "allwinner,sun9i-a80-display-backend",
1042                 .data = &sun9i_backend_quirks,
1043         },
1044         { }
1045 };
1046 MODULE_DEVICE_TABLE(of, sun4i_backend_of_table);
1047
1048 static struct platform_driver sun4i_backend_platform_driver = {
1049         .probe          = sun4i_backend_probe,
1050         .remove         = sun4i_backend_remove,
1051         .driver         = {
1052                 .name           = "sun4i-backend",
1053                 .of_match_table = sun4i_backend_of_table,
1054         },
1055 };
1056 module_platform_driver(sun4i_backend_platform_driver);
1057
1058 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
1059 MODULE_DESCRIPTION("Allwinner A10 Display Backend Driver");
1060 MODULE_LICENSE("GPL");