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
73struct musb *hcd_to_musb(struct usb_hcd *hcd)
74{
75	return *(struct musb **) hcd->hcd_priv;
76}
77
78
79static 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 */
86static 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
121static 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 */
148static 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
164static 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
176static 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
184static 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 */
195static void
196musb_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:
265start:
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 */
277static 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 */
296static 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
390static 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 */
412static bool
413musb_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 */
513static void
514musb_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
572static 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
610static 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
625static 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 */
669static 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		}
834finish:
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 */
899static 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 */
978static 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 */
1054irqreturn_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);
1173done:
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 */
1195void 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
1263done:
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 */
1464static 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
1489static 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 */
1535static 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 */
1605static 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
1705static 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
1714static 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 */
1729void 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
1973finish:
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 */
1993static 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);
2100success:
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
2113static 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
2292done:
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 */
2308static 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
2363static 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);
2414done:
2415	spin_unlock_irqrestore(&musb->lock, flags);
2416	return ret;
2417}
2418
2419/* disable an endpoint */
2420static void
2421musb_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	}
2469exit:
2470	spin_unlock_irqrestore(&musb->lock, flags);
2471}
2472
2473static 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
2480static 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
2492static void musb_h_stop(struct usb_hcd *hcd)
2493{
2494	musb_stop(hcd_to_musb(hcd));
2495	hcd->state = HC_STATE_HALT;
2496}
2497
2498static 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
2535static 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
2550struct musb_temp_buffer {
2551	void *kmalloc_ptr;
2552	void *old_xfer_buffer;
2553	u8 data[];
2554};
2555
2556static 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
2584static 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
2622static 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
2648static 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
2662static 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
2694int 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
2711void musb_host_cleanup(struct musb *musb)
2712{
2713	if (musb->port_mode == MUSB_PERIPHERAL)
2714		return;
2715	usb_remove_hcd(musb->hcd);
2716}
2717
2718void musb_host_free(struct musb *musb)
2719{
2720	usb_put_hcd(musb->hcd);
2721}
2722
2723int 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
2753void musb_host_resume_root_hub(struct musb *musb)
2754{
2755	usb_hcd_resume_root_hub(musb->hcd);
2756}
2757
2758void 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