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/pm.h> 16 #include <linux/regulator/consumer.h> 17 18 #include <drm/drm_atomic_helper.h> 19 #include <drm/drm_bridge.h> 20 #include <drm/drm_crtc.h> 21 #include <drm/drm_of.h> 22 #include <drm/drm_panel.h> 23 #include <drm/drm_print.h> 24 #include <drm/drm_probe_helper.h> 25 26 /* Brightness scale on the Parade chip */ 27 #define PS8622_MAX_BRIGHTNESS 0xff 28 29 /* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */ 30 #define PS8622_POWER_RISE_T1_MIN_US 10 31 #define PS8622_POWER_RISE_T1_MAX_US 10000 32 #define PS8622_RST_HIGH_T2_MIN_US 3000 33 #define PS8622_RST_HIGH_T2_MAX_US 30000 34 #define PS8622_PWMO_END_T12_MS 200 35 #define PS8622_POWER_FALL_T16_MAX_US 10000 36 #define PS8622_POWER_OFF_T17_MS 500 37 38 #if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \ 39 (PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US)) 40 #error "T2.min + T1.max must be less than T2.max + T1.min" 41 #endif 42 43 struct ps8622_bridge { 44 struct i2c_client *client; 45 struct drm_bridge bridge; 46 struct drm_bridge *panel_bridge; 47 struct regulator *v12; 48 struct backlight_device *bl; 49 50 struct gpio_desc *gpio_slp; 51 struct gpio_desc *gpio_rst; 52 53 u32 max_lane_count; 54 u32 lane_count; 55 56 bool enabled; 57 }; 58 59 static inline struct ps8622_bridge * 60 bridge_to_ps8622(struct drm_bridge *bridge) 61 { 62 return container_of(bridge, struct ps8622_bridge, bridge); 63 } 64 65 static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val) 66 { 67 int ret; 68 struct i2c_adapter *adap = client->adapter; 69 struct i2c_msg msg; 70 u8 data[] = {reg, val}; 71 72 msg.addr = client->addr + page; 73 msg.flags = 0; 74 msg.len = sizeof(data); 75 msg.buf = data; 76 77 ret = i2c_transfer(adap, &msg, 1); 78 if (ret != 1) 79 pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n", 80 client->addr + page, reg, val, ret); 81 return !(ret == 1); 82 } 83 84 static int ps8622_send_config(struct ps8622_bridge *ps8622) 85 { 86 struct i2c_client *cl = ps8622->client; 87 int err = 0; 88 89 /* HPD low */ 90 err = ps8622_set(cl, 0x02, 0xa1, 0x01); 91 if (err) 92 goto error; 93 94 /* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */ 95 err = ps8622_set(cl, 0x04, 0x14, 0x01); 96 if (err) 97 goto error; 98 99 /* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */ 100 err = ps8622_set(cl, 0x04, 0xe3, 0x20); 101 if (err) 102 goto error; 103 104 /* [7] RCO SS enable */ 105 err = ps8622_set(cl, 0x04, 0xe2, 0x80); 106 if (err) 107 goto error; 108 109 /* RPHY Setting 110 * [3:2] CDR tune wait cycle before measure for fine tune 111 * b00: 1us b01: 0.5us b10:2us, b11: 4us 112 */ 113 err = ps8622_set(cl, 0x04, 0x8a, 0x0c); 114 if (err) 115 goto error; 116 117 /* [3] RFD always on */ 118 err = ps8622_set(cl, 0x04, 0x89, 0x08); 119 if (err) 120 goto error; 121 122 /* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */ 123 err = ps8622_set(cl, 0x04, 0x71, 0x2d); 124 if (err) 125 goto error; 126 127 /* 2.7G CDR settings: NOF=40LSB for HBR CDR setting */ 128 err = ps8622_set(cl, 0x04, 0x7d, 0x07); 129 if (err) 130 goto error; 131 132 /* [1:0] Fmin=+4bands */ 133 err = ps8622_set(cl, 0x04, 0x7b, 0x00); 134 if (err) 135 goto error; 136 137 /* [7:5] DCO_FTRNG=+-40% */ 138 err = ps8622_set(cl, 0x04, 0x7a, 0xfd); 139 if (err) 140 goto error; 141 142 /* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */ 143 err = ps8622_set(cl, 0x04, 0xc0, 0x12); 144 if (err) 145 goto error; 146 147 /* Gitune=-37% */ 148 err = ps8622_set(cl, 0x04, 0xc1, 0x92); 149 if (err) 150 goto error; 151 152 /* Fbstep=100% */ 153 err = ps8622_set(cl, 0x04, 0xc2, 0x1c); 154 if (err) 155 goto error; 156 157 /* [7] LOS signal disable */ 158 err = ps8622_set(cl, 0x04, 0x32, 0x80); 159 if (err) 160 goto error; 161 162 /* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */ 163 err = ps8622_set(cl, 0x04, 0x00, 0xb0); 164 if (err) 165 goto error; 166 167 /* [7:6] Right-bar GPIO output strength is 8mA */ 168 err = ps8622_set(cl, 0x04, 0x15, 0x40); 169 if (err) 170 goto error; 171 172 /* EQ Training State Machine Setting, RCO calibration start */ 173 err = ps8622_set(cl, 0x04, 0x54, 0x10); 174 if (err) 175 goto error; 176 177 /* Logic, needs more than 10 I2C command */ 178 /* [4:0] MAX_LANE_COUNT set to max supported lanes */ 179 err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count); 180 if (err) 181 goto error; 182 183 /* [4:0] LANE_COUNT_SET set to chosen lane count */ 184 err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count); 185 if (err) 186 goto error; 187 188 err = ps8622_set(cl, 0x00, 0x52, 0x20); 189 if (err) 190 goto error; 191 192 /* HPD CP toggle enable */ 193 err = ps8622_set(cl, 0x00, 0xf1, 0x03); 194 if (err) 195 goto error; 196 197 err = ps8622_set(cl, 0x00, 0x62, 0x41); 198 if (err) 199 goto error; 200 201 /* Counter number, add 1ms counter delay */ 202 err = ps8622_set(cl, 0x00, 0xf6, 0x01); 203 if (err) 204 goto error; 205 206 /* [6]PWM function control by DPCD0040f[7], default is PWM block */ 207 err = ps8622_set(cl, 0x00, 0x77, 0x06); 208 if (err) 209 goto error; 210 211 /* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */ 212 err = ps8622_set(cl, 0x00, 0x4c, 0x04); 213 if (err) 214 goto error; 215 216 /* DPCD00400='h00, Parade OUI ='h001cf8 */ 217 err = ps8622_set(cl, 0x01, 0xc0, 0x00); 218 if (err) 219 goto error; 220 221 /* DPCD00401='h1c */ 222 err = ps8622_set(cl, 0x01, 0xc1, 0x1c); 223 if (err) 224 goto error; 225 226 /* DPCD00402='hf8 */ 227 err = ps8622_set(cl, 0x01, 0xc2, 0xf8); 228 if (err) 229 goto error; 230 231 /* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */ 232 err = ps8622_set(cl, 0x01, 0xc3, 0x44); 233 if (err) 234 goto error; 235 236 /* DPCD404 */ 237 err = ps8622_set(cl, 0x01, 0xc4, 0x32); 238 if (err) 239 goto error; 240 241 /* DPCD405 */ 242 err = ps8622_set(cl, 0x01, 0xc5, 0x53); 243 if (err) 244 goto error; 245 246 /* DPCD406 */ 247 err = ps8622_set(cl, 0x01, 0xc6, 0x4c); 248 if (err) 249 goto error; 250 251 /* DPCD407 */ 252 err = ps8622_set(cl, 0x01, 0xc7, 0x56); 253 if (err) 254 goto error; 255 256 /* DPCD408 */ 257 err = ps8622_set(cl, 0x01, 0xc8, 0x35); 258 if (err) 259 goto error; 260 261 /* DPCD40A, Initial Code major revision '01' */ 262 err = ps8622_set(cl, 0x01, 0xca, 0x01); 263 if (err) 264 goto error; 265 266 /* DPCD40B, Initial Code minor revision '05' */ 267 err = ps8622_set(cl, 0x01, 0xcb, 0x05); 268 if (err) 269 goto error; 270 271 272 if (ps8622->bl) { 273 /* DPCD720, internal PWM */ 274 err = ps8622_set(cl, 0x01, 0xa5, 0xa0); 275 if (err) 276 goto error; 277 278 /* FFh for 100% brightness, 0h for 0% brightness */ 279 err = ps8622_set(cl, 0x01, 0xa7, 280 ps8622->bl->props.brightness); 281 if (err) 282 goto error; 283 } else { 284 /* DPCD720, external PWM */ 285 err = ps8622_set(cl, 0x01, 0xa5, 0x80); 286 if (err) 287 goto error; 288 } 289 290 /* Set LVDS output as 6bit-VESA mapping, single LVDS channel */ 291 err = ps8622_set(cl, 0x01, 0xcc, 0x13); 292 if (err) 293 goto error; 294 295 /* Enable SSC set by register */ 296 err = ps8622_set(cl, 0x02, 0xb1, 0x20); 297 if (err) 298 goto error; 299 300 /* Set SSC enabled and +/-1% central spreading */ 301 err = ps8622_set(cl, 0x04, 0x10, 0x16); 302 if (err) 303 goto error; 304 305 /* Logic end */ 306 /* MPU Clock source: LC => RCO */ 307 err = ps8622_set(cl, 0x04, 0x59, 0x60); 308 if (err) 309 goto error; 310 311 /* LC -> RCO */ 312 err = ps8622_set(cl, 0x04, 0x54, 0x14); 313 if (err) 314 goto error; 315 316 /* HPD high */ 317 err = ps8622_set(cl, 0x02, 0xa1, 0x91); 318 319 error: 320 return err ? -EIO : 0; 321 } 322 323 static int ps8622_backlight_update(struct backlight_device *bl) 324 { 325 struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev); 326 int ret, brightness = backlight_get_brightness(bl); 327 328 if (!ps8622->enabled) 329 return -EINVAL; 330 331 ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness); 332 333 return ret; 334 } 335 336 static const struct backlight_ops ps8622_backlight_ops = { 337 .update_status = ps8622_backlight_update, 338 }; 339 340 static void ps8622_pre_enable(struct drm_bridge *bridge) 341 { 342 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 343 int ret; 344 345 if (ps8622->enabled) 346 return; 347 348 gpiod_set_value(ps8622->gpio_rst, 0); 349 350 if (ps8622->v12) { 351 ret = regulator_enable(ps8622->v12); 352 if (ret) 353 DRM_ERROR("fails to enable ps8622->v12"); 354 } 355 356 gpiod_set_value(ps8622->gpio_slp, 1); 357 358 /* 359 * T1 is the range of time that it takes for the power to rise after we 360 * enable the lcd/ps8622 fet. T2 is the range of time in which the 361 * data sheet specifies we should deassert the reset pin. 362 * 363 * If it takes T1.max for the power to rise, we need to wait atleast 364 * T2.min before deasserting the reset pin. If it takes T1.min for the 365 * power to rise, we need to wait at most T2.max before deasserting the 366 * reset pin. 367 */ 368 usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US, 369 PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US); 370 371 gpiod_set_value(ps8622->gpio_rst, 1); 372 373 /* wait 20ms after RST high */ 374 usleep_range(20000, 30000); 375 376 ret = ps8622_send_config(ps8622); 377 if (ret) { 378 DRM_ERROR("Failed to send config to bridge (%d)\n", ret); 379 return; 380 } 381 382 ps8622->enabled = true; 383 } 384 385 static void ps8622_disable(struct drm_bridge *bridge) 386 { 387 /* Delay after panel is disabled */ 388 msleep(PS8622_PWMO_END_T12_MS); 389 } 390 391 static void ps8622_post_disable(struct drm_bridge *bridge) 392 { 393 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 394 395 if (!ps8622->enabled) 396 return; 397 398 ps8622->enabled = false; 399 400 /* 401 * This doesn't matter if the regulators are turned off, but something 402 * else might keep them on. In that case, we want to assert the slp gpio 403 * to lower power. 404 */ 405 gpiod_set_value(ps8622->gpio_slp, 0); 406 407 if (ps8622->v12) 408 regulator_disable(ps8622->v12); 409 410 /* 411 * Sleep for at least the amount of time that it takes the power rail to 412 * fall to prevent asserting the rst gpio from doing anything. 413 */ 414 usleep_range(PS8622_POWER_FALL_T16_MAX_US, 415 2 * PS8622_POWER_FALL_T16_MAX_US); 416 gpiod_set_value(ps8622->gpio_rst, 0); 417 418 msleep(PS8622_POWER_OFF_T17_MS); 419 } 420 421 static int ps8622_attach(struct drm_bridge *bridge, 422 enum drm_bridge_attach_flags flags) 423 { 424 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 425 426 return drm_bridge_attach(ps8622->bridge.encoder, ps8622->panel_bridge, 427 &ps8622->bridge, flags); 428 } 429 430 static const struct drm_bridge_funcs ps8622_bridge_funcs = { 431 .pre_enable = ps8622_pre_enable, 432 .disable = ps8622_disable, 433 .post_disable = ps8622_post_disable, 434 .attach = ps8622_attach, 435 }; 436 437 static const struct of_device_id ps8622_devices[] = { 438 {.compatible = "parade,ps8622",}, 439 {.compatible = "parade,ps8625",}, 440 {} 441 }; 442 MODULE_DEVICE_TABLE(of, ps8622_devices); 443 444 static int ps8622_probe(struct i2c_client *client) 445 { 446 const struct i2c_device_id *id = i2c_client_get_device_id(client); 447 struct device *dev = &client->dev; 448 struct ps8622_bridge *ps8622; 449 struct drm_bridge *panel_bridge; 450 int ret; 451 452 ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL); 453 if (!ps8622) 454 return -ENOMEM; 455 456 panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0); 457 if (IS_ERR(panel_bridge)) 458 return PTR_ERR(panel_bridge); 459 460 ps8622->panel_bridge = panel_bridge; 461 ps8622->client = client; 462 463 ps8622->v12 = devm_regulator_get(dev, "vdd12"); 464 if (IS_ERR(ps8622->v12)) { 465 dev_info(dev, "no 1.2v regulator found for PS8622\n"); 466 ps8622->v12 = NULL; 467 } 468 469 ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH); 470 if (IS_ERR(ps8622->gpio_slp)) { 471 ret = PTR_ERR(ps8622->gpio_slp); 472 dev_err(dev, "cannot get gpio_slp %d\n", ret); 473 return ret; 474 } 475 476 /* 477 * Assert the reset pin high to avoid the bridge being 478 * initialized prematurely 479 */ 480 ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 481 if (IS_ERR(ps8622->gpio_rst)) { 482 ret = PTR_ERR(ps8622->gpio_rst); 483 dev_err(dev, "cannot get gpio_rst %d\n", ret); 484 return ret; 485 } 486 487 ps8622->max_lane_count = id->driver_data; 488 489 if (of_property_read_u32(dev->of_node, "lane-count", 490 &ps8622->lane_count)) { 491 ps8622->lane_count = ps8622->max_lane_count; 492 } else if (ps8622->lane_count > ps8622->max_lane_count) { 493 dev_info(dev, "lane-count property is too high," 494 "using max_lane_count\n"); 495 ps8622->lane_count = ps8622->max_lane_count; 496 } 497 498 if (!of_property_read_bool(dev->of_node, "use-external-pwm")) { 499 ps8622->bl = backlight_device_register("ps8622-backlight", 500 dev, ps8622, &ps8622_backlight_ops, 501 NULL); 502 if (IS_ERR(ps8622->bl)) { 503 DRM_ERROR("failed to register backlight\n"); 504 ret = PTR_ERR(ps8622->bl); 505 ps8622->bl = NULL; 506 return ret; 507 } 508 ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS; 509 ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS; 510 } 511 512 ps8622->bridge.funcs = &ps8622_bridge_funcs; 513 ps8622->bridge.type = DRM_MODE_CONNECTOR_LVDS; 514 ps8622->bridge.of_node = dev->of_node; 515 drm_bridge_add(&ps8622->bridge); 516 517 i2c_set_clientdata(client, ps8622); 518 519 return 0; 520 } 521 522 static void ps8622_remove(struct i2c_client *client) 523 { 524 struct ps8622_bridge *ps8622 = i2c_get_clientdata(client); 525 526 backlight_device_unregister(ps8622->bl); 527 drm_bridge_remove(&ps8622->bridge); 528 } 529 530 static const struct i2c_device_id ps8622_i2c_table[] = { 531 /* Device type, max_lane_count */ 532 {"ps8622", 1}, 533 {"ps8625", 2}, 534 {}, 535 }; 536 MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table); 537 538 static struct i2c_driver ps8622_driver = { 539 .id_table = ps8622_i2c_table, 540 .probe = ps8622_probe, 541 .remove = ps8622_remove, 542 .driver = { 543 .name = "ps8622", 544 .of_match_table = ps8622_devices, 545 }, 546 }; 547 module_i2c_driver(ps8622_driver); 548 549 MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>"); 550 MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver"); 551 MODULE_LICENSE("GPL v2"); 552