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/of.h>
18 #include <linux/platform_device.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/pm_runtime.h>
22
23 #include "core.h"
24 #include "host-export.h"
25 #include "drd.h"
26
27 static int cdns_idle_init(struct cdns *cdns);
28
cdns_role_start(struct cdns * cdns,enum usb_role role)29 static int cdns_role_start(struct cdns *cdns, enum usb_role role)
30 {
31 int ret;
32
33 if (WARN_ON(role > USB_ROLE_DEVICE))
34 return 0;
35
36 mutex_lock(&cdns->mutex);
37 cdns->role = role;
38 mutex_unlock(&cdns->mutex);
39
40 if (!cdns->roles[role])
41 return -ENXIO;
42
43 if (cdns->roles[role]->state == CDNS_ROLE_STATE_ACTIVE)
44 return 0;
45
46 mutex_lock(&cdns->mutex);
47 ret = cdns->roles[role]->start(cdns);
48 if (!ret)
49 cdns->roles[role]->state = CDNS_ROLE_STATE_ACTIVE;
50 mutex_unlock(&cdns->mutex);
51
52 return ret;
53 }
54
cdns_role_stop(struct cdns * cdns)55 static void cdns_role_stop(struct cdns *cdns)
56 {
57 enum usb_role role = cdns->role;
58
59 if (WARN_ON(role > USB_ROLE_DEVICE))
60 return;
61
62 if (cdns->roles[role]->state == CDNS_ROLE_STATE_INACTIVE)
63 return;
64
65 mutex_lock(&cdns->mutex);
66 cdns->roles[role]->stop(cdns);
67 cdns->roles[role]->state = CDNS_ROLE_STATE_INACTIVE;
68 mutex_unlock(&cdns->mutex);
69 }
70
cdns_exit_roles(struct cdns * cdns)71 static void cdns_exit_roles(struct cdns *cdns)
72 {
73 cdns_role_stop(cdns);
74 cdns_drd_exit(cdns);
75 }
76
77 /**
78 * cdns_core_init_role - initialize role of operation
79 * @cdns: Pointer to cdns structure
80 *
81 * Returns 0 on success otherwise negative errno
82 */
cdns_core_init_role(struct cdns * cdns)83 static int cdns_core_init_role(struct cdns *cdns)
84 {
85 struct device *dev = cdns->dev;
86 enum usb_dr_mode best_dr_mode;
87 enum usb_dr_mode dr_mode;
88 int ret;
89
90 dr_mode = usb_get_dr_mode(dev);
91 cdns->role = USB_ROLE_NONE;
92
93 /*
94 * If driver can't read mode by means of usb_get_dr_mode function then
95 * chooses mode according with Kernel configuration. This setting
96 * can be restricted later depending on strap pin configuration.
97 */
98 if (dr_mode == USB_DR_MODE_UNKNOWN) {
99 if (cdns->version == CDNSP_CONTROLLER_V2) {
100 if (IS_ENABLED(CONFIG_USB_CDNSP_HOST) &&
101 IS_ENABLED(CONFIG_USB_CDNSP_GADGET))
102 dr_mode = USB_DR_MODE_OTG;
103 else if (IS_ENABLED(CONFIG_USB_CDNSP_HOST))
104 dr_mode = USB_DR_MODE_HOST;
105 else if (IS_ENABLED(CONFIG_USB_CDNSP_GADGET))
106 dr_mode = USB_DR_MODE_PERIPHERAL;
107 } else {
108 if (IS_ENABLED(CONFIG_USB_CDNS3_HOST) &&
109 IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
110 dr_mode = USB_DR_MODE_OTG;
111 else if (IS_ENABLED(CONFIG_USB_CDNS3_HOST))
112 dr_mode = USB_DR_MODE_HOST;
113 else if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
114 dr_mode = USB_DR_MODE_PERIPHERAL;
115 }
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 = cdns_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 if ((cdns->version == CDNSP_CONTROLLER_V2 &&
141 IS_ENABLED(CONFIG_USB_CDNSP_HOST)) ||
142 (cdns->version < CDNSP_CONTROLLER_V2 &&
143 IS_ENABLED(CONFIG_USB_CDNS3_HOST)))
144 ret = cdns_host_init(cdns);
145 else
146 ret = -ENXIO;
147
148 if (ret) {
149 dev_err(dev, "Host initialization failed with %d\n",
150 ret);
151 goto err;
152 }
153 }
154
155 if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_PERIPHERAL) {
156 if (cdns->gadget_init)
157 ret = cdns->gadget_init(cdns);
158 else
159 ret = -ENXIO;
160
161 if (ret) {
162 dev_err(dev, "Device initialization failed with %d\n",
163 ret);
164 goto err;
165 }
166 }
167
168 cdns->dr_mode = dr_mode;
169
170 ret = cdns_drd_update_mode(cdns);
171 if (ret)
172 goto err;
173
174 /* Initialize idle role to start with */
175 ret = cdns_role_start(cdns, USB_ROLE_NONE);
176 if (ret)
177 goto err;
178
179 switch (cdns->dr_mode) {
180 case USB_DR_MODE_OTG:
181 ret = cdns_hw_role_switch(cdns);
182 if (ret)
183 goto err;
184 break;
185 case USB_DR_MODE_PERIPHERAL:
186 ret = cdns_role_start(cdns, USB_ROLE_DEVICE);
187 if (ret)
188 goto err;
189 break;
190 case USB_DR_MODE_HOST:
191 ret = cdns_role_start(cdns, USB_ROLE_HOST);
192 if (ret)
193 goto err;
194 break;
195 default:
196 ret = -EINVAL;
197 goto err;
198 }
199
200 return 0;
201 err:
202 cdns_exit_roles(cdns);
203 return ret;
204 }
205
206 /**
207 * cdns_hw_role_state_machine - role switch state machine based on hw events.
208 * @cdns: Pointer to controller structure.
209 *
210 * Returns next role to be entered based on hw events.
211 */
cdns_hw_role_state_machine(struct cdns * cdns)212 static enum usb_role cdns_hw_role_state_machine(struct cdns *cdns)
213 {
214 enum usb_role role = USB_ROLE_NONE;
215 int id, vbus;
216
217 if (cdns->dr_mode != USB_DR_MODE_OTG) {
218 if (cdns_is_host(cdns))
219 role = USB_ROLE_HOST;
220 if (cdns_is_device(cdns))
221 role = USB_ROLE_DEVICE;
222
223 return role;
224 }
225
226 id = cdns_get_id(cdns);
227 vbus = cdns_get_vbus(cdns);
228
229 /*
230 * Role change state machine
231 * Inputs: ID, VBUS
232 * Previous state: cdns->role
233 * Next state: role
234 */
235 role = cdns->role;
236
237 switch (role) {
238 case USB_ROLE_NONE:
239 /*
240 * Driver treats USB_ROLE_NONE synonymous to IDLE state from
241 * controller specification.
242 */
243 if (!id)
244 role = USB_ROLE_HOST;
245 else if (vbus)
246 role = USB_ROLE_DEVICE;
247 break;
248 case USB_ROLE_HOST: /* from HOST, we can only change to NONE */
249 if (id)
250 role = USB_ROLE_NONE;
251 break;
252 case USB_ROLE_DEVICE: /* from GADGET, we can only change to NONE*/
253 if (!vbus)
254 role = USB_ROLE_NONE;
255 break;
256 }
257
258 dev_dbg(cdns->dev, "role %d -> %d\n", cdns->role, role);
259
260 return role;
261 }
262
cdns_idle_role_start(struct cdns * cdns)263 static int cdns_idle_role_start(struct cdns *cdns)
264 {
265 return 0;
266 }
267
cdns_idle_role_stop(struct cdns * cdns)268 static void cdns_idle_role_stop(struct cdns *cdns)
269 {
270 /* Program Lane swap and bring PHY out of RESET */
271 phy_reset(cdns->usb3_phy);
272 }
273
cdns_idle_init(struct cdns * cdns)274 static int cdns_idle_init(struct cdns *cdns)
275 {
276 struct cdns_role_driver *rdrv;
277
278 rdrv = devm_kzalloc(cdns->dev, sizeof(*rdrv), GFP_KERNEL);
279 if (!rdrv)
280 return -ENOMEM;
281
282 rdrv->start = cdns_idle_role_start;
283 rdrv->stop = cdns_idle_role_stop;
284 rdrv->state = CDNS_ROLE_STATE_INACTIVE;
285 rdrv->suspend = NULL;
286 rdrv->resume = NULL;
287 rdrv->name = "idle";
288
289 cdns->roles[USB_ROLE_NONE] = rdrv;
290
291 return 0;
292 }
293
294 /**
295 * cdns_hw_role_switch - switch roles based on HW state
296 * @cdns: controller
297 */
cdns_hw_role_switch(struct cdns * cdns)298 int cdns_hw_role_switch(struct cdns *cdns)
299 {
300 enum usb_role real_role, current_role;
301 int ret = 0;
302
303 /* Depends on role switch class */
304 if (cdns->role_sw)
305 return 0;
306
307 pm_runtime_get_sync(cdns->dev);
308
309 current_role = cdns->role;
310 real_role = cdns_hw_role_state_machine(cdns);
311
312 /* Do nothing if nothing changed */
313 if (current_role == real_role)
314 goto exit;
315
316 cdns_role_stop(cdns);
317
318 dev_dbg(cdns->dev, "Switching role %d -> %d", current_role, real_role);
319
320 ret = cdns_role_start(cdns, real_role);
321 if (ret) {
322 /* Back to current role */
323 dev_err(cdns->dev, "set %d has failed, back to %d\n",
324 real_role, current_role);
325 ret = cdns_role_start(cdns, current_role);
326 if (ret)
327 dev_err(cdns->dev, "back to %d failed too\n",
328 current_role);
329 }
330 exit:
331 pm_runtime_put_sync(cdns->dev);
332 return ret;
333 }
334
335 /**
336 * cdns_role_get - get current role of controller.
337 *
338 * @sw: pointer to USB role switch structure
339 *
340 * Returns role
341 */
cdns_role_get(struct usb_role_switch * sw)342 static enum usb_role cdns_role_get(struct usb_role_switch *sw)
343 {
344 struct cdns *cdns = usb_role_switch_get_drvdata(sw);
345
346 return cdns->role;
347 }
348
349 /**
350 * cdns_role_set - set current role of controller.
351 *
352 * @sw: pointer to USB role switch structure
353 * @role: the previous role
354 * Handles below events:
355 * - Role switch for dual-role devices
356 * - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices
357 */
cdns_role_set(struct usb_role_switch * sw,enum usb_role role)358 static int cdns_role_set(struct usb_role_switch *sw, enum usb_role role)
359 {
360 struct cdns *cdns = usb_role_switch_get_drvdata(sw);
361 int ret = 0;
362
363 pm_runtime_get_sync(cdns->dev);
364
365 if (cdns->role == role)
366 goto pm_put;
367
368 if (cdns->dr_mode == USB_DR_MODE_HOST) {
369 switch (role) {
370 case USB_ROLE_NONE:
371 case USB_ROLE_HOST:
372 break;
373 default:
374 goto pm_put;
375 }
376 }
377
378 if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL) {
379 switch (role) {
380 case USB_ROLE_NONE:
381 case USB_ROLE_DEVICE:
382 break;
383 default:
384 goto pm_put;
385 }
386 }
387
388 cdns_role_stop(cdns);
389 ret = cdns_role_start(cdns, role);
390 if (ret)
391 dev_err(cdns->dev, "set role %d has failed\n", role);
392
393 pm_put:
394 pm_runtime_put_sync(cdns->dev);
395 return ret;
396 }
397
398
399 /**
400 * cdns_wakeup_irq - interrupt handler for wakeup events
401 * @irq: irq number for cdns3/cdnsp core device
402 * @data: structure of cdns
403 *
404 * Returns IRQ_HANDLED or IRQ_NONE
405 */
cdns_wakeup_irq(int irq,void * data)406 static irqreturn_t cdns_wakeup_irq(int irq, void *data)
407 {
408 struct cdns *cdns = data;
409
410 if (cdns->in_lpm) {
411 disable_irq_nosync(irq);
412 cdns->wakeup_pending = true;
413 if ((cdns->role == USB_ROLE_HOST) && cdns->host_dev)
414 pm_request_resume(&cdns->host_dev->dev);
415
416 return IRQ_HANDLED;
417 }
418
419 return IRQ_NONE;
420 }
421
422 /**
423 * cdns_init - probe for cdns3/cdnsp core device
424 * @cdns: Pointer to cdns structure.
425 *
426 * Returns 0 on success otherwise negative errno
427 */
cdns_init(struct cdns * cdns)428 int cdns_init(struct cdns *cdns)
429 {
430 struct device *dev = cdns->dev;
431 int ret;
432
433 ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
434 if (ret) {
435 dev_err(dev, "error setting dma mask: %d\n", ret);
436 return ret;
437 }
438
439 mutex_init(&cdns->mutex);
440
441 if (device_property_read_bool(dev, "usb-role-switch")) {
442 struct usb_role_switch_desc sw_desc = { };
443
444 sw_desc.set = cdns_role_set;
445 sw_desc.get = cdns_role_get;
446 sw_desc.allow_userspace_control = true;
447 sw_desc.driver_data = cdns;
448 sw_desc.fwnode = dev->fwnode;
449
450 cdns->role_sw = usb_role_switch_register(dev, &sw_desc);
451 if (IS_ERR(cdns->role_sw)) {
452 dev_warn(dev, "Unable to register Role Switch\n");
453 return PTR_ERR(cdns->role_sw);
454 }
455 }
456
457 if (cdns->wakeup_irq) {
458 ret = devm_request_irq(cdns->dev, cdns->wakeup_irq,
459 cdns_wakeup_irq,
460 IRQF_SHARED,
461 dev_name(cdns->dev), cdns);
462
463 if (ret) {
464 dev_err(cdns->dev, "couldn't register wakeup irq handler\n");
465 goto role_switch_unregister;
466 }
467 }
468
469 ret = cdns_drd_init(cdns);
470 if (ret)
471 goto init_failed;
472
473 ret = cdns_core_init_role(cdns);
474 if (ret)
475 goto init_failed;
476
477 spin_lock_init(&cdns->lock);
478
479 dev_dbg(dev, "Cadence USB3 core: probe succeed\n");
480
481 return 0;
482 init_failed:
483 cdns_drd_exit(cdns);
484 role_switch_unregister:
485 if (cdns->role_sw)
486 usb_role_switch_unregister(cdns->role_sw);
487
488 return ret;
489 }
490 EXPORT_SYMBOL_GPL(cdns_init);
491
492 /**
493 * cdns_remove - unbind drd driver and clean up
494 * @cdns: Pointer to cdns structure.
495 *
496 * Returns 0 on success otherwise negative errno
497 */
cdns_remove(struct cdns * cdns)498 int cdns_remove(struct cdns *cdns)
499 {
500 cdns_exit_roles(cdns);
501 usb_role_switch_unregister(cdns->role_sw);
502
503 return 0;
504 }
505 EXPORT_SYMBOL_GPL(cdns_remove);
506
507 #ifdef CONFIG_PM_SLEEP
cdns_suspend(struct cdns * cdns)508 int cdns_suspend(struct cdns *cdns)
509 {
510 struct device *dev = cdns->dev;
511 unsigned long flags;
512
513 if (pm_runtime_status_suspended(dev))
514 pm_runtime_resume(dev);
515
516 if (cdns->roles[cdns->role]->suspend) {
517 spin_lock_irqsave(&cdns->lock, flags);
518 cdns->roles[cdns->role]->suspend(cdns, false);
519 spin_unlock_irqrestore(&cdns->lock, flags);
520 }
521
522 return 0;
523 }
524 EXPORT_SYMBOL_GPL(cdns_suspend);
525
cdns_resume(struct cdns * cdns)526 int cdns_resume(struct cdns *cdns)
527 {
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 return 0;
560 }
561 EXPORT_SYMBOL_GPL(cdns_resume);
562
cdns_set_active(struct cdns * cdns,u8 set_active)563 void cdns_set_active(struct cdns *cdns, u8 set_active)
564 {
565 struct device *dev = cdns->dev;
566
567 if (set_active) {
568 pm_runtime_disable(dev);
569 pm_runtime_set_active(dev);
570 pm_runtime_enable(dev);
571 }
572
573 return;
574 }
575 EXPORT_SYMBOL_GPL(cdns_set_active);
576 #endif /* CONFIG_PM_SLEEP */
577
578 MODULE_AUTHOR("Peter Chen <peter.chen@nxp.com>");
579 MODULE_AUTHOR("Pawel Laszczak <pawell@cadence.com>");
580 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
581 MODULE_DESCRIPTION("Cadence USBSS and USBSSP DRD Driver");
582 MODULE_LICENSE("GPL");
583
