xref: /openbmc/linux/drivers/usb/musb/musb_core.c (revision 1504b6f9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * MUSB OTG driver core code
4  *
5  * Copyright 2005 Mentor Graphics Corporation
6  * Copyright (C) 2005-2006 by Texas Instruments
7  * Copyright (C) 2006-2007 Nokia Corporation
8  */
9 
10 /*
11  * Inventra (Multipoint) Dual-Role Controller Driver for Linux.
12  *
13  * This consists of a Host Controller Driver (HCD) and a peripheral
14  * controller driver implementing the "Gadget" API; OTG support is
15  * in the works.  These are normal Linux-USB controller drivers which
16  * use IRQs and have no dedicated thread.
17  *
18  * This version of the driver has only been used with products from
19  * Texas Instruments.  Those products integrate the Inventra logic
20  * with other DMA, IRQ, and bus modules, as well as other logic that
21  * needs to be reflected in this driver.
22  *
23  *
24  * NOTE:  the original Mentor code here was pretty much a collection
25  * of mechanisms that don't seem to have been fully integrated/working
26  * for *any* Linux kernel version.  This version aims at Linux 2.6.now,
27  * Key open issues include:
28  *
29  *  - Lack of host-side transaction scheduling, for all transfer types.
30  *    The hardware doesn't do it; instead, software must.
31  *
32  *    This is not an issue for OTG devices that don't support external
33  *    hubs, but for more "normal" USB hosts it's a user issue that the
34  *    "multipoint" support doesn't scale in the expected ways.  That
35  *    includes DaVinci EVM in a common non-OTG mode.
36  *
37  *      * Control and bulk use dedicated endpoints, and there's as
38  *        yet no mechanism to either (a) reclaim the hardware when
39  *        peripherals are NAKing, which gets complicated with bulk
40  *        endpoints, or (b) use more than a single bulk endpoint in
41  *        each direction.
42  *
43  *        RESULT:  one device may be perceived as blocking another one.
44  *
45  *      * Interrupt and isochronous will dynamically allocate endpoint
46  *        hardware, but (a) there's no record keeping for bandwidth;
47  *        (b) in the common case that few endpoints are available, there
48  *        is no mechanism to reuse endpoints to talk to multiple devices.
49  *
50  *        RESULT:  At one extreme, bandwidth can be overcommitted in
51  *        some hardware configurations, no faults will be reported.
52  *        At the other extreme, the bandwidth capabilities which do
53  *        exist tend to be severely undercommitted.  You can't yet hook
54  *        up both a keyboard and a mouse to an external USB hub.
55  */
56 
57 /*
58  * This gets many kinds of configuration information:
59  *	- Kconfig for everything user-configurable
60  *	- platform_device for addressing, irq, and platform_data
61  *	- platform_data is mostly for board-specific information
62  *	  (plus recentrly, SOC or family details)
63  *
64  * Most of the conditional compilation will (someday) vanish.
65  */
66 
67 #include <linux/module.h>
68 #include <linux/kernel.h>
69 #include <linux/sched.h>
70 #include <linux/slab.h>
71 #include <linux/list.h>
72 #include <linux/kobject.h>
73 #include <linux/prefetch.h>
74 #include <linux/platform_device.h>
75 #include <linux/io.h>
76 #include <linux/iopoll.h>
77 #include <linux/dma-mapping.h>
78 #include <linux/usb.h>
79 #include <linux/usb/of.h>
80 
81 #include "musb_core.h"
82 #include "musb_trace.h"
83 
84 #define TA_WAIT_BCON(m) max_t(int, (m)->a_wait_bcon, OTG_TIME_A_WAIT_BCON)
85 
86 
87 #define DRIVER_AUTHOR "Mentor Graphics, Texas Instruments, Nokia"
88 #define DRIVER_DESC "Inventra Dual-Role USB Controller Driver"
89 
90 #define MUSB_VERSION "6.0"
91 
92 #define DRIVER_INFO DRIVER_DESC ", v" MUSB_VERSION
93 
94 #define MUSB_DRIVER_NAME "musb-hdrc"
95 const char musb_driver_name[] = MUSB_DRIVER_NAME;
96 
97 MODULE_DESCRIPTION(DRIVER_INFO);
98 MODULE_AUTHOR(DRIVER_AUTHOR);
99 MODULE_LICENSE("GPL");
100 MODULE_ALIAS("platform:" MUSB_DRIVER_NAME);
101 
102 
103 /*-------------------------------------------------------------------------*/
104 
105 static inline struct musb *dev_to_musb(struct device *dev)
106 {
107 	return dev_get_drvdata(dev);
108 }
109 
110 enum musb_mode musb_get_mode(struct device *dev)
111 {
112 	enum usb_dr_mode mode;
113 
114 	mode = usb_get_dr_mode(dev);
115 	switch (mode) {
116 	case USB_DR_MODE_HOST:
117 		return MUSB_HOST;
118 	case USB_DR_MODE_PERIPHERAL:
119 		return MUSB_PERIPHERAL;
120 	case USB_DR_MODE_OTG:
121 	case USB_DR_MODE_UNKNOWN:
122 	default:
123 		return MUSB_OTG;
124 	}
125 }
126 EXPORT_SYMBOL_GPL(musb_get_mode);
127 
128 /*-------------------------------------------------------------------------*/
129 
130 static int musb_ulpi_read(struct usb_phy *phy, u32 reg)
131 {
132 	void __iomem *addr = phy->io_priv;
133 	int	i = 0;
134 	u8	r;
135 	u8	power;
136 	int	ret;
137 
138 	pm_runtime_get_sync(phy->io_dev);
139 
140 	/* Make sure the transceiver is not in low power mode */
141 	power = musb_readb(addr, MUSB_POWER);
142 	power &= ~MUSB_POWER_SUSPENDM;
143 	musb_writeb(addr, MUSB_POWER, power);
144 
145 	/* REVISIT: musbhdrc_ulpi_an.pdf recommends setting the
146 	 * ULPICarKitControlDisableUTMI after clearing POWER_SUSPENDM.
147 	 */
148 
149 	musb_writeb(addr, MUSB_ULPI_REG_ADDR, (u8)reg);
150 	musb_writeb(addr, MUSB_ULPI_REG_CONTROL,
151 			MUSB_ULPI_REG_REQ | MUSB_ULPI_RDN_WR);
152 
153 	while (!(musb_readb(addr, MUSB_ULPI_REG_CONTROL)
154 				& MUSB_ULPI_REG_CMPLT)) {
155 		i++;
156 		if (i == 10000) {
157 			ret = -ETIMEDOUT;
158 			goto out;
159 		}
160 
161 	}
162 	r = musb_readb(addr, MUSB_ULPI_REG_CONTROL);
163 	r &= ~MUSB_ULPI_REG_CMPLT;
164 	musb_writeb(addr, MUSB_ULPI_REG_CONTROL, r);
165 
166 	ret = musb_readb(addr, MUSB_ULPI_REG_DATA);
167 
168 out:
169 	pm_runtime_put(phy->io_dev);
170 
171 	return ret;
172 }
173 
174 static int musb_ulpi_write(struct usb_phy *phy, u32 val, u32 reg)
175 {
176 	void __iomem *addr = phy->io_priv;
177 	int	i = 0;
178 	u8	r = 0;
179 	u8	power;
180 	int	ret = 0;
181 
182 	pm_runtime_get_sync(phy->io_dev);
183 
184 	/* Make sure the transceiver is not in low power mode */
185 	power = musb_readb(addr, MUSB_POWER);
186 	power &= ~MUSB_POWER_SUSPENDM;
187 	musb_writeb(addr, MUSB_POWER, power);
188 
189 	musb_writeb(addr, MUSB_ULPI_REG_ADDR, (u8)reg);
190 	musb_writeb(addr, MUSB_ULPI_REG_DATA, (u8)val);
191 	musb_writeb(addr, MUSB_ULPI_REG_CONTROL, MUSB_ULPI_REG_REQ);
192 
193 	while (!(musb_readb(addr, MUSB_ULPI_REG_CONTROL)
194 				& MUSB_ULPI_REG_CMPLT)) {
195 		i++;
196 		if (i == 10000) {
197 			ret = -ETIMEDOUT;
198 			goto out;
199 		}
200 	}
201 
202 	r = musb_readb(addr, MUSB_ULPI_REG_CONTROL);
203 	r &= ~MUSB_ULPI_REG_CMPLT;
204 	musb_writeb(addr, MUSB_ULPI_REG_CONTROL, r);
205 
206 out:
207 	pm_runtime_put(phy->io_dev);
208 
209 	return ret;
210 }
211 
212 static struct usb_phy_io_ops musb_ulpi_access = {
213 	.read = musb_ulpi_read,
214 	.write = musb_ulpi_write,
215 };
216 
217 /*-------------------------------------------------------------------------*/
218 
219 static u32 musb_default_fifo_offset(u8 epnum)
220 {
221 	return 0x20 + (epnum * 4);
222 }
223 
224 /* "flat" mapping: each endpoint has its own i/o address */
225 static void musb_flat_ep_select(void __iomem *mbase, u8 epnum)
226 {
227 }
228 
229 static u32 musb_flat_ep_offset(u8 epnum, u16 offset)
230 {
231 	return 0x100 + (0x10 * epnum) + offset;
232 }
233 
234 /* "indexed" mapping: INDEX register controls register bank select */
235 static void musb_indexed_ep_select(void __iomem *mbase, u8 epnum)
236 {
237 	musb_writeb(mbase, MUSB_INDEX, epnum);
238 }
239 
240 static u32 musb_indexed_ep_offset(u8 epnum, u16 offset)
241 {
242 	return 0x10 + offset;
243 }
244 
245 static u32 musb_default_busctl_offset(u8 epnum, u16 offset)
246 {
247 	return 0x80 + (0x08 * epnum) + offset;
248 }
249 
250 static u8 musb_default_readb(void __iomem *addr, u32 offset)
251 {
252 	u8 data =  __raw_readb(addr + offset);
253 
254 	trace_musb_readb(__builtin_return_address(0), addr, offset, data);
255 	return data;
256 }
257 
258 static void musb_default_writeb(void __iomem *addr, u32 offset, u8 data)
259 {
260 	trace_musb_writeb(__builtin_return_address(0), addr, offset, data);
261 	__raw_writeb(data, addr + offset);
262 }
263 
264 static u16 musb_default_readw(void __iomem *addr, u32 offset)
265 {
266 	u16 data = __raw_readw(addr + offset);
267 
268 	trace_musb_readw(__builtin_return_address(0), addr, offset, data);
269 	return data;
270 }
271 
272 static void musb_default_writew(void __iomem *addr, u32 offset, u16 data)
273 {
274 	trace_musb_writew(__builtin_return_address(0), addr, offset, data);
275 	__raw_writew(data, addr + offset);
276 }
277 
278 static u16 musb_default_get_toggle(struct musb_qh *qh, int is_out)
279 {
280 	void __iomem *epio = qh->hw_ep->regs;
281 	u16 csr;
282 
283 	if (is_out)
284 		csr = musb_readw(epio, MUSB_TXCSR) & MUSB_TXCSR_H_DATATOGGLE;
285 	else
286 		csr = musb_readw(epio, MUSB_RXCSR) & MUSB_RXCSR_H_DATATOGGLE;
287 
288 	return csr;
289 }
290 
291 static u16 musb_default_set_toggle(struct musb_qh *qh, int is_out,
292 				   struct urb *urb)
293 {
294 	u16 csr;
295 	u16 toggle;
296 
297 	toggle = usb_gettoggle(urb->dev, qh->epnum, is_out);
298 
299 	if (is_out)
300 		csr = toggle ? (MUSB_TXCSR_H_WR_DATATOGGLE
301 				| MUSB_TXCSR_H_DATATOGGLE)
302 				: MUSB_TXCSR_CLRDATATOG;
303 	else
304 		csr = toggle ? (MUSB_RXCSR_H_WR_DATATOGGLE
305 				| MUSB_RXCSR_H_DATATOGGLE) : 0;
306 
307 	return csr;
308 }
309 
310 /*
311  * Load an endpoint's FIFO
312  */
313 static void musb_default_write_fifo(struct musb_hw_ep *hw_ep, u16 len,
314 				    const u8 *src)
315 {
316 	struct musb *musb = hw_ep->musb;
317 	void __iomem *fifo = hw_ep->fifo;
318 
319 	if (unlikely(len == 0))
320 		return;
321 
322 	prefetch((u8 *)src);
323 
324 	dev_dbg(musb->controller, "%cX ep%d fifo %p count %d buf %p\n",
325 			'T', hw_ep->epnum, fifo, len, src);
326 
327 	/* we can't assume unaligned reads work */
328 	if (likely((0x01 & (unsigned long) src) == 0)) {
329 		u16	index = 0;
330 
331 		/* best case is 32bit-aligned source address */
332 		if ((0x02 & (unsigned long) src) == 0) {
333 			if (len >= 4) {
334 				iowrite32_rep(fifo, src + index, len >> 2);
335 				index += len & ~0x03;
336 			}
337 			if (len & 0x02) {
338 				__raw_writew(*(u16 *)&src[index], fifo);
339 				index += 2;
340 			}
341 		} else {
342 			if (len >= 2) {
343 				iowrite16_rep(fifo, src + index, len >> 1);
344 				index += len & ~0x01;
345 			}
346 		}
347 		if (len & 0x01)
348 			__raw_writeb(src[index], fifo);
349 	} else  {
350 		/* byte aligned */
351 		iowrite8_rep(fifo, src, len);
352 	}
353 }
354 
355 /*
356  * Unload an endpoint's FIFO
357  */
358 static void musb_default_read_fifo(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
359 {
360 	struct musb *musb = hw_ep->musb;
361 	void __iomem *fifo = hw_ep->fifo;
362 
363 	if (unlikely(len == 0))
364 		return;
365 
366 	dev_dbg(musb->controller, "%cX ep%d fifo %p count %d buf %p\n",
367 			'R', hw_ep->epnum, fifo, len, dst);
368 
369 	/* we can't assume unaligned writes work */
370 	if (likely((0x01 & (unsigned long) dst) == 0)) {
371 		u16	index = 0;
372 
373 		/* best case is 32bit-aligned destination address */
374 		if ((0x02 & (unsigned long) dst) == 0) {
375 			if (len >= 4) {
376 				ioread32_rep(fifo, dst, len >> 2);
377 				index = len & ~0x03;
378 			}
379 			if (len & 0x02) {
380 				*(u16 *)&dst[index] = __raw_readw(fifo);
381 				index += 2;
382 			}
383 		} else {
384 			if (len >= 2) {
385 				ioread16_rep(fifo, dst, len >> 1);
386 				index = len & ~0x01;
387 			}
388 		}
389 		if (len & 0x01)
390 			dst[index] = __raw_readb(fifo);
391 	} else  {
392 		/* byte aligned */
393 		ioread8_rep(fifo, dst, len);
394 	}
395 }
396 
397 /*
398  * Old style IO functions
399  */
400 u8 (*musb_readb)(void __iomem *addr, u32 offset);
401 EXPORT_SYMBOL_GPL(musb_readb);
402 
403 void (*musb_writeb)(void __iomem *addr, u32 offset, u8 data);
404 EXPORT_SYMBOL_GPL(musb_writeb);
405 
406 u8 (*musb_clearb)(void __iomem *addr, u32 offset);
407 EXPORT_SYMBOL_GPL(musb_clearb);
408 
409 u16 (*musb_readw)(void __iomem *addr, u32 offset);
410 EXPORT_SYMBOL_GPL(musb_readw);
411 
412 void (*musb_writew)(void __iomem *addr, u32 offset, u16 data);
413 EXPORT_SYMBOL_GPL(musb_writew);
414 
415 u16 (*musb_clearw)(void __iomem *addr, u32 offset);
416 EXPORT_SYMBOL_GPL(musb_clearw);
417 
418 u32 musb_readl(void __iomem *addr, u32 offset)
419 {
420 	u32 data = __raw_readl(addr + offset);
421 
422 	trace_musb_readl(__builtin_return_address(0), addr, offset, data);
423 	return data;
424 }
425 EXPORT_SYMBOL_GPL(musb_readl);
426 
427 void musb_writel(void __iomem *addr, u32 offset, u32 data)
428 {
429 	trace_musb_writel(__builtin_return_address(0), addr, offset, data);
430 	__raw_writel(data, addr + offset);
431 }
432 EXPORT_SYMBOL_GPL(musb_writel);
433 
434 #ifndef CONFIG_MUSB_PIO_ONLY
435 struct dma_controller *
436 (*musb_dma_controller_create)(struct musb *musb, void __iomem *base);
437 EXPORT_SYMBOL(musb_dma_controller_create);
438 
439 void (*musb_dma_controller_destroy)(struct dma_controller *c);
440 EXPORT_SYMBOL(musb_dma_controller_destroy);
441 #endif
442 
443 /*
444  * New style IO functions
445  */
446 void musb_read_fifo(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
447 {
448 	return hw_ep->musb->io.read_fifo(hw_ep, len, dst);
449 }
450 
451 void musb_write_fifo(struct musb_hw_ep *hw_ep, u16 len, const u8 *src)
452 {
453 	return hw_ep->musb->io.write_fifo(hw_ep, len, src);
454 }
455 
456 static u8 musb_read_devctl(struct musb *musb)
457 {
458 	return musb_readb(musb->mregs, MUSB_DEVCTL);
459 }
460 
461 /**
462  * musb_set_host - set and initialize host mode
463  * @musb: musb controller driver data
464  *
465  * At least some musb revisions need to enable devctl session bit in
466  * peripheral mode to switch to host mode. Initializes things to host
467  * mode and sets A_IDLE. SoC glue needs to advance state further
468  * based on phy provided VBUS state.
469  *
470  * Note that the SoC glue code may need to wait for musb to settle
471  * on enable before calling this to avoid babble.
472  */
473 int musb_set_host(struct musb *musb)
474 {
475 	int error = 0;
476 	u8 devctl;
477 
478 	if (!musb)
479 		return -EINVAL;
480 
481 	devctl = musb_read_devctl(musb);
482 	if (!(devctl & MUSB_DEVCTL_BDEVICE)) {
483 		trace_musb_state(musb, devctl, "Already in host mode");
484 		goto init_data;
485 	}
486 
487 	devctl |= MUSB_DEVCTL_SESSION;
488 	musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
489 
490 	error = readx_poll_timeout(musb_read_devctl, musb, devctl,
491 				   !(devctl & MUSB_DEVCTL_BDEVICE), 5000,
492 				   1000000);
493 	if (error) {
494 		dev_err(musb->controller, "%s: could not set host: %02x\n",
495 			__func__, devctl);
496 
497 		return error;
498 	}
499 
500 	devctl = musb_read_devctl(musb);
501 	trace_musb_state(musb, devctl, "Host mode set");
502 
503 init_data:
504 	musb->is_active = 1;
505 	musb->xceiv->otg->state = OTG_STATE_A_IDLE;
506 	MUSB_HST_MODE(musb);
507 
508 	return error;
509 }
510 EXPORT_SYMBOL_GPL(musb_set_host);
511 
512 /**
513  * musb_set_peripheral - set and initialize peripheral mode
514  * @musb: musb controller driver data
515  *
516  * Clears devctl session bit and initializes things for peripheral
517  * mode and sets B_IDLE. SoC glue needs to advance state further
518  * based on phy provided VBUS state.
519  */
520 int musb_set_peripheral(struct musb *musb)
521 {
522 	int error = 0;
523 	u8 devctl;
524 
525 	if (!musb)
526 		return -EINVAL;
527 
528 	devctl = musb_read_devctl(musb);
529 	if (devctl & MUSB_DEVCTL_BDEVICE) {
530 		trace_musb_state(musb, devctl, "Already in peripheral mode");
531 		goto init_data;
532 	}
533 
534 	devctl &= ~MUSB_DEVCTL_SESSION;
535 	musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
536 
537 	error = readx_poll_timeout(musb_read_devctl, musb, devctl,
538 				   devctl & MUSB_DEVCTL_BDEVICE, 5000,
539 				   1000000);
540 	if (error) {
541 		dev_err(musb->controller, "%s: could not set peripheral: %02x\n",
542 			__func__, devctl);
543 
544 		return error;
545 	}
546 
547 	devctl = musb_read_devctl(musb);
548 	trace_musb_state(musb, devctl, "Peripheral mode set");
549 
550 init_data:
551 	musb->is_active = 0;
552 	musb->xceiv->otg->state = OTG_STATE_B_IDLE;
553 	MUSB_DEV_MODE(musb);
554 
555 	return error;
556 }
557 EXPORT_SYMBOL_GPL(musb_set_peripheral);
558 
559 /*-------------------------------------------------------------------------*/
560 
561 /* for high speed test mode; see USB 2.0 spec 7.1.20 */
562 static const u8 musb_test_packet[53] = {
563 	/* implicit SYNC then DATA0 to start */
564 
565 	/* JKJKJKJK x9 */
566 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
567 	/* JJKKJJKK x8 */
568 	0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
569 	/* JJJJKKKK x8 */
570 	0xee, 0xee, 0xee, 0xee, 0xee, 0xee, 0xee, 0xee,
571 	/* JJJJJJJKKKKKKK x8 */
572 	0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
573 	/* JJJJJJJK x8 */
574 	0x7f, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd,
575 	/* JKKKKKKK x10, JK */
576 	0xfc, 0x7e, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd, 0x7e
577 
578 	/* implicit CRC16 then EOP to end */
579 };
580 
581 void musb_load_testpacket(struct musb *musb)
582 {
583 	void __iomem	*regs = musb->endpoints[0].regs;
584 
585 	musb_ep_select(musb->mregs, 0);
586 	musb_write_fifo(musb->control_ep,
587 			sizeof(musb_test_packet), musb_test_packet);
588 	musb_writew(regs, MUSB_CSR0, MUSB_CSR0_TXPKTRDY);
589 }
590 
591 /*-------------------------------------------------------------------------*/
592 
593 /*
594  * Handles OTG hnp timeouts, such as b_ase0_brst
595  */
596 static void musb_otg_timer_func(struct timer_list *t)
597 {
598 	struct musb	*musb = from_timer(musb, t, otg_timer);
599 	unsigned long	flags;
600 
601 	spin_lock_irqsave(&musb->lock, flags);
602 	switch (musb->xceiv->otg->state) {
603 	case OTG_STATE_B_WAIT_ACON:
604 		musb_dbg(musb,
605 			"HNP: b_wait_acon timeout; back to b_peripheral");
606 		musb_g_disconnect(musb);
607 		musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
608 		musb->is_active = 0;
609 		break;
610 	case OTG_STATE_A_SUSPEND:
611 	case OTG_STATE_A_WAIT_BCON:
612 		musb_dbg(musb, "HNP: %s timeout",
613 			usb_otg_state_string(musb->xceiv->otg->state));
614 		musb_platform_set_vbus(musb, 0);
615 		musb->xceiv->otg->state = OTG_STATE_A_WAIT_VFALL;
616 		break;
617 	default:
618 		musb_dbg(musb, "HNP: Unhandled mode %s",
619 			usb_otg_state_string(musb->xceiv->otg->state));
620 	}
621 	spin_unlock_irqrestore(&musb->lock, flags);
622 }
623 
624 /*
625  * Stops the HNP transition. Caller must take care of locking.
626  */
627 void musb_hnp_stop(struct musb *musb)
628 {
629 	struct usb_hcd	*hcd = musb->hcd;
630 	void __iomem	*mbase = musb->mregs;
631 	u8	reg;
632 
633 	musb_dbg(musb, "HNP: stop from %s",
634 			usb_otg_state_string(musb->xceiv->otg->state));
635 
636 	switch (musb->xceiv->otg->state) {
637 	case OTG_STATE_A_PERIPHERAL:
638 		musb_g_disconnect(musb);
639 		musb_dbg(musb, "HNP: back to %s",
640 			usb_otg_state_string(musb->xceiv->otg->state));
641 		break;
642 	case OTG_STATE_B_HOST:
643 		musb_dbg(musb, "HNP: Disabling HR");
644 		if (hcd)
645 			hcd->self.is_b_host = 0;
646 		musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
647 		MUSB_DEV_MODE(musb);
648 		reg = musb_readb(mbase, MUSB_POWER);
649 		reg |= MUSB_POWER_SUSPENDM;
650 		musb_writeb(mbase, MUSB_POWER, reg);
651 		/* REVISIT: Start SESSION_REQUEST here? */
652 		break;
653 	default:
654 		musb_dbg(musb, "HNP: Stopping in unknown state %s",
655 			usb_otg_state_string(musb->xceiv->otg->state));
656 	}
657 
658 	/*
659 	 * When returning to A state after HNP, avoid hub_port_rebounce(),
660 	 * which cause occasional OPT A "Did not receive reset after connect"
661 	 * errors.
662 	 */
663 	musb->port1_status &= ~(USB_PORT_STAT_C_CONNECTION << 16);
664 }
665 
666 static void musb_recover_from_babble(struct musb *musb);
667 
668 static void musb_handle_intr_resume(struct musb *musb, u8 devctl)
669 {
670 	musb_dbg(musb, "RESUME (%s)",
671 			usb_otg_state_string(musb->xceiv->otg->state));
672 
673 	if (devctl & MUSB_DEVCTL_HM) {
674 		switch (musb->xceiv->otg->state) {
675 		case OTG_STATE_A_SUSPEND:
676 			/* remote wakeup? */
677 			musb->port1_status |=
678 					(USB_PORT_STAT_C_SUSPEND << 16)
679 					| MUSB_PORT_STAT_RESUME;
680 			musb->rh_timer = jiffies
681 				+ msecs_to_jiffies(USB_RESUME_TIMEOUT);
682 			musb->xceiv->otg->state = OTG_STATE_A_HOST;
683 			musb->is_active = 1;
684 			musb_host_resume_root_hub(musb);
685 			schedule_delayed_work(&musb->finish_resume_work,
686 				msecs_to_jiffies(USB_RESUME_TIMEOUT));
687 			break;
688 		case OTG_STATE_B_WAIT_ACON:
689 			musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
690 			musb->is_active = 1;
691 			MUSB_DEV_MODE(musb);
692 			break;
693 		default:
694 			WARNING("bogus %s RESUME (%s)\n",
695 				"host",
696 				usb_otg_state_string(musb->xceiv->otg->state));
697 		}
698 	} else {
699 		switch (musb->xceiv->otg->state) {
700 		case OTG_STATE_A_SUSPEND:
701 			/* possibly DISCONNECT is upcoming */
702 			musb->xceiv->otg->state = OTG_STATE_A_HOST;
703 			musb_host_resume_root_hub(musb);
704 			break;
705 		case OTG_STATE_B_WAIT_ACON:
706 		case OTG_STATE_B_PERIPHERAL:
707 			/* disconnect while suspended?  we may
708 			 * not get a disconnect irq...
709 			 */
710 			if ((devctl & MUSB_DEVCTL_VBUS)
711 					!= (3 << MUSB_DEVCTL_VBUS_SHIFT)
712 					) {
713 				musb->int_usb |= MUSB_INTR_DISCONNECT;
714 				musb->int_usb &= ~MUSB_INTR_SUSPEND;
715 				break;
716 			}
717 			musb_g_resume(musb);
718 			break;
719 		case OTG_STATE_B_IDLE:
720 			musb->int_usb &= ~MUSB_INTR_SUSPEND;
721 			break;
722 		default:
723 			WARNING("bogus %s RESUME (%s)\n",
724 				"peripheral",
725 				usb_otg_state_string(musb->xceiv->otg->state));
726 		}
727 	}
728 }
729 
730 /* return IRQ_HANDLED to tell the caller to return immediately */
731 static irqreturn_t musb_handle_intr_sessreq(struct musb *musb, u8 devctl)
732 {
733 	void __iomem *mbase = musb->mregs;
734 
735 	if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS
736 			&& (devctl & MUSB_DEVCTL_BDEVICE)) {
737 		musb_dbg(musb, "SessReq while on B state");
738 		return IRQ_HANDLED;
739 	}
740 
741 	musb_dbg(musb, "SESSION_REQUEST (%s)",
742 		usb_otg_state_string(musb->xceiv->otg->state));
743 
744 	/* IRQ arrives from ID pin sense or (later, if VBUS power
745 	 * is removed) SRP.  responses are time critical:
746 	 *  - turn on VBUS (with silicon-specific mechanism)
747 	 *  - go through A_WAIT_VRISE
748 	 *  - ... to A_WAIT_BCON.
749 	 * a_wait_vrise_tmout triggers VBUS_ERROR transitions
750 	 */
751 	musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
752 	musb->ep0_stage = MUSB_EP0_START;
753 	musb->xceiv->otg->state = OTG_STATE_A_IDLE;
754 	MUSB_HST_MODE(musb);
755 	musb_platform_set_vbus(musb, 1);
756 
757 	return IRQ_NONE;
758 }
759 
760 static void musb_handle_intr_vbuserr(struct musb *musb, u8 devctl)
761 {
762 	int	ignore = 0;
763 
764 	/* During connection as an A-Device, we may see a short
765 	 * current spikes causing voltage drop, because of cable
766 	 * and peripheral capacitance combined with vbus draw.
767 	 * (So: less common with truly self-powered devices, where
768 	 * vbus doesn't act like a power supply.)
769 	 *
770 	 * Such spikes are short; usually less than ~500 usec, max
771 	 * of ~2 msec.  That is, they're not sustained overcurrent
772 	 * errors, though they're reported using VBUSERROR irqs.
773 	 *
774 	 * Workarounds:  (a) hardware: use self powered devices.
775 	 * (b) software:  ignore non-repeated VBUS errors.
776 	 *
777 	 * REVISIT:  do delays from lots of DEBUG_KERNEL checks
778 	 * make trouble here, keeping VBUS < 4.4V ?
779 	 */
780 	switch (musb->xceiv->otg->state) {
781 	case OTG_STATE_A_HOST:
782 		/* recovery is dicey once we've gotten past the
783 		 * initial stages of enumeration, but if VBUS
784 		 * stayed ok at the other end of the link, and
785 		 * another reset is due (at least for high speed,
786 		 * to redo the chirp etc), it might work OK...
787 		 */
788 	case OTG_STATE_A_WAIT_BCON:
789 	case OTG_STATE_A_WAIT_VRISE:
790 		if (musb->vbuserr_retry) {
791 			void __iomem *mbase = musb->mregs;
792 
793 			musb->vbuserr_retry--;
794 			ignore = 1;
795 			devctl |= MUSB_DEVCTL_SESSION;
796 			musb_writeb(mbase, MUSB_DEVCTL, devctl);
797 		} else {
798 			musb->port1_status |=
799 				  USB_PORT_STAT_OVERCURRENT
800 				| (USB_PORT_STAT_C_OVERCURRENT << 16);
801 		}
802 		break;
803 	default:
804 		break;
805 	}
806 
807 	dev_printk(ignore ? KERN_DEBUG : KERN_ERR, musb->controller,
808 			"VBUS_ERROR in %s (%02x, %s), retry #%d, port1 %08x\n",
809 			usb_otg_state_string(musb->xceiv->otg->state),
810 			devctl,
811 			({ char *s;
812 			switch (devctl & MUSB_DEVCTL_VBUS) {
813 			case 0 << MUSB_DEVCTL_VBUS_SHIFT:
814 				s = "<SessEnd"; break;
815 			case 1 << MUSB_DEVCTL_VBUS_SHIFT:
816 				s = "<AValid"; break;
817 			case 2 << MUSB_DEVCTL_VBUS_SHIFT:
818 				s = "<VBusValid"; break;
819 			/* case 3 << MUSB_DEVCTL_VBUS_SHIFT: */
820 			default:
821 				s = "VALID"; break;
822 			} s; }),
823 			VBUSERR_RETRY_COUNT - musb->vbuserr_retry,
824 			musb->port1_status);
825 
826 	/* go through A_WAIT_VFALL then start a new session */
827 	if (!ignore)
828 		musb_platform_set_vbus(musb, 0);
829 }
830 
831 static void musb_handle_intr_suspend(struct musb *musb, u8 devctl)
832 {
833 	musb_dbg(musb, "SUSPEND (%s) devctl %02x",
834 		usb_otg_state_string(musb->xceiv->otg->state), devctl);
835 
836 	switch (musb->xceiv->otg->state) {
837 	case OTG_STATE_A_PERIPHERAL:
838 		/* We also come here if the cable is removed, since
839 		 * this silicon doesn't report ID-no-longer-grounded.
840 		 *
841 		 * We depend on T(a_wait_bcon) to shut us down, and
842 		 * hope users don't do anything dicey during this
843 		 * undesired detour through A_WAIT_BCON.
844 		 */
845 		musb_hnp_stop(musb);
846 		musb_host_resume_root_hub(musb);
847 		musb_root_disconnect(musb);
848 		musb_platform_try_idle(musb, jiffies
849 				+ msecs_to_jiffies(musb->a_wait_bcon
850 					? : OTG_TIME_A_WAIT_BCON));
851 
852 		break;
853 	case OTG_STATE_B_IDLE:
854 		if (!musb->is_active)
855 			break;
856 		fallthrough;
857 	case OTG_STATE_B_PERIPHERAL:
858 		musb_g_suspend(musb);
859 		musb->is_active = musb->g.b_hnp_enable;
860 		if (musb->is_active) {
861 			musb->xceiv->otg->state = OTG_STATE_B_WAIT_ACON;
862 			musb_dbg(musb, "HNP: Setting timer for b_ase0_brst");
863 			mod_timer(&musb->otg_timer, jiffies
864 				+ msecs_to_jiffies(
865 						OTG_TIME_B_ASE0_BRST));
866 		}
867 		break;
868 	case OTG_STATE_A_WAIT_BCON:
869 		if (musb->a_wait_bcon != 0)
870 			musb_platform_try_idle(musb, jiffies
871 				+ msecs_to_jiffies(musb->a_wait_bcon));
872 		break;
873 	case OTG_STATE_A_HOST:
874 		musb->xceiv->otg->state = OTG_STATE_A_SUSPEND;
875 		musb->is_active = musb->hcd->self.b_hnp_enable;
876 		break;
877 	case OTG_STATE_B_HOST:
878 		/* Transition to B_PERIPHERAL, see 6.8.2.6 p 44 */
879 		musb_dbg(musb, "REVISIT: SUSPEND as B_HOST");
880 		break;
881 	default:
882 		/* "should not happen" */
883 		musb->is_active = 0;
884 		break;
885 	}
886 }
887 
888 static void musb_handle_intr_connect(struct musb *musb, u8 devctl, u8 int_usb)
889 {
890 	struct usb_hcd *hcd = musb->hcd;
891 
892 	musb->is_active = 1;
893 	musb->ep0_stage = MUSB_EP0_START;
894 
895 	musb->intrtxe = musb->epmask;
896 	musb_writew(musb->mregs, MUSB_INTRTXE, musb->intrtxe);
897 	musb->intrrxe = musb->epmask & 0xfffe;
898 	musb_writew(musb->mregs, MUSB_INTRRXE, musb->intrrxe);
899 	musb_writeb(musb->mregs, MUSB_INTRUSBE, 0xf7);
900 	musb->port1_status &= ~(USB_PORT_STAT_LOW_SPEED
901 				|USB_PORT_STAT_HIGH_SPEED
902 				|USB_PORT_STAT_ENABLE
903 				);
904 	musb->port1_status |= USB_PORT_STAT_CONNECTION
905 				|(USB_PORT_STAT_C_CONNECTION << 16);
906 
907 	/* high vs full speed is just a guess until after reset */
908 	if (devctl & MUSB_DEVCTL_LSDEV)
909 		musb->port1_status |= USB_PORT_STAT_LOW_SPEED;
910 
911 	/* indicate new connection to OTG machine */
912 	switch (musb->xceiv->otg->state) {
913 	case OTG_STATE_B_PERIPHERAL:
914 		if (int_usb & MUSB_INTR_SUSPEND) {
915 			musb_dbg(musb, "HNP: SUSPEND+CONNECT, now b_host");
916 			int_usb &= ~MUSB_INTR_SUSPEND;
917 			goto b_host;
918 		} else
919 			musb_dbg(musb, "CONNECT as b_peripheral???");
920 		break;
921 	case OTG_STATE_B_WAIT_ACON:
922 		musb_dbg(musb, "HNP: CONNECT, now b_host");
923 b_host:
924 		musb->xceiv->otg->state = OTG_STATE_B_HOST;
925 		if (musb->hcd)
926 			musb->hcd->self.is_b_host = 1;
927 		del_timer(&musb->otg_timer);
928 		break;
929 	default:
930 		if ((devctl & MUSB_DEVCTL_VBUS)
931 				== (3 << MUSB_DEVCTL_VBUS_SHIFT)) {
932 			musb->xceiv->otg->state = OTG_STATE_A_HOST;
933 			if (hcd)
934 				hcd->self.is_b_host = 0;
935 		}
936 		break;
937 	}
938 
939 	musb_host_poke_root_hub(musb);
940 
941 	musb_dbg(musb, "CONNECT (%s) devctl %02x",
942 			usb_otg_state_string(musb->xceiv->otg->state), devctl);
943 }
944 
945 static void musb_handle_intr_disconnect(struct musb *musb, u8 devctl)
946 {
947 	musb_dbg(musb, "DISCONNECT (%s) as %s, devctl %02x",
948 			usb_otg_state_string(musb->xceiv->otg->state),
949 			MUSB_MODE(musb), devctl);
950 
951 	switch (musb->xceiv->otg->state) {
952 	case OTG_STATE_A_HOST:
953 	case OTG_STATE_A_SUSPEND:
954 		musb_host_resume_root_hub(musb);
955 		musb_root_disconnect(musb);
956 		if (musb->a_wait_bcon != 0)
957 			musb_platform_try_idle(musb, jiffies
958 				+ msecs_to_jiffies(musb->a_wait_bcon));
959 		break;
960 	case OTG_STATE_B_HOST:
961 		/* REVISIT this behaves for "real disconnect"
962 		 * cases; make sure the other transitions from
963 		 * from B_HOST act right too.  The B_HOST code
964 		 * in hnp_stop() is currently not used...
965 		 */
966 		musb_root_disconnect(musb);
967 		if (musb->hcd)
968 			musb->hcd->self.is_b_host = 0;
969 		musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
970 		MUSB_DEV_MODE(musb);
971 		musb_g_disconnect(musb);
972 		break;
973 	case OTG_STATE_A_PERIPHERAL:
974 		musb_hnp_stop(musb);
975 		musb_root_disconnect(musb);
976 		fallthrough;
977 	case OTG_STATE_B_WAIT_ACON:
978 	case OTG_STATE_B_PERIPHERAL:
979 	case OTG_STATE_B_IDLE:
980 		musb_g_disconnect(musb);
981 		break;
982 	default:
983 		WARNING("unhandled DISCONNECT transition (%s)\n",
984 			usb_otg_state_string(musb->xceiv->otg->state));
985 		break;
986 	}
987 }
988 
989 /*
990  * mentor saves a bit: bus reset and babble share the same irq.
991  * only host sees babble; only peripheral sees bus reset.
992  */
993 static void musb_handle_intr_reset(struct musb *musb)
994 {
995 	if (is_host_active(musb)) {
996 		/*
997 		 * When BABBLE happens what we can depends on which
998 		 * platform MUSB is running, because some platforms
999 		 * implemented proprietary means for 'recovering' from
1000 		 * Babble conditions. One such platform is AM335x. In
1001 		 * most cases, however, the only thing we can do is
1002 		 * drop the session.
1003 		 */
1004 		dev_err(musb->controller, "Babble\n");
1005 		musb_recover_from_babble(musb);
1006 	} else {
1007 		musb_dbg(musb, "BUS RESET as %s",
1008 			usb_otg_state_string(musb->xceiv->otg->state));
1009 		switch (musb->xceiv->otg->state) {
1010 		case OTG_STATE_A_SUSPEND:
1011 			musb_g_reset(musb);
1012 			fallthrough;
1013 		case OTG_STATE_A_WAIT_BCON:	/* OPT TD.4.7-900ms */
1014 			/* never use invalid T(a_wait_bcon) */
1015 			musb_dbg(musb, "HNP: in %s, %d msec timeout",
1016 				usb_otg_state_string(musb->xceiv->otg->state),
1017 				TA_WAIT_BCON(musb));
1018 			mod_timer(&musb->otg_timer, jiffies
1019 				+ msecs_to_jiffies(TA_WAIT_BCON(musb)));
1020 			break;
1021 		case OTG_STATE_A_PERIPHERAL:
1022 			del_timer(&musb->otg_timer);
1023 			musb_g_reset(musb);
1024 			break;
1025 		case OTG_STATE_B_WAIT_ACON:
1026 			musb_dbg(musb, "HNP: RESET (%s), to b_peripheral",
1027 				usb_otg_state_string(musb->xceiv->otg->state));
1028 			musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
1029 			musb_g_reset(musb);
1030 			break;
1031 		case OTG_STATE_B_IDLE:
1032 			musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
1033 			fallthrough;
1034 		case OTG_STATE_B_PERIPHERAL:
1035 			musb_g_reset(musb);
1036 			break;
1037 		default:
1038 			musb_dbg(musb, "Unhandled BUS RESET as %s",
1039 				usb_otg_state_string(musb->xceiv->otg->state));
1040 		}
1041 	}
1042 }
1043 
1044 /*
1045  * Interrupt Service Routine to record USB "global" interrupts.
1046  * Since these do not happen often and signify things of
1047  * paramount importance, it seems OK to check them individually;
1048  * the order of the tests is specified in the manual
1049  *
1050  * @param musb instance pointer
1051  * @param int_usb register contents
1052  * @param devctl
1053  */
1054 
1055 static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb,
1056 				u8 devctl)
1057 {
1058 	irqreturn_t handled = IRQ_NONE;
1059 
1060 	musb_dbg(musb, "<== DevCtl=%02x, int_usb=0x%x", devctl, int_usb);
1061 
1062 	/* in host mode, the peripheral may issue remote wakeup.
1063 	 * in peripheral mode, the host may resume the link.
1064 	 * spurious RESUME irqs happen too, paired with SUSPEND.
1065 	 */
1066 	if (int_usb & MUSB_INTR_RESUME) {
1067 		musb_handle_intr_resume(musb, devctl);
1068 		handled = IRQ_HANDLED;
1069 	}
1070 
1071 	/* see manual for the order of the tests */
1072 	if (int_usb & MUSB_INTR_SESSREQ) {
1073 		if (musb_handle_intr_sessreq(musb, devctl))
1074 			return IRQ_HANDLED;
1075 		handled = IRQ_HANDLED;
1076 	}
1077 
1078 	if (int_usb & MUSB_INTR_VBUSERROR) {
1079 		musb_handle_intr_vbuserr(musb, devctl);
1080 		handled = IRQ_HANDLED;
1081 	}
1082 
1083 	if (int_usb & MUSB_INTR_SUSPEND) {
1084 		musb_handle_intr_suspend(musb, devctl);
1085 		handled = IRQ_HANDLED;
1086 	}
1087 
1088 	if (int_usb & MUSB_INTR_CONNECT) {
1089 		musb_handle_intr_connect(musb, devctl, int_usb);
1090 		handled = IRQ_HANDLED;
1091 	}
1092 
1093 	if (int_usb & MUSB_INTR_DISCONNECT) {
1094 		musb_handle_intr_disconnect(musb, devctl);
1095 		handled = IRQ_HANDLED;
1096 	}
1097 
1098 	if (int_usb & MUSB_INTR_RESET) {
1099 		musb_handle_intr_reset(musb);
1100 		handled = IRQ_HANDLED;
1101 	}
1102 
1103 #if 0
1104 /* REVISIT ... this would be for multiplexing periodic endpoints, or
1105  * supporting transfer phasing to prevent exceeding ISO bandwidth
1106  * limits of a given frame or microframe.
1107  *
1108  * It's not needed for peripheral side, which dedicates endpoints;
1109  * though it _might_ use SOF irqs for other purposes.
1110  *
1111  * And it's not currently needed for host side, which also dedicates
1112  * endpoints, relies on TX/RX interval registers, and isn't claimed
1113  * to support ISO transfers yet.
1114  */
1115 	if (int_usb & MUSB_INTR_SOF) {
1116 		void __iomem *mbase = musb->mregs;
1117 		struct musb_hw_ep	*ep;
1118 		u8 epnum;
1119 		u16 frame;
1120 
1121 		dev_dbg(musb->controller, "START_OF_FRAME\n");
1122 		handled = IRQ_HANDLED;
1123 
1124 		/* start any periodic Tx transfers waiting for current frame */
1125 		frame = musb_readw(mbase, MUSB_FRAME);
1126 		ep = musb->endpoints;
1127 		for (epnum = 1; (epnum < musb->nr_endpoints)
1128 					&& (musb->epmask >= (1 << epnum));
1129 				epnum++, ep++) {
1130 			/*
1131 			 * FIXME handle framecounter wraps (12 bits)
1132 			 * eliminate duplicated StartUrb logic
1133 			 */
1134 			if (ep->dwWaitFrame >= frame) {
1135 				ep->dwWaitFrame = 0;
1136 				pr_debug("SOF --> periodic TX%s on %d\n",
1137 					ep->tx_channel ? " DMA" : "",
1138 					epnum);
1139 				if (!ep->tx_channel)
1140 					musb_h_tx_start(musb, epnum);
1141 				else
1142 					cppi_hostdma_start(musb, epnum);
1143 			}
1144 		}		/* end of for loop */
1145 	}
1146 #endif
1147 
1148 	schedule_delayed_work(&musb->irq_work, 0);
1149 
1150 	return handled;
1151 }
1152 
1153 /*-------------------------------------------------------------------------*/
1154 
1155 static void musb_disable_interrupts(struct musb *musb)
1156 {
1157 	void __iomem	*mbase = musb->mregs;
1158 
1159 	/* disable interrupts */
1160 	musb_writeb(mbase, MUSB_INTRUSBE, 0);
1161 	musb->intrtxe = 0;
1162 	musb_writew(mbase, MUSB_INTRTXE, 0);
1163 	musb->intrrxe = 0;
1164 	musb_writew(mbase, MUSB_INTRRXE, 0);
1165 
1166 	/*  flush pending interrupts */
1167 	musb_clearb(mbase, MUSB_INTRUSB);
1168 	musb_clearw(mbase, MUSB_INTRTX);
1169 	musb_clearw(mbase, MUSB_INTRRX);
1170 }
1171 
1172 static void musb_enable_interrupts(struct musb *musb)
1173 {
1174 	void __iomem    *regs = musb->mregs;
1175 
1176 	/*  Set INT enable registers, enable interrupts */
1177 	musb->intrtxe = musb->epmask;
1178 	musb_writew(regs, MUSB_INTRTXE, musb->intrtxe);
1179 	musb->intrrxe = musb->epmask & 0xfffe;
1180 	musb_writew(regs, MUSB_INTRRXE, musb->intrrxe);
1181 	musb_writeb(regs, MUSB_INTRUSBE, 0xf7);
1182 
1183 }
1184 
1185 /*
1186  * Program the HDRC to start (enable interrupts, dma, etc.).
1187  */
1188 void musb_start(struct musb *musb)
1189 {
1190 	void __iomem    *regs = musb->mregs;
1191 	u8              devctl = musb_readb(regs, MUSB_DEVCTL);
1192 	u8		power;
1193 
1194 	musb_dbg(musb, "<== devctl %02x", devctl);
1195 
1196 	musb_enable_interrupts(musb);
1197 	musb_writeb(regs, MUSB_TESTMODE, 0);
1198 
1199 	power = MUSB_POWER_ISOUPDATE;
1200 	/*
1201 	 * treating UNKNOWN as unspecified maximum speed, in which case
1202 	 * we will default to high-speed.
1203 	 */
1204 	if (musb->config->maximum_speed == USB_SPEED_HIGH ||
1205 			musb->config->maximum_speed == USB_SPEED_UNKNOWN)
1206 		power |= MUSB_POWER_HSENAB;
1207 	musb_writeb(regs, MUSB_POWER, power);
1208 
1209 	musb->is_active = 0;
1210 	devctl = musb_readb(regs, MUSB_DEVCTL);
1211 	devctl &= ~MUSB_DEVCTL_SESSION;
1212 
1213 	/* session started after:
1214 	 * (a) ID-grounded irq, host mode;
1215 	 * (b) vbus present/connect IRQ, peripheral mode;
1216 	 * (c) peripheral initiates, using SRP
1217 	 */
1218 	if (musb->port_mode != MUSB_HOST &&
1219 			musb->xceiv->otg->state != OTG_STATE_A_WAIT_BCON &&
1220 			(devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS) {
1221 		musb->is_active = 1;
1222 	} else {
1223 		devctl |= MUSB_DEVCTL_SESSION;
1224 	}
1225 
1226 	musb_platform_enable(musb);
1227 	musb_writeb(regs, MUSB_DEVCTL, devctl);
1228 }
1229 
1230 /*
1231  * Make the HDRC stop (disable interrupts, etc.);
1232  * reversible by musb_start
1233  * called on gadget driver unregister
1234  * with controller locked, irqs blocked
1235  * acts as a NOP unless some role activated the hardware
1236  */
1237 void musb_stop(struct musb *musb)
1238 {
1239 	/* stop IRQs, timers, ... */
1240 	musb_platform_disable(musb);
1241 	musb_disable_interrupts(musb);
1242 	musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
1243 
1244 	/* FIXME
1245 	 *  - mark host and/or peripheral drivers unusable/inactive
1246 	 *  - disable DMA (and enable it in HdrcStart)
1247 	 *  - make sure we can musb_start() after musb_stop(); with
1248 	 *    OTG mode, gadget driver module rmmod/modprobe cycles that
1249 	 *  - ...
1250 	 */
1251 	musb_platform_try_idle(musb, 0);
1252 }
1253 
1254 /*-------------------------------------------------------------------------*/
1255 
1256 /*
1257  * The silicon either has hard-wired endpoint configurations, or else
1258  * "dynamic fifo" sizing.  The driver has support for both, though at this
1259  * writing only the dynamic sizing is very well tested.   Since we switched
1260  * away from compile-time hardware parameters, we can no longer rely on
1261  * dead code elimination to leave only the relevant one in the object file.
1262  *
1263  * We don't currently use dynamic fifo setup capability to do anything
1264  * more than selecting one of a bunch of predefined configurations.
1265  */
1266 static ushort fifo_mode;
1267 
1268 /* "modprobe ... fifo_mode=1" etc */
1269 module_param(fifo_mode, ushort, 0);
1270 MODULE_PARM_DESC(fifo_mode, "initial endpoint configuration");
1271 
1272 /*
1273  * tables defining fifo_mode values.  define more if you like.
1274  * for host side, make sure both halves of ep1 are set up.
1275  */
1276 
1277 /* mode 0 - fits in 2KB */
1278 static struct musb_fifo_cfg mode_0_cfg[] = {
1279 { .hw_ep_num = 1, .style = FIFO_TX,   .maxpacket = 512, },
1280 { .hw_ep_num = 1, .style = FIFO_RX,   .maxpacket = 512, },
1281 { .hw_ep_num = 2, .style = FIFO_RXTX, .maxpacket = 512, },
1282 { .hw_ep_num = 3, .style = FIFO_RXTX, .maxpacket = 256, },
1283 { .hw_ep_num = 4, .style = FIFO_RXTX, .maxpacket = 256, },
1284 };
1285 
1286 /* mode 1 - fits in 4KB */
1287 static struct musb_fifo_cfg mode_1_cfg[] = {
1288 { .hw_ep_num = 1, .style = FIFO_TX,   .maxpacket = 512, .mode = BUF_DOUBLE, },
1289 { .hw_ep_num = 1, .style = FIFO_RX,   .maxpacket = 512, .mode = BUF_DOUBLE, },
1290 { .hw_ep_num = 2, .style = FIFO_RXTX, .maxpacket = 512, .mode = BUF_DOUBLE, },
1291 { .hw_ep_num = 3, .style = FIFO_RXTX, .maxpacket = 256, },
1292 { .hw_ep_num = 4, .style = FIFO_RXTX, .maxpacket = 256, },
1293 };
1294 
1295 /* mode 2 - fits in 4KB */
1296 static struct musb_fifo_cfg mode_2_cfg[] = {
1297 { .hw_ep_num = 1, .style = FIFO_TX,   .maxpacket = 512, },
1298 { .hw_ep_num = 1, .style = FIFO_RX,   .maxpacket = 512, },
1299 { .hw_ep_num = 2, .style = FIFO_TX,   .maxpacket = 512, },
1300 { .hw_ep_num = 2, .style = FIFO_RX,   .maxpacket = 512, },
1301 { .hw_ep_num = 3, .style = FIFO_RXTX, .maxpacket = 960, },
1302 { .hw_ep_num = 4, .style = FIFO_RXTX, .maxpacket = 1024, },
1303 };
1304 
1305 /* mode 3 - fits in 4KB */
1306 static struct musb_fifo_cfg mode_3_cfg[] = {
1307 { .hw_ep_num = 1, .style = FIFO_TX,   .maxpacket = 512, .mode = BUF_DOUBLE, },
1308 { .hw_ep_num = 1, .style = FIFO_RX,   .maxpacket = 512, .mode = BUF_DOUBLE, },
1309 { .hw_ep_num = 2, .style = FIFO_TX,   .maxpacket = 512, },
1310 { .hw_ep_num = 2, .style = FIFO_RX,   .maxpacket = 512, },
1311 { .hw_ep_num = 3, .style = FIFO_RXTX, .maxpacket = 256, },
1312 { .hw_ep_num = 4, .style = FIFO_RXTX, .maxpacket = 256, },
1313 };
1314 
1315 /* mode 4 - fits in 16KB */
1316 static struct musb_fifo_cfg mode_4_cfg[] = {
1317 { .hw_ep_num =  1, .style = FIFO_TX,   .maxpacket = 512, },
1318 { .hw_ep_num =  1, .style = FIFO_RX,   .maxpacket = 512, },
1319 { .hw_ep_num =  2, .style = FIFO_TX,   .maxpacket = 512, },
1320 { .hw_ep_num =  2, .style = FIFO_RX,   .maxpacket = 512, },
1321 { .hw_ep_num =  3, .style = FIFO_TX,   .maxpacket = 512, },
1322 { .hw_ep_num =  3, .style = FIFO_RX,   .maxpacket = 512, },
1323 { .hw_ep_num =  4, .style = FIFO_TX,   .maxpacket = 512, },
1324 { .hw_ep_num =  4, .style = FIFO_RX,   .maxpacket = 512, },
1325 { .hw_ep_num =  5, .style = FIFO_TX,   .maxpacket = 512, },
1326 { .hw_ep_num =  5, .style = FIFO_RX,   .maxpacket = 512, },
1327 { .hw_ep_num =  6, .style = FIFO_TX,   .maxpacket = 512, },
1328 { .hw_ep_num =  6, .style = FIFO_RX,   .maxpacket = 512, },
1329 { .hw_ep_num =  7, .style = FIFO_TX,   .maxpacket = 512, },
1330 { .hw_ep_num =  7, .style = FIFO_RX,   .maxpacket = 512, },
1331 { .hw_ep_num =  8, .style = FIFO_TX,   .maxpacket = 512, },
1332 { .hw_ep_num =  8, .style = FIFO_RX,   .maxpacket = 512, },
1333 { .hw_ep_num =  9, .style = FIFO_TX,   .maxpacket = 512, },
1334 { .hw_ep_num =  9, .style = FIFO_RX,   .maxpacket = 512, },
1335 { .hw_ep_num = 10, .style = FIFO_TX,   .maxpacket = 256, },
1336 { .hw_ep_num = 10, .style = FIFO_RX,   .maxpacket = 64, },
1337 { .hw_ep_num = 11, .style = FIFO_TX,   .maxpacket = 256, },
1338 { .hw_ep_num = 11, .style = FIFO_RX,   .maxpacket = 64, },
1339 { .hw_ep_num = 12, .style = FIFO_TX,   .maxpacket = 256, },
1340 { .hw_ep_num = 12, .style = FIFO_RX,   .maxpacket = 64, },
1341 { .hw_ep_num = 13, .style = FIFO_RXTX, .maxpacket = 4096, },
1342 { .hw_ep_num = 14, .style = FIFO_RXTX, .maxpacket = 1024, },
1343 { .hw_ep_num = 15, .style = FIFO_RXTX, .maxpacket = 1024, },
1344 };
1345 
1346 /* mode 5 - fits in 8KB */
1347 static struct musb_fifo_cfg mode_5_cfg[] = {
1348 { .hw_ep_num =  1, .style = FIFO_TX,   .maxpacket = 512, },
1349 { .hw_ep_num =  1, .style = FIFO_RX,   .maxpacket = 512, },
1350 { .hw_ep_num =  2, .style = FIFO_TX,   .maxpacket = 512, },
1351 { .hw_ep_num =  2, .style = FIFO_RX,   .maxpacket = 512, },
1352 { .hw_ep_num =  3, .style = FIFO_TX,   .maxpacket = 512, },
1353 { .hw_ep_num =  3, .style = FIFO_RX,   .maxpacket = 512, },
1354 { .hw_ep_num =  4, .style = FIFO_TX,   .maxpacket = 512, },
1355 { .hw_ep_num =  4, .style = FIFO_RX,   .maxpacket = 512, },
1356 { .hw_ep_num =  5, .style = FIFO_TX,   .maxpacket = 512, },
1357 { .hw_ep_num =  5, .style = FIFO_RX,   .maxpacket = 512, },
1358 { .hw_ep_num =  6, .style = FIFO_TX,   .maxpacket = 32, },
1359 { .hw_ep_num =  6, .style = FIFO_RX,   .maxpacket = 32, },
1360 { .hw_ep_num =  7, .style = FIFO_TX,   .maxpacket = 32, },
1361 { .hw_ep_num =  7, .style = FIFO_RX,   .maxpacket = 32, },
1362 { .hw_ep_num =  8, .style = FIFO_TX,   .maxpacket = 32, },
1363 { .hw_ep_num =  8, .style = FIFO_RX,   .maxpacket = 32, },
1364 { .hw_ep_num =  9, .style = FIFO_TX,   .maxpacket = 32, },
1365 { .hw_ep_num =  9, .style = FIFO_RX,   .maxpacket = 32, },
1366 { .hw_ep_num = 10, .style = FIFO_TX,   .maxpacket = 32, },
1367 { .hw_ep_num = 10, .style = FIFO_RX,   .maxpacket = 32, },
1368 { .hw_ep_num = 11, .style = FIFO_TX,   .maxpacket = 32, },
1369 { .hw_ep_num = 11, .style = FIFO_RX,   .maxpacket = 32, },
1370 { .hw_ep_num = 12, .style = FIFO_TX,   .maxpacket = 32, },
1371 { .hw_ep_num = 12, .style = FIFO_RX,   .maxpacket = 32, },
1372 { .hw_ep_num = 13, .style = FIFO_RXTX, .maxpacket = 512, },
1373 { .hw_ep_num = 14, .style = FIFO_RXTX, .maxpacket = 1024, },
1374 { .hw_ep_num = 15, .style = FIFO_RXTX, .maxpacket = 1024, },
1375 };
1376 
1377 /*
1378  * configure a fifo; for non-shared endpoints, this may be called
1379  * once for a tx fifo and once for an rx fifo.
1380  *
1381  * returns negative errno or offset for next fifo.
1382  */
1383 static int
1384 fifo_setup(struct musb *musb, struct musb_hw_ep  *hw_ep,
1385 		const struct musb_fifo_cfg *cfg, u16 offset)
1386 {
1387 	void __iomem	*mbase = musb->mregs;
1388 	int	size = 0;
1389 	u16	maxpacket = cfg->maxpacket;
1390 	u16	c_off = offset >> 3;
1391 	u8	c_size;
1392 
1393 	/* expect hw_ep has already been zero-initialized */
1394 
1395 	size = ffs(max(maxpacket, (u16) 8)) - 1;
1396 	maxpacket = 1 << size;
1397 
1398 	c_size = size - 3;
1399 	if (cfg->mode == BUF_DOUBLE) {
1400 		if ((offset + (maxpacket << 1)) >
1401 				(1 << (musb->config->ram_bits + 2)))
1402 			return -EMSGSIZE;
1403 		c_size |= MUSB_FIFOSZ_DPB;
1404 	} else {
1405 		if ((offset + maxpacket) > (1 << (musb->config->ram_bits + 2)))
1406 			return -EMSGSIZE;
1407 	}
1408 
1409 	/* configure the FIFO */
1410 	musb_writeb(mbase, MUSB_INDEX, hw_ep->epnum);
1411 
1412 	/* EP0 reserved endpoint for control, bidirectional;
1413 	 * EP1 reserved for bulk, two unidirectional halves.
1414 	 */
1415 	if (hw_ep->epnum == 1)
1416 		musb->bulk_ep = hw_ep;
1417 	/* REVISIT error check:  be sure ep0 can both rx and tx ... */
1418 	switch (cfg->style) {
1419 	case FIFO_TX:
1420 		musb_writeb(mbase, MUSB_TXFIFOSZ, c_size);
1421 		musb_writew(mbase, MUSB_TXFIFOADD, c_off);
1422 		hw_ep->tx_double_buffered = !!(c_size & MUSB_FIFOSZ_DPB);
1423 		hw_ep->max_packet_sz_tx = maxpacket;
1424 		break;
1425 	case FIFO_RX:
1426 		musb_writeb(mbase, MUSB_RXFIFOSZ, c_size);
1427 		musb_writew(mbase, MUSB_RXFIFOADD, c_off);
1428 		hw_ep->rx_double_buffered = !!(c_size & MUSB_FIFOSZ_DPB);
1429 		hw_ep->max_packet_sz_rx = maxpacket;
1430 		break;
1431 	case FIFO_RXTX:
1432 		musb_writeb(mbase, MUSB_TXFIFOSZ, c_size);
1433 		musb_writew(mbase, MUSB_TXFIFOADD, c_off);
1434 		hw_ep->rx_double_buffered = !!(c_size & MUSB_FIFOSZ_DPB);
1435 		hw_ep->max_packet_sz_rx = maxpacket;
1436 
1437 		musb_writeb(mbase, MUSB_RXFIFOSZ, c_size);
1438 		musb_writew(mbase, MUSB_RXFIFOADD, c_off);
1439 		hw_ep->tx_double_buffered = hw_ep->rx_double_buffered;
1440 		hw_ep->max_packet_sz_tx = maxpacket;
1441 
1442 		hw_ep->is_shared_fifo = true;
1443 		break;
1444 	}
1445 
1446 	/* NOTE rx and tx endpoint irqs aren't managed separately,
1447 	 * which happens to be ok
1448 	 */
1449 	musb->epmask |= (1 << hw_ep->epnum);
1450 
1451 	return offset + (maxpacket << ((c_size & MUSB_FIFOSZ_DPB) ? 1 : 0));
1452 }
1453 
1454 static struct musb_fifo_cfg ep0_cfg = {
1455 	.style = FIFO_RXTX, .maxpacket = 64,
1456 };
1457 
1458 static int ep_config_from_table(struct musb *musb)
1459 {
1460 	const struct musb_fifo_cfg	*cfg;
1461 	unsigned		i, n;
1462 	int			offset;
1463 	struct musb_hw_ep	*hw_ep = musb->endpoints;
1464 
1465 	if (musb->config->fifo_cfg) {
1466 		cfg = musb->config->fifo_cfg;
1467 		n = musb->config->fifo_cfg_size;
1468 		goto done;
1469 	}
1470 
1471 	switch (fifo_mode) {
1472 	default:
1473 		fifo_mode = 0;
1474 		fallthrough;
1475 	case 0:
1476 		cfg = mode_0_cfg;
1477 		n = ARRAY_SIZE(mode_0_cfg);
1478 		break;
1479 	case 1:
1480 		cfg = mode_1_cfg;
1481 		n = ARRAY_SIZE(mode_1_cfg);
1482 		break;
1483 	case 2:
1484 		cfg = mode_2_cfg;
1485 		n = ARRAY_SIZE(mode_2_cfg);
1486 		break;
1487 	case 3:
1488 		cfg = mode_3_cfg;
1489 		n = ARRAY_SIZE(mode_3_cfg);
1490 		break;
1491 	case 4:
1492 		cfg = mode_4_cfg;
1493 		n = ARRAY_SIZE(mode_4_cfg);
1494 		break;
1495 	case 5:
1496 		cfg = mode_5_cfg;
1497 		n = ARRAY_SIZE(mode_5_cfg);
1498 		break;
1499 	}
1500 
1501 	pr_debug("%s: setup fifo_mode %d\n", musb_driver_name, fifo_mode);
1502 
1503 
1504 done:
1505 	offset = fifo_setup(musb, hw_ep, &ep0_cfg, 0);
1506 	/* assert(offset > 0) */
1507 
1508 	/* NOTE:  for RTL versions >= 1.400 EPINFO and RAMINFO would
1509 	 * be better than static musb->config->num_eps and DYN_FIFO_SIZE...
1510 	 */
1511 
1512 	for (i = 0; i < n; i++) {
1513 		u8	epn = cfg->hw_ep_num;
1514 
1515 		if (epn >= musb->config->num_eps) {
1516 			pr_debug("%s: invalid ep %d\n",
1517 					musb_driver_name, epn);
1518 			return -EINVAL;
1519 		}
1520 		offset = fifo_setup(musb, hw_ep + epn, cfg++, offset);
1521 		if (offset < 0) {
1522 			pr_debug("%s: mem overrun, ep %d\n",
1523 					musb_driver_name, epn);
1524 			return offset;
1525 		}
1526 		epn++;
1527 		musb->nr_endpoints = max(epn, musb->nr_endpoints);
1528 	}
1529 
1530 	pr_debug("%s: %d/%d max ep, %d/%d memory\n",
1531 			musb_driver_name,
1532 			n + 1, musb->config->num_eps * 2 - 1,
1533 			offset, (1 << (musb->config->ram_bits + 2)));
1534 
1535 	if (!musb->bulk_ep) {
1536 		pr_debug("%s: missing bulk\n", musb_driver_name);
1537 		return -EINVAL;
1538 	}
1539 
1540 	return 0;
1541 }
1542 
1543 
1544 /*
1545  * ep_config_from_hw - when MUSB_C_DYNFIFO_DEF is false
1546  * @param musb the controller
1547  */
1548 static int ep_config_from_hw(struct musb *musb)
1549 {
1550 	u8 epnum = 0;
1551 	struct musb_hw_ep *hw_ep;
1552 	void __iomem *mbase = musb->mregs;
1553 	int ret = 0;
1554 
1555 	musb_dbg(musb, "<== static silicon ep config");
1556 
1557 	/* FIXME pick up ep0 maxpacket size */
1558 
1559 	for (epnum = 1; epnum < musb->config->num_eps; epnum++) {
1560 		musb_ep_select(mbase, epnum);
1561 		hw_ep = musb->endpoints + epnum;
1562 
1563 		ret = musb_read_fifosize(musb, hw_ep, epnum);
1564 		if (ret < 0)
1565 			break;
1566 
1567 		/* FIXME set up hw_ep->{rx,tx}_double_buffered */
1568 
1569 		/* pick an RX/TX endpoint for bulk */
1570 		if (hw_ep->max_packet_sz_tx < 512
1571 				|| hw_ep->max_packet_sz_rx < 512)
1572 			continue;
1573 
1574 		/* REVISIT:  this algorithm is lazy, we should at least
1575 		 * try to pick a double buffered endpoint.
1576 		 */
1577 		if (musb->bulk_ep)
1578 			continue;
1579 		musb->bulk_ep = hw_ep;
1580 	}
1581 
1582 	if (!musb->bulk_ep) {
1583 		pr_debug("%s: missing bulk\n", musb_driver_name);
1584 		return -EINVAL;
1585 	}
1586 
1587 	return 0;
1588 }
1589 
1590 enum { MUSB_CONTROLLER_MHDRC, MUSB_CONTROLLER_HDRC, };
1591 
1592 /* Initialize MUSB (M)HDRC part of the USB hardware subsystem;
1593  * configure endpoints, or take their config from silicon
1594  */
1595 static int musb_core_init(u16 musb_type, struct musb *musb)
1596 {
1597 	u8 reg;
1598 	char *type;
1599 	char aInfo[90];
1600 	void __iomem	*mbase = musb->mregs;
1601 	int		status = 0;
1602 	int		i;
1603 
1604 	/* log core options (read using indexed model) */
1605 	reg = musb_read_configdata(mbase);
1606 
1607 	strcpy(aInfo, (reg & MUSB_CONFIGDATA_UTMIDW) ? "UTMI-16" : "UTMI-8");
1608 	if (reg & MUSB_CONFIGDATA_DYNFIFO) {
1609 		strcat(aInfo, ", dyn FIFOs");
1610 		musb->dyn_fifo = true;
1611 	}
1612 	if (reg & MUSB_CONFIGDATA_MPRXE) {
1613 		strcat(aInfo, ", bulk combine");
1614 		musb->bulk_combine = true;
1615 	}
1616 	if (reg & MUSB_CONFIGDATA_MPTXE) {
1617 		strcat(aInfo, ", bulk split");
1618 		musb->bulk_split = true;
1619 	}
1620 	if (reg & MUSB_CONFIGDATA_HBRXE) {
1621 		strcat(aInfo, ", HB-ISO Rx");
1622 		musb->hb_iso_rx = true;
1623 	}
1624 	if (reg & MUSB_CONFIGDATA_HBTXE) {
1625 		strcat(aInfo, ", HB-ISO Tx");
1626 		musb->hb_iso_tx = true;
1627 	}
1628 	if (reg & MUSB_CONFIGDATA_SOFTCONE)
1629 		strcat(aInfo, ", SoftConn");
1630 
1631 	pr_debug("%s: ConfigData=0x%02x (%s)\n", musb_driver_name, reg, aInfo);
1632 
1633 	if (MUSB_CONTROLLER_MHDRC == musb_type) {
1634 		musb->is_multipoint = 1;
1635 		type = "M";
1636 	} else {
1637 		musb->is_multipoint = 0;
1638 		type = "";
1639 		if (IS_ENABLED(CONFIG_USB) &&
1640 		    !IS_ENABLED(CONFIG_USB_OTG_DISABLE_EXTERNAL_HUB)) {
1641 			pr_err("%s: kernel must disable external hubs, please fix the configuration\n",
1642 			       musb_driver_name);
1643 		}
1644 	}
1645 
1646 	/* log release info */
1647 	musb->hwvers = musb_readw(mbase, MUSB_HWVERS);
1648 	pr_debug("%s: %sHDRC RTL version %d.%d%s\n",
1649 		 musb_driver_name, type, MUSB_HWVERS_MAJOR(musb->hwvers),
1650 		 MUSB_HWVERS_MINOR(musb->hwvers),
1651 		 (musb->hwvers & MUSB_HWVERS_RC) ? "RC" : "");
1652 
1653 	/* configure ep0 */
1654 	musb_configure_ep0(musb);
1655 
1656 	/* discover endpoint configuration */
1657 	musb->nr_endpoints = 1;
1658 	musb->epmask = 1;
1659 
1660 	if (musb->dyn_fifo)
1661 		status = ep_config_from_table(musb);
1662 	else
1663 		status = ep_config_from_hw(musb);
1664 
1665 	if (status < 0)
1666 		return status;
1667 
1668 	/* finish init, and print endpoint config */
1669 	for (i = 0; i < musb->nr_endpoints; i++) {
1670 		struct musb_hw_ep	*hw_ep = musb->endpoints + i;
1671 
1672 		hw_ep->fifo = musb->io.fifo_offset(i) + mbase;
1673 #if IS_ENABLED(CONFIG_USB_MUSB_TUSB6010)
1674 		if (musb->ops->quirks & MUSB_IN_TUSB) {
1675 			hw_ep->fifo_async = musb->async + 0x400 +
1676 				musb->io.fifo_offset(i);
1677 			hw_ep->fifo_sync = musb->sync + 0x400 +
1678 				musb->io.fifo_offset(i);
1679 			hw_ep->fifo_sync_va =
1680 				musb->sync_va + 0x400 + musb->io.fifo_offset(i);
1681 
1682 			if (i == 0)
1683 				hw_ep->conf = mbase - 0x400 + TUSB_EP0_CONF;
1684 			else
1685 				hw_ep->conf = mbase + 0x400 +
1686 					(((i - 1) & 0xf) << 2);
1687 		}
1688 #endif
1689 
1690 		hw_ep->regs = musb->io.ep_offset(i, 0) + mbase;
1691 		hw_ep->rx_reinit = 1;
1692 		hw_ep->tx_reinit = 1;
1693 
1694 		if (hw_ep->max_packet_sz_tx) {
1695 			musb_dbg(musb, "%s: hw_ep %d%s, %smax %d",
1696 				musb_driver_name, i,
1697 				hw_ep->is_shared_fifo ? "shared" : "tx",
1698 				hw_ep->tx_double_buffered
1699 					? "doublebuffer, " : "",
1700 				hw_ep->max_packet_sz_tx);
1701 		}
1702 		if (hw_ep->max_packet_sz_rx && !hw_ep->is_shared_fifo) {
1703 			musb_dbg(musb, "%s: hw_ep %d%s, %smax %d",
1704 				musb_driver_name, i,
1705 				"rx",
1706 				hw_ep->rx_double_buffered
1707 					? "doublebuffer, " : "",
1708 				hw_ep->max_packet_sz_rx);
1709 		}
1710 		if (!(hw_ep->max_packet_sz_tx || hw_ep->max_packet_sz_rx))
1711 			musb_dbg(musb, "hw_ep %d not configured", i);
1712 	}
1713 
1714 	return 0;
1715 }
1716 
1717 /*-------------------------------------------------------------------------*/
1718 
1719 /*
1720  * handle all the irqs defined by the HDRC core. for now we expect:  other
1721  * irq sources (phy, dma, etc) will be handled first, musb->int_* values
1722  * will be assigned, and the irq will already have been acked.
1723  *
1724  * called in irq context with spinlock held, irqs blocked
1725  */
1726 irqreturn_t musb_interrupt(struct musb *musb)
1727 {
1728 	irqreturn_t	retval = IRQ_NONE;
1729 	unsigned long	status;
1730 	unsigned long	epnum;
1731 	u8		devctl;
1732 
1733 	if (!musb->int_usb && !musb->int_tx && !musb->int_rx)
1734 		return IRQ_NONE;
1735 
1736 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
1737 
1738 	trace_musb_isr(musb);
1739 
1740 	/**
1741 	 * According to Mentor Graphics' documentation, flowchart on page 98,
1742 	 * IRQ should be handled as follows:
1743 	 *
1744 	 * . Resume IRQ
1745 	 * . Session Request IRQ
1746 	 * . VBUS Error IRQ
1747 	 * . Suspend IRQ
1748 	 * . Connect IRQ
1749 	 * . Disconnect IRQ
1750 	 * . Reset/Babble IRQ
1751 	 * . SOF IRQ (we're not using this one)
1752 	 * . Endpoint 0 IRQ
1753 	 * . TX Endpoints
1754 	 * . RX Endpoints
1755 	 *
1756 	 * We will be following that flowchart in order to avoid any problems
1757 	 * that might arise with internal Finite State Machine.
1758 	 */
1759 
1760 	if (musb->int_usb)
1761 		retval |= musb_stage0_irq(musb, musb->int_usb, devctl);
1762 
1763 	if (musb->int_tx & 1) {
1764 		if (is_host_active(musb))
1765 			retval |= musb_h_ep0_irq(musb);
1766 		else
1767 			retval |= musb_g_ep0_irq(musb);
1768 
1769 		/* we have just handled endpoint 0 IRQ, clear it */
1770 		musb->int_tx &= ~BIT(0);
1771 	}
1772 
1773 	status = musb->int_tx;
1774 
1775 	for_each_set_bit(epnum, &status, 16) {
1776 		retval = IRQ_HANDLED;
1777 		if (is_host_active(musb))
1778 			musb_host_tx(musb, epnum);
1779 		else
1780 			musb_g_tx(musb, epnum);
1781 	}
1782 
1783 	status = musb->int_rx;
1784 
1785 	for_each_set_bit(epnum, &status, 16) {
1786 		retval = IRQ_HANDLED;
1787 		if (is_host_active(musb))
1788 			musb_host_rx(musb, epnum);
1789 		else
1790 			musb_g_rx(musb, epnum);
1791 	}
1792 
1793 	return retval;
1794 }
1795 EXPORT_SYMBOL_GPL(musb_interrupt);
1796 
1797 #ifndef CONFIG_MUSB_PIO_ONLY
1798 static bool use_dma = true;
1799 
1800 /* "modprobe ... use_dma=0" etc */
1801 module_param(use_dma, bool, 0644);
1802 MODULE_PARM_DESC(use_dma, "enable/disable use of DMA");
1803 
1804 void musb_dma_completion(struct musb *musb, u8 epnum, u8 transmit)
1805 {
1806 	/* called with controller lock already held */
1807 
1808 	if (!epnum) {
1809 		if (!is_cppi_enabled(musb)) {
1810 			/* endpoint 0 */
1811 			if (is_host_active(musb))
1812 				musb_h_ep0_irq(musb);
1813 			else
1814 				musb_g_ep0_irq(musb);
1815 		}
1816 	} else {
1817 		/* endpoints 1..15 */
1818 		if (transmit) {
1819 			if (is_host_active(musb))
1820 				musb_host_tx(musb, epnum);
1821 			else
1822 				musb_g_tx(musb, epnum);
1823 		} else {
1824 			/* receive */
1825 			if (is_host_active(musb))
1826 				musb_host_rx(musb, epnum);
1827 			else
1828 				musb_g_rx(musb, epnum);
1829 		}
1830 	}
1831 }
1832 EXPORT_SYMBOL_GPL(musb_dma_completion);
1833 
1834 #else
1835 #define use_dma			0
1836 #endif
1837 
1838 static int (*musb_phy_callback)(enum musb_vbus_id_status status);
1839 
1840 /*
1841  * musb_mailbox - optional phy notifier function
1842  * @status phy state change
1843  *
1844  * Optionally gets called from the USB PHY. Note that the USB PHY must be
1845  * disabled at the point the phy_callback is registered or unregistered.
1846  */
1847 int musb_mailbox(enum musb_vbus_id_status status)
1848 {
1849 	if (musb_phy_callback)
1850 		return musb_phy_callback(status);
1851 
1852 	return -ENODEV;
1853 };
1854 EXPORT_SYMBOL_GPL(musb_mailbox);
1855 
1856 /*-------------------------------------------------------------------------*/
1857 
1858 static ssize_t
1859 mode_show(struct device *dev, struct device_attribute *attr, char *buf)
1860 {
1861 	struct musb *musb = dev_to_musb(dev);
1862 	unsigned long flags;
1863 	int ret;
1864 
1865 	spin_lock_irqsave(&musb->lock, flags);
1866 	ret = sprintf(buf, "%s\n", usb_otg_state_string(musb->xceiv->otg->state));
1867 	spin_unlock_irqrestore(&musb->lock, flags);
1868 
1869 	return ret;
1870 }
1871 
1872 static ssize_t
1873 mode_store(struct device *dev, struct device_attribute *attr,
1874 		const char *buf, size_t n)
1875 {
1876 	struct musb	*musb = dev_to_musb(dev);
1877 	unsigned long	flags;
1878 	int		status;
1879 
1880 	spin_lock_irqsave(&musb->lock, flags);
1881 	if (sysfs_streq(buf, "host"))
1882 		status = musb_platform_set_mode(musb, MUSB_HOST);
1883 	else if (sysfs_streq(buf, "peripheral"))
1884 		status = musb_platform_set_mode(musb, MUSB_PERIPHERAL);
1885 	else if (sysfs_streq(buf, "otg"))
1886 		status = musb_platform_set_mode(musb, MUSB_OTG);
1887 	else
1888 		status = -EINVAL;
1889 	spin_unlock_irqrestore(&musb->lock, flags);
1890 
1891 	return (status == 0) ? n : status;
1892 }
1893 static DEVICE_ATTR_RW(mode);
1894 
1895 static ssize_t
1896 vbus_store(struct device *dev, struct device_attribute *attr,
1897 		const char *buf, size_t n)
1898 {
1899 	struct musb	*musb = dev_to_musb(dev);
1900 	unsigned long	flags;
1901 	unsigned long	val;
1902 
1903 	if (sscanf(buf, "%lu", &val) < 1) {
1904 		dev_err(dev, "Invalid VBUS timeout ms value\n");
1905 		return -EINVAL;
1906 	}
1907 
1908 	spin_lock_irqsave(&musb->lock, flags);
1909 	/* force T(a_wait_bcon) to be zero/unlimited *OR* valid */
1910 	musb->a_wait_bcon = val ? max_t(int, val, OTG_TIME_A_WAIT_BCON) : 0 ;
1911 	if (musb->xceiv->otg->state == OTG_STATE_A_WAIT_BCON)
1912 		musb->is_active = 0;
1913 	musb_platform_try_idle(musb, jiffies + msecs_to_jiffies(val));
1914 	spin_unlock_irqrestore(&musb->lock, flags);
1915 
1916 	return n;
1917 }
1918 
1919 static ssize_t
1920 vbus_show(struct device *dev, struct device_attribute *attr, char *buf)
1921 {
1922 	struct musb	*musb = dev_to_musb(dev);
1923 	unsigned long	flags;
1924 	unsigned long	val;
1925 	int		vbus;
1926 	u8		devctl;
1927 
1928 	pm_runtime_get_sync(dev);
1929 	spin_lock_irqsave(&musb->lock, flags);
1930 	val = musb->a_wait_bcon;
1931 	vbus = musb_platform_get_vbus_status(musb);
1932 	if (vbus < 0) {
1933 		/* Use default MUSB method by means of DEVCTL register */
1934 		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
1935 		if ((devctl & MUSB_DEVCTL_VBUS)
1936 				== (3 << MUSB_DEVCTL_VBUS_SHIFT))
1937 			vbus = 1;
1938 		else
1939 			vbus = 0;
1940 	}
1941 	spin_unlock_irqrestore(&musb->lock, flags);
1942 	pm_runtime_put_sync(dev);
1943 
1944 	return sprintf(buf, "Vbus %s, timeout %lu msec\n",
1945 			vbus ? "on" : "off", val);
1946 }
1947 static DEVICE_ATTR_RW(vbus);
1948 
1949 /* Gadget drivers can't know that a host is connected so they might want
1950  * to start SRP, but users can.  This allows userspace to trigger SRP.
1951  */
1952 static ssize_t srp_store(struct device *dev, struct device_attribute *attr,
1953 		const char *buf, size_t n)
1954 {
1955 	struct musb	*musb = dev_to_musb(dev);
1956 	unsigned short	srp;
1957 
1958 	if (sscanf(buf, "%hu", &srp) != 1
1959 			|| (srp != 1)) {
1960 		dev_err(dev, "SRP: Value must be 1\n");
1961 		return -EINVAL;
1962 	}
1963 
1964 	if (srp == 1)
1965 		musb_g_wakeup(musb);
1966 
1967 	return n;
1968 }
1969 static DEVICE_ATTR_WO(srp);
1970 
1971 static struct attribute *musb_attrs[] = {
1972 	&dev_attr_mode.attr,
1973 	&dev_attr_vbus.attr,
1974 	&dev_attr_srp.attr,
1975 	NULL
1976 };
1977 ATTRIBUTE_GROUPS(musb);
1978 
1979 #define MUSB_QUIRK_B_INVALID_VBUS_91	(MUSB_DEVCTL_BDEVICE | \
1980 					 (2 << MUSB_DEVCTL_VBUS_SHIFT) | \
1981 					 MUSB_DEVCTL_SESSION)
1982 #define MUSB_QUIRK_B_DISCONNECT_99	(MUSB_DEVCTL_BDEVICE | \
1983 					 (3 << MUSB_DEVCTL_VBUS_SHIFT) | \
1984 					 MUSB_DEVCTL_SESSION)
1985 #define MUSB_QUIRK_A_DISCONNECT_19	((3 << MUSB_DEVCTL_VBUS_SHIFT) | \
1986 					 MUSB_DEVCTL_SESSION)
1987 
1988 static bool musb_state_needs_recheck(struct musb *musb, u8 devctl,
1989 				     const char *desc)
1990 {
1991 	if (musb->quirk_retries && !musb->flush_irq_work) {
1992 		trace_musb_state(musb, devctl, desc);
1993 		schedule_delayed_work(&musb->irq_work,
1994 				      msecs_to_jiffies(1000));
1995 		musb->quirk_retries--;
1996 
1997 		return true;
1998 	}
1999 
2000 	return false;
2001 }
2002 
2003 /*
2004  * Check the musb devctl session bit to determine if we want to
2005  * allow PM runtime for the device. In general, we want to keep things
2006  * active when the session bit is set except after host disconnect.
2007  *
2008  * Only called from musb_irq_work. If this ever needs to get called
2009  * elsewhere, proper locking must be implemented for musb->session.
2010  */
2011 static void musb_pm_runtime_check_session(struct musb *musb)
2012 {
2013 	u8 devctl, s;
2014 	int error;
2015 
2016 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2017 
2018 	/* Handle session status quirks first */
2019 	s = MUSB_DEVCTL_FSDEV | MUSB_DEVCTL_LSDEV |
2020 		MUSB_DEVCTL_HR;
2021 	switch (devctl & ~s) {
2022 	case MUSB_QUIRK_B_DISCONNECT_99:
2023 		musb_state_needs_recheck(musb, devctl,
2024 			"Poll devctl in case of suspend after disconnect");
2025 		break;
2026 	case MUSB_QUIRK_B_INVALID_VBUS_91:
2027 		if (musb_state_needs_recheck(musb, devctl,
2028 				"Poll devctl on invalid vbus, assume no session"))
2029 			return;
2030 		fallthrough;
2031 	case MUSB_QUIRK_A_DISCONNECT_19:
2032 		if (musb_state_needs_recheck(musb, devctl,
2033 				"Poll devctl on possible host mode disconnect"))
2034 			return;
2035 		if (!musb->session)
2036 			break;
2037 		trace_musb_state(musb, devctl, "Allow PM on possible host mode disconnect");
2038 		pm_runtime_mark_last_busy(musb->controller);
2039 		pm_runtime_put_autosuspend(musb->controller);
2040 		musb->session = false;
2041 		return;
2042 	default:
2043 		break;
2044 	}
2045 
2046 	/* No need to do anything if session has not changed */
2047 	s = devctl & MUSB_DEVCTL_SESSION;
2048 	if (s == musb->session)
2049 		return;
2050 
2051 	/* Block PM or allow PM? */
2052 	if (s) {
2053 		trace_musb_state(musb, devctl, "Block PM on active session");
2054 		error = pm_runtime_get_sync(musb->controller);
2055 		if (error < 0)
2056 			dev_err(musb->controller, "Could not enable: %i\n",
2057 				error);
2058 		musb->quirk_retries = 3;
2059 
2060 		/*
2061 		 * We can get a spurious MUSB_INTR_SESSREQ interrupt on start-up
2062 		 * in B-peripheral mode with nothing connected and the session
2063 		 * bit clears silently. Check status again in 3 seconds.
2064 		 */
2065 		if (devctl & MUSB_DEVCTL_BDEVICE)
2066 			schedule_delayed_work(&musb->irq_work,
2067 					      msecs_to_jiffies(3000));
2068 	} else {
2069 		trace_musb_state(musb, devctl, "Allow PM with no session");
2070 		pm_runtime_mark_last_busy(musb->controller);
2071 		pm_runtime_put_autosuspend(musb->controller);
2072 	}
2073 
2074 	musb->session = s;
2075 }
2076 
2077 /* Only used to provide driver mode change events */
2078 static void musb_irq_work(struct work_struct *data)
2079 {
2080 	struct musb *musb = container_of(data, struct musb, irq_work.work);
2081 	int error;
2082 
2083 	error = pm_runtime_resume_and_get(musb->controller);
2084 	if (error < 0) {
2085 		dev_err(musb->controller, "Could not enable: %i\n", error);
2086 
2087 		return;
2088 	}
2089 
2090 	musb_pm_runtime_check_session(musb);
2091 
2092 	if (musb->xceiv->otg->state != musb->xceiv_old_state) {
2093 		musb->xceiv_old_state = musb->xceiv->otg->state;
2094 		sysfs_notify(&musb->controller->kobj, NULL, "mode");
2095 	}
2096 
2097 	pm_runtime_mark_last_busy(musb->controller);
2098 	pm_runtime_put_autosuspend(musb->controller);
2099 }
2100 
2101 static void musb_recover_from_babble(struct musb *musb)
2102 {
2103 	int ret;
2104 	u8 devctl;
2105 
2106 	musb_disable_interrupts(musb);
2107 
2108 	/*
2109 	 * wait at least 320 cycles of 60MHz clock. That's 5.3us, we will give
2110 	 * it some slack and wait for 10us.
2111 	 */
2112 	udelay(10);
2113 
2114 	ret  = musb_platform_recover(musb);
2115 	if (ret) {
2116 		musb_enable_interrupts(musb);
2117 		return;
2118 	}
2119 
2120 	/* drop session bit */
2121 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2122 	devctl &= ~MUSB_DEVCTL_SESSION;
2123 	musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
2124 
2125 	/* tell usbcore about it */
2126 	musb_root_disconnect(musb);
2127 
2128 	/*
2129 	 * When a babble condition occurs, the musb controller
2130 	 * removes the session bit and the endpoint config is lost.
2131 	 */
2132 	if (musb->dyn_fifo)
2133 		ret = ep_config_from_table(musb);
2134 	else
2135 		ret = ep_config_from_hw(musb);
2136 
2137 	/* restart session */
2138 	if (ret == 0)
2139 		musb_start(musb);
2140 }
2141 
2142 /* --------------------------------------------------------------------------
2143  * Init support
2144  */
2145 
2146 static struct musb *allocate_instance(struct device *dev,
2147 		const struct musb_hdrc_config *config, void __iomem *mbase)
2148 {
2149 	struct musb		*musb;
2150 	struct musb_hw_ep	*ep;
2151 	int			epnum;
2152 	int			ret;
2153 
2154 	musb = devm_kzalloc(dev, sizeof(*musb), GFP_KERNEL);
2155 	if (!musb)
2156 		return NULL;
2157 
2158 	INIT_LIST_HEAD(&musb->control);
2159 	INIT_LIST_HEAD(&musb->in_bulk);
2160 	INIT_LIST_HEAD(&musb->out_bulk);
2161 	INIT_LIST_HEAD(&musb->pending_list);
2162 
2163 	musb->vbuserr_retry = VBUSERR_RETRY_COUNT;
2164 	musb->a_wait_bcon = OTG_TIME_A_WAIT_BCON;
2165 	musb->mregs = mbase;
2166 	musb->ctrl_base = mbase;
2167 	musb->nIrq = -ENODEV;
2168 	musb->config = config;
2169 	BUG_ON(musb->config->num_eps > MUSB_C_NUM_EPS);
2170 	for (epnum = 0, ep = musb->endpoints;
2171 			epnum < musb->config->num_eps;
2172 			epnum++, ep++) {
2173 		ep->musb = musb;
2174 		ep->epnum = epnum;
2175 	}
2176 
2177 	musb->controller = dev;
2178 
2179 	ret = musb_host_alloc(musb);
2180 	if (ret < 0)
2181 		goto err_free;
2182 
2183 	dev_set_drvdata(dev, musb);
2184 
2185 	return musb;
2186 
2187 err_free:
2188 	return NULL;
2189 }
2190 
2191 static void musb_free(struct musb *musb)
2192 {
2193 	/* this has multiple entry modes. it handles fault cleanup after
2194 	 * probe(), where things may be partially set up, as well as rmmod
2195 	 * cleanup after everything's been de-activated.
2196 	 */
2197 
2198 	if (musb->nIrq >= 0) {
2199 		if (musb->irq_wake)
2200 			disable_irq_wake(musb->nIrq);
2201 		free_irq(musb->nIrq, musb);
2202 	}
2203 
2204 	musb_host_free(musb);
2205 }
2206 
2207 struct musb_pending_work {
2208 	int (*callback)(struct musb *musb, void *data);
2209 	void *data;
2210 	struct list_head node;
2211 };
2212 
2213 #ifdef CONFIG_PM
2214 /*
2215  * Called from musb_runtime_resume(), musb_resume(), and
2216  * musb_queue_resume_work(). Callers must take musb->lock.
2217  */
2218 static int musb_run_resume_work(struct musb *musb)
2219 {
2220 	struct musb_pending_work *w, *_w;
2221 	unsigned long flags;
2222 	int error = 0;
2223 
2224 	spin_lock_irqsave(&musb->list_lock, flags);
2225 	list_for_each_entry_safe(w, _w, &musb->pending_list, node) {
2226 		if (w->callback) {
2227 			error = w->callback(musb, w->data);
2228 			if (error < 0) {
2229 				dev_err(musb->controller,
2230 					"resume callback %p failed: %i\n",
2231 					w->callback, error);
2232 			}
2233 		}
2234 		list_del(&w->node);
2235 		devm_kfree(musb->controller, w);
2236 	}
2237 	spin_unlock_irqrestore(&musb->list_lock, flags);
2238 
2239 	return error;
2240 }
2241 #endif
2242 
2243 /*
2244  * Called to run work if device is active or else queue the work to happen
2245  * on resume. Caller must take musb->lock and must hold an RPM reference.
2246  *
2247  * Note that we cowardly refuse queuing work after musb PM runtime
2248  * resume is done calling musb_run_resume_work() and return -EINPROGRESS
2249  * instead.
2250  */
2251 int musb_queue_resume_work(struct musb *musb,
2252 			   int (*callback)(struct musb *musb, void *data),
2253 			   void *data)
2254 {
2255 	struct musb_pending_work *w;
2256 	unsigned long flags;
2257 	bool is_suspended;
2258 	int error;
2259 
2260 	if (WARN_ON(!callback))
2261 		return -EINVAL;
2262 
2263 	spin_lock_irqsave(&musb->list_lock, flags);
2264 	is_suspended = musb->is_runtime_suspended;
2265 
2266 	if (is_suspended) {
2267 		w = devm_kzalloc(musb->controller, sizeof(*w), GFP_ATOMIC);
2268 		if (!w) {
2269 			error = -ENOMEM;
2270 			goto out_unlock;
2271 		}
2272 
2273 		w->callback = callback;
2274 		w->data = data;
2275 
2276 		list_add_tail(&w->node, &musb->pending_list);
2277 		error = 0;
2278 	}
2279 
2280 out_unlock:
2281 	spin_unlock_irqrestore(&musb->list_lock, flags);
2282 
2283 	if (!is_suspended)
2284 		error = callback(musb, data);
2285 
2286 	return error;
2287 }
2288 EXPORT_SYMBOL_GPL(musb_queue_resume_work);
2289 
2290 static void musb_deassert_reset(struct work_struct *work)
2291 {
2292 	struct musb *musb;
2293 	unsigned long flags;
2294 
2295 	musb = container_of(work, struct musb, deassert_reset_work.work);
2296 
2297 	spin_lock_irqsave(&musb->lock, flags);
2298 
2299 	if (musb->port1_status & USB_PORT_STAT_RESET)
2300 		musb_port_reset(musb, false);
2301 
2302 	spin_unlock_irqrestore(&musb->lock, flags);
2303 }
2304 
2305 /*
2306  * Perform generic per-controller initialization.
2307  *
2308  * @dev: the controller (already clocked, etc)
2309  * @nIrq: IRQ number
2310  * @ctrl: virtual address of controller registers,
2311  *	not yet corrected for platform-specific offsets
2312  */
2313 static int
2314 musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
2315 {
2316 	int			status;
2317 	struct musb		*musb;
2318 	struct musb_hdrc_platform_data *plat = dev_get_platdata(dev);
2319 
2320 	/* The driver might handle more features than the board; OK.
2321 	 * Fail when the board needs a feature that's not enabled.
2322 	 */
2323 	if (!plat) {
2324 		dev_err(dev, "no platform_data?\n");
2325 		status = -ENODEV;
2326 		goto fail0;
2327 	}
2328 
2329 	/* allocate */
2330 	musb = allocate_instance(dev, plat->config, ctrl);
2331 	if (!musb) {
2332 		status = -ENOMEM;
2333 		goto fail0;
2334 	}
2335 
2336 	spin_lock_init(&musb->lock);
2337 	spin_lock_init(&musb->list_lock);
2338 	musb->board_set_power = plat->set_power;
2339 	musb->min_power = plat->min_power;
2340 	musb->ops = plat->platform_ops;
2341 	musb->port_mode = plat->mode;
2342 
2343 	/*
2344 	 * Initialize the default IO functions. At least omap2430 needs
2345 	 * these early. We initialize the platform specific IO functions
2346 	 * later on.
2347 	 */
2348 	musb_readb = musb_default_readb;
2349 	musb_writeb = musb_default_writeb;
2350 	musb_readw = musb_default_readw;
2351 	musb_writew = musb_default_writew;
2352 
2353 	/* The musb_platform_init() call:
2354 	 *   - adjusts musb->mregs
2355 	 *   - sets the musb->isr
2356 	 *   - may initialize an integrated transceiver
2357 	 *   - initializes musb->xceiv, usually by otg_get_phy()
2358 	 *   - stops powering VBUS
2359 	 *
2360 	 * There are various transceiver configurations.
2361 	 * DaVinci, TUSB60x0, and others integrate them.  OMAP3 uses
2362 	 * external/discrete ones in various flavors (twl4030 family,
2363 	 * isp1504, non-OTG, etc) mostly hooking up through ULPI.
2364 	 */
2365 	status = musb_platform_init(musb);
2366 	if (status < 0)
2367 		goto fail1;
2368 
2369 	if (!musb->isr) {
2370 		status = -ENODEV;
2371 		goto fail2;
2372 	}
2373 
2374 
2375 	/* Most devices use indexed offset or flat offset */
2376 	if (musb->ops->quirks & MUSB_INDEXED_EP) {
2377 		musb->io.ep_offset = musb_indexed_ep_offset;
2378 		musb->io.ep_select = musb_indexed_ep_select;
2379 	} else {
2380 		musb->io.ep_offset = musb_flat_ep_offset;
2381 		musb->io.ep_select = musb_flat_ep_select;
2382 	}
2383 
2384 	if (musb->ops->quirks & MUSB_G_NO_SKB_RESERVE)
2385 		musb->g.quirk_avoids_skb_reserve = 1;
2386 
2387 	/* At least tusb6010 has its own offsets */
2388 	if (musb->ops->ep_offset)
2389 		musb->io.ep_offset = musb->ops->ep_offset;
2390 	if (musb->ops->ep_select)
2391 		musb->io.ep_select = musb->ops->ep_select;
2392 
2393 	if (musb->ops->fifo_mode)
2394 		fifo_mode = musb->ops->fifo_mode;
2395 	else
2396 		fifo_mode = 4;
2397 
2398 	if (musb->ops->fifo_offset)
2399 		musb->io.fifo_offset = musb->ops->fifo_offset;
2400 	else
2401 		musb->io.fifo_offset = musb_default_fifo_offset;
2402 
2403 	if (musb->ops->busctl_offset)
2404 		musb->io.busctl_offset = musb->ops->busctl_offset;
2405 	else
2406 		musb->io.busctl_offset = musb_default_busctl_offset;
2407 
2408 	if (musb->ops->readb)
2409 		musb_readb = musb->ops->readb;
2410 	if (musb->ops->writeb)
2411 		musb_writeb = musb->ops->writeb;
2412 	if (musb->ops->clearb)
2413 		musb_clearb = musb->ops->clearb;
2414 	else
2415 		musb_clearb = musb_readb;
2416 
2417 	if (musb->ops->readw)
2418 		musb_readw = musb->ops->readw;
2419 	if (musb->ops->writew)
2420 		musb_writew = musb->ops->writew;
2421 	if (musb->ops->clearw)
2422 		musb_clearw = musb->ops->clearw;
2423 	else
2424 		musb_clearw = musb_readw;
2425 
2426 #ifndef CONFIG_MUSB_PIO_ONLY
2427 	if (!musb->ops->dma_init || !musb->ops->dma_exit) {
2428 		dev_err(dev, "DMA controller not set\n");
2429 		status = -ENODEV;
2430 		goto fail2;
2431 	}
2432 	musb_dma_controller_create = musb->ops->dma_init;
2433 	musb_dma_controller_destroy = musb->ops->dma_exit;
2434 #endif
2435 
2436 	if (musb->ops->read_fifo)
2437 		musb->io.read_fifo = musb->ops->read_fifo;
2438 	else
2439 		musb->io.read_fifo = musb_default_read_fifo;
2440 
2441 	if (musb->ops->write_fifo)
2442 		musb->io.write_fifo = musb->ops->write_fifo;
2443 	else
2444 		musb->io.write_fifo = musb_default_write_fifo;
2445 
2446 	if (musb->ops->get_toggle)
2447 		musb->io.get_toggle = musb->ops->get_toggle;
2448 	else
2449 		musb->io.get_toggle = musb_default_get_toggle;
2450 
2451 	if (musb->ops->set_toggle)
2452 		musb->io.set_toggle = musb->ops->set_toggle;
2453 	else
2454 		musb->io.set_toggle = musb_default_set_toggle;
2455 
2456 	if (!musb->xceiv->io_ops) {
2457 		musb->xceiv->io_dev = musb->controller;
2458 		musb->xceiv->io_priv = musb->mregs;
2459 		musb->xceiv->io_ops = &musb_ulpi_access;
2460 	}
2461 
2462 	if (musb->ops->phy_callback)
2463 		musb_phy_callback = musb->ops->phy_callback;
2464 
2465 	/*
2466 	 * We need musb_read/write functions initialized for PM.
2467 	 * Note that at least 2430 glue needs autosuspend delay
2468 	 * somewhere above 300 ms for the hardware to idle properly
2469 	 * after disconnecting the cable in host mode. Let's use
2470 	 * 500 ms for some margin.
2471 	 */
2472 	pm_runtime_use_autosuspend(musb->controller);
2473 	pm_runtime_set_autosuspend_delay(musb->controller, 500);
2474 	pm_runtime_enable(musb->controller);
2475 	pm_runtime_get_sync(musb->controller);
2476 
2477 	status = usb_phy_init(musb->xceiv);
2478 	if (status < 0)
2479 		goto err_usb_phy_init;
2480 
2481 	if (use_dma && dev->dma_mask) {
2482 		musb->dma_controller =
2483 			musb_dma_controller_create(musb, musb->mregs);
2484 		if (IS_ERR(musb->dma_controller)) {
2485 			status = PTR_ERR(musb->dma_controller);
2486 			goto fail2_5;
2487 		}
2488 	}
2489 
2490 	/* be sure interrupts are disabled before connecting ISR */
2491 	musb_platform_disable(musb);
2492 	musb_disable_interrupts(musb);
2493 	musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
2494 
2495 	/* MUSB_POWER_SOFTCONN might be already set, JZ4740 does this. */
2496 	musb_writeb(musb->mregs, MUSB_POWER, 0);
2497 
2498 	/* Init IRQ workqueue before request_irq */
2499 	INIT_DELAYED_WORK(&musb->irq_work, musb_irq_work);
2500 	INIT_DELAYED_WORK(&musb->deassert_reset_work, musb_deassert_reset);
2501 	INIT_DELAYED_WORK(&musb->finish_resume_work, musb_host_finish_resume);
2502 
2503 	/* setup musb parts of the core (especially endpoints) */
2504 	status = musb_core_init(plat->config->multipoint
2505 			? MUSB_CONTROLLER_MHDRC
2506 			: MUSB_CONTROLLER_HDRC, musb);
2507 	if (status < 0)
2508 		goto fail3;
2509 
2510 	timer_setup(&musb->otg_timer, musb_otg_timer_func, 0);
2511 
2512 	/* attach to the IRQ */
2513 	if (request_irq(nIrq, musb->isr, IRQF_SHARED, dev_name(dev), musb)) {
2514 		dev_err(dev, "request_irq %d failed!\n", nIrq);
2515 		status = -ENODEV;
2516 		goto fail3;
2517 	}
2518 	musb->nIrq = nIrq;
2519 	/* FIXME this handles wakeup irqs wrong */
2520 	if (enable_irq_wake(nIrq) == 0) {
2521 		musb->irq_wake = 1;
2522 		device_init_wakeup(dev, 1);
2523 	} else {
2524 		musb->irq_wake = 0;
2525 	}
2526 
2527 	/* program PHY to use external vBus if required */
2528 	if (plat->extvbus) {
2529 		u8 busctl = musb_readb(musb->mregs, MUSB_ULPI_BUSCONTROL);
2530 		busctl |= MUSB_ULPI_USE_EXTVBUS;
2531 		musb_writeb(musb->mregs, MUSB_ULPI_BUSCONTROL, busctl);
2532 	}
2533 
2534 	MUSB_DEV_MODE(musb);
2535 	musb->xceiv->otg->state = OTG_STATE_B_IDLE;
2536 
2537 	switch (musb->port_mode) {
2538 	case MUSB_HOST:
2539 		status = musb_host_setup(musb, plat->power);
2540 		if (status < 0)
2541 			goto fail3;
2542 		status = musb_platform_set_mode(musb, MUSB_HOST);
2543 		break;
2544 	case MUSB_PERIPHERAL:
2545 		status = musb_gadget_setup(musb);
2546 		if (status < 0)
2547 			goto fail3;
2548 		status = musb_platform_set_mode(musb, MUSB_PERIPHERAL);
2549 		break;
2550 	case MUSB_OTG:
2551 		status = musb_host_setup(musb, plat->power);
2552 		if (status < 0)
2553 			goto fail3;
2554 		status = musb_gadget_setup(musb);
2555 		if (status) {
2556 			musb_host_cleanup(musb);
2557 			goto fail3;
2558 		}
2559 		status = musb_platform_set_mode(musb, MUSB_OTG);
2560 		break;
2561 	default:
2562 		dev_err(dev, "unsupported port mode %d\n", musb->port_mode);
2563 		break;
2564 	}
2565 
2566 	if (status < 0)
2567 		goto fail3;
2568 
2569 	musb_init_debugfs(musb);
2570 
2571 	musb->is_initialized = 1;
2572 	pm_runtime_mark_last_busy(musb->controller);
2573 	pm_runtime_put_autosuspend(musb->controller);
2574 
2575 	return 0;
2576 
2577 fail3:
2578 	cancel_delayed_work_sync(&musb->irq_work);
2579 	cancel_delayed_work_sync(&musb->finish_resume_work);
2580 	cancel_delayed_work_sync(&musb->deassert_reset_work);
2581 	if (musb->dma_controller)
2582 		musb_dma_controller_destroy(musb->dma_controller);
2583 
2584 fail2_5:
2585 	usb_phy_shutdown(musb->xceiv);
2586 
2587 err_usb_phy_init:
2588 	pm_runtime_dont_use_autosuspend(musb->controller);
2589 	pm_runtime_put_sync(musb->controller);
2590 	pm_runtime_disable(musb->controller);
2591 
2592 fail2:
2593 	if (musb->irq_wake)
2594 		device_init_wakeup(dev, 0);
2595 	musb_platform_exit(musb);
2596 
2597 fail1:
2598 	dev_err_probe(musb->controller, status, "%s failed\n", __func__);
2599 
2600 	musb_free(musb);
2601 
2602 fail0:
2603 
2604 	return status;
2605 
2606 }
2607 
2608 /*-------------------------------------------------------------------------*/
2609 
2610 /* all implementations (PCI bridge to FPGA, VLYNQ, etc) should just
2611  * bridge to a platform device; this driver then suffices.
2612  */
2613 static int musb_probe(struct platform_device *pdev)
2614 {
2615 	struct device	*dev = &pdev->dev;
2616 	int		irq = platform_get_irq_byname(pdev, "mc");
2617 	void __iomem	*base;
2618 
2619 	if (irq <= 0)
2620 		return -ENODEV;
2621 
2622 	base = devm_platform_ioremap_resource(pdev, 0);
2623 	if (IS_ERR(base))
2624 		return PTR_ERR(base);
2625 
2626 	return musb_init_controller(dev, irq, base);
2627 }
2628 
2629 static int musb_remove(struct platform_device *pdev)
2630 {
2631 	struct device	*dev = &pdev->dev;
2632 	struct musb	*musb = dev_to_musb(dev);
2633 	unsigned long	flags;
2634 
2635 	/* this gets called on rmmod.
2636 	 *  - Host mode: host may still be active
2637 	 *  - Peripheral mode: peripheral is deactivated (or never-activated)
2638 	 *  - OTG mode: both roles are deactivated (or never-activated)
2639 	 */
2640 	musb_exit_debugfs(musb);
2641 
2642 	cancel_delayed_work_sync(&musb->irq_work);
2643 	cancel_delayed_work_sync(&musb->finish_resume_work);
2644 	cancel_delayed_work_sync(&musb->deassert_reset_work);
2645 	pm_runtime_get_sync(musb->controller);
2646 	musb_host_cleanup(musb);
2647 	musb_gadget_cleanup(musb);
2648 
2649 	musb_platform_disable(musb);
2650 	spin_lock_irqsave(&musb->lock, flags);
2651 	musb_disable_interrupts(musb);
2652 	musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
2653 	spin_unlock_irqrestore(&musb->lock, flags);
2654 	musb_platform_exit(musb);
2655 
2656 	pm_runtime_dont_use_autosuspend(musb->controller);
2657 	pm_runtime_put_sync(musb->controller);
2658 	pm_runtime_disable(musb->controller);
2659 	musb_phy_callback = NULL;
2660 	if (musb->dma_controller)
2661 		musb_dma_controller_destroy(musb->dma_controller);
2662 	usb_phy_shutdown(musb->xceiv);
2663 	musb_free(musb);
2664 	device_init_wakeup(dev, 0);
2665 	return 0;
2666 }
2667 
2668 #ifdef	CONFIG_PM
2669 
2670 static void musb_save_context(struct musb *musb)
2671 {
2672 	int i;
2673 	void __iomem *musb_base = musb->mregs;
2674 	void __iomem *epio;
2675 
2676 	musb->context.frame = musb_readw(musb_base, MUSB_FRAME);
2677 	musb->context.testmode = musb_readb(musb_base, MUSB_TESTMODE);
2678 	musb->context.busctl = musb_readb(musb_base, MUSB_ULPI_BUSCONTROL);
2679 	musb->context.power = musb_readb(musb_base, MUSB_POWER);
2680 	musb->context.intrusbe = musb_readb(musb_base, MUSB_INTRUSBE);
2681 	musb->context.index = musb_readb(musb_base, MUSB_INDEX);
2682 	musb->context.devctl = musb_readb(musb_base, MUSB_DEVCTL);
2683 
2684 	for (i = 0; i < musb->config->num_eps; ++i) {
2685 		epio = musb->endpoints[i].regs;
2686 		if (!epio)
2687 			continue;
2688 
2689 		musb_writeb(musb_base, MUSB_INDEX, i);
2690 		musb->context.index_regs[i].txmaxp =
2691 			musb_readw(epio, MUSB_TXMAXP);
2692 		musb->context.index_regs[i].txcsr =
2693 			musb_readw(epio, MUSB_TXCSR);
2694 		musb->context.index_regs[i].rxmaxp =
2695 			musb_readw(epio, MUSB_RXMAXP);
2696 		musb->context.index_regs[i].rxcsr =
2697 			musb_readw(epio, MUSB_RXCSR);
2698 
2699 		if (musb->dyn_fifo) {
2700 			musb->context.index_regs[i].txfifoadd =
2701 					musb_readw(musb_base, MUSB_TXFIFOADD);
2702 			musb->context.index_regs[i].rxfifoadd =
2703 					musb_readw(musb_base, MUSB_RXFIFOADD);
2704 			musb->context.index_regs[i].txfifosz =
2705 					musb_readb(musb_base, MUSB_TXFIFOSZ);
2706 			musb->context.index_regs[i].rxfifosz =
2707 					musb_readb(musb_base, MUSB_RXFIFOSZ);
2708 		}
2709 
2710 		musb->context.index_regs[i].txtype =
2711 			musb_readb(epio, MUSB_TXTYPE);
2712 		musb->context.index_regs[i].txinterval =
2713 			musb_readb(epio, MUSB_TXINTERVAL);
2714 		musb->context.index_regs[i].rxtype =
2715 			musb_readb(epio, MUSB_RXTYPE);
2716 		musb->context.index_regs[i].rxinterval =
2717 			musb_readb(epio, MUSB_RXINTERVAL);
2718 
2719 		musb->context.index_regs[i].txfunaddr =
2720 			musb_read_txfunaddr(musb, i);
2721 		musb->context.index_regs[i].txhubaddr =
2722 			musb_read_txhubaddr(musb, i);
2723 		musb->context.index_regs[i].txhubport =
2724 			musb_read_txhubport(musb, i);
2725 
2726 		musb->context.index_regs[i].rxfunaddr =
2727 			musb_read_rxfunaddr(musb, i);
2728 		musb->context.index_regs[i].rxhubaddr =
2729 			musb_read_rxhubaddr(musb, i);
2730 		musb->context.index_regs[i].rxhubport =
2731 			musb_read_rxhubport(musb, i);
2732 	}
2733 }
2734 
2735 static void musb_restore_context(struct musb *musb)
2736 {
2737 	int i;
2738 	void __iomem *musb_base = musb->mregs;
2739 	void __iomem *epio;
2740 	u8 power;
2741 
2742 	musb_writew(musb_base, MUSB_FRAME, musb->context.frame);
2743 	musb_writeb(musb_base, MUSB_TESTMODE, musb->context.testmode);
2744 	musb_writeb(musb_base, MUSB_ULPI_BUSCONTROL, musb->context.busctl);
2745 
2746 	/* Don't affect SUSPENDM/RESUME bits in POWER reg */
2747 	power = musb_readb(musb_base, MUSB_POWER);
2748 	power &= MUSB_POWER_SUSPENDM | MUSB_POWER_RESUME;
2749 	musb->context.power &= ~(MUSB_POWER_SUSPENDM | MUSB_POWER_RESUME);
2750 	power |= musb->context.power;
2751 	musb_writeb(musb_base, MUSB_POWER, power);
2752 
2753 	musb_writew(musb_base, MUSB_INTRTXE, musb->intrtxe);
2754 	musb_writew(musb_base, MUSB_INTRRXE, musb->intrrxe);
2755 	musb_writeb(musb_base, MUSB_INTRUSBE, musb->context.intrusbe);
2756 	if (musb->context.devctl & MUSB_DEVCTL_SESSION)
2757 		musb_writeb(musb_base, MUSB_DEVCTL, musb->context.devctl);
2758 
2759 	for (i = 0; i < musb->config->num_eps; ++i) {
2760 		epio = musb->endpoints[i].regs;
2761 		if (!epio)
2762 			continue;
2763 
2764 		musb_writeb(musb_base, MUSB_INDEX, i);
2765 		musb_writew(epio, MUSB_TXMAXP,
2766 			musb->context.index_regs[i].txmaxp);
2767 		musb_writew(epio, MUSB_TXCSR,
2768 			musb->context.index_regs[i].txcsr);
2769 		musb_writew(epio, MUSB_RXMAXP,
2770 			musb->context.index_regs[i].rxmaxp);
2771 		musb_writew(epio, MUSB_RXCSR,
2772 			musb->context.index_regs[i].rxcsr);
2773 
2774 		if (musb->dyn_fifo) {
2775 			musb_writeb(musb_base, MUSB_TXFIFOSZ,
2776 				musb->context.index_regs[i].txfifosz);
2777 			musb_writeb(musb_base, MUSB_RXFIFOSZ,
2778 				musb->context.index_regs[i].rxfifosz);
2779 			musb_writew(musb_base, MUSB_TXFIFOADD,
2780 				musb->context.index_regs[i].txfifoadd);
2781 			musb_writew(musb_base, MUSB_RXFIFOADD,
2782 				musb->context.index_regs[i].rxfifoadd);
2783 		}
2784 
2785 		musb_writeb(epio, MUSB_TXTYPE,
2786 				musb->context.index_regs[i].txtype);
2787 		musb_writeb(epio, MUSB_TXINTERVAL,
2788 				musb->context.index_regs[i].txinterval);
2789 		musb_writeb(epio, MUSB_RXTYPE,
2790 				musb->context.index_regs[i].rxtype);
2791 		musb_writeb(epio, MUSB_RXINTERVAL,
2792 
2793 				musb->context.index_regs[i].rxinterval);
2794 		musb_write_txfunaddr(musb, i,
2795 				musb->context.index_regs[i].txfunaddr);
2796 		musb_write_txhubaddr(musb, i,
2797 				musb->context.index_regs[i].txhubaddr);
2798 		musb_write_txhubport(musb, i,
2799 				musb->context.index_regs[i].txhubport);
2800 
2801 		musb_write_rxfunaddr(musb, i,
2802 				musb->context.index_regs[i].rxfunaddr);
2803 		musb_write_rxhubaddr(musb, i,
2804 				musb->context.index_regs[i].rxhubaddr);
2805 		musb_write_rxhubport(musb, i,
2806 				musb->context.index_regs[i].rxhubport);
2807 	}
2808 	musb_writeb(musb_base, MUSB_INDEX, musb->context.index);
2809 }
2810 
2811 static int musb_suspend(struct device *dev)
2812 {
2813 	struct musb	*musb = dev_to_musb(dev);
2814 	unsigned long	flags;
2815 	int ret;
2816 
2817 	ret = pm_runtime_get_sync(dev);
2818 	if (ret < 0) {
2819 		pm_runtime_put_noidle(dev);
2820 		return ret;
2821 	}
2822 
2823 	musb_platform_disable(musb);
2824 	musb_disable_interrupts(musb);
2825 
2826 	musb->flush_irq_work = true;
2827 	while (flush_delayed_work(&musb->irq_work))
2828 		;
2829 	musb->flush_irq_work = false;
2830 
2831 	if (!(musb->ops->quirks & MUSB_PRESERVE_SESSION))
2832 		musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
2833 
2834 	WARN_ON(!list_empty(&musb->pending_list));
2835 
2836 	spin_lock_irqsave(&musb->lock, flags);
2837 
2838 	if (is_peripheral_active(musb)) {
2839 		/* FIXME force disconnect unless we know USB will wake
2840 		 * the system up quickly enough to respond ...
2841 		 */
2842 	} else if (is_host_active(musb)) {
2843 		/* we know all the children are suspended; sometimes
2844 		 * they will even be wakeup-enabled.
2845 		 */
2846 	}
2847 
2848 	musb_save_context(musb);
2849 
2850 	spin_unlock_irqrestore(&musb->lock, flags);
2851 	return 0;
2852 }
2853 
2854 static int musb_resume(struct device *dev)
2855 {
2856 	struct musb *musb = dev_to_musb(dev);
2857 	unsigned long flags;
2858 	int error;
2859 	u8 devctl;
2860 	u8 mask;
2861 
2862 	/*
2863 	 * For static cmos like DaVinci, register values were preserved
2864 	 * unless for some reason the whole soc powered down or the USB
2865 	 * module got reset through the PSC (vs just being disabled).
2866 	 *
2867 	 * For the DSPS glue layer though, a full register restore has to
2868 	 * be done. As it shouldn't harm other platforms, we do it
2869 	 * unconditionally.
2870 	 */
2871 
2872 	musb_restore_context(musb);
2873 
2874 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2875 	mask = MUSB_DEVCTL_BDEVICE | MUSB_DEVCTL_FSDEV | MUSB_DEVCTL_LSDEV;
2876 	if ((devctl & mask) != (musb->context.devctl & mask))
2877 		musb->port1_status = 0;
2878 
2879 	musb_enable_interrupts(musb);
2880 	musb_platform_enable(musb);
2881 
2882 	/* session might be disabled in suspend */
2883 	if (musb->port_mode == MUSB_HOST &&
2884 	    !(musb->ops->quirks & MUSB_PRESERVE_SESSION)) {
2885 		devctl |= MUSB_DEVCTL_SESSION;
2886 		musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
2887 	}
2888 
2889 	spin_lock_irqsave(&musb->lock, flags);
2890 	error = musb_run_resume_work(musb);
2891 	if (error)
2892 		dev_err(musb->controller, "resume work failed with %i\n",
2893 			error);
2894 	spin_unlock_irqrestore(&musb->lock, flags);
2895 
2896 	pm_runtime_mark_last_busy(dev);
2897 	pm_runtime_put_autosuspend(dev);
2898 
2899 	return 0;
2900 }
2901 
2902 static int musb_runtime_suspend(struct device *dev)
2903 {
2904 	struct musb	*musb = dev_to_musb(dev);
2905 
2906 	musb_save_context(musb);
2907 	musb->is_runtime_suspended = 1;
2908 
2909 	return 0;
2910 }
2911 
2912 static int musb_runtime_resume(struct device *dev)
2913 {
2914 	struct musb *musb = dev_to_musb(dev);
2915 	unsigned long flags;
2916 	int error;
2917 
2918 	/*
2919 	 * When pm_runtime_get_sync called for the first time in driver
2920 	 * init,  some of the structure is still not initialized which is
2921 	 * used in restore function. But clock needs to be
2922 	 * enabled before any register access, so
2923 	 * pm_runtime_get_sync has to be called.
2924 	 * Also context restore without save does not make
2925 	 * any sense
2926 	 */
2927 	if (!musb->is_initialized)
2928 		return 0;
2929 
2930 	musb_restore_context(musb);
2931 
2932 	spin_lock_irqsave(&musb->lock, flags);
2933 	error = musb_run_resume_work(musb);
2934 	if (error)
2935 		dev_err(musb->controller, "resume work failed with %i\n",
2936 			error);
2937 	musb->is_runtime_suspended = 0;
2938 	spin_unlock_irqrestore(&musb->lock, flags);
2939 
2940 	return 0;
2941 }
2942 
2943 static const struct dev_pm_ops musb_dev_pm_ops = {
2944 	.suspend	= musb_suspend,
2945 	.resume		= musb_resume,
2946 	.runtime_suspend = musb_runtime_suspend,
2947 	.runtime_resume = musb_runtime_resume,
2948 };
2949 
2950 #define MUSB_DEV_PM_OPS (&musb_dev_pm_ops)
2951 #else
2952 #define	MUSB_DEV_PM_OPS	NULL
2953 #endif
2954 
2955 static struct platform_driver musb_driver = {
2956 	.driver = {
2957 		.name		= musb_driver_name,
2958 		.bus		= &platform_bus_type,
2959 		.pm		= MUSB_DEV_PM_OPS,
2960 		.dev_groups	= musb_groups,
2961 	},
2962 	.probe		= musb_probe,
2963 	.remove		= musb_remove,
2964 };
2965 
2966 module_platform_driver(musb_driver);
2967