drivers/gpu/drm/bridge/lontium-lt8912b.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
   4  */
   5
   6 #include <linux/device.h>
   7 #include <linux/delay.h>
   8 #include <linux/gpio/consumer.h>
   9 #include <linux/i2c.h>
  10 #include <linux/gpio.h>
  11 #include <linux/of_gpio.h>
  12 #include <linux/regmap.h>
  13
  14 #include <drm/drm_probe_helper.h>
  15 #include <drm/drm_atomic_helper.h>
  16 #include <drm/drm_mipi_dsi.h>
  17 #include <drm/drm_of.h>
  18
  19 #include <video/videomode.h>
  20
  21 #define I2C_MAIN 0
  22 #define I2C_ADDR_MAIN 0x48
  23
  24 #define I2C_CEC_DSI 1
  25 #define I2C_ADDR_CEC_DSI 0x49
  26
  27 #define I2C_MAX_IDX 2
  28
  29 struct lt8912 {
  30         struct device *dev;
  31         struct drm_bridge bridge;
  32         struct drm_connector connector;
  33
  34         struct i2c_client *i2c_client[I2C_MAX_IDX];
  35         struct regmap *regmap[I2C_MAX_IDX];
  36
  37         struct device_node *host_node;
  38         struct drm_bridge *hdmi_port;
  39
  40         struct mipi_dsi_device *dsi;
  41
  42         struct gpio_desc *gp_reset;
  43
  44         struct videomode mode;
  45
  46         u8 data_lanes;
  47         bool is_power_on;
  48         bool is_attached;
  49 };
  50
  51 static int lt8912_write_init_config(struct lt8912 *lt)
  52 {
  53         const struct reg_sequence seq[] = {
  54                 /* Digital clock en*/
  55                 {0x08, 0xff},
  56                 {0x09, 0xff},
  57                 {0x0a, 0xff},
  58                 {0x0b, 0x7c},
  59                 {0x0c, 0xff},
  60                 {0x42, 0x04},
  61
  62                 /*Tx Analog*/
  63                 {0x31, 0xb1},
  64                 {0x32, 0xb1},
  65                 {0x33, 0x0e},
  66                 {0x37, 0x00},
  67                 {0x38, 0x22},
  68                 {0x60, 0x82},
  69
  70                 /*Cbus Analog*/
  71                 {0x39, 0x45},
  72                 {0x3a, 0x00},
  73                 {0x3b, 0x00},
  74
  75                 /*HDMI Pll Analog*/
  76                 {0x44, 0x31},
  77                 {0x55, 0x44},
  78                 {0x57, 0x01},
  79                 {0x5a, 0x02},
  80
  81                 /*MIPI Analog*/
  82                 {0x3e, 0xd6},
  83                 {0x3f, 0xd4},
  84                 {0x41, 0x3c},
  85                 {0xB2, 0x00},
  86         };
  87
  88         return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SIZE(seq));
  89 }
  90
  91 static int lt8912_write_mipi_basic_config(struct lt8912 *lt)
  92 {
  93         const struct reg_sequence seq[] = {
  94                 {0x12, 0x04},
  95                 {0x14, 0x00},
  96                 {0x15, 0x00},
  97                 {0x1a, 0x03},
  98                 {0x1b, 0x03},
  99         };
 100
 101         return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq));
 102 };
 103
 104 static int lt8912_write_dds_config(struct lt8912 *lt)
 105 {
 106         const struct reg_sequence seq[] = {
 107                 {0x4e, 0xff},
 108                 {0x4f, 0x56},
 109                 {0x50, 0x69},
 110                 {0x51, 0x80},
 111                 {0x1f, 0x5e},
 112                 {0x20, 0x01},
 113                 {0x21, 0x2c},
 114                 {0x22, 0x01},
 115                 {0x23, 0xfa},
 116                 {0x24, 0x00},
 117                 {0x25, 0xc8},
 118                 {0x26, 0x00},
 119                 {0x27, 0x5e},
 120                 {0x28, 0x01},
 121                 {0x29, 0x2c},
 122                 {0x2a, 0x01},
 123                 {0x2b, 0xfa},
 124                 {0x2c, 0x00},
 125                 {0x2d, 0xc8},
 126                 {0x2e, 0x00},
 127                 {0x42, 0x64},
 128                 {0x43, 0x00},
 129                 {0x44, 0x04},
 130                 {0x45, 0x00},
 131                 {0x46, 0x59},
 132                 {0x47, 0x00},
 133                 {0x48, 0xf2},
 134                 {0x49, 0x06},
 135                 {0x4a, 0x00},
 136                 {0x4b, 0x72},
 137                 {0x4c, 0x45},
 138                 {0x4d, 0x00},
 139                 {0x52, 0x08},
 140                 {0x53, 0x00},
 141                 {0x54, 0xb2},
 142                 {0x55, 0x00},
 143                 {0x56, 0xe4},
 144                 {0x57, 0x0d},
 145                 {0x58, 0x00},
 146                 {0x59, 0xe4},
 147                 {0x5a, 0x8a},
 148                 {0x5b, 0x00},
 149                 {0x5c, 0x34},
 150                 {0x1e, 0x4f},
 151                 {0x51, 0x00},
 152         };
 153
 154         return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq));
 155 }
 156
 157 static int lt8912_write_rxlogicres_config(struct lt8912 *lt)
 158 {
 159         int ret;
 160
 161         ret = regmap_write(lt->regmap[I2C_MAIN], 0x03, 0x7f);
 162         usleep_range(10000, 20000);
 163         ret |= regmap_write(lt->regmap[I2C_MAIN], 0x03, 0xff);
 164
 165         return ret;
 166 };
 167
 168 static int lt8912_write_lvds_config(struct lt8912 *lt)
 169 {
 170         const struct reg_sequence seq[] = {
 171                 {0x44, 0x30},
 172                 {0x51, 0x05},
 173                 {0x50, 0x24},
 174                 {0x51, 0x2d},
 175                 {0x52, 0x04},
 176                 {0x69, 0x0e},
 177                 {0x69, 0x8e},
 178                 {0x6a, 0x00},
 179                 {0x6c, 0xb8},
 180                 {0x6b, 0x51},
 181                 {0x04, 0xfb},
 182                 {0x04, 0xff},
 183                 {0x7f, 0x00},
 184                 {0xa8, 0x13},
 185                 {0x02, 0xf7},
 186                 {0x02, 0xff},
 187                 {0x03, 0xcf},
 188                 {0x03, 0xff},
 189         };
 190
 191         return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq));
 192 };
 193
 194 static inline struct lt8912 *bridge_to_lt8912(struct drm_bridge *b)
 195 {
 196         return container_of(b, struct lt8912, bridge);
 197 }
 198
 199 static inline struct lt8912 *connector_to_lt8912(struct drm_connector *c)
 200 {
 201         return container_of(c, struct lt8912, connector);
 202 }
 203
 204 static const struct regmap_config lt8912_regmap_config = {
 205         .reg_bits = 8,
 206         .val_bits = 8,
 207         .max_register = 0xff,
 208 };
 209
 210 static int lt8912_init_i2c(struct lt8912 *lt, struct i2c_client *client)
 211 {
 212         unsigned int i;
 213         /*
 214          * At this time we only initialize 2 chips, but the lt8912 provides
 215          * a third interface for the audio over HDMI configuration.
 216          */
 217         struct i2c_board_info info[] = {
 218                 { I2C_BOARD_INFO("lt8912p0", I2C_ADDR_MAIN), },
 219                 { I2C_BOARD_INFO("lt8912p1", I2C_ADDR_CEC_DSI), },
 220         };
 221
 222         if (!lt)
 223                 return -ENODEV;
 224
 225         for (i = 0; i < ARRAY_SIZE(info); i++) {
 226                 if (i > 0) {
 227                         lt->i2c_client[i] = i2c_new_dummy_device(client->adapter,
 228                                                                  info[i].addr);
 229                         if (IS_ERR(lt->i2c_client[i]))
 230                                 return PTR_ERR(lt->i2c_client[i]);
 231                 }
 232
 233                 lt->regmap[i] = devm_regmap_init_i2c(lt->i2c_client[i],
 234                                                      &lt8912_regmap_config);
 235                 if (IS_ERR(lt->regmap[i]))
 236                         return PTR_ERR(lt->regmap[i]);
 237         }
 238         return 0;
 239 }
 240
 241 static int lt8912_free_i2c(struct lt8912 *lt)
 242 {
 243         unsigned int i;
 244
 245         for (i = 1; i < I2C_MAX_IDX; i++)
 246                 i2c_unregister_device(lt->i2c_client[i]);
 247
 248         return 0;
 249 }
 250
 251 static int lt8912_hard_power_on(struct lt8912 *lt)
 252 {
 253         gpiod_set_value_cansleep(lt->gp_reset, 0);
 254         msleep(20);
 255
 256         return 0;
 257 }
 258
 259 static void lt8912_hard_power_off(struct lt8912 *lt)
 260 {
 261         gpiod_set_value_cansleep(lt->gp_reset, 1);
 262         msleep(20);
 263         lt->is_power_on = false;
 264 }
 265
 266 static int lt8912_video_setup(struct lt8912 *lt)
 267 {
 268         u32 hactive, h_total, hpw, hfp, hbp;
 269         u32 vactive, v_total, vpw, vfp, vbp;
 270         u8 settle = 0x08;
 271         int ret;
 272
 273         if (!lt)
 274                 return -EINVAL;
 275
 276         hactive = lt->mode.hactive;
 277         hfp = lt->mode.hfront_porch;
 278         hpw = lt->mode.hsync_len;
 279         hbp = lt->mode.hback_porch;
 280         h_total = hactive + hfp + hpw + hbp;
 281
 282         vactive = lt->mode.vactive;
 283         vfp = lt->mode.vfront_porch;
 284         vpw = lt->mode.vsync_len;
 285         vbp = lt->mode.vback_porch;
 286         v_total = vactive + vfp + vpw + vbp;
 287
 288         if (vactive <= 600)
 289                 settle = 0x04;
 290         else if (vactive == 1080)
 291                 settle = 0x0a;
 292
 293         ret = regmap_write(lt->regmap[I2C_CEC_DSI], 0x10, 0x01);
 294         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x11, settle);
 295         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x18, hpw);
 296         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x19, vpw);
 297         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x1c, hactive & 0xff);
 298         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x1d, hactive >> 8);
 299
 300         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x2f, 0x0c);
 301
 302         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x34, h_total & 0xff);
 303         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x35, h_total >> 8);
 304
 305         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x36, v_total & 0xff);
 306         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x37, v_total >> 8);
 307
 308         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x38, vbp & 0xff);
 309         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x39, vbp >> 8);
 310
 311         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3a, vfp & 0xff);
 312         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3b, vfp >> 8);
 313
 314         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3c, hbp & 0xff);
 315         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3d, hbp >> 8);
 316
 317         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3e, hfp & 0xff);
 318         ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3f, hfp >> 8);
 319
 320         return ret;
 321 }
 322
 323 static int lt8912_soft_power_on(struct lt8912 *lt)
 324 {
 325         if (!lt->is_power_on) {
 326                 u32 lanes = lt->data_lanes;
 327
 328                 lt8912_write_init_config(lt);
 329                 regmap_write(lt->regmap[I2C_CEC_DSI], 0x13, lanes & 3);
 330
 331                 lt8912_write_mipi_basic_config(lt);
 332
 333                 lt->is_power_on = true;
 334         }
 335
 336         return 0;
 337 }
 338
 339 static int lt8912_video_on(struct lt8912 *lt)
 340 {
 341         int ret;
 342
 343         ret = lt8912_video_setup(lt);
 344         if (ret < 0)
 345                 goto end;
 346
 347         ret = lt8912_write_dds_config(lt);
 348         if (ret < 0)
 349                 goto end;
 350
 351         ret = lt8912_write_rxlogicres_config(lt);
 352         if (ret < 0)
 353                 goto end;
 354
 355         ret = lt8912_write_lvds_config(lt);
 356         if (ret < 0)
 357                 goto end;
 358
 359 end:
 360         return ret;
 361 }
 362
 363 static enum drm_connector_status lt8912_check_cable_status(struct lt8912 *lt)
 364 {
 365         int ret;
 366         unsigned int reg_val;
 367
 368         ret = regmap_read(lt->regmap[I2C_MAIN], 0xC1, &reg_val);
 369         if (ret)
 370                 return connector_status_unknown;
 371
 372         if (reg_val & BIT(7))
 373                 return connector_status_connected;
 374
 375         return connector_status_disconnected;
 376 }
 377
 378 static enum drm_connector_status
 379 lt8912_connector_detect(struct drm_connector *connector, bool force)
 380 {
 381         struct lt8912 *lt = connector_to_lt8912(connector);
 382
 383         if (lt->hdmi_port->ops & DRM_BRIDGE_OP_DETECT)
 384                 return drm_bridge_detect(lt->hdmi_port);
 385
 386         return lt8912_check_cable_status(lt);
 387 }
 388
 389 static const struct drm_connector_funcs lt8912_connector_funcs = {
 390         .detect = lt8912_connector_detect,
 391         .fill_modes = drm_helper_probe_single_connector_modes,
 392         .destroy = drm_connector_cleanup,
 393         .reset = drm_atomic_helper_connector_reset,
 394         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 395         .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 396 };
 397
 398 static enum drm_mode_status
 399 lt8912_connector_mode_valid(struct drm_connector *connector,
 400                             struct drm_display_mode *mode)
 401 {
 402         if (mode->clock > 150000)
 403                 return MODE_CLOCK_HIGH;
 404
 405         if (mode->hdisplay > 1920)
 406                 return MODE_BAD_HVALUE;
 407
 408         if (mode->vdisplay > 1080)
 409                 return MODE_BAD_VVALUE;
 410
 411         return MODE_OK;
 412 }
 413
 414 static int lt8912_connector_get_modes(struct drm_connector *connector)
 415 {
 416         struct edid *edid;
 417         int ret = -1;
 418         int num = 0;
 419         struct lt8912 *lt = connector_to_lt8912(connector);
 420         u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 421
 422         edid = drm_bridge_get_edid(lt->hdmi_port, connector);
 423         if (edid) {
 424                 drm_connector_update_edid_property(connector, edid);
 425                 num = drm_add_edid_modes(connector, edid);
 426         } else {
 427                 return ret;
 428         }
 429
 430         ret = drm_display_info_set_bus_formats(&connector->display_info,
 431                                                &bus_format, 1);
 432         if (ret)
 433                 num = ret;
 434
 435         kfree(edid);
 436         return num;
 437 }
 438
 439 static const struct drm_connector_helper_funcs lt8912_connector_helper_funcs = {
 440         .get_modes = lt8912_connector_get_modes,
 441         .mode_valid = lt8912_connector_mode_valid,
 442 };
 443
 444 static void lt8912_bridge_mode_set(struct drm_bridge *bridge,
 445                                    const struct drm_display_mode *mode,
 446                                    const struct drm_display_mode *adj)
 447 {
 448         struct lt8912 *lt = bridge_to_lt8912(bridge);
 449
 450         drm_display_mode_to_videomode(adj, &lt->mode);
 451 }
 452
 453 static void lt8912_bridge_enable(struct drm_bridge *bridge)
 454 {
 455         struct lt8912 *lt = bridge_to_lt8912(bridge);
 456
 457         lt8912_video_on(lt);
 458 }
 459
 460 static int lt8912_attach_dsi(struct lt8912 *lt)
 461 {
 462         struct device *dev = lt->dev;
 463         struct mipi_dsi_host *host;
 464         struct mipi_dsi_device *dsi;
 465         int ret = -1;
 466         const struct mipi_dsi_device_info info = { .type = "lt8912",
 467                                                    .channel = 0,
 468                                                    .node = NULL,
 469                                                  };
 470
 471         host = of_find_mipi_dsi_host_by_node(lt->host_node);
 472         if (!host) {
 473                 dev_err(dev, "failed to find dsi host\n");
 474                 return -EPROBE_DEFER;
 475         }
 476
 477         dsi = mipi_dsi_device_register_full(host, &info);
 478         if (IS_ERR(dsi)) {
 479                 ret = PTR_ERR(dsi);
 480                 dev_err(dev, "failed to create dsi device (%d)\n", ret);
 481                 goto err_dsi_device;
 482         }
 483
 484         lt->dsi = dsi;
 485
 486         dsi->lanes = lt->data_lanes;
 487         dsi->format = MIPI_DSI_FMT_RGB888;
 488
 489         dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
 490                           MIPI_DSI_MODE_VIDEO_BURST |
 491                           MIPI_DSI_MODE_LPM |
 492                           MIPI_DSI_MODE_EOT_PACKET;
 493
 494         ret = mipi_dsi_attach(dsi);
 495         if (ret < 0) {
 496                 dev_err(dev, "failed to attach dsi to host\n");
 497                 goto err_dsi_attach;
 498         }
 499
 500         return 0;
 501
 502 err_dsi_attach:
 503         mipi_dsi_device_unregister(dsi);
 504 err_dsi_device:
 505         return ret;
 506 }
 507
 508 static void lt8912_detach_dsi(struct lt8912 *lt)
 509 {
 510         mipi_dsi_detach(lt->dsi);
 511         mipi_dsi_device_unregister(lt->dsi);
 512 }
 513
 514 static int lt8912_bridge_connector_init(struct drm_bridge *bridge)
 515 {
 516         int ret;
 517         struct lt8912 *lt = bridge_to_lt8912(bridge);
 518         struct drm_connector *connector = &lt->connector;
 519
 520         connector->polled = DRM_CONNECTOR_POLL_CONNECT |
 521                             DRM_CONNECTOR_POLL_DISCONNECT;
 522
 523         ret = drm_connector_init(bridge->dev, connector,
 524                                  &lt8912_connector_funcs,
 525                                  lt->hdmi_port->type);
 526         if (ret)
 527                 goto exit;
 528
 529         drm_connector_helper_add(connector, &lt8912_connector_helper_funcs);
 530
 531         connector->dpms = DRM_MODE_DPMS_OFF;
 532         drm_connector_attach_encoder(connector, bridge->encoder);
 533
 534 exit:
 535         return ret;
 536 }
 537
 538 static int lt8912_bridge_attach(struct drm_bridge *bridge,
 539                                 enum drm_bridge_attach_flags flags)
 540 {
 541         struct lt8912 *lt = bridge_to_lt8912(bridge);
 542         int ret;
 543
 544         if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
 545                 ret = lt8912_bridge_connector_init(bridge);
 546                 if (ret) {
 547                         dev_err(lt->dev, "Failed to init bridge ! (%d)\n", ret);
 548                         return ret;
 549                 }
 550         }
 551
 552         ret = lt8912_hard_power_on(lt);
 553         if (ret)
 554                 return ret;
 555
 556         ret = lt8912_soft_power_on(lt);
 557         if (ret)
 558                 goto error;
 559
 560         ret = lt8912_attach_dsi(lt);
 561         if (ret)
 562                 goto error;
 563
 564         lt->is_attached = true;
 565
 566         return 0;
 567
 568 error:
 569         lt8912_hard_power_off(lt);
 570         return ret;
 571 }
 572
 573 static void lt8912_bridge_detach(struct drm_bridge *bridge)
 574 {
 575         struct lt8912 *lt = bridge_to_lt8912(bridge);
 576
 577         if (lt->is_attached) {
 578                 lt8912_detach_dsi(lt);
 579                 lt8912_hard_power_off(lt);
 580                 drm_connector_unregister(&lt->connector);
 581                 drm_connector_cleanup(&lt->connector);
 582         }
 583 }
 584
 585 static enum drm_connector_status
 586 lt8912_bridge_detect(struct drm_bridge *bridge)
 587 {
 588         struct lt8912 *lt = bridge_to_lt8912(bridge);
 589
 590         if (lt->hdmi_port->ops & DRM_BRIDGE_OP_DETECT)
 591                 return drm_bridge_detect(lt->hdmi_port);
 592
 593         return lt8912_check_cable_status(lt);
 594 }
 595
 596 static struct edid *lt8912_bridge_get_edid(struct drm_bridge *bridge,
 597                                            struct drm_connector *connector)
 598 {
 599         struct lt8912 *lt = bridge_to_lt8912(bridge);
 600
 601         /*
 602          * edid must be read through the ddc bus but it must be
 603          * given to the hdmi connector node.
 604          */
 605         if (lt->hdmi_port->ops & DRM_BRIDGE_OP_EDID)
 606                 return drm_bridge_get_edid(lt->hdmi_port, connector);
 607
 608         dev_warn(lt->dev, "The connected bridge does not supports DRM_BRIDGE_OP_EDID\n");
 609         return NULL;
 610 }
 611
 612 static const struct drm_bridge_funcs lt8912_bridge_funcs = {
 613         .attach = lt8912_bridge_attach,
 614         .detach = lt8912_bridge_detach,
 615         .mode_set = lt8912_bridge_mode_set,
 616         .enable = lt8912_bridge_enable,
 617         .detect = lt8912_bridge_detect,
 618         .get_edid = lt8912_bridge_get_edid,
 619 };
 620
 621 static int lt8912_parse_dt(struct lt8912 *lt)
 622 {
 623         struct gpio_desc *gp_reset;
 624         struct device *dev = lt->dev;
 625         int ret;
 626         int data_lanes;
 627         struct device_node *port_node;
 628         struct device_node *endpoint;
 629
 630         gp_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 631         if (IS_ERR(gp_reset)) {
 632                 ret = PTR_ERR(gp_reset);
 633                 if (ret != -EPROBE_DEFER)
 634                         dev_err(dev, "Failed to get reset gpio: %d\n", ret);
 635                 return ret;
 636         }
 637         lt->gp_reset = gp_reset;
 638
 639         endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
 640         if (!endpoint)
 641                 return -ENODEV;
 642
 643         data_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
 644         of_node_put(endpoint);
 645         if (data_lanes < 0) {
 646                 dev_err(lt->dev, "%s: Bad data-lanes property\n", __func__);
 647                 return data_lanes;
 648         }
 649         lt->data_lanes = data_lanes;
 650
 651         lt->host_node = of_graph_get_remote_node(dev->of_node, 0, -1);
 652         if (!lt->host_node) {
 653                 dev_err(lt->dev, "%s: Failed to get remote port\n", __func__);
 654                 return -ENODEV;
 655         }
 656
 657         port_node = of_graph_get_remote_node(dev->of_node, 1, -1);
 658         if (!port_node) {
 659                 dev_err(lt->dev, "%s: Failed to get connector port\n", __func__);
 660                 ret = -ENODEV;
 661                 goto err_free_host_node;
 662         }
 663
 664         lt->hdmi_port = of_drm_find_bridge(port_node);
 665         if (!lt->hdmi_port) {
 666                 dev_err(lt->dev, "%s: Failed to get hdmi port\n", __func__);
 667                 ret = -ENODEV;
 668                 goto err_free_host_node;
 669         }
 670
 671         if (!of_device_is_compatible(port_node, "hdmi-connector")) {
 672                 dev_err(lt->dev, "%s: Failed to get hdmi port\n", __func__);
 673                 ret = -EINVAL;
 674                 goto err_free_host_node;
 675         }
 676
 677         of_node_put(port_node);
 678         return 0;
 679
 680 err_free_host_node:
 681         of_node_put(port_node);
 682         of_node_put(lt->host_node);
 683         return ret;
 684 }
 685
 686 static int lt8912_put_dt(struct lt8912 *lt)
 687 {
 688         of_node_put(lt->host_node);
 689         return 0;
 690 }
 691
 692 static int lt8912_probe(struct i2c_client *client,
 693                         const struct i2c_device_id *id)
 694 {
 695         static struct lt8912 *lt;
 696         int ret = 0;
 697         struct device *dev = &client->dev;
 698
 699         lt = devm_kzalloc(dev, sizeof(struct lt8912), GFP_KERNEL);
 700         if (!lt)
 701                 return -ENOMEM;
 702
 703         lt->dev = dev;
 704         lt->i2c_client[0] = client;
 705
 706         ret = lt8912_parse_dt(lt);
 707         if (ret)
 708                 goto err_dt_parse;
 709
 710         ret = lt8912_init_i2c(lt, client);
 711         if (ret)
 712                 goto err_i2c;
 713
 714         i2c_set_clientdata(client, lt);
 715
 716         lt->bridge.funcs = &lt8912_bridge_funcs;
 717         lt->bridge.of_node = dev->of_node;
 718         lt->bridge.ops = (DRM_BRIDGE_OP_EDID |
 719                           DRM_BRIDGE_OP_DETECT);
 720
 721         drm_bridge_add(&lt->bridge);
 722
 723         return 0;
 724
 725 err_i2c:
 726         lt8912_put_dt(lt);
 727 err_dt_parse:
 728         return ret;
 729 }
 730
 731 static int lt8912_remove(struct i2c_client *client)
 732 {
 733         struct lt8912 *lt = i2c_get_clientdata(client);
 734
 735         lt8912_bridge_detach(&lt->bridge);
 736         drm_bridge_remove(&lt->bridge);
 737         lt8912_free_i2c(lt);
 738         lt8912_put_dt(lt);
 739         return 0;
 740 }
 741
 742 static const struct of_device_id lt8912_dt_match[] = {
 743         {.compatible = "lontium,lt8912b"},
 744         {}
 745 };
 746 MODULE_DEVICE_TABLE(of, lt8912_dt_match);
 747
 748 static const struct i2c_device_id lt8912_id[] = {
 749         {"lt8912", 0},
 750         {},
 751 };
 752 MODULE_DEVICE_TABLE(i2c, lt8912_id);
 753
 754 static struct i2c_driver lt8912_i2c_driver = {
 755         .driver = {
 756                 .name = "lt8912",
 757                 .of_match_table = lt8912_dt_match,
 758                 .owner = THIS_MODULE,
 759         },
 760         .probe = lt8912_probe,
 761         .remove = lt8912_remove,
 762         .id_table = lt8912_id,
 763 };
 764 module_i2c_driver(lt8912_i2c_driver);
 765
 766 MODULE_AUTHOR("Adrien Grassein <adrien.grassein@gmail.com>");
 767 MODULE_DESCRIPTION("lt8912 drm driver");
 768 MODULE_LICENSE("GPL v2");