drivers/gpu/drm/pl111/pl111_display.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * (C) COPYRIGHT 2012-2013 ARM Limited. All rights reserved.
   4  *
   5  * Parts of this file were based on sources as follows:
   6  *
   7  * Copyright (c) 2006-2008 Intel Corporation
   8  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
   9  * Copyright (C) 2011 Texas Instruments
  10  */
  11
  12 #include <linux/amba/clcd-regs.h>
  13 #include <linux/clk.h>
  14 #include <linux/delay.h>
  15 #include <linux/version.h>
  16 #include <linux/dma-buf.h>
  17 #include <linux/of_graph.h>
  18
  19 #include <drm/drm_fb_cma_helper.h>
  20 #include <drm/drm_fourcc.h>
  21 #include <drm/drm_gem_cma_helper.h>
  22 #include <drm/drm_gem_framebuffer_helper.h>
  23 #include <drm/drm_vblank.h>
  24
  25 #include "pl111_drm.h"
  26
  27 irqreturn_t pl111_irq(int irq, void *data)
  28 {
  29         struct pl111_drm_dev_private *priv = data;
  30         u32 irq_stat;
  31         irqreturn_t status = IRQ_NONE;
  32
  33         irq_stat = readl(priv->regs + CLCD_PL111_MIS);
  34
  35         if (!irq_stat)
  36                 return IRQ_NONE;
  37
  38         if (irq_stat & CLCD_IRQ_NEXTBASE_UPDATE) {
  39                 drm_crtc_handle_vblank(&priv->pipe.crtc);
  40
  41                 status = IRQ_HANDLED;
  42         }
  43
  44         /* Clear the interrupt once done */
  45         writel(irq_stat, priv->regs + CLCD_PL111_ICR);
  46
  47         return status;
  48 }
  49
  50 static enum drm_mode_status
  51 pl111_mode_valid(struct drm_crtc *crtc,
  52                  const struct drm_display_mode *mode)
  53 {
  54         struct drm_device *drm = crtc->dev;
  55         struct pl111_drm_dev_private *priv = drm->dev_private;
  56         u32 cpp = priv->variant->fb_bpp / 8;
  57         u64 bw;
  58
  59         /*
  60          * We use the pixelclock to also account for interlaced modes, the
  61          * resulting bandwidth is in bytes per second.
  62          */
  63         bw = mode->clock * 1000ULL; /* In Hz */
  64         bw = bw * mode->hdisplay * mode->vdisplay * cpp;
  65         bw = div_u64(bw, mode->htotal * mode->vtotal);
  66
  67         /*
  68          * If no bandwidth constraints, anything goes, else
  69          * check if we are too fast.
  70          */
  71         if (priv->memory_bw && (bw > priv->memory_bw)) {
  72                 DRM_DEBUG_KMS("%d x %d @ %d Hz, %d cpp, bw %llu too fast\n",
  73                               mode->hdisplay, mode->vdisplay,
  74                               mode->clock * 1000, cpp, bw);
  75
  76                 return MODE_BAD;
  77         }
  78         DRM_DEBUG_KMS("%d x %d @ %d Hz, %d cpp, bw %llu bytes/s OK\n",
  79                       mode->hdisplay, mode->vdisplay,
  80                       mode->clock * 1000, cpp, bw);
  81
  82         return MODE_OK;
  83 }
  84
  85 static int pl111_display_check(struct drm_simple_display_pipe *pipe,
  86                                struct drm_plane_state *pstate,
  87                                struct drm_crtc_state *cstate)
  88 {
  89         const struct drm_display_mode *mode = &cstate->mode;
  90         struct drm_framebuffer *old_fb = pipe->plane.state->fb;
  91         struct drm_framebuffer *fb = pstate->fb;
  92
  93         if (mode->hdisplay % 16)
  94                 return -EINVAL;
  95
  96         if (fb) {
  97                 u32 offset = drm_fb_cma_get_gem_addr(fb, pstate, 0);
  98
  99                 /* FB base address must be dword aligned. */
 100                 if (offset & 3)
 101                         return -EINVAL;
 102
 103                 /* There's no pitch register -- the mode's hdisplay
 104                  * controls it.
 105                  */
 106                 if (fb->pitches[0] != mode->hdisplay * fb->format->cpp[0])
 107                         return -EINVAL;
 108
 109                 /* We can't change the FB format in a flicker-free
 110                  * manner (and only update it during CRTC enable).
 111                  */
 112                 if (old_fb && old_fb->format != fb->format)
 113                         cstate->mode_changed = true;
 114         }
 115
 116         return 0;
 117 }
 118
 119 static void pl111_display_enable(struct drm_simple_display_pipe *pipe,
 120                                  struct drm_crtc_state *cstate,
 121                                  struct drm_plane_state *plane_state)
 122 {
 123         struct drm_crtc *crtc = &pipe->crtc;
 124         struct drm_plane *plane = &pipe->plane;
 125         struct drm_device *drm = crtc->dev;
 126         struct pl111_drm_dev_private *priv = drm->dev_private;
 127         const struct drm_display_mode *mode = &cstate->mode;
 128         struct drm_framebuffer *fb = plane->state->fb;
 129         struct drm_connector *connector = priv->connector;
 130         struct drm_bridge *bridge = priv->bridge;
 131         bool grayscale = false;
 132         u32 cntl;
 133         u32 ppl, hsw, hfp, hbp;
 134         u32 lpp, vsw, vfp, vbp;
 135         u32 cpl, tim2;
 136         int ret;
 137
 138         ret = clk_set_rate(priv->clk, mode->clock * 1000);
 139         if (ret) {
 140                 dev_err(drm->dev,
 141                         "Failed to set pixel clock rate to %d: %d\n",
 142                         mode->clock * 1000, ret);
 143         }
 144
 145         clk_prepare_enable(priv->clk);
 146
 147         ppl = (mode->hdisplay / 16) - 1;
 148         hsw = mode->hsync_end - mode->hsync_start - 1;
 149         hfp = mode->hsync_start - mode->hdisplay - 1;
 150         hbp = mode->htotal - mode->hsync_end - 1;
 151
 152         lpp = mode->vdisplay - 1;
 153         vsw = mode->vsync_end - mode->vsync_start - 1;
 154         vfp = mode->vsync_start - mode->vdisplay;
 155         vbp = mode->vtotal - mode->vsync_end;
 156
 157         cpl = mode->hdisplay - 1;
 158
 159         writel((ppl << 2) |
 160                (hsw << 8) |
 161                (hfp << 16) |
 162                (hbp << 24),
 163                priv->regs + CLCD_TIM0);
 164         writel(lpp |
 165                (vsw << 10) |
 166                (vfp << 16) |
 167                (vbp << 24),
 168                priv->regs + CLCD_TIM1);
 169
 170         spin_lock(&priv->tim2_lock);
 171
 172         tim2 = readl(priv->regs + CLCD_TIM2);
 173         tim2 &= (TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
 174
 175         if (priv->variant->broken_clockdivider)
 176                 tim2 |= TIM2_BCD;
 177
 178         if (mode->flags & DRM_MODE_FLAG_NHSYNC)
 179                 tim2 |= TIM2_IHS;
 180
 181         if (mode->flags & DRM_MODE_FLAG_NVSYNC)
 182                 tim2 |= TIM2_IVS;
 183
 184         if (connector) {
 185                 if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
 186                         tim2 |= TIM2_IOE;
 187
 188                 if (connector->display_info.bus_flags &
 189                     DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
 190                         tim2 |= TIM2_IPC;
 191
 192                 if (connector->display_info.num_bus_formats == 1 &&
 193                     connector->display_info.bus_formats[0] ==
 194                     MEDIA_BUS_FMT_Y8_1X8)
 195                         grayscale = true;
 196
 197                 /*
 198                  * The AC pin bias frequency is set to max count when using
 199                  * grayscale so at least once in a while we will reverse
 200                  * polarity and get rid of any DC built up that could
 201                  * damage the display.
 202                  */
 203                 if (grayscale)
 204                         tim2 |= TIM2_ACB_MASK;
 205         }
 206
 207         if (bridge) {
 208                 const struct drm_bridge_timings *btimings = bridge->timings;
 209
 210                 /*
 211                  * Here is when things get really fun. Sometimes the bridge
 212                  * timings are such that the signal out from PL11x is not
 213                  * stable before the receiving bridge (such as a dumb VGA DAC
 214                  * or similar) samples it. If that happens, we compensate by
 215                  * the only method we have: output the data on the opposite
 216                  * edge of the clock so it is for sure stable when it gets
 217                  * sampled.
 218                  *
 219                  * The PL111 manual does not contain proper timining diagrams
 220                  * or data for these details, but we know from experiments
 221                  * that the setup time is more than 3000 picoseconds (3 ns).
 222                  * If we have a bridge that requires the signal to be stable
 223                  * earlier than 3000 ps before the clock pulse, we have to
 224                  * output the data on the opposite edge to avoid flicker.
 225                  */
 226                 if (btimings && btimings->setup_time_ps >= 3000)
 227                         tim2 ^= TIM2_IPC;
 228         }
 229
 230         tim2 |= cpl << 16;
 231         writel(tim2, priv->regs + CLCD_TIM2);
 232         spin_unlock(&priv->tim2_lock);
 233
 234         writel(0, priv->regs + CLCD_TIM3);
 235
 236         /*
 237          * Detect grayscale bus format. We do not support a grayscale mode
 238          * toward userspace, instead we expose an RGB24 buffer and then the
 239          * hardware will activate its grayscaler to convert to the grayscale
 240          * format.
 241          */
 242         if (grayscale)
 243                 cntl = CNTL_LCDEN | CNTL_LCDMONO8;
 244         else
 245                 /* Else we assume TFT display */
 246                 cntl = CNTL_LCDEN | CNTL_LCDTFT | CNTL_LCDVCOMP(1);
 247
 248         /* On the ST Micro variant, assume all 24 bits are connected */
 249         if (priv->variant->st_bitmux_control)
 250                 cntl |= CNTL_ST_CDWID_24;
 251
 252         /*
 253          * Note that the the ARM hardware's format reader takes 'r' from
 254          * the low bit, while DRM formats list channels from high bit
 255          * to low bit as you read left to right. The ST Micro version of
 256          * the PL110 (LCDC) however uses the standard DRM format.
 257          */
 258         switch (fb->format->format) {
 259         case DRM_FORMAT_BGR888:
 260                 /* Only supported on the ST Micro variant */
 261                 if (priv->variant->st_bitmux_control)
 262                         cntl |= CNTL_ST_LCDBPP24_PACKED | CNTL_BGR;
 263                 break;
 264         case DRM_FORMAT_RGB888:
 265                 /* Only supported on the ST Micro variant */
 266                 if (priv->variant->st_bitmux_control)
 267                         cntl |= CNTL_ST_LCDBPP24_PACKED;
 268                 break;
 269         case DRM_FORMAT_ABGR8888:
 270         case DRM_FORMAT_XBGR8888:
 271                 if (priv->variant->st_bitmux_control)
 272                         cntl |= CNTL_LCDBPP24 | CNTL_BGR;
 273                 else
 274                         cntl |= CNTL_LCDBPP24;
 275                 break;
 276         case DRM_FORMAT_ARGB8888:
 277         case DRM_FORMAT_XRGB8888:
 278                 if (priv->variant->st_bitmux_control)
 279                         cntl |= CNTL_LCDBPP24;
 280                 else
 281                         cntl |= CNTL_LCDBPP24 | CNTL_BGR;
 282                 break;
 283         case DRM_FORMAT_BGR565:
 284                 if (priv->variant->is_pl110)
 285                         cntl |= CNTL_LCDBPP16;
 286                 else if (priv->variant->st_bitmux_control)
 287                         cntl |= CNTL_LCDBPP16 | CNTL_ST_1XBPP_565 | CNTL_BGR;
 288                 else
 289                         cntl |= CNTL_LCDBPP16_565;
 290                 break;
 291         case DRM_FORMAT_RGB565:
 292                 if (priv->variant->is_pl110)
 293                         cntl |= CNTL_LCDBPP16 | CNTL_BGR;
 294                 else if (priv->variant->st_bitmux_control)
 295                         cntl |= CNTL_LCDBPP16 | CNTL_ST_1XBPP_565;
 296                 else
 297                         cntl |= CNTL_LCDBPP16_565 | CNTL_BGR;
 298                 break;
 299         case DRM_FORMAT_ABGR1555:
 300         case DRM_FORMAT_XBGR1555:
 301                 cntl |= CNTL_LCDBPP16;
 302                 if (priv->variant->st_bitmux_control)
 303                         cntl |= CNTL_ST_1XBPP_5551 | CNTL_BGR;
 304                 break;
 305         case DRM_FORMAT_ARGB1555:
 306         case DRM_FORMAT_XRGB1555:
 307                 cntl |= CNTL_LCDBPP16;
 308                 if (priv->variant->st_bitmux_control)
 309                         cntl |= CNTL_ST_1XBPP_5551;
 310                 else
 311                         cntl |= CNTL_BGR;
 312                 break;
 313         case DRM_FORMAT_ABGR4444:
 314         case DRM_FORMAT_XBGR4444:
 315                 cntl |= CNTL_LCDBPP16_444;
 316                 if (priv->variant->st_bitmux_control)
 317                         cntl |= CNTL_ST_1XBPP_444 | CNTL_BGR;
 318                 break;
 319         case DRM_FORMAT_ARGB4444:
 320         case DRM_FORMAT_XRGB4444:
 321                 cntl |= CNTL_LCDBPP16_444;
 322                 if (priv->variant->st_bitmux_control)
 323                         cntl |= CNTL_ST_1XBPP_444;
 324                 else
 325                         cntl |= CNTL_BGR;
 326                 break;
 327         default:
 328                 WARN_ONCE(true, "Unknown FB format 0x%08x\n",
 329                           fb->format->format);
 330                 break;
 331         }
 332
 333         /* The PL110 in Integrator/Versatile does the BGR routing externally */
 334         if (priv->variant->external_bgr)
 335                 cntl &= ~CNTL_BGR;
 336
 337         /* Power sequence: first enable and chill */
 338         writel(cntl, priv->regs + priv->ctrl);
 339
 340         /*
 341          * We expect this delay to stabilize the contrast
 342          * voltage Vee as stipulated by the manual
 343          */
 344         msleep(20);
 345
 346         if (priv->variant_display_enable)
 347                 priv->variant_display_enable(drm, fb->format->format);
 348
 349         /* Power Up */
 350         cntl |= CNTL_LCDPWR;
 351         writel(cntl, priv->regs + priv->ctrl);
 352
 353         if (!priv->variant->broken_vblank)
 354                 drm_crtc_vblank_on(crtc);
 355 }
 356
 357 void pl111_display_disable(struct drm_simple_display_pipe *pipe)
 358 {
 359         struct drm_crtc *crtc = &pipe->crtc;
 360         struct drm_device *drm = crtc->dev;
 361         struct pl111_drm_dev_private *priv = drm->dev_private;
 362         u32 cntl;
 363
 364         if (!priv->variant->broken_vblank)
 365                 drm_crtc_vblank_off(crtc);
 366
 367         /* Power Down */
 368         cntl = readl(priv->regs + priv->ctrl);
 369         if (cntl & CNTL_LCDPWR) {
 370                 cntl &= ~CNTL_LCDPWR;
 371                 writel(cntl, priv->regs + priv->ctrl);
 372         }
 373
 374         /*
 375          * We expect this delay to stabilize the contrast voltage Vee as
 376          * stipulated by the manual
 377          */
 378         msleep(20);
 379
 380         if (priv->variant_display_disable)
 381                 priv->variant_display_disable(drm);
 382
 383         /* Disable */
 384         writel(0, priv->regs + priv->ctrl);
 385
 386         clk_disable_unprepare(priv->clk);
 387 }
 388
 389 static void pl111_display_update(struct drm_simple_display_pipe *pipe,
 390                                  struct drm_plane_state *old_pstate)
 391 {
 392         struct drm_crtc *crtc = &pipe->crtc;
 393         struct drm_device *drm = crtc->dev;
 394         struct pl111_drm_dev_private *priv = drm->dev_private;
 395         struct drm_pending_vblank_event *event = crtc->state->event;
 396         struct drm_plane *plane = &pipe->plane;
 397         struct drm_plane_state *pstate = plane->state;
 398         struct drm_framebuffer *fb = pstate->fb;
 399
 400         if (fb) {
 401                 u32 addr = drm_fb_cma_get_gem_addr(fb, pstate, 0);
 402
 403                 writel(addr, priv->regs + CLCD_UBAS);
 404         }
 405
 406         if (event) {
 407                 crtc->state->event = NULL;
 408
 409                 spin_lock_irq(&crtc->dev->event_lock);
 410                 if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
 411                         drm_crtc_arm_vblank_event(crtc, event);
 412                 else
 413                         drm_crtc_send_vblank_event(crtc, event);
 414                 spin_unlock_irq(&crtc->dev->event_lock);
 415         }
 416 }
 417
 418 static int pl111_display_enable_vblank(struct drm_simple_display_pipe *pipe)
 419 {
 420         struct drm_crtc *crtc = &pipe->crtc;
 421         struct drm_device *drm = crtc->dev;
 422         struct pl111_drm_dev_private *priv = drm->dev_private;
 423
 424         writel(CLCD_IRQ_NEXTBASE_UPDATE, priv->regs + priv->ienb);
 425
 426         return 0;
 427 }
 428
 429 static void pl111_display_disable_vblank(struct drm_simple_display_pipe *pipe)
 430 {
 431         struct drm_crtc *crtc = &pipe->crtc;
 432         struct drm_device *drm = crtc->dev;
 433         struct pl111_drm_dev_private *priv = drm->dev_private;
 434
 435         writel(0, priv->regs + priv->ienb);
 436 }
 437
 438 static struct drm_simple_display_pipe_funcs pl111_display_funcs = {
 439         .mode_valid = pl111_mode_valid,
 440         .check = pl111_display_check,
 441         .enable = pl111_display_enable,
 442         .disable = pl111_display_disable,
 443         .update = pl111_display_update,
 444         .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
 445 };
 446
 447 static int pl111_clk_div_choose_div(struct clk_hw *hw, unsigned long rate,
 448                                     unsigned long *prate, bool set_parent)
 449 {
 450         int best_div = 1, div;
 451         struct clk_hw *parent = clk_hw_get_parent(hw);
 452         unsigned long best_prate = 0;
 453         unsigned long best_diff = ~0ul;
 454         int max_div = (1 << (TIM2_PCD_LO_BITS + TIM2_PCD_HI_BITS)) - 1;
 455
 456         for (div = 1; div < max_div; div++) {
 457                 unsigned long this_prate, div_rate, diff;
 458
 459                 if (set_parent)
 460                         this_prate = clk_hw_round_rate(parent, rate * div);
 461                 else
 462                         this_prate = *prate;
 463                 div_rate = DIV_ROUND_UP_ULL(this_prate, div);
 464                 diff = abs(rate - div_rate);
 465
 466                 if (diff < best_diff) {
 467                         best_div = div;
 468                         best_diff = diff;
 469                         best_prate = this_prate;
 470                 }
 471         }
 472
 473         *prate = best_prate;
 474         return best_div;
 475 }
 476
 477 static long pl111_clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
 478                                      unsigned long *prate)
 479 {
 480         int div = pl111_clk_div_choose_div(hw, rate, prate, true);
 481
 482         return DIV_ROUND_UP_ULL(*prate, div);
 483 }
 484
 485 static unsigned long pl111_clk_div_recalc_rate(struct clk_hw *hw,
 486                                                unsigned long prate)
 487 {
 488         struct pl111_drm_dev_private *priv =
 489                 container_of(hw, struct pl111_drm_dev_private, clk_div);
 490         u32 tim2 = readl(priv->regs + CLCD_TIM2);
 491         int div;
 492
 493         if (tim2 & TIM2_BCD)
 494                 return prate;
 495
 496         div = tim2 & TIM2_PCD_LO_MASK;
 497         div |= (tim2 & TIM2_PCD_HI_MASK) >>
 498                 (TIM2_PCD_HI_SHIFT - TIM2_PCD_LO_BITS);
 499         div += 2;
 500
 501         return DIV_ROUND_UP_ULL(prate, div);
 502 }
 503
 504 static int pl111_clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
 505                                   unsigned long prate)
 506 {
 507         struct pl111_drm_dev_private *priv =
 508                 container_of(hw, struct pl111_drm_dev_private, clk_div);
 509         int div = pl111_clk_div_choose_div(hw, rate, &prate, false);
 510         u32 tim2;
 511
 512         spin_lock(&priv->tim2_lock);
 513         tim2 = readl(priv->regs + CLCD_TIM2);
 514         tim2 &= ~(TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
 515
 516         if (div == 1) {
 517                 tim2 |= TIM2_BCD;
 518         } else {
 519                 div -= 2;
 520                 tim2 |= div & TIM2_PCD_LO_MASK;
 521                 tim2 |= (div >> TIM2_PCD_LO_BITS) << TIM2_PCD_HI_SHIFT;
 522         }
 523
 524         writel(tim2, priv->regs + CLCD_TIM2);
 525         spin_unlock(&priv->tim2_lock);
 526
 527         return 0;
 528 }
 529
 530 static const struct clk_ops pl111_clk_div_ops = {
 531         .recalc_rate = pl111_clk_div_recalc_rate,
 532         .round_rate = pl111_clk_div_round_rate,
 533         .set_rate = pl111_clk_div_set_rate,
 534 };
 535
 536 static int
 537 pl111_init_clock_divider(struct drm_device *drm)
 538 {
 539         struct pl111_drm_dev_private *priv = drm->dev_private;
 540         struct clk *parent = devm_clk_get(drm->dev, "clcdclk");
 541         struct clk_hw *div = &priv->clk_div;
 542         const char *parent_name;
 543         struct clk_init_data init = {
 544                 .name = "pl111_div",
 545                 .ops = &pl111_clk_div_ops,
 546                 .parent_names = &parent_name,
 547                 .num_parents = 1,
 548                 .flags = CLK_SET_RATE_PARENT,
 549         };
 550         int ret;
 551
 552         if (IS_ERR(parent)) {
 553                 dev_err(drm->dev, "CLCD: unable to get clcdclk.\n");
 554                 return PTR_ERR(parent);
 555         }
 556
 557         spin_lock_init(&priv->tim2_lock);
 558
 559         /* If the clock divider is broken, use the parent directly */
 560         if (priv->variant->broken_clockdivider) {
 561                 priv->clk = parent;
 562                 return 0;
 563         }
 564         parent_name = __clk_get_name(parent);
 565         div->init = &init;
 566
 567         ret = devm_clk_hw_register(drm->dev, div);
 568
 569         priv->clk = div->clk;
 570         return ret;
 571 }
 572
 573 int pl111_display_init(struct drm_device *drm)
 574 {
 575         struct pl111_drm_dev_private *priv = drm->dev_private;
 576         int ret;
 577
 578         ret = pl111_init_clock_divider(drm);
 579         if (ret)
 580                 return ret;
 581
 582         if (!priv->variant->broken_vblank) {
 583                 pl111_display_funcs.enable_vblank = pl111_display_enable_vblank;
 584                 pl111_display_funcs.disable_vblank = pl111_display_disable_vblank;
 585         }
 586
 587         ret = drm_simple_display_pipe_init(drm, &priv->pipe,
 588                                            &pl111_display_funcs,
 589                                            priv->variant->formats,
 590                                            priv->variant->nformats,
 591                                            NULL,
 592                                            priv->connector);
 593         if (ret)
 594                 return ret;
 595
 596         return 0;
 597 }