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#ifndef __UBOOT__
12#include <dm/device_compat.h>
13#include <dm/devres.h>
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/delay.h>
17#include <linux/sched.h>
18#include <linux/slab.h>
19#include <linux/errno.h>
20#include <linux/init.h>
21#include <linux/list.h>
22#include <linux/dma-mapping.h>
23#else
24#include <common.h>
25#include <dm.h>
26#include <dm/device_compat.h>
27#include <usb.h>
28#include <linux/bug.h>
29#include <linux/usb/usb_urb_compat.h>
30#include "linux-compat.h"
31#endif
32
33#include "musb_core.h"
34#include "musb_host.h"
35
36
37/* MUSB HOST status 22-mar-2006
38 *
39 * - There's still lots of partial code duplication for fault paths, so
40 *   they aren't handled as consistently as they need to be.
41 *
42 * - PIO mostly behaved when last tested.
43 *     + including ep0, with all usbtest cases 9, 10
44 *     + usbtest 14 (ep0out) doesn't seem to run at all
45 *     + double buffered OUT/TX endpoints saw stalls(!) with certain usbtest
46 *       configurations, but otherwise double buffering passes basic tests.
47 *     + for 2.6.N, for N > ~10, needs API changes for hcd framework.
48 *
49 * - DMA (CPPI) ... partially behaves, not currently recommended
50 *     + about 1/15 the speed of typical EHCI implementations (PCI)
51 *     + RX, all too often reqpkt seems to misbehave after tx
52 *     + TX, no known issues (other than evident silicon issue)
53 *
54 * - DMA (Mentor/OMAP) ...has at least toggle update problems
55 *
56 * - [23-feb-2009] minimal traffic scheduling to avoid bulk RX packet
57 *   starvation ... nothing yet for TX, interrupt, or bulk.
58 *
59 * - Not tested with HNP, but some SRP paths seem to behave.
60 *
61 * NOTE 24-August-2006:
62 *
63 * - Bulk traffic finally uses both sides of hardware ep1, freeing up an
64 *   extra endpoint for periodic use enabling hub + keybd + mouse.  That
65 *   mostly works, except that with "usbnet" it's easy to trigger cases
66 *   with "ping" where RX loses.  (a) ping to davinci, even "ping -f",
67 *   fine; but (b) ping _from_ davinci, even "ping -c 1", ICMP RX loses
68 *   although ARP RX wins.  (That test was done with a full speed link.)
69 */
70
71
72/*
73 * NOTE on endpoint usage:
74 *
75 * CONTROL transfers all go through ep0.  BULK ones go through dedicated IN
76 * and OUT endpoints ... hardware is dedicated for those "async" queue(s).
77 * (Yes, bulk _could_ use more of the endpoints than that, and would even
78 * benefit from it.)
79 *
80 * INTERUPPT and ISOCHRONOUS transfers are scheduled to the other endpoints.
81 * So far that scheduling is both dumb and optimistic:  the endpoint will be
82 * "claimed" until its software queue is no longer refilled.  No multiplexing
83 * of transfers between endpoints, or anything clever.
84 */
85
86
87static void musb_ep_program(struct musb *musb, u8 epnum,
88			struct urb *urb, int is_out,
89			u8 *buf, u32 offset, u32 len);
90
91/*
92 * Clear TX fifo. Needed to avoid BABBLE errors.
93 */
94static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
95{
96	struct musb	*musb = ep->musb;
97	void __iomem	*epio = ep->regs;
98	u16		csr;
99	u16		lastcsr = 0;
100	int		retries = 1000;
101
102	csr = musb_readw(epio, MUSB_TXCSR);
103	while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
104		if (csr != lastcsr)
105			dev_dbg(musb->controller, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
106		lastcsr = csr;
107		csr |= MUSB_TXCSR_FLUSHFIFO;
108		musb_writew(epio, MUSB_TXCSR, csr);
109		csr = musb_readw(epio, MUSB_TXCSR);
110		if (WARN(retries-- < 1,
111				"Could not flush host TX%d fifo: csr: %04x\n",
112				ep->epnum, csr))
113			return;
114		mdelay(1);
115	}
116}
117
118static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep)
119{
120	void __iomem	*epio = ep->regs;
121	u16		csr;
122	int		retries = 5;
123
124	/* scrub any data left in the fifo */
125	do {
126		csr = musb_readw(epio, MUSB_TXCSR);
127		if (!(csr & (MUSB_CSR0_TXPKTRDY | MUSB_CSR0_RXPKTRDY)))
128			break;
129		musb_writew(epio, MUSB_TXCSR, MUSB_CSR0_FLUSHFIFO);
130		csr = musb_readw(epio, MUSB_TXCSR);
131		udelay(10);
132	} while (--retries);
133
134	WARN(!retries, "Could not flush host TX%d fifo: csr: %04x\n",
135			ep->epnum, csr);
136
137	/* and reset for the next transfer */
138	musb_writew(epio, MUSB_TXCSR, 0);
139}
140
141/*
142 * Start transmit. Caller is responsible for locking shared resources.
143 * musb must be locked.
144 */
145static inline void musb_h_tx_start(struct musb_hw_ep *ep)
146{
147	u16	txcsr;
148
149	/* NOTE: no locks here; caller should lock and select EP */
150	if (ep->epnum) {
151		txcsr = musb_readw(ep->regs, MUSB_TXCSR);
152		txcsr |= MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_H_WZC_BITS;
153		musb_writew(ep->regs, MUSB_TXCSR, txcsr);
154	} else {
155		txcsr = MUSB_CSR0_H_SETUPPKT | MUSB_CSR0_TXPKTRDY;
156		musb_writew(ep->regs, MUSB_CSR0, txcsr);
157	}
158
159}
160
161static inline void musb_h_tx_dma_start(struct musb_hw_ep *ep)
162{
163	u16	txcsr;
164
165	/* NOTE: no locks here; caller should lock and select EP */
166	txcsr = musb_readw(ep->regs, MUSB_TXCSR);
167	txcsr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_H_WZC_BITS;
168	if (is_cppi_enabled())
169		txcsr |= MUSB_TXCSR_DMAMODE;
170	musb_writew(ep->regs, MUSB_TXCSR, txcsr);
171}
172
173static void musb_ep_set_qh(struct musb_hw_ep *ep, int is_in, struct musb_qh *qh)
174{
175	if (is_in != 0 || ep->is_shared_fifo)
176		ep->in_qh  = qh;
177	if (is_in == 0 || ep->is_shared_fifo)
178		ep->out_qh = qh;
179}
180
181static struct musb_qh *musb_ep_get_qh(struct musb_hw_ep *ep, int is_in)
182{
183	return is_in ? ep->in_qh : ep->out_qh;
184}
185
186/*
187 * Start the URB at the front of an endpoint's queue
188 * end must be claimed from the caller.
189 *
190 * Context: controller locked, irqs blocked
191 */
192static void
193musb_start_urb(struct musb *musb, int is_in, struct musb_qh *qh)
194{
195	u16			frame;
196	u32			len;
197	void __iomem		*mbase =  musb->mregs;
198	struct urb		*urb = next_urb(qh);
199	void			*buf = urb->transfer_buffer;
200	u32			offset = 0;
201	struct musb_hw_ep	*hw_ep = qh->hw_ep;
202	unsigned		pipe = urb->pipe;
203	u8			address = usb_pipedevice(pipe);
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#ifndef __UBOOT__
220	case USB_ENDPOINT_XFER_ISOC:
221		qh->iso_idx = 0;
222		qh->frame = 0;
223		offset = urb->iso_frame_desc[0].offset;
224		len = urb->iso_frame_desc[0].length;
225		break;
226#endif
227	default:		/* bulk, interrupt */
228		/* actual_length may be nonzero on retry paths */
229		buf = urb->transfer_buffer + urb->actual_length;
230		len = urb->transfer_buffer_length - urb->actual_length;
231	}
232
233	dev_dbg(musb->controller, "qh %p urb %p dev%d ep%d%s%s, hw_ep %d, %p/%d\n",
234			qh, urb, address, qh->epnum,
235			is_in ? "in" : "out",
236			({char *s; switch (qh->type) {
237			case USB_ENDPOINT_XFER_CONTROL:	s = ""; break;
238			case USB_ENDPOINT_XFER_BULK:	s = "-bulk"; break;
239#ifndef __UBOOT__
240			case USB_ENDPOINT_XFER_ISOC:	s = "-iso"; break;
241#endif
242			default:			s = "-intr"; break;
243			}; s; }),
244			epnum, buf + offset, len);
245
246	/* Configure endpoint */
247	musb_ep_set_qh(hw_ep, is_in, qh);
248	musb_ep_program(musb, epnum, urb, !is_in, buf, offset, len);
249
250	/* transmit may have more work: start it when it is time */
251	if (is_in)
252		return;
253
254	/* determine if the time is right for a periodic transfer */
255	switch (qh->type) {
256#ifndef __UBOOT__
257	case USB_ENDPOINT_XFER_ISOC:
258#endif
259	case USB_ENDPOINT_XFER_INT:
260		dev_dbg(musb->controller, "check whether there's still time for periodic Tx\n");
261		frame = musb_readw(mbase, MUSB_FRAME);
262		/* FIXME this doesn't implement that scheduling policy ...
263		 * or handle framecounter wrapping
264		 */
265#ifndef __UBOOT__
266		if ((urb->transfer_flags & URB_ISO_ASAP)
267				|| (frame >= urb->start_frame)) {
268			/* REVISIT the SOF irq handler shouldn't duplicate
269			 * this code; and we don't init urb->start_frame...
270			 */
271			qh->frame = 0;
272			goto start;
273		} else {
274#endif
275			qh->frame = urb->start_frame;
276			/* enable SOF interrupt so we can count down */
277			dev_dbg(musb->controller, "SOF for %d\n", epnum);
278#if 1 /* ifndef	CONFIG_ARCH_DAVINCI */
279			musb_writeb(mbase, MUSB_INTRUSBE, 0xff);
280#endif
281#ifndef __UBOOT__
282		}
283#endif
284		break;
285	default:
286start:
287		dev_dbg(musb->controller, "Start TX%d %s\n", epnum,
288			hw_ep->tx_channel ? "dma" : "pio");
289
290		if (!hw_ep->tx_channel)
291			musb_h_tx_start(hw_ep);
292		else if (is_cppi_enabled() || tusb_dma_omap())
293			musb_h_tx_dma_start(hw_ep);
294	}
295}
296
297/* Context: caller owns controller lock, IRQs are blocked */
298static void musb_giveback(struct musb *musb, struct urb *urb, int status)
299__releases(musb->lock)
300__acquires(musb->lock)
301{
302	dev_dbg(musb->controller,
303			"complete %p %pF (%d), dev%d ep%d%s, %d/%d\n",
304			urb, urb->complete, status,
305			usb_pipedevice(urb->pipe),
306			usb_pipeendpoint(urb->pipe),
307			usb_pipein(urb->pipe) ? "in" : "out",
308			urb->actual_length, urb->transfer_buffer_length
309			);
310
311	usb_hcd_unlink_urb_from_ep(musb_to_hcd(musb), urb);
312	spin_unlock(&musb->lock);
313	usb_hcd_giveback_urb(musb_to_hcd(musb), urb, status);
314	spin_lock(&musb->lock);
315}
316
317/* For bulk/interrupt endpoints only */
318static inline void musb_save_toggle(struct musb_qh *qh, int is_in,
319				    struct urb *urb)
320{
321	void __iomem		*epio = qh->hw_ep->regs;
322	u16			csr;
323
324	/*
325	 * FIXME: the current Mentor DMA code seems to have
326	 * problems getting toggle correct.
327	 */
328
329	if (is_in)
330		csr = musb_readw(epio, MUSB_RXCSR) & MUSB_RXCSR_H_DATATOGGLE;
331	else
332		csr = musb_readw(epio, MUSB_TXCSR) & MUSB_TXCSR_H_DATATOGGLE;
333
334	usb_settoggle(urb->dev, qh->epnum, !is_in, csr ? 1 : 0);
335}
336
337/*
338 * Advance this hardware endpoint's queue, completing the specified URB and
339 * advancing to either the next URB queued to that qh, or else invalidating
340 * that qh and advancing to the next qh scheduled after the current one.
341 *
342 * Context: caller owns controller lock, IRQs are blocked
343 */
344static void musb_advance_schedule(struct musb *musb, struct urb *urb,
345				  struct musb_hw_ep *hw_ep, int is_in)
346{
347	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, is_in);
348	struct musb_hw_ep	*ep = qh->hw_ep;
349	int			ready = qh->is_ready;
350	int			status;
351
352	status = (urb->status == -EINPROGRESS) ? 0 : urb->status;
353
354	/* save toggle eagerly, for paranoia */
355	switch (qh->type) {
356	case USB_ENDPOINT_XFER_BULK:
357	case USB_ENDPOINT_XFER_INT:
358		musb_save_toggle(qh, is_in, urb);
359		break;
360#ifndef __UBOOT__
361	case USB_ENDPOINT_XFER_ISOC:
362		if (status == 0 && urb->error_count)
363			status = -EXDEV;
364		break;
365#endif
366	}
367
368	qh->is_ready = 0;
369	musb_giveback(musb, urb, status);
370	qh->is_ready = ready;
371
372	/* reclaim resources (and bandwidth) ASAP; deschedule it, and
373	 * invalidate qh as soon as list_empty(&hep->urb_list)
374	 */
375	if (list_empty(&qh->hep->urb_list)) {
376		struct list_head	*head;
377		struct dma_controller	*dma = musb->dma_controller;
378
379		if (is_in) {
380			ep->rx_reinit = 1;
381			if (ep->rx_channel) {
382				dma->channel_release(ep->rx_channel);
383				ep->rx_channel = NULL;
384			}
385		} else {
386			ep->tx_reinit = 1;
387			if (ep->tx_channel) {
388				dma->channel_release(ep->tx_channel);
389				ep->tx_channel = NULL;
390			}
391		}
392
393		/* Clobber old pointers to this qh */
394		musb_ep_set_qh(ep, is_in, NULL);
395		qh->hep->hcpriv = NULL;
396
397		switch (qh->type) {
398
399		case USB_ENDPOINT_XFER_CONTROL:
400		case USB_ENDPOINT_XFER_BULK:
401			/* fifo policy for these lists, except that NAKing
402			 * should rotate a qh to the end (for fairness).
403			 */
404			if (qh->mux == 1) {
405				head = qh->ring.prev;
406				list_del(&qh->ring);
407				kfree(qh);
408				qh = first_qh(head);
409				break;
410			}
411
412		case USB_ENDPOINT_XFER_ISOC:
413		case USB_ENDPOINT_XFER_INT:
414			/* this is where periodic bandwidth should be
415			 * de-allocated if it's tracked and allocated;
416			 * and where we'd update the schedule tree...
417			 */
418			kfree(qh);
419			qh = NULL;
420			break;
421		}
422	}
423
424	if (qh != NULL && qh->is_ready) {
425		dev_dbg(musb->controller, "... next ep%d %cX urb %p\n",
426		    hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh));
427		musb_start_urb(musb, is_in, qh);
428	}
429}
430
431static u16 musb_h_flush_rxfifo(struct musb_hw_ep *hw_ep, u16 csr)
432{
433	/* we don't want fifo to fill itself again;
434	 * ignore dma (various models),
435	 * leave toggle alone (may not have been saved yet)
436	 */
437	csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_RXPKTRDY;
438	csr &= ~(MUSB_RXCSR_H_REQPKT
439		| MUSB_RXCSR_H_AUTOREQ
440		| MUSB_RXCSR_AUTOCLEAR);
441
442	/* write 2x to allow double buffering */
443	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
444	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
445
446	/* flush writebuffer */
447	return musb_readw(hw_ep->regs, MUSB_RXCSR);
448}
449
450/*
451 * PIO RX for a packet (or part of it).
452 */
453static bool
454musb_host_packet_rx(struct musb *musb, struct urb *urb, u8 epnum, u8 iso_err)
455{
456	u16			rx_count;
457	u8			*buf;
458	u16			csr;
459	bool			done = false;
460	u32			length;
461	int			do_flush = 0;
462	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
463	void __iomem		*epio = hw_ep->regs;
464	struct musb_qh		*qh = hw_ep->in_qh;
465	int			pipe = urb->pipe;
466	void			*buffer = urb->transfer_buffer;
467
468	/* musb_ep_select(mbase, epnum); */
469	rx_count = musb_readw(epio, MUSB_RXCOUNT);
470	dev_dbg(musb->controller, "RX%d count %d, buffer %p len %d/%d\n", epnum, rx_count,
471			urb->transfer_buffer, qh->offset,
472			urb->transfer_buffer_length);
473
474	/* unload FIFO */
475#ifndef __UBOOT__
476	if (usb_pipeisoc(pipe)) {
477		int					status = 0;
478		struct usb_iso_packet_descriptor	*d;
479
480		if (iso_err) {
481			status = -EILSEQ;
482			urb->error_count++;
483		}
484
485		d = urb->iso_frame_desc + qh->iso_idx;
486		buf = buffer + d->offset;
487		length = d->length;
488		if (rx_count > length) {
489			if (status == 0) {
490				status = -EOVERFLOW;
491				urb->error_count++;
492			}
493			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
494			do_flush = 1;
495		} else
496			length = rx_count;
497		urb->actual_length += length;
498		d->actual_length = length;
499
500		d->status = status;
501
502		/* see if we are done */
503		done = (++qh->iso_idx >= urb->number_of_packets);
504	} else {
505#endif
506		/* non-isoch */
507		buf = buffer + qh->offset;
508		length = urb->transfer_buffer_length - qh->offset;
509		if (rx_count > length) {
510			if (urb->status == -EINPROGRESS)
511				urb->status = -EOVERFLOW;
512			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
513			do_flush = 1;
514		} else
515			length = rx_count;
516		urb->actual_length += length;
517		qh->offset += length;
518
519		/* see if we are done */
520		done = (urb->actual_length == urb->transfer_buffer_length)
521			|| (rx_count < qh->maxpacket)
522			|| (urb->status != -EINPROGRESS);
523		if (done
524				&& (urb->status == -EINPROGRESS)
525				&& (urb->transfer_flags & URB_SHORT_NOT_OK)
526				&& (urb->actual_length
527					< urb->transfer_buffer_length))
528			urb->status = -EREMOTEIO;
529#ifndef __UBOOT__
530	}
531#endif
532
533	musb_read_fifo(hw_ep, length, buf);
534
535	csr = musb_readw(epio, MUSB_RXCSR);
536	csr |= MUSB_RXCSR_H_WZC_BITS;
537	if (unlikely(do_flush))
538		musb_h_flush_rxfifo(hw_ep, csr);
539	else {
540		/* REVISIT this assumes AUTOCLEAR is never set */
541		csr &= ~(MUSB_RXCSR_RXPKTRDY | MUSB_RXCSR_H_REQPKT);
542		if (!done)
543			csr |= MUSB_RXCSR_H_REQPKT;
544		musb_writew(epio, MUSB_RXCSR, csr);
545	}
546
547	return done;
548}
549
550/* we don't always need to reinit a given side of an endpoint...
551 * when we do, use tx/rx reinit routine and then construct a new CSR
552 * to address data toggle, NYET, and DMA or PIO.
553 *
554 * it's possible that driver bugs (especially for DMA) or aborting a
555 * transfer might have left the endpoint busier than it should be.
556 * the busy/not-empty tests are basically paranoia.
557 */
558static void
559musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep)
560{
561	u16	csr;
562
563	/* NOTE:  we know the "rx" fifo reinit never triggers for ep0.
564	 * That always uses tx_reinit since ep0 repurposes TX register
565	 * offsets; the initial SETUP packet is also a kind of OUT.
566	 */
567
568	/* if programmed for Tx, put it in RX mode */
569	if (ep->is_shared_fifo) {
570		csr = musb_readw(ep->regs, MUSB_TXCSR);
571		if (csr & MUSB_TXCSR_MODE) {
572			musb_h_tx_flush_fifo(ep);
573			csr = musb_readw(ep->regs, MUSB_TXCSR);
574			musb_writew(ep->regs, MUSB_TXCSR,
575				    csr | MUSB_TXCSR_FRCDATATOG);
576		}
577
578		/*
579		 * Clear the MODE bit (and everything else) to enable Rx.
580		 * NOTE: we mustn't clear the DMAMODE bit before DMAENAB.
581		 */
582		if (csr & MUSB_TXCSR_DMAMODE)
583			musb_writew(ep->regs, MUSB_TXCSR, MUSB_TXCSR_DMAMODE);
584		musb_writew(ep->regs, MUSB_TXCSR, 0);
585
586	/* scrub all previous state, clearing toggle */
587	} else {
588		csr = musb_readw(ep->regs, MUSB_RXCSR);
589		if (csr & MUSB_RXCSR_RXPKTRDY)
590			WARNING("rx%d, packet/%d ready?\n", ep->epnum,
591				musb_readw(ep->regs, MUSB_RXCOUNT));
592
593		musb_h_flush_rxfifo(ep, MUSB_RXCSR_CLRDATATOG);
594	}
595
596	/* target addr and (for multipoint) hub addr/port */
597	if (musb->is_multipoint) {
598		musb_write_rxfunaddr(ep->target_regs, qh->addr_reg);
599		musb_write_rxhubaddr(ep->target_regs, qh->h_addr_reg);
600		musb_write_rxhubport(ep->target_regs, qh->h_port_reg);
601
602	} else
603		musb_writeb(musb->mregs, MUSB_FADDR, qh->addr_reg);
604
605	/* protocol/endpoint, interval/NAKlimit, i/o size */
606	musb_writeb(ep->regs, MUSB_RXTYPE, qh->type_reg);
607	musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);
608	/* NOTE: bulk combining rewrites high bits of maxpacket */
609	/* Set RXMAXP with the FIFO size of the endpoint
610	 * to disable double buffer mode.
611	 */
612	if (musb->double_buffer_not_ok)
613		musb_writew(ep->regs, MUSB_RXMAXP, ep->max_packet_sz_rx);
614	else
615		musb_writew(ep->regs, MUSB_RXMAXP,
616				qh->maxpacket | ((qh->hb_mult - 1) << 11));
617
618	ep->rx_reinit = 0;
619}
620
621static bool musb_tx_dma_program(struct dma_controller *dma,
622		struct musb_hw_ep *hw_ep, struct musb_qh *qh,
623		struct urb *urb, u32 offset, u32 length)
624{
625	struct dma_channel	*channel = hw_ep->tx_channel;
626	void __iomem		*epio = hw_ep->regs;
627	u16			pkt_size = qh->maxpacket;
628	u16			csr;
629	u8			mode;
630
631#ifdef	CONFIG_USB_INVENTRA_DMA
632	if (length > channel->max_len)
633		length = channel->max_len;
634
635	csr = musb_readw(epio, MUSB_TXCSR);
636	if (length > pkt_size) {
637		mode = 1;
638		csr |= MUSB_TXCSR_DMAMODE | MUSB_TXCSR_DMAENAB;
639		/* autoset shouldn't be set in high bandwidth */
640		if (qh->hb_mult == 1)
641			csr |= MUSB_TXCSR_AUTOSET;
642	} else {
643		mode = 0;
644		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAMODE);
645		csr |= MUSB_TXCSR_DMAENAB; /* against programmer's guide */
646	}
647	channel->desired_mode = mode;
648	musb_writew(epio, MUSB_TXCSR, csr);
649#else
650	if (!is_cppi_enabled() && !tusb_dma_omap())
651		return false;
652
653	channel->actual_len = 0;
654
655	/*
656	 * TX uses "RNDIS" mode automatically but needs help
657	 * to identify the zero-length-final-packet case.
658	 */
659	mode = (urb->transfer_flags & URB_ZERO_PACKET) ? 1 : 0;
660#endif
661
662	qh->segsize = length;
663
664	/*
665	 * Ensure the data reaches to main memory before starting
666	 * DMA transfer
667	 */
668	wmb();
669
670	if (!dma->channel_program(channel, pkt_size, mode,
671			urb->transfer_dma + offset, length)) {
672		dma->channel_release(channel);
673		hw_ep->tx_channel = NULL;
674
675		csr = musb_readw(epio, MUSB_TXCSR);
676		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
677		musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_H_WZC_BITS);
678		return false;
679	}
680	return true;
681}
682
683/*
684 * Program an HDRC endpoint as per the given URB
685 * Context: irqs blocked, controller lock held
686 */
687static void musb_ep_program(struct musb *musb, u8 epnum,
688			struct urb *urb, int is_out,
689			u8 *buf, u32 offset, u32 len)
690{
691	struct dma_controller	*dma_controller;
692	struct dma_channel	*dma_channel;
693	u8			dma_ok;
694	void __iomem		*mbase = musb->mregs;
695	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
696	void __iomem		*epio = hw_ep->regs;
697	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, !is_out);
698	u16			packet_sz = qh->maxpacket;
699
700	dev_dbg(musb->controller, "%s hw%d urb %p spd%d dev%d ep%d%s "
701				"h_addr%02x h_port%02x bytes %d\n",
702			is_out ? "-->" : "<--",
703			epnum, urb, urb->dev->speed,
704			qh->addr_reg, qh->epnum, is_out ? "out" : "in",
705			qh->h_addr_reg, qh->h_port_reg,
706			len);
707
708	musb_ep_select(mbase, epnum);
709
710	/* candidate for DMA? */
711	dma_controller = musb->dma_controller;
712	if (is_dma_capable() && epnum && dma_controller) {
713		dma_channel = is_out ? hw_ep->tx_channel : hw_ep->rx_channel;
714		if (!dma_channel) {
715			dma_channel = dma_controller->channel_alloc(
716					dma_controller, hw_ep, is_out);
717			if (is_out)
718				hw_ep->tx_channel = dma_channel;
719			else
720				hw_ep->rx_channel = dma_channel;
721		}
722	} else
723		dma_channel = NULL;
724
725	/* make sure we clear DMAEnab, autoSet bits from previous run */
726
727	/* OUT/transmit/EP0 or IN/receive? */
728	if (is_out) {
729		u16	csr;
730		u16	int_txe;
731		u16	load_count;
732
733		csr = musb_readw(epio, MUSB_TXCSR);
734
735		/* disable interrupt in case we flush */
736		int_txe = musb_readw(mbase, MUSB_INTRTXE);
737		musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
738
739		/* general endpoint setup */
740		if (epnum) {
741			/* flush all old state, set default */
742			musb_h_tx_flush_fifo(hw_ep);
743
744			/*
745			 * We must not clear the DMAMODE bit before or in
746			 * the same cycle with the DMAENAB bit, so we clear
747			 * the latter first...
748			 */
749			csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
750					| MUSB_TXCSR_AUTOSET
751					| MUSB_TXCSR_DMAENAB
752					| MUSB_TXCSR_FRCDATATOG
753					| MUSB_TXCSR_H_RXSTALL
754					| MUSB_TXCSR_H_ERROR
755					| MUSB_TXCSR_TXPKTRDY
756					);
757			csr |= MUSB_TXCSR_MODE;
758
759			if (usb_gettoggle(urb->dev, qh->epnum, 1))
760				csr |= MUSB_TXCSR_H_WR_DATATOGGLE
761					| MUSB_TXCSR_H_DATATOGGLE;
762			else
763				csr |= MUSB_TXCSR_CLRDATATOG;
764
765			musb_writew(epio, MUSB_TXCSR, csr);
766			/* REVISIT may need to clear FLUSHFIFO ... */
767			csr &= ~MUSB_TXCSR_DMAMODE;
768			musb_writew(epio, MUSB_TXCSR, csr);
769			csr = musb_readw(epio, MUSB_TXCSR);
770		} else {
771			/* endpoint 0: just flush */
772			musb_h_ep0_flush_fifo(hw_ep);
773		}
774
775		/* target addr and (for multipoint) hub addr/port */
776		if (musb->is_multipoint) {
777			musb_write_txfunaddr(mbase, epnum, qh->addr_reg);
778			musb_write_txhubaddr(mbase, epnum, qh->h_addr_reg);
779			musb_write_txhubport(mbase, epnum, qh->h_port_reg);
780/* FIXME if !epnum, do the same for RX ... */
781		} else
782			musb_writeb(mbase, MUSB_FADDR, qh->addr_reg);
783
784		/* protocol/endpoint/interval/NAKlimit */
785		if (epnum) {
786			musb_writeb(epio, MUSB_TXTYPE, qh->type_reg);
787			if (musb->double_buffer_not_ok)
788				musb_writew(epio, MUSB_TXMAXP,
789						hw_ep->max_packet_sz_tx);
790			else if (can_bulk_split(musb, qh->type))
791				musb_writew(epio, MUSB_TXMAXP, packet_sz
792					| ((hw_ep->max_packet_sz_tx /
793						packet_sz) - 1) << 11);
794			else
795				musb_writew(epio, MUSB_TXMAXP,
796						qh->maxpacket |
797						((qh->hb_mult - 1) << 11));
798			musb_writeb(epio, MUSB_TXINTERVAL, qh->intv_reg);
799		} else {
800			musb_writeb(epio, MUSB_NAKLIMIT0, qh->intv_reg);
801			if (musb->is_multipoint)
802				musb_writeb(epio, MUSB_TYPE0,
803						qh->type_reg);
804		}
805
806		if (can_bulk_split(musb, qh->type))
807			load_count = min((u32) hw_ep->max_packet_sz_tx,
808						len);
809		else
810			load_count = min((u32) packet_sz, len);
811
812		if (dma_channel && musb_tx_dma_program(dma_controller,
813					hw_ep, qh, urb, offset, len))
814			load_count = 0;
815
816		if (load_count) {
817			/* PIO to load FIFO */
818			qh->segsize = load_count;
819			musb_write_fifo(hw_ep, load_count, buf);
820		}
821
822		/* re-enable interrupt */
823		musb_writew(mbase, MUSB_INTRTXE, int_txe);
824
825	/* IN/receive */
826	} else {
827		u16	csr;
828
829		if (hw_ep->rx_reinit) {
830			musb_rx_reinit(musb, qh, hw_ep);
831
832			/* init new state: toggle and NYET, maybe DMA later */
833			if (usb_gettoggle(urb->dev, qh->epnum, 0))
834				csr = MUSB_RXCSR_H_WR_DATATOGGLE
835					| MUSB_RXCSR_H_DATATOGGLE;
836			else
837				csr = 0;
838			if (qh->type == USB_ENDPOINT_XFER_INT)
839				csr |= MUSB_RXCSR_DISNYET;
840
841		} else {
842			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
843
844			if (csr & (MUSB_RXCSR_RXPKTRDY
845					| MUSB_RXCSR_DMAENAB
846					| MUSB_RXCSR_H_REQPKT))
847				ERR("broken !rx_reinit, ep%d csr %04x\n",
848						hw_ep->epnum, csr);
849
850			/* scrub any stale state, leaving toggle alone */
851			csr &= MUSB_RXCSR_DISNYET;
852		}
853
854		/* kick things off */
855
856		if ((is_cppi_enabled() || tusb_dma_omap()) && dma_channel) {
857			/* Candidate for DMA */
858			dma_channel->actual_len = 0L;
859			qh->segsize = len;
860
861			/* AUTOREQ is in a DMA register */
862			musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
863			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
864
865			/*
866			 * Unless caller treats short RX transfers as
867			 * errors, we dare not queue multiple transfers.
868			 */
869			dma_ok = dma_controller->channel_program(dma_channel,
870					packet_sz, !(urb->transfer_flags &
871						     URB_SHORT_NOT_OK),
872					urb->transfer_dma + offset,
873					qh->segsize);
874			if (!dma_ok) {
875				dma_controller->channel_release(dma_channel);
876				hw_ep->rx_channel = dma_channel = NULL;
877			} else
878				csr |= MUSB_RXCSR_DMAENAB;
879		}
880
881		csr |= MUSB_RXCSR_H_REQPKT;
882		dev_dbg(musb->controller, "RXCSR%d := %04x\n", epnum, csr);
883		musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
884		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
885	}
886}
887
888
889/*
890 * Service the default endpoint (ep0) as host.
891 * Return true until it's time to start the status stage.
892 */
893static bool musb_h_ep0_continue(struct musb *musb, u16 len, struct urb *urb)
894{
895	bool			 more = false;
896	u8			*fifo_dest = NULL;
897	u16			fifo_count = 0;
898	struct musb_hw_ep	*hw_ep = musb->control_ep;
899	struct musb_qh		*qh = hw_ep->in_qh;
900	struct usb_ctrlrequest	*request;
901
902	switch (musb->ep0_stage) {
903	case MUSB_EP0_IN:
904		fifo_dest = urb->transfer_buffer + urb->actual_length;
905		fifo_count = min_t(size_t, len, urb->transfer_buffer_length -
906				   urb->actual_length);
907		if (fifo_count < len)
908			urb->status = -EOVERFLOW;
909
910		musb_read_fifo(hw_ep, fifo_count, fifo_dest);
911
912		urb->actual_length += fifo_count;
913		if (len < qh->maxpacket) {
914			/* always terminate on short read; it's
915			 * rarely reported as an error.
916			 */
917		} else if (urb->actual_length <
918				urb->transfer_buffer_length)
919			more = true;
920		break;
921	case MUSB_EP0_START:
922		request = (struct usb_ctrlrequest *) urb->setup_packet;
923
924		if (!request->wLength) {
925			dev_dbg(musb->controller, "start no-DATA\n");
926			break;
927		} else if (request->bRequestType & USB_DIR_IN) {
928			dev_dbg(musb->controller, "start IN-DATA\n");
929			musb->ep0_stage = MUSB_EP0_IN;
930			more = true;
931			break;
932		} else {
933			dev_dbg(musb->controller, "start OUT-DATA\n");
934			musb->ep0_stage = MUSB_EP0_OUT;
935			more = true;
936		}
937		/* FALLTHROUGH */
938	case MUSB_EP0_OUT:
939		fifo_count = min_t(size_t, qh->maxpacket,
940				   urb->transfer_buffer_length -
941				   urb->actual_length);
942		if (fifo_count) {
943			fifo_dest = (u8 *) (urb->transfer_buffer
944					+ urb->actual_length);
945			dev_dbg(musb->controller, "Sending %d byte%s to ep0 fifo %p\n",
946					fifo_count,
947					(fifo_count == 1) ? "" : "s",
948					fifo_dest);
949			musb_write_fifo(hw_ep, fifo_count, fifo_dest);
950
951			urb->actual_length += fifo_count;
952			more = true;
953		}
954		break;
955	default:
956		ERR("bogus ep0 stage %d\n", musb->ep0_stage);
957		break;
958	}
959
960	return more;
961}
962
963/*
964 * Handle default endpoint interrupt as host. Only called in IRQ time
965 * from musb_interrupt().
966 *
967 * called with controller irqlocked
968 */
969irqreturn_t musb_h_ep0_irq(struct musb *musb)
970{
971	struct urb		*urb;
972	u16			csr, len;
973	int			status = 0;
974	void __iomem		*mbase = musb->mregs;
975	struct musb_hw_ep	*hw_ep = musb->control_ep;
976	void __iomem		*epio = hw_ep->regs;
977	struct musb_qh		*qh = hw_ep->in_qh;
978	bool			complete = false;
979	irqreturn_t		retval = IRQ_NONE;
980
981	/* ep0 only has one queue, "in" */
982	urb = next_urb(qh);
983
984	musb_ep_select(mbase, 0);
985	csr = musb_readw(epio, MUSB_CSR0);
986	len = (csr & MUSB_CSR0_RXPKTRDY)
987			? musb_readb(epio, MUSB_COUNT0)
988			: 0;
989
990	dev_dbg(musb->controller, "<== csr0 %04x, qh %p, count %d, urb %p, stage %d\n",
991		csr, qh, len, urb, musb->ep0_stage);
992
993	/* if we just did status stage, we are done */
994	if (MUSB_EP0_STATUS == musb->ep0_stage) {
995		retval = IRQ_HANDLED;
996		complete = true;
997	}
998
999	/* prepare status */
1000	if (csr & MUSB_CSR0_H_RXSTALL) {
1001		dev_dbg(musb->controller, "STALLING ENDPOINT\n");
1002		status = -EPIPE;
1003
1004	} else if (csr & MUSB_CSR0_H_ERROR) {
1005		dev_dbg(musb->controller, "no response, csr0 %04x\n", csr);
1006		status = -EPROTO;
1007
1008	} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
1009		dev_dbg(musb->controller, "control NAK timeout\n");
1010
1011		/* NOTE:  this code path would be a good place to PAUSE a
1012		 * control transfer, if another one is queued, so that
1013		 * ep0 is more likely to stay busy.  That's already done
1014		 * for bulk RX transfers.
1015		 *
1016		 * if (qh->ring.next != &musb->control), then
1017		 * we have a candidate... NAKing is *NOT* an error
1018		 */
1019		musb_writew(epio, MUSB_CSR0, 0);
1020		retval = IRQ_HANDLED;
1021	}
1022
1023	if (status) {
1024		dev_dbg(musb->controller, "aborting\n");
1025		retval = IRQ_HANDLED;
1026		if (urb)
1027			urb->status = status;
1028		complete = true;
1029
1030		/* use the proper sequence to abort the transfer */
1031		if (csr & MUSB_CSR0_H_REQPKT) {
1032			csr &= ~MUSB_CSR0_H_REQPKT;
1033			musb_writew(epio, MUSB_CSR0, csr);
1034			csr &= ~MUSB_CSR0_H_NAKTIMEOUT;
1035			musb_writew(epio, MUSB_CSR0, csr);
1036		} else {
1037			musb_h_ep0_flush_fifo(hw_ep);
1038		}
1039
1040		musb_writeb(epio, MUSB_NAKLIMIT0, 0);
1041
1042		/* clear it */
1043		musb_writew(epio, MUSB_CSR0, 0);
1044	}
1045
1046	if (unlikely(!urb)) {
1047		/* stop endpoint since we have no place for its data, this
1048		 * SHOULD NEVER HAPPEN! */
1049		ERR("no URB for end 0\n");
1050
1051		musb_h_ep0_flush_fifo(hw_ep);
1052		goto done;
1053	}
1054
1055	if (!complete) {
1056		/* call common logic and prepare response */
1057		if (musb_h_ep0_continue(musb, len, urb)) {
1058			/* more packets required */
1059			csr = (MUSB_EP0_IN == musb->ep0_stage)
1060				?  MUSB_CSR0_H_REQPKT : MUSB_CSR0_TXPKTRDY;
1061		} else {
1062			/* data transfer complete; perform status phase */
1063			if (usb_pipeout(urb->pipe)
1064					|| !urb->transfer_buffer_length)
1065				csr = MUSB_CSR0_H_STATUSPKT
1066					| MUSB_CSR0_H_REQPKT;
1067			else
1068				csr = MUSB_CSR0_H_STATUSPKT
1069					| MUSB_CSR0_TXPKTRDY;
1070
1071			/* flag status stage */
1072			musb->ep0_stage = MUSB_EP0_STATUS;
1073
1074			dev_dbg(musb->controller, "ep0 STATUS, csr %04x\n", csr);
1075
1076		}
1077		musb_writew(epio, MUSB_CSR0, csr);
1078		retval = IRQ_HANDLED;
1079	} else
1080		musb->ep0_stage = MUSB_EP0_IDLE;
1081
1082	/* call completion handler if done */
1083	if (complete)
1084		musb_advance_schedule(musb, urb, hw_ep, 1);
1085done:
1086	return retval;
1087}
1088
1089
1090#ifdef CONFIG_USB_INVENTRA_DMA
1091
1092/* Host side TX (OUT) using Mentor DMA works as follows:
1093	submit_urb ->
1094		- if queue was empty, Program Endpoint
1095		- ... which starts DMA to fifo in mode 1 or 0
1096
1097	DMA Isr (transfer complete) -> TxAvail()
1098		- Stop DMA (~DmaEnab)	(<--- Alert ... currently happens
1099					only in musb_cleanup_urb)
1100		- TxPktRdy has to be set in mode 0 or for
1101			short packets in mode 1.
1102*/
1103
1104#endif
1105
1106/* Service a Tx-Available or dma completion irq for the endpoint */
1107void musb_host_tx(struct musb *musb, u8 epnum)
1108{
1109	int			pipe;
1110	bool			done = false;
1111	u16			tx_csr;
1112	size_t			length = 0;
1113	size_t			offset = 0;
1114	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1115	void __iomem		*epio = hw_ep->regs;
1116	struct musb_qh		*qh = hw_ep->out_qh;
1117	struct urb		*urb = next_urb(qh);
1118	u32			status = 0;
1119	void __iomem		*mbase = musb->mregs;
1120	struct dma_channel	*dma;
1121	bool			transfer_pending = false;
1122
1123	musb_ep_select(mbase, epnum);
1124	tx_csr = musb_readw(epio, MUSB_TXCSR);
1125
1126	/* with CPPI, DMA sometimes triggers "extra" irqs */
1127	if (!urb) {
1128		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1129		return;
1130	}
1131
1132	pipe = urb->pipe;
1133	dma = is_dma_capable() ? hw_ep->tx_channel : NULL;
1134	dev_dbg(musb->controller, "OUT/TX%d end, csr %04x%s\n", epnum, tx_csr,
1135			dma ? ", dma" : "");
1136
1137	/* check for errors */
1138	if (tx_csr & MUSB_TXCSR_H_RXSTALL) {
1139		/* dma was disabled, fifo flushed */
1140		dev_dbg(musb->controller, "TX end %d stall\n", epnum);
1141
1142		/* stall; record URB status */
1143		status = -EPIPE;
1144
1145	} else if (tx_csr & MUSB_TXCSR_H_ERROR) {
1146		/* (NON-ISO) dma was disabled, fifo flushed */
1147		dev_dbg(musb->controller, "TX 3strikes on ep=%d\n", epnum);
1148
1149		status = -ETIMEDOUT;
1150
1151	} else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) {
1152		dev_dbg(musb->controller, "TX end=%d device not responding\n", epnum);
1153
1154		/* NOTE:  this code path would be a good place to PAUSE a
1155		 * transfer, if there's some other (nonperiodic) tx urb
1156		 * that could use this fifo.  (dma complicates it...)
1157		 * That's already done for bulk RX transfers.
1158		 *
1159		 * if (bulk && qh->ring.next != &musb->out_bulk), then
1160		 * we have a candidate... NAKing is *NOT* an error
1161		 */
1162		musb_ep_select(mbase, epnum);
1163		musb_writew(epio, MUSB_TXCSR,
1164				MUSB_TXCSR_H_WZC_BITS
1165				| MUSB_TXCSR_TXPKTRDY);
1166		return;
1167	}
1168
1169	if (status) {
1170		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1171			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1172			(void) musb->dma_controller->channel_abort(dma);
1173		}
1174
1175		/* do the proper sequence to abort the transfer in the
1176		 * usb core; the dma engine should already be stopped.
1177		 */
1178		musb_h_tx_flush_fifo(hw_ep);
1179		tx_csr &= ~(MUSB_TXCSR_AUTOSET
1180				| MUSB_TXCSR_DMAENAB
1181				| MUSB_TXCSR_H_ERROR
1182				| MUSB_TXCSR_H_RXSTALL
1183				| MUSB_TXCSR_H_NAKTIMEOUT
1184				);
1185
1186		musb_ep_select(mbase, epnum);
1187		musb_writew(epio, MUSB_TXCSR, tx_csr);
1188		/* REVISIT may need to clear FLUSHFIFO ... */
1189		musb_writew(epio, MUSB_TXCSR, tx_csr);
1190		musb_writeb(epio, MUSB_TXINTERVAL, 0);
1191
1192		done = true;
1193	}
1194
1195	/* second cppi case */
1196	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1197		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1198		return;
1199	}
1200
1201	if (is_dma_capable() && dma && !status) {
1202		/*
1203		 * DMA has completed.  But if we're using DMA mode 1 (multi
1204		 * packet DMA), we need a terminal TXPKTRDY interrupt before
1205		 * we can consider this transfer completed, lest we trash
1206		 * its last packet when writing the next URB's data.  So we
1207		 * switch back to mode 0 to get that interrupt; we'll come
1208		 * back here once it happens.
1209		 */
1210		if (tx_csr & MUSB_TXCSR_DMAMODE) {
1211			/*
1212			 * We shouldn't clear DMAMODE with DMAENAB set; so
1213			 * clear them in a safe order.  That should be OK
1214			 * once TXPKTRDY has been set (and I've never seen
1215			 * it being 0 at this moment -- DMA interrupt latency
1216			 * is significant) but if it hasn't been then we have
1217			 * no choice but to stop being polite and ignore the
1218			 * programmer's guide... :-)
1219			 *
1220			 * Note that we must write TXCSR with TXPKTRDY cleared
1221			 * in order not to re-trigger the packet send (this bit
1222			 * can't be cleared by CPU), and there's another caveat:
1223			 * TXPKTRDY may be set shortly and then cleared in the
1224			 * double-buffered FIFO mode, so we do an extra TXCSR
1225			 * read for debouncing...
1226			 */
1227			tx_csr &= musb_readw(epio, MUSB_TXCSR);
1228			if (tx_csr & MUSB_TXCSR_TXPKTRDY) {
1229				tx_csr &= ~(MUSB_TXCSR_DMAENAB |
1230					    MUSB_TXCSR_TXPKTRDY);
1231				musb_writew(epio, MUSB_TXCSR,
1232					    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1233			}
1234			tx_csr &= ~(MUSB_TXCSR_DMAMODE |
1235				    MUSB_TXCSR_TXPKTRDY);
1236			musb_writew(epio, MUSB_TXCSR,
1237				    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1238
1239			/*
1240			 * There is no guarantee that we'll get an interrupt
1241			 * after clearing DMAMODE as we might have done this
1242			 * too late (after TXPKTRDY was cleared by controller).
1243			 * Re-read TXCSR as we have spoiled its previous value.
1244			 */
1245			tx_csr = musb_readw(epio, MUSB_TXCSR);
1246		}
1247
1248		/*
1249		 * We may get here from a DMA completion or TXPKTRDY interrupt.
1250		 * In any case, we must check the FIFO status here and bail out
1251		 * only if the FIFO still has data -- that should prevent the
1252		 * "missed" TXPKTRDY interrupts and deal with double-buffered
1253		 * FIFO mode too...
1254		 */
1255		if (tx_csr & (MUSB_TXCSR_FIFONOTEMPTY | MUSB_TXCSR_TXPKTRDY)) {
1256			dev_dbg(musb->controller, "DMA complete but packet still in FIFO, "
1257			    "CSR %04x\n", tx_csr);
1258			return;
1259		}
1260	}
1261
1262	if (!status || dma || usb_pipeisoc(pipe)) {
1263		if (dma)
1264			length = dma->actual_len;
1265		else
1266			length = qh->segsize;
1267		qh->offset += length;
1268
1269		if (usb_pipeisoc(pipe)) {
1270#ifndef __UBOOT__
1271			struct usb_iso_packet_descriptor	*d;
1272
1273			d = urb->iso_frame_desc + qh->iso_idx;
1274			d->actual_length = length;
1275			d->status = status;
1276			if (++qh->iso_idx >= urb->number_of_packets) {
1277				done = true;
1278			} else {
1279				d++;
1280				offset = d->offset;
1281				length = d->length;
1282			}
1283#endif
1284		} else if (dma && urb->transfer_buffer_length == qh->offset) {
1285			done = true;
1286		} else {
1287			/* see if we need to send more data, or ZLP */
1288			if (qh->segsize < qh->maxpacket)
1289				done = true;
1290			else if (qh->offset == urb->transfer_buffer_length
1291					&& !(urb->transfer_flags
1292						& URB_ZERO_PACKET))
1293				done = true;
1294			if (!done) {
1295				offset = qh->offset;
1296				length = urb->transfer_buffer_length - offset;
1297				transfer_pending = true;
1298			}
1299		}
1300	}
1301
1302	/* urb->status != -EINPROGRESS means request has been faulted,
1303	 * so we must abort this transfer after cleanup
1304	 */
1305	if (urb->status != -EINPROGRESS) {
1306		done = true;
1307		if (status == 0)
1308			status = urb->status;
1309	}
1310
1311	if (done) {
1312		/* set status */
1313		urb->status = status;
1314		urb->actual_length = qh->offset;
1315		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_OUT);
1316		return;
1317	} else if ((usb_pipeisoc(pipe) || transfer_pending) && dma) {
1318		if (musb_tx_dma_program(musb->dma_controller, hw_ep, qh, urb,
1319				offset, length)) {
1320			if (is_cppi_enabled() || tusb_dma_omap())
1321				musb_h_tx_dma_start(hw_ep);
1322			return;
1323		}
1324	} else	if (tx_csr & MUSB_TXCSR_DMAENAB) {
1325		dev_dbg(musb->controller, "not complete, but DMA enabled?\n");
1326		return;
1327	}
1328
1329	/*
1330	 * PIO: start next packet in this URB.
1331	 *
1332	 * REVISIT: some docs say that when hw_ep->tx_double_buffered,
1333	 * (and presumably, FIFO is not half-full) we should write *two*
1334	 * packets before updating TXCSR; other docs disagree...
1335	 */
1336	if (length > qh->maxpacket)
1337		length = qh->maxpacket;
1338	/* Unmap the buffer so that CPU can use it */
1339	usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
1340	musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
1341	qh->segsize = length;
1342
1343	musb_ep_select(mbase, epnum);
1344	musb_writew(epio, MUSB_TXCSR,
1345			MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
1346}
1347
1348
1349#ifdef CONFIG_USB_INVENTRA_DMA
1350
1351/* Host side RX (IN) using Mentor DMA works as follows:
1352	submit_urb ->
1353		- if queue was empty, ProgramEndpoint
1354		- first IN token is sent out (by setting ReqPkt)
1355	LinuxIsr -> RxReady()
1356	/\	=> first packet is received
1357	|	- Set in mode 0 (DmaEnab, ~ReqPkt)
1358	|		-> DMA Isr (transfer complete) -> RxReady()
1359	|		    - Ack receive (~RxPktRdy), turn off DMA (~DmaEnab)
1360	|		    - if urb not complete, send next IN token (ReqPkt)
1361	|			   |		else complete urb.
1362	|			   |
1363	---------------------------
1364 *
1365 * Nuances of mode 1:
1366 *	For short packets, no ack (+RxPktRdy) is sent automatically
1367 *	(even if AutoClear is ON)
1368 *	For full packets, ack (~RxPktRdy) and next IN token (+ReqPkt) is sent
1369 *	automatically => major problem, as collecting the next packet becomes
1370 *	difficult. Hence mode 1 is not used.
1371 *
1372 * REVISIT
1373 *	All we care about at this driver level is that
1374 *       (a) all URBs terminate with REQPKT cleared and fifo(s) empty;
1375 *       (b) termination conditions are: short RX, or buffer full;
1376 *       (c) fault modes include
1377 *           - iff URB_SHORT_NOT_OK, short RX status is -EREMOTEIO.
1378 *             (and that endpoint's dma queue stops immediately)
1379 *           - overflow (full, PLUS more bytes in the terminal packet)
1380 *
1381 *	So for example, usb-storage sets URB_SHORT_NOT_OK, and would
1382 *	thus be a great candidate for using mode 1 ... for all but the
1383 *	last packet of one URB's transfer.
1384 */
1385
1386#endif
1387
1388/* Schedule next QH from musb->in_bulk and move the current qh to
1389 * the end; avoids starvation for other endpoints.
1390 */
1391static void musb_bulk_rx_nak_timeout(struct musb *musb, struct musb_hw_ep *ep)
1392{
1393	struct dma_channel	*dma;
1394	struct urb		*urb;
1395	void __iomem		*mbase = musb->mregs;
1396	void __iomem		*epio = ep->regs;
1397	struct musb_qh		*cur_qh, *next_qh;
1398	u16			rx_csr;
1399
1400	musb_ep_select(mbase, ep->epnum);
1401	dma = is_dma_capable() ? ep->rx_channel : NULL;
1402
1403	/* clear nak timeout bit */
1404	rx_csr = musb_readw(epio, MUSB_RXCSR);
1405	rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1406	rx_csr &= ~MUSB_RXCSR_DATAERROR;
1407	musb_writew(epio, MUSB_RXCSR, rx_csr);
1408
1409	cur_qh = first_qh(&musb->in_bulk);
1410	if (cur_qh) {
1411		urb = next_urb(cur_qh);
1412		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1413			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1414			musb->dma_controller->channel_abort(dma);
1415			urb->actual_length += dma->actual_len;
1416			dma->actual_len = 0L;
1417		}
1418		musb_save_toggle(cur_qh, 1, urb);
1419
1420		/* move cur_qh to end of queue */
1421		list_move_tail(&cur_qh->ring, &musb->in_bulk);
1422
1423		/* get the next qh from musb->in_bulk */
1424		next_qh = first_qh(&musb->in_bulk);
1425
1426		/* set rx_reinit and schedule the next qh */
1427		ep->rx_reinit = 1;
1428		musb_start_urb(musb, 1, next_qh);
1429	}
1430}
1431
1432/*
1433 * Service an RX interrupt for the given IN endpoint; docs cover bulk, iso,
1434 * and high-bandwidth IN transfer cases.
1435 */
1436void musb_host_rx(struct musb *musb, u8 epnum)
1437{
1438	struct urb		*urb;
1439	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1440	void __iomem		*epio = hw_ep->regs;
1441	struct musb_qh		*qh = hw_ep->in_qh;
1442	size_t			xfer_len;
1443	void __iomem		*mbase = musb->mregs;
1444	int			pipe;
1445	u16			rx_csr, val;
1446	bool			iso_err = false;
1447	bool			done = false;
1448	u32			status;
1449	struct dma_channel	*dma;
1450
1451	musb_ep_select(mbase, epnum);
1452
1453	urb = next_urb(qh);
1454	dma = is_dma_capable() ? hw_ep->rx_channel : NULL;
1455	status = 0;
1456	xfer_len = 0;
1457
1458	rx_csr = musb_readw(epio, MUSB_RXCSR);
1459	val = rx_csr;
1460
1461	if (unlikely(!urb)) {
1462		/* REVISIT -- THIS SHOULD NEVER HAPPEN ... but, at least
1463		 * usbtest #11 (unlinks) triggers it regularly, sometimes
1464		 * with fifo full.  (Only with DMA??)
1465		 */
1466		dev_dbg(musb->controller, "BOGUS RX%d ready, csr %04x, count %d\n", epnum, val,
1467			musb_readw(epio, MUSB_RXCOUNT));
1468		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1469		return;
1470	}
1471
1472	pipe = urb->pipe;
1473
1474	dev_dbg(musb->controller, "<== hw %d rxcsr %04x, urb actual %d (+dma %zu)\n",
1475		epnum, rx_csr, urb->actual_length,
1476		dma ? dma->actual_len : 0);
1477
1478	/* check for errors, concurrent stall & unlink is not really
1479	 * handled yet! */
1480	if (rx_csr & MUSB_RXCSR_H_RXSTALL) {
1481		dev_dbg(musb->controller, "RX end %d STALL\n", epnum);
1482
1483		/* stall; record URB status */
1484		status = -EPIPE;
1485
1486	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
1487		dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
1488
1489		status = -EPROTO;
1490		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1491
1492	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
1493
1494		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
1495			dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
1496
1497			/* NOTE: NAKing is *NOT* an error, so we want to
1498			 * continue.  Except ... if there's a request for
1499			 * another QH, use that instead of starving it.
1500			 *
1501			 * Devices like Ethernet and serial adapters keep
1502			 * reads posted at all times, which will starve
1503			 * other devices without this logic.
1504			 */
1505			if (usb_pipebulk(urb->pipe)
1506					&& qh->mux == 1
1507					&& !list_is_singular(&musb->in_bulk)) {
1508				musb_bulk_rx_nak_timeout(musb, hw_ep);
1509				return;
1510			}
1511			musb_ep_select(mbase, epnum);
1512			rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1513			rx_csr &= ~MUSB_RXCSR_DATAERROR;
1514			musb_writew(epio, MUSB_RXCSR, rx_csr);
1515
1516			goto finish;
1517		} else {
1518			dev_dbg(musb->controller, "RX end %d ISO data error\n", epnum);
1519			/* packet error reported later */
1520			iso_err = true;
1521		}
1522	} else if (rx_csr & MUSB_RXCSR_INCOMPRX) {
1523		dev_dbg(musb->controller, "end %d high bandwidth incomplete ISO packet RX\n",
1524				epnum);
1525		status = -EPROTO;
1526	}
1527
1528	/* faults abort the transfer */
1529	if (status) {
1530		/* clean up dma and collect transfer count */
1531		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1532			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1533			(void) musb->dma_controller->channel_abort(dma);
1534			xfer_len = dma->actual_len;
1535		}
1536		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1537		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1538		done = true;
1539		goto finish;
1540	}
1541
1542	if (unlikely(dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY)) {
1543		/* SHOULD NEVER HAPPEN ... but at least DaVinci has done it */
1544		ERR("RX%d dma busy, csr %04x\n", epnum, rx_csr);
1545		goto finish;
1546	}
1547
1548	/* thorough shutdown for now ... given more precise fault handling
1549	 * and better queueing support, we might keep a DMA pipeline going
1550	 * while processing this irq for earlier completions.
1551	 */
1552
1553	/* FIXME this is _way_ too much in-line logic for Mentor DMA */
1554
1555#ifndef CONFIG_USB_INVENTRA_DMA
1556	if (rx_csr & MUSB_RXCSR_H_REQPKT)  {
1557		/* REVISIT this happened for a while on some short reads...
1558		 * the cleanup still needs investigation... looks bad...
1559		 * and also duplicates dma cleanup code above ... plus,
1560		 * shouldn't this be the "half full" double buffer case?
1561		 */
1562		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1563			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1564			(void) musb->dma_controller->channel_abort(dma);
1565			xfer_len = dma->actual_len;
1566			done = true;
1567		}
1568
1569		dev_dbg(musb->controller, "RXCSR%d %04x, reqpkt, len %zu%s\n", epnum, rx_csr,
1570				xfer_len, dma ? ", dma" : "");
1571		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
1572
1573		musb_ep_select(mbase, epnum);
1574		musb_writew(epio, MUSB_RXCSR,
1575				MUSB_RXCSR_H_WZC_BITS | rx_csr);
1576	}
1577#endif
1578	if (dma && (rx_csr & MUSB_RXCSR_DMAENAB)) {
1579		xfer_len = dma->actual_len;
1580
1581		val &= ~(MUSB_RXCSR_DMAENAB
1582			| MUSB_RXCSR_H_AUTOREQ
1583			| MUSB_RXCSR_AUTOCLEAR
1584			| MUSB_RXCSR_RXPKTRDY);
1585		musb_writew(hw_ep->regs, MUSB_RXCSR, val);
1586
1587#ifdef CONFIG_USB_INVENTRA_DMA
1588		if (usb_pipeisoc(pipe)) {
1589			struct usb_iso_packet_descriptor *d;
1590
1591			d = urb->iso_frame_desc + qh->iso_idx;
1592			d->actual_length = xfer_len;
1593
1594			/* even if there was an error, we did the dma
1595			 * for iso_frame_desc->length
1596			 */
1597			if (d->status != -EILSEQ && d->status != -EOVERFLOW)
1598				d->status = 0;
1599
1600			if (++qh->iso_idx >= urb->number_of_packets)
1601				done = true;
1602			else
1603				done = false;
1604
1605		} else  {
1606		/* done if urb buffer is full or short packet is recd */
1607		done = (urb->actual_length + xfer_len >=
1608				urb->transfer_buffer_length
1609			|| dma->actual_len < qh->maxpacket);
1610		}
1611
1612		/* send IN token for next packet, without AUTOREQ */
1613		if (!done) {
1614			val |= MUSB_RXCSR_H_REQPKT;
1615			musb_writew(epio, MUSB_RXCSR,
1616				MUSB_RXCSR_H_WZC_BITS | val);
1617		}
1618
1619		dev_dbg(musb->controller, "ep %d dma %s, rxcsr %04x, rxcount %d\n", epnum,
1620			done ? "off" : "reset",
1621			musb_readw(epio, MUSB_RXCSR),
1622			musb_readw(epio, MUSB_RXCOUNT));
1623#else
1624		done = true;
1625#endif
1626	} else if (urb->status == -EINPROGRESS) {
1627		/* if no errors, be sure a packet is ready for unloading */
1628		if (unlikely(!(rx_csr & MUSB_RXCSR_RXPKTRDY))) {
1629			status = -EPROTO;
1630			ERR("Rx interrupt with no errors or packet!\n");
1631
1632			/* FIXME this is another "SHOULD NEVER HAPPEN" */
1633
1634/* SCRUB (RX) */
1635			/* do the proper sequence to abort the transfer */
1636			musb_ep_select(mbase, epnum);
1637			val &= ~MUSB_RXCSR_H_REQPKT;
1638			musb_writew(epio, MUSB_RXCSR, val);
1639			goto finish;
1640		}
1641
1642		/* we are expecting IN packets */
1643#ifdef CONFIG_USB_INVENTRA_DMA
1644		if (dma) {
1645			struct dma_controller	*c;
1646			u16			rx_count;
1647			int			ret, length;
1648			dma_addr_t		buf;
1649
1650			rx_count = musb_readw(epio, MUSB_RXCOUNT);
1651
1652			dev_dbg(musb->controller, "RX%d count %d, buffer 0x%x len %d/%d\n",
1653					epnum, rx_count,
1654					urb->transfer_dma
1655						+ urb->actual_length,
1656					qh->offset,
1657					urb->transfer_buffer_length);
1658
1659			c = musb->dma_controller;
1660
1661			if (usb_pipeisoc(pipe)) {
1662				int d_status = 0;
1663				struct usb_iso_packet_descriptor *d;
1664
1665				d = urb->iso_frame_desc + qh->iso_idx;
1666
1667				if (iso_err) {
1668					d_status = -EILSEQ;
1669					urb->error_count++;
1670				}
1671				if (rx_count > d->length) {
1672					if (d_status == 0) {
1673						d_status = -EOVERFLOW;
1674						urb->error_count++;
1675					}
1676					dev_dbg(musb->controller, "** OVERFLOW %d into %d\n",\
1677					    rx_count, d->length);
1678
1679					length = d->length;
1680				} else
1681					length = rx_count;
1682				d->status = d_status;
1683				buf = urb->transfer_dma + d->offset;
1684			} else {
1685				length = rx_count;
1686				buf = urb->transfer_dma +
1687						urb->actual_length;
1688			}
1689
1690			dma->desired_mode = 0;
1691#ifdef USE_MODE1
1692			/* because of the issue below, mode 1 will
1693			 * only rarely behave with correct semantics.
1694			 */
1695			if ((urb->transfer_flags &
1696						URB_SHORT_NOT_OK)
1697				&& (urb->transfer_buffer_length -
1698						urb->actual_length)
1699					> qh->maxpacket)
1700				dma->desired_mode = 1;
1701			if (rx_count < hw_ep->max_packet_sz_rx) {
1702				length = rx_count;
1703				dma->desired_mode = 0;
1704			} else {
1705				length = urb->transfer_buffer_length;
1706			}
1707#endif
1708
1709/* Disadvantage of using mode 1:
1710 *	It's basically usable only for mass storage class; essentially all
1711 *	other protocols also terminate transfers on short packets.
1712 *
1713 * Details:
1714 *	An extra IN token is sent at the end of the transfer (due to AUTOREQ)
1715 *	If you try to use mode 1 for (transfer_buffer_length - 512), and try
1716 *	to use the extra IN token to grab the last packet using mode 0, then
1717 *	the problem is that you cannot be sure when the device will send the
1718 *	last packet and RxPktRdy set. Sometimes the packet is recd too soon
1719 *	such that it gets lost when RxCSR is re-set at the end of the mode 1
1720 *	transfer, while sometimes it is recd just a little late so that if you
1721 *	try to configure for mode 0 soon after the mode 1 transfer is
1722 *	completed, you will find rxcount 0. Okay, so you might think why not
1723 *	wait for an interrupt when the pkt is recd. Well, you won't get any!
1724 */
1725
1726			val = musb_readw(epio, MUSB_RXCSR);
1727			val &= ~MUSB_RXCSR_H_REQPKT;
1728
1729			if (dma->desired_mode == 0)
1730				val &= ~MUSB_RXCSR_H_AUTOREQ;
1731			else
1732				val |= MUSB_RXCSR_H_AUTOREQ;
1733			val |= MUSB_RXCSR_DMAENAB;
1734
1735			/* autoclear shouldn't be set in high bandwidth */
1736			if (qh->hb_mult == 1)
1737				val |= MUSB_RXCSR_AUTOCLEAR;
1738
1739			musb_writew(epio, MUSB_RXCSR,
1740				MUSB_RXCSR_H_WZC_BITS | val);
1741
1742			/* REVISIT if when actual_length != 0,
1743			 * transfer_buffer_length needs to be
1744			 * adjusted first...
1745			 */
1746			ret = c->channel_program(
1747				dma, qh->maxpacket,
1748				dma->desired_mode, buf, length);
1749
1750			if (!ret) {
1751				c->channel_release(dma);
1752				hw_ep->rx_channel = NULL;
1753				dma = NULL;
1754				val = musb_readw(epio, MUSB_RXCSR);
1755				val &= ~(MUSB_RXCSR_DMAENAB
1756					| MUSB_RXCSR_H_AUTOREQ
1757					| MUSB_RXCSR_AUTOCLEAR);
1758				musb_writew(epio, MUSB_RXCSR, val);
1759			}
1760		}
1761#endif	/* Mentor DMA */
1762
1763		if (!dma) {
1764			/* Unmap the buffer so that CPU can use it */
1765			usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
1766			done = musb_host_packet_rx(musb, urb,
1767					epnum, iso_err);
1768			dev_dbg(musb->controller, "read %spacket\n", done ? "last " : "");
1769		}
1770	}
1771
1772finish:
1773	urb->actual_length += xfer_len;
1774	qh->offset += xfer_len;
1775	if (done) {
1776		if (urb->status == -EINPROGRESS)
1777			urb->status = status;
1778		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
1779	}
1780}
1781
1782/* schedule nodes correspond to peripheral endpoints, like an OHCI QH.
1783 * the software schedule associates multiple such nodes with a given
1784 * host side hardware endpoint + direction; scheduling may activate
1785 * that hardware endpoint.
1786 */
1787static int musb_schedule(
1788	struct musb		*musb,
1789	struct musb_qh		*qh,
1790	int			is_in)
1791{
1792	int			idle;
1793	int			best_diff;
1794	int			best_end, epnum;
1795	struct musb_hw_ep	*hw_ep = NULL;
1796	struct list_head	*head = NULL;
1797	u8			toggle;
1798	u8			txtype;
1799	struct urb		*urb = next_urb(qh);
1800
1801	/* use fixed hardware for control and bulk */
1802	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
1803		head = &musb->control;
1804		hw_ep = musb->control_ep;
1805		goto success;
1806	}
1807
1808	/* else, periodic transfers get muxed to other endpoints */
1809
1810	/*
1811	 * We know this qh hasn't been scheduled, so all we need to do
1812	 * is choose which hardware endpoint to put it on ...
1813	 *
1814	 * REVISIT what we really want here is a regular schedule tree
1815	 * like e.g. OHCI uses.
1816	 */
1817	best_diff = 4096;
1818	best_end = -1;
1819
1820	for (epnum = 1, hw_ep = musb->endpoints + 1;
1821			epnum < musb->nr_endpoints;
1822			epnum++, hw_ep++) {
1823		int	diff;
1824
1825		if (musb_ep_get_qh(hw_ep, is_in) != NULL)
1826			continue;
1827
1828		if (hw_ep == musb->bulk_ep)
1829			continue;
1830
1831		if (is_in)
1832			diff = hw_ep->max_packet_sz_rx;
1833		else
1834			diff = hw_ep->max_packet_sz_tx;
1835		diff -= (qh->maxpacket * qh->hb_mult);
1836
1837		if (diff >= 0 && best_diff > diff) {
1838
1839			/*
1840			 * Mentor controller has a bug in that if we schedule
1841			 * a BULK Tx transfer on an endpoint that had earlier
1842			 * handled ISOC then the BULK transfer has to start on
1843			 * a zero toggle.  If the BULK transfer starts on a 1
1844			 * toggle then this transfer will fail as the mentor
1845			 * controller starts the Bulk transfer on a 0 toggle
1846			 * irrespective of the programming of the toggle bits
1847			 * in the TXCSR register.  Check for this condition
1848			 * while allocating the EP for a Tx Bulk transfer.  If
1849			 * so skip this EP.
1850			 */
1851			hw_ep = musb->endpoints + epnum;
1852			toggle = usb_gettoggle(urb->dev, qh->epnum, !is_in);
1853			txtype = (musb_readb(hw_ep->regs, MUSB_TXTYPE)
1854					>> 4) & 0x3;
1855			if (!is_in && (qh->type == USB_ENDPOINT_XFER_BULK) &&
1856				toggle && (txtype == USB_ENDPOINT_XFER_ISOC))
1857				continue;
1858
1859			best_diff = diff;
1860			best_end = epnum;
1861		}
1862	}
1863	/* use bulk reserved ep1 if no other ep is free */
1864	if (best_end < 0 && qh->type == USB_ENDPOINT_XFER_BULK) {
1865		hw_ep = musb->bulk_ep;
1866		if (is_in)
1867			head = &musb->in_bulk;
1868		else
1869			head = &musb->out_bulk;
1870
1871		/* Enable bulk RX NAK timeout scheme when bulk requests are
1872		 * multiplexed.  This scheme doen't work in high speed to full
1873		 * speed scenario as NAK interrupts are not coming from a
1874		 * full speed device connected to a high speed device.
1875		 * NAK timeout interval is 8 (128 uframe or 16ms) for HS and
1876		 * 4 (8 frame or 8ms) for FS device.
1877		 */
1878		if (is_in && qh->dev)
1879			qh->intv_reg =
1880				(USB_SPEED_HIGH == qh->dev->speed) ? 8 : 4;
1881		goto success;
1882	} else if (best_end < 0) {
1883		return -ENOSPC;
1884	}
1885
1886	idle = 1;
1887	qh->mux = 0;
1888	hw_ep = musb->endpoints + best_end;
1889	dev_dbg(musb->controller, "qh %p periodic slot %d\n", qh, best_end);
1890success:
1891	if (head) {
1892		idle = list_empty(head);
1893		list_add_tail(&qh->ring, head);
1894		qh->mux = 1;
1895	}
1896	qh->hw_ep = hw_ep;
1897	qh->hep->hcpriv = qh;
1898	if (idle)
1899		musb_start_urb(musb, is_in, qh);
1900	return 0;
1901}
1902
1903#ifdef __UBOOT__
1904/* check if transaction translator is needed for device */
1905static int tt_needed(struct musb *musb, struct usb_device *dev)
1906{
1907	if ((musb_readb(musb->mregs, MUSB_POWER) & MUSB_POWER_HSMODE) &&
1908			(dev->speed < USB_SPEED_HIGH))
1909		return 1;
1910	return 0;
1911}
1912#endif
1913
1914#ifndef __UBOOT__
1915static int musb_urb_enqueue(
1916#else
1917int musb_urb_enqueue(
1918#endif
1919	struct usb_hcd			*hcd,
1920	struct urb			*urb,
1921	gfp_t				mem_flags)
1922{
1923	unsigned long			flags;
1924	struct musb			*musb = hcd_to_musb(hcd);
1925	struct usb_host_endpoint	*hep = urb->ep;
1926	struct musb_qh			*qh;
1927	struct usb_endpoint_descriptor	*epd = &hep->desc;
1928	int				ret;
1929	unsigned			type_reg;
1930	unsigned			interval;
1931
1932	/* host role must be active */
1933	if (!is_host_active(musb) || !musb->is_active)
1934		return -ENODEV;
1935
1936	spin_lock_irqsave(&musb->lock, flags);
1937	ret = usb_hcd_link_urb_to_ep(hcd, urb);
1938	qh = ret ? NULL : hep->hcpriv;
1939	if (qh)
1940		urb->hcpriv = qh;
1941	spin_unlock_irqrestore(&musb->lock, flags);
1942
1943	/* DMA mapping was already done, if needed, and this urb is on
1944	 * hep->urb_list now ... so we're done, unless hep wasn't yet
1945	 * scheduled onto a live qh.
1946	 *
1947	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets
1948	 * disabled, testing for empty qh->ring and avoiding qh setup costs
1949	 * except for the first urb queued after a config change.
1950	 */
1951	if (qh || ret)
1952		return ret;
1953
1954	/* Allocate and initialize qh, minimizing the work done each time
1955	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.
1956	 *
1957	 * REVISIT consider a dedicated qh kmem_cache, so it's harder
1958	 * for bugs in other kernel code to break this driver...
1959	 */
1960	qh = kzalloc(sizeof *qh, mem_flags);
1961	if (!qh) {
1962		spin_lock_irqsave(&musb->lock, flags);
1963		usb_hcd_unlink_urb_from_ep(hcd, urb);
1964		spin_unlock_irqrestore(&musb->lock, flags);
1965		return -ENOMEM;
1966	}
1967
1968	qh->hep = hep;
1969	qh->dev = urb->dev;
1970	INIT_LIST_HEAD(&qh->ring);
1971	qh->is_ready = 1;
1972
1973	qh->maxpacket = usb_endpoint_maxp(epd);
1974	qh->type = usb_endpoint_type(epd);
1975
1976	/* Bits 11 & 12 of wMaxPacketSize encode high bandwidth multiplier.
1977	 * Some musb cores don't support high bandwidth ISO transfers; and
1978	 * we don't (yet!) support high bandwidth interrupt transfers.
1979	 */
1980	qh->hb_mult = 1 + ((qh->maxpacket >> 11) & 0x03);
1981	if (qh->hb_mult > 1) {
1982		int ok = (qh->type == USB_ENDPOINT_XFER_ISOC);
1983
1984		if (ok)
1985			ok = (usb_pipein(urb->pipe) && musb->hb_iso_rx)
1986				|| (usb_pipeout(urb->pipe) && musb->hb_iso_tx);
1987		if (!ok) {
1988			ret = -EMSGSIZE;
1989			goto done;
1990		}
1991		qh->maxpacket &= 0x7ff;
1992	}
1993
1994	qh->epnum = usb_endpoint_num(epd);
1995
1996	/* NOTE: urb->dev->devnum is wrong during SET_ADDRESS */
1997	qh->addr_reg = (u8) usb_pipedevice(urb->pipe);
1998
1999	/* precompute rxtype/txtype/type0 register */
2000	type_reg = (qh->type << 4) | qh->epnum;
2001	switch (urb->dev->speed) {
2002	case USB_SPEED_LOW:
2003		type_reg |= 0xc0;
2004		break;
2005	case USB_SPEED_FULL:
2006		type_reg |= 0x80;
2007		break;
2008	default:
2009		type_reg |= 0x40;
2010	}
2011	qh->type_reg = type_reg;
2012
2013	/* Precompute RXINTERVAL/TXINTERVAL register */
2014	switch (qh->type) {
2015	case USB_ENDPOINT_XFER_INT:
2016		/*
2017		 * Full/low speeds use the  linear encoding,
2018		 * high speed uses the logarithmic encoding.
2019		 */
2020		if (urb->dev->speed <= USB_SPEED_FULL) {
2021			interval = max_t(u8, epd->bInterval, 1);
2022			break;
2023		}
2024		/* FALLTHROUGH */
2025	case USB_ENDPOINT_XFER_ISOC:
2026		/* ISO always uses logarithmic encoding */
2027		interval = min_t(u8, epd->bInterval, 16);
2028		break;
2029	default:
2030		/* REVISIT we actually want to use NAK limits, hinting to the
2031		 * transfer scheduling logic to try some other qh, e.g. try
2032		 * for 2 msec first:
2033		 *
2034		 * interval = (USB_SPEED_HIGH == urb->dev->speed) ? 16 : 2;
2035		 *
2036		 * The downside of disabling this is that transfer scheduling
2037		 * gets VERY unfair for nonperiodic transfers; a misbehaving
2038		 * peripheral could make that hurt.  That's perfectly normal
2039		 * for reads from network or serial adapters ... so we have
2040		 * partial NAKlimit support for bulk RX.
2041		 *
2042		 * The upside of disabling it is simpler transfer scheduling.
2043		 */
2044		interval = 0;
2045	}
2046	qh->intv_reg = interval;
2047
2048	/* precompute addressing for external hub/tt ports */
2049	if (musb->is_multipoint) {
2050#ifndef __UBOOT__
2051		struct usb_device	*parent = urb->dev->parent;
2052#else
2053		struct usb_device	*parent = usb_dev_get_parent(urb->dev);
2054#endif
2055
2056#ifndef __UBOOT__
2057		if (parent != hcd->self.root_hub) {
2058#else
2059		if (parent) {
2060#endif
2061			qh->h_addr_reg = (u8) parent->devnum;
2062
2063#ifndef __UBOOT__
2064			/* set up tt info if needed */
2065			if (urb->dev->tt) {
2066				qh->h_port_reg = (u8) urb->dev->ttport;
2067				if (urb->dev->tt->hub)
2068					qh->h_addr_reg =
2069						(u8) urb->dev->tt->hub->devnum;
2070				if (urb->dev->tt->multi)
2071					qh->h_addr_reg |= 0x80;
2072			}
2073#else
2074			if (tt_needed(musb, urb->dev)) {
2075				uint8_t portnr = 0;
2076				uint8_t hubaddr = 0;
2077				usb_find_usb2_hub_address_port(urb->dev,
2078							       &hubaddr,
2079							       &portnr);
2080				qh->h_addr_reg = hubaddr;
2081				qh->h_port_reg = portnr;
2082			}
2083#endif
2084		}
2085	}
2086
2087	/* invariant: hep->hcpriv is null OR the qh that's already scheduled.
2088	 * until we get real dma queues (with an entry for each urb/buffer),
2089	 * we only have work to do in the former case.
2090	 */
2091	spin_lock_irqsave(&musb->lock, flags);
2092	if (hep->hcpriv) {
2093		/* some concurrent activity submitted another urb to hep...
2094		 * odd, rare, error prone, but legal.
2095		 */
2096		kfree(qh);
2097		qh = NULL;
2098		ret = 0;
2099	} else
2100		ret = musb_schedule(musb, qh,
2101				epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK);
2102
2103	if (ret == 0) {
2104		urb->hcpriv = qh;
2105		/* FIXME set urb->start_frame for iso/intr, it's tested in
2106		 * musb_start_urb(), but otherwise only konicawc cares ...
2107		 */
2108	}
2109	spin_unlock_irqrestore(&musb->lock, flags);
2110
2111done:
2112	if (ret != 0) {
2113		spin_lock_irqsave(&musb->lock, flags);
2114		usb_hcd_unlink_urb_from_ep(hcd, urb);
2115		spin_unlock_irqrestore(&musb->lock, flags);
2116		kfree(qh);
2117	}
2118	return ret;
2119}
2120
2121/*
2122 * abort a transfer that's at the head of a hardware queue.
2123 * called with controller locked, irqs blocked
2124 * that hardware queue advances to the next transfer, unless prevented
2125 */
2126static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
2127{
2128	struct musb_hw_ep	*ep = qh->hw_ep;
2129	struct musb		*musb = ep->musb;
2130	void __iomem		*epio = ep->regs;
2131	unsigned		hw_end = ep->epnum;
2132	void __iomem		*regs = ep->musb->mregs;
2133	int			is_in = usb_pipein(urb->pipe);
2134	int			status = 0;
2135	u16			csr;
2136
2137	musb_ep_select(regs, hw_end);
2138
2139	if (is_dma_capable()) {
2140		struct dma_channel	*dma;
2141
2142		dma = is_in ? ep->rx_channel : ep->tx_channel;
2143		if (dma) {
2144			status = ep->musb->dma_controller->channel_abort(dma);
2145			dev_dbg(musb->controller,
2146				"abort %cX%d DMA for urb %p --> %d\n",
2147				is_in ? 'R' : 'T', ep->epnum,
2148				urb, status);
2149			urb->actual_length += dma->actual_len;
2150		}
2151	}
2152
2153	/* turn off DMA requests, discard state, stop polling ... */
2154	if (ep->epnum && is_in) {
2155		/* giveback saves bulk toggle */
2156		csr = musb_h_flush_rxfifo(ep, 0);
2157
2158		/* REVISIT we still get an irq; should likely clear the
2159		 * endpoint's irq status here to avoid bogus irqs.
2160		 * clearing that status is platform-specific...
2161		 */
2162	} else if (ep->epnum) {
2163		musb_h_tx_flush_fifo(ep);
2164		csr = musb_readw(epio, MUSB_TXCSR);
2165		csr &= ~(MUSB_TXCSR_AUTOSET
2166			| MUSB_TXCSR_DMAENAB
2167			| MUSB_TXCSR_H_RXSTALL
2168			| MUSB_TXCSR_H_NAKTIMEOUT
2169			| MUSB_TXCSR_H_ERROR
2170			| MUSB_TXCSR_TXPKTRDY);
2171		musb_writew(epio, MUSB_TXCSR, csr);
2172		/* REVISIT may need to clear FLUSHFIFO ... */
2173		musb_writew(epio, MUSB_TXCSR, csr);
2174		/* flush cpu writebuffer */
2175		csr = musb_readw(epio, MUSB_TXCSR);
2176	} else  {
2177		musb_h_ep0_flush_fifo(ep);
2178	}
2179	if (status == 0)
2180		musb_advance_schedule(ep->musb, urb, ep, is_in);
2181	return status;
2182}
2183
2184#ifndef __UBOOT__
2185static int musb_urb_dequeue(
2186#else
2187int musb_urb_dequeue(
2188#endif
2189	struct usb_hcd *hcd,
2190	struct urb *urb,
2191	int status)
2192{
2193	struct musb		*musb = hcd_to_musb(hcd);
2194	struct musb_qh		*qh;
2195	unsigned long		flags;
2196	int			is_in  = usb_pipein(urb->pipe);
2197	int			ret;
2198
2199	dev_dbg(musb->controller, "urb=%p, dev%d ep%d%s\n", urb,
2200			usb_pipedevice(urb->pipe),
2201			usb_pipeendpoint(urb->pipe),
2202			is_in ? "in" : "out");
2203
2204	spin_lock_irqsave(&musb->lock, flags);
2205	ret = usb_hcd_check_unlink_urb(hcd, urb, status);
2206	if (ret)
2207		goto done;
2208
2209	qh = urb->hcpriv;
2210	if (!qh)
2211		goto done;
2212
2213	/*
2214	 * Any URB not actively programmed into endpoint hardware can be
2215	 * immediately given back; that's any URB not at the head of an
2216	 * endpoint queue, unless someday we get real DMA queues.  And even
2217	 * if it's at the head, it might not be known to the hardware...
2218	 *
2219	 * Otherwise abort current transfer, pending DMA, etc.; urb->status
2220	 * has already been updated.  This is a synchronous abort; it'd be
2221	 * OK to hold off until after some IRQ, though.
2222	 *
2223	 * NOTE: qh is invalid unless !list_empty(&hep->urb_list)
2224	 */
2225	if (!qh->is_ready
2226			|| urb->urb_list.prev != &qh->hep->urb_list
2227			|| musb_ep_get_qh(qh->hw_ep, is_in) != qh) {
2228		int	ready = qh->is_ready;
2229
2230		qh->is_ready = 0;
2231		musb_giveback(musb, urb, 0);
2232		qh->is_ready = ready;
2233
2234		/* If nothing else (usually musb_giveback) is using it
2235		 * and its URB list has emptied, recycle this qh.
2236		 */
2237		if (ready && list_empty(&qh->hep->urb_list)) {
2238			qh->hep->hcpriv = NULL;
2239			list_del(&qh->ring);
2240			kfree(qh);
2241		}
2242	} else
2243		ret = musb_cleanup_urb(urb, qh);
2244done:
2245	spin_unlock_irqrestore(&musb->lock, flags);
2246	return ret;
2247}
2248
2249#ifndef __UBOOT__
2250/* disable an endpoint */
2251static void
2252musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
2253{
2254	u8			is_in = hep->desc.bEndpointAddress & USB_DIR_IN;
2255	unsigned long		flags;
2256	struct musb		*musb = hcd_to_musb(hcd);
2257	struct musb_qh		*qh;
2258	struct urb		*urb;
2259
2260	spin_lock_irqsave(&musb->lock, flags);
2261
2262	qh = hep->hcpriv;
2263	if (qh == NULL)
2264		goto exit;
2265
2266	/* NOTE: qh is invalid unless !list_empty(&hep->urb_list) */
2267
2268	/* Kick the first URB off the hardware, if needed */
2269	qh->is_ready = 0;
2270	if (musb_ep_get_qh(qh->hw_ep, is_in) == qh) {
2271		urb = next_urb(qh);
2272
2273		/* make software (then hardware) stop ASAP */
2274		if (!urb->unlinked)
2275			urb->status = -ESHUTDOWN;
2276
2277		/* cleanup */
2278		musb_cleanup_urb(urb, qh);
2279
2280		/* Then nuke all the others ... and advance the
2281		 * queue on hw_ep (e.g. bulk ring) when we're done.
2282		 */
2283		while (!list_empty(&hep->urb_list)) {
2284			urb = next_urb(qh);
2285			urb->status = -ESHUTDOWN;
2286			musb_advance_schedule(musb, urb, qh->hw_ep, is_in);
2287		}
2288	} else {
2289		/* Just empty the queue; the hardware is busy with
2290		 * other transfers, and since !qh->is_ready nothing
2291		 * will activate any of these as it advances.
2292		 */
2293		while (!list_empty(&hep->urb_list))
2294			musb_giveback(musb, next_urb(qh), -ESHUTDOWN);
2295
2296		hep->hcpriv = NULL;
2297		list_del(&qh->ring);
2298		kfree(qh);
2299	}
2300exit:
2301	spin_unlock_irqrestore(&musb->lock, flags);
2302}
2303
2304static int musb_h_get_frame_number(struct usb_hcd *hcd)
2305{
2306	struct musb	*musb = hcd_to_musb(hcd);
2307
2308	return musb_readw(musb->mregs, MUSB_FRAME);
2309}
2310
2311static int musb_h_start(struct usb_hcd *hcd)
2312{
2313	struct musb	*musb = hcd_to_musb(hcd);
2314
2315	/* NOTE: musb_start() is called when the hub driver turns
2316	 * on port power, or when (OTG) peripheral starts.
2317	 */
2318	hcd->state = HC_STATE_RUNNING;
2319	musb->port1_status = 0;
2320	return 0;
2321}
2322
2323static void musb_h_stop(struct usb_hcd *hcd)
2324{
2325	musb_stop(hcd_to_musb(hcd));
2326	hcd->state = HC_STATE_HALT;
2327}
2328
2329static int musb_bus_suspend(struct usb_hcd *hcd)
2330{
2331	struct musb	*musb = hcd_to_musb(hcd);
2332	u8		devctl;
2333
2334	if (!is_host_active(musb))
2335		return 0;
2336
2337	switch (musb->xceiv->state) {
2338	case OTG_STATE_A_SUSPEND:
2339		return 0;
2340	case OTG_STATE_A_WAIT_VRISE:
2341		/* ID could be grounded even if there's no device
2342		 * on the other end of the cable.  NOTE that the
2343		 * A_WAIT_VRISE timers are messy with MUSB...
2344		 */
2345		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2346		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2347			musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2348		break;
2349	default:
2350		break;
2351	}
2352
2353	if (musb->is_active) {
2354		WARNING("trying to suspend as %s while active\n",
2355				otg_state_string(musb->xceiv->state));
2356		return -EBUSY;
2357	} else
2358		return 0;
2359}
2360
2361static int musb_bus_resume(struct usb_hcd *hcd)
2362{
2363	/* resuming child port does the work */
2364	return 0;
2365}
2366
2367const struct hc_driver musb_hc_driver = {
2368	.description		= "musb-hcd",
2369	.product_desc		= "MUSB HDRC host driver",
2370	.hcd_priv_size		= sizeof(struct musb),
2371	.flags			= HCD_USB2 | HCD_MEMORY,
2372
2373	/* not using irq handler or reset hooks from usbcore, since
2374	 * those must be shared with peripheral code for OTG configs
2375	 */
2376
2377	.start			= musb_h_start,
2378	.stop			= musb_h_stop,
2379
2380	.get_frame_number	= musb_h_get_frame_number,
2381
2382	.urb_enqueue		= musb_urb_enqueue,
2383	.urb_dequeue		= musb_urb_dequeue,
2384	.endpoint_disable	= musb_h_disable,
2385
2386	.hub_status_data	= musb_hub_status_data,
2387	.hub_control		= musb_hub_control,
2388	.bus_suspend		= musb_bus_suspend,
2389	.bus_resume		= musb_bus_resume,
2390	/* .start_port_reset	= NULL, */
2391	/* .hub_irq_enable	= NULL, */
2392};
2393#endif
2394