xref: /openbmc/linux/drivers/usb/phy/phy-mv-usb.c (revision 94cdda6b)
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 #define	DRIVER_VERSION	"Jan 20, 2010"
33 
34 MODULE_DESCRIPTION(DRIVER_DESC);
35 MODULE_VERSION(DRIVER_VERSION);
36 MODULE_LICENSE("GPL");
37 
38 static const char driver_name[] = "mv-otg";
39 
40 static char *state_string[] = {
41 	"undefined",
42 	"b_idle",
43 	"b_srp_init",
44 	"b_peripheral",
45 	"b_wait_acon",
46 	"b_host",
47 	"a_idle",
48 	"a_wait_vrise",
49 	"a_wait_bcon",
50 	"a_host",
51 	"a_suspend",
52 	"a_peripheral",
53 	"a_wait_vfall",
54 	"a_vbus_err"
55 };
56 
57 static int mv_otg_set_vbus(struct usb_otg *otg, bool on)
58 {
59 	struct mv_otg *mvotg = container_of(otg->usb_phy, struct mv_otg, phy);
60 	if (mvotg->pdata->set_vbus == NULL)
61 		return -ENODEV;
62 
63 	return mvotg->pdata->set_vbus(on);
64 }
65 
66 static int mv_otg_set_host(struct usb_otg *otg,
67 			   struct usb_bus *host)
68 {
69 	otg->host = host;
70 
71 	return 0;
72 }
73 
74 static int mv_otg_set_peripheral(struct usb_otg *otg,
75 				 struct usb_gadget *gadget)
76 {
77 	otg->gadget = gadget;
78 
79 	return 0;
80 }
81 
82 static void mv_otg_run_state_machine(struct mv_otg *mvotg,
83 				     unsigned long delay)
84 {
85 	dev_dbg(&mvotg->pdev->dev, "transceiver is updated\n");
86 	if (!mvotg->qwork)
87 		return;
88 
89 	queue_delayed_work(mvotg->qwork, &mvotg->work, delay);
90 }
91 
92 static void mv_otg_timer_await_bcon(unsigned long data)
93 {
94 	struct mv_otg *mvotg = (struct mv_otg *) data;
95 
96 	mvotg->otg_ctrl.a_wait_bcon_timeout = 1;
97 
98 	dev_info(&mvotg->pdev->dev, "B Device No Response!\n");
99 
100 	if (spin_trylock(&mvotg->wq_lock)) {
101 		mv_otg_run_state_machine(mvotg, 0);
102 		spin_unlock(&mvotg->wq_lock);
103 	}
104 }
105 
106 static int mv_otg_cancel_timer(struct mv_otg *mvotg, unsigned int id)
107 {
108 	struct timer_list *timer;
109 
110 	if (id >= OTG_TIMER_NUM)
111 		return -EINVAL;
112 
113 	timer = &mvotg->otg_ctrl.timer[id];
114 
115 	if (timer_pending(timer))
116 		del_timer(timer);
117 
118 	return 0;
119 }
120 
121 static int mv_otg_set_timer(struct mv_otg *mvotg, unsigned int id,
122 			    unsigned long interval,
123 			    void (*callback) (unsigned long))
124 {
125 	struct timer_list *timer;
126 
127 	if (id >= OTG_TIMER_NUM)
128 		return -EINVAL;
129 
130 	timer = &mvotg->otg_ctrl.timer[id];
131 	if (timer_pending(timer)) {
132 		dev_err(&mvotg->pdev->dev, "Timer%d is already running\n", id);
133 		return -EBUSY;
134 	}
135 
136 	init_timer(timer);
137 	timer->data = (unsigned long) mvotg;
138 	timer->function = callback;
139 	timer->expires = jiffies + interval;
140 	add_timer(timer);
141 
142 	return 0;
143 }
144 
145 static int mv_otg_reset(struct mv_otg *mvotg)
146 {
147 	unsigned int loops;
148 	u32 tmp;
149 
150 	/* Stop the controller */
151 	tmp = readl(&mvotg->op_regs->usbcmd);
152 	tmp &= ~USBCMD_RUN_STOP;
153 	writel(tmp, &mvotg->op_regs->usbcmd);
154 
155 	/* Reset the controller to get default values */
156 	writel(USBCMD_CTRL_RESET, &mvotg->op_regs->usbcmd);
157 
158 	loops = 500;
159 	while (readl(&mvotg->op_regs->usbcmd) & USBCMD_CTRL_RESET) {
160 		if (loops == 0) {
161 			dev_err(&mvotg->pdev->dev,
162 				"Wait for RESET completed TIMEOUT\n");
163 			return -ETIMEDOUT;
164 		}
165 		loops--;
166 		udelay(20);
167 	}
168 
169 	writel(0x0, &mvotg->op_regs->usbintr);
170 	tmp = readl(&mvotg->op_regs->usbsts);
171 	writel(tmp, &mvotg->op_regs->usbsts);
172 
173 	return 0;
174 }
175 
176 static void mv_otg_init_irq(struct mv_otg *mvotg)
177 {
178 	u32 otgsc;
179 
180 	mvotg->irq_en = OTGSC_INTR_A_SESSION_VALID
181 	    | OTGSC_INTR_A_VBUS_VALID;
182 	mvotg->irq_status = OTGSC_INTSTS_A_SESSION_VALID
183 	    | OTGSC_INTSTS_A_VBUS_VALID;
184 
185 	if (mvotg->pdata->vbus == NULL) {
186 		mvotg->irq_en |= OTGSC_INTR_B_SESSION_VALID
187 		    | OTGSC_INTR_B_SESSION_END;
188 		mvotg->irq_status |= OTGSC_INTSTS_B_SESSION_VALID
189 		    | OTGSC_INTSTS_B_SESSION_END;
190 	}
191 
192 	if (mvotg->pdata->id == NULL) {
193 		mvotg->irq_en |= OTGSC_INTR_USB_ID;
194 		mvotg->irq_status |= OTGSC_INTSTS_USB_ID;
195 	}
196 
197 	otgsc = readl(&mvotg->op_regs->otgsc);
198 	otgsc |= mvotg->irq_en;
199 	writel(otgsc, &mvotg->op_regs->otgsc);
200 }
201 
202 static void mv_otg_start_host(struct mv_otg *mvotg, int on)
203 {
204 #ifdef CONFIG_USB
205 	struct usb_otg *otg = mvotg->phy.otg;
206 	struct usb_hcd *hcd;
207 
208 	if (!otg->host)
209 		return;
210 
211 	dev_info(&mvotg->pdev->dev, "%s host\n", on ? "start" : "stop");
212 
213 	hcd = bus_to_hcd(otg->host);
214 
215 	if (on) {
216 		usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
217 		device_wakeup_enable(hcd->self.controller);
218 	} else {
219 		usb_remove_hcd(hcd);
220 	}
221 #endif /* CONFIG_USB */
222 }
223 
224 static void mv_otg_start_periphrals(struct mv_otg *mvotg, int on)
225 {
226 	struct usb_otg *otg = mvotg->phy.otg;
227 
228 	if (!otg->gadget)
229 		return;
230 
231 	dev_info(mvotg->phy.dev, "gadget %s\n", on ? "on" : "off");
232 
233 	if (on)
234 		usb_gadget_vbus_connect(otg->gadget);
235 	else
236 		usb_gadget_vbus_disconnect(otg->gadget);
237 }
238 
239 static void otg_clock_enable(struct mv_otg *mvotg)
240 {
241 	clk_prepare_enable(mvotg->clk);
242 }
243 
244 static void otg_clock_disable(struct mv_otg *mvotg)
245 {
246 	clk_disable_unprepare(mvotg->clk);
247 }
248 
249 static int mv_otg_enable_internal(struct mv_otg *mvotg)
250 {
251 	int retval = 0;
252 
253 	if (mvotg->active)
254 		return 0;
255 
256 	dev_dbg(&mvotg->pdev->dev, "otg enabled\n");
257 
258 	otg_clock_enable(mvotg);
259 	if (mvotg->pdata->phy_init) {
260 		retval = mvotg->pdata->phy_init(mvotg->phy_regs);
261 		if (retval) {
262 			dev_err(&mvotg->pdev->dev,
263 				"init phy error %d\n", retval);
264 			otg_clock_disable(mvotg);
265 			return retval;
266 		}
267 	}
268 	mvotg->active = 1;
269 
270 	return 0;
271 
272 }
273 
274 static int mv_otg_enable(struct mv_otg *mvotg)
275 {
276 	if (mvotg->clock_gating)
277 		return mv_otg_enable_internal(mvotg);
278 
279 	return 0;
280 }
281 
282 static void mv_otg_disable_internal(struct mv_otg *mvotg)
283 {
284 	if (mvotg->active) {
285 		dev_dbg(&mvotg->pdev->dev, "otg disabled\n");
286 		if (mvotg->pdata->phy_deinit)
287 			mvotg->pdata->phy_deinit(mvotg->phy_regs);
288 		otg_clock_disable(mvotg);
289 		mvotg->active = 0;
290 	}
291 }
292 
293 static void mv_otg_disable(struct mv_otg *mvotg)
294 {
295 	if (mvotg->clock_gating)
296 		mv_otg_disable_internal(mvotg);
297 }
298 
299 static void mv_otg_update_inputs(struct mv_otg *mvotg)
300 {
301 	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
302 	u32 otgsc;
303 
304 	otgsc = readl(&mvotg->op_regs->otgsc);
305 
306 	if (mvotg->pdata->vbus) {
307 		if (mvotg->pdata->vbus->poll() == VBUS_HIGH) {
308 			otg_ctrl->b_sess_vld = 1;
309 			otg_ctrl->b_sess_end = 0;
310 		} else {
311 			otg_ctrl->b_sess_vld = 0;
312 			otg_ctrl->b_sess_end = 1;
313 		}
314 	} else {
315 		otg_ctrl->b_sess_vld = !!(otgsc & OTGSC_STS_B_SESSION_VALID);
316 		otg_ctrl->b_sess_end = !!(otgsc & OTGSC_STS_B_SESSION_END);
317 	}
318 
319 	if (mvotg->pdata->id)
320 		otg_ctrl->id = !!mvotg->pdata->id->poll();
321 	else
322 		otg_ctrl->id = !!(otgsc & OTGSC_STS_USB_ID);
323 
324 	if (mvotg->pdata->otg_force_a_bus_req && !otg_ctrl->id)
325 		otg_ctrl->a_bus_req = 1;
326 
327 	otg_ctrl->a_sess_vld = !!(otgsc & OTGSC_STS_A_SESSION_VALID);
328 	otg_ctrl->a_vbus_vld = !!(otgsc & OTGSC_STS_A_VBUS_VALID);
329 
330 	dev_dbg(&mvotg->pdev->dev, "%s: ", __func__);
331 	dev_dbg(&mvotg->pdev->dev, "id %d\n", otg_ctrl->id);
332 	dev_dbg(&mvotg->pdev->dev, "b_sess_vld %d\n", otg_ctrl->b_sess_vld);
333 	dev_dbg(&mvotg->pdev->dev, "b_sess_end %d\n", otg_ctrl->b_sess_end);
334 	dev_dbg(&mvotg->pdev->dev, "a_vbus_vld %d\n", otg_ctrl->a_vbus_vld);
335 	dev_dbg(&mvotg->pdev->dev, "a_sess_vld %d\n", otg_ctrl->a_sess_vld);
336 }
337 
338 static void mv_otg_update_state(struct mv_otg *mvotg)
339 {
340 	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
341 	int old_state = mvotg->phy.otg->state;
342 
343 	switch (old_state) {
344 	case OTG_STATE_UNDEFINED:
345 		mvotg->phy.otg->state = OTG_STATE_B_IDLE;
346 		/* FALL THROUGH */
347 	case OTG_STATE_B_IDLE:
348 		if (otg_ctrl->id == 0)
349 			mvotg->phy.otg->state = OTG_STATE_A_IDLE;
350 		else if (otg_ctrl->b_sess_vld)
351 			mvotg->phy.otg->state = OTG_STATE_B_PERIPHERAL;
352 		break;
353 	case OTG_STATE_B_PERIPHERAL:
354 		if (!otg_ctrl->b_sess_vld || otg_ctrl->id == 0)
355 			mvotg->phy.otg->state = OTG_STATE_B_IDLE;
356 		break;
357 	case OTG_STATE_A_IDLE:
358 		if (otg_ctrl->id)
359 			mvotg->phy.otg->state = OTG_STATE_B_IDLE;
360 		else if (!(otg_ctrl->a_bus_drop) &&
361 			 (otg_ctrl->a_bus_req || otg_ctrl->a_srp_det))
362 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_VRISE;
363 		break;
364 	case OTG_STATE_A_WAIT_VRISE:
365 		if (otg_ctrl->a_vbus_vld)
366 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
367 		break;
368 	case OTG_STATE_A_WAIT_BCON:
369 		if (otg_ctrl->id || otg_ctrl->a_bus_drop
370 		    || otg_ctrl->a_wait_bcon_timeout) {
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_WAIT_VFALL;
374 			otg_ctrl->a_bus_req = 0;
375 		} else if (!otg_ctrl->a_vbus_vld) {
376 			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
377 			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
378 			mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
379 		} else if (otg_ctrl->b_conn) {
380 			mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
381 			mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
382 			mvotg->phy.otg->state = OTG_STATE_A_HOST;
383 		}
384 		break;
385 	case OTG_STATE_A_HOST:
386 		if (otg_ctrl->id || !otg_ctrl->b_conn
387 		    || otg_ctrl->a_bus_drop)
388 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
389 		else if (!otg_ctrl->a_vbus_vld)
390 			mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
391 		break;
392 	case OTG_STATE_A_WAIT_VFALL:
393 		if (otg_ctrl->id
394 		    || (!otg_ctrl->b_conn && otg_ctrl->a_sess_vld)
395 		    || otg_ctrl->a_bus_req)
396 			mvotg->phy.otg->state = OTG_STATE_A_IDLE;
397 		break;
398 	case OTG_STATE_A_VBUS_ERR:
399 		if (otg_ctrl->id || otg_ctrl->a_clr_err
400 		    || otg_ctrl->a_bus_drop) {
401 			otg_ctrl->a_clr_err = 0;
402 			mvotg->phy.otg->state = OTG_STATE_A_WAIT_VFALL;
403 		}
404 		break;
405 	default:
406 		break;
407 	}
408 }
409 
410 static void mv_otg_work(struct work_struct *work)
411 {
412 	struct mv_otg *mvotg;
413 	struct usb_phy *phy;
414 	struct usb_otg *otg;
415 	int old_state;
416 
417 	mvotg = container_of(to_delayed_work(work), struct mv_otg, work);
418 
419 run:
420 	/* work queue is single thread, or we need spin_lock to protect */
421 	phy = &mvotg->phy;
422 	otg = mvotg->phy.otg;
423 	old_state = otg->state;
424 
425 	if (!mvotg->active)
426 		return;
427 
428 	mv_otg_update_inputs(mvotg);
429 	mv_otg_update_state(mvotg);
430 
431 	if (old_state != mvotg->phy.otg->state) {
432 		dev_info(&mvotg->pdev->dev, "change from state %s to %s\n",
433 			 state_string[old_state],
434 			 state_string[mvotg->phy.otg->state]);
435 
436 		switch (mvotg->phy.otg->state) {
437 		case OTG_STATE_B_IDLE:
438 			otg->default_a = 0;
439 			if (old_state == OTG_STATE_B_PERIPHERAL)
440 				mv_otg_start_periphrals(mvotg, 0);
441 			mv_otg_reset(mvotg);
442 			mv_otg_disable(mvotg);
443 			usb_phy_set_event(&mvotg->phy, USB_EVENT_NONE);
444 			break;
445 		case OTG_STATE_B_PERIPHERAL:
446 			mv_otg_enable(mvotg);
447 			mv_otg_start_periphrals(mvotg, 1);
448 			usb_phy_set_event(&mvotg->phy, USB_EVENT_ENUMERATED);
449 			break;
450 		case OTG_STATE_A_IDLE:
451 			otg->default_a = 1;
452 			mv_otg_enable(mvotg);
453 			if (old_state == OTG_STATE_A_WAIT_VFALL)
454 				mv_otg_start_host(mvotg, 0);
455 			mv_otg_reset(mvotg);
456 			break;
457 		case OTG_STATE_A_WAIT_VRISE:
458 			mv_otg_set_vbus(otg, 1);
459 			break;
460 		case OTG_STATE_A_WAIT_BCON:
461 			if (old_state != OTG_STATE_A_HOST)
462 				mv_otg_start_host(mvotg, 1);
463 			mv_otg_set_timer(mvotg, A_WAIT_BCON_TIMER,
464 					 T_A_WAIT_BCON,
465 					 mv_otg_timer_await_bcon);
466 			/*
467 			 * Now, we directly enter A_HOST. So set b_conn = 1
468 			 * here. In fact, it need host driver to notify us.
469 			 */
470 			mvotg->otg_ctrl.b_conn = 1;
471 			break;
472 		case OTG_STATE_A_HOST:
473 			break;
474 		case OTG_STATE_A_WAIT_VFALL:
475 			/*
476 			 * Now, we has exited A_HOST. So set b_conn = 0
477 			 * here. In fact, it need host driver to notify us.
478 			 */
479 			mvotg->otg_ctrl.b_conn = 0;
480 			mv_otg_set_vbus(otg, 0);
481 			break;
482 		case OTG_STATE_A_VBUS_ERR:
483 			break;
484 		default:
485 			break;
486 		}
487 		goto run;
488 	}
489 }
490 
491 static irqreturn_t mv_otg_irq(int irq, void *dev)
492 {
493 	struct mv_otg *mvotg = dev;
494 	u32 otgsc;
495 
496 	otgsc = readl(&mvotg->op_regs->otgsc);
497 	writel(otgsc, &mvotg->op_regs->otgsc);
498 
499 	/*
500 	 * if we have vbus, then the vbus detection for B-device
501 	 * will be done by mv_otg_inputs_irq().
502 	 */
503 	if (mvotg->pdata->vbus)
504 		if ((otgsc & OTGSC_STS_USB_ID) &&
505 		    !(otgsc & OTGSC_INTSTS_USB_ID))
506 			return IRQ_NONE;
507 
508 	if ((otgsc & mvotg->irq_status) == 0)
509 		return IRQ_NONE;
510 
511 	mv_otg_run_state_machine(mvotg, 0);
512 
513 	return IRQ_HANDLED;
514 }
515 
516 static irqreturn_t mv_otg_inputs_irq(int irq, void *dev)
517 {
518 	struct mv_otg *mvotg = dev;
519 
520 	/* The clock may disabled at this time */
521 	if (!mvotg->active) {
522 		mv_otg_enable(mvotg);
523 		mv_otg_init_irq(mvotg);
524 	}
525 
526 	mv_otg_run_state_machine(mvotg, 0);
527 
528 	return IRQ_HANDLED;
529 }
530 
531 static ssize_t
532 get_a_bus_req(struct device *dev, struct device_attribute *attr, char *buf)
533 {
534 	struct mv_otg *mvotg = dev_get_drvdata(dev);
535 	return scnprintf(buf, PAGE_SIZE, "%d\n",
536 			 mvotg->otg_ctrl.a_bus_req);
537 }
538 
539 static ssize_t
540 set_a_bus_req(struct device *dev, struct device_attribute *attr,
541 	      const char *buf, size_t count)
542 {
543 	struct mv_otg *mvotg = dev_get_drvdata(dev);
544 
545 	if (count > 2)
546 		return -1;
547 
548 	/* We will use this interface to change to A device */
549 	if (mvotg->phy.otg->state != OTG_STATE_B_IDLE
550 	    && mvotg->phy.otg->state != OTG_STATE_A_IDLE)
551 		return -1;
552 
553 	/* The clock may disabled and we need to set irq for ID detected */
554 	mv_otg_enable(mvotg);
555 	mv_otg_init_irq(mvotg);
556 
557 	if (buf[0] == '1') {
558 		mvotg->otg_ctrl.a_bus_req = 1;
559 		mvotg->otg_ctrl.a_bus_drop = 0;
560 		dev_dbg(&mvotg->pdev->dev,
561 			"User request: a_bus_req = 1\n");
562 
563 		if (spin_trylock(&mvotg->wq_lock)) {
564 			mv_otg_run_state_machine(mvotg, 0);
565 			spin_unlock(&mvotg->wq_lock);
566 		}
567 	}
568 
569 	return count;
570 }
571 
572 static DEVICE_ATTR(a_bus_req, S_IRUGO | S_IWUSR, get_a_bus_req,
573 		   set_a_bus_req);
574 
575 static ssize_t
576 set_a_clr_err(struct device *dev, struct device_attribute *attr,
577 	      const char *buf, size_t count)
578 {
579 	struct mv_otg *mvotg = dev_get_drvdata(dev);
580 	if (!mvotg->phy.otg->default_a)
581 		return -1;
582 
583 	if (count > 2)
584 		return -1;
585 
586 	if (buf[0] == '1') {
587 		mvotg->otg_ctrl.a_clr_err = 1;
588 		dev_dbg(&mvotg->pdev->dev,
589 			"User request: a_clr_err = 1\n");
590 	}
591 
592 	if (spin_trylock(&mvotg->wq_lock)) {
593 		mv_otg_run_state_machine(mvotg, 0);
594 		spin_unlock(&mvotg->wq_lock);
595 	}
596 
597 	return count;
598 }
599 
600 static DEVICE_ATTR(a_clr_err, S_IWUSR, NULL, set_a_clr_err);
601 
602 static ssize_t
603 get_a_bus_drop(struct device *dev, struct device_attribute *attr,
604 	       char *buf)
605 {
606 	struct mv_otg *mvotg = dev_get_drvdata(dev);
607 	return scnprintf(buf, PAGE_SIZE, "%d\n",
608 			 mvotg->otg_ctrl.a_bus_drop);
609 }
610 
611 static ssize_t
612 set_a_bus_drop(struct device *dev, struct device_attribute *attr,
613 	       const char *buf, size_t count)
614 {
615 	struct mv_otg *mvotg = dev_get_drvdata(dev);
616 	if (!mvotg->phy.otg->default_a)
617 		return -1;
618 
619 	if (count > 2)
620 		return -1;
621 
622 	if (buf[0] == '0') {
623 		mvotg->otg_ctrl.a_bus_drop = 0;
624 		dev_dbg(&mvotg->pdev->dev,
625 			"User request: a_bus_drop = 0\n");
626 	} else if (buf[0] == '1') {
627 		mvotg->otg_ctrl.a_bus_drop = 1;
628 		mvotg->otg_ctrl.a_bus_req = 0;
629 		dev_dbg(&mvotg->pdev->dev,
630 			"User request: a_bus_drop = 1\n");
631 		dev_dbg(&mvotg->pdev->dev,
632 			"User request: and a_bus_req = 0\n");
633 	}
634 
635 	if (spin_trylock(&mvotg->wq_lock)) {
636 		mv_otg_run_state_machine(mvotg, 0);
637 		spin_unlock(&mvotg->wq_lock);
638 	}
639 
640 	return count;
641 }
642 
643 static DEVICE_ATTR(a_bus_drop, S_IRUGO | S_IWUSR,
644 		   get_a_bus_drop, set_a_bus_drop);
645 
646 static struct attribute *inputs_attrs[] = {
647 	&dev_attr_a_bus_req.attr,
648 	&dev_attr_a_clr_err.attr,
649 	&dev_attr_a_bus_drop.attr,
650 	NULL,
651 };
652 
653 static struct attribute_group inputs_attr_group = {
654 	.name = "inputs",
655 	.attrs = inputs_attrs,
656 };
657 
658 static int mv_otg_remove(struct platform_device *pdev)
659 {
660 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
661 
662 	sysfs_remove_group(&mvotg->pdev->dev.kobj, &inputs_attr_group);
663 
664 	if (mvotg->qwork) {
665 		flush_workqueue(mvotg->qwork);
666 		destroy_workqueue(mvotg->qwork);
667 	}
668 
669 	mv_otg_disable(mvotg);
670 
671 	usb_remove_phy(&mvotg->phy);
672 
673 	return 0;
674 }
675 
676 static int mv_otg_probe(struct platform_device *pdev)
677 {
678 	struct mv_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
679 	struct mv_otg *mvotg;
680 	struct usb_otg *otg;
681 	struct resource *r;
682 	int retval = 0, i;
683 
684 	if (pdata == NULL) {
685 		dev_err(&pdev->dev, "failed to get platform data\n");
686 		return -ENODEV;
687 	}
688 
689 	mvotg = devm_kzalloc(&pdev->dev, sizeof(*mvotg), GFP_KERNEL);
690 	if (!mvotg)
691 		return -ENOMEM;
692 
693 	otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
694 	if (!otg)
695 		return -ENOMEM;
696 
697 	platform_set_drvdata(pdev, mvotg);
698 
699 	mvotg->pdev = pdev;
700 	mvotg->pdata = pdata;
701 
702 	mvotg->clk = devm_clk_get(&pdev->dev, NULL);
703 	if (IS_ERR(mvotg->clk))
704 		return PTR_ERR(mvotg->clk);
705 
706 	mvotg->qwork = create_singlethread_workqueue("mv_otg_queue");
707 	if (!mvotg->qwork) {
708 		dev_dbg(&pdev->dev, "cannot create workqueue for OTG\n");
709 		return -ENOMEM;
710 	}
711 
712 	INIT_DELAYED_WORK(&mvotg->work, mv_otg_work);
713 
714 	/* OTG common part */
715 	mvotg->pdev = pdev;
716 	mvotg->phy.dev = &pdev->dev;
717 	mvotg->phy.otg = otg;
718 	mvotg->phy.label = driver_name;
719 
720 	otg->state = OTG_STATE_UNDEFINED;
721 	otg->usb_phy = &mvotg->phy;
722 	otg->set_host = mv_otg_set_host;
723 	otg->set_peripheral = mv_otg_set_peripheral;
724 	otg->set_vbus = mv_otg_set_vbus;
725 
726 	for (i = 0; i < OTG_TIMER_NUM; i++)
727 		init_timer(&mvotg->otg_ctrl.timer[i]);
728 
729 	r = platform_get_resource_byname(mvotg->pdev,
730 					 IORESOURCE_MEM, "phyregs");
731 	if (r == NULL) {
732 		dev_err(&pdev->dev, "no phy I/O memory resource defined\n");
733 		retval = -ENODEV;
734 		goto err_destroy_workqueue;
735 	}
736 
737 	mvotg->phy_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
738 	if (mvotg->phy_regs == NULL) {
739 		dev_err(&pdev->dev, "failed to map phy I/O memory\n");
740 		retval = -EFAULT;
741 		goto err_destroy_workqueue;
742 	}
743 
744 	r = platform_get_resource_byname(mvotg->pdev,
745 					 IORESOURCE_MEM, "capregs");
746 	if (r == NULL) {
747 		dev_err(&pdev->dev, "no I/O memory resource defined\n");
748 		retval = -ENODEV;
749 		goto err_destroy_workqueue;
750 	}
751 
752 	mvotg->cap_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
753 	if (mvotg->cap_regs == NULL) {
754 		dev_err(&pdev->dev, "failed to map I/O memory\n");
755 		retval = -EFAULT;
756 		goto err_destroy_workqueue;
757 	}
758 
759 	/* we will acces controller register, so enable the udc controller */
760 	retval = mv_otg_enable_internal(mvotg);
761 	if (retval) {
762 		dev_err(&pdev->dev, "mv otg enable error %d\n", retval);
763 		goto err_destroy_workqueue;
764 	}
765 
766 	mvotg->op_regs =
767 		(struct mv_otg_regs __iomem *) ((unsigned long) mvotg->cap_regs
768 			+ (readl(mvotg->cap_regs) & CAPLENGTH_MASK));
769 
770 	if (pdata->id) {
771 		retval = devm_request_threaded_irq(&pdev->dev, pdata->id->irq,
772 						NULL, mv_otg_inputs_irq,
773 						IRQF_ONESHOT, "id", mvotg);
774 		if (retval) {
775 			dev_info(&pdev->dev,
776 				 "Failed to request irq for ID\n");
777 			pdata->id = NULL;
778 		}
779 	}
780 
781 	if (pdata->vbus) {
782 		mvotg->clock_gating = 1;
783 		retval = devm_request_threaded_irq(&pdev->dev, pdata->vbus->irq,
784 						NULL, mv_otg_inputs_irq,
785 						IRQF_ONESHOT, "vbus", mvotg);
786 		if (retval) {
787 			dev_info(&pdev->dev,
788 				 "Failed to request irq for VBUS, "
789 				 "disable clock gating\n");
790 			mvotg->clock_gating = 0;
791 			pdata->vbus = NULL;
792 		}
793 	}
794 
795 	if (pdata->disable_otg_clock_gating)
796 		mvotg->clock_gating = 0;
797 
798 	mv_otg_reset(mvotg);
799 	mv_otg_init_irq(mvotg);
800 
801 	r = platform_get_resource(mvotg->pdev, IORESOURCE_IRQ, 0);
802 	if (r == NULL) {
803 		dev_err(&pdev->dev, "no IRQ resource defined\n");
804 		retval = -ENODEV;
805 		goto err_disable_clk;
806 	}
807 
808 	mvotg->irq = r->start;
809 	if (devm_request_irq(&pdev->dev, mvotg->irq, mv_otg_irq, IRQF_SHARED,
810 			driver_name, mvotg)) {
811 		dev_err(&pdev->dev, "Request irq %d for OTG failed\n",
812 			mvotg->irq);
813 		mvotg->irq = 0;
814 		retval = -ENODEV;
815 		goto err_disable_clk;
816 	}
817 
818 	retval = usb_add_phy(&mvotg->phy, USB_PHY_TYPE_USB2);
819 	if (retval < 0) {
820 		dev_err(&pdev->dev, "can't register transceiver, %d\n",
821 			retval);
822 		goto err_disable_clk;
823 	}
824 
825 	retval = sysfs_create_group(&pdev->dev.kobj, &inputs_attr_group);
826 	if (retval < 0) {
827 		dev_dbg(&pdev->dev,
828 			"Can't register sysfs attr group: %d\n", retval);
829 		goto err_remove_phy;
830 	}
831 
832 	spin_lock_init(&mvotg->wq_lock);
833 	if (spin_trylock(&mvotg->wq_lock)) {
834 		mv_otg_run_state_machine(mvotg, 2 * HZ);
835 		spin_unlock(&mvotg->wq_lock);
836 	}
837 
838 	dev_info(&pdev->dev,
839 		 "successful probe OTG device %s clock gating.\n",
840 		 mvotg->clock_gating ? "with" : "without");
841 
842 	return 0;
843 
844 err_remove_phy:
845 	usb_remove_phy(&mvotg->phy);
846 err_disable_clk:
847 	mv_otg_disable_internal(mvotg);
848 err_destroy_workqueue:
849 	flush_workqueue(mvotg->qwork);
850 	destroy_workqueue(mvotg->qwork);
851 
852 	return retval;
853 }
854 
855 #ifdef CONFIG_PM
856 static int mv_otg_suspend(struct platform_device *pdev, pm_message_t state)
857 {
858 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
859 
860 	if (mvotg->phy.otg->state != OTG_STATE_B_IDLE) {
861 		dev_info(&pdev->dev,
862 			 "OTG state is not B_IDLE, it is %d!\n",
863 			 mvotg->phy.otg->state);
864 		return -EAGAIN;
865 	}
866 
867 	if (!mvotg->clock_gating)
868 		mv_otg_disable_internal(mvotg);
869 
870 	return 0;
871 }
872 
873 static int mv_otg_resume(struct platform_device *pdev)
874 {
875 	struct mv_otg *mvotg = platform_get_drvdata(pdev);
876 	u32 otgsc;
877 
878 	if (!mvotg->clock_gating) {
879 		mv_otg_enable_internal(mvotg);
880 
881 		otgsc = readl(&mvotg->op_regs->otgsc);
882 		otgsc |= mvotg->irq_en;
883 		writel(otgsc, &mvotg->op_regs->otgsc);
884 
885 		if (spin_trylock(&mvotg->wq_lock)) {
886 			mv_otg_run_state_machine(mvotg, 0);
887 			spin_unlock(&mvotg->wq_lock);
888 		}
889 	}
890 	return 0;
891 }
892 #endif
893 
894 static struct platform_driver mv_otg_driver = {
895 	.probe = mv_otg_probe,
896 	.remove = mv_otg_remove,
897 	.driver = {
898 		   .name = driver_name,
899 		   },
900 #ifdef CONFIG_PM
901 	.suspend = mv_otg_suspend,
902 	.resume = mv_otg_resume,
903 #endif
904 };
905 module_platform_driver(mv_otg_driver);
906