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
  39 static const u32 sunxi_rgb2yuv_coef[12] = {
  40         0x00000107, 0x00000204, 0x00000064, 0x00000108,
  41         0x00003f69, 0x00003ed6, 0x000001c1, 0x00000808,
  42         0x000001c1, 0x00003e88, 0x00003fb8, 0x00000808
  43 };
  44
  45 /*
  46  * These coefficients are taken from the A33 BSP from Allwinner.
  47  *
  48  * The formula is for each component, each coefficient being multiplied by
  49  * 1024 and each constant being multiplied by 16:
  50  * G = 1.164 * Y - 0.391 * U - 0.813 * V + 135
  51  * R = 1.164 * Y + 1.596 * V - 222
  52  * B = 1.164 * Y + 2.018 * U + 276
  53  *
  54  * This seems to be a conversion from Y[16:235] UV[16:240] to RGB[0:255],
  55  * following the BT601 spec.
  56  */
  57 static const u32 sunxi_bt601_yuv2rgb_coef[12] = {
  58         0x000004a7, 0x00001e6f, 0x00001cbf, 0x00000877,
  59         0x000004a7, 0x00000000, 0x00000662, 0x00003211,
  60         0x000004a7, 0x00000812, 0x00000000, 0x00002eb1,
  61 };
  62
  63 static inline bool sun4i_backend_format_is_planar_yuv(uint32_t format)
  64 {
  65         switch (format) {
  66         case DRM_FORMAT_YUV411:
  67         case DRM_FORMAT_YUV422:
  68         case DRM_FORMAT_YUV444:
  69                 return true;
  70         default:
  71                 return false;
  72         }
  73 }
  74
  75 static inline bool sun4i_backend_format_is_packed_yuv422(uint32_t format)
  76 {
  77         switch (format) {
  78         case DRM_FORMAT_YUYV:
  79         case DRM_FORMAT_YVYU:
  80         case DRM_FORMAT_UYVY:
  81         case DRM_FORMAT_VYUY:
  82                 return true;
  83
  84         default:
  85                 return false;
  86         }
  87 }
  88
  89 static void sun4i_backend_apply_color_correction(struct sunxi_engine *engine)
  90 {
  91         int i;
  92
  93         DRM_DEBUG_DRIVER("Applying RGB to YUV color correction\n");
  94
  95         /* Set color correction */
  96         regmap_write(engine->regs, SUN4I_BACKEND_OCCTL_REG,
  97                      SUN4I_BACKEND_OCCTL_ENABLE);
  98
  99         for (i = 0; i < 12; i++)
 100                 regmap_write(engine->regs, SUN4I_BACKEND_OCRCOEF_REG(i),
 101                              sunxi_rgb2yuv_coef[i]);
 102 }
 103
 104 static void sun4i_backend_disable_color_correction(struct sunxi_engine *engine)
 105 {
 106         DRM_DEBUG_DRIVER("Disabling color correction\n");
 107
 108         /* Disable color correction */
 109         regmap_update_bits(engine->regs, SUN4I_BACKEND_OCCTL_REG,
 110                            SUN4I_BACKEND_OCCTL_ENABLE, 0);
 111 }
 112
 113 static void sun4i_backend_commit(struct sunxi_engine *engine)
 114 {
 115         DRM_DEBUG_DRIVER("Committing changes\n");
 116
 117         regmap_write(engine->regs, SUN4I_BACKEND_REGBUFFCTL_REG,
 118                      SUN4I_BACKEND_REGBUFFCTL_AUTOLOAD_DIS |
 119                      SUN4I_BACKEND_REGBUFFCTL_LOADCTL);
 120 }
 121
 122 void sun4i_backend_layer_enable(struct sun4i_backend *backend,
 123                                 int layer, bool enable)
 124 {
 125         u32 val;
 126
 127         DRM_DEBUG_DRIVER("%sabling layer %d\n", enable ? "En" : "Dis",
 128                          layer);
 129
 130         if (enable)
 131                 val = SUN4I_BACKEND_MODCTL_LAY_EN(layer);
 132         else
 133                 val = 0;
 134
 135         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
 136                            SUN4I_BACKEND_MODCTL_LAY_EN(layer), val);
 137 }
 138
 139 static int sun4i_backend_drm_format_to_layer(u32 format, u32 *mode)
 140 {
 141         switch (format) {
 142         case DRM_FORMAT_ARGB8888:
 143                 *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB8888;
 144                 break;
 145
 146         case DRM_FORMAT_ARGB4444:
 147                 *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB4444;
 148                 break;
 149
 150         case DRM_FORMAT_ARGB1555:
 151                 *mode = SUN4I_BACKEND_LAY_FBFMT_ARGB1555;
 152                 break;
 153
 154         case DRM_FORMAT_RGBA5551:
 155                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGBA5551;
 156                 break;
 157
 158         case DRM_FORMAT_RGBA4444:
 159                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGBA4444;
 160                 break;
 161
 162         case DRM_FORMAT_XRGB8888:
 163                 *mode = SUN4I_BACKEND_LAY_FBFMT_XRGB8888;
 164                 break;
 165
 166         case DRM_FORMAT_RGB888:
 167                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGB888;
 168                 break;
 169
 170         case DRM_FORMAT_RGB565:
 171                 *mode = SUN4I_BACKEND_LAY_FBFMT_RGB565;
 172                 break;
 173
 174         default:
 175                 return -EINVAL;
 176         }
 177
 178         return 0;
 179 }
 180
 181 int sun4i_backend_update_layer_coord(struct sun4i_backend *backend,
 182                                      int layer, struct drm_plane *plane)
 183 {
 184         struct drm_plane_state *state = plane->state;
 185
 186         DRM_DEBUG_DRIVER("Updating layer %d\n", layer);
 187
 188         if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
 189                 DRM_DEBUG_DRIVER("Primary layer, updating global size W: %u H: %u\n",
 190                                  state->crtc_w, state->crtc_h);
 191                 regmap_write(backend->engine.regs, SUN4I_BACKEND_DISSIZE_REG,
 192                              SUN4I_BACKEND_DISSIZE(state->crtc_w,
 193                                                    state->crtc_h));
 194         }
 195
 196         /* Set height and width */
 197         DRM_DEBUG_DRIVER("Layer size W: %u H: %u\n",
 198                          state->crtc_w, state->crtc_h);
 199         regmap_write(backend->engine.regs, SUN4I_BACKEND_LAYSIZE_REG(layer),
 200                      SUN4I_BACKEND_LAYSIZE(state->crtc_w,
 201                                            state->crtc_h));
 202
 203         /* Set base coordinates */
 204         DRM_DEBUG_DRIVER("Layer coordinates X: %d Y: %d\n",
 205                          state->crtc_x, state->crtc_y);
 206         regmap_write(backend->engine.regs, SUN4I_BACKEND_LAYCOOR_REG(layer),
 207                      SUN4I_BACKEND_LAYCOOR(state->crtc_x,
 208                                            state->crtc_y));
 209
 210         return 0;
 211 }
 212
 213 static int sun4i_backend_update_yuv_format(struct sun4i_backend *backend,
 214                                            int layer, struct drm_plane *plane)
 215 {
 216         struct drm_plane_state *state = plane->state;
 217         struct drm_framebuffer *fb = state->fb;
 218         uint32_t format = fb->format->format;
 219         u32 val = SUN4I_BACKEND_IYUVCTL_EN;
 220         int i;
 221
 222         for (i = 0; i < ARRAY_SIZE(sunxi_bt601_yuv2rgb_coef); i++)
 223                 regmap_write(backend->engine.regs,
 224                              SUN4I_BACKEND_YGCOEF_REG(i),
 225                              sunxi_bt601_yuv2rgb_coef[i]);
 226
 227         /*
 228          * We should do that only for a single plane, but the
 229          * framebuffer's atomic_check has our back on this.
 230          */
 231         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
 232                            SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN,
 233                            SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN);
 234
 235         /* TODO: Add support for the multi-planar YUV formats */
 236         if (sun4i_backend_format_is_packed_yuv422(format))
 237                 val |= SUN4I_BACKEND_IYUVCTL_FBFMT_PACKED_YUV422;
 238         else
 239                 DRM_DEBUG_DRIVER("Unsupported YUV format (0x%x)\n", format);
 240
 241         /*
 242          * Allwinner seems to list the pixel sequence from right to left, while
 243          * DRM lists it from left to right.
 244          */
 245         switch (format) {
 246         case DRM_FORMAT_YUYV:
 247                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_VYUY;
 248                 break;
 249         case DRM_FORMAT_YVYU:
 250                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_UYVY;
 251                 break;
 252         case DRM_FORMAT_UYVY:
 253                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_YVYU;
 254                 break;
 255         case DRM_FORMAT_VYUY:
 256                 val |= SUN4I_BACKEND_IYUVCTL_FBPS_YUYV;
 257                 break;
 258         default:
 259                 DRM_DEBUG_DRIVER("Unsupported YUV pixel sequence (0x%x)\n",
 260                                  format);
 261         }
 262
 263         regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVCTL_REG, val);
 264
 265         return 0;
 266 }
 267
 268 int sun4i_backend_update_layer_formats(struct sun4i_backend *backend,
 269                                        int layer, struct drm_plane *plane)
 270 {
 271         struct drm_plane_state *state = plane->state;
 272         struct drm_framebuffer *fb = state->fb;
 273         bool interlaced = false;
 274         u32 val;
 275         int ret;
 276
 277         /* Clear the YUV mode */
 278         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
 279                            SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN, 0);
 280
 281         if (plane->state->crtc)
 282                 interlaced = plane->state->crtc->state->adjusted_mode.flags
 283                         & DRM_MODE_FLAG_INTERLACE;
 284
 285         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
 286                            SUN4I_BACKEND_MODCTL_ITLMOD_EN,
 287                            interlaced ? SUN4I_BACKEND_MODCTL_ITLMOD_EN : 0);
 288
 289         DRM_DEBUG_DRIVER("Switching display backend interlaced mode %s\n",
 290                          interlaced ? "on" : "off");
 291
 292         val = SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA(state->alpha >> 8);
 293         if (state->alpha != DRM_BLEND_ALPHA_OPAQUE)
 294                 val |= SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_EN;
 295         regmap_update_bits(backend->engine.regs,
 296                            SUN4I_BACKEND_ATTCTL_REG0(layer),
 297                            SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_MASK |
 298                            SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_EN,
 299                            val);
 300
 301         if (fb->format->is_yuv)
 302                 return sun4i_backend_update_yuv_format(backend, layer, plane);
 303
 304         ret = sun4i_backend_drm_format_to_layer(fb->format->format, &val);
 305         if (ret) {
 306                 DRM_DEBUG_DRIVER("Invalid format\n");
 307                 return ret;
 308         }
 309
 310         regmap_update_bits(backend->engine.regs,
 311                            SUN4I_BACKEND_ATTCTL_REG1(layer),
 312                            SUN4I_BACKEND_ATTCTL_REG1_LAY_FBFMT, val);
 313
 314         return 0;
 315 }
 316
 317 int sun4i_backend_update_layer_frontend(struct sun4i_backend *backend,
 318                                         int layer, uint32_t fmt)
 319 {
 320         u32 val;
 321         int ret;
 322
 323         ret = sun4i_backend_drm_format_to_layer(fmt, &val);
 324         if (ret) {
 325                 DRM_DEBUG_DRIVER("Invalid format\n");
 326                 return ret;
 327         }
 328
 329         regmap_update_bits(backend->engine.regs,
 330                            SUN4I_BACKEND_ATTCTL_REG0(layer),
 331                            SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN,
 332                            SUN4I_BACKEND_ATTCTL_REG0_LAY_VDOEN);
 333
 334         regmap_update_bits(backend->engine.regs,
 335                            SUN4I_BACKEND_ATTCTL_REG1(layer),
 336                            SUN4I_BACKEND_ATTCTL_REG1_LAY_FBFMT, val);
 337
 338         return 0;
 339 }
 340
 341 static int sun4i_backend_update_yuv_buffer(struct sun4i_backend *backend,
 342                                            struct drm_framebuffer *fb,
 343                                            dma_addr_t paddr)
 344 {
 345         /* TODO: Add support for the multi-planar YUV formats */
 346         DRM_DEBUG_DRIVER("Setting packed YUV buffer address to %pad\n", &paddr);
 347         regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVADD_REG(0), paddr);
 348
 349         DRM_DEBUG_DRIVER("Layer line width: %d bits\n", fb->pitches[0] * 8);
 350         regmap_write(backend->engine.regs, SUN4I_BACKEND_IYUVLINEWIDTH_REG(0),
 351                      fb->pitches[0] * 8);
 352
 353         return 0;
 354 }
 355
 356 int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend,
 357                                       int layer, struct drm_plane *plane)
 358 {
 359         struct drm_plane_state *state = plane->state;
 360         struct drm_framebuffer *fb = state->fb;
 361         u32 lo_paddr, hi_paddr;
 362         dma_addr_t paddr;
 363
 364         /* Set the line width */
 365         DRM_DEBUG_DRIVER("Layer line width: %d bits\n", fb->pitches[0] * 8);
 366         regmap_write(backend->engine.regs,
 367                      SUN4I_BACKEND_LAYLINEWIDTH_REG(layer),
 368                      fb->pitches[0] * 8);
 369
 370         /* Get the start of the displayed memory */
 371         paddr = drm_fb_cma_get_gem_addr(fb, state, 0);
 372         DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &paddr);
 373
 374         /*
 375          * backend DMA accesses DRAM directly, bypassing the system
 376          * bus. As such, the address range is different and the buffer
 377          * address needs to be corrected.
 378          */
 379         paddr -= PHYS_OFFSET;
 380
 381         if (fb->format->is_yuv)
 382                 return sun4i_backend_update_yuv_buffer(backend, fb, paddr);
 383
 384         /* Write the 32 lower bits of the address (in bits) */
 385         lo_paddr = paddr << 3;
 386         DRM_DEBUG_DRIVER("Setting address lower bits to 0x%x\n", lo_paddr);
 387         regmap_write(backend->engine.regs,
 388                      SUN4I_BACKEND_LAYFB_L32ADD_REG(layer),
 389                      lo_paddr);
 390
 391         /* And the upper bits */
 392         hi_paddr = paddr >> 29;
 393         DRM_DEBUG_DRIVER("Setting address high bits to 0x%x\n", hi_paddr);
 394         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_LAYFB_H4ADD_REG,
 395                            SUN4I_BACKEND_LAYFB_H4ADD_MSK(layer),
 396                            SUN4I_BACKEND_LAYFB_H4ADD(layer, hi_paddr));
 397
 398         return 0;
 399 }
 400
 401 int sun4i_backend_update_layer_zpos(struct sun4i_backend *backend, int layer,
 402                                     struct drm_plane *plane)
 403 {
 404         struct drm_plane_state *state = plane->state;
 405         struct sun4i_layer_state *p_state = state_to_sun4i_layer_state(state);
 406         unsigned int priority = state->normalized_zpos;
 407         unsigned int pipe = p_state->pipe;
 408
 409         DRM_DEBUG_DRIVER("Setting layer %d's priority to %d and pipe %d\n",
 410                          layer, priority, pipe);
 411         regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
 412                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL_MASK |
 413                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PRISEL_MASK,
 414                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL(p_state->pipe) |
 415                            SUN4I_BACKEND_ATTCTL_REG0_LAY_PRISEL(priority));
 416
 417         return 0;
 418 }
 419
 420 static bool sun4i_backend_plane_uses_scaler(struct drm_plane_state *state)
 421 {
 422         u16 src_h = state->src_h >> 16;
 423         u16 src_w = state->src_w >> 16;
 424
 425         DRM_DEBUG_DRIVER("Input size %dx%d, output size %dx%d\n",
 426                          src_w, src_h, state->crtc_w, state->crtc_h);
 427
 428         if ((state->crtc_h != src_h) || (state->crtc_w != src_w))
 429                 return true;
 430
 431         return false;
 432 }
 433
 434 static bool sun4i_backend_plane_uses_frontend(struct drm_plane_state *state)
 435 {
 436         struct sun4i_layer *layer = plane_to_sun4i_layer(state->plane);
 437         struct sun4i_backend *backend = layer->backend;
 438
 439         if (IS_ERR(backend->frontend))
 440                 return false;
 441
 442         return sun4i_backend_plane_uses_scaler(state);
 443 }
 444
 445 static void sun4i_backend_atomic_begin(struct sunxi_engine *engine,
 446                                        struct drm_crtc_state *old_state)
 447 {
 448         u32 val;
 449
 450         WARN_ON(regmap_read_poll_timeout(engine->regs,
 451                                          SUN4I_BACKEND_REGBUFFCTL_REG,
 452                                          val, !(val & SUN4I_BACKEND_REGBUFFCTL_LOADCTL),
 453                                          100, 50000));
 454 }
 455
 456 static int sun4i_backend_atomic_check(struct sunxi_engine *engine,
 457                                       struct drm_crtc_state *crtc_state)
 458 {
 459         struct drm_plane_state *plane_states[SUN4I_BACKEND_NUM_LAYERS] = { 0 };
 460         struct drm_atomic_state *state = crtc_state->state;
 461         struct drm_device *drm = state->dev;
 462         struct drm_plane *plane;
 463         unsigned int num_planes = 0;
 464         unsigned int num_alpha_planes = 0;
 465         unsigned int num_frontend_planes = 0;
 466         unsigned int num_yuv_planes = 0;
 467         unsigned int current_pipe = 0;
 468         unsigned int i;
 469
 470         DRM_DEBUG_DRIVER("Starting checking our planes\n");
 471
 472         if (!crtc_state->planes_changed)
 473                 return 0;
 474
 475         drm_for_each_plane_mask(plane, drm, crtc_state->plane_mask) {
 476                 struct drm_plane_state *plane_state =
 477                         drm_atomic_get_plane_state(state, plane);
 478                 struct sun4i_layer_state *layer_state =
 479                         state_to_sun4i_layer_state(plane_state);
 480                 struct drm_framebuffer *fb = plane_state->fb;
 481                 struct drm_format_name_buf format_name;
 482
 483                 if (sun4i_backend_plane_uses_frontend(plane_state)) {
 484                         DRM_DEBUG_DRIVER("Using the frontend for plane %d\n",
 485                                          plane->index);
 486
 487                         layer_state->uses_frontend = true;
 488                         num_frontend_planes++;
 489                 } else {
 490                         layer_state->uses_frontend = false;
 491                 }
 492
 493                 DRM_DEBUG_DRIVER("Plane FB format is %s\n",
 494                                  drm_get_format_name(fb->format->format,
 495                                                      &format_name));
 496                 if (fb->format->has_alpha || (plane_state->alpha != DRM_BLEND_ALPHA_OPAQUE))
 497                         num_alpha_planes++;
 498
 499                 if (fb->format->is_yuv) {
 500                         DRM_DEBUG_DRIVER("Plane FB format is YUV\n");
 501                         num_yuv_planes++;
 502                 }
 503
 504                 DRM_DEBUG_DRIVER("Plane zpos is %d\n",
 505                                  plane_state->normalized_zpos);
 506
 507                 /* Sort our planes by Zpos */
 508                 plane_states[plane_state->normalized_zpos] = plane_state;
 509
 510                 num_planes++;
 511         }
 512
 513         /* All our planes were disabled, bail out */
 514         if (!num_planes)
 515                 return 0;
 516
 517         /*
 518          * The hardware is a bit unusual here.
 519          *
 520          * Even though it supports 4 layers, it does the composition
 521          * in two separate steps.
 522          *
 523          * The first one is assigning a layer to one of its two
 524          * pipes. If more that 1 layer is assigned to the same pipe,
 525          * and if pixels overlaps, the pipe will take the pixel from
 526          * the layer with the highest priority.
 527          *
 528          * The second step is the actual alpha blending, that takes
 529          * the two pipes as input, and uses the eventual alpha
 530          * component to do the transparency between the two.
 531          *
 532          * This two steps scenario makes us unable to guarantee a
 533          * robust alpha blending between the 4 layers in all
 534          * situations, since this means that we need to have one layer
 535          * with alpha at the lowest position of our two pipes.
 536          *
 537          * However, we cannot even do that, since the hardware has a
 538          * bug where the lowest plane of the lowest pipe (pipe 0,
 539          * priority 0), if it has any alpha, will discard the pixel
 540          * entirely and just display the pixels in the background
 541          * color (black by default).
 542          *
 543          * This means that we effectively have only three valid
 544          * configurations with alpha, all of them with the alpha being
 545          * on pipe1 with the lowest position, which can be 1, 2 or 3
 546          * depending on the number of planes and their zpos.
 547          */
 548         if (num_alpha_planes > SUN4I_BACKEND_NUM_ALPHA_LAYERS) {
 549                 DRM_DEBUG_DRIVER("Too many planes with alpha, rejecting...\n");
 550                 return -EINVAL;
 551         }
 552
 553         /* We can't have an alpha plane at the lowest position */
 554         if (plane_states[0]->fb->format->has_alpha ||
 555             (plane_states[0]->alpha != DRM_BLEND_ALPHA_OPAQUE))
 556                 return -EINVAL;
 557
 558         for (i = 1; i < num_planes; i++) {
 559                 struct drm_plane_state *p_state = plane_states[i];
 560                 struct drm_framebuffer *fb = p_state->fb;
 561                 struct sun4i_layer_state *s_state = state_to_sun4i_layer_state(p_state);
 562
 563                 /*
 564                  * The only alpha position is the lowest plane of the
 565                  * second pipe.
 566                  */
 567                 if (fb->format->has_alpha || (p_state->alpha != DRM_BLEND_ALPHA_OPAQUE))
 568                         current_pipe++;
 569
 570                 s_state->pipe = current_pipe;
 571         }
 572
 573         /* We can only have a single YUV plane at a time */
 574         if (num_yuv_planes > SUN4I_BACKEND_NUM_YUV_PLANES) {
 575                 DRM_DEBUG_DRIVER("Too many planes with YUV, rejecting...\n");
 576                 return -EINVAL;
 577         }
 578
 579         if (num_frontend_planes > SUN4I_BACKEND_NUM_FRONTEND_LAYERS) {
 580                 DRM_DEBUG_DRIVER("Too many planes going through the frontend, rejecting\n");
 581                 return -EINVAL;
 582         }
 583
 584         DRM_DEBUG_DRIVER("State valid with %u planes, %u alpha, %u video, %u YUV\n",
 585                          num_planes, num_alpha_planes, num_frontend_planes,
 586                          num_yuv_planes);
 587
 588         return 0;
 589 }
 590
 591 static void sun4i_backend_vblank_quirk(struct sunxi_engine *engine)
 592 {
 593         struct sun4i_backend *backend = engine_to_sun4i_backend(engine);
 594         struct sun4i_frontend *frontend = backend->frontend;
 595
 596         if (!frontend)
 597                 return;
 598
 599         /*
 600          * In a teardown scenario with the frontend involved, we have
 601          * to keep the frontend enabled until the next vblank, and
 602          * only then disable it.
 603          *
 604          * This is due to the fact that the backend will not take into
 605          * account the new configuration (with the plane that used to
 606          * be fed by the frontend now disabled) until we write to the
 607          * commit bit and the hardware fetches the new configuration
 608          * during the next vblank.
 609          *
 610          * So we keep the frontend around in order to prevent any
 611          * visual artifacts.
 612          */
 613         spin_lock(&backend->frontend_lock);
 614         if (backend->frontend_teardown) {
 615                 sun4i_frontend_exit(frontend);
 616                 backend->frontend_teardown = false;
 617         }
 618         spin_unlock(&backend->frontend_lock);
 619 };
 620
 621 static int sun4i_backend_init_sat(struct device *dev) {
 622         struct sun4i_backend *backend = dev_get_drvdata(dev);
 623         int ret;
 624
 625         backend->sat_reset = devm_reset_control_get(dev, "sat");
 626         if (IS_ERR(backend->sat_reset)) {
 627                 dev_err(dev, "Couldn't get the SAT reset line\n");
 628                 return PTR_ERR(backend->sat_reset);
 629         }
 630
 631         ret = reset_control_deassert(backend->sat_reset);
 632         if (ret) {
 633                 dev_err(dev, "Couldn't deassert the SAT reset line\n");
 634                 return ret;
 635         }
 636
 637         backend->sat_clk = devm_clk_get(dev, "sat");
 638         if (IS_ERR(backend->sat_clk)) {
 639                 dev_err(dev, "Couldn't get our SAT clock\n");
 640                 ret = PTR_ERR(backend->sat_clk);
 641                 goto err_assert_reset;
 642         }
 643
 644         ret = clk_prepare_enable(backend->sat_clk);
 645         if (ret) {
 646                 dev_err(dev, "Couldn't enable the SAT clock\n");
 647                 return ret;
 648         }
 649
 650         return 0;
 651
 652 err_assert_reset:
 653         reset_control_assert(backend->sat_reset);
 654         return ret;
 655 }
 656
 657 static int sun4i_backend_free_sat(struct device *dev) {
 658         struct sun4i_backend *backend = dev_get_drvdata(dev);
 659
 660         clk_disable_unprepare(backend->sat_clk);
 661         reset_control_assert(backend->sat_reset);
 662
 663         return 0;
 664 }
 665
 666 /*
 667  * The display backend can take video output from the display frontend, or
 668  * the display enhancement unit on the A80, as input for one it its layers.
 669  * This relationship within the display pipeline is encoded in the device
 670  * tree with of_graph, and we use it here to figure out which backend, if
 671  * there are 2 or more, we are currently probing. The number would be in
 672  * the "reg" property of the upstream output port endpoint.
 673  */
 674 static int sun4i_backend_of_get_id(struct device_node *node)
 675 {
 676         struct device_node *port, *ep;
 677         int ret = -EINVAL;
 678
 679         /* input is port 0 */
 680         port = of_graph_get_port_by_id(node, 0);
 681         if (!port)
 682                 return -EINVAL;
 683
 684         /* try finding an upstream endpoint */
 685         for_each_available_child_of_node(port, ep) {
 686                 struct device_node *remote;
 687                 u32 reg;
 688
 689                 remote = of_graph_get_remote_endpoint(ep);
 690                 if (!remote)
 691                         continue;
 692
 693                 ret = of_property_read_u32(remote, "reg", &reg);
 694                 if (ret)
 695                         continue;
 696
 697                 ret = reg;
 698         }
 699
 700         of_node_put(port);
 701
 702         return ret;
 703 }
 704
 705 /* TODO: This needs to take multiple pipelines into account */
 706 static struct sun4i_frontend *sun4i_backend_find_frontend(struct sun4i_drv *drv,
 707                                                           struct device_node *node)
 708 {
 709         struct device_node *port, *ep, *remote;
 710         struct sun4i_frontend *frontend;
 711
 712         port = of_graph_get_port_by_id(node, 0);
 713         if (!port)
 714                 return ERR_PTR(-EINVAL);
 715
 716         for_each_available_child_of_node(port, ep) {
 717                 remote = of_graph_get_remote_port_parent(ep);
 718                 if (!remote)
 719                         continue;
 720                 of_node_put(remote);
 721
 722                 /* does this node match any registered engines? */
 723                 list_for_each_entry(frontend, &drv->frontend_list, list) {
 724                         if (remote == frontend->node) {
 725                                 of_node_put(port);
 726                                 of_node_put(ep);
 727                                 return frontend;
 728                         }
 729                 }
 730         }
 731         of_node_put(port);
 732         return ERR_PTR(-EINVAL);
 733 }
 734
 735 static const struct sunxi_engine_ops sun4i_backend_engine_ops = {
 736         .atomic_begin                   = sun4i_backend_atomic_begin,
 737         .atomic_check                   = sun4i_backend_atomic_check,
 738         .commit                         = sun4i_backend_commit,
 739         .layers_init                    = sun4i_layers_init,
 740         .apply_color_correction         = sun4i_backend_apply_color_correction,
 741         .disable_color_correction       = sun4i_backend_disable_color_correction,
 742         .vblank_quirk                   = sun4i_backend_vblank_quirk,
 743 };
 744
 745 static struct regmap_config sun4i_backend_regmap_config = {
 746         .reg_bits       = 32,
 747         .val_bits       = 32,
 748         .reg_stride     = 4,
 749         .max_register   = 0x5800,
 750 };
 751
 752 static int sun4i_backend_bind(struct device *dev, struct device *master,
 753                               void *data)
 754 {
 755         struct platform_device *pdev = to_platform_device(dev);
 756         struct drm_device *drm = data;
 757         struct sun4i_drv *drv = drm->dev_private;
 758         struct sun4i_backend *backend;
 759         const struct sun4i_backend_quirks *quirks;
 760         struct resource *res;
 761         void __iomem *regs;
 762         int i, ret;
 763
 764         backend = devm_kzalloc(dev, sizeof(*backend), GFP_KERNEL);
 765         if (!backend)
 766                 return -ENOMEM;
 767         dev_set_drvdata(dev, backend);
 768         spin_lock_init(&backend->frontend_lock);
 769
 770         backend->engine.node = dev->of_node;
 771         backend->engine.ops = &sun4i_backend_engine_ops;
 772         backend->engine.id = sun4i_backend_of_get_id(dev->of_node);
 773         if (backend->engine.id < 0)
 774                 return backend->engine.id;
 775
 776         backend->frontend = sun4i_backend_find_frontend(drv, dev->of_node);
 777         if (IS_ERR(backend->frontend))
 778                 dev_warn(dev, "Couldn't find matching frontend, frontend features disabled\n");
 779
 780         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 781         regs = devm_ioremap_resource(dev, res);
 782         if (IS_ERR(regs))
 783                 return PTR_ERR(regs);
 784
 785         backend->reset = devm_reset_control_get(dev, NULL);
 786         if (IS_ERR(backend->reset)) {
 787                 dev_err(dev, "Couldn't get our reset line\n");
 788                 return PTR_ERR(backend->reset);
 789         }
 790
 791         ret = reset_control_deassert(backend->reset);
 792         if (ret) {
 793                 dev_err(dev, "Couldn't deassert our reset line\n");
 794                 return ret;
 795         }
 796
 797         backend->bus_clk = devm_clk_get(dev, "ahb");
 798         if (IS_ERR(backend->bus_clk)) {
 799                 dev_err(dev, "Couldn't get the backend bus clock\n");
 800                 ret = PTR_ERR(backend->bus_clk);
 801                 goto err_assert_reset;
 802         }
 803         clk_prepare_enable(backend->bus_clk);
 804
 805         backend->mod_clk = devm_clk_get(dev, "mod");
 806         if (IS_ERR(backend->mod_clk)) {
 807                 dev_err(dev, "Couldn't get the backend module clock\n");
 808                 ret = PTR_ERR(backend->mod_clk);
 809                 goto err_disable_bus_clk;
 810         }
 811         clk_prepare_enable(backend->mod_clk);
 812
 813         backend->ram_clk = devm_clk_get(dev, "ram");
 814         if (IS_ERR(backend->ram_clk)) {
 815                 dev_err(dev, "Couldn't get the backend RAM clock\n");
 816                 ret = PTR_ERR(backend->ram_clk);
 817                 goto err_disable_mod_clk;
 818         }
 819         clk_prepare_enable(backend->ram_clk);
 820
 821         if (of_device_is_compatible(dev->of_node,
 822                                     "allwinner,sun8i-a33-display-backend")) {
 823                 ret = sun4i_backend_init_sat(dev);
 824                 if (ret) {
 825                         dev_err(dev, "Couldn't init SAT resources\n");
 826                         goto err_disable_ram_clk;
 827                 }
 828         }
 829
 830         backend->engine.regs = devm_regmap_init_mmio(dev, regs,
 831                                                      &sun4i_backend_regmap_config);
 832         if (IS_ERR(backend->engine.regs)) {
 833                 dev_err(dev, "Couldn't create the backend regmap\n");
 834                 return PTR_ERR(backend->engine.regs);
 835         }
 836
 837         list_add_tail(&backend->engine.list, &drv->engine_list);
 838
 839         /*
 840          * Many of the backend's layer configuration registers have
 841          * undefined default values. This poses a risk as we use
 842          * regmap_update_bits in some places, and don't overwrite
 843          * the whole register.
 844          *
 845          * Clear the registers here to have something predictable.
 846          */
 847         for (i = 0x800; i < 0x1000; i += 4)
 848                 regmap_write(backend->engine.regs, i, 0);
 849
 850         /* Disable registers autoloading */
 851         regmap_write(backend->engine.regs, SUN4I_BACKEND_REGBUFFCTL_REG,
 852                      SUN4I_BACKEND_REGBUFFCTL_AUTOLOAD_DIS);
 853
 854         /* Enable the backend */
 855         regmap_write(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
 856                      SUN4I_BACKEND_MODCTL_DEBE_EN |
 857                      SUN4I_BACKEND_MODCTL_START_CTL);
 858
 859         /* Set output selection if needed */
 860         quirks = of_device_get_match_data(dev);
 861         if (quirks->needs_output_muxing) {
 862                 /*
 863                  * We assume there is no dynamic muxing of backends
 864                  * and TCONs, so we select the backend with same ID.
 865                  *
 866                  * While dynamic selection might be interesting, since
 867                  * the CRTC is tied to the TCON, while the layers are
 868                  * tied to the backends, this means, we will need to
 869                  * switch between groups of layers. There might not be
 870                  * a way to represent this constraint in DRM.
 871                  */
 872                 regmap_update_bits(backend->engine.regs,
 873                                    SUN4I_BACKEND_MODCTL_REG,
 874                                    SUN4I_BACKEND_MODCTL_OUT_SEL,
 875                                    (backend->engine.id
 876                                     ? SUN4I_BACKEND_MODCTL_OUT_LCD1
 877                                     : SUN4I_BACKEND_MODCTL_OUT_LCD0));
 878         }
 879
 880         return 0;
 881
 882 err_disable_ram_clk:
 883         clk_disable_unprepare(backend->ram_clk);
 884 err_disable_mod_clk:
 885         clk_disable_unprepare(backend->mod_clk);
 886 err_disable_bus_clk:
 887         clk_disable_unprepare(backend->bus_clk);
 888 err_assert_reset:
 889         reset_control_assert(backend->reset);
 890         return ret;
 891 }
 892
 893 static void sun4i_backend_unbind(struct device *dev, struct device *master,
 894                                  void *data)
 895 {
 896         struct sun4i_backend *backend = dev_get_drvdata(dev);
 897
 898         list_del(&backend->engine.list);
 899
 900         if (of_device_is_compatible(dev->of_node,
 901                                     "allwinner,sun8i-a33-display-backend"))
 902                 sun4i_backend_free_sat(dev);
 903
 904         clk_disable_unprepare(backend->ram_clk);
 905         clk_disable_unprepare(backend->mod_clk);
 906         clk_disable_unprepare(backend->bus_clk);
 907         reset_control_assert(backend->reset);
 908 }
 909
 910 static const struct component_ops sun4i_backend_ops = {
 911         .bind   = sun4i_backend_bind,
 912         .unbind = sun4i_backend_unbind,
 913 };
 914
 915 static int sun4i_backend_probe(struct platform_device *pdev)
 916 {
 917         return component_add(&pdev->dev, &sun4i_backend_ops);
 918 }
 919
 920 static int sun4i_backend_remove(struct platform_device *pdev)
 921 {
 922         component_del(&pdev->dev, &sun4i_backend_ops);
 923
 924         return 0;
 925 }
 926
 927 static const struct sun4i_backend_quirks sun4i_backend_quirks = {
 928         .needs_output_muxing = true,
 929 };
 930
 931 static const struct sun4i_backend_quirks sun5i_backend_quirks = {
 932 };
 933
 934 static const struct sun4i_backend_quirks sun6i_backend_quirks = {
 935 };
 936
 937 static const struct sun4i_backend_quirks sun7i_backend_quirks = {
 938         .needs_output_muxing = true,
 939 };
 940
 941 static const struct sun4i_backend_quirks sun8i_a33_backend_quirks = {
 942 };
 943
 944 static const struct sun4i_backend_quirks sun9i_backend_quirks = {
 945 };
 946
 947 static const struct of_device_id sun4i_backend_of_table[] = {
 948         {
 949                 .compatible = "allwinner,sun4i-a10-display-backend",
 950                 .data = &sun4i_backend_quirks,
 951         },
 952         {
 953                 .compatible = "allwinner,sun5i-a13-display-backend",
 954                 .data = &sun5i_backend_quirks,
 955         },
 956         {
 957                 .compatible = "allwinner,sun6i-a31-display-backend",
 958                 .data = &sun6i_backend_quirks,
 959         },
 960         {
 961                 .compatible = "allwinner,sun7i-a20-display-backend",
 962                 .data = &sun7i_backend_quirks,
 963         },
 964         {
 965                 .compatible = "allwinner,sun8i-a33-display-backend",
 966                 .data = &sun8i_a33_backend_quirks,
 967         },
 968         {
 969                 .compatible = "allwinner,sun9i-a80-display-backend",
 970                 .data = &sun9i_backend_quirks,
 971         },
 972         { }
 973 };
 974 MODULE_DEVICE_TABLE(of, sun4i_backend_of_table);
 975
 976 static struct platform_driver sun4i_backend_platform_driver = {
 977         .probe          = sun4i_backend_probe,
 978         .remove         = sun4i_backend_remove,
 979         .driver         = {
 980                 .name           = "sun4i-backend",
 981                 .of_match_table = sun4i_backend_of_table,
 982         },
 983 };
 984 module_platform_driver(sun4i_backend_platform_driver);
 985
 986 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 987 MODULE_DESCRIPTION("Allwinner A10 Display Backend Driver");
 988 MODULE_LICENSE("GPL");