xref: /linux/drivers/usb/phy/phy-mv-usb.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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/init.h>
15 #include <linux/io.h>
16 #include <linux/uaccess.h>
17 #include <linux/device.h>
18 #include <linux/proc_fs.h>
19 #include <linux/clk.h>
20 #include <linux/workqueue.h>
21 #include <linux/platform_device.h>
22 
23 #include <linux/usb.h>
24 #include <linux/usb/ch9.h>
25 #include <linux/usb/otg.h>
26 #include <linux/usb/gadget.h>
27 #include <linux/usb/hcd.h>
28 #include <linux/platform_data/mv_usb.h>
29 
30 #include "phy-mv-usb.h"
31 
32 #define	DRIVER_DESC	"Marvell USB OTG transceiver driver"
33 #define	DRIVER_VERSION	"Jan 20, 2010"
34 
35 MODULE_DESCRIPTION(DRIVER_DESC);
36 MODULE_VERSION(DRIVER_VERSION);
37 MODULE_LICENSE("GPL");
38 
39 static const char driver_name[] = "mv-otg";
40 
41 static char *state_string[] = {
42 	"undefined",
43 	"b_idle",
44 	"b_srp_init",
45 	"b_peripheral",
46 	"b_wait_acon",
47 	"b_host",
48 	"a_idle",
49 	"a_wait_vrise",
50 	"a_wait_bcon",
51 	"a_host",
52 	"a_suspend",
53 	"a_peripheral",
54 	"a_wait_vfall",
55 	"a_vbus_err"
56 };
57 
58 static int mv_otg_set_vbus(struct usb_otg *otg, bool on)
59 {
60 	struct mv_otg *mvotg = container_of(otg->phy, struct mv_otg, phy);
61 	if (mvotg->pdata->set_vbus == NULL)
62 		return -ENODEV;
63 
64 	return mvotg->pdata->set_vbus(on);
65 }
66 
67 static int mv_otg_set_host(struct usb_otg *otg,
68 			   struct usb_bus *host)
69 {
70 	otg->host = host;
71 
72 	return 0;
73 }
74 
75 static int mv_otg_set_peripheral(struct usb_otg *otg,
76 				 struct usb_gadget *gadget)
77 {
78 	otg->gadget = gadget;
79 
80 	return 0;
81 }
82 
83 static void mv_otg_run_state_machine(struct mv_otg *mvotg,
84 				     unsigned long delay)
85 {
86 	dev_dbg(&mvotg->pdev->dev, "transceiver is updated\n");
87 	if (!mvotg->qwork)
88 		return;
89 
90 	queue_delayed_work(mvotg->qwork, &mvotg->work, delay);
91 }
92 
93 static void mv_otg_timer_await_bcon(unsigned long data)
94 {
95 	struct mv_otg *mvotg = (struct mv_otg *) data;
96 
97 	mvotg->otg_ctrl.a_wait_bcon_timeout = 1;
98 
99 	dev_info(&mvotg->pdev->dev, "B Device No Response!\n");
100 
101 	if (spin_trylock(&mvotg->wq_lock)) {
102 		mv_otg_run_state_machine(mvotg, 0);
103 		spin_unlock(&mvotg->wq_lock);
104 	}
105 }
106 
107 static int mv_otg_cancel_timer(struct mv_otg *mvotg, unsigned int id)
108 {
109 	struct timer_list *timer;
110 
111 	if (id >= OTG_TIMER_NUM)
112 		return -EINVAL;
113 
114 	timer = &mvotg->otg_ctrl.timer[id];
115 
116 	if (timer_pending(timer))
117 		del_timer(timer);
118 
119 	return 0;
120 }
121 
122 static int mv_otg_set_timer(struct mv_otg *mvotg, unsigned int id,
123 			    unsigned long interval,
124 			    void (*callback) (unsigned long))
125 {
126 	struct timer_list *timer;
127 
128 	if (id >= OTG_TIMER_NUM)
129 		return -EINVAL;
130 
131 	timer = &mvotg->otg_ctrl.timer[id];
132 	if (timer_pending(timer)) {
133 		dev_err(&mvotg->pdev->dev, "Timer%d is already running\n", id);
134 		return -EBUSY;
135 	}
136 
137 	init_timer(timer);
138 	timer->data = (unsigned long) mvotg;
139 	timer->function = callback;
140 	timer->expires = jiffies + interval;
141 	add_timer(timer);
142 
143 	return 0;
144 }
145 
146 static int mv_otg_reset(struct mv_otg *mvotg)
147 {
148 	unsigned int loops;
149 	u32 tmp;
150 
151 	/* Stop the controller */
152 	tmp = readl(&mvotg->op_regs->usbcmd);
153 	tmp &= ~USBCMD_RUN_STOP;
154 	writel(tmp, &mvotg->op_regs->usbcmd);
155 
156 	/* Reset the controller to get default values */
157 	writel(USBCMD_CTRL_RESET, &mvotg->op_regs->usbcmd);
158 
159 	loops = 500;
160 	while (readl(&mvotg->op_regs->usbcmd) & USBCMD_CTRL_RESET) {
161 		if (loops == 0) {
162 			dev_err(&mvotg->pdev->dev,
163 				"Wait for RESET completed TIMEOUT\n");
164 			return -ETIMEDOUT;
165 		}
166 		loops--;
167 		udelay(20);
168 	}
169 
170 	writel(0x0, &mvotg->op_regs->usbintr);
171 	tmp = readl(&mvotg->op_regs->usbsts);
172 	writel(tmp, &mvotg->op_regs->usbsts);
173 
174 	return 0;
175 }
176 
177 static void mv_otg_init_irq(struct mv_otg *mvotg)
178 {
179 	u32 otgsc;
180 
181 	mvotg->irq_en = OTGSC_INTR_A_SESSION_VALID
182 	    | OTGSC_INTR_A_VBUS_VALID;
183 	mvotg->irq_status = OTGSC_INTSTS_A_SESSION_VALID
184 	    | OTGSC_INTSTS_A_VBUS_VALID;
185 
186 	if (mvotg->pdata->vbus == NULL) {
187 		mvotg->irq_en |= OTGSC_INTR_B_SESSION_VALID
188 		    | OTGSC_INTR_B_SESSION_END;
189 		mvotg->irq_status |= OTGSC_INTSTS_B_SESSION_VALID
190 		    | OTGSC_INTSTS_B_SESSION_END;
191 	}
192 
193 	if (mvotg->pdata->id == NULL) {
194 		mvotg->irq_en |= OTGSC_INTR_USB_ID;
195 		mvotg->irq_status |= OTGSC_INTSTS_USB_ID;
196 	}
197 
198 	otgsc = readl(&mvotg->op_regs->otgsc);
199 	otgsc |= mvotg->irq_en;
200 	writel(otgsc, &mvotg->op_regs->otgsc);
201 }
202 
203 static void mv_otg_start_host(struct mv_otg *mvotg, int on)
204 {
205 #ifdef CONFIG_USB
206 	struct usb_otg *otg = mvotg->phy.otg;
207 	struct usb_hcd *hcd;
208 
209 	if (!otg->host)
210 		return;
211 
212 	dev_info(&mvotg->pdev->dev, "%s host\n", on ? "start" : "stop");
213 
214 	hcd = bus_to_hcd(otg->host);
215 
216 	if (on)
217 		usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
218 	else
219 		usb_remove_hcd(hcd);
220 #endif /* CONFIG_USB */
221 }
222 
223 static void mv_otg_start_periphrals(struct mv_otg *mvotg, int on)
224 {
225 	struct usb_otg *otg = mvotg->phy.otg;
226 
227 	if (!otg->gadget)
228 		return;
229 
230 	dev_info(mvotg->phy.dev, "gadget %s\n", on ? "on" : "off");
231 
232 	if (on)
233 		usb_gadget_vbus_connect(otg->gadget);
234 	else
235 		usb_gadget_vbus_disconnect(otg->gadget);
236 }
237 
238 static void otg_clock_enable(struct mv_otg *mvotg)
239 {
240 	clk_prepare_enable(mvotg->clk);
241 }
242 
243 static void otg_clock_disable(struct mv_otg *mvotg)
244 {
245 	clk_disable_unprepare(mvotg->clk);
246 }
247 
248 static int mv_otg_enable_internal(struct mv_otg *mvotg)
249 {
250 	int retval = 0;
251 
252 	if (mvotg->active)
253 		return 0;
254 
255 	dev_dbg(&mvotg->pdev->dev, "otg enabled\n");
256 
257 	otg_clock_enable(mvotg);
258 	if (mvotg->pdata->phy_init) {
259 		retval = mvotg->pdata->phy_init(mvotg->phy_regs);
260 		if (retval) {
261 			dev_err(&mvotg->pdev->dev,
262 				"init phy error %d\n", retval);
263 			otg_clock_disable(mvotg);
264 			return retval;
265 		}
266 	}
267 	mvotg->active = 1;
268 
269 	return 0;
270 
271 }
272 
273 static int mv_otg_enable(struct mv_otg *mvotg)
274 {
275 	if (mvotg->clock_gating)
276 		return mv_otg_enable_internal(mvotg);
277 
278 	return 0;
279 }
280 
281 static void mv_otg_disable_internal(struct mv_otg *mvotg)
282 {
283 	if (mvotg->active) {
284 		dev_dbg(&mvotg->pdev->dev, "otg disabled\n");
285 		if (mvotg->pdata->phy_deinit)
286 			mvotg->pdata->phy_deinit(mvotg->phy_regs);
287 		otg_clock_disable(mvotg);
288 		mvotg->active = 0;
289 	}
290 }
291 
292 static void mv_otg_disable(struct mv_otg *mvotg)
293 {
294 	if (mvotg->clock_gating)
295 		mv_otg_disable_internal(mvotg);
296 }
297 
298 static void mv_otg_update_inputs(struct mv_otg *mvotg)
299 {
300 	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
301 	u32 otgsc;
302 
303 	otgsc = readl(&mvotg->op_regs->otgsc);
304 
305 	if (mvotg->pdata->vbus) {
306 		if (mvotg->pdata->vbus->poll() == VBUS_HIGH) {
307 			otg_ctrl->b_sess_vld = 1;
308 			otg_ctrl->b_sess_end = 0;
309 		} else {
310 			otg_ctrl->b_sess_vld = 0;
311 			otg_ctrl->b_sess_end = 1;
312 		}
313 	} else {
314 		otg_ctrl->b_sess_vld = !!(otgsc & OTGSC_STS_B_SESSION_VALID);
315 		otg_ctrl->b_sess_end = !!(otgsc & OTGSC_STS_B_SESSION_END);
316 	}
317 
318 	if (mvotg->pdata->id)
319 		otg_ctrl->id = !!mvotg->pdata->id->poll();
320 	else
321 		otg_ctrl->id = !!(otgsc & OTGSC_STS_USB_ID);
322 
323 	if (mvotg->pdata->otg_force_a_bus_req && !otg_ctrl->id)
324 		otg_ctrl->a_bus_req = 1;
325 
326 	otg_ctrl->a_sess_vld = !!(otgsc & OTGSC_STS_A_SESSION_VALID);
327 	otg_ctrl->a_vbus_vld = !!(otgsc & OTGSC_STS_A_VBUS_VALID);
328 
329 	dev_dbg(&mvotg->pdev->dev, "%s: ", __func__);
330 	dev_dbg(&mvotg->pdev->dev, "id %d\n", otg_ctrl->id);
331 	dev_dbg(&mvotg->pdev->dev, "b_sess_vld %d\n", otg_ctrl->b_sess_vld);
332 	dev_dbg(&mvotg->pdev->dev, "b_sess_end %d\n", otg_ctrl->b_sess_end);
333 	dev_dbg(&mvotg->pdev->dev, "a_vbus_vld %d\n", otg_ctrl->a_vbus_vld);
334 	dev_dbg(&mvotg->pdev->dev, "a_sess_vld %d\n", otg_ctrl->a_sess_vld);
335 }
336 
337 static void mv_otg_update_state(struct mv_otg *mvotg)
338 {
339 	struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
340 	struct usb_phy *phy = &mvotg->phy;
341 	int old_state = phy->state;
342 
343 	switch (old_state) {
344 	case OTG_STATE_UNDEFINED:
345 		phy->state = OTG_STATE_B_IDLE;
346 		/* FALL THROUGH */
347 	case OTG_STATE_B_IDLE:
348 		if (otg_ctrl->id == 0)
349 			phy->state = OTG_STATE_A_IDLE;
350 		else if (otg_ctrl->b_sess_vld)
351 			phy->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 			phy->state = OTG_STATE_B_IDLE;
356 		break;
357 	case OTG_STATE_A_IDLE:
358 		if (otg_ctrl->id)
359 			phy->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 			phy->state = OTG_STATE_A_WAIT_VRISE;
363 		break;
364 	case OTG_STATE_A_WAIT_VRISE:
365 		if (otg_ctrl->a_vbus_vld)
366 			phy->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 			phy->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 			phy->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 			phy->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 			phy->state = OTG_STATE_A_WAIT_BCON;
389 		else if (!otg_ctrl->a_vbus_vld)
390 			phy->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 			phy->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 			phy->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 = phy->otg;
423 	old_state = phy->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 != phy->state) {
432 		dev_info(&mvotg->pdev->dev, "change from state %s to %s\n",
433 			 state_string[old_state],
434 			 state_string[phy->state]);
435 
436 		switch (phy->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 			break;
444 		case OTG_STATE_B_PERIPHERAL:
445 			mv_otg_enable(mvotg);
446 			mv_otg_start_periphrals(mvotg, 1);
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.state != OTG_STATE_B_IDLE
548 	    && mvotg->phy.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 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 		dev_err(&pdev->dev, "failed to allocate memory!\n");
690 		return -ENOMEM;
691 	}
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 	mvotg->phy.state = OTG_STATE_UNDEFINED;
720 
721 	otg->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.state != OTG_STATE_B_IDLE) {
861 		dev_info(&pdev->dev,
862 			 "OTG state is not B_IDLE, it is %d!\n",
863 			 mvotg->phy.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 		   .owner = THIS_MODULE,
899 		   .name = driver_name,
900 		   },
901 #ifdef CONFIG_PM
902 	.suspend = mv_otg_suspend,
903 	.resume = mv_otg_resume,
904 #endif
905 };
906 module_platform_driver(mv_otg_driver);
907