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 <[email protected]>
  10  *         Pawel Laszczak <[email protected]>
  11  *         Roger Quadros <[email protected]>
  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         if (cdns->dr_mode != USB_DR_MODE_OTG) {
 164                 ret = cdns3_hw_role_switch(cdns);
 165                 if (ret)
 166                         goto err;
 167         }
 168
 169         return ret;
 170 err:
 171         cdns3_exit_roles(cdns);
 172         return ret;
 173 }
 174
 175 /**
 176  * cdsn3_hw_role_state_machine  - role switch state machine based on hw events.
 177  * @cdns: Pointer to controller structure.
 178  *
 179  * Returns next role to be entered based on hw events.
 180  */
 181 static enum usb_role cdsn3_hw_role_state_machine(struct cdns3 *cdns)
 182 {
 183         enum usb_role role;
 184         int id, vbus;
 185
 186         if (cdns->dr_mode != USB_DR_MODE_OTG)
 187                 goto not_otg;
 188
 189         id = cdns3_get_id(cdns);
 190         vbus = cdns3_get_vbus(cdns);
 191
 192         /*
 193          * Role change state machine
 194          * Inputs: ID, VBUS
 195          * Previous state: cdns->role
 196          * Next state: role
 197          */
 198         role = cdns->role;
 199
 200         switch (role) {
 201         case USB_ROLE_NONE:
 202                 /*
 203                  * Driver treats USB_ROLE_NONE synonymous to IDLE state from
 204                  * controller specification.
 205                  */
 206                 if (!id)
 207                         role = USB_ROLE_HOST;
 208                 else if (vbus)
 209                         role = USB_ROLE_DEVICE;
 210                 break;
 211         case USB_ROLE_HOST: /* from HOST, we can only change to NONE */
 212                 if (id)
 213                         role = USB_ROLE_NONE;
 214                 break;
 215         case USB_ROLE_DEVICE: /* from GADGET, we can only change to NONE*/
 216                 if (!vbus)
 217                         role = USB_ROLE_NONE;
 218                 break;
 219         }
 220
 221         dev_dbg(cdns->dev, "role %d -> %d\n", cdns->role, role);
 222
 223         return role;
 224
 225 not_otg:
 226         if (cdns3_is_host(cdns))
 227                 role = USB_ROLE_HOST;
 228         if (cdns3_is_device(cdns))
 229                 role = USB_ROLE_DEVICE;
 230
 231         return role;
 232 }
 233
 234 static int cdns3_idle_role_start(struct cdns3 *cdns)
 235 {
 236         return 0;
 237 }
 238
 239 static void cdns3_idle_role_stop(struct cdns3 *cdns)
 240 {
 241         /* Program Lane swap and bring PHY out of RESET */
 242         phy_reset(cdns->usb3_phy);
 243 }
 244
 245 static int cdns3_idle_init(struct cdns3 *cdns)
 246 {
 247         struct cdns3_role_driver *rdrv;
 248
 249         rdrv = devm_kzalloc(cdns->dev, sizeof(*rdrv), GFP_KERNEL);
 250         if (!rdrv)
 251                 return -ENOMEM;
 252
 253         rdrv->start = cdns3_idle_role_start;
 254         rdrv->stop = cdns3_idle_role_stop;
 255         rdrv->state = CDNS3_ROLE_STATE_INACTIVE;
 256         rdrv->suspend = NULL;
 257         rdrv->resume = NULL;
 258         rdrv->name = "idle";
 259
 260         cdns->roles[USB_ROLE_NONE] = rdrv;
 261
 262         return 0;
 263 }
 264
 265 /**
 266  * cdns3_hw_role_switch - switch roles based on HW state
 267  * @cdns3: controller
 268  */
 269 int cdns3_hw_role_switch(struct cdns3 *cdns)
 270 {
 271         enum usb_role real_role, current_role;
 272         int ret = 0;
 273
 274         /* Do nothing if role based on syfs. */
 275         if (cdns->role_override)
 276                 return 0;
 277
 278         pm_runtime_get_sync(cdns->dev);
 279
 280         current_role = cdns->role;
 281         real_role = cdsn3_hw_role_state_machine(cdns);
 282
 283         /* Do nothing if nothing changed */
 284         if (current_role == real_role)
 285                 goto exit;
 286
 287         cdns3_role_stop(cdns);
 288
 289         dev_dbg(cdns->dev, "Switching role %d -> %d", current_role, real_role);
 290
 291         ret = cdns3_role_start(cdns, real_role);
 292         if (ret) {
 293                 /* Back to current role */
 294                 dev_err(cdns->dev, "set %d has failed, back to %d\n",
 295                         real_role, current_role);
 296                 ret = cdns3_role_start(cdns, current_role);
 297                 if (ret)
 298                         dev_err(cdns->dev, "back to %d failed too\n",
 299                                 current_role);
 300         }
 301 exit:
 302         pm_runtime_put_sync(cdns->dev);
 303         return ret;
 304 }
 305
 306 /**
 307  * cdsn3_role_get - get current role of controller.
 308  *
 309  * @dev: Pointer to device structure
 310  *
 311  * Returns role
 312  */
 313 static enum usb_role cdns3_role_get(struct device *dev)
 314 {
 315         struct cdns3 *cdns = dev_get_drvdata(dev);
 316
 317         return cdns->role;
 318 }
 319
 320 /**
 321  * cdns3_role_set - set current role of controller.
 322  *
 323  * @dev: pointer to device object
 324  * @role - the previous role
 325  * Handles below events:
 326  * - Role switch for dual-role devices
 327  * - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices
 328  */
 329 static int cdns3_role_set(struct device *dev, enum usb_role role)
 330 {
 331         struct cdns3 *cdns = dev_get_drvdata(dev);
 332         int ret = 0;
 333
 334         pm_runtime_get_sync(cdns->dev);
 335
 336         /*
 337          * FIXME: switch role framework should be extended to meet
 338          * requirements. Driver assumes that role can be controlled
 339          * by SW or HW. Temporary workaround is to use USB_ROLE_NONE to
 340          * switch from SW to HW control.
 341          *
 342          * For dr_mode == USB_DR_MODE_OTG:
 343          *      if user sets USB_ROLE_HOST or USB_ROLE_DEVICE then driver
 344          *      sets role_override flag and forces that role.
 345          *      if user sets USB_ROLE_NONE, driver clears role_override and lets
 346          *      HW state machine take over.
 347          *
 348          * For dr_mode != USB_DR_MODE_OTG:
 349          *      Assumptions:
 350          *      1. Restricted user control between NONE and dr_mode.
 351          *      2. Driver doesn't need to rely on role_override flag.
 352          *      3. Driver needs to ensure that HW state machine is never called
 353          *         if dr_mode != USB_DR_MODE_OTG.
 354          */
 355         if (role == USB_ROLE_NONE)
 356                 cdns->role_override = 0;
 357         else
 358                 cdns->role_override = 1;
 359
 360         /*
 361          * HW state might have changed so driver need to trigger
 362          * HW state machine if dr_mode == USB_DR_MODE_OTG.
 363          */
 364         if (!cdns->role_override && cdns->dr_mode == USB_DR_MODE_OTG) {
 365                 cdns3_hw_role_switch(cdns);
 366                 goto pm_put;
 367         }
 368
 369         if (cdns->role == role)
 370                 goto pm_put;
 371
 372         if (cdns->dr_mode == USB_DR_MODE_HOST) {
 373                 switch (role) {
 374                 case USB_ROLE_NONE:
 375                 case USB_ROLE_HOST:
 376                         break;
 377                 default:
 378                         ret = -EPERM;
 379                         goto pm_put;
 380                 }
 381         }
 382
 383         if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL) {
 384                 switch (role) {
 385                 case USB_ROLE_NONE:
 386                 case USB_ROLE_DEVICE:
 387                         break;
 388                 default:
 389                         ret = -EPERM;
 390                         goto pm_put;
 391                 }
 392         }
 393
 394         cdns3_role_stop(cdns);
 395         ret = cdns3_role_start(cdns, role);
 396         if (ret) {
 397                 dev_err(cdns->dev, "set role %d has failed\n", role);
 398                 ret = -EPERM;
 399         }
 400
 401 pm_put:
 402         pm_runtime_put_sync(cdns->dev);
 403         return ret;
 404 }
 405
 406 static const struct usb_role_switch_desc cdns3_switch_desc = {
 407         .set = cdns3_role_set,
 408         .get = cdns3_role_get,
 409         .allow_userspace_control = true,
 410 };
 411
 412 /**
 413  * cdns3_probe - probe for cdns3 core device
 414  * @pdev: Pointer to cdns3 core platform device
 415  *
 416  * Returns 0 on success otherwise negative errno
 417  */
 418 static int cdns3_probe(struct platform_device *pdev)
 419 {
 420         struct device *dev = &pdev->dev;
 421         struct resource *res;
 422         struct cdns3 *cdns;
 423         void __iomem *regs;
 424         int ret;
 425
 426         ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
 427         if (ret) {
 428                 dev_err(dev, "error setting dma mask: %d\n", ret);
 429                 return -ENODEV;
 430         }
 431
 432         cdns = devm_kzalloc(dev, sizeof(*cdns), GFP_KERNEL);
 433         if (!cdns)
 434                 return -ENOMEM;
 435
 436         cdns->dev = dev;
 437
 438         platform_set_drvdata(pdev, cdns);
 439
 440         res = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "host");
 441         if (!res) {
 442                 dev_err(dev, "missing host IRQ\n");
 443                 return -ENODEV;
 444         }
 445
 446         cdns->xhci_res[0] = *res;
 447
 448         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "xhci");
 449         if (!res) {
 450                 dev_err(dev, "couldn't get xhci resource\n");
 451                 return -ENXIO;
 452         }
 453
 454         cdns->xhci_res[1] = *res;
 455
 456         cdns->dev_irq = platform_get_irq_byname(pdev, "peripheral");
 457         if (cdns->dev_irq == -EPROBE_DEFER)
 458                 return cdns->dev_irq;
 459
 460         if (cdns->dev_irq < 0)
 461                 dev_err(dev, "couldn't get peripheral irq\n");
 462
 463         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dev");
 464         regs = devm_ioremap_resource(dev, res);
 465         if (IS_ERR(regs))
 466                 return PTR_ERR(regs);
 467         cdns->dev_regs  = regs;
 468
 469         cdns->otg_irq = platform_get_irq_byname(pdev, "otg");
 470         if (cdns->otg_irq == -EPROBE_DEFER)
 471                 return cdns->otg_irq;
 472
 473         if (cdns->otg_irq < 0) {
 474                 dev_err(dev, "couldn't get otg irq\n");
 475                 return cdns->otg_irq;
 476         }
 477
 478         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "otg");
 479         if (!res) {
 480                 dev_err(dev, "couldn't get otg resource\n");
 481                 return -ENXIO;
 482         }
 483
 484         cdns->otg_res = *res;
 485
 486         mutex_init(&cdns->mutex);
 487
 488         cdns->usb2_phy = devm_phy_optional_get(dev, "cdns3,usb2-phy");
 489         if (IS_ERR(cdns->usb2_phy))
 490                 return PTR_ERR(cdns->usb2_phy);
 491
 492         ret = phy_init(cdns->usb2_phy);
 493         if (ret)
 494                 return ret;
 495
 496         cdns->usb3_phy = devm_phy_optional_get(dev, "cdns3,usb3-phy");
 497         if (IS_ERR(cdns->usb3_phy))
 498                 return PTR_ERR(cdns->usb3_phy);
 499
 500         ret = phy_init(cdns->usb3_phy);
 501         if (ret)
 502                 goto err1;
 503
 504         ret = phy_power_on(cdns->usb2_phy);
 505         if (ret)
 506                 goto err2;
 507
 508         ret = phy_power_on(cdns->usb3_phy);
 509         if (ret)
 510                 goto err3;
 511
 512         cdns->role_sw = usb_role_switch_register(dev, &cdns3_switch_desc);
 513         if (IS_ERR(cdns->role_sw)) {
 514                 ret = PTR_ERR(cdns->role_sw);
 515                 dev_warn(dev, "Unable to register Role Switch\n");
 516                 goto err4;
 517         }
 518
 519         ret = cdns3_drd_init(cdns);
 520         if (ret)
 521                 goto err5;
 522
 523         ret = cdns3_core_init_role(cdns);
 524         if (ret)
 525                 goto err5;
 526
 527         device_set_wakeup_capable(dev, true);
 528         pm_runtime_set_active(dev);
 529         pm_runtime_enable(dev);
 530
 531         /*
 532          * The controller needs less time between bus and controller suspend,
 533          * and we also needs a small delay to avoid frequently entering low
 534          * power mode.
 535          */
 536         pm_runtime_set_autosuspend_delay(dev, 20);
 537         pm_runtime_mark_last_busy(dev);
 538         pm_runtime_use_autosuspend(dev);
 539         dev_dbg(dev, "Cadence USB3 core: probe succeed\n");
 540
 541         return 0;
 542 err5:
 543         cdns3_drd_exit(cdns);
 544         usb_role_switch_unregister(cdns->role_sw);
 545 err4:
 546         phy_power_off(cdns->usb3_phy);
 547
 548 err3:
 549         phy_power_off(cdns->usb2_phy);
 550 err2:
 551         phy_exit(cdns->usb3_phy);
 552 err1:
 553         phy_exit(cdns->usb2_phy);
 554
 555         return ret;
 556 }
 557
 558 /**
 559  * cdns3_remove - unbind drd driver and clean up
 560  * @pdev: Pointer to Linux platform device
 561  *
 562  * Returns 0 on success otherwise negative errno
 563  */
 564 static int cdns3_remove(struct platform_device *pdev)
 565 {
 566         struct cdns3 *cdns = platform_get_drvdata(pdev);
 567
 568         pm_runtime_get_sync(&pdev->dev);
 569         pm_runtime_disable(&pdev->dev);
 570         pm_runtime_put_noidle(&pdev->dev);
 571         cdns3_exit_roles(cdns);
 572         usb_role_switch_unregister(cdns->role_sw);
 573         phy_power_off(cdns->usb2_phy);
 574         phy_power_off(cdns->usb3_phy);
 575         phy_exit(cdns->usb2_phy);
 576         phy_exit(cdns->usb3_phy);
 577         return 0;
 578 }
 579
 580 #ifdef CONFIG_PM_SLEEP
 581
 582 static int cdns3_suspend(struct device *dev)
 583 {
 584         struct cdns3 *cdns = dev_get_drvdata(dev);
 585         unsigned long flags;
 586
 587         if (cdns->role == USB_ROLE_HOST)
 588                 return 0;
 589
 590         if (pm_runtime_status_suspended(dev))
 591                 pm_runtime_resume(dev);
 592
 593         if (cdns->roles[cdns->role]->suspend) {
 594                 spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
 595                 cdns->roles[cdns->role]->suspend(cdns, false);
 596                 spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
 597         }
 598
 599         return 0;
 600 }
 601
 602 static int cdns3_resume(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 (cdns->roles[cdns->role]->resume) {
 611                 spin_lock_irqsave(&cdns->gadget_dev->lock, flags);
 612                 cdns->roles[cdns->role]->resume(cdns, false);
 613                 spin_unlock_irqrestore(&cdns->gadget_dev->lock, flags);
 614         }
 615
 616         pm_runtime_disable(dev);
 617         pm_runtime_set_active(dev);
 618         pm_runtime_enable(dev);
 619
 620         return 0;
 621 }
 622 #endif
 623
 624 static const struct dev_pm_ops cdns3_pm_ops = {
 625         SET_SYSTEM_SLEEP_PM_OPS(cdns3_suspend, cdns3_resume)
 626 };
 627
 628 #ifdef CONFIG_OF
 629 static const struct of_device_id of_cdns3_match[] = {
 630         { .compatible = "cdns,usb3" },
 631         { },
 632 };
 633 MODULE_DEVICE_TABLE(of, of_cdns3_match);
 634 #endif
 635
 636 static struct platform_driver cdns3_driver = {
 637         .probe          = cdns3_probe,
 638         .remove         = cdns3_remove,
 639         .driver         = {
 640                 .name   = "cdns-usb3",
 641                 .of_match_table = of_match_ptr(of_cdns3_match),
 642                 .pm     = &cdns3_pm_ops,
 643         },
 644 };
 645
 646 module_platform_driver(cdns3_driver);
 647
 648 MODULE_ALIAS("platform:cdns3");
 649 MODULE_AUTHOR("Pawel Laszczak <[email protected]>");
 650 MODULE_LICENSE("GPL v2");
 651 MODULE_DESCRIPTION("Cadence USB3 DRD Controller Driver");