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