xref: /linux/drivers/usb/musb/musb_host.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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_t(u32, hw_ep->max_packet_sz_tx, len);
802 		else
803 			load_count = min_t(u32, packet_sz, len);
804 
805 		if (dma_channel && musb_tx_dma_program(dma_controller,
806 					hw_ep, qh, urb, offset, len))
807 			load_count = 0;
808 
809 		if (load_count) {
810 			/* PIO to load FIFO */
811 			qh->segsize = load_count;
812 			if (!buf) {
813 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
814 						SG_MITER_ATOMIC
815 						| SG_MITER_FROM_SG);
816 				if (!sg_miter_next(&qh->sg_miter)) {
817 					dev_err(musb->controller,
818 							"error: sg"
819 							"list empty\n");
820 					sg_miter_stop(&qh->sg_miter);
821 					goto finish;
822 				}
823 				buf = qh->sg_miter.addr + urb->sg->offset +
824 					urb->actual_length;
825 				load_count = min_t(u32, load_count,
826 						qh->sg_miter.length);
827 				musb_write_fifo(hw_ep, load_count, buf);
828 				qh->sg_miter.consumed = load_count;
829 				sg_miter_stop(&qh->sg_miter);
830 			} else
831 				musb_write_fifo(hw_ep, load_count, buf);
832 		}
833 finish:
834 		/* re-enable interrupt */
835 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
836 
837 	/* IN/receive */
838 	} else {
839 		u16 csr = 0;
840 
841 		if (hw_ep->rx_reinit) {
842 			musb_rx_reinit(musb, qh, epnum);
843 			csr |= musb->io.set_toggle(qh, is_out, urb);
844 
845 			if (qh->type == USB_ENDPOINT_XFER_INT)
846 				csr |= MUSB_RXCSR_DISNYET;
847 
848 		} else {
849 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
850 
851 			if (csr & (MUSB_RXCSR_RXPKTRDY
852 					| MUSB_RXCSR_DMAENAB
853 					| MUSB_RXCSR_H_REQPKT))
854 				ERR("broken !rx_reinit, ep%d csr %04x\n",
855 						hw_ep->epnum, csr);
856 
857 			/* scrub any stale state, leaving toggle alone */
858 			csr &= MUSB_RXCSR_DISNYET;
859 		}
860 
861 		/* kick things off */
862 
863 		if ((is_cppi_enabled(musb) || tusb_dma_omap(musb)) && dma_channel) {
864 			/* Candidate for DMA */
865 			dma_channel->actual_len = 0L;
866 			qh->segsize = len;
867 
868 			/* AUTOREQ is in a DMA register */
869 			musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
870 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
871 
872 			/*
873 			 * Unless caller treats short RX transfers as
874 			 * errors, we dare not queue multiple transfers.
875 			 */
876 			dma_ok = dma_controller->channel_program(dma_channel,
877 					packet_sz, !(urb->transfer_flags &
878 						     URB_SHORT_NOT_OK),
879 					urb->transfer_dma + offset,
880 					qh->segsize);
881 			if (!dma_ok) {
882 				dma_controller->channel_release(dma_channel);
883 				hw_ep->rx_channel = dma_channel = NULL;
884 			} else
885 				csr |= MUSB_RXCSR_DMAENAB;
886 		}
887 
888 		csr |= MUSB_RXCSR_H_REQPKT;
889 		musb_dbg(musb, "RXCSR%d := %04x", epnum, csr);
890 		musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
891 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
892 	}
893 }
894 
895 /* Schedule next QH from musb->in_bulk/out_bulk and move the current qh to
896  * the end; avoids starvation for other endpoints.
897  */
898 static void musb_bulk_nak_timeout(struct musb *musb, struct musb_hw_ep *ep,
899 	int is_in)
900 {
901 	struct dma_channel	*dma;
902 	struct urb		*urb;
903 	void __iomem		*mbase = musb->mregs;
904 	void __iomem		*epio = ep->regs;
905 	struct musb_qh		*cur_qh, *next_qh;
906 	u16			rx_csr, tx_csr;
907 	u16			toggle;
908 
909 	musb_ep_select(mbase, ep->epnum);
910 	if (is_in) {
911 		dma = is_dma_capable() ? ep->rx_channel : NULL;
912 
913 		/*
914 		 * Need to stop the transaction by clearing REQPKT first
915 		 * then the NAK Timeout bit ref MUSBMHDRC USB 2.0 HIGH-SPEED
916 		 * DUAL-ROLE CONTROLLER Programmer's Guide, section 9.2.2
917 		 */
918 		rx_csr = musb_readw(epio, MUSB_RXCSR);
919 		rx_csr |= MUSB_RXCSR_H_WZC_BITS;
920 		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
921 		musb_writew(epio, MUSB_RXCSR, rx_csr);
922 		rx_csr &= ~MUSB_RXCSR_DATAERROR;
923 		musb_writew(epio, MUSB_RXCSR, rx_csr);
924 
925 		cur_qh = first_qh(&musb->in_bulk);
926 	} else {
927 		dma = is_dma_capable() ? ep->tx_channel : NULL;
928 
929 		/* clear nak timeout bit */
930 		tx_csr = musb_readw(epio, MUSB_TXCSR);
931 		tx_csr |= MUSB_TXCSR_H_WZC_BITS;
932 		tx_csr &= ~MUSB_TXCSR_H_NAKTIMEOUT;
933 		musb_writew(epio, MUSB_TXCSR, tx_csr);
934 
935 		cur_qh = first_qh(&musb->out_bulk);
936 	}
937 	if (cur_qh) {
938 		urb = next_urb(cur_qh);
939 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
940 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
941 			musb->dma_controller->channel_abort(dma);
942 			urb->actual_length += dma->actual_len;
943 			dma->actual_len = 0L;
944 		}
945 		toggle = musb->io.get_toggle(cur_qh, !is_in);
946 		usb_settoggle(urb->dev, cur_qh->epnum, !is_in, toggle ? 1 : 0);
947 
948 		if (is_in) {
949 			/* move cur_qh to end of queue */
950 			list_move_tail(&cur_qh->ring, &musb->in_bulk);
951 
952 			/* get the next qh from musb->in_bulk */
953 			next_qh = first_qh(&musb->in_bulk);
954 
955 			/* set rx_reinit and schedule the next qh */
956 			ep->rx_reinit = 1;
957 		} else {
958 			/* move cur_qh to end of queue */
959 			list_move_tail(&cur_qh->ring, &musb->out_bulk);
960 
961 			/* get the next qh from musb->out_bulk */
962 			next_qh = first_qh(&musb->out_bulk);
963 
964 			/* set tx_reinit and schedule the next qh */
965 			ep->tx_reinit = 1;
966 		}
967 
968 		if (next_qh)
969 			musb_start_urb(musb, is_in, next_qh);
970 	}
971 }
972 
973 /*
974  * Service the default endpoint (ep0) as host.
975  * Return true until it's time to start the status stage.
976  */
977 static bool musb_h_ep0_continue(struct musb *musb, u16 len, struct urb *urb)
978 {
979 	bool			 more = false;
980 	u8			*fifo_dest = NULL;
981 	u16			fifo_count = 0;
982 	struct musb_hw_ep	*hw_ep = musb->control_ep;
983 	struct musb_qh		*qh = hw_ep->in_qh;
984 	struct usb_ctrlrequest	*request;
985 
986 	switch (musb->ep0_stage) {
987 	case MUSB_EP0_IN:
988 		fifo_dest = urb->transfer_buffer + urb->actual_length;
989 		fifo_count = min_t(size_t, len, urb->transfer_buffer_length -
990 				   urb->actual_length);
991 		if (fifo_count < len)
992 			urb->status = -EOVERFLOW;
993 
994 		musb_read_fifo(hw_ep, fifo_count, fifo_dest);
995 
996 		urb->actual_length += fifo_count;
997 		if (len < qh->maxpacket) {
998 			/* always terminate on short read; it's
999 			 * rarely reported as an error.
1000 			 */
1001 		} else if (urb->actual_length <
1002 				urb->transfer_buffer_length)
1003 			more = true;
1004 		break;
1005 	case MUSB_EP0_START:
1006 		request = (struct usb_ctrlrequest *) urb->setup_packet;
1007 
1008 		if (!request->wLength) {
1009 			musb_dbg(musb, "start no-DATA");
1010 			break;
1011 		} else if (request->bRequestType & USB_DIR_IN) {
1012 			musb_dbg(musb, "start IN-DATA");
1013 			musb->ep0_stage = MUSB_EP0_IN;
1014 			more = true;
1015 			break;
1016 		} else {
1017 			musb_dbg(musb, "start OUT-DATA");
1018 			musb->ep0_stage = MUSB_EP0_OUT;
1019 			more = true;
1020 		}
1021 		fallthrough;
1022 	case MUSB_EP0_OUT:
1023 		fifo_count = min_t(size_t, qh->maxpacket,
1024 				   urb->transfer_buffer_length -
1025 				   urb->actual_length);
1026 		if (fifo_count) {
1027 			fifo_dest = (u8 *) (urb->transfer_buffer
1028 					+ urb->actual_length);
1029 			musb_dbg(musb, "Sending %d byte%s to ep0 fifo %p",
1030 					fifo_count,
1031 					(fifo_count == 1) ? "" : "s",
1032 					fifo_dest);
1033 			musb_write_fifo(hw_ep, fifo_count, fifo_dest);
1034 
1035 			urb->actual_length += fifo_count;
1036 			more = true;
1037 		}
1038 		break;
1039 	default:
1040 		ERR("bogus ep0 stage %d\n", musb->ep0_stage);
1041 		break;
1042 	}
1043 
1044 	return more;
1045 }
1046 
1047 /*
1048  * Handle default endpoint interrupt as host. Only called in IRQ time
1049  * from musb_interrupt().
1050  *
1051  * called with controller irqlocked
1052  */
1053 irqreturn_t musb_h_ep0_irq(struct musb *musb)
1054 {
1055 	struct urb		*urb;
1056 	u16			csr, len;
1057 	int			status = 0;
1058 	void __iomem		*mbase = musb->mregs;
1059 	struct musb_hw_ep	*hw_ep = musb->control_ep;
1060 	void __iomem		*epio = hw_ep->regs;
1061 	struct musb_qh		*qh = hw_ep->in_qh;
1062 	bool			complete = false;
1063 	irqreturn_t		retval = IRQ_NONE;
1064 
1065 	/* ep0 only has one queue, "in" */
1066 	urb = next_urb(qh);
1067 
1068 	musb_ep_select(mbase, 0);
1069 	csr = musb_readw(epio, MUSB_CSR0);
1070 	len = (csr & MUSB_CSR0_RXPKTRDY)
1071 			? musb_readb(epio, MUSB_COUNT0)
1072 			: 0;
1073 
1074 	musb_dbg(musb, "<== csr0 %04x, qh %p, count %d, urb %p, stage %d",
1075 		csr, qh, len, urb, musb->ep0_stage);
1076 
1077 	/* if we just did status stage, we are done */
1078 	if (MUSB_EP0_STATUS == musb->ep0_stage) {
1079 		retval = IRQ_HANDLED;
1080 		complete = true;
1081 	}
1082 
1083 	/* prepare status */
1084 	if (csr & MUSB_CSR0_H_RXSTALL) {
1085 		musb_dbg(musb, "STALLING ENDPOINT");
1086 		status = -EPIPE;
1087 
1088 	} else if (csr & MUSB_CSR0_H_ERROR) {
1089 		musb_dbg(musb, "no response, csr0 %04x", csr);
1090 		status = -EPROTO;
1091 
1092 	} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
1093 		musb_dbg(musb, "control NAK timeout");
1094 
1095 		/* NOTE:  this code path would be a good place to PAUSE a
1096 		 * control transfer, if another one is queued, so that
1097 		 * ep0 is more likely to stay busy.  That's already done
1098 		 * for bulk RX transfers.
1099 		 *
1100 		 * if (qh->ring.next != &musb->control), then
1101 		 * we have a candidate... NAKing is *NOT* an error
1102 		 */
1103 		musb_writew(epio, MUSB_CSR0, 0);
1104 		retval = IRQ_HANDLED;
1105 	}
1106 
1107 	if (status) {
1108 		musb_dbg(musb, "aborting");
1109 		retval = IRQ_HANDLED;
1110 		if (urb)
1111 			urb->status = status;
1112 		complete = true;
1113 
1114 		/* use the proper sequence to abort the transfer */
1115 		if (csr & MUSB_CSR0_H_REQPKT) {
1116 			csr &= ~MUSB_CSR0_H_REQPKT;
1117 			musb_writew(epio, MUSB_CSR0, csr);
1118 			csr &= ~MUSB_CSR0_H_NAKTIMEOUT;
1119 			musb_writew(epio, MUSB_CSR0, csr);
1120 		} else {
1121 			musb_h_ep0_flush_fifo(hw_ep);
1122 		}
1123 
1124 		musb_writeb(epio, MUSB_NAKLIMIT0, 0);
1125 
1126 		/* clear it */
1127 		musb_writew(epio, MUSB_CSR0, 0);
1128 	}
1129 
1130 	if (unlikely(!urb)) {
1131 		/* stop endpoint since we have no place for its data, this
1132 		 * SHOULD NEVER HAPPEN! */
1133 		ERR("no URB for end 0\n");
1134 
1135 		musb_h_ep0_flush_fifo(hw_ep);
1136 		goto done;
1137 	}
1138 
1139 	if (!complete) {
1140 		/* call common logic and prepare response */
1141 		if (musb_h_ep0_continue(musb, len, urb)) {
1142 			/* more packets required */
1143 			csr = (MUSB_EP0_IN == musb->ep0_stage)
1144 				?  MUSB_CSR0_H_REQPKT : MUSB_CSR0_TXPKTRDY;
1145 		} else {
1146 			/* data transfer complete; perform status phase */
1147 			if (usb_pipeout(urb->pipe)
1148 					|| !urb->transfer_buffer_length)
1149 				csr = MUSB_CSR0_H_STATUSPKT
1150 					| MUSB_CSR0_H_REQPKT;
1151 			else
1152 				csr = MUSB_CSR0_H_STATUSPKT
1153 					| MUSB_CSR0_TXPKTRDY;
1154 
1155 			/* disable ping token in status phase */
1156 			csr |= MUSB_CSR0_H_DIS_PING;
1157 
1158 			/* flag status stage */
1159 			musb->ep0_stage = MUSB_EP0_STATUS;
1160 
1161 			musb_dbg(musb, "ep0 STATUS, csr %04x", csr);
1162 
1163 		}
1164 		musb_writew(epio, MUSB_CSR0, csr);
1165 		retval = IRQ_HANDLED;
1166 	} else
1167 		musb->ep0_stage = MUSB_EP0_IDLE;
1168 
1169 	/* call completion handler if done */
1170 	if (complete)
1171 		musb_advance_schedule(musb, urb, hw_ep, 1);
1172 done:
1173 	return retval;
1174 }
1175 
1176 
1177 #ifdef CONFIG_USB_INVENTRA_DMA
1178 
1179 /* Host side TX (OUT) using Mentor DMA works as follows:
1180 	submit_urb ->
1181 		- if queue was empty, Program Endpoint
1182 		- ... which starts DMA to fifo in mode 1 or 0
1183 
1184 	DMA Isr (transfer complete) -> TxAvail()
1185 		- Stop DMA (~DmaEnab)	(<--- Alert ... currently happens
1186 					only in musb_cleanup_urb)
1187 		- TxPktRdy has to be set in mode 0 or for
1188 			short packets in mode 1.
1189 */
1190 
1191 #endif
1192 
1193 /* Service a Tx-Available or dma completion irq for the endpoint */
1194 void musb_host_tx(struct musb *musb, u8 epnum)
1195 {
1196 	int			pipe;
1197 	bool			done = false;
1198 	u16			tx_csr;
1199 	size_t			length = 0;
1200 	size_t			offset = 0;
1201 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1202 	void __iomem		*epio = hw_ep->regs;
1203 	struct musb_qh		*qh = hw_ep->out_qh;
1204 	struct urb		*urb = next_urb(qh);
1205 	u32			status = 0;
1206 	void __iomem		*mbase = musb->mregs;
1207 	struct dma_channel	*dma;
1208 	bool			transfer_pending = false;
1209 
1210 	musb_ep_select(mbase, epnum);
1211 	tx_csr = musb_readw(epio, MUSB_TXCSR);
1212 
1213 	/* with CPPI, DMA sometimes triggers "extra" irqs */
1214 	if (!urb) {
1215 		musb_dbg(musb, "extra TX%d ready, csr %04x", epnum, tx_csr);
1216 		return;
1217 	}
1218 
1219 	pipe = urb->pipe;
1220 	dma = is_dma_capable() ? hw_ep->tx_channel : NULL;
1221 	trace_musb_urb_tx(musb, urb);
1222 	musb_dbg(musb, "OUT/TX%d end, csr %04x%s", epnum, tx_csr,
1223 			dma ? ", dma" : "");
1224 
1225 	/* check for errors */
1226 	if (tx_csr & MUSB_TXCSR_H_RXSTALL) {
1227 		/* dma was disabled, fifo flushed */
1228 		musb_dbg(musb, "TX end %d stall", epnum);
1229 
1230 		/* stall; record URB status */
1231 		status = -EPIPE;
1232 
1233 	} else if (tx_csr & MUSB_TXCSR_H_ERROR) {
1234 		/* (NON-ISO) dma was disabled, fifo flushed */
1235 		musb_dbg(musb, "TX 3strikes on ep=%d", epnum);
1236 
1237 		status = -ETIMEDOUT;
1238 
1239 	} else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) {
1240 		if (USB_ENDPOINT_XFER_BULK == qh->type && qh->mux == 1
1241 				&& !list_is_singular(&musb->out_bulk)) {
1242 			musb_dbg(musb, "NAK timeout on TX%d ep", epnum);
1243 			musb_bulk_nak_timeout(musb, hw_ep, 0);
1244 		} else {
1245 			musb_dbg(musb, "TX ep%d device not responding", epnum);
1246 			/* NOTE:  this code path would be a good place to PAUSE a
1247 			 * transfer, if there's some other (nonperiodic) tx urb
1248 			 * that could use this fifo.  (dma complicates it...)
1249 			 * That's already done for bulk RX transfers.
1250 			 *
1251 			 * if (bulk && qh->ring.next != &musb->out_bulk), then
1252 			 * we have a candidate... NAKing is *NOT* an error
1253 			 */
1254 			musb_ep_select(mbase, epnum);
1255 			musb_writew(epio, MUSB_TXCSR,
1256 					MUSB_TXCSR_H_WZC_BITS
1257 					| MUSB_TXCSR_TXPKTRDY);
1258 		}
1259 		return;
1260 	}
1261 
1262 done:
1263 	if (status) {
1264 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1265 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1266 			musb->dma_controller->channel_abort(dma);
1267 		}
1268 
1269 		/* do the proper sequence to abort the transfer in the
1270 		 * usb core; the dma engine should already be stopped.
1271 		 */
1272 		musb_h_tx_flush_fifo(hw_ep);
1273 		tx_csr &= ~(MUSB_TXCSR_AUTOSET
1274 				| MUSB_TXCSR_DMAENAB
1275 				| MUSB_TXCSR_H_ERROR
1276 				| MUSB_TXCSR_H_RXSTALL
1277 				| MUSB_TXCSR_H_NAKTIMEOUT
1278 				);
1279 
1280 		musb_ep_select(mbase, epnum);
1281 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1282 		/* REVISIT may need to clear FLUSHFIFO ... */
1283 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1284 		musb_writeb(epio, MUSB_TXINTERVAL, 0);
1285 
1286 		done = true;
1287 	}
1288 
1289 	/* second cppi case */
1290 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1291 		musb_dbg(musb, "extra TX%d ready, csr %04x", epnum, tx_csr);
1292 		return;
1293 	}
1294 
1295 	if (is_dma_capable() && dma && !status) {
1296 		/*
1297 		 * DMA has completed.  But if we're using DMA mode 1 (multi
1298 		 * packet DMA), we need a terminal TXPKTRDY interrupt before
1299 		 * we can consider this transfer completed, lest we trash
1300 		 * its last packet when writing the next URB's data.  So we
1301 		 * switch back to mode 0 to get that interrupt; we'll come
1302 		 * back here once it happens.
1303 		 */
1304 		if (tx_csr & MUSB_TXCSR_DMAMODE) {
1305 			/*
1306 			 * We shouldn't clear DMAMODE with DMAENAB set; so
1307 			 * clear them in a safe order.  That should be OK
1308 			 * once TXPKTRDY has been set (and I've never seen
1309 			 * it being 0 at this moment -- DMA interrupt latency
1310 			 * is significant) but if it hasn't been then we have
1311 			 * no choice but to stop being polite and ignore the
1312 			 * programmer's guide... :-)
1313 			 *
1314 			 * Note that we must write TXCSR with TXPKTRDY cleared
1315 			 * in order not to re-trigger the packet send (this bit
1316 			 * can't be cleared by CPU), and there's another caveat:
1317 			 * TXPKTRDY may be set shortly and then cleared in the
1318 			 * double-buffered FIFO mode, so we do an extra TXCSR
1319 			 * read for debouncing...
1320 			 */
1321 			tx_csr &= musb_readw(epio, MUSB_TXCSR);
1322 			if (tx_csr & MUSB_TXCSR_TXPKTRDY) {
1323 				tx_csr &= ~(MUSB_TXCSR_DMAENAB |
1324 					    MUSB_TXCSR_TXPKTRDY);
1325 				musb_writew(epio, MUSB_TXCSR,
1326 					    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1327 			}
1328 			tx_csr &= ~(MUSB_TXCSR_DMAMODE |
1329 				    MUSB_TXCSR_TXPKTRDY);
1330 			musb_writew(epio, MUSB_TXCSR,
1331 				    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1332 
1333 			/*
1334 			 * There is no guarantee that we'll get an interrupt
1335 			 * after clearing DMAMODE as we might have done this
1336 			 * too late (after TXPKTRDY was cleared by controller).
1337 			 * Re-read TXCSR as we have spoiled its previous value.
1338 			 */
1339 			tx_csr = musb_readw(epio, MUSB_TXCSR);
1340 		}
1341 
1342 		/*
1343 		 * We may get here from a DMA completion or TXPKTRDY interrupt.
1344 		 * In any case, we must check the FIFO status here and bail out
1345 		 * only if the FIFO still has data -- that should prevent the
1346 		 * "missed" TXPKTRDY interrupts and deal with double-buffered
1347 		 * FIFO mode too...
1348 		 */
1349 		if (tx_csr & (MUSB_TXCSR_FIFONOTEMPTY | MUSB_TXCSR_TXPKTRDY)) {
1350 			musb_dbg(musb,
1351 				"DMA complete but FIFO not empty, CSR %04x",
1352 				tx_csr);
1353 			return;
1354 		}
1355 	}
1356 
1357 	if (!status || dma || usb_pipeisoc(pipe)) {
1358 		if (dma)
1359 			length = dma->actual_len;
1360 		else
1361 			length = qh->segsize;
1362 		qh->offset += length;
1363 
1364 		if (usb_pipeisoc(pipe)) {
1365 			struct usb_iso_packet_descriptor	*d;
1366 
1367 			d = urb->iso_frame_desc + qh->iso_idx;
1368 			d->actual_length = length;
1369 			d->status = status;
1370 			if (++qh->iso_idx >= urb->number_of_packets) {
1371 				done = true;
1372 			} else {
1373 				d++;
1374 				offset = d->offset;
1375 				length = d->length;
1376 			}
1377 		} else if (dma && urb->transfer_buffer_length == qh->offset) {
1378 			done = true;
1379 		} else {
1380 			/* see if we need to send more data, or ZLP */
1381 			if (qh->segsize < qh->maxpacket)
1382 				done = true;
1383 			else if (qh->offset == urb->transfer_buffer_length
1384 					&& !(urb->transfer_flags
1385 						& URB_ZERO_PACKET))
1386 				done = true;
1387 			if (!done) {
1388 				offset = qh->offset;
1389 				length = urb->transfer_buffer_length - offset;
1390 				transfer_pending = true;
1391 			}
1392 		}
1393 	}
1394 
1395 	/* urb->status != -EINPROGRESS means request has been faulted,
1396 	 * so we must abort this transfer after cleanup
1397 	 */
1398 	if (urb->status != -EINPROGRESS) {
1399 		done = true;
1400 		if (status == 0)
1401 			status = urb->status;
1402 	}
1403 
1404 	if (done) {
1405 		/* set status */
1406 		urb->status = status;
1407 		urb->actual_length = qh->offset;
1408 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_OUT);
1409 		return;
1410 	} else if ((usb_pipeisoc(pipe) || transfer_pending) && dma) {
1411 		if (musb_tx_dma_program(musb->dma_controller, hw_ep, qh, urb,
1412 				offset, length)) {
1413 			if (is_cppi_enabled(musb) || tusb_dma_omap(musb))
1414 				musb_h_tx_dma_start(hw_ep);
1415 			return;
1416 		}
1417 	} else	if (tx_csr & MUSB_TXCSR_DMAENAB) {
1418 		musb_dbg(musb, "not complete, but DMA enabled?");
1419 		return;
1420 	}
1421 
1422 	/*
1423 	 * PIO: start next packet in this URB.
1424 	 *
1425 	 * REVISIT: some docs say that when hw_ep->tx_double_buffered,
1426 	 * (and presumably, FIFO is not half-full) we should write *two*
1427 	 * packets before updating TXCSR; other docs disagree...
1428 	 */
1429 	if (length > qh->maxpacket)
1430 		length = qh->maxpacket;
1431 	/* Unmap the buffer so that CPU can use it */
1432 	usb_hcd_unmap_urb_for_dma(musb->hcd, urb);
1433 
1434 	/*
1435 	 * We need to map sg if the transfer_buffer is
1436 	 * NULL.
1437 	 */
1438 	if (!urb->transfer_buffer) {
1439 		/* sg_miter_start is already done in musb_ep_program */
1440 		if (!sg_miter_next(&qh->sg_miter)) {
1441 			dev_err(musb->controller, "error: sg list empty\n");
1442 			sg_miter_stop(&qh->sg_miter);
1443 			status = -EINVAL;
1444 			goto done;
1445 		}
1446 		length = min_t(u32, length, qh->sg_miter.length);
1447 		musb_write_fifo(hw_ep, length, qh->sg_miter.addr);
1448 		qh->sg_miter.consumed = length;
1449 		sg_miter_stop(&qh->sg_miter);
1450 	} else {
1451 		musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
1452 	}
1453 
1454 	qh->segsize = length;
1455 
1456 	musb_ep_select(mbase, epnum);
1457 	musb_writew(epio, MUSB_TXCSR,
1458 			MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
1459 }
1460 
1461 #ifdef CONFIG_USB_TI_CPPI41_DMA
1462 /* Seems to set up ISO for cppi41 and not advance len. See commit c57c41d */
1463 static int musb_rx_dma_iso_cppi41(struct dma_controller *dma,
1464 				  struct musb_hw_ep *hw_ep,
1465 				  struct musb_qh *qh,
1466 				  struct urb *urb,
1467 				  size_t len)
1468 {
1469 	struct dma_channel *channel = hw_ep->rx_channel;
1470 	void __iomem *epio = hw_ep->regs;
1471 	dma_addr_t *buf;
1472 	u32 length;
1473 	u16 val;
1474 
1475 	buf = (void *)urb->iso_frame_desc[qh->iso_idx].offset +
1476 		(u32)urb->transfer_dma;
1477 
1478 	length = urb->iso_frame_desc[qh->iso_idx].length;
1479 
1480 	val = musb_readw(epio, MUSB_RXCSR);
1481 	val |= MUSB_RXCSR_DMAENAB;
1482 	musb_writew(hw_ep->regs, MUSB_RXCSR, val);
1483 
1484 	return dma->channel_program(channel, qh->maxpacket, 0,
1485 				   (u32)buf, length);
1486 }
1487 #else
1488 static inline int musb_rx_dma_iso_cppi41(struct dma_controller *dma,
1489 					 struct musb_hw_ep *hw_ep,
1490 					 struct musb_qh *qh,
1491 					 struct urb *urb,
1492 					 size_t len)
1493 {
1494 	return false;
1495 }
1496 #endif
1497 
1498 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA) || \
1499 	defined(CONFIG_USB_TI_CPPI41_DMA)
1500 /* Host side RX (IN) using Mentor DMA works as follows:
1501 	submit_urb ->
1502 		- if queue was empty, ProgramEndpoint
1503 		- first IN token is sent out (by setting ReqPkt)
1504 	LinuxIsr -> RxReady()
1505 	/\	=> first packet is received
1506 	|	- Set in mode 0 (DmaEnab, ~ReqPkt)
1507 	|		-> DMA Isr (transfer complete) -> RxReady()
1508 	|		    - Ack receive (~RxPktRdy), turn off DMA (~DmaEnab)
1509 	|		    - if urb not complete, send next IN token (ReqPkt)
1510 	|			   |		else complete urb.
1511 	|			   |
1512 	---------------------------
1513  *
1514  * Nuances of mode 1:
1515  *	For short packets, no ack (+RxPktRdy) is sent automatically
1516  *	(even if AutoClear is ON)
1517  *	For full packets, ack (~RxPktRdy) and next IN token (+ReqPkt) is sent
1518  *	automatically => major problem, as collecting the next packet becomes
1519  *	difficult. Hence mode 1 is not used.
1520  *
1521  * REVISIT
1522  *	All we care about at this driver level is that
1523  *       (a) all URBs terminate with REQPKT cleared and fifo(s) empty;
1524  *       (b) termination conditions are: short RX, or buffer full;
1525  *       (c) fault modes include
1526  *           - iff URB_SHORT_NOT_OK, short RX status is -EREMOTEIO.
1527  *             (and that endpoint's dma queue stops immediately)
1528  *           - overflow (full, PLUS more bytes in the terminal packet)
1529  *
1530  *	So for example, usb-storage sets URB_SHORT_NOT_OK, and would
1531  *	thus be a great candidate for using mode 1 ... for all but the
1532  *	last packet of one URB's transfer.
1533  */
1534 static int musb_rx_dma_inventra_cppi41(struct dma_controller *dma,
1535 				       struct musb_hw_ep *hw_ep,
1536 				       struct musb_qh *qh,
1537 				       struct urb *urb,
1538 				       size_t len)
1539 {
1540 	struct dma_channel *channel = hw_ep->rx_channel;
1541 	void __iomem *epio = hw_ep->regs;
1542 	u16 val;
1543 	int pipe;
1544 	bool done;
1545 
1546 	pipe = urb->pipe;
1547 
1548 	if (usb_pipeisoc(pipe)) {
1549 		struct usb_iso_packet_descriptor *d;
1550 
1551 		d = urb->iso_frame_desc + qh->iso_idx;
1552 		d->actual_length = len;
1553 
1554 		/* even if there was an error, we did the dma
1555 		 * for iso_frame_desc->length
1556 		 */
1557 		if (d->status != -EILSEQ && d->status != -EOVERFLOW)
1558 			d->status = 0;
1559 
1560 		if (++qh->iso_idx >= urb->number_of_packets) {
1561 			done = true;
1562 		} else {
1563 			/* REVISIT: Why ignore return value here? */
1564 			if (musb_dma_cppi41(hw_ep->musb))
1565 				done = musb_rx_dma_iso_cppi41(dma, hw_ep, qh,
1566 							      urb, len);
1567 			done = false;
1568 		}
1569 
1570 	} else  {
1571 		/* done if urb buffer is full or short packet is recd */
1572 		done = (urb->actual_length + len >=
1573 			urb->transfer_buffer_length
1574 			|| channel->actual_len < qh->maxpacket
1575 			|| channel->rx_packet_done);
1576 	}
1577 
1578 	/* send IN token for next packet, without AUTOREQ */
1579 	if (!done) {
1580 		val = musb_readw(epio, MUSB_RXCSR);
1581 		val |= MUSB_RXCSR_H_REQPKT;
1582 		musb_writew(epio, MUSB_RXCSR, MUSB_RXCSR_H_WZC_BITS | val);
1583 	}
1584 
1585 	return done;
1586 }
1587 
1588 /* Disadvantage of using mode 1:
1589  *	It's basically usable only for mass storage class; essentially all
1590  *	other protocols also terminate transfers on short packets.
1591  *
1592  * Details:
1593  *	An extra IN token is sent at the end of the transfer (due to AUTOREQ)
1594  *	If you try to use mode 1 for (transfer_buffer_length - 512), and try
1595  *	to use the extra IN token to grab the last packet using mode 0, then
1596  *	the problem is that you cannot be sure when the device will send the
1597  *	last packet and RxPktRdy set. Sometimes the packet is recd too soon
1598  *	such that it gets lost when RxCSR is re-set at the end of the mode 1
1599  *	transfer, while sometimes it is recd just a little late so that if you
1600  *	try to configure for mode 0 soon after the mode 1 transfer is
1601  *	completed, you will find rxcount 0. Okay, so you might think why not
1602  *	wait for an interrupt when the pkt is recd. Well, you won't get any!
1603  */
1604 static int musb_rx_dma_in_inventra_cppi41(struct dma_controller *dma,
1605 					  struct musb_hw_ep *hw_ep,
1606 					  struct musb_qh *qh,
1607 					  struct urb *urb,
1608 					  size_t len,
1609 					  u8 iso_err)
1610 {
1611 	struct musb *musb = hw_ep->musb;
1612 	void __iomem *epio = hw_ep->regs;
1613 	struct dma_channel *channel = hw_ep->rx_channel;
1614 	u16 rx_count, val;
1615 	int length, pipe, done;
1616 	dma_addr_t buf;
1617 
1618 	rx_count = musb_readw(epio, MUSB_RXCOUNT);
1619 	pipe = urb->pipe;
1620 
1621 	if (usb_pipeisoc(pipe)) {
1622 		int d_status = 0;
1623 		struct usb_iso_packet_descriptor *d;
1624 
1625 		d = urb->iso_frame_desc + qh->iso_idx;
1626 
1627 		if (iso_err) {
1628 			d_status = -EILSEQ;
1629 			urb->error_count++;
1630 		}
1631 		if (rx_count > d->length) {
1632 			if (d_status == 0) {
1633 				d_status = -EOVERFLOW;
1634 				urb->error_count++;
1635 			}
1636 			musb_dbg(musb, "** OVERFLOW %d into %d",
1637 				rx_count, d->length);
1638 
1639 			length = d->length;
1640 		} else
1641 			length = rx_count;
1642 		d->status = d_status;
1643 		buf = urb->transfer_dma + d->offset;
1644 	} else {
1645 		length = rx_count;
1646 		buf = urb->transfer_dma + urb->actual_length;
1647 	}
1648 
1649 	channel->desired_mode = 0;
1650 #ifdef USE_MODE1
1651 	/* because of the issue below, mode 1 will
1652 	 * only rarely behave with correct semantics.
1653 	 */
1654 	if ((urb->transfer_flags & URB_SHORT_NOT_OK)
1655 	    && (urb->transfer_buffer_length - urb->actual_length)
1656 	    > qh->maxpacket)
1657 		channel->desired_mode = 1;
1658 	if (rx_count < hw_ep->max_packet_sz_rx) {
1659 		length = rx_count;
1660 		channel->desired_mode = 0;
1661 	} else {
1662 		length = urb->transfer_buffer_length;
1663 	}
1664 #endif
1665 
1666 	/* See comments above on disadvantages of using mode 1 */
1667 	val = musb_readw(epio, MUSB_RXCSR);
1668 	val &= ~MUSB_RXCSR_H_REQPKT;
1669 
1670 	if (channel->desired_mode == 0)
1671 		val &= ~MUSB_RXCSR_H_AUTOREQ;
1672 	else
1673 		val |= MUSB_RXCSR_H_AUTOREQ;
1674 	val |= MUSB_RXCSR_DMAENAB;
1675 
1676 	/* autoclear shouldn't be set in high bandwidth */
1677 	if (qh->hb_mult == 1)
1678 		val |= MUSB_RXCSR_AUTOCLEAR;
1679 
1680 	musb_writew(epio, MUSB_RXCSR, MUSB_RXCSR_H_WZC_BITS | val);
1681 
1682 	/* REVISIT if when actual_length != 0,
1683 	 * transfer_buffer_length needs to be
1684 	 * adjusted first...
1685 	 */
1686 	done = dma->channel_program(channel, qh->maxpacket,
1687 				   channel->desired_mode,
1688 				   buf, length);
1689 
1690 	if (!done) {
1691 		dma->channel_release(channel);
1692 		hw_ep->rx_channel = NULL;
1693 		channel = NULL;
1694 		val = musb_readw(epio, MUSB_RXCSR);
1695 		val &= ~(MUSB_RXCSR_DMAENAB
1696 			 | MUSB_RXCSR_H_AUTOREQ
1697 			 | MUSB_RXCSR_AUTOCLEAR);
1698 		musb_writew(epio, MUSB_RXCSR, val);
1699 	}
1700 
1701 	return done;
1702 }
1703 #else
1704 static inline int musb_rx_dma_inventra_cppi41(struct dma_controller *dma,
1705 					      struct musb_hw_ep *hw_ep,
1706 					      struct musb_qh *qh,
1707 					      struct urb *urb,
1708 					      size_t len)
1709 {
1710 	return false;
1711 }
1712 
1713 static inline int musb_rx_dma_in_inventra_cppi41(struct dma_controller *dma,
1714 						 struct musb_hw_ep *hw_ep,
1715 						 struct musb_qh *qh,
1716 						 struct urb *urb,
1717 						 size_t len,
1718 						 u8 iso_err)
1719 {
1720 	return false;
1721 }
1722 #endif
1723 
1724 /*
1725  * Service an RX interrupt for the given IN endpoint; docs cover bulk, iso,
1726  * and high-bandwidth IN transfer cases.
1727  */
1728 void musb_host_rx(struct musb *musb, u8 epnum)
1729 {
1730 	struct urb		*urb;
1731 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1732 	struct dma_controller	*c = musb->dma_controller;
1733 	void __iomem		*epio = hw_ep->regs;
1734 	struct musb_qh		*qh = hw_ep->in_qh;
1735 	size_t			xfer_len;
1736 	void __iomem		*mbase = musb->mregs;
1737 	u16			rx_csr, val;
1738 	bool			iso_err = false;
1739 	bool			done = false;
1740 	u32			status;
1741 	struct dma_channel	*dma;
1742 	unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
1743 
1744 	musb_ep_select(mbase, epnum);
1745 
1746 	urb = next_urb(qh);
1747 	dma = is_dma_capable() ? hw_ep->rx_channel : NULL;
1748 	status = 0;
1749 	xfer_len = 0;
1750 
1751 	rx_csr = musb_readw(epio, MUSB_RXCSR);
1752 	val = rx_csr;
1753 
1754 	if (unlikely(!urb)) {
1755 		/* REVISIT -- THIS SHOULD NEVER HAPPEN ... but, at least
1756 		 * usbtest #11 (unlinks) triggers it regularly, sometimes
1757 		 * with fifo full.  (Only with DMA??)
1758 		 */
1759 		musb_dbg(musb, "BOGUS RX%d ready, csr %04x, count %d",
1760 			epnum, val, musb_readw(epio, MUSB_RXCOUNT));
1761 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1762 		return;
1763 	}
1764 
1765 	trace_musb_urb_rx(musb, urb);
1766 
1767 	/* check for errors, concurrent stall & unlink is not really
1768 	 * handled yet! */
1769 	if (rx_csr & MUSB_RXCSR_H_RXSTALL) {
1770 		musb_dbg(musb, "RX end %d STALL", epnum);
1771 
1772 		/* stall; record URB status */
1773 		status = -EPIPE;
1774 
1775 	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
1776 		dev_err(musb->controller, "ep%d RX three-strikes error", epnum);
1777 
1778 		/*
1779 		 * The three-strikes error could only happen when the USB
1780 		 * device is not accessible, for example detached or powered
1781 		 * off. So return the fatal error -ESHUTDOWN so hopefully the
1782 		 * USB device drivers won't immediately resubmit the same URB.
1783 		 */
1784 		status = -ESHUTDOWN;
1785 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1786 
1787 		rx_csr &= ~MUSB_RXCSR_H_ERROR;
1788 		musb_writew(epio, MUSB_RXCSR, rx_csr);
1789 
1790 	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
1791 
1792 		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
1793 			musb_dbg(musb, "RX end %d NAK timeout", epnum);
1794 
1795 			/* NOTE: NAKing is *NOT* an error, so we want to
1796 			 * continue.  Except ... if there's a request for
1797 			 * another QH, use that instead of starving it.
1798 			 *
1799 			 * Devices like Ethernet and serial adapters keep
1800 			 * reads posted at all times, which will starve
1801 			 * other devices without this logic.
1802 			 */
1803 			if (usb_pipebulk(urb->pipe)
1804 					&& qh->mux == 1
1805 					&& !list_is_singular(&musb->in_bulk)) {
1806 				musb_bulk_nak_timeout(musb, hw_ep, 1);
1807 				return;
1808 			}
1809 			musb_ep_select(mbase, epnum);
1810 			rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1811 			rx_csr &= ~MUSB_RXCSR_DATAERROR;
1812 			musb_writew(epio, MUSB_RXCSR, rx_csr);
1813 
1814 			goto finish;
1815 		} else {
1816 			musb_dbg(musb, "RX end %d ISO data error", epnum);
1817 			/* packet error reported later */
1818 			iso_err = true;
1819 		}
1820 	} else if (rx_csr & MUSB_RXCSR_INCOMPRX) {
1821 		musb_dbg(musb, "end %d high bandwidth incomplete ISO packet RX",
1822 				epnum);
1823 		status = -EPROTO;
1824 	}
1825 
1826 	/* faults abort the transfer */
1827 	if (status) {
1828 		/* clean up dma and collect transfer count */
1829 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1830 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1831 			musb->dma_controller->channel_abort(dma);
1832 			xfer_len = dma->actual_len;
1833 		}
1834 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1835 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1836 		done = true;
1837 		goto finish;
1838 	}
1839 
1840 	if (unlikely(dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY)) {
1841 		/* SHOULD NEVER HAPPEN ... but at least DaVinci has done it */
1842 		ERR("RX%d dma busy, csr %04x\n", epnum, rx_csr);
1843 		goto finish;
1844 	}
1845 
1846 	/* thorough shutdown for now ... given more precise fault handling
1847 	 * and better queueing support, we might keep a DMA pipeline going
1848 	 * while processing this irq for earlier completions.
1849 	 */
1850 
1851 	/* FIXME this is _way_ too much in-line logic for Mentor DMA */
1852 	if (!musb_dma_inventra(musb) && !musb_dma_ux500(musb) &&
1853 	    (rx_csr & MUSB_RXCSR_H_REQPKT)) {
1854 		/* REVISIT this happened for a while on some short reads...
1855 		 * the cleanup still needs investigation... looks bad...
1856 		 * and also duplicates dma cleanup code above ... plus,
1857 		 * shouldn't this be the "half full" double buffer case?
1858 		 */
1859 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1860 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1861 			musb->dma_controller->channel_abort(dma);
1862 			xfer_len = dma->actual_len;
1863 			done = true;
1864 		}
1865 
1866 		musb_dbg(musb, "RXCSR%d %04x, reqpkt, len %zu%s", epnum, rx_csr,
1867 				xfer_len, dma ? ", dma" : "");
1868 		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
1869 
1870 		musb_ep_select(mbase, epnum);
1871 		musb_writew(epio, MUSB_RXCSR,
1872 				MUSB_RXCSR_H_WZC_BITS | rx_csr);
1873 	}
1874 
1875 	if (dma && (rx_csr & MUSB_RXCSR_DMAENAB)) {
1876 		xfer_len = dma->actual_len;
1877 
1878 		val &= ~(MUSB_RXCSR_DMAENAB
1879 			| MUSB_RXCSR_H_AUTOREQ
1880 			| MUSB_RXCSR_AUTOCLEAR
1881 			| MUSB_RXCSR_RXPKTRDY);
1882 		musb_writew(hw_ep->regs, MUSB_RXCSR, val);
1883 
1884 		if (musb_dma_inventra(musb) || musb_dma_ux500(musb) ||
1885 		    musb_dma_cppi41(musb)) {
1886 			    done = musb_rx_dma_inventra_cppi41(c, hw_ep, qh, urb, xfer_len);
1887 			    musb_dbg(hw_ep->musb,
1888 				    "ep %d dma %s, rxcsr %04x, rxcount %d",
1889 				    epnum, done ? "off" : "reset",
1890 				    musb_readw(epio, MUSB_RXCSR),
1891 				    musb_readw(epio, MUSB_RXCOUNT));
1892 		} else {
1893 			done = true;
1894 		}
1895 
1896 	} else if (urb->status == -EINPROGRESS) {
1897 		/* if no errors, be sure a packet is ready for unloading */
1898 		if (unlikely(!(rx_csr & MUSB_RXCSR_RXPKTRDY))) {
1899 			status = -EPROTO;
1900 			ERR("Rx interrupt with no errors or packet!\n");
1901 
1902 			/* FIXME this is another "SHOULD NEVER HAPPEN" */
1903 
1904 /* SCRUB (RX) */
1905 			/* do the proper sequence to abort the transfer */
1906 			musb_ep_select(mbase, epnum);
1907 			val &= ~MUSB_RXCSR_H_REQPKT;
1908 			musb_writew(epio, MUSB_RXCSR, val);
1909 			goto finish;
1910 		}
1911 
1912 		/* we are expecting IN packets */
1913 		if ((musb_dma_inventra(musb) || musb_dma_ux500(musb) ||
1914 		    musb_dma_cppi41(musb)) && dma) {
1915 			musb_dbg(hw_ep->musb,
1916 				"RX%d count %d, buffer 0x%llx len %d/%d",
1917 				epnum, musb_readw(epio, MUSB_RXCOUNT),
1918 				(unsigned long long) urb->transfer_dma
1919 				+ urb->actual_length,
1920 				qh->offset,
1921 				urb->transfer_buffer_length);
1922 
1923 			if (musb_rx_dma_in_inventra_cppi41(c, hw_ep, qh, urb,
1924 							   xfer_len, iso_err))
1925 				goto finish;
1926 			else
1927 				dev_err(musb->controller, "error: rx_dma failed\n");
1928 		}
1929 
1930 		if (!dma) {
1931 			unsigned int received_len;
1932 
1933 			/* Unmap the buffer so that CPU can use it */
1934 			usb_hcd_unmap_urb_for_dma(musb->hcd, urb);
1935 
1936 			/*
1937 			 * We need to map sg if the transfer_buffer is
1938 			 * NULL.
1939 			 */
1940 			if (!urb->transfer_buffer) {
1941 				qh->use_sg = true;
1942 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
1943 						sg_flags);
1944 			}
1945 
1946 			if (qh->use_sg) {
1947 				if (!sg_miter_next(&qh->sg_miter)) {
1948 					dev_err(musb->controller, "error: sg list empty\n");
1949 					sg_miter_stop(&qh->sg_miter);
1950 					status = -EINVAL;
1951 					done = true;
1952 					goto finish;
1953 				}
1954 				urb->transfer_buffer = qh->sg_miter.addr;
1955 				received_len = urb->actual_length;
1956 				qh->offset = 0x0;
1957 				done = musb_host_packet_rx(musb, urb, epnum,
1958 						iso_err);
1959 				/* Calculate the number of bytes received */
1960 				received_len = urb->actual_length -
1961 					received_len;
1962 				qh->sg_miter.consumed = received_len;
1963 				sg_miter_stop(&qh->sg_miter);
1964 			} else {
1965 				done = musb_host_packet_rx(musb, urb,
1966 						epnum, iso_err);
1967 			}
1968 			musb_dbg(musb, "read %spacket", done ? "last " : "");
1969 		}
1970 	}
1971 
1972 finish:
1973 	urb->actual_length += xfer_len;
1974 	qh->offset += xfer_len;
1975 	if (done) {
1976 		if (qh->use_sg) {
1977 			qh->use_sg = false;
1978 			urb->transfer_buffer = NULL;
1979 		}
1980 
1981 		if (urb->status == -EINPROGRESS)
1982 			urb->status = status;
1983 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
1984 	}
1985 }
1986 
1987 /* schedule nodes correspond to peripheral endpoints, like an OHCI QH.
1988  * the software schedule associates multiple such nodes with a given
1989  * host side hardware endpoint + direction; scheduling may activate
1990  * that hardware endpoint.
1991  */
1992 static int musb_schedule(
1993 	struct musb		*musb,
1994 	struct musb_qh		*qh,
1995 	int			is_in)
1996 {
1997 	int			idle = 0;
1998 	int			best_diff;
1999 	int			best_end, epnum;
2000 	struct musb_hw_ep	*hw_ep = NULL;
2001 	struct list_head	*head = NULL;
2002 	u8			toggle;
2003 	u8			txtype;
2004 	struct urb		*urb = next_urb(qh);
2005 
2006 	/* use fixed hardware for control and bulk */
2007 	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
2008 		head = &musb->control;
2009 		hw_ep = musb->control_ep;
2010 		goto success;
2011 	}
2012 
2013 	/* else, periodic transfers get muxed to other endpoints */
2014 
2015 	/*
2016 	 * We know this qh hasn't been scheduled, so all we need to do
2017 	 * is choose which hardware endpoint to put it on ...
2018 	 *
2019 	 * REVISIT what we really want here is a regular schedule tree
2020 	 * like e.g. OHCI uses.
2021 	 */
2022 	best_diff = 4096;
2023 	best_end = -1;
2024 
2025 	for (epnum = 1, hw_ep = musb->endpoints + 1;
2026 			epnum < musb->nr_endpoints;
2027 			epnum++, hw_ep++) {
2028 		int	diff;
2029 
2030 		if (musb_ep_get_qh(hw_ep, is_in) != NULL)
2031 			continue;
2032 
2033 		if (hw_ep == musb->bulk_ep)
2034 			continue;
2035 
2036 		if (is_in)
2037 			diff = hw_ep->max_packet_sz_rx;
2038 		else
2039 			diff = hw_ep->max_packet_sz_tx;
2040 		diff -= (qh->maxpacket * qh->hb_mult);
2041 
2042 		if (diff >= 0 && best_diff > diff) {
2043 
2044 			/*
2045 			 * Mentor controller has a bug in that if we schedule
2046 			 * a BULK Tx transfer on an endpoint that had earlier
2047 			 * handled ISOC then the BULK transfer has to start on
2048 			 * a zero toggle.  If the BULK transfer starts on a 1
2049 			 * toggle then this transfer will fail as the mentor
2050 			 * controller starts the Bulk transfer on a 0 toggle
2051 			 * irrespective of the programming of the toggle bits
2052 			 * in the TXCSR register.  Check for this condition
2053 			 * while allocating the EP for a Tx Bulk transfer.  If
2054 			 * so skip this EP.
2055 			 */
2056 			hw_ep = musb->endpoints + epnum;
2057 			toggle = usb_gettoggle(urb->dev, qh->epnum, !is_in);
2058 			txtype = (musb_readb(hw_ep->regs, MUSB_TXTYPE)
2059 					>> 4) & 0x3;
2060 			if (!is_in && (qh->type == USB_ENDPOINT_XFER_BULK) &&
2061 				toggle && (txtype == USB_ENDPOINT_XFER_ISOC))
2062 				continue;
2063 
2064 			best_diff = diff;
2065 			best_end = epnum;
2066 		}
2067 	}
2068 	/* use bulk reserved ep1 if no other ep is free */
2069 	if (best_end < 0 && qh->type == USB_ENDPOINT_XFER_BULK) {
2070 		hw_ep = musb->bulk_ep;
2071 		if (is_in)
2072 			head = &musb->in_bulk;
2073 		else
2074 			head = &musb->out_bulk;
2075 
2076 		/* Enable bulk RX/TX NAK timeout scheme when bulk requests are
2077 		 * multiplexed. This scheme does not work in high speed to full
2078 		 * speed scenario as NAK interrupts are not coming from a
2079 		 * full speed device connected to a high speed device.
2080 		 * NAK timeout interval is 8 (128 uframe or 16ms) for HS and
2081 		 * 4 (8 frame or 8ms) for FS device.
2082 		 */
2083 		if (qh->dev)
2084 			qh->intv_reg =
2085 				(USB_SPEED_HIGH == qh->dev->speed) ? 8 : 4;
2086 		goto success;
2087 	} else if (best_end < 0) {
2088 		dev_err(musb->controller,
2089 				"%s hwep alloc failed for %dx%d\n",
2090 				musb_ep_xfertype_string(qh->type),
2091 				qh->hb_mult, qh->maxpacket);
2092 		return -ENOSPC;
2093 	}
2094 
2095 	idle = 1;
2096 	qh->mux = 0;
2097 	hw_ep = musb->endpoints + best_end;
2098 	musb_dbg(musb, "qh %p periodic slot %d", qh, best_end);
2099 success:
2100 	if (head) {
2101 		idle = list_empty(head);
2102 		list_add_tail(&qh->ring, head);
2103 		qh->mux = 1;
2104 	}
2105 	qh->hw_ep = hw_ep;
2106 	qh->hep->hcpriv = qh;
2107 	if (idle)
2108 		musb_start_urb(musb, is_in, qh);
2109 	return 0;
2110 }
2111 
2112 static int musb_urb_enqueue(
2113 	struct usb_hcd			*hcd,
2114 	struct urb			*urb,
2115 	gfp_t				mem_flags)
2116 {
2117 	unsigned long			flags;
2118 	struct musb			*musb = hcd_to_musb(hcd);
2119 	struct usb_host_endpoint	*hep = urb->ep;
2120 	struct musb_qh			*qh;
2121 	struct usb_endpoint_descriptor	*epd = &hep->desc;
2122 	int				ret;
2123 	unsigned			type_reg;
2124 	unsigned			interval;
2125 
2126 	/* host role must be active */
2127 	if (!is_host_active(musb) || !musb->is_active)
2128 		return -ENODEV;
2129 
2130 	trace_musb_urb_enq(musb, urb);
2131 
2132 	spin_lock_irqsave(&musb->lock, flags);
2133 	ret = usb_hcd_link_urb_to_ep(hcd, urb);
2134 	qh = ret ? NULL : hep->hcpriv;
2135 	if (qh)
2136 		urb->hcpriv = qh;
2137 	spin_unlock_irqrestore(&musb->lock, flags);
2138 
2139 	/* DMA mapping was already done, if needed, and this urb is on
2140 	 * hep->urb_list now ... so we're done, unless hep wasn't yet
2141 	 * scheduled onto a live qh.
2142 	 *
2143 	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets
2144 	 * disabled, testing for empty qh->ring and avoiding qh setup costs
2145 	 * except for the first urb queued after a config change.
2146 	 */
2147 	if (qh || ret)
2148 		return ret;
2149 
2150 	/* Allocate and initialize qh, minimizing the work done each time
2151 	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.
2152 	 *
2153 	 * REVISIT consider a dedicated qh kmem_cache, so it's harder
2154 	 * for bugs in other kernel code to break this driver...
2155 	 */
2156 	qh = kzalloc(sizeof *qh, mem_flags);
2157 	if (!qh) {
2158 		spin_lock_irqsave(&musb->lock, flags);
2159 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2160 		spin_unlock_irqrestore(&musb->lock, flags);
2161 		return -ENOMEM;
2162 	}
2163 
2164 	qh->hep = hep;
2165 	qh->dev = urb->dev;
2166 	INIT_LIST_HEAD(&qh->ring);
2167 	qh->is_ready = 1;
2168 
2169 	qh->maxpacket = usb_endpoint_maxp(epd);
2170 	qh->type = usb_endpoint_type(epd);
2171 
2172 	/* Bits 11 & 12 of wMaxPacketSize encode high bandwidth multiplier.
2173 	 * Some musb cores don't support high bandwidth ISO transfers; and
2174 	 * we don't (yet!) support high bandwidth interrupt transfers.
2175 	 */
2176 	qh->hb_mult = usb_endpoint_maxp_mult(epd);
2177 	if (qh->hb_mult > 1) {
2178 		int ok = (qh->type == USB_ENDPOINT_XFER_ISOC);
2179 
2180 		if (ok)
2181 			ok = (usb_pipein(urb->pipe) && musb->hb_iso_rx)
2182 				|| (usb_pipeout(urb->pipe) && musb->hb_iso_tx);
2183 		if (!ok) {
2184 			dev_err(musb->controller,
2185 				"high bandwidth %s (%dx%d) not supported\n",
2186 				musb_ep_xfertype_string(qh->type),
2187 				qh->hb_mult, qh->maxpacket & 0x7ff);
2188 			ret = -EMSGSIZE;
2189 			goto done;
2190 		}
2191 		qh->maxpacket &= 0x7ff;
2192 	}
2193 
2194 	qh->epnum = usb_endpoint_num(epd);
2195 
2196 	/* NOTE: urb->dev->devnum is wrong during SET_ADDRESS */
2197 	qh->addr_reg = (u8) usb_pipedevice(urb->pipe);
2198 
2199 	/* precompute rxtype/txtype/type0 register */
2200 	type_reg = (qh->type << 4) | qh->epnum;
2201 	switch (urb->dev->speed) {
2202 	case USB_SPEED_LOW:
2203 		type_reg |= 0xc0;
2204 		break;
2205 	case USB_SPEED_FULL:
2206 		type_reg |= 0x80;
2207 		break;
2208 	default:
2209 		type_reg |= 0x40;
2210 	}
2211 	qh->type_reg = type_reg;
2212 
2213 	/* Precompute RXINTERVAL/TXINTERVAL register */
2214 	switch (qh->type) {
2215 	case USB_ENDPOINT_XFER_INT:
2216 		/*
2217 		 * Full/low speeds use the  linear encoding,
2218 		 * high speed uses the logarithmic encoding.
2219 		 */
2220 		if (urb->dev->speed <= USB_SPEED_FULL) {
2221 			interval = max_t(u8, epd->bInterval, 1);
2222 			break;
2223 		}
2224 		fallthrough;
2225 	case USB_ENDPOINT_XFER_ISOC:
2226 		/* ISO always uses logarithmic encoding */
2227 		interval = min_t(u8, epd->bInterval, 16);
2228 		break;
2229 	default:
2230 		/* REVISIT we actually want to use NAK limits, hinting to the
2231 		 * transfer scheduling logic to try some other qh, e.g. try
2232 		 * for 2 msec first:
2233 		 *
2234 		 * interval = (USB_SPEED_HIGH == urb->dev->speed) ? 16 : 2;
2235 		 *
2236 		 * The downside of disabling this is that transfer scheduling
2237 		 * gets VERY unfair for nonperiodic transfers; a misbehaving
2238 		 * peripheral could make that hurt.  That's perfectly normal
2239 		 * for reads from network or serial adapters ... so we have
2240 		 * partial NAKlimit support for bulk RX.
2241 		 *
2242 		 * The upside of disabling it is simpler transfer scheduling.
2243 		 */
2244 		interval = 0;
2245 	}
2246 	qh->intv_reg = interval;
2247 
2248 	/* precompute addressing for external hub/tt ports */
2249 	if (musb->is_multipoint) {
2250 		struct usb_device	*parent = urb->dev->parent;
2251 
2252 		if (parent != hcd->self.root_hub) {
2253 			qh->h_addr_reg = (u8) parent->devnum;
2254 
2255 			/* set up tt info if needed */
2256 			if (urb->dev->tt) {
2257 				qh->h_port_reg = (u8) urb->dev->ttport;
2258 				if (urb->dev->tt->hub)
2259 					qh->h_addr_reg =
2260 						(u8) urb->dev->tt->hub->devnum;
2261 				if (urb->dev->tt->multi)
2262 					qh->h_addr_reg |= 0x80;
2263 			}
2264 		}
2265 	}
2266 
2267 	/* invariant: hep->hcpriv is null OR the qh that's already scheduled.
2268 	 * until we get real dma queues (with an entry for each urb/buffer),
2269 	 * we only have work to do in the former case.
2270 	 */
2271 	spin_lock_irqsave(&musb->lock, flags);
2272 	if (hep->hcpriv || !next_urb(qh)) {
2273 		/* some concurrent activity submitted another urb to hep...
2274 		 * odd, rare, error prone, but legal.
2275 		 */
2276 		kfree(qh);
2277 		qh = NULL;
2278 		ret = 0;
2279 	} else
2280 		ret = musb_schedule(musb, qh,
2281 				epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK);
2282 
2283 	if (ret == 0) {
2284 		urb->hcpriv = qh;
2285 		/* FIXME set urb->start_frame for iso/intr, it's tested in
2286 		 * musb_start_urb(), but otherwise only konicawc cares ...
2287 		 */
2288 	}
2289 	spin_unlock_irqrestore(&musb->lock, flags);
2290 
2291 done:
2292 	if (ret != 0) {
2293 		spin_lock_irqsave(&musb->lock, flags);
2294 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2295 		spin_unlock_irqrestore(&musb->lock, flags);
2296 		kfree(qh);
2297 	}
2298 	return ret;
2299 }
2300 
2301 
2302 /*
2303  * abort a transfer that's at the head of a hardware queue.
2304  * called with controller locked, irqs blocked
2305  * that hardware queue advances to the next transfer, unless prevented
2306  */
2307 static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
2308 {
2309 	struct musb_hw_ep	*ep = qh->hw_ep;
2310 	struct musb		*musb = ep->musb;
2311 	void __iomem		*epio = ep->regs;
2312 	unsigned		hw_end = ep->epnum;
2313 	void __iomem		*regs = ep->musb->mregs;
2314 	int			is_in = usb_pipein(urb->pipe);
2315 	int			status = 0;
2316 	u16			csr;
2317 	struct dma_channel	*dma = NULL;
2318 
2319 	musb_ep_select(regs, hw_end);
2320 
2321 	if (is_dma_capable()) {
2322 		dma = is_in ? ep->rx_channel : ep->tx_channel;
2323 		if (dma) {
2324 			status = ep->musb->dma_controller->channel_abort(dma);
2325 			musb_dbg(musb, "abort %cX%d DMA for urb %p --> %d",
2326 				is_in ? 'R' : 'T', ep->epnum,
2327 				urb, status);
2328 			urb->actual_length += dma->actual_len;
2329 		}
2330 	}
2331 
2332 	/* turn off DMA requests, discard state, stop polling ... */
2333 	if (ep->epnum && is_in) {
2334 		/* giveback saves bulk toggle */
2335 		csr = musb_h_flush_rxfifo(ep, 0);
2336 
2337 		/* clear the endpoint's irq status here to avoid bogus irqs */
2338 		if (is_dma_capable() && dma)
2339 			musb_platform_clear_ep_rxintr(musb, ep->epnum);
2340 	} else if (ep->epnum) {
2341 		musb_h_tx_flush_fifo(ep);
2342 		csr = musb_readw(epio, MUSB_TXCSR);
2343 		csr &= ~(MUSB_TXCSR_AUTOSET
2344 			| MUSB_TXCSR_DMAENAB
2345 			| MUSB_TXCSR_H_RXSTALL
2346 			| MUSB_TXCSR_H_NAKTIMEOUT
2347 			| MUSB_TXCSR_H_ERROR
2348 			| MUSB_TXCSR_TXPKTRDY);
2349 		musb_writew(epio, MUSB_TXCSR, csr);
2350 		/* REVISIT may need to clear FLUSHFIFO ... */
2351 		musb_writew(epio, MUSB_TXCSR, csr);
2352 		/* flush cpu writebuffer */
2353 		csr = musb_readw(epio, MUSB_TXCSR);
2354 	} else  {
2355 		musb_h_ep0_flush_fifo(ep);
2356 	}
2357 	if (status == 0)
2358 		musb_advance_schedule(ep->musb, urb, ep, is_in);
2359 	return status;
2360 }
2361 
2362 static int musb_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
2363 {
2364 	struct musb		*musb = hcd_to_musb(hcd);
2365 	struct musb_qh		*qh;
2366 	unsigned long		flags;
2367 	int			is_in  = usb_pipein(urb->pipe);
2368 	int			ret;
2369 
2370 	trace_musb_urb_deq(musb, urb);
2371 
2372 	spin_lock_irqsave(&musb->lock, flags);
2373 	ret = usb_hcd_check_unlink_urb(hcd, urb, status);
2374 	if (ret)
2375 		goto done;
2376 
2377 	qh = urb->hcpriv;
2378 	if (!qh)
2379 		goto done;
2380 
2381 	/*
2382 	 * Any URB not actively programmed into endpoint hardware can be
2383 	 * immediately given back; that's any URB not at the head of an
2384 	 * endpoint queue, unless someday we get real DMA queues.  And even
2385 	 * if it's at the head, it might not be known to the hardware...
2386 	 *
2387 	 * Otherwise abort current transfer, pending DMA, etc.; urb->status
2388 	 * has already been updated.  This is a synchronous abort; it'd be
2389 	 * OK to hold off until after some IRQ, though.
2390 	 *
2391 	 * NOTE: qh is invalid unless !list_empty(&hep->urb_list)
2392 	 */
2393 	if (!qh->is_ready
2394 			|| urb->urb_list.prev != &qh->hep->urb_list
2395 			|| musb_ep_get_qh(qh->hw_ep, is_in) != qh) {
2396 		int	ready = qh->is_ready;
2397 
2398 		qh->is_ready = 0;
2399 		musb_giveback(musb, urb, 0);
2400 		qh->is_ready = ready;
2401 
2402 		/* If nothing else (usually musb_giveback) is using it
2403 		 * and its URB list has emptied, recycle this qh.
2404 		 */
2405 		if (ready && list_empty(&qh->hep->urb_list)) {
2406 			musb_ep_set_qh(qh->hw_ep, is_in, NULL);
2407 			qh->hep->hcpriv = NULL;
2408 			list_del(&qh->ring);
2409 			kfree(qh);
2410 		}
2411 	} else
2412 		ret = musb_cleanup_urb(urb, qh);
2413 done:
2414 	spin_unlock_irqrestore(&musb->lock, flags);
2415 	return ret;
2416 }
2417 
2418 /* disable an endpoint */
2419 static void
2420 musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
2421 {
2422 	u8			is_in = hep->desc.bEndpointAddress & USB_DIR_IN;
2423 	unsigned long		flags;
2424 	struct musb		*musb = hcd_to_musb(hcd);
2425 	struct musb_qh		*qh;
2426 	struct urb		*urb;
2427 
2428 	spin_lock_irqsave(&musb->lock, flags);
2429 
2430 	qh = hep->hcpriv;
2431 	if (qh == NULL)
2432 		goto exit;
2433 
2434 	/* NOTE: qh is invalid unless !list_empty(&hep->urb_list) */
2435 
2436 	/* Kick the first URB off the hardware, if needed */
2437 	qh->is_ready = 0;
2438 	if (musb_ep_get_qh(qh->hw_ep, is_in) == qh) {
2439 		urb = next_urb(qh);
2440 
2441 		/* make software (then hardware) stop ASAP */
2442 		if (!urb->unlinked)
2443 			urb->status = -ESHUTDOWN;
2444 
2445 		/* cleanup */
2446 		musb_cleanup_urb(urb, qh);
2447 
2448 		/* Then nuke all the others ... and advance the
2449 		 * queue on hw_ep (e.g. bulk ring) when we're done.
2450 		 */
2451 		while (!list_empty(&hep->urb_list)) {
2452 			urb = next_urb(qh);
2453 			urb->status = -ESHUTDOWN;
2454 			musb_advance_schedule(musb, urb, qh->hw_ep, is_in);
2455 		}
2456 	} else {
2457 		/* Just empty the queue; the hardware is busy with
2458 		 * other transfers, and since !qh->is_ready nothing
2459 		 * will activate any of these as it advances.
2460 		 */
2461 		while (!list_empty(&hep->urb_list))
2462 			musb_giveback(musb, next_urb(qh), -ESHUTDOWN);
2463 
2464 		hep->hcpriv = NULL;
2465 		list_del(&qh->ring);
2466 		kfree(qh);
2467 	}
2468 exit:
2469 	spin_unlock_irqrestore(&musb->lock, flags);
2470 }
2471 
2472 static int musb_h_get_frame_number(struct usb_hcd *hcd)
2473 {
2474 	struct musb	*musb = hcd_to_musb(hcd);
2475 
2476 	return musb_readw(musb->mregs, MUSB_FRAME);
2477 }
2478 
2479 static int musb_h_start(struct usb_hcd *hcd)
2480 {
2481 	struct musb	*musb = hcd_to_musb(hcd);
2482 
2483 	/* NOTE: musb_start() is called when the hub driver turns
2484 	 * on port power, or when (OTG) peripheral starts.
2485 	 */
2486 	hcd->state = HC_STATE_RUNNING;
2487 	musb->port1_status = 0;
2488 	return 0;
2489 }
2490 
2491 static void musb_h_stop(struct usb_hcd *hcd)
2492 {
2493 	musb_stop(hcd_to_musb(hcd));
2494 	hcd->state = HC_STATE_HALT;
2495 }
2496 
2497 static int musb_bus_suspend(struct usb_hcd *hcd)
2498 {
2499 	struct musb	*musb = hcd_to_musb(hcd);
2500 	u8		devctl;
2501 	int		ret;
2502 
2503 	ret = musb_port_suspend(musb, true);
2504 	if (ret)
2505 		return ret;
2506 
2507 	if (!is_host_active(musb))
2508 		return 0;
2509 
2510 	switch (musb_get_state(musb)) {
2511 	case OTG_STATE_A_SUSPEND:
2512 		return 0;
2513 	case OTG_STATE_A_WAIT_VRISE:
2514 		/* ID could be grounded even if there's no device
2515 		 * on the other end of the cable.  NOTE that the
2516 		 * A_WAIT_VRISE timers are messy with MUSB...
2517 		 */
2518 		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2519 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2520 			musb_set_state(musb, OTG_STATE_A_WAIT_BCON);
2521 		break;
2522 	default:
2523 		break;
2524 	}
2525 
2526 	if (musb->is_active) {
2527 		WARNING("trying to suspend as %s while active\n",
2528 			musb_otg_state_string(musb));
2529 		return -EBUSY;
2530 	} else
2531 		return 0;
2532 }
2533 
2534 static int musb_bus_resume(struct usb_hcd *hcd)
2535 {
2536 	struct musb *musb = hcd_to_musb(hcd);
2537 
2538 	if (musb->config &&
2539 	    musb->config->host_port_deassert_reset_at_resume)
2540 		musb_port_reset(musb, false);
2541 
2542 	return 0;
2543 }
2544 
2545 #ifndef CONFIG_MUSB_PIO_ONLY
2546 
2547 #define MUSB_USB_DMA_ALIGN 4
2548 
2549 struct musb_temp_buffer {
2550 	void *kmalloc_ptr;
2551 	void *old_xfer_buffer;
2552 	u8 data[];
2553 };
2554 
2555 static void musb_free_temp_buffer(struct urb *urb)
2556 {
2557 	enum dma_data_direction dir;
2558 	struct musb_temp_buffer *temp;
2559 	size_t length;
2560 
2561 	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
2562 		return;
2563 
2564 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2565 
2566 	temp = container_of(urb->transfer_buffer, struct musb_temp_buffer,
2567 			    data);
2568 
2569 	if (dir == DMA_FROM_DEVICE) {
2570 		if (usb_pipeisoc(urb->pipe))
2571 			length = urb->transfer_buffer_length;
2572 		else
2573 			length = urb->actual_length;
2574 
2575 		memcpy(temp->old_xfer_buffer, temp->data, length);
2576 	}
2577 	urb->transfer_buffer = temp->old_xfer_buffer;
2578 	kfree(temp->kmalloc_ptr);
2579 
2580 	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
2581 }
2582 
2583 static int musb_alloc_temp_buffer(struct urb *urb, gfp_t mem_flags)
2584 {
2585 	enum dma_data_direction dir;
2586 	struct musb_temp_buffer *temp;
2587 	void *kmalloc_ptr;
2588 	size_t kmalloc_size;
2589 
2590 	if (urb->num_sgs || urb->sg ||
2591 	    urb->transfer_buffer_length == 0 ||
2592 	    !((uintptr_t)urb->transfer_buffer & (MUSB_USB_DMA_ALIGN - 1)))
2593 		return 0;
2594 
2595 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2596 
2597 	/* Allocate a buffer with enough padding for alignment */
2598 	kmalloc_size = urb->transfer_buffer_length +
2599 		sizeof(struct musb_temp_buffer) + MUSB_USB_DMA_ALIGN - 1;
2600 
2601 	kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
2602 	if (!kmalloc_ptr)
2603 		return -ENOMEM;
2604 
2605 	/* Position our struct temp_buffer such that data is aligned */
2606 	temp = PTR_ALIGN(kmalloc_ptr, MUSB_USB_DMA_ALIGN);
2607 
2608 
2609 	temp->kmalloc_ptr = kmalloc_ptr;
2610 	temp->old_xfer_buffer = urb->transfer_buffer;
2611 	if (dir == DMA_TO_DEVICE)
2612 		memcpy(temp->data, urb->transfer_buffer,
2613 		       urb->transfer_buffer_length);
2614 	urb->transfer_buffer = temp->data;
2615 
2616 	urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
2617 
2618 	return 0;
2619 }
2620 
2621 static int musb_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
2622 				      gfp_t mem_flags)
2623 {
2624 	struct musb	*musb = hcd_to_musb(hcd);
2625 	int ret;
2626 
2627 	/*
2628 	 * The DMA engine in RTL1.8 and above cannot handle
2629 	 * DMA addresses that are not aligned to a 4 byte boundary.
2630 	 * For such engine implemented (un)map_urb_for_dma hooks.
2631 	 * Do not use these hooks for RTL<1.8
2632 	 */
2633 	if (musb->hwvers < MUSB_HWVERS_1800)
2634 		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
2635 
2636 	ret = musb_alloc_temp_buffer(urb, mem_flags);
2637 	if (ret)
2638 		return ret;
2639 
2640 	ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
2641 	if (ret)
2642 		musb_free_temp_buffer(urb);
2643 
2644 	return ret;
2645 }
2646 
2647 static void musb_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
2648 {
2649 	struct musb	*musb = hcd_to_musb(hcd);
2650 
2651 	usb_hcd_unmap_urb_for_dma(hcd, urb);
2652 
2653 	/* Do not use this hook for RTL<1.8 (see description above) */
2654 	if (musb->hwvers < MUSB_HWVERS_1800)
2655 		return;
2656 
2657 	musb_free_temp_buffer(urb);
2658 }
2659 #endif /* !CONFIG_MUSB_PIO_ONLY */
2660 
2661 static const struct hc_driver musb_hc_driver = {
2662 	.description		= "musb-hcd",
2663 	.product_desc		= "MUSB HDRC host driver",
2664 	.hcd_priv_size		= sizeof(struct musb *),
2665 	.flags			= HCD_USB2 | HCD_DMA | HCD_MEMORY,
2666 
2667 	/* not using irq handler or reset hooks from usbcore, since
2668 	 * those must be shared with peripheral code for OTG configs
2669 	 */
2670 
2671 	.start			= musb_h_start,
2672 	.stop			= musb_h_stop,
2673 
2674 	.get_frame_number	= musb_h_get_frame_number,
2675 
2676 	.urb_enqueue		= musb_urb_enqueue,
2677 	.urb_dequeue		= musb_urb_dequeue,
2678 	.endpoint_disable	= musb_h_disable,
2679 
2680 #ifndef CONFIG_MUSB_PIO_ONLY
2681 	.map_urb_for_dma	= musb_map_urb_for_dma,
2682 	.unmap_urb_for_dma	= musb_unmap_urb_for_dma,
2683 #endif
2684 
2685 	.hub_status_data	= musb_hub_status_data,
2686 	.hub_control		= musb_hub_control,
2687 	.bus_suspend		= musb_bus_suspend,
2688 	.bus_resume		= musb_bus_resume,
2689 	/* .start_port_reset	= NULL, */
2690 	/* .hub_irq_enable	= NULL, */
2691 };
2692 
2693 int musb_host_alloc(struct musb *musb)
2694 {
2695 	struct device	*dev = musb->controller;
2696 
2697 	/* usbcore sets dev->driver_data to hcd, and sometimes uses that... */
2698 	musb->hcd = usb_create_hcd(&musb_hc_driver, dev, dev_name(dev));
2699 	if (!musb->hcd)
2700 		return -EINVAL;
2701 
2702 	*musb->hcd->hcd_priv = (unsigned long) musb;
2703 	musb->hcd->self.uses_pio_for_control = 1;
2704 	musb->hcd->uses_new_polling = 1;
2705 	musb->hcd->has_tt = 1;
2706 
2707 	return 0;
2708 }
2709 
2710 void musb_host_cleanup(struct musb *musb)
2711 {
2712 	if (musb->port_mode == MUSB_PERIPHERAL)
2713 		return;
2714 	usb_remove_hcd(musb->hcd);
2715 }
2716 
2717 void musb_host_free(struct musb *musb)
2718 {
2719 	usb_put_hcd(musb->hcd);
2720 }
2721 
2722 int musb_host_setup(struct musb *musb, int power_budget)
2723 {
2724 	int ret;
2725 	struct usb_hcd *hcd = musb->hcd;
2726 
2727 	if (musb->port_mode == MUSB_HOST) {
2728 		MUSB_HST_MODE(musb);
2729 		musb_set_state(musb, OTG_STATE_A_IDLE);
2730 	}
2731 
2732 	if (musb->xceiv) {
2733 		otg_set_host(musb->xceiv->otg, &hcd->self);
2734 		musb->xceiv->otg->host = &hcd->self;
2735 	} else {
2736 		phy_set_mode(musb->phy, PHY_MODE_USB_HOST);
2737 	}
2738 
2739 	/* don't support otg protocols */
2740 	hcd->self.otg_port = 0;
2741 	hcd->power_budget = 2 * (power_budget ? : 250);
2742 	hcd->skip_phy_initialization = 1;
2743 
2744 	ret = usb_add_hcd(hcd, 0, 0);
2745 	if (ret < 0)
2746 		return ret;
2747 
2748 	device_wakeup_enable(hcd->self.controller);
2749 	return 0;
2750 }
2751 
2752 void musb_host_resume_root_hub(struct musb *musb)
2753 {
2754 	usb_hcd_resume_root_hub(musb->hcd);
2755 }
2756 
2757 void musb_host_poke_root_hub(struct musb *musb)
2758 {
2759 	MUSB_HST_MODE(musb);
2760 	if (musb->hcd->status_urb)
2761 		usb_hcd_poll_rh_status(musb->hcd);
2762 	else
2763 		usb_hcd_resume_root_hub(musb->hcd);
2764 }
2765