musb_gadget_ep0.c revision 550a7375fe720924241f0eb76e4a5c1a3eb8c32f
1/*
2 * MUSB OTG peripheral driver ep0 handling
3 *
4 * Copyright 2005 Mentor Graphics Corporation
5 * Copyright (C) 2005-2006 by Texas Instruments
6 * Copyright (C) 2006-2007 Nokia Corporation
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * version 2 as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20 * 02110-1301 USA
21 *
22 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
25 * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
28 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
29 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 *
33 */
34
35#include <linux/kernel.h>
36#include <linux/list.h>
37#include <linux/timer.h>
38#include <linux/spinlock.h>
39#include <linux/init.h>
40#include <linux/device.h>
41#include <linux/interrupt.h>
42
43#include "musb_core.h"
44
45/* ep0 is always musb->endpoints[0].ep_in */
46#define	next_ep0_request(musb)	next_in_request(&(musb)->endpoints[0])
47
48/*
49 * locking note:  we use only the controller lock, for simpler correctness.
50 * It's always held with IRQs blocked.
51 *
52 * It protects the ep0 request queue as well as ep0_state, not just the
53 * controller and indexed registers.  And that lock stays held unless it
54 * needs to be dropped to allow reentering this driver ... like upcalls to
55 * the gadget driver, or adjusting endpoint halt status.
56 */
57
58static char *decode_ep0stage(u8 stage)
59{
60	switch (stage) {
61	case MUSB_EP0_STAGE_SETUP:	return "idle";
62	case MUSB_EP0_STAGE_TX:		return "in";
63	case MUSB_EP0_STAGE_RX:		return "out";
64	case MUSB_EP0_STAGE_ACKWAIT:	return "wait";
65	case MUSB_EP0_STAGE_STATUSIN:	return "in/status";
66	case MUSB_EP0_STAGE_STATUSOUT:	return "out/status";
67	default:			return "?";
68	}
69}
70
71/* handle a standard GET_STATUS request
72 * Context:  caller holds controller lock
73 */
74static int service_tx_status_request(
75	struct musb *musb,
76	const struct usb_ctrlrequest *ctrlrequest)
77{
78	void __iomem	*mbase = musb->mregs;
79	int handled = 1;
80	u8 result[2], epnum = 0;
81	const u8 recip = ctrlrequest->bRequestType & USB_RECIP_MASK;
82
83	result[1] = 0;
84
85	switch (recip) {
86	case USB_RECIP_DEVICE:
87		result[0] = musb->is_self_powered << USB_DEVICE_SELF_POWERED;
88		result[0] |= musb->may_wakeup << USB_DEVICE_REMOTE_WAKEUP;
89#ifdef CONFIG_USB_MUSB_OTG
90		if (musb->g.is_otg) {
91			result[0] |= musb->g.b_hnp_enable
92				<< USB_DEVICE_B_HNP_ENABLE;
93			result[0] |= musb->g.a_alt_hnp_support
94				<< USB_DEVICE_A_ALT_HNP_SUPPORT;
95			result[0] |= musb->g.a_hnp_support
96				<< USB_DEVICE_A_HNP_SUPPORT;
97		}
98#endif
99		break;
100
101	case USB_RECIP_INTERFACE:
102		result[0] = 0;
103		break;
104
105	case USB_RECIP_ENDPOINT: {
106		int		is_in;
107		struct musb_ep	*ep;
108		u16		tmp;
109		void __iomem	*regs;
110
111		epnum = (u8) ctrlrequest->wIndex;
112		if (!epnum) {
113			result[0] = 0;
114			break;
115		}
116
117		is_in = epnum & USB_DIR_IN;
118		if (is_in) {
119			epnum &= 0x0f;
120			ep = &musb->endpoints[epnum].ep_in;
121		} else {
122			ep = &musb->endpoints[epnum].ep_out;
123		}
124		regs = musb->endpoints[epnum].regs;
125
126		if (epnum >= MUSB_C_NUM_EPS || !ep->desc) {
127			handled = -EINVAL;
128			break;
129		}
130
131		musb_ep_select(mbase, epnum);
132		if (is_in)
133			tmp = musb_readw(regs, MUSB_TXCSR)
134						& MUSB_TXCSR_P_SENDSTALL;
135		else
136			tmp = musb_readw(regs, MUSB_RXCSR)
137						& MUSB_RXCSR_P_SENDSTALL;
138		musb_ep_select(mbase, 0);
139
140		result[0] = tmp ? 1 : 0;
141		} break;
142
143	default:
144		/* class, vendor, etc ... delegate */
145		handled = 0;
146		break;
147	}
148
149	/* fill up the fifo; caller updates csr0 */
150	if (handled > 0) {
151		u16	len = le16_to_cpu(ctrlrequest->wLength);
152
153		if (len > 2)
154			len = 2;
155		musb_write_fifo(&musb->endpoints[0], len, result);
156	}
157
158	return handled;
159}
160
161/*
162 * handle a control-IN request, the end0 buffer contains the current request
163 * that is supposed to be a standard control request. Assumes the fifo to
164 * be at least 2 bytes long.
165 *
166 * @return 0 if the request was NOT HANDLED,
167 * < 0 when error
168 * > 0 when the request is processed
169 *
170 * Context:  caller holds controller lock
171 */
172static int
173service_in_request(struct musb *musb, const struct usb_ctrlrequest *ctrlrequest)
174{
175	int handled = 0;	/* not handled */
176
177	if ((ctrlrequest->bRequestType & USB_TYPE_MASK)
178			== USB_TYPE_STANDARD) {
179		switch (ctrlrequest->bRequest) {
180		case USB_REQ_GET_STATUS:
181			handled = service_tx_status_request(musb,
182					ctrlrequest);
183			break;
184
185		/* case USB_REQ_SYNC_FRAME: */
186
187		default:
188			break;
189		}
190	}
191	return handled;
192}
193
194/*
195 * Context:  caller holds controller lock
196 */
197static void musb_g_ep0_giveback(struct musb *musb, struct usb_request *req)
198{
199	musb_g_giveback(&musb->endpoints[0].ep_in, req, 0);
200	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
201}
202
203/*
204 * Tries to start B-device HNP negotiation if enabled via sysfs
205 */
206static inline void musb_try_b_hnp_enable(struct musb *musb)
207{
208	void __iomem	*mbase = musb->mregs;
209	u8		devctl;
210
211	DBG(1, "HNP: Setting HR\n");
212	devctl = musb_readb(mbase, MUSB_DEVCTL);
213	musb_writeb(mbase, MUSB_DEVCTL, devctl | MUSB_DEVCTL_HR);
214}
215
216/*
217 * Handle all control requests with no DATA stage, including standard
218 * requests such as:
219 * USB_REQ_SET_CONFIGURATION, USB_REQ_SET_INTERFACE, unrecognized
220 *	always delegated to the gadget driver
221 * USB_REQ_SET_ADDRESS, USB_REQ_CLEAR_FEATURE, USB_REQ_SET_FEATURE
222 *	always handled here, except for class/vendor/... features
223 *
224 * Context:  caller holds controller lock
225 */
226static int
227service_zero_data_request(struct musb *musb,
228		struct usb_ctrlrequest *ctrlrequest)
229__releases(musb->lock)
230__acquires(musb->lock)
231{
232	int handled = -EINVAL;
233	void __iomem *mbase = musb->mregs;
234	const u8 recip = ctrlrequest->bRequestType & USB_RECIP_MASK;
235
236	/* the gadget driver handles everything except what we MUST handle */
237	if ((ctrlrequest->bRequestType & USB_TYPE_MASK)
238			== USB_TYPE_STANDARD) {
239		switch (ctrlrequest->bRequest) {
240		case USB_REQ_SET_ADDRESS:
241			/* change it after the status stage */
242			musb->set_address = true;
243			musb->address = (u8) (ctrlrequest->wValue & 0x7f);
244			handled = 1;
245			break;
246
247		case USB_REQ_CLEAR_FEATURE:
248			switch (recip) {
249			case USB_RECIP_DEVICE:
250				if (ctrlrequest->wValue
251						!= USB_DEVICE_REMOTE_WAKEUP)
252					break;
253				musb->may_wakeup = 0;
254				handled = 1;
255				break;
256			case USB_RECIP_INTERFACE:
257				break;
258			case USB_RECIP_ENDPOINT:{
259				const u8 num = ctrlrequest->wIndex & 0x0f;
260				struct musb_ep *musb_ep;
261
262				if (num == 0
263						|| num >= MUSB_C_NUM_EPS
264						|| ctrlrequest->wValue
265							!= USB_ENDPOINT_HALT)
266					break;
267
268				if (ctrlrequest->wIndex & USB_DIR_IN)
269					musb_ep = &musb->endpoints[num].ep_in;
270				else
271					musb_ep = &musb->endpoints[num].ep_out;
272				if (!musb_ep->desc)
273					break;
274
275				/* REVISIT do it directly, no locking games */
276				spin_unlock(&musb->lock);
277				musb_gadget_set_halt(&musb_ep->end_point, 0);
278				spin_lock(&musb->lock);
279
280				/* select ep0 again */
281				musb_ep_select(mbase, 0);
282				handled = 1;
283				} break;
284			default:
285				/* class, vendor, etc ... delegate */
286				handled = 0;
287				break;
288			}
289			break;
290
291		case USB_REQ_SET_FEATURE:
292			switch (recip) {
293			case USB_RECIP_DEVICE:
294				handled = 1;
295				switch (ctrlrequest->wValue) {
296				case USB_DEVICE_REMOTE_WAKEUP:
297					musb->may_wakeup = 1;
298					break;
299				case USB_DEVICE_TEST_MODE:
300					if (musb->g.speed != USB_SPEED_HIGH)
301						goto stall;
302					if (ctrlrequest->wIndex & 0xff)
303						goto stall;
304
305					switch (ctrlrequest->wIndex >> 8) {
306					case 1:
307						pr_debug("TEST_J\n");
308						/* TEST_J */
309						musb->test_mode_nr =
310							MUSB_TEST_J;
311						break;
312					case 2:
313						/* TEST_K */
314						pr_debug("TEST_K\n");
315						musb->test_mode_nr =
316							MUSB_TEST_K;
317						break;
318					case 3:
319						/* TEST_SE0_NAK */
320						pr_debug("TEST_SE0_NAK\n");
321						musb->test_mode_nr =
322							MUSB_TEST_SE0_NAK;
323						break;
324					case 4:
325						/* TEST_PACKET */
326						pr_debug("TEST_PACKET\n");
327						musb->test_mode_nr =
328							MUSB_TEST_PACKET;
329						break;
330					default:
331						goto stall;
332					}
333
334					/* enter test mode after irq */
335					if (handled > 0)
336						musb->test_mode = true;
337					break;
338#ifdef CONFIG_USB_MUSB_OTG
339				case USB_DEVICE_B_HNP_ENABLE:
340					if (!musb->g.is_otg)
341						goto stall;
342					musb->g.b_hnp_enable = 1;
343					musb_try_b_hnp_enable(musb);
344					break;
345				case USB_DEVICE_A_HNP_SUPPORT:
346					if (!musb->g.is_otg)
347						goto stall;
348					musb->g.a_hnp_support = 1;
349					break;
350				case USB_DEVICE_A_ALT_HNP_SUPPORT:
351					if (!musb->g.is_otg)
352						goto stall;
353					musb->g.a_alt_hnp_support = 1;
354					break;
355#endif
356stall:
357				default:
358					handled = -EINVAL;
359					break;
360				}
361				break;
362
363			case USB_RECIP_INTERFACE:
364				break;
365
366			case USB_RECIP_ENDPOINT:{
367				const u8		epnum =
368					ctrlrequest->wIndex & 0x0f;
369				struct musb_ep		*musb_ep;
370				struct musb_hw_ep	*ep;
371				void __iomem		*regs;
372				int			is_in;
373				u16			csr;
374
375				if (epnum == 0
376						|| epnum >= MUSB_C_NUM_EPS
377						|| ctrlrequest->wValue
378							!= USB_ENDPOINT_HALT)
379					break;
380
381				ep = musb->endpoints + epnum;
382				regs = ep->regs;
383				is_in = ctrlrequest->wIndex & USB_DIR_IN;
384				if (is_in)
385					musb_ep = &ep->ep_in;
386				else
387					musb_ep = &ep->ep_out;
388				if (!musb_ep->desc)
389					break;
390
391				musb_ep_select(mbase, epnum);
392				if (is_in) {
393					csr = musb_readw(regs,
394							MUSB_TXCSR);
395					if (csr & MUSB_TXCSR_FIFONOTEMPTY)
396						csr |= MUSB_TXCSR_FLUSHFIFO;
397					csr |= MUSB_TXCSR_P_SENDSTALL
398						| MUSB_TXCSR_CLRDATATOG
399						| MUSB_TXCSR_P_WZC_BITS;
400					musb_writew(regs, MUSB_TXCSR,
401							csr);
402				} else {
403					csr = musb_readw(regs,
404							MUSB_RXCSR);
405					csr |= MUSB_RXCSR_P_SENDSTALL
406						| MUSB_RXCSR_FLUSHFIFO
407						| MUSB_RXCSR_CLRDATATOG
408						| MUSB_TXCSR_P_WZC_BITS;
409					musb_writew(regs, MUSB_RXCSR,
410							csr);
411				}
412
413				/* select ep0 again */
414				musb_ep_select(mbase, 0);
415				handled = 1;
416				} break;
417
418			default:
419				/* class, vendor, etc ... delegate */
420				handled = 0;
421				break;
422			}
423			break;
424		default:
425			/* delegate SET_CONFIGURATION, etc */
426			handled = 0;
427		}
428	} else
429		handled = 0;
430	return handled;
431}
432
433/* we have an ep0out data packet
434 * Context:  caller holds controller lock
435 */
436static void ep0_rxstate(struct musb *musb)
437{
438	void __iomem		*regs = musb->control_ep->regs;
439	struct usb_request	*req;
440	u16			tmp;
441
442	req = next_ep0_request(musb);
443
444	/* read packet and ack; or stall because of gadget driver bug:
445	 * should have provided the rx buffer before setup() returned.
446	 */
447	if (req) {
448		void		*buf = req->buf + req->actual;
449		unsigned	len = req->length - req->actual;
450
451		/* read the buffer */
452		tmp = musb_readb(regs, MUSB_COUNT0);
453		if (tmp > len) {
454			req->status = -EOVERFLOW;
455			tmp = len;
456		}
457		musb_read_fifo(&musb->endpoints[0], tmp, buf);
458		req->actual += tmp;
459		tmp = MUSB_CSR0_P_SVDRXPKTRDY;
460		if (tmp < 64 || req->actual == req->length) {
461			musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
462			tmp |= MUSB_CSR0_P_DATAEND;
463		} else
464			req = NULL;
465	} else
466		tmp = MUSB_CSR0_P_SVDRXPKTRDY | MUSB_CSR0_P_SENDSTALL;
467
468
469	/* Completion handler may choose to stall, e.g. because the
470	 * message just received holds invalid data.
471	 */
472	if (req) {
473		musb->ackpend = tmp;
474		musb_g_ep0_giveback(musb, req);
475		if (!musb->ackpend)
476			return;
477		musb->ackpend = 0;
478	}
479	musb_writew(regs, MUSB_CSR0, tmp);
480}
481
482/*
483 * transmitting to the host (IN), this code might be called from IRQ
484 * and from kernel thread.
485 *
486 * Context:  caller holds controller lock
487 */
488static void ep0_txstate(struct musb *musb)
489{
490	void __iomem		*regs = musb->control_ep->regs;
491	struct usb_request	*request = next_ep0_request(musb);
492	u16			csr = MUSB_CSR0_TXPKTRDY;
493	u8			*fifo_src;
494	u8			fifo_count;
495
496	if (!request) {
497		/* WARN_ON(1); */
498		DBG(2, "odd; csr0 %04x\n", musb_readw(regs, MUSB_CSR0));
499		return;
500	}
501
502	/* load the data */
503	fifo_src = (u8 *) request->buf + request->actual;
504	fifo_count = min((unsigned) MUSB_EP0_FIFOSIZE,
505		request->length - request->actual);
506	musb_write_fifo(&musb->endpoints[0], fifo_count, fifo_src);
507	request->actual += fifo_count;
508
509	/* update the flags */
510	if (fifo_count < MUSB_MAX_END0_PACKET
511			|| request->actual == request->length) {
512		musb->ep0_state = MUSB_EP0_STAGE_STATUSOUT;
513		csr |= MUSB_CSR0_P_DATAEND;
514	} else
515		request = NULL;
516
517	/* report completions as soon as the fifo's loaded; there's no
518	 * win in waiting till this last packet gets acked.  (other than
519	 * very precise fault reporting, needed by USB TMC; possible with
520	 * this hardware, but not usable from portable gadget drivers.)
521	 */
522	if (request) {
523		musb->ackpend = csr;
524		musb_g_ep0_giveback(musb, request);
525		if (!musb->ackpend)
526			return;
527		musb->ackpend = 0;
528	}
529
530	/* send it out, triggering a "txpktrdy cleared" irq */
531	musb_writew(regs, MUSB_CSR0, csr);
532}
533
534/*
535 * Read a SETUP packet (struct usb_ctrlrequest) from the hardware.
536 * Fields are left in USB byte-order.
537 *
538 * Context:  caller holds controller lock.
539 */
540static void
541musb_read_setup(struct musb *musb, struct usb_ctrlrequest *req)
542{
543	struct usb_request	*r;
544	void __iomem		*regs = musb->control_ep->regs;
545
546	musb_read_fifo(&musb->endpoints[0], sizeof *req, (u8 *)req);
547
548	/* NOTE:  earlier 2.6 versions changed setup packets to host
549	 * order, but now USB packets always stay in USB byte order.
550	 */
551	DBG(3, "SETUP req%02x.%02x v%04x i%04x l%d\n",
552		req->bRequestType,
553		req->bRequest,
554		le16_to_cpu(req->wValue),
555		le16_to_cpu(req->wIndex),
556		le16_to_cpu(req->wLength));
557
558	/* clean up any leftover transfers */
559	r = next_ep0_request(musb);
560	if (r)
561		musb_g_ep0_giveback(musb, r);
562
563	/* For zero-data requests we want to delay the STATUS stage to
564	 * avoid SETUPEND errors.  If we read data (OUT), delay accepting
565	 * packets until there's a buffer to store them in.
566	 *
567	 * If we write data, the controller acts happier if we enable
568	 * the TX FIFO right away, and give the controller a moment
569	 * to switch modes...
570	 */
571	musb->set_address = false;
572	musb->ackpend = MUSB_CSR0_P_SVDRXPKTRDY;
573	if (req->wLength == 0) {
574		if (req->bRequestType & USB_DIR_IN)
575			musb->ackpend |= MUSB_CSR0_TXPKTRDY;
576		musb->ep0_state = MUSB_EP0_STAGE_ACKWAIT;
577	} else if (req->bRequestType & USB_DIR_IN) {
578		musb->ep0_state = MUSB_EP0_STAGE_TX;
579		musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SVDRXPKTRDY);
580		while ((musb_readw(regs, MUSB_CSR0)
581				& MUSB_CSR0_RXPKTRDY) != 0)
582			cpu_relax();
583		musb->ackpend = 0;
584	} else
585		musb->ep0_state = MUSB_EP0_STAGE_RX;
586}
587
588static int
589forward_to_driver(struct musb *musb, const struct usb_ctrlrequest *ctrlrequest)
590__releases(musb->lock)
591__acquires(musb->lock)
592{
593	int retval;
594	if (!musb->gadget_driver)
595		return -EOPNOTSUPP;
596	spin_unlock(&musb->lock);
597	retval = musb->gadget_driver->setup(&musb->g, ctrlrequest);
598	spin_lock(&musb->lock);
599	return retval;
600}
601
602/*
603 * Handle peripheral ep0 interrupt
604 *
605 * Context: irq handler; we won't re-enter the driver that way.
606 */
607irqreturn_t musb_g_ep0_irq(struct musb *musb)
608{
609	u16		csr;
610	u16		len;
611	void __iomem	*mbase = musb->mregs;
612	void __iomem	*regs = musb->endpoints[0].regs;
613	irqreturn_t	retval = IRQ_NONE;
614
615	musb_ep_select(mbase, 0);	/* select ep0 */
616	csr = musb_readw(regs, MUSB_CSR0);
617	len = musb_readb(regs, MUSB_COUNT0);
618
619	DBG(4, "csr %04x, count %d, myaddr %d, ep0stage %s\n",
620			csr, len,
621			musb_readb(mbase, MUSB_FADDR),
622			decode_ep0stage(musb->ep0_state));
623
624	/* I sent a stall.. need to acknowledge it now.. */
625	if (csr & MUSB_CSR0_P_SENTSTALL) {
626		musb_writew(regs, MUSB_CSR0,
627				csr & ~MUSB_CSR0_P_SENTSTALL);
628		retval = IRQ_HANDLED;
629		musb->ep0_state = MUSB_EP0_STAGE_SETUP;
630		csr = musb_readw(regs, MUSB_CSR0);
631	}
632
633	/* request ended "early" */
634	if (csr & MUSB_CSR0_P_SETUPEND) {
635		musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SVDSETUPEND);
636		retval = IRQ_HANDLED;
637		musb->ep0_state = MUSB_EP0_STAGE_SETUP;
638		csr = musb_readw(regs, MUSB_CSR0);
639		/* NOTE:  request may need completion */
640	}
641
642	/* docs from Mentor only describe tx, rx, and idle/setup states.
643	 * we need to handle nuances around status stages, and also the
644	 * case where status and setup stages come back-to-back ...
645	 */
646	switch (musb->ep0_state) {
647
648	case MUSB_EP0_STAGE_TX:
649		/* irq on clearing txpktrdy */
650		if ((csr & MUSB_CSR0_TXPKTRDY) == 0) {
651			ep0_txstate(musb);
652			retval = IRQ_HANDLED;
653		}
654		break;
655
656	case MUSB_EP0_STAGE_RX:
657		/* irq on set rxpktrdy */
658		if (csr & MUSB_CSR0_RXPKTRDY) {
659			ep0_rxstate(musb);
660			retval = IRQ_HANDLED;
661		}
662		break;
663
664	case MUSB_EP0_STAGE_STATUSIN:
665		/* end of sequence #2 (OUT/RX state) or #3 (no data) */
666
667		/* update address (if needed) only @ the end of the
668		 * status phase per usb spec, which also guarantees
669		 * we get 10 msec to receive this irq... until this
670		 * is done we won't see the next packet.
671		 */
672		if (musb->set_address) {
673			musb->set_address = false;
674			musb_writeb(mbase, MUSB_FADDR, musb->address);
675		}
676
677		/* enter test mode if needed (exit by reset) */
678		else if (musb->test_mode) {
679			DBG(1, "entering TESTMODE\n");
680
681			if (MUSB_TEST_PACKET == musb->test_mode_nr)
682				musb_load_testpacket(musb);
683
684			musb_writeb(mbase, MUSB_TESTMODE,
685					musb->test_mode_nr);
686		}
687		/* FALLTHROUGH */
688
689	case MUSB_EP0_STAGE_STATUSOUT:
690		/* end of sequence #1: write to host (TX state) */
691		{
692			struct usb_request	*req;
693
694			req = next_ep0_request(musb);
695			if (req)
696				musb_g_ep0_giveback(musb, req);
697		}
698		retval = IRQ_HANDLED;
699		musb->ep0_state = MUSB_EP0_STAGE_SETUP;
700		/* FALLTHROUGH */
701
702	case MUSB_EP0_STAGE_SETUP:
703		if (csr & MUSB_CSR0_RXPKTRDY) {
704			struct usb_ctrlrequest	setup;
705			int			handled = 0;
706
707			if (len != 8) {
708				ERR("SETUP packet len %d != 8 ?\n", len);
709				break;
710			}
711			musb_read_setup(musb, &setup);
712			retval = IRQ_HANDLED;
713
714			/* sometimes the RESET won't be reported */
715			if (unlikely(musb->g.speed == USB_SPEED_UNKNOWN)) {
716				u8	power;
717
718				printk(KERN_NOTICE "%s: peripheral reset "
719						"irq lost!\n",
720						musb_driver_name);
721				power = musb_readb(mbase, MUSB_POWER);
722				musb->g.speed = (power & MUSB_POWER_HSMODE)
723					? USB_SPEED_HIGH : USB_SPEED_FULL;
724
725			}
726
727			switch (musb->ep0_state) {
728
729			/* sequence #3 (no data stage), includes requests
730			 * we can't forward (notably SET_ADDRESS and the
731			 * device/endpoint feature set/clear operations)
732			 * plus SET_CONFIGURATION and others we must
733			 */
734			case MUSB_EP0_STAGE_ACKWAIT:
735				handled = service_zero_data_request(
736						musb, &setup);
737
738				/* status stage might be immediate */
739				if (handled > 0) {
740					musb->ackpend |= MUSB_CSR0_P_DATAEND;
741					musb->ep0_state =
742						MUSB_EP0_STAGE_STATUSIN;
743				}
744				break;
745
746			/* sequence #1 (IN to host), includes GET_STATUS
747			 * requests that we can't forward, GET_DESCRIPTOR
748			 * and others that we must
749			 */
750			case MUSB_EP0_STAGE_TX:
751				handled = service_in_request(musb, &setup);
752				if (handled > 0) {
753					musb->ackpend = MUSB_CSR0_TXPKTRDY
754						| MUSB_CSR0_P_DATAEND;
755					musb->ep0_state =
756						MUSB_EP0_STAGE_STATUSOUT;
757				}
758				break;
759
760			/* sequence #2 (OUT from host), always forward */
761			default:		/* MUSB_EP0_STAGE_RX */
762				break;
763			}
764
765			DBG(3, "handled %d, csr %04x, ep0stage %s\n",
766				handled, csr,
767				decode_ep0stage(musb->ep0_state));
768
769			/* unless we need to delegate this to the gadget
770			 * driver, we know how to wrap this up:  csr0 has
771			 * not yet been written.
772			 */
773			if (handled < 0)
774				goto stall;
775			else if (handled > 0)
776				goto finish;
777
778			handled = forward_to_driver(musb, &setup);
779			if (handled < 0) {
780				musb_ep_select(mbase, 0);
781stall:
782				DBG(3, "stall (%d)\n", handled);
783				musb->ackpend |= MUSB_CSR0_P_SENDSTALL;
784				musb->ep0_state = MUSB_EP0_STAGE_SETUP;
785finish:
786				musb_writew(regs, MUSB_CSR0,
787						musb->ackpend);
788				musb->ackpend = 0;
789			}
790		}
791		break;
792
793	case MUSB_EP0_STAGE_ACKWAIT:
794		/* This should not happen. But happens with tusb6010 with
795		 * g_file_storage and high speed. Do nothing.
796		 */
797		retval = IRQ_HANDLED;
798		break;
799
800	default:
801		/* "can't happen" */
802		WARN_ON(1);
803		musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SENDSTALL);
804		musb->ep0_state = MUSB_EP0_STAGE_SETUP;
805		break;
806	}
807
808	return retval;
809}
810
811
812static int
813musb_g_ep0_enable(struct usb_ep *ep, const struct usb_endpoint_descriptor *desc)
814{
815	/* always enabled */
816	return -EINVAL;
817}
818
819static int musb_g_ep0_disable(struct usb_ep *e)
820{
821	/* always enabled */
822	return -EINVAL;
823}
824
825static int
826musb_g_ep0_queue(struct usb_ep *e, struct usb_request *r, gfp_t gfp_flags)
827{
828	struct musb_ep		*ep;
829	struct musb_request	*req;
830	struct musb		*musb;
831	int			status;
832	unsigned long		lockflags;
833	void __iomem		*regs;
834
835	if (!e || !r)
836		return -EINVAL;
837
838	ep = to_musb_ep(e);
839	musb = ep->musb;
840	regs = musb->control_ep->regs;
841
842	req = to_musb_request(r);
843	req->musb = musb;
844	req->request.actual = 0;
845	req->request.status = -EINPROGRESS;
846	req->tx = ep->is_in;
847
848	spin_lock_irqsave(&musb->lock, lockflags);
849
850	if (!list_empty(&ep->req_list)) {
851		status = -EBUSY;
852		goto cleanup;
853	}
854
855	switch (musb->ep0_state) {
856	case MUSB_EP0_STAGE_RX:		/* control-OUT data */
857	case MUSB_EP0_STAGE_TX:		/* control-IN data */
858	case MUSB_EP0_STAGE_ACKWAIT:	/* zero-length data */
859		status = 0;
860		break;
861	default:
862		DBG(1, "ep0 request queued in state %d\n",
863				musb->ep0_state);
864		status = -EINVAL;
865		goto cleanup;
866	}
867
868	/* add request to the list */
869	list_add_tail(&(req->request.list), &(ep->req_list));
870
871	DBG(3, "queue to %s (%s), length=%d\n",
872			ep->name, ep->is_in ? "IN/TX" : "OUT/RX",
873			req->request.length);
874
875	musb_ep_select(musb->mregs, 0);
876
877	/* sequence #1, IN ... start writing the data */
878	if (musb->ep0_state == MUSB_EP0_STAGE_TX)
879		ep0_txstate(musb);
880
881	/* sequence #3, no-data ... issue IN status */
882	else if (musb->ep0_state == MUSB_EP0_STAGE_ACKWAIT) {
883		if (req->request.length)
884			status = -EINVAL;
885		else {
886			musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
887			musb_writew(regs, MUSB_CSR0,
888					musb->ackpend | MUSB_CSR0_P_DATAEND);
889			musb->ackpend = 0;
890			musb_g_ep0_giveback(ep->musb, r);
891		}
892
893	/* else for sequence #2 (OUT), caller provides a buffer
894	 * before the next packet arrives.  deferred responses
895	 * (after SETUP is acked) are racey.
896	 */
897	} else if (musb->ackpend) {
898		musb_writew(regs, MUSB_CSR0, musb->ackpend);
899		musb->ackpend = 0;
900	}
901
902cleanup:
903	spin_unlock_irqrestore(&musb->lock, lockflags);
904	return status;
905}
906
907static int musb_g_ep0_dequeue(struct usb_ep *ep, struct usb_request *req)
908{
909	/* we just won't support this */
910	return -EINVAL;
911}
912
913static int musb_g_ep0_halt(struct usb_ep *e, int value)
914{
915	struct musb_ep		*ep;
916	struct musb		*musb;
917	void __iomem		*base, *regs;
918	unsigned long		flags;
919	int			status;
920	u16			csr;
921
922	if (!e || !value)
923		return -EINVAL;
924
925	ep = to_musb_ep(e);
926	musb = ep->musb;
927	base = musb->mregs;
928	regs = musb->control_ep->regs;
929	status = 0;
930
931	spin_lock_irqsave(&musb->lock, flags);
932
933	if (!list_empty(&ep->req_list)) {
934		status = -EBUSY;
935		goto cleanup;
936	}
937
938	musb_ep_select(base, 0);
939	csr = musb->ackpend;
940
941	switch (musb->ep0_state) {
942
943	/* Stalls are usually issued after parsing SETUP packet, either
944	 * directly in irq context from setup() or else later.
945	 */
946	case MUSB_EP0_STAGE_TX:		/* control-IN data */
947	case MUSB_EP0_STAGE_ACKWAIT:	/* STALL for zero-length data */
948	case MUSB_EP0_STAGE_RX:		/* control-OUT data */
949		csr = musb_readw(regs, MUSB_CSR0);
950		/* FALLTHROUGH */
951
952	/* It's also OK to issue stalls during callbacks when a non-empty
953	 * DATA stage buffer has been read (or even written).
954	 */
955	case MUSB_EP0_STAGE_STATUSIN:	/* control-OUT status */
956	case MUSB_EP0_STAGE_STATUSOUT:	/* control-IN status */
957
958		csr |= MUSB_CSR0_P_SENDSTALL;
959		musb_writew(regs, MUSB_CSR0, csr);
960		musb->ep0_state = MUSB_EP0_STAGE_SETUP;
961		musb->ackpend = 0;
962		break;
963	default:
964		DBG(1, "ep0 can't halt in state %d\n", musb->ep0_state);
965		status = -EINVAL;
966	}
967
968cleanup:
969	spin_unlock_irqrestore(&musb->lock, flags);
970	return status;
971}
972
973const struct usb_ep_ops musb_g_ep0_ops = {
974	.enable		= musb_g_ep0_enable,
975	.disable	= musb_g_ep0_disable,
976	.alloc_request	= musb_alloc_request,
977	.free_request	= musb_free_request,
978	.queue		= musb_g_ep0_queue,
979	.dequeue	= musb_g_ep0_dequeue,
980	.set_halt	= musb_g_ep0_halt,
981};
982