drivers/usb/cdns3/core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Cadence USBSS 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 "gadget.h"
  23 #include "core.h"
  24 #include "host-export.h"
  25 #include "gadget-export.h"
  26 #include "drd.h"
  27
  28 static int cdns3_idle_init(struct cdns3 *cdns);
  29
  30 static inline
  31 struct cdns3_role_driver *cdns3_get_current_role_driver(struct cdns3 *cdns)
  32 {
  33         WARN_ON(!cdns->roles[cdns->role]);
  34         return cdns->roles[cdns->role];
  35 }
  36
  37 static int cdns3_role_start(struct cdns3 *cdns, enum usb_role role)
  38 {
  39         int ret;
  40
  41         if (WARN_ON(role > USB_ROLE_DEVICE))
  42                 return 0;
  43
  44         mutex_lock(&cdns->mutex);
  45         cdns->role = role;
  46         mutex_unlock(&cdns->mutex);
  47
  48         if (!cdns->roles[role])
  49                 return -ENXIO;
  50
  51         if (cdns->roles[role]->state == CDNS3_ROLE_STATE_ACTIVE)
  52                 return 0;
  53
  54         mutex_lock(&cdns->mutex);
  55         ret = cdns->roles[role]->start(cdns);
  56         if (!ret)
  57                 cdns->roles[role]->state = CDNS3_ROLE_STATE_ACTIVE;
  58         mutex_unlock(&cdns->mutex);
  59
  60         return ret;
  61 }
  62
  63 static void cdns3_role_stop(struct cdns3 *cdns)
  64 {
  65         enum usb_role role = cdns->role;
  66
  67         if (WARN_ON(role > USB_ROLE_DEVICE))
  68                 return;
  69
  70         if (cdns->roles[role]->state == CDNS3_ROLE_STATE_INACTIVE)
  71                 return;
  72
  73         mutex_lock(&cdns->mutex);
  74         cdns->roles[role]->stop(cdns);
  75         cdns->roles[role]->state = CDNS3_ROLE_STATE_INACTIVE;
  76         mutex_unlock(&cdns->mutex);
  77 }
  78
  79 static void cdns3_exit_roles(struct cdns3 *cdns)
  80 {
  81         cdns3_role_stop(cdns);
  82         cdns3_drd_exit(cdns);
  83 }
  84
  85 static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns);
  86
  87 /**
  88  * cdns3_core_init_role - initialize role of operation
  89  * @cdns: Pointer to cdns3 structure
  90  *
  91  * Returns 0 on success otherwise negative errno
  92  */
  93 static int cdns3_core_init_role(struct cdns3 *cdns)
  94 {
  95         struct device *dev = cdns->dev;
  96         enum usb_dr_mode best_dr_mode;
  97         enum usb_dr_mode dr_mode;
  98         int ret = 0;
  99
 100         dr_mode = usb_get_dr_mode(dev);
 101         cdns->role = USB_ROLE_NONE;
 102
 103         /*
 104          * If driver can't read mode by means of usb_get_dr_mode function then
 105          * chooses mode according with Kernel configuration. This setting
 106          * can be restricted later depending on strap pin configuration.
 107          */
 108         if (dr_mode == USB_DR_MODE_UNKNOWN) {
 109                 if (IS_ENABLED(CONFIG_USB_CDNS3_HOST) &&
 110                     IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
 111                         dr_mode = USB_DR_MODE_OTG;
 112                 else if (IS_ENABLED(CONFIG_USB_CDNS3_HOST))
 113                         dr_mode = USB_DR_MODE_HOST;
 114                 else if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
 115                         dr_mode = USB_DR_MODE_PERIPHERAL;
 116         }
 117
 118         /*
 119          * At this point cdns->dr_mode contains strap configuration.
 120          * Driver try update this setting considering kernel configuration
 121          */
 122         best_dr_mode = cdns->dr_mode;
 123
 124         ret = cdns3_idle_init(cdns);
 125         if (ret)
 126                 return ret;
 127
 128         if (dr_mode == USB_DR_MODE_OTG) {
 129                 best_dr_mode = cdns->dr_mode;
 130         } else if (cdns->dr_mode == USB_DR_MODE_OTG) {
 131                 best_dr_mode = dr_mode;
 132         } else if (cdns->dr_mode != dr_mode) {
 133                 dev_err(dev, "Incorrect DRD configuration\n");
 134                 return -EINVAL;
 135         }
 136
 137         dr_mode = best_dr_mode;
 138
 139         if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_HOST) {
 140                 ret = cdns3_host_init(cdns);
 141                 if (ret) {
 142                         dev_err(dev, "Host initialization failed with %d\n",
 143                                 ret);
 144                         goto err;
 145                 }
 146         }
 147
 148         if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_PERIPHERAL) {
 149                 ret = cdns3_gadget_init(cdns);
 150                 if (ret) {
 151                         dev_err(dev, "Device initialization failed with %d\n",
 152                                 ret);
 153                         goto err;
 154                 }
 155         }
 156
 157         cdns->dr_mode = dr_mode;
 158
 159         ret = cdns3_drd_update_mode(cdns);
 160         if (ret)
 161                 goto err;
 162
 163         /* Initialize idle role to start with */
 164         ret = cdns3_role_start(cdns, USB_ROLE_NONE);
 165         if (ret)
 166                 goto err;
 167
 168         switch (cdns->dr_mode) {
 169         case USB_DR_MODE_OTG:
 170                 ret = cdns3_hw_role_switch(cdns);
 171                 if (ret)
 172                         goto err;
 173                 break;
 174         case USB_DR_MODE_PERIPHERAL:
 175                 ret = cdns3_role_start(cdns, USB_ROLE_DEVICE);
 176                 if (ret)
 177                         goto err;
 178                 break;
 179         case USB_DR_MODE_HOST:
 180                 ret = cdns3_role_start(cdns, USB_ROLE_HOST);
 181                 if (ret)
 182                         goto err;
 183                 break;
 184         default:
 185                 ret = -EINVAL;
 186                 goto err;
 187         }
 188
 189         return ret;
 190 err:
 191         cdns3_exit_roles(cdns);
 192         return ret;
 193 }
 194
 195 /**
 196  * cdsn3_hw_role_state_machine  - role switch state machine based on hw events.
 197  * @cdns: Pointer to controller structure.
 198  *
 199  * Returns next role to be entered based on hw events.
 200  */
 201 static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns)
 202 {
 203         enum usb_role role;
 204         int id, vbus;
 205
 206         if (cdns->dr_mode != USB_DR_MODE_OTG)
 207                 goto not_otg;
 208
 209         id = cdns3_get_id(cdns);
 210         vbus = cdns3_get_vbus(cdns);
 211
 212         /*
 213          * Role change state machine
 214          * Inputs: ID, VBUS
 215          * Previous state: cdns->role
 216          * Next state: role
 217          */
 218         role = cdns->role;
 219
 220         switch (role) {
 221         case USB_ROLE_NONE:
 222                 /*
 223                  * Driver treats USB_ROLE_NONE synonymous to IDLE state from
 224                  * controller specification.
 225                  */
 226                 if (!id)
 227                         role = USB_ROLE_HOST;
 228                 else if (vbus)
 229                         role = USB_ROLE_DEVICE;
 230                 break;
 231         case USB_ROLE_HOST: /* from HOST, we can only change to NONE */
 232                 if (id)
 233                         role = USB_ROLE_NONE;
 234                 break;
 235         case USB_ROLE_DEVICE: /* from GADGET, we can only change to NONE*/
 236                 if (!vbus)
 237                         role = USB_ROLE_NONE;
 238                 break;
 239         }
 240
 241         dev_dbg(cdns->dev, "role %d -> %d\n", cdns->role, role);
 242
 243         return role;
 244
 245 not_otg:
 246         if (cdns3_is_host(cdns))
 247                 role = USB_ROLE_HOST;
 248         if (cdns3_is_device(cdns))
 249                 role = USB_ROLE_DEVICE;
 250
 251         return role;
 252 }
 253
 254 static int cdns3_idle_role_start(struct cdns3 *cdns)
 255 {
 256         return 0;
 257 }
 258
 259 static void cdns3_idle_role_stop(struct cdns3 *cdns)
 260 {
 261         /* Program Lane swap and bring PHY out of RESET */
 262         phy_reset(cdns->usb3_phy);
 263 }
 264
 265 static int cdns3_idle_init(struct cdns3 *cdns)
 266 {
 267         struct cdns3_role_driver *rdrv;
 268
 269         rdrv = devm_kzalloc(cdns->dev, sizeof(*rdrv), GFP_KERNEL);
 270         if (!rdrv)
 271                 return -ENOMEM;
 272
 273         rdrv->start = cdns3_idle_role_start;
 274         rdrv->stop = cdns3_idle_role_stop;
 275         rdrv->state = CDNS3_ROLE_STATE_INACTIVE;
 276         rdrv->suspend = NULL;
 277         rdrv->resume = NULL;
 278         rdrv->name = "idle";
 279
 280         cdns->roles[USB_ROLE_NONE] = rdrv;
 281
 282         return 0;
 283 }
 284
 285 /**
 286  * cdns3_hw_role_switch - switch roles based on HW state
 287  * @cdns3: controller
 288  */
 289 int cdns3_hw_role_switch(struct cdns3 *cdns)
 290 {
 291         enum usb_role real_role, current_role;
 292         int ret = 0;
 293
 294         /* Do nothing if role based on syfs. */
 295         if (cdns->role_override)
 296                 return 0;
 297
 298         pm_runtime_get_sync(cdns->dev);
 299
 300         current_role = cdns->role;
 301         real_role = cdsn3_hw_role_state_machine(cdns);
 302
 303         /* Do nothing if nothing changed */
 304         if (current_role == real_role)
 305                 goto exit;
 306
 307         cdns3_role_stop(cdns);
 308
 309         dev_dbg(cdns->dev, "Switching role %d -> %d", current_role, real_role);
 310
 311         ret = cdns3_role_start(cdns, real_role);
 312         if (ret) {
 313                 /* Back to current role */
 314                 dev_err(cdns->dev, "set %d has failed, back to %d\n",
 315                         real_role, current_role);
 316                 ret = cdns3_role_start(cdns, current_role);
 317                 if (ret)
 318                         dev_err(cdns->dev, "back to %d failed too\n",
 319                                 current_role);
 320         }
 321 exit:
 322         pm_runtime_put_sync(cdns->dev);
 323         return ret;
 324 }
 325
 326 /**
 327  * cdsn3_role_get - get current role of controller.
 328  *
 329  * @dev: Pointer to device structure
 330  *
 331  * Returns role
 332  */
 333 static enum usb_role cdns3_role_get(struct device *dev)
 334 {
 335         struct cdns3 *cdns = dev_get_drvdata(dev);
 336
 337         return cdns->role;
 338 }
 339
 340 /**
 341  * cdns3_role_set - set current role of controller.
 342  *
 343  * @dev: pointer to device object
 344  * @role - the previous role
 345  * Handles below events:
 346  * - Role switch for dual-role devices
 347  * - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices
 348  */
 349 static int cdns3_role_set(struct device *dev, enum usb_role role)
 350 {
 351         struct cdns3 *cdns = dev_get_drvdata(dev);
 352         int ret = 0;
 353
 354         pm_runtime_get_sync(cdns->dev);
 355
 356         /*
 357          * FIXME: switch role framework should be extended to meet
 358          * requirements. Driver assumes that role can be controlled
 359          * by SW or HW. Temporary workaround is to use USB_ROLE_NONE to
 360          * switch from SW to HW control.
 361          *
 362          * For dr_mode == USB_DR_MODE_OTG:
 363          *      if user sets USB_ROLE_HOST or USB_ROLE_DEVICE then driver
 364          *      sets role_override flag and forces that role.
 365          *      if user sets USB_ROLE_NONE, driver clears role_override and lets
 366          *      HW state machine take over.
 367          *
 368          * For dr_mode != USB_DR_MODE_OTG:
 369          *      Assumptions:
 370          *      1. Restricted user control between NONE and dr_mode.
 371          *      2. Driver doesn't need to rely on role_override flag.
 372          *      3. Driver needs to ensure that HW state machine is never called
 373          *         if dr_mode != USB_DR_MODE_OTG.
 374          */
 375         if (role == USB_ROLE_NONE)
 376                 cdns->role_override = 0;
 377         else
 378                 cdns->role_override = 1;
 379
 380         /*
 381          * HW state might have changed so driver need to trigger
 382          * HW state machine if dr_mode == USB_DR_MODE_OTG.
 383          */
 384         if (!cdns->role_override && cdns->dr_mode == USB_DR_MODE_OTG) {
 385                 cdns3_hw_role_switch(cdns);
 386                 goto pm_put;
 387         }
 388
 389         if (cdns->role == role)
 390                 goto pm_put;
 391
 392         if (cdns->dr_mode == USB_DR_MODE_HOST) {
 393                 switch (role) {
 394                 case USB_ROLE_NONE:
 395                 case USB_ROLE_HOST:
 396                         break;
 397                 default:
 398                         ret = -EPERM;
 399                         goto pm_put;
 400                 }
 401         }
 402
 403         if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL) {
 404                 switch (role) {
 405                 case USB_ROLE_NONE:
 406                 case USB_ROLE_DEVICE:
 407                         break;
 408                 default:
 409                         ret = -EPERM;
 410                         goto pm_put;
 411                 }
 412         }
 413
 414         cdns3_role_stop(cdns);
 415         ret = cdns3_role_start(cdns, role);
 416         if (ret) {
 417                 dev_err(cdns->dev, "set role %d has failed\n", role);
 418                 ret = -EPERM;
 419         }
 420
 421 pm_put:
 422         pm_runtime_put_sync(cdns->dev);
 423         return ret;
 424 }
 425
 426 static const struct usb_role_switch_desc cdns3_switch_desc = {
 427         .set = cdns3_role_set,
 428         .get = cdns3_role_get,
 429         .allow_userspace_control = true,
 430 };
 431
 432 /**
 433  * cdns3_probe - probe for cdns3 core device
 434  * @pdev: Pointer to cdns3 core platform device
 435  *
 436  * Returns 0 on success otherwise negative errno
 437  */
 438 static int cdns3_probe(struct platform_device *pdev)
 439 {
 440         struct device *dev = &pdev->dev;
 441         struct resource *res;
 442         struct cdns3 *cdns;
 443         void __iomem *regs;
 444         int ret;
 445
 446         ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
 447         if (ret) {
 448                 dev_err(dev, "error setting dma mask: %d\n", ret);
 449                 return -ENODEV;
 450         }
 451
 452         cdns = devm_kzalloc(dev, sizeof(*cdns), GFP_KERNEL);
 453         if (!cdns)
 454                 return -ENOMEM;
 455
 456         cdns->dev = dev;
 457
 458         platform_set_drvdata(pdev, cdns);
 459
 460         res = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "host");
 461         if (!res) {
 462                 dev_err(dev, "missing host IRQ\n");
 463                 return -ENODEV;
 464         }
 465
 466         cdns->xhci_res[0] = *res;
 467
 468         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "xhci");
 469         if (!res) {
 470                 dev_err(dev, "couldn't get xhci resource\n");
 471                 return -ENXIO;
 472         }
 473
 474         cdns->xhci_res[1] = *res;
 475
 476         cdns->dev_irq = platform_get_irq_byname(pdev, "peripheral");
 477         if (cdns->dev_irq == -EPROBE_DEFER)
 478                 return cdns->dev_irq;
 479
 480         if (cdns->dev_irq < 0)
 481                 dev_err(dev, "couldn't get peripheral irq\n");
 482
 483         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dev");
 484         regs = devm_ioremap_resource(dev, res);
 485         if (IS_ERR(regs))
 486                 return PTR_ERR(regs);
 487         cdns->dev_regs  = regs;
 488
 489         cdns->otg_irq = platform_get_irq_byname(pdev, "otg");
 490         if (cdns->otg_irq == -EPROBE_DEFER)
 491                 return cdns->otg_irq;
 492
 493         if (cdns->otg_irq < 0) {
 494                 dev_err(dev, "couldn't get otg irq\n");
 495                 return cdns->otg_irq;
 496         }
 497
 498         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "otg");
 499         if (!res) {
 500                 dev_err(dev, "couldn't get otg resource\n");
 501                 return -ENXIO;
 502         }
 503
 504         cdns->otg_res = *res;
 505
 506         mutex_init(&cdns->mutex);
 507
 508         cdns->usb2_phy = devm_phy_optional_get(dev, "cdns3,usb2-phy");
 509         if (IS_ERR(cdns->usb2_phy))
 510                 return PTR_ERR(cdns->usb2_phy);
 511
 512         ret = phy_init(cdns->usb2_phy);
 513         if (ret)
 514                 return ret;
 515
 516         cdns->usb3_phy = devm_phy_optional_get(dev, "cdns3,usb3-phy");
 517         if (IS_ERR(cdns->usb3_phy))
 518                 return PTR_ERR(cdns->usb3_phy);
 519
 520         ret = phy_init(cdns->usb3_phy);
 521         if (ret)
 522                 goto err1;
 523
 524         ret = phy_power_on(cdns->usb2_phy);
 525         if (ret)
 526                 goto err2;
 527
 528         ret = phy_power_on(cdns->usb3_phy);
 529         if (ret)
 530                 goto err3;
 531
 532         cdns->role_sw = usb_role_switch_register(dev, &cdns3_switch_desc);
 533         if (IS_ERR(cdns->role_sw)) {
 534                 ret = PTR_ERR(cdns->role_sw);
 535                 dev_warn(dev, "Unable to register Role Switch\n");
 536                 goto err4;
 537         }
 538
 539         ret = cdns3_drd_init(cdns);
 540         if (ret)
 541                 goto err5;
 542
 543         ret = cdns3_core_init_role(cdns);
 544         if (ret)
 545                 goto err5;
 546
 547         device_set_wakeup_capable(dev, true);
 548         pm_runtime_set_active(dev);
 549         pm_runtime_enable(dev);
 550
 551         /*
 552          * The controller needs less time between bus and controller suspend,
 553          * and we also needs a small delay to avoid frequently entering low
 554          * power mode.
 555          */
 556         pm_runtime_set_autosuspend_delay(dev, 20);
 557         pm_runtime_mark_last_busy(dev);
 558         pm_runtime_use_autosuspend(dev);
 559         dev_dbg(dev, "Cadence USB3 core: probe succeed\n");
 560
 561         return 0;
 562 err5:
 563         cdns3_drd_exit(cdns);
 564         usb_role_switch_unregister(cdns->role_sw);
 565 err4:
 566         phy_power_off(cdns->usb3_phy);
 567
 568 err3:
 569         phy_power_off(cdns->usb2_phy);
 570 err2:
 571         phy_exit(cdns->usb3_phy);
 572 err1:
 573         phy_exit(cdns->usb2_phy);
 574
 575         return ret;
 576 }
 577
 578 /**
 579  * cdns3_remove - unbind drd driver and clean up
 580  * @pdev: Pointer to Linux platform device
 581  *
 582  * Returns 0 on success otherwise negative errno
 583  */
 584 static int cdns3_remove(struct platform_device *pdev)
 585 {
 586         struct cdns3 *cdns = platform_get_drvdata(pdev);
 587
 588         pm_runtime_get_sync(&pdev->dev);
 589         pm_runtime_disable(&pdev->dev);
 590         pm_runtime_put_noidle(&pdev->dev);
 591         cdns3_exit_roles(cdns);
 592         usb_role_switch_unregister(cdns->role_sw);
 593         phy_power_off(cdns->usb2_phy);
 594         phy_power_off(cdns->usb3_phy);
 595         phy_exit(cdns->usb2_phy);
 596         phy_exit(cdns->usb3_phy);
 597         return 0;
 598 }
 599
 600 #ifdef CONFIG_PM_SLEEP
 601
 602 static int cdns3_suspend(struct device *dev)
 603 {
 604         struct cdns3 *cdns = dev_get_drvdata(dev);
 605         unsigned long flags;
 606
 607         if (cdns->role == USB_ROLE_HOST)
 608                 return 0;
 609
 610         if (pm_runtime_status_suspended(dev))
 611                 pm_runtime_resume(dev);
 612
 613         if (cdns->roles[cdns->role]->suspend) {
 614                 spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
 615                 cdns->roles[cdns->role]->suspend(cdns, false);
 616                 spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
 617         }
 618
 619         return 0;
 620 }
 621
 622 static int cdns3_resume(struct device *dev)
 623 {
 624         struct cdns3 *cdns = dev_get_drvdata(dev);
 625         unsigned long flags;
 626
 627         if (cdns->role == USB_ROLE_HOST)
 628                 return 0;
 629
 630         if (cdns->roles[cdns->role]->resume) {
 631                 spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
 632                 cdns->roles[cdns->role]->resume(cdns, false);
 633                 spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
 634         }
 635
 636         pm_runtime_disable(dev);
 637         pm_runtime_set_active(dev);
 638         pm_runtime_enable(dev);
 639
 640         return 0;
 641 }
 642 #endif
 643
 644 static const struct dev_pm_ops cdns3_pm_ops = {
 645         SET_SYSTEM_SLEEP_PM_OPS(cdns3_suspend, cdns3_resume)
 646 };
 647
 648 #ifdef CONFIG_OF
 649 static const struct of_device_id of_cdns3_match[] = {
 650         { .compatible = "cdns,usb3" },
 651         { },
 652 };
 653 MODULE_DEVICE_TABLE(of, of_cdns3_match);
 654 #endif
 655
 656 static struct platform_driver cdns3_driver = {
 657         .probe          = cdns3_probe,
 658         .remove         = cdns3_remove,
 659         .driver         = {
 660                 .name   = "cdns-usb3",
 661                 .of_match_table = of_match_ptr(of_cdns3_match),
 662                 .pm     = &cdns3_pm_ops,
 663         },
 664 };
 665
 666 module_platform_driver(cdns3_driver);
 667
 668 MODULE_ALIAS("platform:cdns3");
 669 MODULE_AUTHOR("Pawel Laszczak <pawell@cadence.com>");
 670 MODULE_LICENSE("GPL v2");
 671 MODULE_DESCRIPTION("Cadence USB3 DRD Controller Driver");