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 i2c_client *client; 46 struct drm_bridge bridge; 47 struct drm_bridge *panel_bridge; 48 struct regulator *v12; 49 struct backlight_device *bl; 50 51 struct gpio_desc *gpio_slp; 52 struct gpio_desc *gpio_rst; 53 54 u32 max_lane_count; 55 u32 lane_count; 56 57 bool enabled; 58 }; 59 60 static inline struct ps8622_bridge * 61 bridge_to_ps8622(struct drm_bridge *bridge) 62 { 63 return container_of(bridge, struct ps8622_bridge, bridge); 64 } 65 66 static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val) 67 { 68 int ret; 69 struct i2c_adapter *adap = client->adapter; 70 struct i2c_msg msg; 71 u8 data[] = {reg, val}; 72 73 msg.addr = client->addr + page; 74 msg.flags = 0; 75 msg.len = sizeof(data); 76 msg.buf = data; 77 78 ret = i2c_transfer(adap, &msg, 1); 79 if (ret != 1) 80 pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n", 81 client->addr + page, reg, val, ret); 82 return !(ret == 1); 83 } 84 85 static int ps8622_send_config(struct ps8622_bridge *ps8622) 86 { 87 struct i2c_client *cl = ps8622->client; 88 int err = 0; 89 90 /* HPD low */ 91 err = ps8622_set(cl, 0x02, 0xa1, 0x01); 92 if (err) 93 goto error; 94 95 /* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */ 96 err = ps8622_set(cl, 0x04, 0x14, 0x01); 97 if (err) 98 goto error; 99 100 /* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */ 101 err = ps8622_set(cl, 0x04, 0xe3, 0x20); 102 if (err) 103 goto error; 104 105 /* [7] RCO SS enable */ 106 err = ps8622_set(cl, 0x04, 0xe2, 0x80); 107 if (err) 108 goto error; 109 110 /* RPHY Setting 111 * [3:2] CDR tune wait cycle before measure for fine tune 112 * b00: 1us b01: 0.5us b10:2us, b11: 4us 113 */ 114 err = ps8622_set(cl, 0x04, 0x8a, 0x0c); 115 if (err) 116 goto error; 117 118 /* [3] RFD always on */ 119 err = ps8622_set(cl, 0x04, 0x89, 0x08); 120 if (err) 121 goto error; 122 123 /* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */ 124 err = ps8622_set(cl, 0x04, 0x71, 0x2d); 125 if (err) 126 goto error; 127 128 /* 2.7G CDR settings: NOF=40LSB for HBR CDR setting */ 129 err = ps8622_set(cl, 0x04, 0x7d, 0x07); 130 if (err) 131 goto error; 132 133 /* [1:0] Fmin=+4bands */ 134 err = ps8622_set(cl, 0x04, 0x7b, 0x00); 135 if (err) 136 goto error; 137 138 /* [7:5] DCO_FTRNG=+-40% */ 139 err = ps8622_set(cl, 0x04, 0x7a, 0xfd); 140 if (err) 141 goto error; 142 143 /* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */ 144 err = ps8622_set(cl, 0x04, 0xc0, 0x12); 145 if (err) 146 goto error; 147 148 /* Gitune=-37% */ 149 err = ps8622_set(cl, 0x04, 0xc1, 0x92); 150 if (err) 151 goto error; 152 153 /* Fbstep=100% */ 154 err = ps8622_set(cl, 0x04, 0xc2, 0x1c); 155 if (err) 156 goto error; 157 158 /* [7] LOS signal disable */ 159 err = ps8622_set(cl, 0x04, 0x32, 0x80); 160 if (err) 161 goto error; 162 163 /* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */ 164 err = ps8622_set(cl, 0x04, 0x00, 0xb0); 165 if (err) 166 goto error; 167 168 /* [7:6] Right-bar GPIO output strength is 8mA */ 169 err = ps8622_set(cl, 0x04, 0x15, 0x40); 170 if (err) 171 goto error; 172 173 /* EQ Training State Machine Setting, RCO calibration start */ 174 err = ps8622_set(cl, 0x04, 0x54, 0x10); 175 if (err) 176 goto error; 177 178 /* Logic, needs more than 10 I2C command */ 179 /* [4:0] MAX_LANE_COUNT set to max supported lanes */ 180 err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count); 181 if (err) 182 goto error; 183 184 /* [4:0] LANE_COUNT_SET set to chosen lane count */ 185 err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count); 186 if (err) 187 goto error; 188 189 err = ps8622_set(cl, 0x00, 0x52, 0x20); 190 if (err) 191 goto error; 192 193 /* HPD CP toggle enable */ 194 err = ps8622_set(cl, 0x00, 0xf1, 0x03); 195 if (err) 196 goto error; 197 198 err = ps8622_set(cl, 0x00, 0x62, 0x41); 199 if (err) 200 goto error; 201 202 /* Counter number, add 1ms counter delay */ 203 err = ps8622_set(cl, 0x00, 0xf6, 0x01); 204 if (err) 205 goto error; 206 207 /* [6]PWM function control by DPCD0040f[7], default is PWM block */ 208 err = ps8622_set(cl, 0x00, 0x77, 0x06); 209 if (err) 210 goto error; 211 212 /* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */ 213 err = ps8622_set(cl, 0x00, 0x4c, 0x04); 214 if (err) 215 goto error; 216 217 /* DPCD00400='h00, Parade OUI ='h001cf8 */ 218 err = ps8622_set(cl, 0x01, 0xc0, 0x00); 219 if (err) 220 goto error; 221 222 /* DPCD00401='h1c */ 223 err = ps8622_set(cl, 0x01, 0xc1, 0x1c); 224 if (err) 225 goto error; 226 227 /* DPCD00402='hf8 */ 228 err = ps8622_set(cl, 0x01, 0xc2, 0xf8); 229 if (err) 230 goto error; 231 232 /* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */ 233 err = ps8622_set(cl, 0x01, 0xc3, 0x44); 234 if (err) 235 goto error; 236 237 /* DPCD404 */ 238 err = ps8622_set(cl, 0x01, 0xc4, 0x32); 239 if (err) 240 goto error; 241 242 /* DPCD405 */ 243 err = ps8622_set(cl, 0x01, 0xc5, 0x53); 244 if (err) 245 goto error; 246 247 /* DPCD406 */ 248 err = ps8622_set(cl, 0x01, 0xc6, 0x4c); 249 if (err) 250 goto error; 251 252 /* DPCD407 */ 253 err = ps8622_set(cl, 0x01, 0xc7, 0x56); 254 if (err) 255 goto error; 256 257 /* DPCD408 */ 258 err = ps8622_set(cl, 0x01, 0xc8, 0x35); 259 if (err) 260 goto error; 261 262 /* DPCD40A, Initial Code major revision '01' */ 263 err = ps8622_set(cl, 0x01, 0xca, 0x01); 264 if (err) 265 goto error; 266 267 /* DPCD40B, Initial Code minor revision '05' */ 268 err = ps8622_set(cl, 0x01, 0xcb, 0x05); 269 if (err) 270 goto error; 271 272 273 if (ps8622->bl) { 274 /* DPCD720, internal PWM */ 275 err = ps8622_set(cl, 0x01, 0xa5, 0xa0); 276 if (err) 277 goto error; 278 279 /* FFh for 100% brightness, 0h for 0% brightness */ 280 err = ps8622_set(cl, 0x01, 0xa7, 281 ps8622->bl->props.brightness); 282 if (err) 283 goto error; 284 } else { 285 /* DPCD720, external PWM */ 286 err = ps8622_set(cl, 0x01, 0xa5, 0x80); 287 if (err) 288 goto error; 289 } 290 291 /* Set LVDS output as 6bit-VESA mapping, single LVDS channel */ 292 err = ps8622_set(cl, 0x01, 0xcc, 0x13); 293 if (err) 294 goto error; 295 296 /* Enable SSC set by register */ 297 err = ps8622_set(cl, 0x02, 0xb1, 0x20); 298 if (err) 299 goto error; 300 301 /* Set SSC enabled and +/-1% central spreading */ 302 err = ps8622_set(cl, 0x04, 0x10, 0x16); 303 if (err) 304 goto error; 305 306 /* Logic end */ 307 /* MPU Clock source: LC => RCO */ 308 err = ps8622_set(cl, 0x04, 0x59, 0x60); 309 if (err) 310 goto error; 311 312 /* LC -> RCO */ 313 err = ps8622_set(cl, 0x04, 0x54, 0x14); 314 if (err) 315 goto error; 316 317 /* HPD high */ 318 err = ps8622_set(cl, 0x02, 0xa1, 0x91); 319 320 error: 321 return err ? -EIO : 0; 322 } 323 324 static int ps8622_backlight_update(struct backlight_device *bl) 325 { 326 struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev); 327 int ret, brightness = backlight_get_brightness(bl); 328 329 if (!ps8622->enabled) 330 return -EINVAL; 331 332 ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness); 333 334 return ret; 335 } 336 337 static const struct backlight_ops ps8622_backlight_ops = { 338 .update_status = ps8622_backlight_update, 339 }; 340 341 static void ps8622_pre_enable(struct drm_bridge *bridge) 342 { 343 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 344 int ret; 345 346 if (ps8622->enabled) 347 return; 348 349 gpiod_set_value(ps8622->gpio_rst, 0); 350 351 if (ps8622->v12) { 352 ret = regulator_enable(ps8622->v12); 353 if (ret) 354 DRM_ERROR("fails to enable ps8622->v12"); 355 } 356 357 gpiod_set_value(ps8622->gpio_slp, 1); 358 359 /* 360 * T1 is the range of time that it takes for the power to rise after we 361 * enable the lcd/ps8622 fet. T2 is the range of time in which the 362 * data sheet specifies we should deassert the reset pin. 363 * 364 * If it takes T1.max for the power to rise, we need to wait atleast 365 * T2.min before deasserting the reset pin. If it takes T1.min for the 366 * power to rise, we need to wait at most T2.max before deasserting the 367 * reset pin. 368 */ 369 usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US, 370 PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US); 371 372 gpiod_set_value(ps8622->gpio_rst, 1); 373 374 /* wait 20ms after RST high */ 375 usleep_range(20000, 30000); 376 377 ret = ps8622_send_config(ps8622); 378 if (ret) { 379 DRM_ERROR("Failed to send config to bridge (%d)\n", ret); 380 return; 381 } 382 383 ps8622->enabled = true; 384 } 385 386 static void ps8622_disable(struct drm_bridge *bridge) 387 { 388 /* Delay after panel is disabled */ 389 msleep(PS8622_PWMO_END_T12_MS); 390 } 391 392 static void ps8622_post_disable(struct drm_bridge *bridge) 393 { 394 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 395 396 if (!ps8622->enabled) 397 return; 398 399 ps8622->enabled = false; 400 401 /* 402 * This doesn't matter if the regulators are turned off, but something 403 * else might keep them on. In that case, we want to assert the slp gpio 404 * to lower power. 405 */ 406 gpiod_set_value(ps8622->gpio_slp, 0); 407 408 if (ps8622->v12) 409 regulator_disable(ps8622->v12); 410 411 /* 412 * Sleep for at least the amount of time that it takes the power rail to 413 * fall to prevent asserting the rst gpio from doing anything. 414 */ 415 usleep_range(PS8622_POWER_FALL_T16_MAX_US, 416 2 * PS8622_POWER_FALL_T16_MAX_US); 417 gpiod_set_value(ps8622->gpio_rst, 0); 418 419 msleep(PS8622_POWER_OFF_T17_MS); 420 } 421 422 static int ps8622_attach(struct drm_bridge *bridge, 423 enum drm_bridge_attach_flags flags) 424 { 425 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 426 427 return drm_bridge_attach(ps8622->bridge.encoder, ps8622->panel_bridge, 428 &ps8622->bridge, flags); 429 } 430 431 static const struct drm_bridge_funcs ps8622_bridge_funcs = { 432 .pre_enable = ps8622_pre_enable, 433 .disable = ps8622_disable, 434 .post_disable = ps8622_post_disable, 435 .attach = ps8622_attach, 436 }; 437 438 static const struct of_device_id ps8622_devices[] = { 439 {.compatible = "parade,ps8622",}, 440 {.compatible = "parade,ps8625",}, 441 {} 442 }; 443 MODULE_DEVICE_TABLE(of, ps8622_devices); 444 445 static int ps8622_probe(struct i2c_client *client) 446 { 447 const struct i2c_device_id *id = i2c_client_get_device_id(client); 448 struct device *dev = &client->dev; 449 struct ps8622_bridge *ps8622; 450 struct drm_bridge *panel_bridge; 451 int ret; 452 453 ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL); 454 if (!ps8622) 455 return -ENOMEM; 456 457 panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0); 458 if (IS_ERR(panel_bridge)) 459 return PTR_ERR(panel_bridge); 460 461 ps8622->panel_bridge = panel_bridge; 462 ps8622->client = client; 463 464 ps8622->v12 = devm_regulator_get(dev, "vdd12"); 465 if (IS_ERR(ps8622->v12)) { 466 dev_info(dev, "no 1.2v regulator found for PS8622\n"); 467 ps8622->v12 = NULL; 468 } 469 470 ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH); 471 if (IS_ERR(ps8622->gpio_slp)) { 472 ret = PTR_ERR(ps8622->gpio_slp); 473 dev_err(dev, "cannot get gpio_slp %d\n", ret); 474 return ret; 475 } 476 477 /* 478 * Assert the reset pin high to avoid the bridge being 479 * initialized prematurely 480 */ 481 ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 482 if (IS_ERR(ps8622->gpio_rst)) { 483 ret = PTR_ERR(ps8622->gpio_rst); 484 dev_err(dev, "cannot get gpio_rst %d\n", ret); 485 return ret; 486 } 487 488 ps8622->max_lane_count = id->driver_data; 489 490 if (of_property_read_u32(dev->of_node, "lane-count", 491 &ps8622->lane_count)) { 492 ps8622->lane_count = ps8622->max_lane_count; 493 } else if (ps8622->lane_count > ps8622->max_lane_count) { 494 dev_info(dev, "lane-count property is too high," 495 "using max_lane_count\n"); 496 ps8622->lane_count = ps8622->max_lane_count; 497 } 498 499 if (!of_property_read_bool(dev->of_node, "use-external-pwm")) { 500 ps8622->bl = backlight_device_register("ps8622-backlight", 501 dev, ps8622, &ps8622_backlight_ops, 502 NULL); 503 if (IS_ERR(ps8622->bl)) { 504 DRM_ERROR("failed to register backlight\n"); 505 ret = PTR_ERR(ps8622->bl); 506 ps8622->bl = NULL; 507 return ret; 508 } 509 ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS; 510 ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS; 511 } 512 513 ps8622->bridge.funcs = &ps8622_bridge_funcs; 514 ps8622->bridge.type = DRM_MODE_CONNECTOR_LVDS; 515 ps8622->bridge.of_node = dev->of_node; 516 drm_bridge_add(&ps8622->bridge); 517 518 i2c_set_clientdata(client, ps8622); 519 520 return 0; 521 } 522 523 static void ps8622_remove(struct i2c_client *client) 524 { 525 struct ps8622_bridge *ps8622 = i2c_get_clientdata(client); 526 527 backlight_device_unregister(ps8622->bl); 528 drm_bridge_remove(&ps8622->bridge); 529 } 530 531 static const struct i2c_device_id ps8622_i2c_table[] = { 532 /* Device type, max_lane_count */ 533 {"ps8622", 1}, 534 {"ps8625", 2}, 535 {}, 536 }; 537 MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table); 538 539 static struct i2c_driver ps8622_driver = { 540 .id_table = ps8622_i2c_table, 541 .probe_new = ps8622_probe, 542 .remove = ps8622_remove, 543 .driver = { 544 .name = "ps8622", 545 .of_match_table = ps8622_devices, 546 }, 547 }; 548 module_i2c_driver(ps8622_driver); 549 550 MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>"); 551 MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver"); 552 MODULE_LICENSE("GPL v2"); 553