1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Parade PS8622 eDP/LVDS bridge driver 4 * 5 * Copyright (C) 2014 Google, Inc. 6 */ 7 8 #include <linux/backlight.h> 9 #include <linux/delay.h> 10 #include <linux/err.h> 11 #include <linux/gpio/consumer.h> 12 #include <linux/i2c.h> 13 #include <linux/module.h> 14 #include <linux/of.h> 15 #include <linux/of_device.h> 16 #include <linux/pm.h> 17 #include <linux/regulator/consumer.h> 18 19 #include <drm/drm_atomic_helper.h> 20 #include <drm/drm_bridge.h> 21 #include <drm/drm_crtc.h> 22 #include <drm/drm_of.h> 23 #include <drm/drm_panel.h> 24 #include <drm/drm_print.h> 25 #include <drm/drm_probe_helper.h> 26 27 /* Brightness scale on the Parade chip */ 28 #define PS8622_MAX_BRIGHTNESS 0xff 29 30 /* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */ 31 #define PS8622_POWER_RISE_T1_MIN_US 10 32 #define PS8622_POWER_RISE_T1_MAX_US 10000 33 #define PS8622_RST_HIGH_T2_MIN_US 3000 34 #define PS8622_RST_HIGH_T2_MAX_US 30000 35 #define PS8622_PWMO_END_T12_MS 200 36 #define PS8622_POWER_FALL_T16_MAX_US 10000 37 #define PS8622_POWER_OFF_T17_MS 500 38 39 #if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \ 40 (PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US)) 41 #error "T2.min + T1.max must be less than T2.max + T1.min" 42 #endif 43 44 struct ps8622_bridge { 45 struct drm_connector connector; 46 struct i2c_client *client; 47 struct drm_bridge bridge; 48 struct drm_panel *panel; 49 struct regulator *v12; 50 struct backlight_device *bl; 51 52 struct gpio_desc *gpio_slp; 53 struct gpio_desc *gpio_rst; 54 55 u32 max_lane_count; 56 u32 lane_count; 57 58 bool enabled; 59 }; 60 61 static inline struct ps8622_bridge * 62 bridge_to_ps8622(struct drm_bridge *bridge) 63 { 64 return container_of(bridge, struct ps8622_bridge, bridge); 65 } 66 67 static inline struct ps8622_bridge * 68 connector_to_ps8622(struct drm_connector *connector) 69 { 70 return container_of(connector, struct ps8622_bridge, connector); 71 } 72 73 static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val) 74 { 75 int ret; 76 struct i2c_adapter *adap = client->adapter; 77 struct i2c_msg msg; 78 u8 data[] = {reg, val}; 79 80 msg.addr = client->addr + page; 81 msg.flags = 0; 82 msg.len = sizeof(data); 83 msg.buf = data; 84 85 ret = i2c_transfer(adap, &msg, 1); 86 if (ret != 1) 87 pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n", 88 client->addr + page, reg, val, ret); 89 return !(ret == 1); 90 } 91 92 static int ps8622_send_config(struct ps8622_bridge *ps8622) 93 { 94 struct i2c_client *cl = ps8622->client; 95 int err = 0; 96 97 /* HPD low */ 98 err = ps8622_set(cl, 0x02, 0xa1, 0x01); 99 if (err) 100 goto error; 101 102 /* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */ 103 err = ps8622_set(cl, 0x04, 0x14, 0x01); 104 if (err) 105 goto error; 106 107 /* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */ 108 err = ps8622_set(cl, 0x04, 0xe3, 0x20); 109 if (err) 110 goto error; 111 112 /* [7] RCO SS enable */ 113 err = ps8622_set(cl, 0x04, 0xe2, 0x80); 114 if (err) 115 goto error; 116 117 /* RPHY Setting 118 * [3:2] CDR tune wait cycle before measure for fine tune 119 * b00: 1us b01: 0.5us b10:2us, b11: 4us 120 */ 121 err = ps8622_set(cl, 0x04, 0x8a, 0x0c); 122 if (err) 123 goto error; 124 125 /* [3] RFD always on */ 126 err = ps8622_set(cl, 0x04, 0x89, 0x08); 127 if (err) 128 goto error; 129 130 /* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */ 131 err = ps8622_set(cl, 0x04, 0x71, 0x2d); 132 if (err) 133 goto error; 134 135 /* 2.7G CDR settings: NOF=40LSB for HBR CDR setting */ 136 err = ps8622_set(cl, 0x04, 0x7d, 0x07); 137 if (err) 138 goto error; 139 140 /* [1:0] Fmin=+4bands */ 141 err = ps8622_set(cl, 0x04, 0x7b, 0x00); 142 if (err) 143 goto error; 144 145 /* [7:5] DCO_FTRNG=+-40% */ 146 err = ps8622_set(cl, 0x04, 0x7a, 0xfd); 147 if (err) 148 goto error; 149 150 /* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */ 151 err = ps8622_set(cl, 0x04, 0xc0, 0x12); 152 if (err) 153 goto error; 154 155 /* Gitune=-37% */ 156 err = ps8622_set(cl, 0x04, 0xc1, 0x92); 157 if (err) 158 goto error; 159 160 /* Fbstep=100% */ 161 err = ps8622_set(cl, 0x04, 0xc2, 0x1c); 162 if (err) 163 goto error; 164 165 /* [7] LOS signal disable */ 166 err = ps8622_set(cl, 0x04, 0x32, 0x80); 167 if (err) 168 goto error; 169 170 /* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */ 171 err = ps8622_set(cl, 0x04, 0x00, 0xb0); 172 if (err) 173 goto error; 174 175 /* [7:6] Right-bar GPIO output strength is 8mA */ 176 err = ps8622_set(cl, 0x04, 0x15, 0x40); 177 if (err) 178 goto error; 179 180 /* EQ Training State Machine Setting, RCO calibration start */ 181 err = ps8622_set(cl, 0x04, 0x54, 0x10); 182 if (err) 183 goto error; 184 185 /* Logic, needs more than 10 I2C command */ 186 /* [4:0] MAX_LANE_COUNT set to max supported lanes */ 187 err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count); 188 if (err) 189 goto error; 190 191 /* [4:0] LANE_COUNT_SET set to chosen lane count */ 192 err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count); 193 if (err) 194 goto error; 195 196 err = ps8622_set(cl, 0x00, 0x52, 0x20); 197 if (err) 198 goto error; 199 200 /* HPD CP toggle enable */ 201 err = ps8622_set(cl, 0x00, 0xf1, 0x03); 202 if (err) 203 goto error; 204 205 err = ps8622_set(cl, 0x00, 0x62, 0x41); 206 if (err) 207 goto error; 208 209 /* Counter number, add 1ms counter delay */ 210 err = ps8622_set(cl, 0x00, 0xf6, 0x01); 211 if (err) 212 goto error; 213 214 /* [6]PWM function control by DPCD0040f[7], default is PWM block */ 215 err = ps8622_set(cl, 0x00, 0x77, 0x06); 216 if (err) 217 goto error; 218 219 /* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */ 220 err = ps8622_set(cl, 0x00, 0x4c, 0x04); 221 if (err) 222 goto error; 223 224 /* DPCD00400='h00, Parade OUI ='h001cf8 */ 225 err = ps8622_set(cl, 0x01, 0xc0, 0x00); 226 if (err) 227 goto error; 228 229 /* DPCD00401='h1c */ 230 err = ps8622_set(cl, 0x01, 0xc1, 0x1c); 231 if (err) 232 goto error; 233 234 /* DPCD00402='hf8 */ 235 err = ps8622_set(cl, 0x01, 0xc2, 0xf8); 236 if (err) 237 goto error; 238 239 /* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */ 240 err = ps8622_set(cl, 0x01, 0xc3, 0x44); 241 if (err) 242 goto error; 243 244 /* DPCD404 */ 245 err = ps8622_set(cl, 0x01, 0xc4, 0x32); 246 if (err) 247 goto error; 248 249 /* DPCD405 */ 250 err = ps8622_set(cl, 0x01, 0xc5, 0x53); 251 if (err) 252 goto error; 253 254 /* DPCD406 */ 255 err = ps8622_set(cl, 0x01, 0xc6, 0x4c); 256 if (err) 257 goto error; 258 259 /* DPCD407 */ 260 err = ps8622_set(cl, 0x01, 0xc7, 0x56); 261 if (err) 262 goto error; 263 264 /* DPCD408 */ 265 err = ps8622_set(cl, 0x01, 0xc8, 0x35); 266 if (err) 267 goto error; 268 269 /* DPCD40A, Initial Code major revision '01' */ 270 err = ps8622_set(cl, 0x01, 0xca, 0x01); 271 if (err) 272 goto error; 273 274 /* DPCD40B, Initial Code minor revision '05' */ 275 err = ps8622_set(cl, 0x01, 0xcb, 0x05); 276 if (err) 277 goto error; 278 279 280 if (ps8622->bl) { 281 /* DPCD720, internal PWM */ 282 err = ps8622_set(cl, 0x01, 0xa5, 0xa0); 283 if (err) 284 goto error; 285 286 /* FFh for 100% brightness, 0h for 0% brightness */ 287 err = ps8622_set(cl, 0x01, 0xa7, 288 ps8622->bl->props.brightness); 289 if (err) 290 goto error; 291 } else { 292 /* DPCD720, external PWM */ 293 err = ps8622_set(cl, 0x01, 0xa5, 0x80); 294 if (err) 295 goto error; 296 } 297 298 /* Set LVDS output as 6bit-VESA mapping, single LVDS channel */ 299 err = ps8622_set(cl, 0x01, 0xcc, 0x13); 300 if (err) 301 goto error; 302 303 /* Enable SSC set by register */ 304 err = ps8622_set(cl, 0x02, 0xb1, 0x20); 305 if (err) 306 goto error; 307 308 /* Set SSC enabled and +/-1% central spreading */ 309 err = ps8622_set(cl, 0x04, 0x10, 0x16); 310 if (err) 311 goto error; 312 313 /* Logic end */ 314 /* MPU Clock source: LC => RCO */ 315 err = ps8622_set(cl, 0x04, 0x59, 0x60); 316 if (err) 317 goto error; 318 319 /* LC -> RCO */ 320 err = ps8622_set(cl, 0x04, 0x54, 0x14); 321 if (err) 322 goto error; 323 324 /* HPD high */ 325 err = ps8622_set(cl, 0x02, 0xa1, 0x91); 326 327 error: 328 return err ? -EIO : 0; 329 } 330 331 static int ps8622_backlight_update(struct backlight_device *bl) 332 { 333 struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev); 334 int ret, brightness = bl->props.brightness; 335 336 if (bl->props.power != FB_BLANK_UNBLANK || 337 bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK)) 338 brightness = 0; 339 340 if (!ps8622->enabled) 341 return -EINVAL; 342 343 ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness); 344 345 return ret; 346 } 347 348 static const struct backlight_ops ps8622_backlight_ops = { 349 .update_status = ps8622_backlight_update, 350 }; 351 352 static void ps8622_pre_enable(struct drm_bridge *bridge) 353 { 354 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 355 int ret; 356 357 if (ps8622->enabled) 358 return; 359 360 gpiod_set_value(ps8622->gpio_rst, 0); 361 362 if (ps8622->v12) { 363 ret = regulator_enable(ps8622->v12); 364 if (ret) 365 DRM_ERROR("fails to enable ps8622->v12"); 366 } 367 368 if (drm_panel_prepare(ps8622->panel)) { 369 DRM_ERROR("failed to prepare panel\n"); 370 return; 371 } 372 373 gpiod_set_value(ps8622->gpio_slp, 1); 374 375 /* 376 * T1 is the range of time that it takes for the power to rise after we 377 * enable the lcd/ps8622 fet. T2 is the range of time in which the 378 * data sheet specifies we should deassert the reset pin. 379 * 380 * If it takes T1.max for the power to rise, we need to wait atleast 381 * T2.min before deasserting the reset pin. If it takes T1.min for the 382 * power to rise, we need to wait at most T2.max before deasserting the 383 * reset pin. 384 */ 385 usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US, 386 PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US); 387 388 gpiod_set_value(ps8622->gpio_rst, 1); 389 390 /* wait 20ms after RST high */ 391 usleep_range(20000, 30000); 392 393 ret = ps8622_send_config(ps8622); 394 if (ret) { 395 DRM_ERROR("Failed to send config to bridge (%d)\n", ret); 396 return; 397 } 398 399 ps8622->enabled = true; 400 } 401 402 static void ps8622_enable(struct drm_bridge *bridge) 403 { 404 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 405 406 if (drm_panel_enable(ps8622->panel)) { 407 DRM_ERROR("failed to enable panel\n"); 408 return; 409 } 410 } 411 412 static void ps8622_disable(struct drm_bridge *bridge) 413 { 414 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 415 416 if (drm_panel_disable(ps8622->panel)) { 417 DRM_ERROR("failed to disable panel\n"); 418 return; 419 } 420 msleep(PS8622_PWMO_END_T12_MS); 421 } 422 423 static void ps8622_post_disable(struct drm_bridge *bridge) 424 { 425 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 426 427 if (!ps8622->enabled) 428 return; 429 430 ps8622->enabled = false; 431 432 /* 433 * This doesn't matter if the regulators are turned off, but something 434 * else might keep them on. In that case, we want to assert the slp gpio 435 * to lower power. 436 */ 437 gpiod_set_value(ps8622->gpio_slp, 0); 438 439 if (drm_panel_unprepare(ps8622->panel)) { 440 DRM_ERROR("failed to unprepare panel\n"); 441 return; 442 } 443 444 if (ps8622->v12) 445 regulator_disable(ps8622->v12); 446 447 /* 448 * Sleep for at least the amount of time that it takes the power rail to 449 * fall to prevent asserting the rst gpio from doing anything. 450 */ 451 usleep_range(PS8622_POWER_FALL_T16_MAX_US, 452 2 * PS8622_POWER_FALL_T16_MAX_US); 453 gpiod_set_value(ps8622->gpio_rst, 0); 454 455 msleep(PS8622_POWER_OFF_T17_MS); 456 } 457 458 static int ps8622_get_modes(struct drm_connector *connector) 459 { 460 struct ps8622_bridge *ps8622; 461 462 ps8622 = connector_to_ps8622(connector); 463 464 return drm_panel_get_modes(ps8622->panel); 465 } 466 467 static const struct drm_connector_helper_funcs ps8622_connector_helper_funcs = { 468 .get_modes = ps8622_get_modes, 469 }; 470 471 static const struct drm_connector_funcs ps8622_connector_funcs = { 472 .fill_modes = drm_helper_probe_single_connector_modes, 473 .destroy = drm_connector_cleanup, 474 .reset = drm_atomic_helper_connector_reset, 475 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, 476 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, 477 }; 478 479 static int ps8622_attach(struct drm_bridge *bridge) 480 { 481 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 482 int ret; 483 484 if (!bridge->encoder) { 485 DRM_ERROR("Parent encoder object not found"); 486 return -ENODEV; 487 } 488 489 ps8622->connector.polled = DRM_CONNECTOR_POLL_HPD; 490 ret = drm_connector_init(bridge->dev, &ps8622->connector, 491 &ps8622_connector_funcs, DRM_MODE_CONNECTOR_LVDS); 492 if (ret) { 493 DRM_ERROR("Failed to initialize connector with drm\n"); 494 return ret; 495 } 496 drm_connector_helper_add(&ps8622->connector, 497 &ps8622_connector_helper_funcs); 498 drm_connector_register(&ps8622->connector); 499 drm_connector_attach_encoder(&ps8622->connector, 500 bridge->encoder); 501 502 if (ps8622->panel) 503 drm_panel_attach(ps8622->panel, &ps8622->connector); 504 505 drm_helper_hpd_irq_event(ps8622->connector.dev); 506 507 return ret; 508 } 509 510 static const struct drm_bridge_funcs ps8622_bridge_funcs = { 511 .pre_enable = ps8622_pre_enable, 512 .enable = ps8622_enable, 513 .disable = ps8622_disable, 514 .post_disable = ps8622_post_disable, 515 .attach = ps8622_attach, 516 }; 517 518 static const struct of_device_id ps8622_devices[] = { 519 {.compatible = "parade,ps8622",}, 520 {.compatible = "parade,ps8625",}, 521 {} 522 }; 523 MODULE_DEVICE_TABLE(of, ps8622_devices); 524 525 static int ps8622_probe(struct i2c_client *client, 526 const struct i2c_device_id *id) 527 { 528 struct device *dev = &client->dev; 529 struct ps8622_bridge *ps8622; 530 int ret; 531 532 ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL); 533 if (!ps8622) 534 return -ENOMEM; 535 536 ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &ps8622->panel, NULL); 537 if (ret) 538 return ret; 539 540 ps8622->client = client; 541 542 ps8622->v12 = devm_regulator_get(dev, "vdd12"); 543 if (IS_ERR(ps8622->v12)) { 544 dev_info(dev, "no 1.2v regulator found for PS8622\n"); 545 ps8622->v12 = NULL; 546 } 547 548 ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH); 549 if (IS_ERR(ps8622->gpio_slp)) { 550 ret = PTR_ERR(ps8622->gpio_slp); 551 dev_err(dev, "cannot get gpio_slp %d\n", ret); 552 return ret; 553 } 554 555 /* 556 * Assert the reset pin high to avoid the bridge being 557 * initialized prematurely 558 */ 559 ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 560 if (IS_ERR(ps8622->gpio_rst)) { 561 ret = PTR_ERR(ps8622->gpio_rst); 562 dev_err(dev, "cannot get gpio_rst %d\n", ret); 563 return ret; 564 } 565 566 ps8622->max_lane_count = id->driver_data; 567 568 if (of_property_read_u32(dev->of_node, "lane-count", 569 &ps8622->lane_count)) { 570 ps8622->lane_count = ps8622->max_lane_count; 571 } else if (ps8622->lane_count > ps8622->max_lane_count) { 572 dev_info(dev, "lane-count property is too high," 573 "using max_lane_count\n"); 574 ps8622->lane_count = ps8622->max_lane_count; 575 } 576 577 if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) { 578 ps8622->bl = backlight_device_register("ps8622-backlight", 579 dev, ps8622, &ps8622_backlight_ops, 580 NULL); 581 if (IS_ERR(ps8622->bl)) { 582 DRM_ERROR("failed to register backlight\n"); 583 ret = PTR_ERR(ps8622->bl); 584 ps8622->bl = NULL; 585 return ret; 586 } 587 ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS; 588 ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS; 589 } 590 591 ps8622->bridge.funcs = &ps8622_bridge_funcs; 592 ps8622->bridge.of_node = dev->of_node; 593 drm_bridge_add(&ps8622->bridge); 594 595 i2c_set_clientdata(client, ps8622); 596 597 return 0; 598 } 599 600 static int ps8622_remove(struct i2c_client *client) 601 { 602 struct ps8622_bridge *ps8622 = i2c_get_clientdata(client); 603 604 backlight_device_unregister(ps8622->bl); 605 drm_bridge_remove(&ps8622->bridge); 606 607 return 0; 608 } 609 610 static const struct i2c_device_id ps8622_i2c_table[] = { 611 /* Device type, max_lane_count */ 612 {"ps8622", 1}, 613 {"ps8625", 2}, 614 {}, 615 }; 616 MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table); 617 618 static struct i2c_driver ps8622_driver = { 619 .id_table = ps8622_i2c_table, 620 .probe = ps8622_probe, 621 .remove = ps8622_remove, 622 .driver = { 623 .name = "ps8622", 624 .of_match_table = ps8622_devices, 625 }, 626 }; 627 module_i2c_driver(ps8622_driver); 628 629 MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>"); 630 MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver"); 631 MODULE_LICENSE("GPL v2"); 632