xref: /openbmc/linux/drivers/usb/phy/phy-mv-usb.c (revision bbb774d9) 
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2011 Marvell International Ltd. All rights reserved.
4  * Author: Chao Xie <chao.xie@marvell.com>
5  *	   Neil Zhang <zhangwm@marvell.com>
6  */
7 
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/io.h>
11 #include <linux/iopoll.h>
12 #include <linux/uaccess.h>
13 #include <linux/device.h>
14 #include <linux/proc_fs.h>
15 #include <linux/clk.h>
16 #include <linux/workqueue.h>
17 #include <linux/platform_device.h>
18 
19 #include <linux/usb.h>
20 #include <linux/usb/ch9.h>
21 #include <linux/usb/otg.h>
22 #include <linux/usb/gadget.h>
23 #include <linux/usb/hcd.h>
24 #include <linux/platform_data/mv_usb.h>
25 
26 #include "phy-mv-usb.h"
27 
28 #define	DRIVER_DESC	"Marvell USB OTG transceiver driver"
29 
30 MODULE_DESCRIPTION(DRIVER_DESC);
31 MODULE_LICENSE("GPL");
32 
33 static const char driver_name[] = "mv-otg";
34 
35 static char *state_string[] = {
36 	"undefined",
37 	"b_idle",
38 	"b_srp_init",
39 	"b_peripheral",
40 	"b_wait_acon",
41 	"b_host",
42 	"a_idle",
43 	"a_wait_vrise",
44 	"a_wait_bcon",
45 	"a_host",
46 	"a_suspend",
47 	"a_peripheral",
48 	"a_wait_vfall",
49 	"a_vbus_err"
50 };
51 
52 static int mv_otg_set_vbus(struct usb_otg *otg, bool on)
53 {
54 	struct mv_otg *mvotg = container_of(otg->usb_phy, struct mv_otg, phy);
55 	if (mvotg->pdata->set_vbus == NULL)
56 		return -ENODEV;
57 
58 	return mvotg->pdata->set_vbus(on);
59 }
60 
61 static int mv_otg_set_host(struct usb_otg *otg,
62 			   struct usb_bus *host)
63 {
64 	otg->host = host;
65 
66 	return 0;
67 }
68 
69 static int mv_otg_set_peripheral(struct usb_otg *otg,
70 				 struct usb_gadget *gadget)
71 {
72 	otg->gadget = gadget;
73 
74 	return 0;
75 }
76 
77 static void mv_otg_run_state_machine(struct mv_otg *mvotg,
78 				     unsigned long delay)
79 {
80 	dev_dbg(&mvotg->pdev->dev, "transceiver is updated\n");
81 	if (!mvotg->qwork)
82 		return;
83 
84 	queue_delayed_work(mvotg->qwork, &mvotg->work, delay);
85 }
86 
87 static void mv_otg_timer_await_bcon(struct timer_list *t)
88 {
89 	struct mv_otg *mvotg = from_timer(mvotg, t,
90 					  otg_ctrl.timer[A_WAIT_BCON_TIMER]);
91 
92 	mvotg->otg_ctrl.a_wait_bcon_timeout = 1;
93 
94 	dev_info(&mvotg->pdev->dev, "B Device No Response!\n");
95 
96 	if (spin_trylock(&mvotg->wq_lock)) {
97 		mv_otg_run_state_machine(mvotg, 0);
98 		spin_unlock(&mvotg->wq_lock);
99 	}
100 }
101 
102 static int mv_otg_cancel_timer(struct mv_otg *mvotg, unsigned int id)
103 {
104 	struct timer_list *timer;
105 
106 	if (id >= OTG_TIMER_NUM)
107 		return -EINVAL;
108 
109 	timer = &mvotg->otg_ctrl.timer[id];
110 
111 	if (timer_pending(timer))
112 		del_timer(timer);
113 
114 	return 0;
115 }
116 
117 static int mv_otg_set_timer(struct mv_otg *mvotg, unsigned int id,
118 			    unsigned long interval)
119 {
120 	struct timer_list *timer;
121 
122 	if (id >= OTG_TIMER_NUM)
123 		return -EINVAL;
124 
125 	timer = &mvotg->otg_ctrl.timer[id];
126 	if (timer_pending(timer)) {
127 		dev_err(&mvotg->pdev->dev, "Timer%d is already running\n", id);
128 		return -EBUSY;
129 	}
130 
131 	timer->expires = jiffies + interval;
132 	add_timer(timer);
133 
134 	return 0;
135 }
136 
137 static int mv_otg_reset(struct mv_otg *mvotg)
138 {
139 	u32 tmp;
140 	int ret;
141 
142 	/* Stop the controller */
143 	tmp = readl(&mvotg->op_regs->usbcmd);
144 	tmp &= ~USBCMD_RUN_STOP;
145 	writel(tmp, &mvotg->op_regs->usbcmd);
146 
147 	/* Reset the controller to get default values */
148 	writel(USBCMD_CTRL_RESET, &mvotg->op_regs->usbcmd);
149 
150 	ret = readl_poll_timeout_atomic(&mvotg->op_regs->usbcmd, tmp,
151 				(tmp & USBCMD_CTRL_RESET), 10, 10000);
152 	if (ret < 0) {
153 		dev_err(&mvotg->pdev->dev,
154 			"Wait for RESET completed TIMEOUT\n");
155 		return ret;
156 	}
157 
158 	writel(0x0, &mvotg->op_regs->usbintr);
159 	tmp = readl(&mvotg->op_regs->usbsts);
160 	writel(tmp, &mvotg->op_regs->usbsts);
161 
162 	return 0;
163 }
164 
165 static void mv_otg_init_irq(struct mv_otg *mvotg)
166 {
167 	u32 otgsc;
168 
169 	mvotg->irq_en = OTGSC_INTR_A_SESSION_VALID
170 	    | OTGSC_INTR_A_VBUS_VALID;
171 	mvotg->irq_status = OTGSC_INTSTS_A_SESSION_VALID
172 	    | OTGSC_INTSTS_A_VBUS_VALID;
173 
174 	if (mvotg->pdata->vbus == NULL) {
175 		mvotg->irq_en |= OTGSC_INTR_B_SESSION_VALID
176 		    | OTGSC_INTR_B_SESSION_END;
177 		mvotg->irq_status |= OTGSC_INTSTS_B_SESSION_VALID
178 		    | OTGSC_INTSTS_B_SESSION_END;
179 	}
180 
181 	if (mvotg->pdata->id == NULL) {
182 		mvotg->irq_en |= OTGSC_INTR_USB_ID;
183 		mvotg->irq_status |= OTGSC_INTSTS_USB_ID;
184 	}
185 
186 	otgsc = readl(&mvotg->op_regs->otgsc);
187 	otgsc |= mvotg->irq_en;
188 	writel(otgsc, &mvotg->op_regs->otgsc);
189 }
190 
191 static void mv_otg_start_host(struct mv_otg *mvotg, int on)
192 {
193 #ifdef CONFIG_USB
194 	struct usb_otg *otg = mvotg->phy.otg;
195 	struct usb_hcd *hcd;
196 
197 	if (!otg->host)
198 		return;
199 
200 	dev_info(&mvotg->pdev->dev, "%s host\n", on ? "start" : "stop");
201 
202 	hcd = bus_to_hcd(otg->host);
203 
204 	if (on) {
205 		usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
206 		device_wakeup_enable(hcd->self.controller);
207 	} else {
208 		usb_remove_hcd(hcd);
209 	}
210 #endif /* CONFIG_USB */
211 }
212 
213 static void mv_otg_start_periphrals(struct mv_otg *mvotg, int on)
214 {
215 	struct usb_otg *otg = mvotg->phy.otg;
216 
217 	if (!otg->gadget)
218 		return;
219 
220 	dev_info(mvotg->phy.dev, "gadget %s\n", on ? "on" : "off");
221 
222 	if (on)
223 		usb_gadget_vbus_connect(otg->gadget);
224 	else
225 		usb_gadget_vbus_disconnect(otg->gadget);
226 }
227 
228 static void otg_clock_enable(struct mv_otg *mvotg)
229 {
230 	clk_prepare_enable(mvotg->clk);
231 }
232 
233 static void otg_clock_disable(struct mv_otg *mvotg)
234 {
235 	clk_disable_unprepare(mvotg->clk);
236 }
237 
238 static int mv_otg_enable_internal(struct mv_otg *mvotg)
239 {
240 	int retval = 0;
241 
242 	if (mvotg->active)
243 		return 0;
244 
245 	dev_dbg(&mvotg->pdev->dev, "otg enabled\n");
246 
247 	otg_clock_enable(mvotg);
248 	if (mvotg->pdata->phy_init) {
249 		retval = mvotg->pdata->phy_init(mvotg->phy_regs);
250 		if (retval) {
251 			dev_err(&mvotg->pdev->dev,
252 				"init phy error %d\n", retval);
253 			otg_clock_disable(mvotg);
254 			return retval;
255 		}
256 	}
257 	mvotg->active = 1;
258 
259 	return 0;
260 
261 }
262 
263 static int mv_otg_enable(struct mv_otg *mvotg)
264 {
265 	if (mvotg->clock_gating)
266 		return mv_otg_enable_internal(mvotg);
267 
268 	return 0;
269 }
270 
271 static void mv_otg_disable_internal(struct mv_otg *mvotg)
272 {
273 	if (mvotg->active) {
274 		dev_dbg(&mvotg->pdev->dev, "otg disabled\n");
275 		if (mvotg->pdata->phy_deinit)
276 			mvotg->pdata->phy_deinit(mvotg->phy_regs);
277 		otg_clock_disable(mvotg);
278 		mvotg->active = 0;
279 	}
280 }
281 
282 static void mv_otg_disable(struct mv_otg *mvotg)
283 {
284 	if (mvotg->clock_gating)
285 		mv_otg_disable_internal(mvotg);
286 }
287 
288 static void mv_otg_update_inputs(struct mv_otg *mvotg)
289 {
290 	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
291 	u32 otgsc;
292 
293 	otgsc = readl(&mvotg->op_regs->otgsc);
294 
295 	if (mvotg->pdata->vbus) {
296 		if (mvotg->pdata->vbus->poll() == VBUS_HIGH) {
297 			otg_ctrl->b_sess_vld = 1;
298 			otg_ctrl->b_sess_end = 0;
299 		} else {
300 			otg_ctrl->b_sess_vld = 0;
301 			otg_ctrl->b_sess_end = 1;
302 		}
303 	} else {
304 		otg_ctrl->b_sess_vld = !!(otgsc & OTGSC_STS_B_SESSION_VALID);
305 		otg_ctrl->b_sess_end = !!(otgsc & OTGSC_STS_B_SESSION_END);
306 	}
307 
308 	if (mvotg->pdata->id)
309 		otg_ctrl->id = !!mvotg->pdata->id->poll();
310 	else
311 		otg_ctrl->id = !!(otgsc & OTGSC_STS_USB_ID);
312 
313 	if (mvotg->pdata->otg_force_a_bus_req && !otg_ctrl->id)
314 		otg_ctrl->a_bus_req = 1;
315 
316 	otg_ctrl->a_sess_vld = !!(otgsc & OTGSC_STS_A_SESSION_VALID);
317 	otg_ctrl->a_vbus_vld = !!(otgsc & OTGSC_STS_A_VBUS_VALID);
318 
319 	dev_dbg(&mvotg->pdev->dev, "%s: ", __func__);
320 	dev_dbg(&mvotg->pdev->dev, "id %d\n", otg_ctrl->id);
321 	dev_dbg(&mvotg->pdev->dev, "b_sess_vld %d\n", otg_ctrl->b_sess_vld);
322 	dev_dbg(&mvotg->pdev->dev, "b_sess_end %d\n", otg_ctrl->b_sess_end);
323 	dev_dbg(&mvotg->pdev->dev, "a_vbus_vld %d\n", otg_ctrl->a_vbus_vld);
324 	dev_dbg(&mvotg->pdev->dev, "a_sess_vld %d\n", otg_ctrl->a_sess_vld);
325 }
326 
327 static void mv_otg_update_state(struct mv_otg *mvotg)
328 {
329 	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
330 	int old_state = mvotg->phy.otg->state;
331 
332 	switch (old_state) {
333 	case OTG_STATE_UNDEFINED:
334 		mvotg->phy.otg->state = OTG_STATE_B_IDLE;
335 		fallthrough;
336 	case OTG_STATE_B_IDLE:
337 		if (otg_ctrl->id == 0)
338 			mvotg->phy.otg->state = OTG_STATE_A_IDLE;
339 		else if (otg_ctrl->b_sess_vld)
340 			mvotg->phy.otg->state = OTG_STATE_B_PERIPHERAL;
341 		break;
342 	case OTG_STATE_B_PERIPHERAL:
343 		if (!otg_ctrl->b_sess_vld || otg_ctrl->id == 0)
344 			mvotg->phy.otg->state = OTG_STATE_B_IDLE;
345 		break;
346 	case OTG_STATE_A_IDLE:
347 		if (otg_ctrl->id)
348 			mvotg->phy.otg->state = OTG_STATE_B_IDLE;
349 		else if (!(otg_ctrl->a_bus_drop) &&
350 			 (otg_ctrl->a_bus_req || otg_ctrl->a_srp_det))
351 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_VRISE;
352 		break;
353 	case OTG_STATE_A_WAIT_VRISE:
354 		if (otg_ctrl->a_vbus_vld)
355 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
356 		break;
357 	case OTG_STATE_A_WAIT_BCON:
358 		if (otg_ctrl->id || otg_ctrl->a_bus_drop
359 		    || otg_ctrl->a_wait_bcon_timeout) {
360 			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
361 			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
362 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_VFALL;
363 			otg_ctrl->a_bus_req = 0;
364 		} else if (!otg_ctrl->a_vbus_vld) {
365 			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
366 			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
367 			mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
368 		} else if (otg_ctrl->b_conn) {
369 			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
370 			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
371 			mvotg->phy.otg->state = OTG_STATE_A_HOST;
372 		}
373 		break;
374 	case OTG_STATE_A_HOST:
375 		if (otg_ctrl->id || !otg_ctrl->b_conn
376 		    || otg_ctrl->a_bus_drop)
377 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
378 		else if (!otg_ctrl->a_vbus_vld)
379 			mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
380 		break;
381 	case OTG_STATE_A_WAIT_VFALL:
382 		if (otg_ctrl->id
383 		    || (!otg_ctrl->b_conn && otg_ctrl->a_sess_vld)
384 		    || otg_ctrl->a_bus_req)
385 			mvotg->phy.otg->state = OTG_STATE_A_IDLE;
386 		break;
387 	case OTG_STATE_A_VBUS_ERR:
388 		if (otg_ctrl->id || otg_ctrl->a_clr_err
389 		    || otg_ctrl->a_bus_drop) {
390 			otg_ctrl->a_clr_err = 0;
391 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_VFALL;
392 		}
393 		break;
394 	default:
395 		break;
396 	}
397 }
398 
399 static void mv_otg_work(struct work_struct *work)
400 {
401 	struct mv_otg *mvotg;
402 	struct usb_otg *otg;
403 	int old_state;
404 
405 	mvotg = container_of(to_delayed_work(work), struct mv_otg, work);
406 
407 run:
408 	/* work queue is single thread, or we need spin_lock to protect */
409 	otg = mvotg->phy.otg;
410 	old_state = otg->state;
411 
412 	if (!mvotg->active)
413 		return;
414 
415 	mv_otg_update_inputs(mvotg);
416 	mv_otg_update_state(mvotg);
417 
418 	if (old_state != mvotg->phy.otg->state) {
419 		dev_info(&mvotg->pdev->dev, "change from state %s to %s\n",
420 			 state_string[old_state],
421 			 state_string[mvotg->phy.otg->state]);
422 
423 		switch (mvotg->phy.otg->state) {
424 		case OTG_STATE_B_IDLE:
425 			otg->default_a = 0;
426 			if (old_state == OTG_STATE_B_PERIPHERAL)
427 				mv_otg_start_periphrals(mvotg, 0);
428 			mv_otg_reset(mvotg);
429 			mv_otg_disable(mvotg);
430 			usb_phy_set_event(&mvotg->phy, USB_EVENT_NONE);
431 			break;
432 		case OTG_STATE_B_PERIPHERAL:
433 			mv_otg_enable(mvotg);
434 			mv_otg_start_periphrals(mvotg, 1);
435 			usb_phy_set_event(&mvotg->phy, USB_EVENT_ENUMERATED);
436 			break;
437 		case OTG_STATE_A_IDLE:
438 			otg->default_a = 1;
439 			mv_otg_enable(mvotg);
440 			if (old_state == OTG_STATE_A_WAIT_VFALL)
441 				mv_otg_start_host(mvotg, 0);
442 			mv_otg_reset(mvotg);
443 			break;
444 		case OTG_STATE_A_WAIT_VRISE:
445 			mv_otg_set_vbus(otg, 1);
446 			break;
447 		case OTG_STATE_A_WAIT_BCON:
448 			if (old_state != OTG_STATE_A_HOST)
449 				mv_otg_start_host(mvotg, 1);
450 			mv_otg_set_timer(mvotg, A_WAIT_BCON_TIMER,
451 					 T_A_WAIT_BCON);
452 			/*
453 			 * Now, we directly enter A_HOST. So set b_conn = 1
454 			 * here. In fact, it need host driver to notify us.
455 			 */
456 			mvotg->otg_ctrl.b_conn = 1;
457 			break;
458 		case OTG_STATE_A_HOST:
459 			break;
460 		case OTG_STATE_A_WAIT_VFALL:
461 			/*
462 			 * Now, we has exited A_HOST. So set b_conn = 0
463 			 * here. In fact, it need host driver to notify us.
464 			 */
465 			mvotg->otg_ctrl.b_conn = 0;
466 			mv_otg_set_vbus(otg, 0);
467 			break;
468 		case OTG_STATE_A_VBUS_ERR:
469 			break;
470 		default:
471 			break;
472 		}
473 		goto run;
474 	}
475 }
476 
477 static irqreturn_t mv_otg_irq(int irq, void *dev)
478 {
479 	struct mv_otg *mvotg = dev;
480 	u32 otgsc;
481 
482 	otgsc = readl(&mvotg->op_regs->otgsc);
483 	writel(otgsc, &mvotg->op_regs->otgsc);
484 
485 	/*
486 	 * if we have vbus, then the vbus detection for B-device
487 	 * will be done by mv_otg_inputs_irq().
488 	 */
489 	if (mvotg->pdata->vbus)
490 		if ((otgsc & OTGSC_STS_USB_ID) &&
491 		    !(otgsc & OTGSC_INTSTS_USB_ID))
492 			return IRQ_NONE;
493 
494 	if ((otgsc & mvotg->irq_status) == 0)
495 		return IRQ_NONE;
496 
497 	mv_otg_run_state_machine(mvotg, 0);
498 
499 	return IRQ_HANDLED;
500 }
501 
502 static irqreturn_t mv_otg_inputs_irq(int irq, void *dev)
503 {
504 	struct mv_otg *mvotg = dev;
505 
506 	/* The clock may disabled at this time */
507 	if (!mvotg->active) {
508 		mv_otg_enable(mvotg);
509 		mv_otg_init_irq(mvotg);
510 	}
511 
512 	mv_otg_run_state_machine(mvotg, 0);
513 
514 	return IRQ_HANDLED;
515 }
516 
517 static ssize_t
518 a_bus_req_show(struct device *dev, struct device_attribute *attr, char *buf)
519 {
520 	struct mv_otg *mvotg = dev_get_drvdata(dev);
521 	return scnprintf(buf, PAGE_SIZE, "%d\n",
522 			 mvotg->otg_ctrl.a_bus_req);
523 }
524 
525 static ssize_t
526 a_bus_req_store(struct device *dev, struct device_attribute *attr,
527 	      const char *buf, size_t count)
528 {
529 	struct mv_otg *mvotg = dev_get_drvdata(dev);
530 
531 	if (count > 2)
532 		return -1;
533 
534 	/* We will use this interface to change to A device */
535 	if (mvotg->phy.otg->state != OTG_STATE_B_IDLE
536 	    && mvotg->phy.otg->state != OTG_STATE_A_IDLE)
537 		return -1;
538 
539 	/* The clock may disabled and we need to set irq for ID detected */
540 	mv_otg_enable(mvotg);
541 	mv_otg_init_irq(mvotg);
542 
543 	if (buf[0] == '1') {
544 		mvotg->otg_ctrl.a_bus_req = 1;
545 		mvotg->otg_ctrl.a_bus_drop = 0;
546 		dev_dbg(&mvotg->pdev->dev,
547 			"User request: a_bus_req = 1\n");
548 
549 		if (spin_trylock(&mvotg->wq_lock)) {
550 			mv_otg_run_state_machine(mvotg, 0);
551 			spin_unlock(&mvotg->wq_lock);
552 		}
553 	}
554 
555 	return count;
556 }
557 
558 static DEVICE_ATTR_RW(a_bus_req);
559 
560 static ssize_t
561 a_clr_err_store(struct device *dev, struct device_attribute *attr,
562 	      const char *buf, size_t count)
563 {
564 	struct mv_otg *mvotg = dev_get_drvdata(dev);
565 	if (!mvotg->phy.otg->default_a)
566 		return -1;
567 
568 	if (count > 2)
569 		return -1;
570 
571 	if (buf[0] == '1') {
572 		mvotg->otg_ctrl.a_clr_err = 1;
573 		dev_dbg(&mvotg->pdev->dev,
574 			"User request: a_clr_err = 1\n");
575 	}
576 
577 	if (spin_trylock(&mvotg->wq_lock)) {
578 		mv_otg_run_state_machine(mvotg, 0);
579 		spin_unlock(&mvotg->wq_lock);
580 	}
581 
582 	return count;
583 }
584 
585 static DEVICE_ATTR_WO(a_clr_err);
586 
587 static ssize_t
588 a_bus_drop_show(struct device *dev, struct device_attribute *attr,
589 	       char *buf)
590 {
591 	struct mv_otg *mvotg = dev_get_drvdata(dev);
592 	return scnprintf(buf, PAGE_SIZE, "%d\n",
593 			 mvotg->otg_ctrl.a_bus_drop);
594 }
595 
596 static ssize_t
597 a_bus_drop_store(struct device *dev, struct device_attribute *attr,
598 	       const char *buf, size_t count)
599 {
600 	struct mv_otg *mvotg = dev_get_drvdata(dev);
601 	if (!mvotg->phy.otg->default_a)
602 		return -1;
603 
604 	if (count > 2)
605 		return -1;
606 
607 	if (buf[0] == '0') {
608 		mvotg->otg_ctrl.a_bus_drop = 0;
609 		dev_dbg(&mvotg->pdev->dev,
610 			"User request: a_bus_drop = 0\n");
611 	} else if (buf[0] == '1') {
612 		mvotg->otg_ctrl.a_bus_drop = 1;
613 		mvotg->otg_ctrl.a_bus_req = 0;
614 		dev_dbg(&mvotg->pdev->dev,
615 			"User request: a_bus_drop = 1\n");
616 		dev_dbg(&mvotg->pdev->dev,
617 			"User request: and a_bus_req = 0\n");
618 	}
619 
620 	if (spin_trylock(&mvotg->wq_lock)) {
621 		mv_otg_run_state_machine(mvotg, 0);
622 		spin_unlock(&mvotg->wq_lock);
623 	}
624 
625 	return count;
626 }
627 
628 static DEVICE_ATTR_RW(a_bus_drop);
629 
630 static struct attribute *inputs_attrs[] = {
631 	&dev_attr_a_bus_req.attr,
632 	&dev_attr_a_clr_err.attr,
633 	&dev_attr_a_bus_drop.attr,
634 	NULL,
635 };
636 
637 static const struct attribute_group inputs_attr_group = {
638 	.name = "inputs",
639 	.attrs = inputs_attrs,
640 };
641 
642 static const struct attribute_group *mv_otg_groups[] = {
643 	&inputs_attr_group,
644 	NULL,
645 };
646 
647 static int mv_otg_remove(struct platform_device *pdev)
648 {
649 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
650 
651 	if (mvotg->qwork)
652 		destroy_workqueue(mvotg->qwork);
653 
654 	mv_otg_disable(mvotg);
655 
656 	usb_remove_phy(&mvotg->phy);
657 
658 	return 0;
659 }
660 
661 static int mv_otg_probe(struct platform_device *pdev)
662 {
663 	struct mv_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
664 	struct mv_otg *mvotg;
665 	struct usb_otg *otg;
666 	struct resource *r;
667 	int retval = 0, i;
668 
669 	if (pdata == NULL) {
670 		dev_err(&pdev->dev, "failed to get platform data\n");
671 		return -ENODEV;
672 	}
673 
674 	mvotg = devm_kzalloc(&pdev->dev, sizeof(*mvotg), GFP_KERNEL);
675 	if (!mvotg)
676 		return -ENOMEM;
677 
678 	otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
679 	if (!otg)
680 		return -ENOMEM;
681 
682 	platform_set_drvdata(pdev, mvotg);
683 
684 	mvotg->pdev = pdev;
685 	mvotg->pdata = pdata;
686 
687 	mvotg->clk = devm_clk_get(&pdev->dev, NULL);
688 	if (IS_ERR(mvotg->clk))
689 		return PTR_ERR(mvotg->clk);
690 
691 	mvotg->qwork = create_singlethread_workqueue("mv_otg_queue");
692 	if (!mvotg->qwork) {
693 		dev_dbg(&pdev->dev, "cannot create workqueue for OTG\n");
694 		return -ENOMEM;
695 	}
696 
697 	INIT_DELAYED_WORK(&mvotg->work, mv_otg_work);
698 
699 	/* OTG common part */
700 	mvotg->pdev = pdev;
701 	mvotg->phy.dev = &pdev->dev;
702 	mvotg->phy.otg = otg;
703 	mvotg->phy.label = driver_name;
704 
705 	otg->state = OTG_STATE_UNDEFINED;
706 	otg->usb_phy = &mvotg->phy;
707 	otg->set_host = mv_otg_set_host;
708 	otg->set_peripheral = mv_otg_set_peripheral;
709 	otg->set_vbus = mv_otg_set_vbus;
710 
711 	for (i = 0; i < OTG_TIMER_NUM; i++)
712 		timer_setup(&mvotg->otg_ctrl.timer[i],
713 			    mv_otg_timer_await_bcon, 0);
714 
715 	r = platform_get_resource_byname(mvotg->pdev,
716 					 IORESOURCE_MEM, "phyregs");
717 	if (r == NULL) {
718 		dev_err(&pdev->dev, "no phy I/O memory resource defined\n");
719 		retval = -ENODEV;
720 		goto err_destroy_workqueue;
721 	}
722 
723 	mvotg->phy_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
724 	if (mvotg->phy_regs == NULL) {
725 		dev_err(&pdev->dev, "failed to map phy I/O memory\n");
726 		retval = -EFAULT;
727 		goto err_destroy_workqueue;
728 	}
729 
730 	r = platform_get_resource_byname(mvotg->pdev,
731 					 IORESOURCE_MEM, "capregs");
732 	if (r == NULL) {
733 		dev_err(&pdev->dev, "no I/O memory resource defined\n");
734 		retval = -ENODEV;
735 		goto err_destroy_workqueue;
736 	}
737 
738 	mvotg->cap_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
739 	if (mvotg->cap_regs == NULL) {
740 		dev_err(&pdev->dev, "failed to map I/O memory\n");
741 		retval = -EFAULT;
742 		goto err_destroy_workqueue;
743 	}
744 
745 	/* we will acces controller register, so enable the udc controller */
746 	retval = mv_otg_enable_internal(mvotg);
747 	if (retval) {
748 		dev_err(&pdev->dev, "mv otg enable error %d\n", retval);
749 		goto err_destroy_workqueue;
750 	}
751 
752 	mvotg->op_regs =
753 		(struct mv_otg_regs __iomem *) ((unsigned long) mvotg->cap_regs
754 			+ (readl(mvotg->cap_regs) & CAPLENGTH_MASK));
755 
756 	if (pdata->id) {
757 		retval = devm_request_threaded_irq(&pdev->dev, pdata->id->irq,
758 						NULL, mv_otg_inputs_irq,
759 						IRQF_ONESHOT, "id", mvotg);
760 		if (retval) {
761 			dev_info(&pdev->dev,
762 				 "Failed to request irq for ID\n");
763 			pdata->id = NULL;
764 		}
765 	}
766 
767 	if (pdata->vbus) {
768 		mvotg->clock_gating = 1;
769 		retval = devm_request_threaded_irq(&pdev->dev, pdata->vbus->irq,
770 						NULL, mv_otg_inputs_irq,
771 						IRQF_ONESHOT, "vbus", mvotg);
772 		if (retval) {
773 			dev_info(&pdev->dev,
774 				 "Failed to request irq for VBUS, "
775 				 "disable clock gating\n");
776 			mvotg->clock_gating = 0;
777 			pdata->vbus = NULL;
778 		}
779 	}
780 
781 	if (pdata->disable_otg_clock_gating)
782 		mvotg->clock_gating = 0;
783 
784 	mv_otg_reset(mvotg);
785 	mv_otg_init_irq(mvotg);
786 
787 	r = platform_get_resource(mvotg->pdev, IORESOURCE_IRQ, 0);
788 	if (r == NULL) {
789 		dev_err(&pdev->dev, "no IRQ resource defined\n");
790 		retval = -ENODEV;
791 		goto err_disable_clk;
792 	}
793 
794 	mvotg->irq = r->start;
795 	if (devm_request_irq(&pdev->dev, mvotg->irq, mv_otg_irq, IRQF_SHARED,
796 			driver_name, mvotg)) {
797 		dev_err(&pdev->dev, "Request irq %d for OTG failed\n",
798 			mvotg->irq);
799 		mvotg->irq = 0;
800 		retval = -ENODEV;
801 		goto err_disable_clk;
802 	}
803 
804 	retval = usb_add_phy(&mvotg->phy, USB_PHY_TYPE_USB2);
805 	if (retval < 0) {
806 		dev_err(&pdev->dev, "can't register transceiver, %d\n",
807 			retval);
808 		goto err_disable_clk;
809 	}
810 
811 	spin_lock_init(&mvotg->wq_lock);
812 	if (spin_trylock(&mvotg->wq_lock)) {
813 		mv_otg_run_state_machine(mvotg, 2 * HZ);
814 		spin_unlock(&mvotg->wq_lock);
815 	}
816 
817 	dev_info(&pdev->dev,
818 		 "successful probe OTG device %s clock gating.\n",
819 		 mvotg->clock_gating ? "with" : "without");
820 
821 	return 0;
822 
823 err_disable_clk:
824 	mv_otg_disable_internal(mvotg);
825 err_destroy_workqueue:
826 	destroy_workqueue(mvotg->qwork);
827 
828 	return retval;
829 }
830 
831 #ifdef CONFIG_PM
832 static int mv_otg_suspend(struct platform_device *pdev, pm_message_t state)
833 {
834 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
835 
836 	if (mvotg->phy.otg->state != OTG_STATE_B_IDLE) {
837 		dev_info(&pdev->dev,
838 			 "OTG state is not B_IDLE, it is %d!\n",
839 			 mvotg->phy.otg->state);
840 		return -EAGAIN;
841 	}
842 
843 	if (!mvotg->clock_gating)
844 		mv_otg_disable_internal(mvotg);
845 
846 	return 0;
847 }
848 
849 static int mv_otg_resume(struct platform_device *pdev)
850 {
851 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
852 	u32 otgsc;
853 
854 	if (!mvotg->clock_gating) {
855 		mv_otg_enable_internal(mvotg);
856 
857 		otgsc = readl(&mvotg->op_regs->otgsc);
858 		otgsc |= mvotg->irq_en;
859 		writel(otgsc, &mvotg->op_regs->otgsc);
860 
861 		if (spin_trylock(&mvotg->wq_lock)) {
862 			mv_otg_run_state_machine(mvotg, 0);
863 			spin_unlock(&mvotg->wq_lock);
864 		}
865 	}
866 	return 0;
867 }
868 #endif
869 
870 static struct platform_driver mv_otg_driver = {
871 	.probe = mv_otg_probe,
872 	.remove = mv_otg_remove,
873 	.driver = {
874 		   .name = driver_name,
875 		   .dev_groups = mv_otg_groups,
876 		   },
877 #ifdef CONFIG_PM
878 	.suspend = mv_otg_suspend,
879 	.resume = mv_otg_resume,
880 #endif
881 };
882 module_platform_driver(mv_otg_driver);
883