1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Cadence USBSS and USBSSP DRD Driver. 4 * 5 * Copyright (C) 2018-2019 Cadence. 6 * Copyright (C) 2017-2018 NXP 7 * Copyright (C) 2019 Texas Instruments 8 * 9 * Author: Peter Chen <peter.chen@nxp.com> 10 * Pawel Laszczak <pawell@cadence.com> 11 * Roger Quadros <rogerq@ti.com> 12 */ 13 14 #include <linux/dma-mapping.h> 15 #include <linux/module.h> 16 #include <linux/kernel.h> 17 #include <linux/platform_device.h> 18 #include <linux/interrupt.h> 19 #include <linux/io.h> 20 #include <linux/pm_runtime.h> 21 22 #include "core.h" 23 #include "host-export.h" 24 #include "drd.h" 25 26 static int cdns_idle_init(struct cdns *cdns); 27 28 static int cdns_role_start(struct cdns *cdns, enum usb_role role) 29 { 30 int ret; 31 32 if (WARN_ON(role > USB_ROLE_DEVICE)) 33 return 0; 34 35 mutex_lock(&cdns->mutex); 36 cdns->role = role; 37 mutex_unlock(&cdns->mutex); 38 39 if (!cdns->roles[role]) 40 return -ENXIO; 41 42 if (cdns->roles[role]->state == CDNS_ROLE_STATE_ACTIVE) 43 return 0; 44 45 mutex_lock(&cdns->mutex); 46 ret = cdns->roles[role]->start(cdns); 47 if (!ret) 48 cdns->roles[role]->state = CDNS_ROLE_STATE_ACTIVE; 49 mutex_unlock(&cdns->mutex); 50 51 return ret; 52 } 53 54 static void cdns_role_stop(struct cdns *cdns) 55 { 56 enum usb_role role = cdns->role; 57 58 if (WARN_ON(role > USB_ROLE_DEVICE)) 59 return; 60 61 if (cdns->roles[role]->state == CDNS_ROLE_STATE_INACTIVE) 62 return; 63 64 mutex_lock(&cdns->mutex); 65 cdns->roles[role]->stop(cdns); 66 cdns->roles[role]->state = CDNS_ROLE_STATE_INACTIVE; 67 mutex_unlock(&cdns->mutex); 68 } 69 70 static void cdns_exit_roles(struct cdns *cdns) 71 { 72 cdns_role_stop(cdns); 73 cdns_drd_exit(cdns); 74 } 75 76 /** 77 * cdns_core_init_role - initialize role of operation 78 * @cdns: Pointer to cdns structure 79 * 80 * Returns 0 on success otherwise negative errno 81 */ 82 static int cdns_core_init_role(struct cdns *cdns) 83 { 84 struct device *dev = cdns->dev; 85 enum usb_dr_mode best_dr_mode; 86 enum usb_dr_mode dr_mode; 87 int ret; 88 89 dr_mode = usb_get_dr_mode(dev); 90 cdns->role = USB_ROLE_NONE; 91 92 /* 93 * If driver can't read mode by means of usb_get_dr_mode function then 94 * chooses mode according with Kernel configuration. This setting 95 * can be restricted later depending on strap pin configuration. 96 */ 97 if (dr_mode == USB_DR_MODE_UNKNOWN) { 98 if (cdns->version == CDNSP_CONTROLLER_V2) { 99 if (IS_ENABLED(CONFIG_USB_CDNSP_HOST) && 100 IS_ENABLED(CONFIG_USB_CDNSP_GADGET)) 101 dr_mode = USB_DR_MODE_OTG; 102 else if (IS_ENABLED(CONFIG_USB_CDNSP_HOST)) 103 dr_mode = USB_DR_MODE_HOST; 104 else if (IS_ENABLED(CONFIG_USB_CDNSP_GADGET)) 105 dr_mode = USB_DR_MODE_PERIPHERAL; 106 } else { 107 if (IS_ENABLED(CONFIG_USB_CDNS3_HOST) && 108 IS_ENABLED(CONFIG_USB_CDNS3_GADGET)) 109 dr_mode = USB_DR_MODE_OTG; 110 else if (IS_ENABLED(CONFIG_USB_CDNS3_HOST)) 111 dr_mode = USB_DR_MODE_HOST; 112 else if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET)) 113 dr_mode = USB_DR_MODE_PERIPHERAL; 114 } 115 } 116 117 /* 118 * At this point cdns->dr_mode contains strap configuration. 119 * Driver try update this setting considering kernel configuration 120 */ 121 best_dr_mode = cdns->dr_mode; 122 123 ret = cdns_idle_init(cdns); 124 if (ret) 125 return ret; 126 127 if (dr_mode == USB_DR_MODE_OTG) { 128 best_dr_mode = cdns->dr_mode; 129 } else if (cdns->dr_mode == USB_DR_MODE_OTG) { 130 best_dr_mode = dr_mode; 131 } else if (cdns->dr_mode != dr_mode) { 132 dev_err(dev, "Incorrect DRD configuration\n"); 133 return -EINVAL; 134 } 135 136 dr_mode = best_dr_mode; 137 138 if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_HOST) { 139 if ((cdns->version == CDNSP_CONTROLLER_V2 && 140 IS_ENABLED(CONFIG_USB_CDNSP_HOST)) || 141 (cdns->version < CDNSP_CONTROLLER_V2 && 142 IS_ENABLED(CONFIG_USB_CDNS3_HOST))) 143 ret = cdns_host_init(cdns); 144 else 145 ret = -ENXIO; 146 147 if (ret) { 148 dev_err(dev, "Host initialization failed with %d\n", 149 ret); 150 goto err; 151 } 152 } 153 154 if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_PERIPHERAL) { 155 if (cdns->gadget_init) 156 ret = cdns->gadget_init(cdns); 157 else 158 ret = -ENXIO; 159 160 if (ret) { 161 dev_err(dev, "Device initialization failed with %d\n", 162 ret); 163 goto err; 164 } 165 } 166 167 cdns->dr_mode = dr_mode; 168 169 ret = cdns_drd_update_mode(cdns); 170 if (ret) 171 goto err; 172 173 /* Initialize idle role to start with */ 174 ret = cdns_role_start(cdns, USB_ROLE_NONE); 175 if (ret) 176 goto err; 177 178 switch (cdns->dr_mode) { 179 case USB_DR_MODE_OTG: 180 ret = cdns_hw_role_switch(cdns); 181 if (ret) 182 goto err; 183 break; 184 case USB_DR_MODE_PERIPHERAL: 185 ret = cdns_role_start(cdns, USB_ROLE_DEVICE); 186 if (ret) 187 goto err; 188 break; 189 case USB_DR_MODE_HOST: 190 ret = cdns_role_start(cdns, USB_ROLE_HOST); 191 if (ret) 192 goto err; 193 break; 194 default: 195 ret = -EINVAL; 196 goto err; 197 } 198 199 return 0; 200 err: 201 cdns_exit_roles(cdns); 202 return ret; 203 } 204 205 /** 206 * cdns_hw_role_state_machine - role switch state machine based on hw events. 207 * @cdns: Pointer to controller structure. 208 * 209 * Returns next role to be entered based on hw events. 210 */ 211 static enum usb_role cdns_hw_role_state_machine(struct cdns *cdns) 212 { 213 enum usb_role role = USB_ROLE_NONE; 214 int id, vbus; 215 216 if (cdns->dr_mode != USB_DR_MODE_OTG) { 217 if (cdns_is_host(cdns)) 218 role = USB_ROLE_HOST; 219 if (cdns_is_device(cdns)) 220 role = USB_ROLE_DEVICE; 221 222 return role; 223 } 224 225 id = cdns_get_id(cdns); 226 vbus = cdns_get_vbus(cdns); 227 228 /* 229 * Role change state machine 230 * Inputs: ID, VBUS 231 * Previous state: cdns->role 232 * Next state: role 233 */ 234 role = cdns->role; 235 236 switch (role) { 237 case USB_ROLE_NONE: 238 /* 239 * Driver treats USB_ROLE_NONE synonymous to IDLE state from 240 * controller specification. 241 */ 242 if (!id) 243 role = USB_ROLE_HOST; 244 else if (vbus) 245 role = USB_ROLE_DEVICE; 246 break; 247 case USB_ROLE_HOST: /* from HOST, we can only change to NONE */ 248 if (id) 249 role = USB_ROLE_NONE; 250 break; 251 case USB_ROLE_DEVICE: /* from GADGET, we can only change to NONE*/ 252 if (!vbus) 253 role = USB_ROLE_NONE; 254 break; 255 } 256 257 dev_dbg(cdns->dev, "role %d -> %d\n", cdns->role, role); 258 259 return role; 260 } 261 262 static int cdns_idle_role_start(struct cdns *cdns) 263 { 264 return 0; 265 } 266 267 static void cdns_idle_role_stop(struct cdns *cdns) 268 { 269 /* Program Lane swap and bring PHY out of RESET */ 270 phy_reset(cdns->usb3_phy); 271 } 272 273 static int cdns_idle_init(struct cdns *cdns) 274 { 275 struct cdns_role_driver *rdrv; 276 277 rdrv = devm_kzalloc(cdns->dev, sizeof(*rdrv), GFP_KERNEL); 278 if (!rdrv) 279 return -ENOMEM; 280 281 rdrv->start = cdns_idle_role_start; 282 rdrv->stop = cdns_idle_role_stop; 283 rdrv->state = CDNS_ROLE_STATE_INACTIVE; 284 rdrv->suspend = NULL; 285 rdrv->resume = NULL; 286 rdrv->name = "idle"; 287 288 cdns->roles[USB_ROLE_NONE] = rdrv; 289 290 return 0; 291 } 292 293 /** 294 * cdns_hw_role_switch - switch roles based on HW state 295 * @cdns: controller 296 */ 297 int cdns_hw_role_switch(struct cdns *cdns) 298 { 299 enum usb_role real_role, current_role; 300 int ret = 0; 301 302 /* Depends on role switch class */ 303 if (cdns->role_sw) 304 return 0; 305 306 pm_runtime_get_sync(cdns->dev); 307 308 current_role = cdns->role; 309 real_role = cdns_hw_role_state_machine(cdns); 310 311 /* Do nothing if nothing changed */ 312 if (current_role == real_role) 313 goto exit; 314 315 cdns_role_stop(cdns); 316 317 dev_dbg(cdns->dev, "Switching role %d -> %d", current_role, real_role); 318 319 ret = cdns_role_start(cdns, real_role); 320 if (ret) { 321 /* Back to current role */ 322 dev_err(cdns->dev, "set %d has failed, back to %d\n", 323 real_role, current_role); 324 ret = cdns_role_start(cdns, current_role); 325 if (ret) 326 dev_err(cdns->dev, "back to %d failed too\n", 327 current_role); 328 } 329 exit: 330 pm_runtime_put_sync(cdns->dev); 331 return ret; 332 } 333 334 /** 335 * cdsn3_role_get - get current role of controller. 336 * 337 * @sw: pointer to USB role switch structure 338 * 339 * Returns role 340 */ 341 static enum usb_role cdns_role_get(struct usb_role_switch *sw) 342 { 343 struct cdns *cdns = usb_role_switch_get_drvdata(sw); 344 345 return cdns->role; 346 } 347 348 /** 349 * cdns_role_set - set current role of controller. 350 * 351 * @sw: pointer to USB role switch structure 352 * @role: the previous role 353 * Handles below events: 354 * - Role switch for dual-role devices 355 * - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices 356 */ 357 static int cdns_role_set(struct usb_role_switch *sw, enum usb_role role) 358 { 359 struct cdns *cdns = usb_role_switch_get_drvdata(sw); 360 int ret = 0; 361 362 pm_runtime_get_sync(cdns->dev); 363 364 if (cdns->role == role) 365 goto pm_put; 366 367 if (cdns->dr_mode == USB_DR_MODE_HOST) { 368 switch (role) { 369 case USB_ROLE_NONE: 370 case USB_ROLE_HOST: 371 break; 372 default: 373 goto pm_put; 374 } 375 } 376 377 if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL) { 378 switch (role) { 379 case USB_ROLE_NONE: 380 case USB_ROLE_DEVICE: 381 break; 382 default: 383 goto pm_put; 384 } 385 } 386 387 cdns_role_stop(cdns); 388 ret = cdns_role_start(cdns, role); 389 if (ret) 390 dev_err(cdns->dev, "set role %d has failed\n", role); 391 392 pm_put: 393 pm_runtime_put_sync(cdns->dev); 394 return ret; 395 } 396 397 398 /** 399 * cdns_wakeup_irq - interrupt handler for wakeup events 400 * @irq: irq number for cdns3/cdnsp core device 401 * @data: structure of cdns 402 * 403 * Returns IRQ_HANDLED or IRQ_NONE 404 */ 405 static irqreturn_t cdns_wakeup_irq(int irq, void *data) 406 { 407 struct cdns *cdns = data; 408 409 if (cdns->in_lpm) { 410 disable_irq_nosync(irq); 411 cdns->wakeup_pending = true; 412 if ((cdns->role == USB_ROLE_HOST) && cdns->host_dev) 413 pm_request_resume(&cdns->host_dev->dev); 414 415 return IRQ_HANDLED; 416 } 417 418 return IRQ_NONE; 419 } 420 421 /** 422 * cdns_probe - probe for cdns3/cdnsp core device 423 * @cdns: Pointer to cdns structure. 424 * 425 * Returns 0 on success otherwise negative errno 426 */ 427 int cdns_init(struct cdns *cdns) 428 { 429 struct device *dev = cdns->dev; 430 int ret; 431 432 ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32)); 433 if (ret) { 434 dev_err(dev, "error setting dma mask: %d\n", ret); 435 return ret; 436 } 437 438 mutex_init(&cdns->mutex); 439 440 if (device_property_read_bool(dev, "usb-role-switch")) { 441 struct usb_role_switch_desc sw_desc = { }; 442 443 sw_desc.set = cdns_role_set; 444 sw_desc.get = cdns_role_get; 445 sw_desc.allow_userspace_control = true; 446 sw_desc.driver_data = cdns; 447 sw_desc.fwnode = dev->fwnode; 448 449 cdns->role_sw = usb_role_switch_register(dev, &sw_desc); 450 if (IS_ERR(cdns->role_sw)) { 451 dev_warn(dev, "Unable to register Role Switch\n"); 452 return PTR_ERR(cdns->role_sw); 453 } 454 } 455 456 if (cdns->wakeup_irq) { 457 ret = devm_request_irq(cdns->dev, cdns->wakeup_irq, 458 cdns_wakeup_irq, 459 IRQF_SHARED, 460 dev_name(cdns->dev), cdns); 461 462 if (ret) { 463 dev_err(cdns->dev, "couldn't register wakeup irq handler\n"); 464 goto role_switch_unregister; 465 } 466 } 467 468 ret = cdns_drd_init(cdns); 469 if (ret) 470 goto init_failed; 471 472 ret = cdns_core_init_role(cdns); 473 if (ret) 474 goto init_failed; 475 476 spin_lock_init(&cdns->lock); 477 478 dev_dbg(dev, "Cadence USB3 core: probe succeed\n"); 479 480 return 0; 481 init_failed: 482 cdns_drd_exit(cdns); 483 role_switch_unregister: 484 if (cdns->role_sw) 485 usb_role_switch_unregister(cdns->role_sw); 486 487 return ret; 488 } 489 EXPORT_SYMBOL_GPL(cdns_init); 490 491 /** 492 * cdns_remove - unbind drd driver and clean up 493 * @cdns: Pointer to cdns structure. 494 * 495 * Returns 0 on success otherwise negative errno 496 */ 497 int cdns_remove(struct cdns *cdns) 498 { 499 cdns_exit_roles(cdns); 500 usb_role_switch_unregister(cdns->role_sw); 501 502 return 0; 503 } 504 EXPORT_SYMBOL_GPL(cdns_remove); 505 506 #ifdef CONFIG_PM_SLEEP 507 int cdns_suspend(struct cdns *cdns) 508 { 509 struct device *dev = cdns->dev; 510 unsigned long flags; 511 512 if (pm_runtime_status_suspended(dev)) 513 pm_runtime_resume(dev); 514 515 if (cdns->roles[cdns->role]->suspend) { 516 spin_lock_irqsave(&cdns->lock, flags); 517 cdns->roles[cdns->role]->suspend(cdns, false); 518 spin_unlock_irqrestore(&cdns->lock, flags); 519 } 520 521 return 0; 522 } 523 EXPORT_SYMBOL_GPL(cdns_suspend); 524 525 int cdns_resume(struct cdns *cdns, u8 set_active) 526 { 527 struct device *dev = cdns->dev; 528 enum usb_role real_role; 529 bool role_changed = false; 530 int ret = 0; 531 532 if (cdns_power_is_lost(cdns)) { 533 if (cdns->role_sw) { 534 cdns->role = cdns_role_get(cdns->role_sw); 535 } else { 536 real_role = cdns_hw_role_state_machine(cdns); 537 if (real_role != cdns->role) { 538 ret = cdns_hw_role_switch(cdns); 539 if (ret) 540 return ret; 541 role_changed = true; 542 } 543 } 544 545 if (!role_changed) { 546 if (cdns->role == USB_ROLE_HOST) 547 ret = cdns_drd_host_on(cdns); 548 else if (cdns->role == USB_ROLE_DEVICE) 549 ret = cdns_drd_gadget_on(cdns); 550 551 if (ret) 552 return ret; 553 } 554 } 555 556 if (cdns->roles[cdns->role]->resume) 557 cdns->roles[cdns->role]->resume(cdns, cdns_power_is_lost(cdns)); 558 559 if (set_active) { 560 pm_runtime_disable(dev); 561 pm_runtime_set_active(dev); 562 pm_runtime_enable(dev); 563 } 564 565 return 0; 566 } 567 EXPORT_SYMBOL_GPL(cdns_resume); 568 #endif /* CONFIG_PM_SLEEP */ 569 570 MODULE_AUTHOR("Peter Chen <peter.chen@nxp.com>"); 571 MODULE_AUTHOR("Pawel Laszczak <pawell@cadence.com>"); 572 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>"); 573 MODULE_DESCRIPTION("Cadence USBSS and USBSSP DRD Driver"); 574 MODULE_LICENSE("GPL"); 575