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
cdns_role_start(struct cdns * cdns,enum usb_role role)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
cdns_role_stop(struct cdns * cdns)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
cdns_exit_roles(struct cdns * cdns)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 */
cdns_core_init_role(struct cdns * cdns)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 */
cdns_hw_role_state_machine(struct cdns * cdns)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
cdns_idle_role_start(struct cdns * cdns)262 static int cdns_idle_role_start(struct cdns *cdns)
263 {
264 return 0;
265 }
266
cdns_idle_role_stop(struct cdns * cdns)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
cdns_idle_init(struct cdns * cdns)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 */
cdns_hw_role_switch(struct cdns * cdns)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 */
cdns_role_get(struct usb_role_switch * sw)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 */
cdns_role_set(struct usb_role_switch * sw,enum usb_role role)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 */
cdns_wakeup_irq(int irq,void * data)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 */
cdns_init(struct cdns * cdns)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 */
cdns_remove(struct cdns * cdns)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
cdns_suspend(struct cdns * cdns)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
cdns_resume(struct cdns * cdns,u8 set_active)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