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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
28static int cdns3_idle_init(struct cdns3 *cdns);
29
30static inline
31struct 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
37static 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
63static 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
79static void cdns3_exit_roles(struct cdns3 *cdns)
80{
81 cdns3_role_stop(cdns);
82 cdns3_drd_exit(cdns);
83}
84
85static 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 */
93static 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;
190err:
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 */
201static 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
245not_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
254static int cdns3_idle_role_start(struct cdns3 *cdns)
255{
256 return 0;
257}
258
259static 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
265static 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 */
289int 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 }
321exit:
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 */
333static 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 */
349static 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
421pm_put:
422 pm_runtime_put_sync(cdns->dev);
423 return ret;
424}
425
426static 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 */
438static 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;
562err5:
563 cdns3_drd_exit(cdns);
564 usb_role_switch_unregister(cdns->role_sw);
565err4:
566 phy_power_off(cdns->usb3_phy);
567
568err3:
569 phy_power_off(cdns->usb2_phy);
570err2:
571 phy_exit(cdns->usb3_phy);
572err1:
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 */
584static 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
602static 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
622static 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
644static const struct dev_pm_ops cdns3_pm_ops = {
645 SET_SYSTEM_SLEEP_PM_OPS(cdns3_suspend, cdns3_resume)
646};
647
648#ifdef CONFIG_OF
649static const struct of_device_id of_cdns3_match[] = {
650 { .compatible = "cdns,usb3" },
651 { },
652};
653MODULE_DEVICE_TABLE(of, of_cdns3_match);
654#endif
655
656static 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
666module_platform_driver(cdns3_driver);
667
668MODULE_ALIAS("platform:cdns3");
669MODULE_AUTHOR("Pawel Laszczak <pawell@cadence.com>");
670MODULE_LICENSE("GPL v2");
671MODULE_DESCRIPTION("Cadence USB3 DRD Controller Driver");