xref: /linux/drivers/usb/musb/musb_host.c (revision 79997eda0d31bc68203c95ecb978773ee6ce7a1f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * MUSB OTG driver host support
4  *
5  * Copyright 2005 Mentor Graphics Corporation
6  * Copyright (C) 2005-2006 by Texas Instruments
7  * Copyright (C) 2006-2007 Nokia Corporation
8  * Copyright (C) 2008-2009 MontaVista Software, Inc. <source@mvista.com>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/delay.h>
14 #include <linux/sched.h>
15 #include <linux/slab.h>
16 #include <linux/errno.h>
17 #include <linux/list.h>
18 #include <linux/dma-mapping.h>
19 
20 #include "musb_core.h"
21 #include "musb_host.h"
22 #include "musb_trace.h"
23 
24 /* MUSB HOST status 22-mar-2006
25  *
26  * - There's still lots of partial code duplication for fault paths, so
27  *   they aren't handled as consistently as they need to be.
28  *
29  * - PIO mostly behaved when last tested.
30  *     + including ep0, with all usbtest cases 9, 10
31  *     + usbtest 14 (ep0out) doesn't seem to run at all
32  *     + double buffered OUT/TX endpoints saw stalls(!) with certain usbtest
33  *       configurations, but otherwise double buffering passes basic tests.
34  *     + for 2.6.N, for N > ~10, needs API changes for hcd framework.
35  *
36  * - DMA (CPPI) ... partially behaves, not currently recommended
37  *     + about 1/15 the speed of typical EHCI implementations (PCI)
38  *     + RX, all too often reqpkt seems to misbehave after tx
39  *     + TX, no known issues (other than evident silicon issue)
40  *
41  * - DMA (Mentor/OMAP) ...has at least toggle update problems
42  *
43  * - [23-feb-2009] minimal traffic scheduling to avoid bulk RX packet
44  *   starvation ... nothing yet for TX, interrupt, or bulk.
45  *
46  * - Not tested with HNP, but some SRP paths seem to behave.
47  *
48  * NOTE 24-August-2006:
49  *
50  * - Bulk traffic finally uses both sides of hardware ep1, freeing up an
51  *   extra endpoint for periodic use enabling hub + keybd + mouse.  That
52  *   mostly works, except that with "usbnet" it's easy to trigger cases
53  *   with "ping" where RX loses.  (a) ping to davinci, even "ping -f",
54  *   fine; but (b) ping _from_ davinci, even "ping -c 1", ICMP RX loses
55  *   although ARP RX wins.  (That test was done with a full speed link.)
56  */
57 
58 
59 /*
60  * NOTE on endpoint usage:
61  *
62  * CONTROL transfers all go through ep0.  BULK ones go through dedicated IN
63  * and OUT endpoints ... hardware is dedicated for those "async" queue(s).
64  * (Yes, bulk _could_ use more of the endpoints than that, and would even
65  * benefit from it.)
66  *
67  * INTERUPPT and ISOCHRONOUS transfers are scheduled to the other endpoints.
68  * So far that scheduling is both dumb and optimistic:  the endpoint will be
69  * "claimed" until its software queue is no longer refilled.  No multiplexing
70  * of transfers between endpoints, or anything clever.
71  */
72 
73 struct musb *hcd_to_musb(struct usb_hcd *hcd)
74 {
75 	return *(struct musb **) hcd->hcd_priv;
76 }
77 
78 
79 static void musb_ep_program(struct musb *musb, u8 epnum,
80 			struct urb *urb, int is_out,
81 			u8 *buf, u32 offset, u32 len);
82 
83 /*
84  * Clear TX fifo. Needed to avoid BABBLE errors.
85  */
86 static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
87 {
88 	struct musb	*musb = ep->musb;
89 	void __iomem	*epio = ep->regs;
90 	u16		csr;
91 	int		retries = 1000;
92 
93 	csr = musb_readw(epio, MUSB_TXCSR);
94 	while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
95 		csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_TXPKTRDY;
96 		musb_writew(epio, MUSB_TXCSR, csr);
97 		csr = musb_readw(epio, MUSB_TXCSR);
98 
99 		/*
100 		 * FIXME: sometimes the tx fifo flush failed, it has been
101 		 * observed during device disconnect on AM335x.
102 		 *
103 		 * To reproduce the issue, ensure tx urb(s) are queued when
104 		 * unplug the usb device which is connected to AM335x usb
105 		 * host port.
106 		 *
107 		 * I found using a usb-ethernet device and running iperf
108 		 * (client on AM335x) has very high chance to trigger it.
109 		 *
110 		 * Better to turn on musb_dbg() in musb_cleanup_urb() with
111 		 * CPPI enabled to see the issue when aborting the tx channel.
112 		 */
113 		if (dev_WARN_ONCE(musb->controller, retries-- < 1,
114 				"Could not flush host TX%d fifo: csr: %04x\n",
115 				ep->epnum, csr))
116 			return;
117 		mdelay(1);
118 	}
119 }
120 
121 static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep)
122 {
123 	void __iomem	*epio = ep->regs;
124 	u16		csr;
125 	int		retries = 5;
126 
127 	/* scrub any data left in the fifo */
128 	do {
129 		csr = musb_readw(epio, MUSB_TXCSR);
130 		if (!(csr & (MUSB_CSR0_TXPKTRDY | MUSB_CSR0_RXPKTRDY)))
131 			break;
132 		musb_writew(epio, MUSB_TXCSR, MUSB_CSR0_FLUSHFIFO);
133 		csr = musb_readw(epio, MUSB_TXCSR);
134 		udelay(10);
135 	} while (--retries);
136 
137 	WARN(!retries, "Could not flush host TX%d fifo: csr: %04x\n",
138 			ep->epnum, csr);
139 
140 	/* and reset for the next transfer */
141 	musb_writew(epio, MUSB_TXCSR, 0);
142 }
143 
144 /*
145  * Start transmit. Caller is responsible for locking shared resources.
146  * musb must be locked.
147  */
148 static inline void musb_h_tx_start(struct musb_hw_ep *ep)
149 {
150 	u16	txcsr;
151 
152 	/* NOTE: no locks here; caller should lock and select EP */
153 	if (ep->epnum) {
154 		txcsr = musb_readw(ep->regs, MUSB_TXCSR);
155 		txcsr |= MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_H_WZC_BITS;
156 		musb_writew(ep->regs, MUSB_TXCSR, txcsr);
157 	} else {
158 		txcsr = MUSB_CSR0_H_SETUPPKT | MUSB_CSR0_TXPKTRDY;
159 		musb_writew(ep->regs, MUSB_CSR0, txcsr);
160 	}
161 
162 }
163 
164 static inline void musb_h_tx_dma_start(struct musb_hw_ep *ep)
165 {
166 	u16	txcsr;
167 
168 	/* NOTE: no locks here; caller should lock and select EP */
169 	txcsr = musb_readw(ep->regs, MUSB_TXCSR);
170 	txcsr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_H_WZC_BITS;
171 	if (is_cppi_enabled(ep->musb))
172 		txcsr |= MUSB_TXCSR_DMAMODE;
173 	musb_writew(ep->regs, MUSB_TXCSR, txcsr);
174 }
175 
176 static void musb_ep_set_qh(struct musb_hw_ep *ep, int is_in, struct musb_qh *qh)
177 {
178 	if (is_in != 0 || ep->is_shared_fifo)
179 		ep->in_qh  = qh;
180 	if (is_in == 0 || ep->is_shared_fifo)
181 		ep->out_qh = qh;
182 }
183 
184 static struct musb_qh *musb_ep_get_qh(struct musb_hw_ep *ep, int is_in)
185 {
186 	return is_in ? ep->in_qh : ep->out_qh;
187 }
188 
189 /*
190  * Start the URB at the front of an endpoint's queue
191  * end must be claimed from the caller.
192  *
193  * Context: controller locked, irqs blocked
194  */
195 static void
196 musb_start_urb(struct musb *musb, int is_in, struct musb_qh *qh)
197 {
198 	u32			len;
199 	void __iomem		*mbase =  musb->mregs;
200 	struct urb		*urb = next_urb(qh);
201 	void			*buf = urb->transfer_buffer;
202 	u32			offset = 0;
203 	struct musb_hw_ep	*hw_ep = qh->hw_ep;
204 	int			epnum = hw_ep->epnum;
205 
206 	/* initialize software qh state */
207 	qh->offset = 0;
208 	qh->segsize = 0;
209 
210 	/* gather right source of data */
211 	switch (qh->type) {
212 	case USB_ENDPOINT_XFER_CONTROL:
213 		/* control transfers always start with SETUP */
214 		is_in = 0;
215 		musb->ep0_stage = MUSB_EP0_START;
216 		buf = urb->setup_packet;
217 		len = 8;
218 		break;
219 	case USB_ENDPOINT_XFER_ISOC:
220 		qh->iso_idx = 0;
221 		qh->frame = 0;
222 		offset = urb->iso_frame_desc[0].offset;
223 		len = urb->iso_frame_desc[0].length;
224 		break;
225 	default:		/* bulk, interrupt */
226 		/* actual_length may be nonzero on retry paths */
227 		buf = urb->transfer_buffer + urb->actual_length;
228 		len = urb->transfer_buffer_length - urb->actual_length;
229 	}
230 
231 	trace_musb_urb_start(musb, urb);
232 
233 	/* Configure endpoint */
234 	musb_ep_set_qh(hw_ep, is_in, qh);
235 	musb_ep_program(musb, epnum, urb, !is_in, buf, offset, len);
236 
237 	/* transmit may have more work: start it when it is time */
238 	if (is_in)
239 		return;
240 
241 	/* determine if the time is right for a periodic transfer */
242 	switch (qh->type) {
243 	case USB_ENDPOINT_XFER_ISOC:
244 	case USB_ENDPOINT_XFER_INT:
245 		musb_dbg(musb, "check whether there's still time for periodic Tx");
246 		/* FIXME this doesn't implement that scheduling policy ...
247 		 * or handle framecounter wrapping
248 		 */
249 		if (1) {	/* Always assume URB_ISO_ASAP */
250 			/* REVISIT the SOF irq handler shouldn't duplicate
251 			 * this code; and we don't init urb->start_frame...
252 			 */
253 			qh->frame = 0;
254 			goto start;
255 		} else {
256 			qh->frame = urb->start_frame;
257 			/* enable SOF interrupt so we can count down */
258 			musb_dbg(musb, "SOF for %d", epnum);
259 #if 1 /* ifndef	CONFIG_ARCH_DAVINCI */
260 			musb_writeb(mbase, MUSB_INTRUSBE, 0xff);
261 #endif
262 		}
263 		break;
264 	default:
265 start:
266 		musb_dbg(musb, "Start TX%d %s", epnum,
267 			hw_ep->tx_channel ? "dma" : "pio");
268 
269 		if (!hw_ep->tx_channel)
270 			musb_h_tx_start(hw_ep);
271 		else if (is_cppi_enabled(musb) || tusb_dma_omap(musb))
272 			musb_h_tx_dma_start(hw_ep);
273 	}
274 }
275 
276 /* Context: caller owns controller lock, IRQs are blocked */
277 static void musb_giveback(struct musb *musb, struct urb *urb, int status)
278 __releases(musb->lock)
279 __acquires(musb->lock)
280 {
281 	trace_musb_urb_gb(musb, urb);
282 
283 	usb_hcd_unlink_urb_from_ep(musb->hcd, urb);
284 	spin_unlock(&musb->lock);
285 	usb_hcd_giveback_urb(musb->hcd, urb, status);
286 	spin_lock(&musb->lock);
287 }
288 
289 /*
290  * Advance this hardware endpoint's queue, completing the specified URB and
291  * advancing to either the next URB queued to that qh, or else invalidating
292  * that qh and advancing to the next qh scheduled after the current one.
293  *
294  * Context: caller owns controller lock, IRQs are blocked
295  */
296 static void musb_advance_schedule(struct musb *musb, struct urb *urb,
297 				  struct musb_hw_ep *hw_ep, int is_in)
298 {
299 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, is_in);
300 	struct musb_hw_ep	*ep = qh->hw_ep;
301 	int			ready = qh->is_ready;
302 	int			status;
303 	u16			toggle;
304 
305 	status = (urb->status == -EINPROGRESS) ? 0 : urb->status;
306 
307 	/* save toggle eagerly, for paranoia */
308 	switch (qh->type) {
309 	case USB_ENDPOINT_XFER_BULK:
310 	case USB_ENDPOINT_XFER_INT:
311 		toggle = musb->io.get_toggle(qh, !is_in);
312 		usb_settoggle(urb->dev, qh->epnum, !is_in, toggle ? 1 : 0);
313 		break;
314 	case USB_ENDPOINT_XFER_ISOC:
315 		if (status == 0 && urb->error_count)
316 			status = -EXDEV;
317 		break;
318 	}
319 
320 	qh->is_ready = 0;
321 	musb_giveback(musb, urb, status);
322 	qh->is_ready = ready;
323 
324 	/*
325 	 * musb->lock had been unlocked in musb_giveback, so qh may
326 	 * be freed, need to get it again
327 	 */
328 	qh = musb_ep_get_qh(hw_ep, is_in);
329 
330 	/* reclaim resources (and bandwidth) ASAP; deschedule it, and
331 	 * invalidate qh as soon as list_empty(&hep->urb_list)
332 	 */
333 	if (qh && list_empty(&qh->hep->urb_list)) {
334 		struct list_head	*head;
335 		struct dma_controller	*dma = musb->dma_controller;
336 
337 		if (is_in) {
338 			ep->rx_reinit = 1;
339 			if (ep->rx_channel) {
340 				dma->channel_release(ep->rx_channel);
341 				ep->rx_channel = NULL;
342 			}
343 		} else {
344 			ep->tx_reinit = 1;
345 			if (ep->tx_channel) {
346 				dma->channel_release(ep->tx_channel);
347 				ep->tx_channel = NULL;
348 			}
349 		}
350 
351 		/* Clobber old pointers to this qh */
352 		musb_ep_set_qh(ep, is_in, NULL);
353 		qh->hep->hcpriv = NULL;
354 
355 		switch (qh->type) {
356 
357 		case USB_ENDPOINT_XFER_CONTROL:
358 		case USB_ENDPOINT_XFER_BULK:
359 			/* fifo policy for these lists, except that NAKing
360 			 * should rotate a qh to the end (for fairness).
361 			 */
362 			if (qh->mux == 1) {
363 				head = qh->ring.prev;
364 				list_del(&qh->ring);
365 				kfree(qh);
366 				qh = first_qh(head);
367 				break;
368 			}
369 			fallthrough;
370 
371 		case USB_ENDPOINT_XFER_ISOC:
372 		case USB_ENDPOINT_XFER_INT:
373 			/* this is where periodic bandwidth should be
374 			 * de-allocated if it's tracked and allocated;
375 			 * and where we'd update the schedule tree...
376 			 */
377 			kfree(qh);
378 			qh = NULL;
379 			break;
380 		}
381 	}
382 
383 	if (qh != NULL && qh->is_ready) {
384 		musb_dbg(musb, "... next ep%d %cX urb %p",
385 		    hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh));
386 		musb_start_urb(musb, is_in, qh);
387 	}
388 }
389 
390 static u16 musb_h_flush_rxfifo(struct musb_hw_ep *hw_ep, u16 csr)
391 {
392 	/* we don't want fifo to fill itself again;
393 	 * ignore dma (various models),
394 	 * leave toggle alone (may not have been saved yet)
395 	 */
396 	csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_RXPKTRDY;
397 	csr &= ~(MUSB_RXCSR_H_REQPKT
398 		| MUSB_RXCSR_H_AUTOREQ
399 		| MUSB_RXCSR_AUTOCLEAR);
400 
401 	/* write 2x to allow double buffering */
402 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
403 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
404 
405 	/* flush writebuffer */
406 	return musb_readw(hw_ep->regs, MUSB_RXCSR);
407 }
408 
409 /*
410  * PIO RX for a packet (or part of it).
411  */
412 static bool
413 musb_host_packet_rx(struct musb *musb, struct urb *urb, u8 epnum, u8 iso_err)
414 {
415 	u16			rx_count;
416 	u8			*buf;
417 	u16			csr;
418 	bool			done = false;
419 	u32			length;
420 	int			do_flush = 0;
421 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
422 	void __iomem		*epio = hw_ep->regs;
423 	struct musb_qh		*qh = hw_ep->in_qh;
424 	int			pipe = urb->pipe;
425 	void			*buffer = urb->transfer_buffer;
426 
427 	/* musb_ep_select(mbase, epnum); */
428 	rx_count = musb_readw(epio, MUSB_RXCOUNT);
429 	musb_dbg(musb, "RX%d count %d, buffer %p len %d/%d", epnum, rx_count,
430 			urb->transfer_buffer, qh->offset,
431 			urb->transfer_buffer_length);
432 
433 	/* unload FIFO */
434 	if (usb_pipeisoc(pipe)) {
435 		int					status = 0;
436 		struct usb_iso_packet_descriptor	*d;
437 
438 		if (iso_err) {
439 			status = -EILSEQ;
440 			urb->error_count++;
441 		}
442 
443 		d = urb->iso_frame_desc + qh->iso_idx;
444 		buf = buffer + d->offset;
445 		length = d->length;
446 		if (rx_count > length) {
447 			if (status == 0) {
448 				status = -EOVERFLOW;
449 				urb->error_count++;
450 			}
451 			musb_dbg(musb, "OVERFLOW %d into %d", rx_count, length);
452 			do_flush = 1;
453 		} else
454 			length = rx_count;
455 		urb->actual_length += length;
456 		d->actual_length = length;
457 
458 		d->status = status;
459 
460 		/* see if we are done */
461 		done = (++qh->iso_idx >= urb->number_of_packets);
462 	} else {
463 		/* non-isoch */
464 		buf = buffer + qh->offset;
465 		length = urb->transfer_buffer_length - qh->offset;
466 		if (rx_count > length) {
467 			if (urb->status == -EINPROGRESS)
468 				urb->status = -EOVERFLOW;
469 			musb_dbg(musb, "OVERFLOW %d into %d", rx_count, length);
470 			do_flush = 1;
471 		} else
472 			length = rx_count;
473 		urb->actual_length += length;
474 		qh->offset += length;
475 
476 		/* see if we are done */
477 		done = (urb->actual_length == urb->transfer_buffer_length)
478 			|| (rx_count < qh->maxpacket)
479 			|| (urb->status != -EINPROGRESS);
480 		if (done
481 				&& (urb->status == -EINPROGRESS)
482 				&& (urb->transfer_flags & URB_SHORT_NOT_OK)
483 				&& (urb->actual_length
484 					< urb->transfer_buffer_length))
485 			urb->status = -EREMOTEIO;
486 	}
487 
488 	musb_read_fifo(hw_ep, length, buf);
489 
490 	csr = musb_readw(epio, MUSB_RXCSR);
491 	csr |= MUSB_RXCSR_H_WZC_BITS;
492 	if (unlikely(do_flush))
493 		musb_h_flush_rxfifo(hw_ep, csr);
494 	else {
495 		/* REVISIT this assumes AUTOCLEAR is never set */
496 		csr &= ~(MUSB_RXCSR_RXPKTRDY | MUSB_RXCSR_H_REQPKT);
497 		if (!done)
498 			csr |= MUSB_RXCSR_H_REQPKT;
499 		musb_writew(epio, MUSB_RXCSR, csr);
500 	}
501 
502 	return done;
503 }
504 
505 /* we don't always need to reinit a given side of an endpoint...
506  * when we do, use tx/rx reinit routine and then construct a new CSR
507  * to address data toggle, NYET, and DMA or PIO.
508  *
509  * it's possible that driver bugs (especially for DMA) or aborting a
510  * transfer might have left the endpoint busier than it should be.
511  * the busy/not-empty tests are basically paranoia.
512  */
513 static void
514 musb_rx_reinit(struct musb *musb, struct musb_qh *qh, u8 epnum)
515 {
516 	struct musb_hw_ep *ep = musb->endpoints + epnum;
517 	u16	csr;
518 
519 	/* NOTE:  we know the "rx" fifo reinit never triggers for ep0.
520 	 * That always uses tx_reinit since ep0 repurposes TX register
521 	 * offsets; the initial SETUP packet is also a kind of OUT.
522 	 */
523 
524 	/* if programmed for Tx, put it in RX mode */
525 	if (ep->is_shared_fifo) {
526 		csr = musb_readw(ep->regs, MUSB_TXCSR);
527 		if (csr & MUSB_TXCSR_MODE) {
528 			musb_h_tx_flush_fifo(ep);
529 			csr = musb_readw(ep->regs, MUSB_TXCSR);
530 			musb_writew(ep->regs, MUSB_TXCSR,
531 				    csr | MUSB_TXCSR_FRCDATATOG);
532 		}
533 
534 		/*
535 		 * Clear the MODE bit (and everything else) to enable Rx.
536 		 * NOTE: we mustn't clear the DMAMODE bit before DMAENAB.
537 		 */
538 		if (csr & MUSB_TXCSR_DMAMODE)
539 			musb_writew(ep->regs, MUSB_TXCSR, MUSB_TXCSR_DMAMODE);
540 		musb_writew(ep->regs, MUSB_TXCSR, 0);
541 
542 	/* scrub all previous state, clearing toggle */
543 	}
544 	csr = musb_readw(ep->regs, MUSB_RXCSR);
545 	if (csr & MUSB_RXCSR_RXPKTRDY)
546 		WARNING("rx%d, packet/%d ready?\n", ep->epnum,
547 			musb_readw(ep->regs, MUSB_RXCOUNT));
548 
549 	musb_h_flush_rxfifo(ep, MUSB_RXCSR_CLRDATATOG);
550 
551 	/* target addr and (for multipoint) hub addr/port */
552 	if (musb->is_multipoint) {
553 		musb_write_rxfunaddr(musb, epnum, qh->addr_reg);
554 		musb_write_rxhubaddr(musb, epnum, qh->h_addr_reg);
555 		musb_write_rxhubport(musb, epnum, qh->h_port_reg);
556 	} else
557 		musb_writeb(musb->mregs, MUSB_FADDR, qh->addr_reg);
558 
559 	/* protocol/endpoint, interval/NAKlimit, i/o size */
560 	musb_writeb(ep->regs, MUSB_RXTYPE, qh->type_reg);
561 	musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);
562 	/* NOTE: bulk combining rewrites high bits of maxpacket */
563 	/* Set RXMAXP with the FIFO size of the endpoint
564 	 * to disable double buffer mode.
565 	 */
566 	musb_writew(ep->regs, MUSB_RXMAXP,
567 			qh->maxpacket | ((qh->hb_mult - 1) << 11));
568 
569 	ep->rx_reinit = 0;
570 }
571 
572 static void musb_tx_dma_set_mode_mentor(struct musb_hw_ep *hw_ep,
573 					struct musb_qh *qh,
574 					u32 *length, u8 *mode)
575 {
576 	struct dma_channel	*channel = hw_ep->tx_channel;
577 	void __iomem		*epio = hw_ep->regs;
578 	u16			pkt_size = qh->maxpacket;
579 	u16			csr;
580 
581 	if (*length > channel->max_len)
582 		*length = channel->max_len;
583 
584 	csr = musb_readw(epio, MUSB_TXCSR);
585 	if (*length > pkt_size) {
586 		*mode = 1;
587 		csr |= MUSB_TXCSR_DMAMODE | MUSB_TXCSR_DMAENAB;
588 		/* autoset shouldn't be set in high bandwidth */
589 		/*
590 		 * Enable Autoset according to table
591 		 * below
592 		 * bulk_split hb_mult	Autoset_Enable
593 		 *	0	1	Yes(Normal)
594 		 *	0	>1	No(High BW ISO)
595 		 *	1	1	Yes(HS bulk)
596 		 *	1	>1	Yes(FS bulk)
597 		 */
598 		if (qh->hb_mult == 1 || (qh->hb_mult > 1 &&
599 					can_bulk_split(hw_ep->musb, qh->type)))
600 			csr |= MUSB_TXCSR_AUTOSET;
601 	} else {
602 		*mode = 0;
603 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAMODE);
604 		csr |= MUSB_TXCSR_DMAENAB; /* against programmer's guide */
605 	}
606 	channel->desired_mode = *mode;
607 	musb_writew(epio, MUSB_TXCSR, csr);
608 }
609 
610 static void musb_tx_dma_set_mode_cppi_tusb(struct musb_hw_ep *hw_ep,
611 					   struct urb *urb,
612 					   u8 *mode)
613 {
614 	struct dma_channel *channel = hw_ep->tx_channel;
615 
616 	channel->actual_len = 0;
617 
618 	/*
619 	 * TX uses "RNDIS" mode automatically but needs help
620 	 * to identify the zero-length-final-packet case.
621 	 */
622 	*mode = (urb->transfer_flags & URB_ZERO_PACKET) ? 1 : 0;
623 }
624 
625 static bool musb_tx_dma_program(struct dma_controller *dma,
626 		struct musb_hw_ep *hw_ep, struct musb_qh *qh,
627 		struct urb *urb, u32 offset, u32 length)
628 {
629 	struct dma_channel	*channel = hw_ep->tx_channel;
630 	u16			pkt_size = qh->maxpacket;
631 	u8			mode;
632 
633 	if (musb_dma_inventra(hw_ep->musb) || musb_dma_ux500(hw_ep->musb))
634 		musb_tx_dma_set_mode_mentor(hw_ep, qh,
635 					    &length, &mode);
636 	else if (is_cppi_enabled(hw_ep->musb) || tusb_dma_omap(hw_ep->musb))
637 		musb_tx_dma_set_mode_cppi_tusb(hw_ep, urb, &mode);
638 	else
639 		return false;
640 
641 	qh->segsize = length;
642 
643 	/*
644 	 * Ensure the data reaches to main memory before starting
645 	 * DMA transfer
646 	 */
647 	wmb();
648 
649 	if (!dma->channel_program(channel, pkt_size, mode,
650 			urb->transfer_dma + offset, length)) {
651 		void __iomem *epio = hw_ep->regs;
652 		u16 csr;
653 
654 		dma->channel_release(channel);
655 		hw_ep->tx_channel = NULL;
656 
657 		csr = musb_readw(epio, MUSB_TXCSR);
658 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
659 		musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_H_WZC_BITS);
660 		return false;
661 	}
662 	return true;
663 }
664 
665 /*
666  * Program an HDRC endpoint as per the given URB
667  * Context: irqs blocked, controller lock held
668  */
669 static void musb_ep_program(struct musb *musb, u8 epnum,
670 			struct urb *urb, int is_out,
671 			u8 *buf, u32 offset, u32 len)
672 {
673 	struct dma_controller	*dma_controller;
674 	struct dma_channel	*dma_channel;
675 	u8			dma_ok;
676 	void __iomem		*mbase = musb->mregs;
677 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
678 	void __iomem		*epio = hw_ep->regs;
679 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, !is_out);
680 	u16			packet_sz = qh->maxpacket;
681 	u8			use_dma = 1;
682 	u16			csr;
683 
684 	musb_dbg(musb, "%s hw%d urb %p spd%d dev%d ep%d%s "
685 				"h_addr%02x h_port%02x bytes %d",
686 			is_out ? "-->" : "<--",
687 			epnum, urb, urb->dev->speed,
688 			qh->addr_reg, qh->epnum, is_out ? "out" : "in",
689 			qh->h_addr_reg, qh->h_port_reg,
690 			len);
691 
692 	musb_ep_select(mbase, epnum);
693 
694 	if (is_out && !len) {
695 		use_dma = 0;
696 		csr = musb_readw(epio, MUSB_TXCSR);
697 		csr &= ~MUSB_TXCSR_DMAENAB;
698 		musb_writew(epio, MUSB_TXCSR, csr);
699 		hw_ep->tx_channel = NULL;
700 	}
701 
702 	/* candidate for DMA? */
703 	dma_controller = musb->dma_controller;
704 	if (use_dma && is_dma_capable() && epnum && dma_controller) {
705 		dma_channel = is_out ? hw_ep->tx_channel : hw_ep->rx_channel;
706 		if (!dma_channel) {
707 			dma_channel = dma_controller->channel_alloc(
708 					dma_controller, hw_ep, is_out);
709 			if (is_out)
710 				hw_ep->tx_channel = dma_channel;
711 			else
712 				hw_ep->rx_channel = dma_channel;
713 		}
714 	} else
715 		dma_channel = NULL;
716 
717 	/* make sure we clear DMAEnab, autoSet bits from previous run */
718 
719 	/* OUT/transmit/EP0 or IN/receive? */
720 	if (is_out) {
721 		u16	csr;
722 		u16	int_txe;
723 		u16	load_count;
724 
725 		csr = musb_readw(epio, MUSB_TXCSR);
726 
727 		/* disable interrupt in case we flush */
728 		int_txe = musb->intrtxe;
729 		musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
730 
731 		/* general endpoint setup */
732 		if (epnum) {
733 			/* flush all old state, set default */
734 			/*
735 			 * We could be flushing valid
736 			 * packets in double buffering
737 			 * case
738 			 */
739 			if (!hw_ep->tx_double_buffered)
740 				musb_h_tx_flush_fifo(hw_ep);
741 
742 			/*
743 			 * We must not clear the DMAMODE bit before or in
744 			 * the same cycle with the DMAENAB bit, so we clear
745 			 * the latter first...
746 			 */
747 			csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
748 					| MUSB_TXCSR_AUTOSET
749 					| MUSB_TXCSR_DMAENAB
750 					| MUSB_TXCSR_FRCDATATOG
751 					| MUSB_TXCSR_H_RXSTALL
752 					| MUSB_TXCSR_H_ERROR
753 					| MUSB_TXCSR_TXPKTRDY
754 					);
755 			csr |= MUSB_TXCSR_MODE;
756 
757 			if (!hw_ep->tx_double_buffered)
758 				csr |= musb->io.set_toggle(qh, is_out, urb);
759 
760 			musb_writew(epio, MUSB_TXCSR, csr);
761 			/* REVISIT may need to clear FLUSHFIFO ... */
762 			csr &= ~MUSB_TXCSR_DMAMODE;
763 			musb_writew(epio, MUSB_TXCSR, csr);
764 			csr = musb_readw(epio, MUSB_TXCSR);
765 		} else {
766 			/* endpoint 0: just flush */
767 			musb_h_ep0_flush_fifo(hw_ep);
768 		}
769 
770 		/* target addr and (for multipoint) hub addr/port */
771 		if (musb->is_multipoint) {
772 			musb_write_txfunaddr(musb, epnum, qh->addr_reg);
773 			musb_write_txhubaddr(musb, epnum, qh->h_addr_reg);
774 			musb_write_txhubport(musb, epnum, qh->h_port_reg);
775 /* FIXME if !epnum, do the same for RX ... */
776 		} else
777 			musb_writeb(mbase, MUSB_FADDR, qh->addr_reg);
778 
779 		/* protocol/endpoint/interval/NAKlimit */
780 		if (epnum) {
781 			musb_writeb(epio, MUSB_TXTYPE, qh->type_reg);
782 			if (can_bulk_split(musb, qh->type)) {
783 				qh->hb_mult = hw_ep->max_packet_sz_tx
784 						/ packet_sz;
785 				musb_writew(epio, MUSB_TXMAXP, packet_sz
786 					| ((qh->hb_mult) - 1) << 11);
787 			} else {
788 				musb_writew(epio, MUSB_TXMAXP,
789 						qh->maxpacket |
790 						((qh->hb_mult - 1) << 11));
791 			}
792 			musb_writeb(epio, MUSB_TXINTERVAL, qh->intv_reg);
793 		} else {
794 			musb_writeb(epio, MUSB_NAKLIMIT0, qh->intv_reg);
795 			if (musb->is_multipoint)
796 				musb_writeb(epio, MUSB_TYPE0,
797 						qh->type_reg);
798 		}
799 
800 		if (can_bulk_split(musb, qh->type))
801 			load_count = min((u32) hw_ep->max_packet_sz_tx,
802 						len);
803 		else
804 			load_count = min((u32) packet_sz, len);
805 
806 		if (dma_channel && musb_tx_dma_program(dma_controller,
807 					hw_ep, qh, urb, offset, len))
808 			load_count = 0;
809 
810 		if (load_count) {
811 			/* PIO to load FIFO */
812 			qh->segsize = load_count;
813 			if (!buf) {
814 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
815 						SG_MITER_ATOMIC
816 						| SG_MITER_FROM_SG);
817 				if (!sg_miter_next(&qh->sg_miter)) {
818 					dev_err(musb->controller,
819 							"error: sg"
820 							"list empty\n");
821 					sg_miter_stop(&qh->sg_miter);
822 					goto finish;
823 				}
824 				buf = qh->sg_miter.addr + urb->sg->offset +
825 					urb->actual_length;
826 				load_count = min_t(u32, load_count,
827 						qh->sg_miter.length);
828 				musb_write_fifo(hw_ep, load_count, buf);
829 				qh->sg_miter.consumed = load_count;
830 				sg_miter_stop(&qh->sg_miter);
831 			} else
832 				musb_write_fifo(hw_ep, load_count, buf);
833 		}
834 finish:
835 		/* re-enable interrupt */
836 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
837 
838 	/* IN/receive */
839 	} else {
840 		u16 csr = 0;
841 
842 		if (hw_ep->rx_reinit) {
843 			musb_rx_reinit(musb, qh, epnum);
844 			csr |= musb->io.set_toggle(qh, is_out, urb);
845 
846 			if (qh->type == USB_ENDPOINT_XFER_INT)
847 				csr |= MUSB_RXCSR_DISNYET;
848 
849 		} else {
850 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
851 
852 			if (csr & (MUSB_RXCSR_RXPKTRDY
853 					| MUSB_RXCSR_DMAENAB
854 					| MUSB_RXCSR_H_REQPKT))
855 				ERR("broken !rx_reinit, ep%d csr %04x\n",
856 						hw_ep->epnum, csr);
857 
858 			/* scrub any stale state, leaving toggle alone */
859 			csr &= MUSB_RXCSR_DISNYET;
860 		}
861 
862 		/* kick things off */
863 
864 		if ((is_cppi_enabled(musb) || tusb_dma_omap(musb)) && dma_channel) {
865 			/* Candidate for DMA */
866 			dma_channel->actual_len = 0L;
867 			qh->segsize = len;
868 
869 			/* AUTOREQ is in a DMA register */
870 			musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
871 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
872 
873 			/*
874 			 * Unless caller treats short RX transfers as
875 			 * errors, we dare not queue multiple transfers.
876 			 */
877 			dma_ok = dma_controller->channel_program(dma_channel,
878 					packet_sz, !(urb->transfer_flags &
879 						     URB_SHORT_NOT_OK),
880 					urb->transfer_dma + offset,
881 					qh->segsize);
882 			if (!dma_ok) {
883 				dma_controller->channel_release(dma_channel);
884 				hw_ep->rx_channel = dma_channel = NULL;
885 			} else
886 				csr |= MUSB_RXCSR_DMAENAB;
887 		}
888 
889 		csr |= MUSB_RXCSR_H_REQPKT;
890 		musb_dbg(musb, "RXCSR%d := %04x", epnum, csr);
891 		musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
892 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
893 	}
894 }
895 
896 /* Schedule next QH from musb->in_bulk/out_bulk and move the current qh to
897  * the end; avoids starvation for other endpoints.
898  */
899 static void musb_bulk_nak_timeout(struct musb *musb, struct musb_hw_ep *ep,
900 	int is_in)
901 {
902 	struct dma_channel	*dma;
903 	struct urb		*urb;
904 	void __iomem		*mbase = musb->mregs;
905 	void __iomem		*epio = ep->regs;
906 	struct musb_qh		*cur_qh, *next_qh;
907 	u16			rx_csr, tx_csr;
908 	u16			toggle;
909 
910 	musb_ep_select(mbase, ep->epnum);
911 	if (is_in) {
912 		dma = is_dma_capable() ? ep->rx_channel : NULL;
913 
914 		/*
915 		 * Need to stop the transaction by clearing REQPKT first
916 		 * then the NAK Timeout bit ref MUSBMHDRC USB 2.0 HIGH-SPEED
917 		 * DUAL-ROLE CONTROLLER Programmer's Guide, section 9.2.2
918 		 */
919 		rx_csr = musb_readw(epio, MUSB_RXCSR);
920 		rx_csr |= MUSB_RXCSR_H_WZC_BITS;
921 		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
922 		musb_writew(epio, MUSB_RXCSR, rx_csr);
923 		rx_csr &= ~MUSB_RXCSR_DATAERROR;
924 		musb_writew(epio, MUSB_RXCSR, rx_csr);
925 
926 		cur_qh = first_qh(&musb->in_bulk);
927 	} else {
928 		dma = is_dma_capable() ? ep->tx_channel : NULL;
929 
930 		/* clear nak timeout bit */
931 		tx_csr = musb_readw(epio, MUSB_TXCSR);
932 		tx_csr |= MUSB_TXCSR_H_WZC_BITS;
933 		tx_csr &= ~MUSB_TXCSR_H_NAKTIMEOUT;
934 		musb_writew(epio, MUSB_TXCSR, tx_csr);
935 
936 		cur_qh = first_qh(&musb->out_bulk);
937 	}
938 	if (cur_qh) {
939 		urb = next_urb(cur_qh);
940 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
941 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
942 			musb->dma_controller->channel_abort(dma);
943 			urb->actual_length += dma->actual_len;
944 			dma->actual_len = 0L;
945 		}
946 		toggle = musb->io.get_toggle(cur_qh, !is_in);
947 		usb_settoggle(urb->dev, cur_qh->epnum, !is_in, toggle ? 1 : 0);
948 
949 		if (is_in) {
950 			/* move cur_qh to end of queue */
951 			list_move_tail(&cur_qh->ring, &musb->in_bulk);
952 
953 			/* get the next qh from musb->in_bulk */
954 			next_qh = first_qh(&musb->in_bulk);
955 
956 			/* set rx_reinit and schedule the next qh */
957 			ep->rx_reinit = 1;
958 		} else {
959 			/* move cur_qh to end of queue */
960 			list_move_tail(&cur_qh->ring, &musb->out_bulk);
961 
962 			/* get the next qh from musb->out_bulk */
963 			next_qh = first_qh(&musb->out_bulk);
964 
965 			/* set tx_reinit and schedule the next qh */
966 			ep->tx_reinit = 1;
967 		}
968 
969 		if (next_qh)
970 			musb_start_urb(musb, is_in, next_qh);
971 	}
972 }
973 
974 /*
975  * Service the default endpoint (ep0) as host.
976  * Return true until it's time to start the status stage.
977  */
978 static bool musb_h_ep0_continue(struct musb *musb, u16 len, struct urb *urb)
979 {
980 	bool			 more = false;
981 	u8			*fifo_dest = NULL;
982 	u16			fifo_count = 0;
983 	struct musb_hw_ep	*hw_ep = musb->control_ep;
984 	struct musb_qh		*qh = hw_ep->in_qh;
985 	struct usb_ctrlrequest	*request;
986 
987 	switch (musb->ep0_stage) {
988 	case MUSB_EP0_IN:
989 		fifo_dest = urb->transfer_buffer + urb->actual_length;
990 		fifo_count = min_t(size_t, len, urb->transfer_buffer_length -
991 				   urb->actual_length);
992 		if (fifo_count < len)
993 			urb->status = -EOVERFLOW;
994 
995 		musb_read_fifo(hw_ep, fifo_count, fifo_dest);
996 
997 		urb->actual_length += fifo_count;
998 		if (len < qh->maxpacket) {
999 			/* always terminate on short read; it's
1000 			 * rarely reported as an error.
1001 			 */
1002 		} else if (urb->actual_length <
1003 				urb->transfer_buffer_length)
1004 			more = true;
1005 		break;
1006 	case MUSB_EP0_START:
1007 		request = (struct usb_ctrlrequest *) urb->setup_packet;
1008 
1009 		if (!request->wLength) {
1010 			musb_dbg(musb, "start no-DATA");
1011 			break;
1012 		} else if (request->bRequestType & USB_DIR_IN) {
1013 			musb_dbg(musb, "start IN-DATA");
1014 			musb->ep0_stage = MUSB_EP0_IN;
1015 			more = true;
1016 			break;
1017 		} else {
1018 			musb_dbg(musb, "start OUT-DATA");
1019 			musb->ep0_stage = MUSB_EP0_OUT;
1020 			more = true;
1021 		}
1022 		fallthrough;
1023 	case MUSB_EP0_OUT:
1024 		fifo_count = min_t(size_t, qh->maxpacket,
1025 				   urb->transfer_buffer_length -
1026 				   urb->actual_length);
1027 		if (fifo_count) {
1028 			fifo_dest = (u8 *) (urb->transfer_buffer
1029 					+ urb->actual_length);
1030 			musb_dbg(musb, "Sending %d byte%s to ep0 fifo %p",
1031 					fifo_count,
1032 					(fifo_count == 1) ? "" : "s",
1033 					fifo_dest);
1034 			musb_write_fifo(hw_ep, fifo_count, fifo_dest);
1035 
1036 			urb->actual_length += fifo_count;
1037 			more = true;
1038 		}
1039 		break;
1040 	default:
1041 		ERR("bogus ep0 stage %d\n", musb->ep0_stage);
1042 		break;
1043 	}
1044 
1045 	return more;
1046 }
1047 
1048 /*
1049  * Handle default endpoint interrupt as host. Only called in IRQ time
1050  * from musb_interrupt().
1051  *
1052  * called with controller irqlocked
1053  */
1054 irqreturn_t musb_h_ep0_irq(struct musb *musb)
1055 {
1056 	struct urb		*urb;
1057 	u16			csr, len;
1058 	int			status = 0;
1059 	void __iomem		*mbase = musb->mregs;
1060 	struct musb_hw_ep	*hw_ep = musb->control_ep;
1061 	void __iomem		*epio = hw_ep->regs;
1062 	struct musb_qh		*qh = hw_ep->in_qh;
1063 	bool			complete = false;
1064 	irqreturn_t		retval = IRQ_NONE;
1065 
1066 	/* ep0 only has one queue, "in" */
1067 	urb = next_urb(qh);
1068 
1069 	musb_ep_select(mbase, 0);
1070 	csr = musb_readw(epio, MUSB_CSR0);
1071 	len = (csr & MUSB_CSR0_RXPKTRDY)
1072 			? musb_readb(epio, MUSB_COUNT0)
1073 			: 0;
1074 
1075 	musb_dbg(musb, "<== csr0 %04x, qh %p, count %d, urb %p, stage %d",
1076 		csr, qh, len, urb, musb->ep0_stage);
1077 
1078 	/* if we just did status stage, we are done */
1079 	if (MUSB_EP0_STATUS == musb->ep0_stage) {
1080 		retval = IRQ_HANDLED;
1081 		complete = true;
1082 	}
1083 
1084 	/* prepare status */
1085 	if (csr & MUSB_CSR0_H_RXSTALL) {
1086 		musb_dbg(musb, "STALLING ENDPOINT");
1087 		status = -EPIPE;
1088 
1089 	} else if (csr & MUSB_CSR0_H_ERROR) {
1090 		musb_dbg(musb, "no response, csr0 %04x", csr);
1091 		status = -EPROTO;
1092 
1093 	} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
1094 		musb_dbg(musb, "control NAK timeout");
1095 
1096 		/* NOTE:  this code path would be a good place to PAUSE a
1097 		 * control transfer, if another one is queued, so that
1098 		 * ep0 is more likely to stay busy.  That's already done
1099 		 * for bulk RX transfers.
1100 		 *
1101 		 * if (qh->ring.next != &musb->control), then
1102 		 * we have a candidate... NAKing is *NOT* an error
1103 		 */
1104 		musb_writew(epio, MUSB_CSR0, 0);
1105 		retval = IRQ_HANDLED;
1106 	}
1107 
1108 	if (status) {
1109 		musb_dbg(musb, "aborting");
1110 		retval = IRQ_HANDLED;
1111 		if (urb)
1112 			urb->status = status;
1113 		complete = true;
1114 
1115 		/* use the proper sequence to abort the transfer */
1116 		if (csr & MUSB_CSR0_H_REQPKT) {
1117 			csr &= ~MUSB_CSR0_H_REQPKT;
1118 			musb_writew(epio, MUSB_CSR0, csr);
1119 			csr &= ~MUSB_CSR0_H_NAKTIMEOUT;
1120 			musb_writew(epio, MUSB_CSR0, csr);
1121 		} else {
1122 			musb_h_ep0_flush_fifo(hw_ep);
1123 		}
1124 
1125 		musb_writeb(epio, MUSB_NAKLIMIT0, 0);
1126 
1127 		/* clear it */
1128 		musb_writew(epio, MUSB_CSR0, 0);
1129 	}
1130 
1131 	if (unlikely(!urb)) {
1132 		/* stop endpoint since we have no place for its data, this
1133 		 * SHOULD NEVER HAPPEN! */
1134 		ERR("no URB for end 0\n");
1135 
1136 		musb_h_ep0_flush_fifo(hw_ep);
1137 		goto done;
1138 	}
1139 
1140 	if (!complete) {
1141 		/* call common logic and prepare response */
1142 		if (musb_h_ep0_continue(musb, len, urb)) {
1143 			/* more packets required */
1144 			csr = (MUSB_EP0_IN == musb->ep0_stage)
1145 				?  MUSB_CSR0_H_REQPKT : MUSB_CSR0_TXPKTRDY;
1146 		} else {
1147 			/* data transfer complete; perform status phase */
1148 			if (usb_pipeout(urb->pipe)
1149 					|| !urb->transfer_buffer_length)
1150 				csr = MUSB_CSR0_H_STATUSPKT
1151 					| MUSB_CSR0_H_REQPKT;
1152 			else
1153 				csr = MUSB_CSR0_H_STATUSPKT
1154 					| MUSB_CSR0_TXPKTRDY;
1155 
1156 			/* disable ping token in status phase */
1157 			csr |= MUSB_CSR0_H_DIS_PING;
1158 
1159 			/* flag status stage */
1160 			musb->ep0_stage = MUSB_EP0_STATUS;
1161 
1162 			musb_dbg(musb, "ep0 STATUS, csr %04x", csr);
1163 
1164 		}
1165 		musb_writew(epio, MUSB_CSR0, csr);
1166 		retval = IRQ_HANDLED;
1167 	} else
1168 		musb->ep0_stage = MUSB_EP0_IDLE;
1169 
1170 	/* call completion handler if done */
1171 	if (complete)
1172 		musb_advance_schedule(musb, urb, hw_ep, 1);
1173 done:
1174 	return retval;
1175 }
1176 
1177 
1178 #ifdef CONFIG_USB_INVENTRA_DMA
1179 
1180 /* Host side TX (OUT) using Mentor DMA works as follows:
1181 	submit_urb ->
1182 		- if queue was empty, Program Endpoint
1183 		- ... which starts DMA to fifo in mode 1 or 0
1184 
1185 	DMA Isr (transfer complete) -> TxAvail()
1186 		- Stop DMA (~DmaEnab)	(<--- Alert ... currently happens
1187 					only in musb_cleanup_urb)
1188 		- TxPktRdy has to be set in mode 0 or for
1189 			short packets in mode 1.
1190 */
1191 
1192 #endif
1193 
1194 /* Service a Tx-Available or dma completion irq for the endpoint */
1195 void musb_host_tx(struct musb *musb, u8 epnum)
1196 {
1197 	int			pipe;
1198 	bool			done = false;
1199 	u16			tx_csr;
1200 	size_t			length = 0;
1201 	size_t			offset = 0;
1202 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1203 	void __iomem		*epio = hw_ep->regs;
1204 	struct musb_qh		*qh = hw_ep->out_qh;
1205 	struct urb		*urb = next_urb(qh);
1206 	u32			status = 0;
1207 	void __iomem		*mbase = musb->mregs;
1208 	struct dma_channel	*dma;
1209 	bool			transfer_pending = false;
1210 
1211 	musb_ep_select(mbase, epnum);
1212 	tx_csr = musb_readw(epio, MUSB_TXCSR);
1213 
1214 	/* with CPPI, DMA sometimes triggers "extra" irqs */
1215 	if (!urb) {
1216 		musb_dbg(musb, "extra TX%d ready, csr %04x", epnum, tx_csr);
1217 		return;
1218 	}
1219 
1220 	pipe = urb->pipe;
1221 	dma = is_dma_capable() ? hw_ep->tx_channel : NULL;
1222 	trace_musb_urb_tx(musb, urb);
1223 	musb_dbg(musb, "OUT/TX%d end, csr %04x%s", epnum, tx_csr,
1224 			dma ? ", dma" : "");
1225 
1226 	/* check for errors */
1227 	if (tx_csr & MUSB_TXCSR_H_RXSTALL) {
1228 		/* dma was disabled, fifo flushed */
1229 		musb_dbg(musb, "TX end %d stall", epnum);
1230 
1231 		/* stall; record URB status */
1232 		status = -EPIPE;
1233 
1234 	} else if (tx_csr & MUSB_TXCSR_H_ERROR) {
1235 		/* (NON-ISO) dma was disabled, fifo flushed */
1236 		musb_dbg(musb, "TX 3strikes on ep=%d", epnum);
1237 
1238 		status = -ETIMEDOUT;
1239 
1240 	} else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) {
1241 		if (USB_ENDPOINT_XFER_BULK == qh->type && qh->mux == 1
1242 				&& !list_is_singular(&musb->out_bulk)) {
1243 			musb_dbg(musb, "NAK timeout on TX%d ep", epnum);
1244 			musb_bulk_nak_timeout(musb, hw_ep, 0);
1245 		} else {
1246 			musb_dbg(musb, "TX ep%d device not responding", epnum);
1247 			/* NOTE:  this code path would be a good place to PAUSE a
1248 			 * transfer, if there's some other (nonperiodic) tx urb
1249 			 * that could use this fifo.  (dma complicates it...)
1250 			 * That's already done for bulk RX transfers.
1251 			 *
1252 			 * if (bulk && qh->ring.next != &musb->out_bulk), then
1253 			 * we have a candidate... NAKing is *NOT* an error
1254 			 */
1255 			musb_ep_select(mbase, epnum);
1256 			musb_writew(epio, MUSB_TXCSR,
1257 					MUSB_TXCSR_H_WZC_BITS
1258 					| MUSB_TXCSR_TXPKTRDY);
1259 		}
1260 		return;
1261 	}
1262 
1263 done:
1264 	if (status) {
1265 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1266 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1267 			musb->dma_controller->channel_abort(dma);
1268 		}
1269 
1270 		/* do the proper sequence to abort the transfer in the
1271 		 * usb core; the dma engine should already be stopped.
1272 		 */
1273 		musb_h_tx_flush_fifo(hw_ep);
1274 		tx_csr &= ~(MUSB_TXCSR_AUTOSET
1275 				| MUSB_TXCSR_DMAENAB
1276 				| MUSB_TXCSR_H_ERROR
1277 				| MUSB_TXCSR_H_RXSTALL
1278 				| MUSB_TXCSR_H_NAKTIMEOUT
1279 				);
1280 
1281 		musb_ep_select(mbase, epnum);
1282 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1283 		/* REVISIT may need to clear FLUSHFIFO ... */
1284 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1285 		musb_writeb(epio, MUSB_TXINTERVAL, 0);
1286 
1287 		done = true;
1288 	}
1289 
1290 	/* second cppi case */
1291 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1292 		musb_dbg(musb, "extra TX%d ready, csr %04x", epnum, tx_csr);
1293 		return;
1294 	}
1295 
1296 	if (is_dma_capable() && dma && !status) {
1297 		/*
1298 		 * DMA has completed.  But if we're using DMA mode 1 (multi
1299 		 * packet DMA), we need a terminal TXPKTRDY interrupt before
1300 		 * we can consider this transfer completed, lest we trash
1301 		 * its last packet when writing the next URB's data.  So we
1302 		 * switch back to mode 0 to get that interrupt; we'll come
1303 		 * back here once it happens.
1304 		 */
1305 		if (tx_csr & MUSB_TXCSR_DMAMODE) {
1306 			/*
1307 			 * We shouldn't clear DMAMODE with DMAENAB set; so
1308 			 * clear them in a safe order.  That should be OK
1309 			 * once TXPKTRDY has been set (and I've never seen
1310 			 * it being 0 at this moment -- DMA interrupt latency
1311 			 * is significant) but if it hasn't been then we have
1312 			 * no choice but to stop being polite and ignore the
1313 			 * programmer's guide... :-)
1314 			 *
1315 			 * Note that we must write TXCSR with TXPKTRDY cleared
1316 			 * in order not to re-trigger the packet send (this bit
1317 			 * can't be cleared by CPU), and there's another caveat:
1318 			 * TXPKTRDY may be set shortly and then cleared in the
1319 			 * double-buffered FIFO mode, so we do an extra TXCSR
1320 			 * read for debouncing...
1321 			 */
1322 			tx_csr &= musb_readw(epio, MUSB_TXCSR);
1323 			if (tx_csr & MUSB_TXCSR_TXPKTRDY) {
1324 				tx_csr &= ~(MUSB_TXCSR_DMAENAB |
1325 					    MUSB_TXCSR_TXPKTRDY);
1326 				musb_writew(epio, MUSB_TXCSR,
1327 					    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1328 			}
1329 			tx_csr &= ~(MUSB_TXCSR_DMAMODE |
1330 				    MUSB_TXCSR_TXPKTRDY);
1331 			musb_writew(epio, MUSB_TXCSR,
1332 				    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1333 
1334 			/*
1335 			 * There is no guarantee that we'll get an interrupt
1336 			 * after clearing DMAMODE as we might have done this
1337 			 * too late (after TXPKTRDY was cleared by controller).
1338 			 * Re-read TXCSR as we have spoiled its previous value.
1339 			 */
1340 			tx_csr = musb_readw(epio, MUSB_TXCSR);
1341 		}
1342 
1343 		/*
1344 		 * We may get here from a DMA completion or TXPKTRDY interrupt.
1345 		 * In any case, we must check the FIFO status here and bail out
1346 		 * only if the FIFO still has data -- that should prevent the
1347 		 * "missed" TXPKTRDY interrupts and deal with double-buffered
1348 		 * FIFO mode too...
1349 		 */
1350 		if (tx_csr & (MUSB_TXCSR_FIFONOTEMPTY | MUSB_TXCSR_TXPKTRDY)) {
1351 			musb_dbg(musb,
1352 				"DMA complete but FIFO not empty, CSR %04x",
1353 				tx_csr);
1354 			return;
1355 		}
1356 	}
1357 
1358 	if (!status || dma || usb_pipeisoc(pipe)) {
1359 		if (dma)
1360 			length = dma->actual_len;
1361 		else
1362 			length = qh->segsize;
1363 		qh->offset += length;
1364 
1365 		if (usb_pipeisoc(pipe)) {
1366 			struct usb_iso_packet_descriptor	*d;
1367 
1368 			d = urb->iso_frame_desc + qh->iso_idx;
1369 			d->actual_length = length;
1370 			d->status = status;
1371 			if (++qh->iso_idx >= urb->number_of_packets) {
1372 				done = true;
1373 			} else {
1374 				d++;
1375 				offset = d->offset;
1376 				length = d->length;
1377 			}
1378 		} else if (dma && urb->transfer_buffer_length == qh->offset) {
1379 			done = true;
1380 		} else {
1381 			/* see if we need to send more data, or ZLP */
1382 			if (qh->segsize < qh->maxpacket)
1383 				done = true;
1384 			else if (qh->offset == urb->transfer_buffer_length
1385 					&& !(urb->transfer_flags
1386 						& URB_ZERO_PACKET))
1387 				done = true;
1388 			if (!done) {
1389 				offset = qh->offset;
1390 				length = urb->transfer_buffer_length - offset;
1391 				transfer_pending = true;
1392 			}
1393 		}
1394 	}
1395 
1396 	/* urb->status != -EINPROGRESS means request has been faulted,
1397 	 * so we must abort this transfer after cleanup
1398 	 */
1399 	if (urb->status != -EINPROGRESS) {
1400 		done = true;
1401 		if (status == 0)
1402 			status = urb->status;
1403 	}
1404 
1405 	if (done) {
1406 		/* set status */
1407 		urb->status = status;
1408 		urb->actual_length = qh->offset;
1409 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_OUT);
1410 		return;
1411 	} else if ((usb_pipeisoc(pipe) || transfer_pending) && dma) {
1412 		if (musb_tx_dma_program(musb->dma_controller, hw_ep, qh, urb,
1413 				offset, length)) {
1414 			if (is_cppi_enabled(musb) || tusb_dma_omap(musb))
1415 				musb_h_tx_dma_start(hw_ep);
1416 			return;
1417 		}
1418 	} else	if (tx_csr & MUSB_TXCSR_DMAENAB) {
1419 		musb_dbg(musb, "not complete, but DMA enabled?");
1420 		return;
1421 	}
1422 
1423 	/*
1424 	 * PIO: start next packet in this URB.
1425 	 *
1426 	 * REVISIT: some docs say that when hw_ep->tx_double_buffered,
1427 	 * (and presumably, FIFO is not half-full) we should write *two*
1428 	 * packets before updating TXCSR; other docs disagree...
1429 	 */
1430 	if (length > qh->maxpacket)
1431 		length = qh->maxpacket;
1432 	/* Unmap the buffer so that CPU can use it */
1433 	usb_hcd_unmap_urb_for_dma(musb->hcd, urb);
1434 
1435 	/*
1436 	 * We need to map sg if the transfer_buffer is
1437 	 * NULL.
1438 	 */
1439 	if (!urb->transfer_buffer) {
1440 		/* sg_miter_start is already done in musb_ep_program */
1441 		if (!sg_miter_next(&qh->sg_miter)) {
1442 			dev_err(musb->controller, "error: sg list empty\n");
1443 			sg_miter_stop(&qh->sg_miter);
1444 			status = -EINVAL;
1445 			goto done;
1446 		}
1447 		length = min_t(u32, length, qh->sg_miter.length);
1448 		musb_write_fifo(hw_ep, length, qh->sg_miter.addr);
1449 		qh->sg_miter.consumed = length;
1450 		sg_miter_stop(&qh->sg_miter);
1451 	} else {
1452 		musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
1453 	}
1454 
1455 	qh->segsize = length;
1456 
1457 	musb_ep_select(mbase, epnum);
1458 	musb_writew(epio, MUSB_TXCSR,
1459 			MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
1460 }
1461 
1462 #ifdef CONFIG_USB_TI_CPPI41_DMA
1463 /* Seems to set up ISO for cppi41 and not advance len. See commit c57c41d */
1464 static int musb_rx_dma_iso_cppi41(struct dma_controller *dma,
1465 				  struct musb_hw_ep *hw_ep,
1466 				  struct musb_qh *qh,
1467 				  struct urb *urb,
1468 				  size_t len)
1469 {
1470 	struct dma_channel *channel = hw_ep->rx_channel;
1471 	void __iomem *epio = hw_ep->regs;
1472 	dma_addr_t *buf;
1473 	u32 length;
1474 	u16 val;
1475 
1476 	buf = (void *)urb->iso_frame_desc[qh->iso_idx].offset +
1477 		(u32)urb->transfer_dma;
1478 
1479 	length = urb->iso_frame_desc[qh->iso_idx].length;
1480 
1481 	val = musb_readw(epio, MUSB_RXCSR);
1482 	val |= MUSB_RXCSR_DMAENAB;
1483 	musb_writew(hw_ep->regs, MUSB_RXCSR, val);
1484 
1485 	return dma->channel_program(channel, qh->maxpacket, 0,
1486 				   (u32)buf, length);
1487 }
1488 #else
1489 static inline int musb_rx_dma_iso_cppi41(struct dma_controller *dma,
1490 					 struct musb_hw_ep *hw_ep,
1491 					 struct musb_qh *qh,
1492 					 struct urb *urb,
1493 					 size_t len)
1494 {
1495 	return false;
1496 }
1497 #endif
1498 
1499 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA) || \
1500 	defined(CONFIG_USB_TI_CPPI41_DMA)
1501 /* Host side RX (IN) using Mentor DMA works as follows:
1502 	submit_urb ->
1503 		- if queue was empty, ProgramEndpoint
1504 		- first IN token is sent out (by setting ReqPkt)
1505 	LinuxIsr -> RxReady()
1506 	/\	=> first packet is received
1507 	|	- Set in mode 0 (DmaEnab, ~ReqPkt)
1508 	|		-> DMA Isr (transfer complete) -> RxReady()
1509 	|		    - Ack receive (~RxPktRdy), turn off DMA (~DmaEnab)
1510 	|		    - if urb not complete, send next IN token (ReqPkt)
1511 	|			   |		else complete urb.
1512 	|			   |
1513 	---------------------------
1514  *
1515  * Nuances of mode 1:
1516  *	For short packets, no ack (+RxPktRdy) is sent automatically
1517  *	(even if AutoClear is ON)
1518  *	For full packets, ack (~RxPktRdy) and next IN token (+ReqPkt) is sent
1519  *	automatically => major problem, as collecting the next packet becomes
1520  *	difficult. Hence mode 1 is not used.
1521  *
1522  * REVISIT
1523  *	All we care about at this driver level is that
1524  *       (a) all URBs terminate with REQPKT cleared and fifo(s) empty;
1525  *       (b) termination conditions are: short RX, or buffer full;
1526  *       (c) fault modes include
1527  *           - iff URB_SHORT_NOT_OK, short RX status is -EREMOTEIO.
1528  *             (and that endpoint's dma queue stops immediately)
1529  *           - overflow (full, PLUS more bytes in the terminal packet)
1530  *
1531  *	So for example, usb-storage sets URB_SHORT_NOT_OK, and would
1532  *	thus be a great candidate for using mode 1 ... for all but the
1533  *	last packet of one URB's transfer.
1534  */
1535 static int musb_rx_dma_inventra_cppi41(struct dma_controller *dma,
1536 				       struct musb_hw_ep *hw_ep,
1537 				       struct musb_qh *qh,
1538 				       struct urb *urb,
1539 				       size_t len)
1540 {
1541 	struct dma_channel *channel = hw_ep->rx_channel;
1542 	void __iomem *epio = hw_ep->regs;
1543 	u16 val;
1544 	int pipe;
1545 	bool done;
1546 
1547 	pipe = urb->pipe;
1548 
1549 	if (usb_pipeisoc(pipe)) {
1550 		struct usb_iso_packet_descriptor *d;
1551 
1552 		d = urb->iso_frame_desc + qh->iso_idx;
1553 		d->actual_length = len;
1554 
1555 		/* even if there was an error, we did the dma
1556 		 * for iso_frame_desc->length
1557 		 */
1558 		if (d->status != -EILSEQ && d->status != -EOVERFLOW)
1559 			d->status = 0;
1560 
1561 		if (++qh->iso_idx >= urb->number_of_packets) {
1562 			done = true;
1563 		} else {
1564 			/* REVISIT: Why ignore return value here? */
1565 			if (musb_dma_cppi41(hw_ep->musb))
1566 				done = musb_rx_dma_iso_cppi41(dma, hw_ep, qh,
1567 							      urb, len);
1568 			done = false;
1569 		}
1570 
1571 	} else  {
1572 		/* done if urb buffer is full or short packet is recd */
1573 		done = (urb->actual_length + len >=
1574 			urb->transfer_buffer_length
1575 			|| channel->actual_len < qh->maxpacket
1576 			|| channel->rx_packet_done);
1577 	}
1578 
1579 	/* send IN token for next packet, without AUTOREQ */
1580 	if (!done) {
1581 		val = musb_readw(epio, MUSB_RXCSR);
1582 		val |= MUSB_RXCSR_H_REQPKT;
1583 		musb_writew(epio, MUSB_RXCSR, MUSB_RXCSR_H_WZC_BITS | val);
1584 	}
1585 
1586 	return done;
1587 }
1588 
1589 /* Disadvantage of using mode 1:
1590  *	It's basically usable only for mass storage class; essentially all
1591  *	other protocols also terminate transfers on short packets.
1592  *
1593  * Details:
1594  *	An extra IN token is sent at the end of the transfer (due to AUTOREQ)
1595  *	If you try to use mode 1 for (transfer_buffer_length - 512), and try
1596  *	to use the extra IN token to grab the last packet using mode 0, then
1597  *	the problem is that you cannot be sure when the device will send the
1598  *	last packet and RxPktRdy set. Sometimes the packet is recd too soon
1599  *	such that it gets lost when RxCSR is re-set at the end of the mode 1
1600  *	transfer, while sometimes it is recd just a little late so that if you
1601  *	try to configure for mode 0 soon after the mode 1 transfer is
1602  *	completed, you will find rxcount 0. Okay, so you might think why not
1603  *	wait for an interrupt when the pkt is recd. Well, you won't get any!
1604  */
1605 static int musb_rx_dma_in_inventra_cppi41(struct dma_controller *dma,
1606 					  struct musb_hw_ep *hw_ep,
1607 					  struct musb_qh *qh,
1608 					  struct urb *urb,
1609 					  size_t len,
1610 					  u8 iso_err)
1611 {
1612 	struct musb *musb = hw_ep->musb;
1613 	void __iomem *epio = hw_ep->regs;
1614 	struct dma_channel *channel = hw_ep->rx_channel;
1615 	u16 rx_count, val;
1616 	int length, pipe, done;
1617 	dma_addr_t buf;
1618 
1619 	rx_count = musb_readw(epio, MUSB_RXCOUNT);
1620 	pipe = urb->pipe;
1621 
1622 	if (usb_pipeisoc(pipe)) {
1623 		int d_status = 0;
1624 		struct usb_iso_packet_descriptor *d;
1625 
1626 		d = urb->iso_frame_desc + qh->iso_idx;
1627 
1628 		if (iso_err) {
1629 			d_status = -EILSEQ;
1630 			urb->error_count++;
1631 		}
1632 		if (rx_count > d->length) {
1633 			if (d_status == 0) {
1634 				d_status = -EOVERFLOW;
1635 				urb->error_count++;
1636 			}
1637 			musb_dbg(musb, "** OVERFLOW %d into %d",
1638 				rx_count, d->length);
1639 
1640 			length = d->length;
1641 		} else
1642 			length = rx_count;
1643 		d->status = d_status;
1644 		buf = urb->transfer_dma + d->offset;
1645 	} else {
1646 		length = rx_count;
1647 		buf = urb->transfer_dma + urb->actual_length;
1648 	}
1649 
1650 	channel->desired_mode = 0;
1651 #ifdef USE_MODE1
1652 	/* because of the issue below, mode 1 will
1653 	 * only rarely behave with correct semantics.
1654 	 */
1655 	if ((urb->transfer_flags & URB_SHORT_NOT_OK)
1656 	    && (urb->transfer_buffer_length - urb->actual_length)
1657 	    > qh->maxpacket)
1658 		channel->desired_mode = 1;
1659 	if (rx_count < hw_ep->max_packet_sz_rx) {
1660 		length = rx_count;
1661 		channel->desired_mode = 0;
1662 	} else {
1663 		length = urb->transfer_buffer_length;
1664 	}
1665 #endif
1666 
1667 	/* See comments above on disadvantages of using mode 1 */
1668 	val = musb_readw(epio, MUSB_RXCSR);
1669 	val &= ~MUSB_RXCSR_H_REQPKT;
1670 
1671 	if (channel->desired_mode == 0)
1672 		val &= ~MUSB_RXCSR_H_AUTOREQ;
1673 	else
1674 		val |= MUSB_RXCSR_H_AUTOREQ;
1675 	val |= MUSB_RXCSR_DMAENAB;
1676 
1677 	/* autoclear shouldn't be set in high bandwidth */
1678 	if (qh->hb_mult == 1)
1679 		val |= MUSB_RXCSR_AUTOCLEAR;
1680 
1681 	musb_writew(epio, MUSB_RXCSR, MUSB_RXCSR_H_WZC_BITS | val);
1682 
1683 	/* REVISIT if when actual_length != 0,
1684 	 * transfer_buffer_length needs to be
1685 	 * adjusted first...
1686 	 */
1687 	done = dma->channel_program(channel, qh->maxpacket,
1688 				   channel->desired_mode,
1689 				   buf, length);
1690 
1691 	if (!done) {
1692 		dma->channel_release(channel);
1693 		hw_ep->rx_channel = NULL;
1694 		channel = NULL;
1695 		val = musb_readw(epio, MUSB_RXCSR);
1696 		val &= ~(MUSB_RXCSR_DMAENAB
1697 			 | MUSB_RXCSR_H_AUTOREQ
1698 			 | MUSB_RXCSR_AUTOCLEAR);
1699 		musb_writew(epio, MUSB_RXCSR, val);
1700 	}
1701 
1702 	return done;
1703 }
1704 #else
1705 static inline int musb_rx_dma_inventra_cppi41(struct dma_controller *dma,
1706 					      struct musb_hw_ep *hw_ep,
1707 					      struct musb_qh *qh,
1708 					      struct urb *urb,
1709 					      size_t len)
1710 {
1711 	return false;
1712 }
1713 
1714 static inline int musb_rx_dma_in_inventra_cppi41(struct dma_controller *dma,
1715 						 struct musb_hw_ep *hw_ep,
1716 						 struct musb_qh *qh,
1717 						 struct urb *urb,
1718 						 size_t len,
1719 						 u8 iso_err)
1720 {
1721 	return false;
1722 }
1723 #endif
1724 
1725 /*
1726  * Service an RX interrupt for the given IN endpoint; docs cover bulk, iso,
1727  * and high-bandwidth IN transfer cases.
1728  */
1729 void musb_host_rx(struct musb *musb, u8 epnum)
1730 {
1731 	struct urb		*urb;
1732 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1733 	struct dma_controller	*c = musb->dma_controller;
1734 	void __iomem		*epio = hw_ep->regs;
1735 	struct musb_qh		*qh = hw_ep->in_qh;
1736 	size_t			xfer_len;
1737 	void __iomem		*mbase = musb->mregs;
1738 	u16			rx_csr, val;
1739 	bool			iso_err = false;
1740 	bool			done = false;
1741 	u32			status;
1742 	struct dma_channel	*dma;
1743 	unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
1744 
1745 	musb_ep_select(mbase, epnum);
1746 
1747 	urb = next_urb(qh);
1748 	dma = is_dma_capable() ? hw_ep->rx_channel : NULL;
1749 	status = 0;
1750 	xfer_len = 0;
1751 
1752 	rx_csr = musb_readw(epio, MUSB_RXCSR);
1753 	val = rx_csr;
1754 
1755 	if (unlikely(!urb)) {
1756 		/* REVISIT -- THIS SHOULD NEVER HAPPEN ... but, at least
1757 		 * usbtest #11 (unlinks) triggers it regularly, sometimes
1758 		 * with fifo full.  (Only with DMA??)
1759 		 */
1760 		musb_dbg(musb, "BOGUS RX%d ready, csr %04x, count %d",
1761 			epnum, val, musb_readw(epio, MUSB_RXCOUNT));
1762 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1763 		return;
1764 	}
1765 
1766 	trace_musb_urb_rx(musb, urb);
1767 
1768 	/* check for errors, concurrent stall & unlink is not really
1769 	 * handled yet! */
1770 	if (rx_csr & MUSB_RXCSR_H_RXSTALL) {
1771 		musb_dbg(musb, "RX end %d STALL", epnum);
1772 
1773 		/* stall; record URB status */
1774 		status = -EPIPE;
1775 
1776 	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
1777 		dev_err(musb->controller, "ep%d RX three-strikes error", epnum);
1778 
1779 		/*
1780 		 * The three-strikes error could only happen when the USB
1781 		 * device is not accessible, for example detached or powered
1782 		 * off. So return the fatal error -ESHUTDOWN so hopefully the
1783 		 * USB device drivers won't immediately resubmit the same URB.
1784 		 */
1785 		status = -ESHUTDOWN;
1786 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1787 
1788 		rx_csr &= ~MUSB_RXCSR_H_ERROR;
1789 		musb_writew(epio, MUSB_RXCSR, rx_csr);
1790 
1791 	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
1792 
1793 		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
1794 			musb_dbg(musb, "RX end %d NAK timeout", epnum);
1795 
1796 			/* NOTE: NAKing is *NOT* an error, so we want to
1797 			 * continue.  Except ... if there's a request for
1798 			 * another QH, use that instead of starving it.
1799 			 *
1800 			 * Devices like Ethernet and serial adapters keep
1801 			 * reads posted at all times, which will starve
1802 			 * other devices without this logic.
1803 			 */
1804 			if (usb_pipebulk(urb->pipe)
1805 					&& qh->mux == 1
1806 					&& !list_is_singular(&musb->in_bulk)) {
1807 				musb_bulk_nak_timeout(musb, hw_ep, 1);
1808 				return;
1809 			}
1810 			musb_ep_select(mbase, epnum);
1811 			rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1812 			rx_csr &= ~MUSB_RXCSR_DATAERROR;
1813 			musb_writew(epio, MUSB_RXCSR, rx_csr);
1814 
1815 			goto finish;
1816 		} else {
1817 			musb_dbg(musb, "RX end %d ISO data error", epnum);
1818 			/* packet error reported later */
1819 			iso_err = true;
1820 		}
1821 	} else if (rx_csr & MUSB_RXCSR_INCOMPRX) {
1822 		musb_dbg(musb, "end %d high bandwidth incomplete ISO packet RX",
1823 				epnum);
1824 		status = -EPROTO;
1825 	}
1826 
1827 	/* faults abort the transfer */
1828 	if (status) {
1829 		/* clean up dma and collect transfer count */
1830 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1831 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1832 			musb->dma_controller->channel_abort(dma);
1833 			xfer_len = dma->actual_len;
1834 		}
1835 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1836 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1837 		done = true;
1838 		goto finish;
1839 	}
1840 
1841 	if (unlikely(dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY)) {
1842 		/* SHOULD NEVER HAPPEN ... but at least DaVinci has done it */
1843 		ERR("RX%d dma busy, csr %04x\n", epnum, rx_csr);
1844 		goto finish;
1845 	}
1846 
1847 	/* thorough shutdown for now ... given more precise fault handling
1848 	 * and better queueing support, we might keep a DMA pipeline going
1849 	 * while processing this irq for earlier completions.
1850 	 */
1851 
1852 	/* FIXME this is _way_ too much in-line logic for Mentor DMA */
1853 	if (!musb_dma_inventra(musb) && !musb_dma_ux500(musb) &&
1854 	    (rx_csr & MUSB_RXCSR_H_REQPKT)) {
1855 		/* REVISIT this happened for a while on some short reads...
1856 		 * the cleanup still needs investigation... looks bad...
1857 		 * and also duplicates dma cleanup code above ... plus,
1858 		 * shouldn't this be the "half full" double buffer case?
1859 		 */
1860 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1861 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1862 			musb->dma_controller->channel_abort(dma);
1863 			xfer_len = dma->actual_len;
1864 			done = true;
1865 		}
1866 
1867 		musb_dbg(musb, "RXCSR%d %04x, reqpkt, len %zu%s", epnum, rx_csr,
1868 				xfer_len, dma ? ", dma" : "");
1869 		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
1870 
1871 		musb_ep_select(mbase, epnum);
1872 		musb_writew(epio, MUSB_RXCSR,
1873 				MUSB_RXCSR_H_WZC_BITS | rx_csr);
1874 	}
1875 
1876 	if (dma && (rx_csr & MUSB_RXCSR_DMAENAB)) {
1877 		xfer_len = dma->actual_len;
1878 
1879 		val &= ~(MUSB_RXCSR_DMAENAB
1880 			| MUSB_RXCSR_H_AUTOREQ
1881 			| MUSB_RXCSR_AUTOCLEAR
1882 			| MUSB_RXCSR_RXPKTRDY);
1883 		musb_writew(hw_ep->regs, MUSB_RXCSR, val);
1884 
1885 		if (musb_dma_inventra(musb) || musb_dma_ux500(musb) ||
1886 		    musb_dma_cppi41(musb)) {
1887 			    done = musb_rx_dma_inventra_cppi41(c, hw_ep, qh, urb, xfer_len);
1888 			    musb_dbg(hw_ep->musb,
1889 				    "ep %d dma %s, rxcsr %04x, rxcount %d",
1890 				    epnum, done ? "off" : "reset",
1891 				    musb_readw(epio, MUSB_RXCSR),
1892 				    musb_readw(epio, MUSB_RXCOUNT));
1893 		} else {
1894 			done = true;
1895 		}
1896 
1897 	} else if (urb->status == -EINPROGRESS) {
1898 		/* if no errors, be sure a packet is ready for unloading */
1899 		if (unlikely(!(rx_csr & MUSB_RXCSR_RXPKTRDY))) {
1900 			status = -EPROTO;
1901 			ERR("Rx interrupt with no errors or packet!\n");
1902 
1903 			/* FIXME this is another "SHOULD NEVER HAPPEN" */
1904 
1905 /* SCRUB (RX) */
1906 			/* do the proper sequence to abort the transfer */
1907 			musb_ep_select(mbase, epnum);
1908 			val &= ~MUSB_RXCSR_H_REQPKT;
1909 			musb_writew(epio, MUSB_RXCSR, val);
1910 			goto finish;
1911 		}
1912 
1913 		/* we are expecting IN packets */
1914 		if ((musb_dma_inventra(musb) || musb_dma_ux500(musb) ||
1915 		    musb_dma_cppi41(musb)) && dma) {
1916 			musb_dbg(hw_ep->musb,
1917 				"RX%d count %d, buffer 0x%llx len %d/%d",
1918 				epnum, musb_readw(epio, MUSB_RXCOUNT),
1919 				(unsigned long long) urb->transfer_dma
1920 				+ urb->actual_length,
1921 				qh->offset,
1922 				urb->transfer_buffer_length);
1923 
1924 			if (musb_rx_dma_in_inventra_cppi41(c, hw_ep, qh, urb,
1925 							   xfer_len, iso_err))
1926 				goto finish;
1927 			else
1928 				dev_err(musb->controller, "error: rx_dma failed\n");
1929 		}
1930 
1931 		if (!dma) {
1932 			unsigned int received_len;
1933 
1934 			/* Unmap the buffer so that CPU can use it */
1935 			usb_hcd_unmap_urb_for_dma(musb->hcd, urb);
1936 
1937 			/*
1938 			 * We need to map sg if the transfer_buffer is
1939 			 * NULL.
1940 			 */
1941 			if (!urb->transfer_buffer) {
1942 				qh->use_sg = true;
1943 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
1944 						sg_flags);
1945 			}
1946 
1947 			if (qh->use_sg) {
1948 				if (!sg_miter_next(&qh->sg_miter)) {
1949 					dev_err(musb->controller, "error: sg list empty\n");
1950 					sg_miter_stop(&qh->sg_miter);
1951 					status = -EINVAL;
1952 					done = true;
1953 					goto finish;
1954 				}
1955 				urb->transfer_buffer = qh->sg_miter.addr;
1956 				received_len = urb->actual_length;
1957 				qh->offset = 0x0;
1958 				done = musb_host_packet_rx(musb, urb, epnum,
1959 						iso_err);
1960 				/* Calculate the number of bytes received */
1961 				received_len = urb->actual_length -
1962 					received_len;
1963 				qh->sg_miter.consumed = received_len;
1964 				sg_miter_stop(&qh->sg_miter);
1965 			} else {
1966 				done = musb_host_packet_rx(musb, urb,
1967 						epnum, iso_err);
1968 			}
1969 			musb_dbg(musb, "read %spacket", done ? "last " : "");
1970 		}
1971 	}
1972 
1973 finish:
1974 	urb->actual_length += xfer_len;
1975 	qh->offset += xfer_len;
1976 	if (done) {
1977 		if (qh->use_sg) {
1978 			qh->use_sg = false;
1979 			urb->transfer_buffer = NULL;
1980 		}
1981 
1982 		if (urb->status == -EINPROGRESS)
1983 			urb->status = status;
1984 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
1985 	}
1986 }
1987 
1988 /* schedule nodes correspond to peripheral endpoints, like an OHCI QH.
1989  * the software schedule associates multiple such nodes with a given
1990  * host side hardware endpoint + direction; scheduling may activate
1991  * that hardware endpoint.
1992  */
1993 static int musb_schedule(
1994 	struct musb		*musb,
1995 	struct musb_qh		*qh,
1996 	int			is_in)
1997 {
1998 	int			idle = 0;
1999 	int			best_diff;
2000 	int			best_end, epnum;
2001 	struct musb_hw_ep	*hw_ep = NULL;
2002 	struct list_head	*head = NULL;
2003 	u8			toggle;
2004 	u8			txtype;
2005 	struct urb		*urb = next_urb(qh);
2006 
2007 	/* use fixed hardware for control and bulk */
2008 	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
2009 		head = &musb->control;
2010 		hw_ep = musb->control_ep;
2011 		goto success;
2012 	}
2013 
2014 	/* else, periodic transfers get muxed to other endpoints */
2015 
2016 	/*
2017 	 * We know this qh hasn't been scheduled, so all we need to do
2018 	 * is choose which hardware endpoint to put it on ...
2019 	 *
2020 	 * REVISIT what we really want here is a regular schedule tree
2021 	 * like e.g. OHCI uses.
2022 	 */
2023 	best_diff = 4096;
2024 	best_end = -1;
2025 
2026 	for (epnum = 1, hw_ep = musb->endpoints + 1;
2027 			epnum < musb->nr_endpoints;
2028 			epnum++, hw_ep++) {
2029 		int	diff;
2030 
2031 		if (musb_ep_get_qh(hw_ep, is_in) != NULL)
2032 			continue;
2033 
2034 		if (hw_ep == musb->bulk_ep)
2035 			continue;
2036 
2037 		if (is_in)
2038 			diff = hw_ep->max_packet_sz_rx;
2039 		else
2040 			diff = hw_ep->max_packet_sz_tx;
2041 		diff -= (qh->maxpacket * qh->hb_mult);
2042 
2043 		if (diff >= 0 && best_diff > diff) {
2044 
2045 			/*
2046 			 * Mentor controller has a bug in that if we schedule
2047 			 * a BULK Tx transfer on an endpoint that had earlier
2048 			 * handled ISOC then the BULK transfer has to start on
2049 			 * a zero toggle.  If the BULK transfer starts on a 1
2050 			 * toggle then this transfer will fail as the mentor
2051 			 * controller starts the Bulk transfer on a 0 toggle
2052 			 * irrespective of the programming of the toggle bits
2053 			 * in the TXCSR register.  Check for this condition
2054 			 * while allocating the EP for a Tx Bulk transfer.  If
2055 			 * so skip this EP.
2056 			 */
2057 			hw_ep = musb->endpoints + epnum;
2058 			toggle = usb_gettoggle(urb->dev, qh->epnum, !is_in);
2059 			txtype = (musb_readb(hw_ep->regs, MUSB_TXTYPE)
2060 					>> 4) & 0x3;
2061 			if (!is_in && (qh->type == USB_ENDPOINT_XFER_BULK) &&
2062 				toggle && (txtype == USB_ENDPOINT_XFER_ISOC))
2063 				continue;
2064 
2065 			best_diff = diff;
2066 			best_end = epnum;
2067 		}
2068 	}
2069 	/* use bulk reserved ep1 if no other ep is free */
2070 	if (best_end < 0 && qh->type == USB_ENDPOINT_XFER_BULK) {
2071 		hw_ep = musb->bulk_ep;
2072 		if (is_in)
2073 			head = &musb->in_bulk;
2074 		else
2075 			head = &musb->out_bulk;
2076 
2077 		/* Enable bulk RX/TX NAK timeout scheme when bulk requests are
2078 		 * multiplexed. This scheme does not work in high speed to full
2079 		 * speed scenario as NAK interrupts are not coming from a
2080 		 * full speed device connected to a high speed device.
2081 		 * NAK timeout interval is 8 (128 uframe or 16ms) for HS and
2082 		 * 4 (8 frame or 8ms) for FS device.
2083 		 */
2084 		if (qh->dev)
2085 			qh->intv_reg =
2086 				(USB_SPEED_HIGH == qh->dev->speed) ? 8 : 4;
2087 		goto success;
2088 	} else if (best_end < 0) {
2089 		dev_err(musb->controller,
2090 				"%s hwep alloc failed for %dx%d\n",
2091 				musb_ep_xfertype_string(qh->type),
2092 				qh->hb_mult, qh->maxpacket);
2093 		return -ENOSPC;
2094 	}
2095 
2096 	idle = 1;
2097 	qh->mux = 0;
2098 	hw_ep = musb->endpoints + best_end;
2099 	musb_dbg(musb, "qh %p periodic slot %d", qh, best_end);
2100 success:
2101 	if (head) {
2102 		idle = list_empty(head);
2103 		list_add_tail(&qh->ring, head);
2104 		qh->mux = 1;
2105 	}
2106 	qh->hw_ep = hw_ep;
2107 	qh->hep->hcpriv = qh;
2108 	if (idle)
2109 		musb_start_urb(musb, is_in, qh);
2110 	return 0;
2111 }
2112 
2113 static int musb_urb_enqueue(
2114 	struct usb_hcd			*hcd,
2115 	struct urb			*urb,
2116 	gfp_t				mem_flags)
2117 {
2118 	unsigned long			flags;
2119 	struct musb			*musb = hcd_to_musb(hcd);
2120 	struct usb_host_endpoint	*hep = urb->ep;
2121 	struct musb_qh			*qh;
2122 	struct usb_endpoint_descriptor	*epd = &hep->desc;
2123 	int				ret;
2124 	unsigned			type_reg;
2125 	unsigned			interval;
2126 
2127 	/* host role must be active */
2128 	if (!is_host_active(musb) || !musb->is_active)
2129 		return -ENODEV;
2130 
2131 	trace_musb_urb_enq(musb, urb);
2132 
2133 	spin_lock_irqsave(&musb->lock, flags);
2134 	ret = usb_hcd_link_urb_to_ep(hcd, urb);
2135 	qh = ret ? NULL : hep->hcpriv;
2136 	if (qh)
2137 		urb->hcpriv = qh;
2138 	spin_unlock_irqrestore(&musb->lock, flags);
2139 
2140 	/* DMA mapping was already done, if needed, and this urb is on
2141 	 * hep->urb_list now ... so we're done, unless hep wasn't yet
2142 	 * scheduled onto a live qh.
2143 	 *
2144 	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets
2145 	 * disabled, testing for empty qh->ring and avoiding qh setup costs
2146 	 * except for the first urb queued after a config change.
2147 	 */
2148 	if (qh || ret)
2149 		return ret;
2150 
2151 	/* Allocate and initialize qh, minimizing the work done each time
2152 	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.
2153 	 *
2154 	 * REVISIT consider a dedicated qh kmem_cache, so it's harder
2155 	 * for bugs in other kernel code to break this driver...
2156 	 */
2157 	qh = kzalloc(sizeof *qh, mem_flags);
2158 	if (!qh) {
2159 		spin_lock_irqsave(&musb->lock, flags);
2160 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2161 		spin_unlock_irqrestore(&musb->lock, flags);
2162 		return -ENOMEM;
2163 	}
2164 
2165 	qh->hep = hep;
2166 	qh->dev = urb->dev;
2167 	INIT_LIST_HEAD(&qh->ring);
2168 	qh->is_ready = 1;
2169 
2170 	qh->maxpacket = usb_endpoint_maxp(epd);
2171 	qh->type = usb_endpoint_type(epd);
2172 
2173 	/* Bits 11 & 12 of wMaxPacketSize encode high bandwidth multiplier.
2174 	 * Some musb cores don't support high bandwidth ISO transfers; and
2175 	 * we don't (yet!) support high bandwidth interrupt transfers.
2176 	 */
2177 	qh->hb_mult = usb_endpoint_maxp_mult(epd);
2178 	if (qh->hb_mult > 1) {
2179 		int ok = (qh->type == USB_ENDPOINT_XFER_ISOC);
2180 
2181 		if (ok)
2182 			ok = (usb_pipein(urb->pipe) && musb->hb_iso_rx)
2183 				|| (usb_pipeout(urb->pipe) && musb->hb_iso_tx);
2184 		if (!ok) {
2185 			dev_err(musb->controller,
2186 				"high bandwidth %s (%dx%d) not supported\n",
2187 				musb_ep_xfertype_string(qh->type),
2188 				qh->hb_mult, qh->maxpacket & 0x7ff);
2189 			ret = -EMSGSIZE;
2190 			goto done;
2191 		}
2192 		qh->maxpacket &= 0x7ff;
2193 	}
2194 
2195 	qh->epnum = usb_endpoint_num(epd);
2196 
2197 	/* NOTE: urb->dev->devnum is wrong during SET_ADDRESS */
2198 	qh->addr_reg = (u8) usb_pipedevice(urb->pipe);
2199 
2200 	/* precompute rxtype/txtype/type0 register */
2201 	type_reg = (qh->type << 4) | qh->epnum;
2202 	switch (urb->dev->speed) {
2203 	case USB_SPEED_LOW:
2204 		type_reg |= 0xc0;
2205 		break;
2206 	case USB_SPEED_FULL:
2207 		type_reg |= 0x80;
2208 		break;
2209 	default:
2210 		type_reg |= 0x40;
2211 	}
2212 	qh->type_reg = type_reg;
2213 
2214 	/* Precompute RXINTERVAL/TXINTERVAL register */
2215 	switch (qh->type) {
2216 	case USB_ENDPOINT_XFER_INT:
2217 		/*
2218 		 * Full/low speeds use the  linear encoding,
2219 		 * high speed uses the logarithmic encoding.
2220 		 */
2221 		if (urb->dev->speed <= USB_SPEED_FULL) {
2222 			interval = max_t(u8, epd->bInterval, 1);
2223 			break;
2224 		}
2225 		fallthrough;
2226 	case USB_ENDPOINT_XFER_ISOC:
2227 		/* ISO always uses logarithmic encoding */
2228 		interval = min_t(u8, epd->bInterval, 16);
2229 		break;
2230 	default:
2231 		/* REVISIT we actually want to use NAK limits, hinting to the
2232 		 * transfer scheduling logic to try some other qh, e.g. try
2233 		 * for 2 msec first:
2234 		 *
2235 		 * interval = (USB_SPEED_HIGH == urb->dev->speed) ? 16 : 2;
2236 		 *
2237 		 * The downside of disabling this is that transfer scheduling
2238 		 * gets VERY unfair for nonperiodic transfers; a misbehaving
2239 		 * peripheral could make that hurt.  That's perfectly normal
2240 		 * for reads from network or serial adapters ... so we have
2241 		 * partial NAKlimit support for bulk RX.
2242 		 *
2243 		 * The upside of disabling it is simpler transfer scheduling.
2244 		 */
2245 		interval = 0;
2246 	}
2247 	qh->intv_reg = interval;
2248 
2249 	/* precompute addressing for external hub/tt ports */
2250 	if (musb->is_multipoint) {
2251 		struct usb_device	*parent = urb->dev->parent;
2252 
2253 		if (parent != hcd->self.root_hub) {
2254 			qh->h_addr_reg = (u8) parent->devnum;
2255 
2256 			/* set up tt info if needed */
2257 			if (urb->dev->tt) {
2258 				qh->h_port_reg = (u8) urb->dev->ttport;
2259 				if (urb->dev->tt->hub)
2260 					qh->h_addr_reg =
2261 						(u8) urb->dev->tt->hub->devnum;
2262 				if (urb->dev->tt->multi)
2263 					qh->h_addr_reg |= 0x80;
2264 			}
2265 		}
2266 	}
2267 
2268 	/* invariant: hep->hcpriv is null OR the qh that's already scheduled.
2269 	 * until we get real dma queues (with an entry for each urb/buffer),
2270 	 * we only have work to do in the former case.
2271 	 */
2272 	spin_lock_irqsave(&musb->lock, flags);
2273 	if (hep->hcpriv || !next_urb(qh)) {
2274 		/* some concurrent activity submitted another urb to hep...
2275 		 * odd, rare, error prone, but legal.
2276 		 */
2277 		kfree(qh);
2278 		qh = NULL;
2279 		ret = 0;
2280 	} else
2281 		ret = musb_schedule(musb, qh,
2282 				epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK);
2283 
2284 	if (ret == 0) {
2285 		urb->hcpriv = qh;
2286 		/* FIXME set urb->start_frame for iso/intr, it's tested in
2287 		 * musb_start_urb(), but otherwise only konicawc cares ...
2288 		 */
2289 	}
2290 	spin_unlock_irqrestore(&musb->lock, flags);
2291 
2292 done:
2293 	if (ret != 0) {
2294 		spin_lock_irqsave(&musb->lock, flags);
2295 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2296 		spin_unlock_irqrestore(&musb->lock, flags);
2297 		kfree(qh);
2298 	}
2299 	return ret;
2300 }
2301 
2302 
2303 /*
2304  * abort a transfer that's at the head of a hardware queue.
2305  * called with controller locked, irqs blocked
2306  * that hardware queue advances to the next transfer, unless prevented
2307  */
2308 static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
2309 {
2310 	struct musb_hw_ep	*ep = qh->hw_ep;
2311 	struct musb		*musb = ep->musb;
2312 	void __iomem		*epio = ep->regs;
2313 	unsigned		hw_end = ep->epnum;
2314 	void __iomem		*regs = ep->musb->mregs;
2315 	int			is_in = usb_pipein(urb->pipe);
2316 	int			status = 0;
2317 	u16			csr;
2318 	struct dma_channel	*dma = NULL;
2319 
2320 	musb_ep_select(regs, hw_end);
2321 
2322 	if (is_dma_capable()) {
2323 		dma = is_in ? ep->rx_channel : ep->tx_channel;
2324 		if (dma) {
2325 			status = ep->musb->dma_controller->channel_abort(dma);
2326 			musb_dbg(musb, "abort %cX%d DMA for urb %p --> %d",
2327 				is_in ? 'R' : 'T', ep->epnum,
2328 				urb, status);
2329 			urb->actual_length += dma->actual_len;
2330 		}
2331 	}
2332 
2333 	/* turn off DMA requests, discard state, stop polling ... */
2334 	if (ep->epnum && is_in) {
2335 		/* giveback saves bulk toggle */
2336 		csr = musb_h_flush_rxfifo(ep, 0);
2337 
2338 		/* clear the endpoint's irq status here to avoid bogus irqs */
2339 		if (is_dma_capable() && dma)
2340 			musb_platform_clear_ep_rxintr(musb, ep->epnum);
2341 	} else if (ep->epnum) {
2342 		musb_h_tx_flush_fifo(ep);
2343 		csr = musb_readw(epio, MUSB_TXCSR);
2344 		csr &= ~(MUSB_TXCSR_AUTOSET
2345 			| MUSB_TXCSR_DMAENAB
2346 			| MUSB_TXCSR_H_RXSTALL
2347 			| MUSB_TXCSR_H_NAKTIMEOUT
2348 			| MUSB_TXCSR_H_ERROR
2349 			| MUSB_TXCSR_TXPKTRDY);
2350 		musb_writew(epio, MUSB_TXCSR, csr);
2351 		/* REVISIT may need to clear FLUSHFIFO ... */
2352 		musb_writew(epio, MUSB_TXCSR, csr);
2353 		/* flush cpu writebuffer */
2354 		csr = musb_readw(epio, MUSB_TXCSR);
2355 	} else  {
2356 		musb_h_ep0_flush_fifo(ep);
2357 	}
2358 	if (status == 0)
2359 		musb_advance_schedule(ep->musb, urb, ep, is_in);
2360 	return status;
2361 }
2362 
2363 static int musb_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
2364 {
2365 	struct musb		*musb = hcd_to_musb(hcd);
2366 	struct musb_qh		*qh;
2367 	unsigned long		flags;
2368 	int			is_in  = usb_pipein(urb->pipe);
2369 	int			ret;
2370 
2371 	trace_musb_urb_deq(musb, urb);
2372 
2373 	spin_lock_irqsave(&musb->lock, flags);
2374 	ret = usb_hcd_check_unlink_urb(hcd, urb, status);
2375 	if (ret)
2376 		goto done;
2377 
2378 	qh = urb->hcpriv;
2379 	if (!qh)
2380 		goto done;
2381 
2382 	/*
2383 	 * Any URB not actively programmed into endpoint hardware can be
2384 	 * immediately given back; that's any URB not at the head of an
2385 	 * endpoint queue, unless someday we get real DMA queues.  And even
2386 	 * if it's at the head, it might not be known to the hardware...
2387 	 *
2388 	 * Otherwise abort current transfer, pending DMA, etc.; urb->status
2389 	 * has already been updated.  This is a synchronous abort; it'd be
2390 	 * OK to hold off until after some IRQ, though.
2391 	 *
2392 	 * NOTE: qh is invalid unless !list_empty(&hep->urb_list)
2393 	 */
2394 	if (!qh->is_ready
2395 			|| urb->urb_list.prev != &qh->hep->urb_list
2396 			|| musb_ep_get_qh(qh->hw_ep, is_in) != qh) {
2397 		int	ready = qh->is_ready;
2398 
2399 		qh->is_ready = 0;
2400 		musb_giveback(musb, urb, 0);
2401 		qh->is_ready = ready;
2402 
2403 		/* If nothing else (usually musb_giveback) is using it
2404 		 * and its URB list has emptied, recycle this qh.
2405 		 */
2406 		if (ready && list_empty(&qh->hep->urb_list)) {
2407 			musb_ep_set_qh(qh->hw_ep, is_in, NULL);
2408 			qh->hep->hcpriv = NULL;
2409 			list_del(&qh->ring);
2410 			kfree(qh);
2411 		}
2412 	} else
2413 		ret = musb_cleanup_urb(urb, qh);
2414 done:
2415 	spin_unlock_irqrestore(&musb->lock, flags);
2416 	return ret;
2417 }
2418 
2419 /* disable an endpoint */
2420 static void
2421 musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
2422 {
2423 	u8			is_in = hep->desc.bEndpointAddress & USB_DIR_IN;
2424 	unsigned long		flags;
2425 	struct musb		*musb = hcd_to_musb(hcd);
2426 	struct musb_qh		*qh;
2427 	struct urb		*urb;
2428 
2429 	spin_lock_irqsave(&musb->lock, flags);
2430 
2431 	qh = hep->hcpriv;
2432 	if (qh == NULL)
2433 		goto exit;
2434 
2435 	/* NOTE: qh is invalid unless !list_empty(&hep->urb_list) */
2436 
2437 	/* Kick the first URB off the hardware, if needed */
2438 	qh->is_ready = 0;
2439 	if (musb_ep_get_qh(qh->hw_ep, is_in) == qh) {
2440 		urb = next_urb(qh);
2441 
2442 		/* make software (then hardware) stop ASAP */
2443 		if (!urb->unlinked)
2444 			urb->status = -ESHUTDOWN;
2445 
2446 		/* cleanup */
2447 		musb_cleanup_urb(urb, qh);
2448 
2449 		/* Then nuke all the others ... and advance the
2450 		 * queue on hw_ep (e.g. bulk ring) when we're done.
2451 		 */
2452 		while (!list_empty(&hep->urb_list)) {
2453 			urb = next_urb(qh);
2454 			urb->status = -ESHUTDOWN;
2455 			musb_advance_schedule(musb, urb, qh->hw_ep, is_in);
2456 		}
2457 	} else {
2458 		/* Just empty the queue; the hardware is busy with
2459 		 * other transfers, and since !qh->is_ready nothing
2460 		 * will activate any of these as it advances.
2461 		 */
2462 		while (!list_empty(&hep->urb_list))
2463 			musb_giveback(musb, next_urb(qh), -ESHUTDOWN);
2464 
2465 		hep->hcpriv = NULL;
2466 		list_del(&qh->ring);
2467 		kfree(qh);
2468 	}
2469 exit:
2470 	spin_unlock_irqrestore(&musb->lock, flags);
2471 }
2472 
2473 static int musb_h_get_frame_number(struct usb_hcd *hcd)
2474 {
2475 	struct musb	*musb = hcd_to_musb(hcd);
2476 
2477 	return musb_readw(musb->mregs, MUSB_FRAME);
2478 }
2479 
2480 static int musb_h_start(struct usb_hcd *hcd)
2481 {
2482 	struct musb	*musb = hcd_to_musb(hcd);
2483 
2484 	/* NOTE: musb_start() is called when the hub driver turns
2485 	 * on port power, or when (OTG) peripheral starts.
2486 	 */
2487 	hcd->state = HC_STATE_RUNNING;
2488 	musb->port1_status = 0;
2489 	return 0;
2490 }
2491 
2492 static void musb_h_stop(struct usb_hcd *hcd)
2493 {
2494 	musb_stop(hcd_to_musb(hcd));
2495 	hcd->state = HC_STATE_HALT;
2496 }
2497 
2498 static int musb_bus_suspend(struct usb_hcd *hcd)
2499 {
2500 	struct musb	*musb = hcd_to_musb(hcd);
2501 	u8		devctl;
2502 	int		ret;
2503 
2504 	ret = musb_port_suspend(musb, true);
2505 	if (ret)
2506 		return ret;
2507 
2508 	if (!is_host_active(musb))
2509 		return 0;
2510 
2511 	switch (musb_get_state(musb)) {
2512 	case OTG_STATE_A_SUSPEND:
2513 		return 0;
2514 	case OTG_STATE_A_WAIT_VRISE:
2515 		/* ID could be grounded even if there's no device
2516 		 * on the other end of the cable.  NOTE that the
2517 		 * A_WAIT_VRISE timers are messy with MUSB...
2518 		 */
2519 		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2520 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2521 			musb_set_state(musb, OTG_STATE_A_WAIT_BCON);
2522 		break;
2523 	default:
2524 		break;
2525 	}
2526 
2527 	if (musb->is_active) {
2528 		WARNING("trying to suspend as %s while active\n",
2529 			musb_otg_state_string(musb));
2530 		return -EBUSY;
2531 	} else
2532 		return 0;
2533 }
2534 
2535 static int musb_bus_resume(struct usb_hcd *hcd)
2536 {
2537 	struct musb *musb = hcd_to_musb(hcd);
2538 
2539 	if (musb->config &&
2540 	    musb->config->host_port_deassert_reset_at_resume)
2541 		musb_port_reset(musb, false);
2542 
2543 	return 0;
2544 }
2545 
2546 #ifndef CONFIG_MUSB_PIO_ONLY
2547 
2548 #define MUSB_USB_DMA_ALIGN 4
2549 
2550 struct musb_temp_buffer {
2551 	void *kmalloc_ptr;
2552 	void *old_xfer_buffer;
2553 	u8 data[];
2554 };
2555 
2556 static void musb_free_temp_buffer(struct urb *urb)
2557 {
2558 	enum dma_data_direction dir;
2559 	struct musb_temp_buffer *temp;
2560 	size_t length;
2561 
2562 	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
2563 		return;
2564 
2565 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2566 
2567 	temp = container_of(urb->transfer_buffer, struct musb_temp_buffer,
2568 			    data);
2569 
2570 	if (dir == DMA_FROM_DEVICE) {
2571 		if (usb_pipeisoc(urb->pipe))
2572 			length = urb->transfer_buffer_length;
2573 		else
2574 			length = urb->actual_length;
2575 
2576 		memcpy(temp->old_xfer_buffer, temp->data, length);
2577 	}
2578 	urb->transfer_buffer = temp->old_xfer_buffer;
2579 	kfree(temp->kmalloc_ptr);
2580 
2581 	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
2582 }
2583 
2584 static int musb_alloc_temp_buffer(struct urb *urb, gfp_t mem_flags)
2585 {
2586 	enum dma_data_direction dir;
2587 	struct musb_temp_buffer *temp;
2588 	void *kmalloc_ptr;
2589 	size_t kmalloc_size;
2590 
2591 	if (urb->num_sgs || urb->sg ||
2592 	    urb->transfer_buffer_length == 0 ||
2593 	    !((uintptr_t)urb->transfer_buffer & (MUSB_USB_DMA_ALIGN - 1)))
2594 		return 0;
2595 
2596 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2597 
2598 	/* Allocate a buffer with enough padding for alignment */
2599 	kmalloc_size = urb->transfer_buffer_length +
2600 		sizeof(struct musb_temp_buffer) + MUSB_USB_DMA_ALIGN - 1;
2601 
2602 	kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
2603 	if (!kmalloc_ptr)
2604 		return -ENOMEM;
2605 
2606 	/* Position our struct temp_buffer such that data is aligned */
2607 	temp = PTR_ALIGN(kmalloc_ptr, MUSB_USB_DMA_ALIGN);
2608 
2609 
2610 	temp->kmalloc_ptr = kmalloc_ptr;
2611 	temp->old_xfer_buffer = urb->transfer_buffer;
2612 	if (dir == DMA_TO_DEVICE)
2613 		memcpy(temp->data, urb->transfer_buffer,
2614 		       urb->transfer_buffer_length);
2615 	urb->transfer_buffer = temp->data;
2616 
2617 	urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
2618 
2619 	return 0;
2620 }
2621 
2622 static int musb_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
2623 				      gfp_t mem_flags)
2624 {
2625 	struct musb	*musb = hcd_to_musb(hcd);
2626 	int ret;
2627 
2628 	/*
2629 	 * The DMA engine in RTL1.8 and above cannot handle
2630 	 * DMA addresses that are not aligned to a 4 byte boundary.
2631 	 * For such engine implemented (un)map_urb_for_dma hooks.
2632 	 * Do not use these hooks for RTL<1.8
2633 	 */
2634 	if (musb->hwvers < MUSB_HWVERS_1800)
2635 		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
2636 
2637 	ret = musb_alloc_temp_buffer(urb, mem_flags);
2638 	if (ret)
2639 		return ret;
2640 
2641 	ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
2642 	if (ret)
2643 		musb_free_temp_buffer(urb);
2644 
2645 	return ret;
2646 }
2647 
2648 static void musb_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
2649 {
2650 	struct musb	*musb = hcd_to_musb(hcd);
2651 
2652 	usb_hcd_unmap_urb_for_dma(hcd, urb);
2653 
2654 	/* Do not use this hook for RTL<1.8 (see description above) */
2655 	if (musb->hwvers < MUSB_HWVERS_1800)
2656 		return;
2657 
2658 	musb_free_temp_buffer(urb);
2659 }
2660 #endif /* !CONFIG_MUSB_PIO_ONLY */
2661 
2662 static const struct hc_driver musb_hc_driver = {
2663 	.description		= "musb-hcd",
2664 	.product_desc		= "MUSB HDRC host driver",
2665 	.hcd_priv_size		= sizeof(struct musb *),
2666 	.flags			= HCD_USB2 | HCD_DMA | HCD_MEMORY,
2667 
2668 	/* not using irq handler or reset hooks from usbcore, since
2669 	 * those must be shared with peripheral code for OTG configs
2670 	 */
2671 
2672 	.start			= musb_h_start,
2673 	.stop			= musb_h_stop,
2674 
2675 	.get_frame_number	= musb_h_get_frame_number,
2676 
2677 	.urb_enqueue		= musb_urb_enqueue,
2678 	.urb_dequeue		= musb_urb_dequeue,
2679 	.endpoint_disable	= musb_h_disable,
2680 
2681 #ifndef CONFIG_MUSB_PIO_ONLY
2682 	.map_urb_for_dma	= musb_map_urb_for_dma,
2683 	.unmap_urb_for_dma	= musb_unmap_urb_for_dma,
2684 #endif
2685 
2686 	.hub_status_data	= musb_hub_status_data,
2687 	.hub_control		= musb_hub_control,
2688 	.bus_suspend		= musb_bus_suspend,
2689 	.bus_resume		= musb_bus_resume,
2690 	/* .start_port_reset	= NULL, */
2691 	/* .hub_irq_enable	= NULL, */
2692 };
2693 
2694 int musb_host_alloc(struct musb *musb)
2695 {
2696 	struct device	*dev = musb->controller;
2697 
2698 	/* usbcore sets dev->driver_data to hcd, and sometimes uses that... */
2699 	musb->hcd = usb_create_hcd(&musb_hc_driver, dev, dev_name(dev));
2700 	if (!musb->hcd)
2701 		return -EINVAL;
2702 
2703 	*musb->hcd->hcd_priv = (unsigned long) musb;
2704 	musb->hcd->self.uses_pio_for_control = 1;
2705 	musb->hcd->uses_new_polling = 1;
2706 	musb->hcd->has_tt = 1;
2707 
2708 	return 0;
2709 }
2710 
2711 void musb_host_cleanup(struct musb *musb)
2712 {
2713 	if (musb->port_mode == MUSB_PERIPHERAL)
2714 		return;
2715 	usb_remove_hcd(musb->hcd);
2716 }
2717 
2718 void musb_host_free(struct musb *musb)
2719 {
2720 	usb_put_hcd(musb->hcd);
2721 }
2722 
2723 int musb_host_setup(struct musb *musb, int power_budget)
2724 {
2725 	int ret;
2726 	struct usb_hcd *hcd = musb->hcd;
2727 
2728 	if (musb->port_mode == MUSB_HOST) {
2729 		MUSB_HST_MODE(musb);
2730 		musb_set_state(musb, OTG_STATE_A_IDLE);
2731 	}
2732 
2733 	if (musb->xceiv) {
2734 		otg_set_host(musb->xceiv->otg, &hcd->self);
2735 		musb->xceiv->otg->host = &hcd->self;
2736 	} else {
2737 		phy_set_mode(musb->phy, PHY_MODE_USB_HOST);
2738 	}
2739 
2740 	/* don't support otg protocols */
2741 	hcd->self.otg_port = 0;
2742 	hcd->power_budget = 2 * (power_budget ? : 250);
2743 	hcd->skip_phy_initialization = 1;
2744 
2745 	ret = usb_add_hcd(hcd, 0, 0);
2746 	if (ret < 0)
2747 		return ret;
2748 
2749 	device_wakeup_enable(hcd->self.controller);
2750 	return 0;
2751 }
2752 
2753 void musb_host_resume_root_hub(struct musb *musb)
2754 {
2755 	usb_hcd_resume_root_hub(musb->hcd);
2756 }
2757 
2758 void musb_host_poke_root_hub(struct musb *musb)
2759 {
2760 	MUSB_HST_MODE(musb);
2761 	if (musb->hcd->status_urb)
2762 		usb_hcd_poll_rh_status(musb->hcd);
2763 	else
2764 		usb_hcd_resume_root_hub(musb->hcd);
2765 }
2766