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