drivers/gpu/drm/rcar-du/rcar_lvds.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * rcar_lvds.c  --  R-Car LVDS Encoder
   4  *
   5  * Copyright (C) 2013-2018 Renesas Electronics Corporation
   6  *
   7  * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   8  */
   9
  10 #include <linux/clk.h>
  11 #include <linux/delay.h>
  12 #include <linux/io.h>
  13 #include <linux/of.h>
  14 #include <linux/of_device.h>
  15 #include <linux/of_graph.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/slab.h>
  18
  19 #include <drm/drm_atomic.h>
  20 #include <drm/drm_atomic_helper.h>
  21 #include <drm/drm_bridge.h>
  22 #include <drm/drm_crtc_helper.h>
  23 #include <drm/drm_panel.h>
  24
  25 #include "rcar_lvds_regs.h"
  26
  27 /* Keep in sync with the LVDCR0.LVMD hardware register values. */
  28 enum rcar_lvds_mode {
  29         RCAR_LVDS_MODE_JEIDA = 0,
  30         RCAR_LVDS_MODE_MIRROR = 1,
  31         RCAR_LVDS_MODE_VESA = 4,
  32 };
  33
  34 #define RCAR_LVDS_QUIRK_LANES   (1 << 0)        /* LVDS lanes 1 and 3 inverted */
  35 #define RCAR_LVDS_QUIRK_GEN2_PLLCR (1 << 1)     /* LVDPLLCR has gen2 layout */
  36 #define RCAR_LVDS_QUIRK_GEN3_LVEN (1 << 2)      /* LVEN bit needs to be set */
  37                                                 /* on R8A77970/R8A7799x */
  38
  39 struct rcar_lvds_device_info {
  40         unsigned int gen;
  41         unsigned int quirks;
  42 };
  43
  44 struct rcar_lvds {
  45         struct device *dev;
  46         const struct rcar_lvds_device_info *info;
  47
  48         struct drm_bridge bridge;
  49
  50         struct drm_bridge *next_bridge;
  51         struct drm_connector connector;
  52         struct drm_panel *panel;
  53
  54         void __iomem *mmio;
  55         struct clk *clock;
  56         bool enabled;
  57
  58         struct drm_display_mode display_mode;
  59         enum rcar_lvds_mode mode;
  60 };
  61
  62 #define bridge_to_rcar_lvds(b) \
  63         container_of(b, struct rcar_lvds, bridge)
  64
  65 #define connector_to_rcar_lvds(c) \
  66         container_of(c, struct rcar_lvds, connector)
  67
  68 static void rcar_lvds_write(struct rcar_lvds *lvds, u32 reg, u32 data)
  69 {
  70         iowrite32(data, lvds->mmio + reg);
  71 }
  72
  73 /* -----------------------------------------------------------------------------
  74  * Connector & Panel
  75  */
  76
  77 static int rcar_lvds_connector_get_modes(struct drm_connector *connector)
  78 {
  79         struct rcar_lvds *lvds = connector_to_rcar_lvds(connector);
  80
  81         return drm_panel_get_modes(lvds->panel);
  82 }
  83
  84 static int rcar_lvds_connector_atomic_check(struct drm_connector *connector,
  85                                             struct drm_connector_state *state)
  86 {
  87         struct rcar_lvds *lvds = connector_to_rcar_lvds(connector);
  88         const struct drm_display_mode *panel_mode;
  89         struct drm_crtc_state *crtc_state;
  90
  91         if (!state->crtc)
  92                 return 0;
  93
  94         if (list_empty(&connector->modes)) {
  95                 dev_dbg(lvds->dev, "connector: empty modes list\n");
  96                 return -EINVAL;
  97         }
  98
  99         panel_mode = list_first_entry(&connector->modes,
 100                                       struct drm_display_mode, head);
 101
 102         /* We're not allowed to modify the resolution. */
 103         crtc_state = drm_atomic_get_crtc_state(state->state, state->crtc);
 104         if (IS_ERR(crtc_state))
 105                 return PTR_ERR(crtc_state);
 106
 107         if (crtc_state->mode.hdisplay != panel_mode->hdisplay ||
 108             crtc_state->mode.vdisplay != panel_mode->vdisplay)
 109                 return -EINVAL;
 110
 111         /* The flat panel mode is fixed, just copy it to the adjusted mode. */
 112         drm_mode_copy(&crtc_state->adjusted_mode, panel_mode);
 113
 114         return 0;
 115 }
 116
 117 static const struct drm_connector_helper_funcs rcar_lvds_conn_helper_funcs = {
 118         .get_modes = rcar_lvds_connector_get_modes,
 119         .atomic_check = rcar_lvds_connector_atomic_check,
 120 };
 121
 122 static const struct drm_connector_funcs rcar_lvds_conn_funcs = {
 123         .reset = drm_atomic_helper_connector_reset,
 124         .fill_modes = drm_helper_probe_single_connector_modes,
 125         .destroy = drm_connector_cleanup,
 126         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 127         .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 128 };
 129
 130 /* -----------------------------------------------------------------------------
 131  * Bridge
 132  */
 133
 134 static u32 rcar_lvds_lvdpllcr_gen2(unsigned int freq)
 135 {
 136         if (freq < 39000)
 137                 return LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_38M;
 138         else if (freq < 61000)
 139                 return LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_60M;
 140         else if (freq < 121000)
 141                 return LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_121M;
 142         else
 143                 return LVDPLLCR_PLLDLYCNT_150M;
 144 }
 145
 146 static u32 rcar_lvds_lvdpllcr_gen3(unsigned int freq)
 147 {
 148         if (freq < 42000)
 149                 return LVDPLLCR_PLLDIVCNT_42M;
 150         else if (freq < 85000)
 151                 return LVDPLLCR_PLLDIVCNT_85M;
 152         else if (freq < 128000)
 153                 return LVDPLLCR_PLLDIVCNT_128M;
 154         else
 155                 return LVDPLLCR_PLLDIVCNT_148M;
 156 }
 157
 158 static void rcar_lvds_enable(struct drm_bridge *bridge)
 159 {
 160         struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
 161         const struct drm_display_mode *mode = &lvds->display_mode;
 162         /*
 163          * FIXME: We should really retrieve the CRTC through the state, but how
 164          * do we get a state pointer?
 165          */
 166         struct drm_crtc *crtc = lvds->bridge.encoder->crtc;
 167         u32 lvdpllcr;
 168         u32 lvdhcr;
 169         u32 lvdcr0;
 170         int ret;
 171
 172         WARN_ON(lvds->enabled);
 173
 174         ret = clk_prepare_enable(lvds->clock);
 175         if (ret < 0)
 176                 return;
 177
 178         /*
 179          * Hardcode the channels and control signals routing for now.
 180          *
 181          * HSYNC -> CTRL0
 182          * VSYNC -> CTRL1
 183          * DISP  -> CTRL2
 184          * 0     -> CTRL3
 185          */
 186         rcar_lvds_write(lvds, LVDCTRCR, LVDCTRCR_CTR3SEL_ZERO |
 187                         LVDCTRCR_CTR2SEL_DISP | LVDCTRCR_CTR1SEL_VSYNC |
 188                         LVDCTRCR_CTR0SEL_HSYNC);
 189
 190         if (lvds->info->quirks & RCAR_LVDS_QUIRK_LANES)
 191                 lvdhcr = LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 3)
 192                        | LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 1);
 193         else
 194                 lvdhcr = LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 1)
 195                        | LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 3);
 196
 197         rcar_lvds_write(lvds, LVDCHCR, lvdhcr);
 198
 199         /* PLL clock configuration. */
 200         if (lvds->info->quirks & RCAR_LVDS_QUIRK_GEN2_PLLCR)
 201                 lvdpllcr = rcar_lvds_lvdpllcr_gen2(mode->clock);
 202         else
 203                 lvdpllcr = rcar_lvds_lvdpllcr_gen3(mode->clock);
 204         rcar_lvds_write(lvds, LVDPLLCR, lvdpllcr);
 205
 206         /* Set the LVDS mode and select the input. */
 207         lvdcr0 = lvds->mode << LVDCR0_LVMD_SHIFT;
 208         if (drm_crtc_index(crtc) == 2)
 209                 lvdcr0 |= LVDCR0_DUSEL;
 210         rcar_lvds_write(lvds, LVDCR0, lvdcr0);
 211
 212         /* Turn all the channels on. */
 213         rcar_lvds_write(lvds, LVDCR1,
 214                         LVDCR1_CHSTBY(3) | LVDCR1_CHSTBY(2) |
 215                         LVDCR1_CHSTBY(1) | LVDCR1_CHSTBY(0) | LVDCR1_CLKSTBY);
 216
 217         if (lvds->info->gen < 3) {
 218                 /* Enable LVDS operation and turn the bias circuitry on. */
 219                 lvdcr0 |= LVDCR0_BEN | LVDCR0_LVEN;
 220                 rcar_lvds_write(lvds, LVDCR0, lvdcr0);
 221         }
 222
 223         /* Turn the PLL on. */
 224         lvdcr0 |= LVDCR0_PLLON;
 225         rcar_lvds_write(lvds, LVDCR0, lvdcr0);
 226
 227         if (lvds->info->gen > 2) {
 228                 /* Set LVDS normal mode. */
 229                 lvdcr0 |= LVDCR0_PWD;
 230                 rcar_lvds_write(lvds, LVDCR0, lvdcr0);
 231         }
 232
 233         if (lvds->info->quirks & RCAR_LVDS_QUIRK_GEN3_LVEN) {
 234                 /* Turn on the LVDS PHY. */
 235                 lvdcr0 |= LVDCR0_LVEN;
 236                 rcar_lvds_write(lvds, LVDCR0, lvdcr0);
 237         }
 238
 239         /* Wait for the startup delay. */
 240         usleep_range(100, 150);
 241
 242         /* Turn the output on. */
 243         lvdcr0 |= LVDCR0_LVRES;
 244         rcar_lvds_write(lvds, LVDCR0, lvdcr0);
 245
 246         if (lvds->panel) {
 247                 drm_panel_prepare(lvds->panel);
 248                 drm_panel_enable(lvds->panel);
 249         }
 250
 251         lvds->enabled = true;
 252 }
 253
 254 static void rcar_lvds_disable(struct drm_bridge *bridge)
 255 {
 256         struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
 257
 258         WARN_ON(!lvds->enabled);
 259
 260         if (lvds->panel) {
 261                 drm_panel_disable(lvds->panel);
 262                 drm_panel_unprepare(lvds->panel);
 263         }
 264
 265         rcar_lvds_write(lvds, LVDCR0, 0);
 266         rcar_lvds_write(lvds, LVDCR1, 0);
 267
 268         clk_disable_unprepare(lvds->clock);
 269
 270         lvds->enabled = false;
 271 }
 272
 273 static bool rcar_lvds_mode_fixup(struct drm_bridge *bridge,
 274                                  const struct drm_display_mode *mode,
 275                                  struct drm_display_mode *adjusted_mode)
 276 {
 277         /*
 278          * The internal LVDS encoder has a restricted clock frequency operating
 279          * range (31MHz to 148.5MHz). Clamp the clock accordingly.
 280          */
 281         adjusted_mode->clock = clamp(adjusted_mode->clock, 31000, 148500);
 282
 283         return true;
 284 }
 285
 286 static void rcar_lvds_get_lvds_mode(struct rcar_lvds *lvds)
 287 {
 288         struct drm_display_info *info = &lvds->connector.display_info;
 289         enum rcar_lvds_mode mode;
 290
 291         /*
 292          * There is no API yet to retrieve LVDS mode from a bridge, only panels
 293          * are supported.
 294          */
 295         if (!lvds->panel)
 296                 return;
 297
 298         if (!info->num_bus_formats || !info->bus_formats) {
 299                 dev_err(lvds->dev, "no LVDS bus format reported\n");
 300                 return;
 301         }
 302
 303         switch (info->bus_formats[0]) {
 304         case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
 305         case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
 306                 mode = RCAR_LVDS_MODE_JEIDA;
 307                 break;
 308         case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
 309                 mode = RCAR_LVDS_MODE_VESA;
 310                 break;
 311         default:
 312                 dev_err(lvds->dev, "unsupported LVDS bus format 0x%04x\n",
 313                         info->bus_formats[0]);
 314                 return;
 315         }
 316
 317         if (info->bus_flags & DRM_BUS_FLAG_DATA_LSB_TO_MSB)
 318                 mode |= RCAR_LVDS_MODE_MIRROR;
 319
 320         lvds->mode = mode;
 321 }
 322
 323 static void rcar_lvds_mode_set(struct drm_bridge *bridge,
 324                                struct drm_display_mode *mode,
 325                                struct drm_display_mode *adjusted_mode)
 326 {
 327         struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
 328
 329         WARN_ON(lvds->enabled);
 330
 331         lvds->display_mode = *adjusted_mode;
 332
 333         rcar_lvds_get_lvds_mode(lvds);
 334 }
 335
 336 static int rcar_lvds_attach(struct drm_bridge *bridge)
 337 {
 338         struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
 339         struct drm_connector *connector = &lvds->connector;
 340         struct drm_encoder *encoder = bridge->encoder;
 341         int ret;
 342
 343         /* If we have a next bridge just attach it. */
 344         if (lvds->next_bridge)
 345                 return drm_bridge_attach(bridge->encoder, lvds->next_bridge,
 346                                          bridge);
 347
 348         /* Otherwise we have a panel, create a connector. */
 349         ret = drm_connector_init(bridge->dev, connector, &rcar_lvds_conn_funcs,
 350                                  DRM_MODE_CONNECTOR_LVDS);
 351         if (ret < 0)
 352                 return ret;
 353
 354         drm_connector_helper_add(connector, &rcar_lvds_conn_helper_funcs);
 355
 356         ret = drm_connector_attach_encoder(connector, encoder);
 357         if (ret < 0)
 358                 return ret;
 359
 360         return drm_panel_attach(lvds->panel, connector);
 361 }
 362
 363 static void rcar_lvds_detach(struct drm_bridge *bridge)
 364 {
 365         struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
 366
 367         if (lvds->panel)
 368                 drm_panel_detach(lvds->panel);
 369 }
 370
 371 static const struct drm_bridge_funcs rcar_lvds_bridge_ops = {
 372         .attach = rcar_lvds_attach,
 373         .detach = rcar_lvds_detach,
 374         .enable = rcar_lvds_enable,
 375         .disable = rcar_lvds_disable,
 376         .mode_fixup = rcar_lvds_mode_fixup,
 377         .mode_set = rcar_lvds_mode_set,
 378 };
 379
 380 /* -----------------------------------------------------------------------------
 381  * Probe & Remove
 382  */
 383
 384 static int rcar_lvds_parse_dt(struct rcar_lvds *lvds)
 385 {
 386         struct device_node *local_output = NULL;
 387         struct device_node *remote_input = NULL;
 388         struct device_node *remote = NULL;
 389         struct device_node *node;
 390         bool is_bridge = false;
 391         int ret = 0;
 392
 393         local_output = of_graph_get_endpoint_by_regs(lvds->dev->of_node, 1, 0);
 394         if (!local_output) {
 395                 dev_dbg(lvds->dev, "unconnected port@1\n");
 396                 return -ENODEV;
 397         }
 398
 399         /*
 400          * Locate the connected entity and infer its type from the number of
 401          * endpoints.
 402          */
 403         remote = of_graph_get_remote_port_parent(local_output);
 404         if (!remote) {
 405                 dev_dbg(lvds->dev, "unconnected endpoint %pOF\n", local_output);
 406                 ret = -ENODEV;
 407                 goto done;
 408         }
 409
 410         if (!of_device_is_available(remote)) {
 411                 dev_dbg(lvds->dev, "connected entity %pOF is disabled\n",
 412                         remote);
 413                 ret = -ENODEV;
 414                 goto done;
 415         }
 416
 417         remote_input = of_graph_get_remote_endpoint(local_output);
 418
 419         for_each_endpoint_of_node(remote, node) {
 420                 if (node != remote_input) {
 421                         /*
 422                          * We've found one endpoint other than the input, this
 423                          * must be a bridge.
 424                          */
 425                         is_bridge = true;
 426                         of_node_put(node);
 427                         break;
 428                 }
 429         }
 430
 431         if (is_bridge) {
 432                 lvds->next_bridge = of_drm_find_bridge(remote);
 433                 if (!lvds->next_bridge)
 434                         ret = -EPROBE_DEFER;
 435         } else {
 436                 lvds->panel = of_drm_find_panel(remote);
 437                 if (IS_ERR(lvds->panel))
 438                         ret = PTR_ERR(lvds->panel);
 439         }
 440
 441 done:
 442         of_node_put(local_output);
 443         of_node_put(remote_input);
 444         of_node_put(remote);
 445
 446         return ret;
 447 }
 448
 449 static int rcar_lvds_probe(struct platform_device *pdev)
 450 {
 451         struct rcar_lvds *lvds;
 452         struct resource *mem;
 453         int ret;
 454
 455         lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
 456         if (lvds == NULL)
 457                 return -ENOMEM;
 458
 459         platform_set_drvdata(pdev, lvds);
 460
 461         lvds->dev = &pdev->dev;
 462         lvds->info = of_device_get_match_data(&pdev->dev);
 463         lvds->enabled = false;
 464
 465         ret = rcar_lvds_parse_dt(lvds);
 466         if (ret < 0)
 467                 return ret;
 468
 469         lvds->bridge.driver_private = lvds;
 470         lvds->bridge.funcs = &rcar_lvds_bridge_ops;
 471         lvds->bridge.of_node = pdev->dev.of_node;
 472
 473         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 474         lvds->mmio = devm_ioremap_resource(&pdev->dev, mem);
 475         if (IS_ERR(lvds->mmio))
 476                 return PTR_ERR(lvds->mmio);
 477
 478         lvds->clock = devm_clk_get(&pdev->dev, NULL);
 479         if (IS_ERR(lvds->clock)) {
 480                 dev_err(&pdev->dev, "failed to get clock\n");
 481                 return PTR_ERR(lvds->clock);
 482         }
 483
 484         drm_bridge_add(&lvds->bridge);
 485
 486         return 0;
 487 }
 488
 489 static int rcar_lvds_remove(struct platform_device *pdev)
 490 {
 491         struct rcar_lvds *lvds = platform_get_drvdata(pdev);
 492
 493         drm_bridge_remove(&lvds->bridge);
 494
 495         return 0;
 496 }
 497
 498 static const struct rcar_lvds_device_info rcar_lvds_gen2_info = {
 499         .gen = 2,
 500         .quirks = RCAR_LVDS_QUIRK_GEN2_PLLCR,
 501 };
 502
 503 static const struct rcar_lvds_device_info rcar_lvds_r8a7790_info = {
 504         .gen = 2,
 505         .quirks = RCAR_LVDS_QUIRK_GEN2_PLLCR | RCAR_LVDS_QUIRK_LANES,
 506 };
 507
 508 static const struct rcar_lvds_device_info rcar_lvds_gen3_info = {
 509         .gen = 3,
 510 };
 511
 512 static const struct rcar_lvds_device_info rcar_lvds_r8a77970_info = {
 513         .gen = 3,
 514         .quirks = RCAR_LVDS_QUIRK_GEN2_PLLCR | RCAR_LVDS_QUIRK_GEN3_LVEN,
 515 };
 516
 517 static const struct of_device_id rcar_lvds_of_table[] = {
 518         { .compatible = "renesas,r8a7743-lvds", .data = &rcar_lvds_gen2_info },
 519         { .compatible = "renesas,r8a7790-lvds", .data = &rcar_lvds_r8a7790_info },
 520         { .compatible = "renesas,r8a7791-lvds", .data = &rcar_lvds_gen2_info },
 521         { .compatible = "renesas,r8a7793-lvds", .data = &rcar_lvds_gen2_info },
 522         { .compatible = "renesas,r8a7795-lvds", .data = &rcar_lvds_gen3_info },
 523         { .compatible = "renesas,r8a7796-lvds", .data = &rcar_lvds_gen3_info },
 524         { .compatible = "renesas,r8a77970-lvds", .data = &rcar_lvds_r8a77970_info },
 525         { }
 526 };
 527
 528 MODULE_DEVICE_TABLE(of, rcar_lvds_of_table);
 529
 530 static struct platform_driver rcar_lvds_platform_driver = {
 531         .probe          = rcar_lvds_probe,
 532         .remove         = rcar_lvds_remove,
 533         .driver         = {
 534                 .name   = "rcar-lvds",
 535                 .of_match_table = rcar_lvds_of_table,
 536         },
 537 };
 538
 539 module_platform_driver(rcar_lvds_platform_driver);
 540
 541 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 542 MODULE_DESCRIPTION("Renesas R-Car LVDS Encoder Driver");
 543 MODULE_LICENSE("GPL");