xref: /openbmc/linux/drivers/usb/phy/phy-mv-usb.c (revision 74ce1896)
1 /*
2  * Copyright (C) 2011 Marvell International Ltd. All rights reserved.
3  * Author: Chao Xie <chao.xie@marvell.com>
4  *	   Neil Zhang <zhangwm@marvell.com>
5  *
6  * This program is free software; you can redistribute  it and/or modify it
7  * under  the terms of  the GNU General  Public License as published by the
8  * Free Software Foundation;  either version 2 of the  License, or (at your
9  * option) any later version.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/io.h>
15 #include <linux/uaccess.h>
16 #include <linux/device.h>
17 #include <linux/proc_fs.h>
18 #include <linux/clk.h>
19 #include <linux/workqueue.h>
20 #include <linux/platform_device.h>
21 
22 #include <linux/usb.h>
23 #include <linux/usb/ch9.h>
24 #include <linux/usb/otg.h>
25 #include <linux/usb/gadget.h>
26 #include <linux/usb/hcd.h>
27 #include <linux/platform_data/mv_usb.h>
28 
29 #include "phy-mv-usb.h"
30 
31 #define	DRIVER_DESC	"Marvell USB OTG transceiver driver"
32 
33 MODULE_DESCRIPTION(DRIVER_DESC);
34 MODULE_LICENSE("GPL");
35 
36 static const char driver_name[] = "mv-otg";
37 
38 static char *state_string[] = {
39 	"undefined",
40 	"b_idle",
41 	"b_srp_init",
42 	"b_peripheral",
43 	"b_wait_acon",
44 	"b_host",
45 	"a_idle",
46 	"a_wait_vrise",
47 	"a_wait_bcon",
48 	"a_host",
49 	"a_suspend",
50 	"a_peripheral",
51 	"a_wait_vfall",
52 	"a_vbus_err"
53 };
54 
55 static int mv_otg_set_vbus(struct usb_otg *otg, bool on)
56 {
57 	struct mv_otg *mvotg = container_of(otg->usb_phy, struct mv_otg, phy);
58 	if (mvotg->pdata->set_vbus == NULL)
59 		return -ENODEV;
60 
61 	return mvotg->pdata->set_vbus(on);
62 }
63 
64 static int mv_otg_set_host(struct usb_otg *otg,
65 			   struct usb_bus *host)
66 {
67 	otg->host = host;
68 
69 	return 0;
70 }
71 
72 static int mv_otg_set_peripheral(struct usb_otg *otg,
73 				 struct usb_gadget *gadget)
74 {
75 	otg->gadget = gadget;
76 
77 	return 0;
78 }
79 
80 static void mv_otg_run_state_machine(struct mv_otg *mvotg,
81 				     unsigned long delay)
82 {
83 	dev_dbg(&mvotg->pdev->dev, "transceiver is updated\n");
84 	if (!mvotg->qwork)
85 		return;
86 
87 	queue_delayed_work(mvotg->qwork, &mvotg->work, delay);
88 }
89 
90 static void mv_otg_timer_await_bcon(unsigned long data)
91 {
92 	struct mv_otg *mvotg = (struct mv_otg *) data;
93 
94 	mvotg->otg_ctrl.a_wait_bcon_timeout = 1;
95 
96 	dev_info(&mvotg->pdev->dev, "B Device No Response!\n");
97 
98 	if (spin_trylock(&mvotg->wq_lock)) {
99 		mv_otg_run_state_machine(mvotg, 0);
100 		spin_unlock(&mvotg->wq_lock);
101 	}
102 }
103 
104 static int mv_otg_cancel_timer(struct mv_otg *mvotg, unsigned int id)
105 {
106 	struct timer_list *timer;
107 
108 	if (id >= OTG_TIMER_NUM)
109 		return -EINVAL;
110 
111 	timer = &mvotg->otg_ctrl.timer[id];
112 
113 	if (timer_pending(timer))
114 		del_timer(timer);
115 
116 	return 0;
117 }
118 
119 static int mv_otg_set_timer(struct mv_otg *mvotg, unsigned int id,
120 			    unsigned long interval,
121 			    void (*callback) (unsigned long))
122 {
123 	struct timer_list *timer;
124 
125 	if (id >= OTG_TIMER_NUM)
126 		return -EINVAL;
127 
128 	timer = &mvotg->otg_ctrl.timer[id];
129 	if (timer_pending(timer)) {
130 		dev_err(&mvotg->pdev->dev, "Timer%d is already running\n", id);
131 		return -EBUSY;
132 	}
133 
134 	init_timer(timer);
135 	timer->data = (unsigned long) mvotg;
136 	timer->function = callback;
137 	timer->expires = jiffies + interval;
138 	add_timer(timer);
139 
140 	return 0;
141 }
142 
143 static int mv_otg_reset(struct mv_otg *mvotg)
144 {
145 	unsigned int loops;
146 	u32 tmp;
147 
148 	/* Stop the controller */
149 	tmp = readl(&mvotg->op_regs->usbcmd);
150 	tmp &= ~USBCMD_RUN_STOP;
151 	writel(tmp, &mvotg->op_regs->usbcmd);
152 
153 	/* Reset the controller to get default values */
154 	writel(USBCMD_CTRL_RESET, &mvotg->op_regs->usbcmd);
155 
156 	loops = 500;
157 	while (readl(&mvotg->op_regs->usbcmd) & USBCMD_CTRL_RESET) {
158 		if (loops == 0) {
159 			dev_err(&mvotg->pdev->dev,
160 				"Wait for RESET completed TIMEOUT\n");
161 			return -ETIMEDOUT;
162 		}
163 		loops--;
164 		udelay(20);
165 	}
166 
167 	writel(0x0, &mvotg->op_regs->usbintr);
168 	tmp = readl(&mvotg->op_regs->usbsts);
169 	writel(tmp, &mvotg->op_regs->usbsts);
170 
171 	return 0;
172 }
173 
174 static void mv_otg_init_irq(struct mv_otg *mvotg)
175 {
176 	u32 otgsc;
177 
178 	mvotg->irq_en = OTGSC_INTR_A_SESSION_VALID
179 	    | OTGSC_INTR_A_VBUS_VALID;
180 	mvotg->irq_status = OTGSC_INTSTS_A_SESSION_VALID
181 	    | OTGSC_INTSTS_A_VBUS_VALID;
182 
183 	if (mvotg->pdata->vbus == NULL) {
184 		mvotg->irq_en |= OTGSC_INTR_B_SESSION_VALID
185 		    | OTGSC_INTR_B_SESSION_END;
186 		mvotg->irq_status |= OTGSC_INTSTS_B_SESSION_VALID
187 		    | OTGSC_INTSTS_B_SESSION_END;
188 	}
189 
190 	if (mvotg->pdata->id == NULL) {
191 		mvotg->irq_en |= OTGSC_INTR_USB_ID;
192 		mvotg->irq_status |= OTGSC_INTSTS_USB_ID;
193 	}
194 
195 	otgsc = readl(&mvotg->op_regs->otgsc);
196 	otgsc |= mvotg->irq_en;
197 	writel(otgsc, &mvotg->op_regs->otgsc);
198 }
199 
200 static void mv_otg_start_host(struct mv_otg *mvotg, int on)
201 {
202 #ifdef CONFIG_USB
203 	struct usb_otg *otg = mvotg->phy.otg;
204 	struct usb_hcd *hcd;
205 
206 	if (!otg->host)
207 		return;
208 
209 	dev_info(&mvotg->pdev->dev, "%s host\n", on ? "start" : "stop");
210 
211 	hcd = bus_to_hcd(otg->host);
212 
213 	if (on) {
214 		usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
215 		device_wakeup_enable(hcd->self.controller);
216 	} else {
217 		usb_remove_hcd(hcd);
218 	}
219 #endif /* CONFIG_USB */
220 }
221 
222 static void mv_otg_start_periphrals(struct mv_otg *mvotg, int on)
223 {
224 	struct usb_otg *otg = mvotg->phy.otg;
225 
226 	if (!otg->gadget)
227 		return;
228 
229 	dev_info(mvotg->phy.dev, "gadget %s\n", on ? "on" : "off");
230 
231 	if (on)
232 		usb_gadget_vbus_connect(otg->gadget);
233 	else
234 		usb_gadget_vbus_disconnect(otg->gadget);
235 }
236 
237 static void otg_clock_enable(struct mv_otg *mvotg)
238 {
239 	clk_prepare_enable(mvotg->clk);
240 }
241 
242 static void otg_clock_disable(struct mv_otg *mvotg)
243 {
244 	clk_disable_unprepare(mvotg->clk);
245 }
246 
247 static int mv_otg_enable_internal(struct mv_otg *mvotg)
248 {
249 	int retval = 0;
250 
251 	if (mvotg->active)
252 		return 0;
253 
254 	dev_dbg(&mvotg->pdev->dev, "otg enabled\n");
255 
256 	otg_clock_enable(mvotg);
257 	if (mvotg->pdata->phy_init) {
258 		retval = mvotg->pdata->phy_init(mvotg->phy_regs);
259 		if (retval) {
260 			dev_err(&mvotg->pdev->dev,
261 				"init phy error %d\n", retval);
262 			otg_clock_disable(mvotg);
263 			return retval;
264 		}
265 	}
266 	mvotg->active = 1;
267 
268 	return 0;
269 
270 }
271 
272 static int mv_otg_enable(struct mv_otg *mvotg)
273 {
274 	if (mvotg->clock_gating)
275 		return mv_otg_enable_internal(mvotg);
276 
277 	return 0;
278 }
279 
280 static void mv_otg_disable_internal(struct mv_otg *mvotg)
281 {
282 	if (mvotg->active) {
283 		dev_dbg(&mvotg->pdev->dev, "otg disabled\n");
284 		if (mvotg->pdata->phy_deinit)
285 			mvotg->pdata->phy_deinit(mvotg->phy_regs);
286 		otg_clock_disable(mvotg);
287 		mvotg->active = 0;
288 	}
289 }
290 
291 static void mv_otg_disable(struct mv_otg *mvotg)
292 {
293 	if (mvotg->clock_gating)
294 		mv_otg_disable_internal(mvotg);
295 }
296 
297 static void mv_otg_update_inputs(struct mv_otg *mvotg)
298 {
299 	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
300 	u32 otgsc;
301 
302 	otgsc = readl(&mvotg->op_regs->otgsc);
303 
304 	if (mvotg->pdata->vbus) {
305 		if (mvotg->pdata->vbus->poll() == VBUS_HIGH) {
306 			otg_ctrl->b_sess_vld = 1;
307 			otg_ctrl->b_sess_end = 0;
308 		} else {
309 			otg_ctrl->b_sess_vld = 0;
310 			otg_ctrl->b_sess_end = 1;
311 		}
312 	} else {
313 		otg_ctrl->b_sess_vld = !!(otgsc & OTGSC_STS_B_SESSION_VALID);
314 		otg_ctrl->b_sess_end = !!(otgsc & OTGSC_STS_B_SESSION_END);
315 	}
316 
317 	if (mvotg->pdata->id)
318 		otg_ctrl->id = !!mvotg->pdata->id->poll();
319 	else
320 		otg_ctrl->id = !!(otgsc & OTGSC_STS_USB_ID);
321 
322 	if (mvotg->pdata->otg_force_a_bus_req && !otg_ctrl->id)
323 		otg_ctrl->a_bus_req = 1;
324 
325 	otg_ctrl->a_sess_vld = !!(otgsc & OTGSC_STS_A_SESSION_VALID);
326 	otg_ctrl->a_vbus_vld = !!(otgsc & OTGSC_STS_A_VBUS_VALID);
327 
328 	dev_dbg(&mvotg->pdev->dev, "%s: ", __func__);
329 	dev_dbg(&mvotg->pdev->dev, "id %d\n", otg_ctrl->id);
330 	dev_dbg(&mvotg->pdev->dev, "b_sess_vld %d\n", otg_ctrl->b_sess_vld);
331 	dev_dbg(&mvotg->pdev->dev, "b_sess_end %d\n", otg_ctrl->b_sess_end);
332 	dev_dbg(&mvotg->pdev->dev, "a_vbus_vld %d\n", otg_ctrl->a_vbus_vld);
333 	dev_dbg(&mvotg->pdev->dev, "a_sess_vld %d\n", otg_ctrl->a_sess_vld);
334 }
335 
336 static void mv_otg_update_state(struct mv_otg *mvotg)
337 {
338 	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
339 	int old_state = mvotg->phy.otg->state;
340 
341 	switch (old_state) {
342 	case OTG_STATE_UNDEFINED:
343 		mvotg->phy.otg->state = OTG_STATE_B_IDLE;
344 		/* FALL THROUGH */
345 	case OTG_STATE_B_IDLE:
346 		if (otg_ctrl->id == 0)
347 			mvotg->phy.otg->state = OTG_STATE_A_IDLE;
348 		else if (otg_ctrl->b_sess_vld)
349 			mvotg->phy.otg->state = OTG_STATE_B_PERIPHERAL;
350 		break;
351 	case OTG_STATE_B_PERIPHERAL:
352 		if (!otg_ctrl->b_sess_vld || otg_ctrl->id == 0)
353 			mvotg->phy.otg->state = OTG_STATE_B_IDLE;
354 		break;
355 	case OTG_STATE_A_IDLE:
356 		if (otg_ctrl->id)
357 			mvotg->phy.otg->state = OTG_STATE_B_IDLE;
358 		else if (!(otg_ctrl->a_bus_drop) &&
359 			 (otg_ctrl->a_bus_req || otg_ctrl->a_srp_det))
360 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_VRISE;
361 		break;
362 	case OTG_STATE_A_WAIT_VRISE:
363 		if (otg_ctrl->a_vbus_vld)
364 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
365 		break;
366 	case OTG_STATE_A_WAIT_BCON:
367 		if (otg_ctrl->id || otg_ctrl->a_bus_drop
368 		    || otg_ctrl->a_wait_bcon_timeout) {
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_WAIT_VFALL;
372 			otg_ctrl->a_bus_req = 0;
373 		} else if (!otg_ctrl->a_vbus_vld) {
374 			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
375 			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
376 			mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
377 		} else if (otg_ctrl->b_conn) {
378 			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
379 			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
380 			mvotg->phy.otg->state = OTG_STATE_A_HOST;
381 		}
382 		break;
383 	case OTG_STATE_A_HOST:
384 		if (otg_ctrl->id || !otg_ctrl->b_conn
385 		    || otg_ctrl->a_bus_drop)
386 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
387 		else if (!otg_ctrl->a_vbus_vld)
388 			mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
389 		break;
390 	case OTG_STATE_A_WAIT_VFALL:
391 		if (otg_ctrl->id
392 		    || (!otg_ctrl->b_conn && otg_ctrl->a_sess_vld)
393 		    || otg_ctrl->a_bus_req)
394 			mvotg->phy.otg->state = OTG_STATE_A_IDLE;
395 		break;
396 	case OTG_STATE_A_VBUS_ERR:
397 		if (otg_ctrl->id || otg_ctrl->a_clr_err
398 		    || otg_ctrl->a_bus_drop) {
399 			otg_ctrl->a_clr_err = 0;
400 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_VFALL;
401 		}
402 		break;
403 	default:
404 		break;
405 	}
406 }
407 
408 static void mv_otg_work(struct work_struct *work)
409 {
410 	struct mv_otg *mvotg;
411 	struct usb_phy *phy;
412 	struct usb_otg *otg;
413 	int old_state;
414 
415 	mvotg = container_of(to_delayed_work(work), struct mv_otg, work);
416 
417 run:
418 	/* work queue is single thread, or we need spin_lock to protect */
419 	phy = &mvotg->phy;
420 	otg = mvotg->phy.otg;
421 	old_state = otg->state;
422 
423 	if (!mvotg->active)
424 		return;
425 
426 	mv_otg_update_inputs(mvotg);
427 	mv_otg_update_state(mvotg);
428 
429 	if (old_state != mvotg->phy.otg->state) {
430 		dev_info(&mvotg->pdev->dev, "change from state %s to %s\n",
431 			 state_string[old_state],
432 			 state_string[mvotg->phy.otg->state]);
433 
434 		switch (mvotg->phy.otg->state) {
435 		case OTG_STATE_B_IDLE:
436 			otg->default_a = 0;
437 			if (old_state == OTG_STATE_B_PERIPHERAL)
438 				mv_otg_start_periphrals(mvotg, 0);
439 			mv_otg_reset(mvotg);
440 			mv_otg_disable(mvotg);
441 			usb_phy_set_event(&mvotg->phy, USB_EVENT_NONE);
442 			break;
443 		case OTG_STATE_B_PERIPHERAL:
444 			mv_otg_enable(mvotg);
445 			mv_otg_start_periphrals(mvotg, 1);
446 			usb_phy_set_event(&mvotg->phy, USB_EVENT_ENUMERATED);
447 			break;
448 		case OTG_STATE_A_IDLE:
449 			otg->default_a = 1;
450 			mv_otg_enable(mvotg);
451 			if (old_state == OTG_STATE_A_WAIT_VFALL)
452 				mv_otg_start_host(mvotg, 0);
453 			mv_otg_reset(mvotg);
454 			break;
455 		case OTG_STATE_A_WAIT_VRISE:
456 			mv_otg_set_vbus(otg, 1);
457 			break;
458 		case OTG_STATE_A_WAIT_BCON:
459 			if (old_state != OTG_STATE_A_HOST)
460 				mv_otg_start_host(mvotg, 1);
461 			mv_otg_set_timer(mvotg, A_WAIT_BCON_TIMER,
462 					 T_A_WAIT_BCON,
463 					 mv_otg_timer_await_bcon);
464 			/*
465 			 * Now, we directly enter A_HOST. So set b_conn = 1
466 			 * here. In fact, it need host driver to notify us.
467 			 */
468 			mvotg->otg_ctrl.b_conn = 1;
469 			break;
470 		case OTG_STATE_A_HOST:
471 			break;
472 		case OTG_STATE_A_WAIT_VFALL:
473 			/*
474 			 * Now, we has exited A_HOST. So set b_conn = 0
475 			 * here. In fact, it need host driver to notify us.
476 			 */
477 			mvotg->otg_ctrl.b_conn = 0;
478 			mv_otg_set_vbus(otg, 0);
479 			break;
480 		case OTG_STATE_A_VBUS_ERR:
481 			break;
482 		default:
483 			break;
484 		}
485 		goto run;
486 	}
487 }
488 
489 static irqreturn_t mv_otg_irq(int irq, void *dev)
490 {
491 	struct mv_otg *mvotg = dev;
492 	u32 otgsc;
493 
494 	otgsc = readl(&mvotg->op_regs->otgsc);
495 	writel(otgsc, &mvotg->op_regs->otgsc);
496 
497 	/*
498 	 * if we have vbus, then the vbus detection for B-device
499 	 * will be done by mv_otg_inputs_irq().
500 	 */
501 	if (mvotg->pdata->vbus)
502 		if ((otgsc & OTGSC_STS_USB_ID) &&
503 		    !(otgsc & OTGSC_INTSTS_USB_ID))
504 			return IRQ_NONE;
505 
506 	if ((otgsc & mvotg->irq_status) == 0)
507 		return IRQ_NONE;
508 
509 	mv_otg_run_state_machine(mvotg, 0);
510 
511 	return IRQ_HANDLED;
512 }
513 
514 static irqreturn_t mv_otg_inputs_irq(int irq, void *dev)
515 {
516 	struct mv_otg *mvotg = dev;
517 
518 	/* The clock may disabled at this time */
519 	if (!mvotg->active) {
520 		mv_otg_enable(mvotg);
521 		mv_otg_init_irq(mvotg);
522 	}
523 
524 	mv_otg_run_state_machine(mvotg, 0);
525 
526 	return IRQ_HANDLED;
527 }
528 
529 static ssize_t
530 get_a_bus_req(struct device *dev, struct device_attribute *attr, char *buf)
531 {
532 	struct mv_otg *mvotg = dev_get_drvdata(dev);
533 	return scnprintf(buf, PAGE_SIZE, "%d\n",
534 			 mvotg->otg_ctrl.a_bus_req);
535 }
536 
537 static ssize_t
538 set_a_bus_req(struct device *dev, struct device_attribute *attr,
539 	      const char *buf, size_t count)
540 {
541 	struct mv_otg *mvotg = dev_get_drvdata(dev);
542 
543 	if (count > 2)
544 		return -1;
545 
546 	/* We will use this interface to change to A device */
547 	if (mvotg->phy.otg->state != OTG_STATE_B_IDLE
548 	    && mvotg->phy.otg->state != OTG_STATE_A_IDLE)
549 		return -1;
550 
551 	/* The clock may disabled and we need to set irq for ID detected */
552 	mv_otg_enable(mvotg);
553 	mv_otg_init_irq(mvotg);
554 
555 	if (buf[0] == '1') {
556 		mvotg->otg_ctrl.a_bus_req = 1;
557 		mvotg->otg_ctrl.a_bus_drop = 0;
558 		dev_dbg(&mvotg->pdev->dev,
559 			"User request: a_bus_req = 1\n");
560 
561 		if (spin_trylock(&mvotg->wq_lock)) {
562 			mv_otg_run_state_machine(mvotg, 0);
563 			spin_unlock(&mvotg->wq_lock);
564 		}
565 	}
566 
567 	return count;
568 }
569 
570 static DEVICE_ATTR(a_bus_req, S_IRUGO | S_IWUSR, get_a_bus_req,
571 		   set_a_bus_req);
572 
573 static ssize_t
574 set_a_clr_err(struct device *dev, struct device_attribute *attr,
575 	      const char *buf, size_t count)
576 {
577 	struct mv_otg *mvotg = dev_get_drvdata(dev);
578 	if (!mvotg->phy.otg->default_a)
579 		return -1;
580 
581 	if (count > 2)
582 		return -1;
583 
584 	if (buf[0] == '1') {
585 		mvotg->otg_ctrl.a_clr_err = 1;
586 		dev_dbg(&mvotg->pdev->dev,
587 			"User request: a_clr_err = 1\n");
588 	}
589 
590 	if (spin_trylock(&mvotg->wq_lock)) {
591 		mv_otg_run_state_machine(mvotg, 0);
592 		spin_unlock(&mvotg->wq_lock);
593 	}
594 
595 	return count;
596 }
597 
598 static DEVICE_ATTR(a_clr_err, S_IWUSR, NULL, set_a_clr_err);
599 
600 static ssize_t
601 get_a_bus_drop(struct device *dev, struct device_attribute *attr,
602 	       char *buf)
603 {
604 	struct mv_otg *mvotg = dev_get_drvdata(dev);
605 	return scnprintf(buf, PAGE_SIZE, "%d\n",
606 			 mvotg->otg_ctrl.a_bus_drop);
607 }
608 
609 static ssize_t
610 set_a_bus_drop(struct device *dev, struct device_attribute *attr,
611 	       const char *buf, size_t count)
612 {
613 	struct mv_otg *mvotg = dev_get_drvdata(dev);
614 	if (!mvotg->phy.otg->default_a)
615 		return -1;
616 
617 	if (count > 2)
618 		return -1;
619 
620 	if (buf[0] == '0') {
621 		mvotg->otg_ctrl.a_bus_drop = 0;
622 		dev_dbg(&mvotg->pdev->dev,
623 			"User request: a_bus_drop = 0\n");
624 	} else if (buf[0] == '1') {
625 		mvotg->otg_ctrl.a_bus_drop = 1;
626 		mvotg->otg_ctrl.a_bus_req = 0;
627 		dev_dbg(&mvotg->pdev->dev,
628 			"User request: a_bus_drop = 1\n");
629 		dev_dbg(&mvotg->pdev->dev,
630 			"User request: and a_bus_req = 0\n");
631 	}
632 
633 	if (spin_trylock(&mvotg->wq_lock)) {
634 		mv_otg_run_state_machine(mvotg, 0);
635 		spin_unlock(&mvotg->wq_lock);
636 	}
637 
638 	return count;
639 }
640 
641 static DEVICE_ATTR(a_bus_drop, S_IRUGO | S_IWUSR,
642 		   get_a_bus_drop, set_a_bus_drop);
643 
644 static struct attribute *inputs_attrs[] = {
645 	&dev_attr_a_bus_req.attr,
646 	&dev_attr_a_clr_err.attr,
647 	&dev_attr_a_bus_drop.attr,
648 	NULL,
649 };
650 
651 static const struct attribute_group inputs_attr_group = {
652 	.name = "inputs",
653 	.attrs = inputs_attrs,
654 };
655 
656 static int mv_otg_remove(struct platform_device *pdev)
657 {
658 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
659 
660 	sysfs_remove_group(&mvotg->pdev->dev.kobj, &inputs_attr_group);
661 
662 	if (mvotg->qwork) {
663 		flush_workqueue(mvotg->qwork);
664 		destroy_workqueue(mvotg->qwork);
665 	}
666 
667 	mv_otg_disable(mvotg);
668 
669 	usb_remove_phy(&mvotg->phy);
670 
671 	return 0;
672 }
673 
674 static int mv_otg_probe(struct platform_device *pdev)
675 {
676 	struct mv_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
677 	struct mv_otg *mvotg;
678 	struct usb_otg *otg;
679 	struct resource *r;
680 	int retval = 0, i;
681 
682 	if (pdata == NULL) {
683 		dev_err(&pdev->dev, "failed to get platform data\n");
684 		return -ENODEV;
685 	}
686 
687 	mvotg = devm_kzalloc(&pdev->dev, sizeof(*mvotg), GFP_KERNEL);
688 	if (!mvotg)
689 		return -ENOMEM;
690 
691 	otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
692 	if (!otg)
693 		return -ENOMEM;
694 
695 	platform_set_drvdata(pdev, mvotg);
696 
697 	mvotg->pdev = pdev;
698 	mvotg->pdata = pdata;
699 
700 	mvotg->clk = devm_clk_get(&pdev->dev, NULL);
701 	if (IS_ERR(mvotg->clk))
702 		return PTR_ERR(mvotg->clk);
703 
704 	mvotg->qwork = create_singlethread_workqueue("mv_otg_queue");
705 	if (!mvotg->qwork) {
706 		dev_dbg(&pdev->dev, "cannot create workqueue for OTG\n");
707 		return -ENOMEM;
708 	}
709 
710 	INIT_DELAYED_WORK(&mvotg->work, mv_otg_work);
711 
712 	/* OTG common part */
713 	mvotg->pdev = pdev;
714 	mvotg->phy.dev = &pdev->dev;
715 	mvotg->phy.otg = otg;
716 	mvotg->phy.label = driver_name;
717 
718 	otg->state = OTG_STATE_UNDEFINED;
719 	otg->usb_phy = &mvotg->phy;
720 	otg->set_host = mv_otg_set_host;
721 	otg->set_peripheral = mv_otg_set_peripheral;
722 	otg->set_vbus = mv_otg_set_vbus;
723 
724 	for (i = 0; i < OTG_TIMER_NUM; i++)
725 		init_timer(&mvotg->otg_ctrl.timer[i]);
726 
727 	r = platform_get_resource_byname(mvotg->pdev,
728 					 IORESOURCE_MEM, "phyregs");
729 	if (r == NULL) {
730 		dev_err(&pdev->dev, "no phy I/O memory resource defined\n");
731 		retval = -ENODEV;
732 		goto err_destroy_workqueue;
733 	}
734 
735 	mvotg->phy_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
736 	if (mvotg->phy_regs == NULL) {
737 		dev_err(&pdev->dev, "failed to map phy I/O memory\n");
738 		retval = -EFAULT;
739 		goto err_destroy_workqueue;
740 	}
741 
742 	r = platform_get_resource_byname(mvotg->pdev,
743 					 IORESOURCE_MEM, "capregs");
744 	if (r == NULL) {
745 		dev_err(&pdev->dev, "no I/O memory resource defined\n");
746 		retval = -ENODEV;
747 		goto err_destroy_workqueue;
748 	}
749 
750 	mvotg->cap_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
751 	if (mvotg->cap_regs == NULL) {
752 		dev_err(&pdev->dev, "failed to map I/O memory\n");
753 		retval = -EFAULT;
754 		goto err_destroy_workqueue;
755 	}
756 
757 	/* we will acces controller register, so enable the udc controller */
758 	retval = mv_otg_enable_internal(mvotg);
759 	if (retval) {
760 		dev_err(&pdev->dev, "mv otg enable error %d\n", retval);
761 		goto err_destroy_workqueue;
762 	}
763 
764 	mvotg->op_regs =
765 		(struct mv_otg_regs __iomem *) ((unsigned long) mvotg->cap_regs
766 			+ (readl(mvotg->cap_regs) & CAPLENGTH_MASK));
767 
768 	if (pdata->id) {
769 		retval = devm_request_threaded_irq(&pdev->dev, pdata->id->irq,
770 						NULL, mv_otg_inputs_irq,
771 						IRQF_ONESHOT, "id", mvotg);
772 		if (retval) {
773 			dev_info(&pdev->dev,
774 				 "Failed to request irq for ID\n");
775 			pdata->id = NULL;
776 		}
777 	}
778 
779 	if (pdata->vbus) {
780 		mvotg->clock_gating = 1;
781 		retval = devm_request_threaded_irq(&pdev->dev, pdata->vbus->irq,
782 						NULL, mv_otg_inputs_irq,
783 						IRQF_ONESHOT, "vbus", mvotg);
784 		if (retval) {
785 			dev_info(&pdev->dev,
786 				 "Failed to request irq for VBUS, "
787 				 "disable clock gating\n");
788 			mvotg->clock_gating = 0;
789 			pdata->vbus = NULL;
790 		}
791 	}
792 
793 	if (pdata->disable_otg_clock_gating)
794 		mvotg->clock_gating = 0;
795 
796 	mv_otg_reset(mvotg);
797 	mv_otg_init_irq(mvotg);
798 
799 	r = platform_get_resource(mvotg->pdev, IORESOURCE_IRQ, 0);
800 	if (r == NULL) {
801 		dev_err(&pdev->dev, "no IRQ resource defined\n");
802 		retval = -ENODEV;
803 		goto err_disable_clk;
804 	}
805 
806 	mvotg->irq = r->start;
807 	if (devm_request_irq(&pdev->dev, mvotg->irq, mv_otg_irq, IRQF_SHARED,
808 			driver_name, mvotg)) {
809 		dev_err(&pdev->dev, "Request irq %d for OTG failed\n",
810 			mvotg->irq);
811 		mvotg->irq = 0;
812 		retval = -ENODEV;
813 		goto err_disable_clk;
814 	}
815 
816 	retval = usb_add_phy(&mvotg->phy, USB_PHY_TYPE_USB2);
817 	if (retval < 0) {
818 		dev_err(&pdev->dev, "can't register transceiver, %d\n",
819 			retval);
820 		goto err_disable_clk;
821 	}
822 
823 	retval = sysfs_create_group(&pdev->dev.kobj, &inputs_attr_group);
824 	if (retval < 0) {
825 		dev_dbg(&pdev->dev,
826 			"Can't register sysfs attr group: %d\n", retval);
827 		goto err_remove_phy;
828 	}
829 
830 	spin_lock_init(&mvotg->wq_lock);
831 	if (spin_trylock(&mvotg->wq_lock)) {
832 		mv_otg_run_state_machine(mvotg, 2 * HZ);
833 		spin_unlock(&mvotg->wq_lock);
834 	}
835 
836 	dev_info(&pdev->dev,
837 		 "successful probe OTG device %s clock gating.\n",
838 		 mvotg->clock_gating ? "with" : "without");
839 
840 	return 0;
841 
842 err_remove_phy:
843 	usb_remove_phy(&mvotg->phy);
844 err_disable_clk:
845 	mv_otg_disable_internal(mvotg);
846 err_destroy_workqueue:
847 	flush_workqueue(mvotg->qwork);
848 	destroy_workqueue(mvotg->qwork);
849 
850 	return retval;
851 }
852 
853 #ifdef CONFIG_PM
854 static int mv_otg_suspend(struct platform_device *pdev, pm_message_t state)
855 {
856 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
857 
858 	if (mvotg->phy.otg->state != OTG_STATE_B_IDLE) {
859 		dev_info(&pdev->dev,
860 			 "OTG state is not B_IDLE, it is %d!\n",
861 			 mvotg->phy.otg->state);
862 		return -EAGAIN;
863 	}
864 
865 	if (!mvotg->clock_gating)
866 		mv_otg_disable_internal(mvotg);
867 
868 	return 0;
869 }
870 
871 static int mv_otg_resume(struct platform_device *pdev)
872 {
873 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
874 	u32 otgsc;
875 
876 	if (!mvotg->clock_gating) {
877 		mv_otg_enable_internal(mvotg);
878 
879 		otgsc = readl(&mvotg->op_regs->otgsc);
880 		otgsc |= mvotg->irq_en;
881 		writel(otgsc, &mvotg->op_regs->otgsc);
882 
883 		if (spin_trylock(&mvotg->wq_lock)) {
884 			mv_otg_run_state_machine(mvotg, 0);
885 			spin_unlock(&mvotg->wq_lock);
886 		}
887 	}
888 	return 0;
889 }
890 #endif
891 
892 static struct platform_driver mv_otg_driver = {
893 	.probe = mv_otg_probe,
894 	.remove = mv_otg_remove,
895 	.driver = {
896 		   .name = driver_name,
897 		   },
898 #ifdef CONFIG_PM
899 	.suspend = mv_otg_suspend,
900 	.resume = mv_otg_resume,
901 #endif
902 };
903 module_platform_driver(mv_otg_driver);
904