xref: /openbmc/linux/drivers/usb/cdns3/core.c (revision 8795a739)
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 	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 <pawell@cadence.com>");
650 MODULE_LICENSE("GPL v2");
651 MODULE_DESCRIPTION("Cadence USB3 DRD Controller Driver");
652