xref: /openbmc/linux/drivers/usb/phy/phy-mv-usb.c (revision e52a6321)
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/uaccess.h>
12 #include <linux/device.h>
13 #include <linux/proc_fs.h>
14 #include <linux/clk.h>
15 #include <linux/workqueue.h>
16 #include <linux/platform_device.h>
17 
18 #include <linux/usb.h>
19 #include <linux/usb/ch9.h>
20 #include <linux/usb/otg.h>
21 #include <linux/usb/gadget.h>
22 #include <linux/usb/hcd.h>
23 #include <linux/platform_data/mv_usb.h>
24 
25 #include "phy-mv-usb.h"
26 
27 #define	DRIVER_DESC	"Marvell USB OTG transceiver driver"
28 
29 MODULE_DESCRIPTION(DRIVER_DESC);
30 MODULE_LICENSE("GPL");
31 
32 static const char driver_name[] = "mv-otg";
33 
34 static char *state_string[] = {
35 	"undefined",
36 	"b_idle",
37 	"b_srp_init",
38 	"b_peripheral",
39 	"b_wait_acon",
40 	"b_host",
41 	"a_idle",
42 	"a_wait_vrise",
43 	"a_wait_bcon",
44 	"a_host",
45 	"a_suspend",
46 	"a_peripheral",
47 	"a_wait_vfall",
48 	"a_vbus_err"
49 };
50 
51 static int mv_otg_set_vbus(struct usb_otg *otg, bool on)
52 {
53 	struct mv_otg *mvotg = container_of(otg->usb_phy, struct mv_otg, phy);
54 	if (mvotg->pdata->set_vbus == NULL)
55 		return -ENODEV;
56 
57 	return mvotg->pdata->set_vbus(on);
58 }
59 
60 static int mv_otg_set_host(struct usb_otg *otg,
61 			   struct usb_bus *host)
62 {
63 	otg->host = host;
64 
65 	return 0;
66 }
67 
68 static int mv_otg_set_peripheral(struct usb_otg *otg,
69 				 struct usb_gadget *gadget)
70 {
71 	otg->gadget = gadget;
72 
73 	return 0;
74 }
75 
76 static void mv_otg_run_state_machine(struct mv_otg *mvotg,
77 				     unsigned long delay)
78 {
79 	dev_dbg(&mvotg->pdev->dev, "transceiver is updated\n");
80 	if (!mvotg->qwork)
81 		return;
82 
83 	queue_delayed_work(mvotg->qwork, &mvotg->work, delay);
84 }
85 
86 static void mv_otg_timer_await_bcon(struct timer_list *t)
87 {
88 	struct mv_otg *mvotg = from_timer(mvotg, t,
89 					  otg_ctrl.timer[A_WAIT_BCON_TIMER]);
90 
91 	mvotg->otg_ctrl.a_wait_bcon_timeout = 1;
92 
93 	dev_info(&mvotg->pdev->dev, "B Device No Response!\n");
94 
95 	if (spin_trylock(&mvotg->wq_lock)) {
96 		mv_otg_run_state_machine(mvotg, 0);
97 		spin_unlock(&mvotg->wq_lock);
98 	}
99 }
100 
101 static int mv_otg_cancel_timer(struct mv_otg *mvotg, unsigned int id)
102 {
103 	struct timer_list *timer;
104 
105 	if (id >= OTG_TIMER_NUM)
106 		return -EINVAL;
107 
108 	timer = &mvotg->otg_ctrl.timer[id];
109 
110 	if (timer_pending(timer))
111 		del_timer(timer);
112 
113 	return 0;
114 }
115 
116 static int mv_otg_set_timer(struct mv_otg *mvotg, unsigned int id,
117 			    unsigned long interval)
118 {
119 	struct timer_list *timer;
120 
121 	if (id >= OTG_TIMER_NUM)
122 		return -EINVAL;
123 
124 	timer = &mvotg->otg_ctrl.timer[id];
125 	if (timer_pending(timer)) {
126 		dev_err(&mvotg->pdev->dev, "Timer%d is already running\n", id);
127 		return -EBUSY;
128 	}
129 
130 	timer->expires = jiffies + interval;
131 	add_timer(timer);
132 
133 	return 0;
134 }
135 
136 static int mv_otg_reset(struct mv_otg *mvotg)
137 {
138 	unsigned int loops;
139 	u32 tmp;
140 
141 	/* Stop the controller */
142 	tmp = readl(&mvotg->op_regs->usbcmd);
143 	tmp &= ~USBCMD_RUN_STOP;
144 	writel(tmp, &mvotg->op_regs->usbcmd);
145 
146 	/* Reset the controller to get default values */
147 	writel(USBCMD_CTRL_RESET, &mvotg->op_regs->usbcmd);
148 
149 	loops = 500;
150 	while (readl(&mvotg->op_regs->usbcmd) & USBCMD_CTRL_RESET) {
151 		if (loops == 0) {
152 			dev_err(&mvotg->pdev->dev,
153 				"Wait for RESET completed TIMEOUT\n");
154 			return -ETIMEDOUT;
155 		}
156 		loops--;
157 		udelay(20);
158 	}
159 
160 	writel(0x0, &mvotg->op_regs->usbintr);
161 	tmp = readl(&mvotg->op_regs->usbsts);
162 	writel(tmp, &mvotg->op_regs->usbsts);
163 
164 	return 0;
165 }
166 
167 static void mv_otg_init_irq(struct mv_otg *mvotg)
168 {
169 	u32 otgsc;
170 
171 	mvotg->irq_en = OTGSC_INTR_A_SESSION_VALID
172 	    | OTGSC_INTR_A_VBUS_VALID;
173 	mvotg->irq_status = OTGSC_INTSTS_A_SESSION_VALID
174 	    | OTGSC_INTSTS_A_VBUS_VALID;
175 
176 	if (mvotg->pdata->vbus == NULL) {
177 		mvotg->irq_en |= OTGSC_INTR_B_SESSION_VALID
178 		    | OTGSC_INTR_B_SESSION_END;
179 		mvotg->irq_status |= OTGSC_INTSTS_B_SESSION_VALID
180 		    | OTGSC_INTSTS_B_SESSION_END;
181 	}
182 
183 	if (mvotg->pdata->id == NULL) {
184 		mvotg->irq_en |= OTGSC_INTR_USB_ID;
185 		mvotg->irq_status |= OTGSC_INTSTS_USB_ID;
186 	}
187 
188 	otgsc = readl(&mvotg->op_regs->otgsc);
189 	otgsc |= mvotg->irq_en;
190 	writel(otgsc, &mvotg->op_regs->otgsc);
191 }
192 
193 static void mv_otg_start_host(struct mv_otg *mvotg, int on)
194 {
195 #ifdef CONFIG_USB
196 	struct usb_otg *otg = mvotg->phy.otg;
197 	struct usb_hcd *hcd;
198 
199 	if (!otg->host)
200 		return;
201 
202 	dev_info(&mvotg->pdev->dev, "%s host\n", on ? "start" : "stop");
203 
204 	hcd = bus_to_hcd(otg->host);
205 
206 	if (on) {
207 		usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
208 		device_wakeup_enable(hcd->self.controller);
209 	} else {
210 		usb_remove_hcd(hcd);
211 	}
212 #endif /* CONFIG_USB */
213 }
214 
215 static void mv_otg_start_periphrals(struct mv_otg *mvotg, int on)
216 {
217 	struct usb_otg *otg = mvotg->phy.otg;
218 
219 	if (!otg->gadget)
220 		return;
221 
222 	dev_info(mvotg->phy.dev, "gadget %s\n", on ? "on" : "off");
223 
224 	if (on)
225 		usb_gadget_vbus_connect(otg->gadget);
226 	else
227 		usb_gadget_vbus_disconnect(otg->gadget);
228 }
229 
230 static void otg_clock_enable(struct mv_otg *mvotg)
231 {
232 	clk_prepare_enable(mvotg->clk);
233 }
234 
235 static void otg_clock_disable(struct mv_otg *mvotg)
236 {
237 	clk_disable_unprepare(mvotg->clk);
238 }
239 
240 static int mv_otg_enable_internal(struct mv_otg *mvotg)
241 {
242 	int retval = 0;
243 
244 	if (mvotg->active)
245 		return 0;
246 
247 	dev_dbg(&mvotg->pdev->dev, "otg enabled\n");
248 
249 	otg_clock_enable(mvotg);
250 	if (mvotg->pdata->phy_init) {
251 		retval = mvotg->pdata->phy_init(mvotg->phy_regs);
252 		if (retval) {
253 			dev_err(&mvotg->pdev->dev,
254 				"init phy error %d\n", retval);
255 			otg_clock_disable(mvotg);
256 			return retval;
257 		}
258 	}
259 	mvotg->active = 1;
260 
261 	return 0;
262 
263 }
264 
265 static int mv_otg_enable(struct mv_otg *mvotg)
266 {
267 	if (mvotg->clock_gating)
268 		return mv_otg_enable_internal(mvotg);
269 
270 	return 0;
271 }
272 
273 static void mv_otg_disable_internal(struct mv_otg *mvotg)
274 {
275 	if (mvotg->active) {
276 		dev_dbg(&mvotg->pdev->dev, "otg disabled\n");
277 		if (mvotg->pdata->phy_deinit)
278 			mvotg->pdata->phy_deinit(mvotg->phy_regs);
279 		otg_clock_disable(mvotg);
280 		mvotg->active = 0;
281 	}
282 }
283 
284 static void mv_otg_disable(struct mv_otg *mvotg)
285 {
286 	if (mvotg->clock_gating)
287 		mv_otg_disable_internal(mvotg);
288 }
289 
290 static void mv_otg_update_inputs(struct mv_otg *mvotg)
291 {
292 	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
293 	u32 otgsc;
294 
295 	otgsc = readl(&mvotg->op_regs->otgsc);
296 
297 	if (mvotg->pdata->vbus) {
298 		if (mvotg->pdata->vbus->poll() == VBUS_HIGH) {
299 			otg_ctrl->b_sess_vld = 1;
300 			otg_ctrl->b_sess_end = 0;
301 		} else {
302 			otg_ctrl->b_sess_vld = 0;
303 			otg_ctrl->b_sess_end = 1;
304 		}
305 	} else {
306 		otg_ctrl->b_sess_vld = !!(otgsc & OTGSC_STS_B_SESSION_VALID);
307 		otg_ctrl->b_sess_end = !!(otgsc & OTGSC_STS_B_SESSION_END);
308 	}
309 
310 	if (mvotg->pdata->id)
311 		otg_ctrl->id = !!mvotg->pdata->id->poll();
312 	else
313 		otg_ctrl->id = !!(otgsc & OTGSC_STS_USB_ID);
314 
315 	if (mvotg->pdata->otg_force_a_bus_req && !otg_ctrl->id)
316 		otg_ctrl->a_bus_req = 1;
317 
318 	otg_ctrl->a_sess_vld = !!(otgsc & OTGSC_STS_A_SESSION_VALID);
319 	otg_ctrl->a_vbus_vld = !!(otgsc & OTGSC_STS_A_VBUS_VALID);
320 
321 	dev_dbg(&mvotg->pdev->dev, "%s: ", __func__);
322 	dev_dbg(&mvotg->pdev->dev, "id %d\n", otg_ctrl->id);
323 	dev_dbg(&mvotg->pdev->dev, "b_sess_vld %d\n", otg_ctrl->b_sess_vld);
324 	dev_dbg(&mvotg->pdev->dev, "b_sess_end %d\n", otg_ctrl->b_sess_end);
325 	dev_dbg(&mvotg->pdev->dev, "a_vbus_vld %d\n", otg_ctrl->a_vbus_vld);
326 	dev_dbg(&mvotg->pdev->dev, "a_sess_vld %d\n", otg_ctrl->a_sess_vld);
327 }
328 
329 static void mv_otg_update_state(struct mv_otg *mvotg)
330 {
331 	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
332 	int old_state = mvotg->phy.otg->state;
333 
334 	switch (old_state) {
335 	case OTG_STATE_UNDEFINED:
336 		mvotg->phy.otg->state = OTG_STATE_B_IDLE;
337 		/* FALL THROUGH */
338 	case OTG_STATE_B_IDLE:
339 		if (otg_ctrl->id == 0)
340 			mvotg->phy.otg->state = OTG_STATE_A_IDLE;
341 		else if (otg_ctrl->b_sess_vld)
342 			mvotg->phy.otg->state = OTG_STATE_B_PERIPHERAL;
343 		break;
344 	case OTG_STATE_B_PERIPHERAL:
345 		if (!otg_ctrl->b_sess_vld || otg_ctrl->id == 0)
346 			mvotg->phy.otg->state = OTG_STATE_B_IDLE;
347 		break;
348 	case OTG_STATE_A_IDLE:
349 		if (otg_ctrl->id)
350 			mvotg->phy.otg->state = OTG_STATE_B_IDLE;
351 		else if (!(otg_ctrl->a_bus_drop) &&
352 			 (otg_ctrl->a_bus_req || otg_ctrl->a_srp_det))
353 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_VRISE;
354 		break;
355 	case OTG_STATE_A_WAIT_VRISE:
356 		if (otg_ctrl->a_vbus_vld)
357 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
358 		break;
359 	case OTG_STATE_A_WAIT_BCON:
360 		if (otg_ctrl->id || otg_ctrl->a_bus_drop
361 		    || otg_ctrl->a_wait_bcon_timeout) {
362 			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
363 			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
364 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_VFALL;
365 			otg_ctrl->a_bus_req = 0;
366 		} else if (!otg_ctrl->a_vbus_vld) {
367 			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
368 			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
369 			mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
370 		} else if (otg_ctrl->b_conn) {
371 			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
372 			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
373 			mvotg->phy.otg->state = OTG_STATE_A_HOST;
374 		}
375 		break;
376 	case OTG_STATE_A_HOST:
377 		if (otg_ctrl->id || !otg_ctrl->b_conn
378 		    || otg_ctrl->a_bus_drop)
379 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
380 		else if (!otg_ctrl->a_vbus_vld)
381 			mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
382 		break;
383 	case OTG_STATE_A_WAIT_VFALL:
384 		if (otg_ctrl->id
385 		    || (!otg_ctrl->b_conn && otg_ctrl->a_sess_vld)
386 		    || otg_ctrl->a_bus_req)
387 			mvotg->phy.otg->state = OTG_STATE_A_IDLE;
388 		break;
389 	case OTG_STATE_A_VBUS_ERR:
390 		if (otg_ctrl->id || otg_ctrl->a_clr_err
391 		    || otg_ctrl->a_bus_drop) {
392 			otg_ctrl->a_clr_err = 0;
393 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_VFALL;
394 		}
395 		break;
396 	default:
397 		break;
398 	}
399 }
400 
401 static void mv_otg_work(struct work_struct *work)
402 {
403 	struct mv_otg *mvotg;
404 	struct usb_otg *otg;
405 	int old_state;
406 
407 	mvotg = container_of(to_delayed_work(work), struct mv_otg, work);
408 
409 run:
410 	/* work queue is single thread, or we need spin_lock to protect */
411 	otg = mvotg->phy.otg;
412 	old_state = otg->state;
413 
414 	if (!mvotg->active)
415 		return;
416 
417 	mv_otg_update_inputs(mvotg);
418 	mv_otg_update_state(mvotg);
419 
420 	if (old_state != mvotg->phy.otg->state) {
421 		dev_info(&mvotg->pdev->dev, "change from state %s to %s\n",
422 			 state_string[old_state],
423 			 state_string[mvotg->phy.otg->state]);
424 
425 		switch (mvotg->phy.otg->state) {
426 		case OTG_STATE_B_IDLE:
427 			otg->default_a = 0;
428 			if (old_state == OTG_STATE_B_PERIPHERAL)
429 				mv_otg_start_periphrals(mvotg, 0);
430 			mv_otg_reset(mvotg);
431 			mv_otg_disable(mvotg);
432 			usb_phy_set_event(&mvotg->phy, USB_EVENT_NONE);
433 			break;
434 		case OTG_STATE_B_PERIPHERAL:
435 			mv_otg_enable(mvotg);
436 			mv_otg_start_periphrals(mvotg, 1);
437 			usb_phy_set_event(&mvotg->phy, USB_EVENT_ENUMERATED);
438 			break;
439 		case OTG_STATE_A_IDLE:
440 			otg->default_a = 1;
441 			mv_otg_enable(mvotg);
442 			if (old_state == OTG_STATE_A_WAIT_VFALL)
443 				mv_otg_start_host(mvotg, 0);
444 			mv_otg_reset(mvotg);
445 			break;
446 		case OTG_STATE_A_WAIT_VRISE:
447 			mv_otg_set_vbus(otg, 1);
448 			break;
449 		case OTG_STATE_A_WAIT_BCON:
450 			if (old_state != OTG_STATE_A_HOST)
451 				mv_otg_start_host(mvotg, 1);
452 			mv_otg_set_timer(mvotg, A_WAIT_BCON_TIMER,
453 					 T_A_WAIT_BCON);
454 			/*
455 			 * Now, we directly enter A_HOST. So set b_conn = 1
456 			 * here. In fact, it need host driver to notify us.
457 			 */
458 			mvotg->otg_ctrl.b_conn = 1;
459 			break;
460 		case OTG_STATE_A_HOST:
461 			break;
462 		case OTG_STATE_A_WAIT_VFALL:
463 			/*
464 			 * Now, we has exited A_HOST. So set b_conn = 0
465 			 * here. In fact, it need host driver to notify us.
466 			 */
467 			mvotg->otg_ctrl.b_conn = 0;
468 			mv_otg_set_vbus(otg, 0);
469 			break;
470 		case OTG_STATE_A_VBUS_ERR:
471 			break;
472 		default:
473 			break;
474 		}
475 		goto run;
476 	}
477 }
478 
479 static irqreturn_t mv_otg_irq(int irq, void *dev)
480 {
481 	struct mv_otg *mvotg = dev;
482 	u32 otgsc;
483 
484 	otgsc = readl(&mvotg->op_regs->otgsc);
485 	writel(otgsc, &mvotg->op_regs->otgsc);
486 
487 	/*
488 	 * if we have vbus, then the vbus detection for B-device
489 	 * will be done by mv_otg_inputs_irq().
490 	 */
491 	if (mvotg->pdata->vbus)
492 		if ((otgsc & OTGSC_STS_USB_ID) &&
493 		    !(otgsc & OTGSC_INTSTS_USB_ID))
494 			return IRQ_NONE;
495 
496 	if ((otgsc & mvotg->irq_status) == 0)
497 		return IRQ_NONE;
498 
499 	mv_otg_run_state_machine(mvotg, 0);
500 
501 	return IRQ_HANDLED;
502 }
503 
504 static irqreturn_t mv_otg_inputs_irq(int irq, void *dev)
505 {
506 	struct mv_otg *mvotg = dev;
507 
508 	/* The clock may disabled at this time */
509 	if (!mvotg->active) {
510 		mv_otg_enable(mvotg);
511 		mv_otg_init_irq(mvotg);
512 	}
513 
514 	mv_otg_run_state_machine(mvotg, 0);
515 
516 	return IRQ_HANDLED;
517 }
518 
519 static ssize_t
520 a_bus_req_show(struct device *dev, struct device_attribute *attr, char *buf)
521 {
522 	struct mv_otg *mvotg = dev_get_drvdata(dev);
523 	return scnprintf(buf, PAGE_SIZE, "%d\n",
524 			 mvotg->otg_ctrl.a_bus_req);
525 }
526 
527 static ssize_t
528 a_bus_req_store(struct device *dev, struct device_attribute *attr,
529 	      const char *buf, size_t count)
530 {
531 	struct mv_otg *mvotg = dev_get_drvdata(dev);
532 
533 	if (count > 2)
534 		return -1;
535 
536 	/* We will use this interface to change to A device */
537 	if (mvotg->phy.otg->state != OTG_STATE_B_IDLE
538 	    && mvotg->phy.otg->state != OTG_STATE_A_IDLE)
539 		return -1;
540 
541 	/* The clock may disabled and we need to set irq for ID detected */
542 	mv_otg_enable(mvotg);
543 	mv_otg_init_irq(mvotg);
544 
545 	if (buf[0] == '1') {
546 		mvotg->otg_ctrl.a_bus_req = 1;
547 		mvotg->otg_ctrl.a_bus_drop = 0;
548 		dev_dbg(&mvotg->pdev->dev,
549 			"User request: a_bus_req = 1\n");
550 
551 		if (spin_trylock(&mvotg->wq_lock)) {
552 			mv_otg_run_state_machine(mvotg, 0);
553 			spin_unlock(&mvotg->wq_lock);
554 		}
555 	}
556 
557 	return count;
558 }
559 
560 static DEVICE_ATTR_RW(a_bus_req);
561 
562 static ssize_t
563 a_clr_err_store(struct device *dev, struct device_attribute *attr,
564 	      const char *buf, size_t count)
565 {
566 	struct mv_otg *mvotg = dev_get_drvdata(dev);
567 	if (!mvotg->phy.otg->default_a)
568 		return -1;
569 
570 	if (count > 2)
571 		return -1;
572 
573 	if (buf[0] == '1') {
574 		mvotg->otg_ctrl.a_clr_err = 1;
575 		dev_dbg(&mvotg->pdev->dev,
576 			"User request: a_clr_err = 1\n");
577 	}
578 
579 	if (spin_trylock(&mvotg->wq_lock)) {
580 		mv_otg_run_state_machine(mvotg, 0);
581 		spin_unlock(&mvotg->wq_lock);
582 	}
583 
584 	return count;
585 }
586 
587 static DEVICE_ATTR_WO(a_clr_err);
588 
589 static ssize_t
590 a_bus_drop_show(struct device *dev, struct device_attribute *attr,
591 	       char *buf)
592 {
593 	struct mv_otg *mvotg = dev_get_drvdata(dev);
594 	return scnprintf(buf, PAGE_SIZE, "%d\n",
595 			 mvotg->otg_ctrl.a_bus_drop);
596 }
597 
598 static ssize_t
599 a_bus_drop_store(struct device *dev, struct device_attribute *attr,
600 	       const char *buf, size_t count)
601 {
602 	struct mv_otg *mvotg = dev_get_drvdata(dev);
603 	if (!mvotg->phy.otg->default_a)
604 		return -1;
605 
606 	if (count > 2)
607 		return -1;
608 
609 	if (buf[0] == '0') {
610 		mvotg->otg_ctrl.a_bus_drop = 0;
611 		dev_dbg(&mvotg->pdev->dev,
612 			"User request: a_bus_drop = 0\n");
613 	} else if (buf[0] == '1') {
614 		mvotg->otg_ctrl.a_bus_drop = 1;
615 		mvotg->otg_ctrl.a_bus_req = 0;
616 		dev_dbg(&mvotg->pdev->dev,
617 			"User request: a_bus_drop = 1\n");
618 		dev_dbg(&mvotg->pdev->dev,
619 			"User request: and a_bus_req = 0\n");
620 	}
621 
622 	if (spin_trylock(&mvotg->wq_lock)) {
623 		mv_otg_run_state_machine(mvotg, 0);
624 		spin_unlock(&mvotg->wq_lock);
625 	}
626 
627 	return count;
628 }
629 
630 static DEVICE_ATTR_RW(a_bus_drop);
631 
632 static struct attribute *inputs_attrs[] = {
633 	&dev_attr_a_bus_req.attr,
634 	&dev_attr_a_clr_err.attr,
635 	&dev_attr_a_bus_drop.attr,
636 	NULL,
637 };
638 
639 static const struct attribute_group inputs_attr_group = {
640 	.name = "inputs",
641 	.attrs = inputs_attrs,
642 };
643 
644 static int mv_otg_remove(struct platform_device *pdev)
645 {
646 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
647 
648 	sysfs_remove_group(&mvotg->pdev->dev.kobj, &inputs_attr_group);
649 
650 	if (mvotg->qwork) {
651 		flush_workqueue(mvotg->qwork);
652 		destroy_workqueue(mvotg->qwork);
653 	}
654 
655 	mv_otg_disable(mvotg);
656 
657 	usb_remove_phy(&mvotg->phy);
658 
659 	return 0;
660 }
661 
662 static int mv_otg_probe(struct platform_device *pdev)
663 {
664 	struct mv_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
665 	struct mv_otg *mvotg;
666 	struct usb_otg *otg;
667 	struct resource *r;
668 	int retval = 0, i;
669 
670 	if (pdata == NULL) {
671 		dev_err(&pdev->dev, "failed to get platform data\n");
672 		return -ENODEV;
673 	}
674 
675 	mvotg = devm_kzalloc(&pdev->dev, sizeof(*mvotg), GFP_KERNEL);
676 	if (!mvotg)
677 		return -ENOMEM;
678 
679 	otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
680 	if (!otg)
681 		return -ENOMEM;
682 
683 	platform_set_drvdata(pdev, mvotg);
684 
685 	mvotg->pdev = pdev;
686 	mvotg->pdata = pdata;
687 
688 	mvotg->clk = devm_clk_get(&pdev->dev, NULL);
689 	if (IS_ERR(mvotg->clk))
690 		return PTR_ERR(mvotg->clk);
691 
692 	mvotg->qwork = create_singlethread_workqueue("mv_otg_queue");
693 	if (!mvotg->qwork) {
694 		dev_dbg(&pdev->dev, "cannot create workqueue for OTG\n");
695 		return -ENOMEM;
696 	}
697 
698 	INIT_DELAYED_WORK(&mvotg->work, mv_otg_work);
699 
700 	/* OTG common part */
701 	mvotg->pdev = pdev;
702 	mvotg->phy.dev = &pdev->dev;
703 	mvotg->phy.otg = otg;
704 	mvotg->phy.label = driver_name;
705 
706 	otg->state = OTG_STATE_UNDEFINED;
707 	otg->usb_phy = &mvotg->phy;
708 	otg->set_host = mv_otg_set_host;
709 	otg->set_peripheral = mv_otg_set_peripheral;
710 	otg->set_vbus = mv_otg_set_vbus;
711 
712 	for (i = 0; i < OTG_TIMER_NUM; i++)
713 		timer_setup(&mvotg->otg_ctrl.timer[i],
714 			    mv_otg_timer_await_bcon, 0);
715 
716 	r = platform_get_resource_byname(mvotg->pdev,
717 					 IORESOURCE_MEM, "phyregs");
718 	if (r == NULL) {
719 		dev_err(&pdev->dev, "no phy I/O memory resource defined\n");
720 		retval = -ENODEV;
721 		goto err_destroy_workqueue;
722 	}
723 
724 	mvotg->phy_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
725 	if (mvotg->phy_regs == NULL) {
726 		dev_err(&pdev->dev, "failed to map phy I/O memory\n");
727 		retval = -EFAULT;
728 		goto err_destroy_workqueue;
729 	}
730 
731 	r = platform_get_resource_byname(mvotg->pdev,
732 					 IORESOURCE_MEM, "capregs");
733 	if (r == NULL) {
734 		dev_err(&pdev->dev, "no I/O memory resource defined\n");
735 		retval = -ENODEV;
736 		goto err_destroy_workqueue;
737 	}
738 
739 	mvotg->cap_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
740 	if (mvotg->cap_regs == NULL) {
741 		dev_err(&pdev->dev, "failed to map I/O memory\n");
742 		retval = -EFAULT;
743 		goto err_destroy_workqueue;
744 	}
745 
746 	/* we will acces controller register, so enable the udc controller */
747 	retval = mv_otg_enable_internal(mvotg);
748 	if (retval) {
749 		dev_err(&pdev->dev, "mv otg enable error %d\n", retval);
750 		goto err_destroy_workqueue;
751 	}
752 
753 	mvotg->op_regs =
754 		(struct mv_otg_regs __iomem *) ((unsigned long) mvotg->cap_regs
755 			+ (readl(mvotg->cap_regs) & CAPLENGTH_MASK));
756 
757 	if (pdata->id) {
758 		retval = devm_request_threaded_irq(&pdev->dev, pdata->id->irq,
759 						NULL, mv_otg_inputs_irq,
760 						IRQF_ONESHOT, "id", mvotg);
761 		if (retval) {
762 			dev_info(&pdev->dev,
763 				 "Failed to request irq for ID\n");
764 			pdata->id = NULL;
765 		}
766 	}
767 
768 	if (pdata->vbus) {
769 		mvotg->clock_gating = 1;
770 		retval = devm_request_threaded_irq(&pdev->dev, pdata->vbus->irq,
771 						NULL, mv_otg_inputs_irq,
772 						IRQF_ONESHOT, "vbus", mvotg);
773 		if (retval) {
774 			dev_info(&pdev->dev,
775 				 "Failed to request irq for VBUS, "
776 				 "disable clock gating\n");
777 			mvotg->clock_gating = 0;
778 			pdata->vbus = NULL;
779 		}
780 	}
781 
782 	if (pdata->disable_otg_clock_gating)
783 		mvotg->clock_gating = 0;
784 
785 	mv_otg_reset(mvotg);
786 	mv_otg_init_irq(mvotg);
787 
788 	r = platform_get_resource(mvotg->pdev, IORESOURCE_IRQ, 0);
789 	if (r == NULL) {
790 		dev_err(&pdev->dev, "no IRQ resource defined\n");
791 		retval = -ENODEV;
792 		goto err_disable_clk;
793 	}
794 
795 	mvotg->irq = r->start;
796 	if (devm_request_irq(&pdev->dev, mvotg->irq, mv_otg_irq, IRQF_SHARED,
797 			driver_name, mvotg)) {
798 		dev_err(&pdev->dev, "Request irq %d for OTG failed\n",
799 			mvotg->irq);
800 		mvotg->irq = 0;
801 		retval = -ENODEV;
802 		goto err_disable_clk;
803 	}
804 
805 	retval = usb_add_phy(&mvotg->phy, USB_PHY_TYPE_USB2);
806 	if (retval < 0) {
807 		dev_err(&pdev->dev, "can't register transceiver, %d\n",
808 			retval);
809 		goto err_disable_clk;
810 	}
811 
812 	retval = sysfs_create_group(&pdev->dev.kobj, &inputs_attr_group);
813 	if (retval < 0) {
814 		dev_dbg(&pdev->dev,
815 			"Can't register sysfs attr group: %d\n", retval);
816 		goto err_remove_phy;
817 	}
818 
819 	spin_lock_init(&mvotg->wq_lock);
820 	if (spin_trylock(&mvotg->wq_lock)) {
821 		mv_otg_run_state_machine(mvotg, 2 * HZ);
822 		spin_unlock(&mvotg->wq_lock);
823 	}
824 
825 	dev_info(&pdev->dev,
826 		 "successful probe OTG device %s clock gating.\n",
827 		 mvotg->clock_gating ? "with" : "without");
828 
829 	return 0;
830 
831 err_remove_phy:
832 	usb_remove_phy(&mvotg->phy);
833 err_disable_clk:
834 	mv_otg_disable_internal(mvotg);
835 err_destroy_workqueue:
836 	flush_workqueue(mvotg->qwork);
837 	destroy_workqueue(mvotg->qwork);
838 
839 	return retval;
840 }
841 
842 #ifdef CONFIG_PM
843 static int mv_otg_suspend(struct platform_device *pdev, pm_message_t state)
844 {
845 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
846 
847 	if (mvotg->phy.otg->state != OTG_STATE_B_IDLE) {
848 		dev_info(&pdev->dev,
849 			 "OTG state is not B_IDLE, it is %d!\n",
850 			 mvotg->phy.otg->state);
851 		return -EAGAIN;
852 	}
853 
854 	if (!mvotg->clock_gating)
855 		mv_otg_disable_internal(mvotg);
856 
857 	return 0;
858 }
859 
860 static int mv_otg_resume(struct platform_device *pdev)
861 {
862 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
863 	u32 otgsc;
864 
865 	if (!mvotg->clock_gating) {
866 		mv_otg_enable_internal(mvotg);
867 
868 		otgsc = readl(&mvotg->op_regs->otgsc);
869 		otgsc |= mvotg->irq_en;
870 		writel(otgsc, &mvotg->op_regs->otgsc);
871 
872 		if (spin_trylock(&mvotg->wq_lock)) {
873 			mv_otg_run_state_machine(mvotg, 0);
874 			spin_unlock(&mvotg->wq_lock);
875 		}
876 	}
877 	return 0;
878 }
879 #endif
880 
881 static struct platform_driver mv_otg_driver = {
882 	.probe = mv_otg_probe,
883 	.remove = mv_otg_remove,
884 	.driver = {
885 		   .name = driver_name,
886 		   },
887 #ifdef CONFIG_PM
888 	.suspend = mv_otg_suspend,
889 	.resume = mv_otg_resume,
890 #endif
891 };
892 module_platform_driver(mv_otg_driver);
893