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 = bl->props.brightness; 328 329 if (bl->props.power != FB_BLANK_UNBLANK || 330 bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK)) 331 brightness = 0; 332 333 if (!ps8622->enabled) 334 return -EINVAL; 335 336 ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness); 337 338 return ret; 339 } 340 341 static const struct backlight_ops ps8622_backlight_ops = { 342 .update_status = ps8622_backlight_update, 343 }; 344 345 static void ps8622_pre_enable(struct drm_bridge *bridge) 346 { 347 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 348 int ret; 349 350 if (ps8622->enabled) 351 return; 352 353 gpiod_set_value(ps8622->gpio_rst, 0); 354 355 if (ps8622->v12) { 356 ret = regulator_enable(ps8622->v12); 357 if (ret) 358 DRM_ERROR("fails to enable ps8622->v12"); 359 } 360 361 gpiod_set_value(ps8622->gpio_slp, 1); 362 363 /* 364 * T1 is the range of time that it takes for the power to rise after we 365 * enable the lcd/ps8622 fet. T2 is the range of time in which the 366 * data sheet specifies we should deassert the reset pin. 367 * 368 * If it takes T1.max for the power to rise, we need to wait atleast 369 * T2.min before deasserting the reset pin. If it takes T1.min for the 370 * power to rise, we need to wait at most T2.max before deasserting the 371 * reset pin. 372 */ 373 usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US, 374 PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US); 375 376 gpiod_set_value(ps8622->gpio_rst, 1); 377 378 /* wait 20ms after RST high */ 379 usleep_range(20000, 30000); 380 381 ret = ps8622_send_config(ps8622); 382 if (ret) { 383 DRM_ERROR("Failed to send config to bridge (%d)\n", ret); 384 return; 385 } 386 387 ps8622->enabled = true; 388 } 389 390 static void ps8622_disable(struct drm_bridge *bridge) 391 { 392 /* Delay after panel is disabled */ 393 msleep(PS8622_PWMO_END_T12_MS); 394 } 395 396 static void ps8622_post_disable(struct drm_bridge *bridge) 397 { 398 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 399 400 if (!ps8622->enabled) 401 return; 402 403 ps8622->enabled = false; 404 405 /* 406 * This doesn't matter if the regulators are turned off, but something 407 * else might keep them on. In that case, we want to assert the slp gpio 408 * to lower power. 409 */ 410 gpiod_set_value(ps8622->gpio_slp, 0); 411 412 if (ps8622->v12) 413 regulator_disable(ps8622->v12); 414 415 /* 416 * Sleep for at least the amount of time that it takes the power rail to 417 * fall to prevent asserting the rst gpio from doing anything. 418 */ 419 usleep_range(PS8622_POWER_FALL_T16_MAX_US, 420 2 * PS8622_POWER_FALL_T16_MAX_US); 421 gpiod_set_value(ps8622->gpio_rst, 0); 422 423 msleep(PS8622_POWER_OFF_T17_MS); 424 } 425 426 static int ps8622_attach(struct drm_bridge *bridge, 427 enum drm_bridge_attach_flags flags) 428 { 429 struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge); 430 431 return drm_bridge_attach(ps8622->bridge.encoder, ps8622->panel_bridge, 432 &ps8622->bridge, flags); 433 } 434 435 static const struct drm_bridge_funcs ps8622_bridge_funcs = { 436 .pre_enable = ps8622_pre_enable, 437 .disable = ps8622_disable, 438 .post_disable = ps8622_post_disable, 439 .attach = ps8622_attach, 440 }; 441 442 static const struct of_device_id ps8622_devices[] = { 443 {.compatible = "parade,ps8622",}, 444 {.compatible = "parade,ps8625",}, 445 {} 446 }; 447 MODULE_DEVICE_TABLE(of, ps8622_devices); 448 449 static int ps8622_probe(struct i2c_client *client, 450 const struct i2c_device_id *id) 451 { 452 struct device *dev = &client->dev; 453 struct ps8622_bridge *ps8622; 454 struct drm_bridge *panel_bridge; 455 int ret; 456 457 ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL); 458 if (!ps8622) 459 return -ENOMEM; 460 461 panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0); 462 if (IS_ERR(panel_bridge)) 463 return PTR_ERR(panel_bridge); 464 465 ps8622->panel_bridge = panel_bridge; 466 ps8622->client = client; 467 468 ps8622->v12 = devm_regulator_get(dev, "vdd12"); 469 if (IS_ERR(ps8622->v12)) { 470 dev_info(dev, "no 1.2v regulator found for PS8622\n"); 471 ps8622->v12 = NULL; 472 } 473 474 ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH); 475 if (IS_ERR(ps8622->gpio_slp)) { 476 ret = PTR_ERR(ps8622->gpio_slp); 477 dev_err(dev, "cannot get gpio_slp %d\n", ret); 478 return ret; 479 } 480 481 /* 482 * Assert the reset pin high to avoid the bridge being 483 * initialized prematurely 484 */ 485 ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 486 if (IS_ERR(ps8622->gpio_rst)) { 487 ret = PTR_ERR(ps8622->gpio_rst); 488 dev_err(dev, "cannot get gpio_rst %d\n", ret); 489 return ret; 490 } 491 492 ps8622->max_lane_count = id->driver_data; 493 494 if (of_property_read_u32(dev->of_node, "lane-count", 495 &ps8622->lane_count)) { 496 ps8622->lane_count = ps8622->max_lane_count; 497 } else if (ps8622->lane_count > ps8622->max_lane_count) { 498 dev_info(dev, "lane-count property is too high," 499 "using max_lane_count\n"); 500 ps8622->lane_count = ps8622->max_lane_count; 501 } 502 503 if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) { 504 ps8622->bl = backlight_device_register("ps8622-backlight", 505 dev, ps8622, &ps8622_backlight_ops, 506 NULL); 507 if (IS_ERR(ps8622->bl)) { 508 DRM_ERROR("failed to register backlight\n"); 509 ret = PTR_ERR(ps8622->bl); 510 ps8622->bl = NULL; 511 return ret; 512 } 513 ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS; 514 ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS; 515 } 516 517 ps8622->bridge.funcs = &ps8622_bridge_funcs; 518 ps8622->bridge.type = DRM_MODE_CONNECTOR_LVDS; 519 ps8622->bridge.of_node = dev->of_node; 520 drm_bridge_add(&ps8622->bridge); 521 522 i2c_set_clientdata(client, ps8622); 523 524 return 0; 525 } 526 527 static int ps8622_remove(struct i2c_client *client) 528 { 529 struct ps8622_bridge *ps8622 = i2c_get_clientdata(client); 530 531 backlight_device_unregister(ps8622->bl); 532 drm_bridge_remove(&ps8622->bridge); 533 534 return 0; 535 } 536 537 static const struct i2c_device_id ps8622_i2c_table[] = { 538 /* Device type, max_lane_count */ 539 {"ps8622", 1}, 540 {"ps8625", 2}, 541 {}, 542 }; 543 MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table); 544 545 static struct i2c_driver ps8622_driver = { 546 .id_table = ps8622_i2c_table, 547 .probe = ps8622_probe, 548 .remove = ps8622_remove, 549 .driver = { 550 .name = "ps8622", 551 .of_match_table = ps8622_devices, 552 }, 553 }; 554 module_i2c_driver(ps8622_driver); 555 556 MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>"); 557 MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver"); 558 MODULE_LICENSE("GPL v2"); 559