musb_gadget_ep0.c revision d0390d92bf548a903a48e1a2b3a12eff8a9d838b
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 * Copyright (C) 2008-2009 MontaVista Software, Inc. <source@mvista.com>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * version 2 as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
21 * 02110-1301 USA
22 *
23 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
24 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
26 * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
29 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
30 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 *
34 */
35
36#include <linux/kernel.h>
37#include <linux/list.h>
38#include <linux/timer.h>
39#include <linux/spinlock.h>
40#include <linux/init.h>
41#include <linux/device.h>
42#include <linux/interrupt.h>
43
44#include "musb_core.h"
45
46/* ep0 is always musb->endpoints[0].ep_in */
47#define	next_ep0_request(musb)	next_in_request(&(musb)->endpoints[0])
48
49/*
50 * locking note:  we use only the controller lock, for simpler correctness.
51 * It's always held with IRQs blocked.
52 *
53 * It protects the ep0 request queue as well as ep0_state, not just the
54 * controller and indexed registers.  And that lock stays held unless it
55 * needs to be dropped to allow reentering this driver ... like upcalls to
56 * the gadget driver, or adjusting endpoint halt status.
57 */
58
59static char *decode_ep0stage(u8 stage)
60{
61	switch (stage) {
62	case MUSB_EP0_STAGE_IDLE:	return "idle";
63	case MUSB_EP0_STAGE_SETUP:	return "setup";
64	case MUSB_EP0_STAGE_TX:		return "in";
65	case MUSB_EP0_STAGE_RX:		return "out";
66	case MUSB_EP0_STAGE_ACKWAIT:	return "wait";
67	case MUSB_EP0_STAGE_STATUSIN:	return "in/status";
68	case MUSB_EP0_STAGE_STATUSOUT:	return "out/status";
69	default:			return "?";
70	}
71}
72
73/* handle a standard GET_STATUS request
74 * Context:  caller holds controller lock
75 */
76static int service_tx_status_request(
77	struct musb *musb,
78	const struct usb_ctrlrequest *ctrlrequest)
79{
80	void __iomem	*mbase = musb->mregs;
81	int handled = 1;
82	u8 result[2], epnum = 0;
83	const u8 recip = ctrlrequest->bRequestType & USB_RECIP_MASK;
84
85	result[1] = 0;
86
87	switch (recip) {
88	case USB_RECIP_DEVICE:
89		result[0] = musb->is_self_powered << USB_DEVICE_SELF_POWERED;
90		result[0] |= musb->may_wakeup << USB_DEVICE_REMOTE_WAKEUP;
91#ifdef CONFIG_USB_MUSB_OTG
92		if (musb->g.is_otg) {
93			result[0] |= musb->g.b_hnp_enable
94				<< USB_DEVICE_B_HNP_ENABLE;
95			result[0] |= musb->g.a_alt_hnp_support
96				<< USB_DEVICE_A_ALT_HNP_SUPPORT;
97			result[0] |= musb->g.a_hnp_support
98				<< USB_DEVICE_A_HNP_SUPPORT;
99		}
100#endif
101		break;
102
103	case USB_RECIP_INTERFACE:
104		result[0] = 0;
105		break;
106
107	case USB_RECIP_ENDPOINT: {
108		int		is_in;
109		struct musb_ep	*ep;
110		u16		tmp;
111		void __iomem	*regs;
112
113		epnum = (u8) ctrlrequest->wIndex;
114		if (!epnum) {
115			result[0] = 0;
116			break;
117		}
118
119		is_in = epnum & USB_DIR_IN;
120		if (is_in) {
121			epnum &= 0x0f;
122			ep = &musb->endpoints[epnum].ep_in;
123		} else {
124			ep = &musb->endpoints[epnum].ep_out;
125		}
126		regs = musb->endpoints[epnum].regs;
127
128		if (epnum >= MUSB_C_NUM_EPS || !ep->desc) {
129			handled = -EINVAL;
130			break;
131		}
132
133		musb_ep_select(mbase, epnum);
134		if (is_in)
135			tmp = musb_readw(regs, MUSB_TXCSR)
136						& MUSB_TXCSR_P_SENDSTALL;
137		else
138			tmp = musb_readw(regs, MUSB_RXCSR)
139						& MUSB_RXCSR_P_SENDSTALL;
140		musb_ep_select(mbase, 0);
141
142		result[0] = tmp ? 1 : 0;
143		} break;
144
145	default:
146		/* class, vendor, etc ... delegate */
147		handled = 0;
148		break;
149	}
150
151	/* fill up the fifo; caller updates csr0 */
152	if (handled > 0) {
153		u16	len = le16_to_cpu(ctrlrequest->wLength);
154
155		if (len > 2)
156			len = 2;
157		musb_write_fifo(&musb->endpoints[0], len, result);
158	}
159
160	return handled;
161}
162
163/*
164 * handle a control-IN request, the end0 buffer contains the current request
165 * that is supposed to be a standard control request. Assumes the fifo to
166 * be at least 2 bytes long.
167 *
168 * @return 0 if the request was NOT HANDLED,
169 * < 0 when error
170 * > 0 when the request is processed
171 *
172 * Context:  caller holds controller lock
173 */
174static int
175service_in_request(struct musb *musb, const struct usb_ctrlrequest *ctrlrequest)
176{
177	int handled = 0;	/* not handled */
178
179	if ((ctrlrequest->bRequestType & USB_TYPE_MASK)
180			== USB_TYPE_STANDARD) {
181		switch (ctrlrequest->bRequest) {
182		case USB_REQ_GET_STATUS:
183			handled = service_tx_status_request(musb,
184					ctrlrequest);
185			break;
186
187		/* case USB_REQ_SYNC_FRAME: */
188
189		default:
190			break;
191		}
192	}
193	return handled;
194}
195
196/*
197 * Context:  caller holds controller lock
198 */
199static void musb_g_ep0_giveback(struct musb *musb, struct usb_request *req)
200{
201	musb_g_giveback(&musb->endpoints[0].ep_in, req, 0);
202}
203
204/*
205 * Tries to start B-device HNP negotiation if enabled via sysfs
206 */
207static inline void musb_try_b_hnp_enable(struct musb *musb)
208{
209	void __iomem	*mbase = musb->mregs;
210	u8		devctl;
211
212	DBG(1, "HNP: Setting HR\n");
213	devctl = musb_readb(mbase, MUSB_DEVCTL);
214	musb_writeb(mbase, MUSB_DEVCTL, devctl | MUSB_DEVCTL_HR);
215}
216
217/*
218 * Handle all control requests with no DATA stage, including standard
219 * requests such as:
220 * USB_REQ_SET_CONFIGURATION, USB_REQ_SET_INTERFACE, unrecognized
221 *	always delegated to the gadget driver
222 * USB_REQ_SET_ADDRESS, USB_REQ_CLEAR_FEATURE, USB_REQ_SET_FEATURE
223 *	always handled here, except for class/vendor/... features
224 *
225 * Context:  caller holds controller lock
226 */
227static int
228service_zero_data_request(struct musb *musb,
229		struct usb_ctrlrequest *ctrlrequest)
230__releases(musb->lock)
231__acquires(musb->lock)
232{
233	int handled = -EINVAL;
234	void __iomem *mbase = musb->mregs;
235	const u8 recip = ctrlrequest->bRequestType & USB_RECIP_MASK;
236
237	/* the gadget driver handles everything except what we MUST handle */
238	if ((ctrlrequest->bRequestType & USB_TYPE_MASK)
239			== USB_TYPE_STANDARD) {
240		switch (ctrlrequest->bRequest) {
241		case USB_REQ_SET_ADDRESS:
242			/* change it after the status stage */
243			musb->set_address = true;
244			musb->address = (u8) (ctrlrequest->wValue & 0x7f);
245			handled = 1;
246			break;
247
248		case USB_REQ_CLEAR_FEATURE:
249			switch (recip) {
250			case USB_RECIP_DEVICE:
251				if (ctrlrequest->wValue
252						!= USB_DEVICE_REMOTE_WAKEUP)
253					break;
254				musb->may_wakeup = 0;
255				handled = 1;
256				break;
257			case USB_RECIP_INTERFACE:
258				break;
259			case USB_RECIP_ENDPOINT:{
260				const u8		epnum =
261					ctrlrequest->wIndex & 0x0f;
262				struct musb_ep		*musb_ep;
263				struct musb_hw_ep	*ep;
264				void __iomem		*regs;
265				int			is_in;
266				u16			csr;
267
268				if (epnum == 0 || epnum >= MUSB_C_NUM_EPS ||
269				    ctrlrequest->wValue != USB_ENDPOINT_HALT)
270					break;
271
272				ep = musb->endpoints + epnum;
273				regs = ep->regs;
274				is_in = ctrlrequest->wIndex & USB_DIR_IN;
275				if (is_in)
276					musb_ep = &ep->ep_in;
277				else
278					musb_ep = &ep->ep_out;
279				if (!musb_ep->desc)
280					break;
281
282				handled = 1;
283				/* Ignore request if endpoint is wedged */
284				if (musb_ep->wedged)
285					break;
286
287				musb_ep_select(mbase, epnum);
288				if (is_in) {
289					csr  = musb_readw(regs, MUSB_TXCSR);
290					csr |= MUSB_TXCSR_CLRDATATOG |
291					       MUSB_TXCSR_P_WZC_BITS;
292					csr &= ~(MUSB_TXCSR_P_SENDSTALL |
293						 MUSB_TXCSR_P_SENTSTALL |
294						 MUSB_TXCSR_TXPKTRDY);
295					musb_writew(regs, MUSB_TXCSR, csr);
296				} else {
297					csr  = musb_readw(regs, MUSB_RXCSR);
298					csr |= MUSB_RXCSR_CLRDATATOG |
299					       MUSB_RXCSR_P_WZC_BITS;
300					csr &= ~(MUSB_RXCSR_P_SENDSTALL |
301						 MUSB_RXCSR_P_SENTSTALL);
302					musb_writew(regs, MUSB_RXCSR, csr);
303				}
304
305				/* select ep0 again */
306				musb_ep_select(mbase, 0);
307				} break;
308			default:
309				/* class, vendor, etc ... delegate */
310				handled = 0;
311				break;
312			}
313			break;
314
315		case USB_REQ_SET_FEATURE:
316			switch (recip) {
317			case USB_RECIP_DEVICE:
318				handled = 1;
319				switch (ctrlrequest->wValue) {
320				case USB_DEVICE_REMOTE_WAKEUP:
321					musb->may_wakeup = 1;
322					break;
323				case USB_DEVICE_TEST_MODE:
324					if (musb->g.speed != USB_SPEED_HIGH)
325						goto stall;
326					if (ctrlrequest->wIndex & 0xff)
327						goto stall;
328
329					switch (ctrlrequest->wIndex >> 8) {
330					case 1:
331						pr_debug("TEST_J\n");
332						/* TEST_J */
333						musb->test_mode_nr =
334							MUSB_TEST_J;
335						break;
336					case 2:
337						/* TEST_K */
338						pr_debug("TEST_K\n");
339						musb->test_mode_nr =
340							MUSB_TEST_K;
341						break;
342					case 3:
343						/* TEST_SE0_NAK */
344						pr_debug("TEST_SE0_NAK\n");
345						musb->test_mode_nr =
346							MUSB_TEST_SE0_NAK;
347						break;
348					case 4:
349						/* TEST_PACKET */
350						pr_debug("TEST_PACKET\n");
351						musb->test_mode_nr =
352							MUSB_TEST_PACKET;
353						break;
354
355					case 0xc0:
356						/* TEST_FORCE_HS */
357						pr_debug("TEST_FORCE_HS\n");
358						musb->test_mode_nr =
359							MUSB_TEST_FORCE_HS;
360						break;
361					case 0xc1:
362						/* TEST_FORCE_FS */
363						pr_debug("TEST_FORCE_FS\n");
364						musb->test_mode_nr =
365							MUSB_TEST_FORCE_FS;
366						break;
367					case 0xc2:
368						/* TEST_FIFO_ACCESS */
369						pr_debug("TEST_FIFO_ACCESS\n");
370						musb->test_mode_nr =
371							MUSB_TEST_FIFO_ACCESS;
372						break;
373					case 0xc3:
374						/* TEST_FORCE_HOST */
375						pr_debug("TEST_FORCE_HOST\n");
376						musb->test_mode_nr =
377							MUSB_TEST_FORCE_HOST;
378						break;
379					default:
380						goto stall;
381					}
382
383					/* enter test mode after irq */
384					if (handled > 0)
385						musb->test_mode = true;
386					break;
387#ifdef CONFIG_USB_MUSB_OTG
388				case USB_DEVICE_B_HNP_ENABLE:
389					if (!musb->g.is_otg)
390						goto stall;
391					musb->g.b_hnp_enable = 1;
392					musb_try_b_hnp_enable(musb);
393					break;
394				case USB_DEVICE_A_HNP_SUPPORT:
395					if (!musb->g.is_otg)
396						goto stall;
397					musb->g.a_hnp_support = 1;
398					break;
399				case USB_DEVICE_A_ALT_HNP_SUPPORT:
400					if (!musb->g.is_otg)
401						goto stall;
402					musb->g.a_alt_hnp_support = 1;
403					break;
404#endif
405				case USB_DEVICE_DEBUG_MODE:
406					handled = 0;
407					break;
408stall:
409				default:
410					handled = -EINVAL;
411					break;
412				}
413				break;
414
415			case USB_RECIP_INTERFACE:
416				break;
417
418			case USB_RECIP_ENDPOINT:{
419				const u8		epnum =
420					ctrlrequest->wIndex & 0x0f;
421				struct musb_ep		*musb_ep;
422				struct musb_hw_ep	*ep;
423				void __iomem		*regs;
424				int			is_in;
425				u16			csr;
426
427				if (epnum == 0 || epnum >= MUSB_C_NUM_EPS ||
428				    ctrlrequest->wValue	!= USB_ENDPOINT_HALT)
429					break;
430
431				ep = musb->endpoints + epnum;
432				regs = ep->regs;
433				is_in = ctrlrequest->wIndex & USB_DIR_IN;
434				if (is_in)
435					musb_ep = &ep->ep_in;
436				else
437					musb_ep = &ep->ep_out;
438				if (!musb_ep->desc)
439					break;
440
441				musb_ep_select(mbase, epnum);
442				if (is_in) {
443					csr = musb_readw(regs, MUSB_TXCSR);
444					if (csr & MUSB_TXCSR_FIFONOTEMPTY)
445						csr |= MUSB_TXCSR_FLUSHFIFO;
446					csr |= MUSB_TXCSR_P_SENDSTALL
447						| MUSB_TXCSR_CLRDATATOG
448						| MUSB_TXCSR_P_WZC_BITS;
449					musb_writew(regs, MUSB_TXCSR, csr);
450				} else {
451					csr = musb_readw(regs, MUSB_RXCSR);
452					csr |= MUSB_RXCSR_P_SENDSTALL
453						| MUSB_RXCSR_FLUSHFIFO
454						| MUSB_RXCSR_CLRDATATOG
455						| MUSB_RXCSR_P_WZC_BITS;
456					musb_writew(regs, MUSB_RXCSR, csr);
457				}
458
459				/* select ep0 again */
460				musb_ep_select(mbase, 0);
461				handled = 1;
462				} break;
463
464			default:
465				/* class, vendor, etc ... delegate */
466				handled = 0;
467				break;
468			}
469			break;
470		default:
471			/* delegate SET_CONFIGURATION, etc */
472			handled = 0;
473		}
474	} else
475		handled = 0;
476	return handled;
477}
478
479/* we have an ep0out data packet
480 * Context:  caller holds controller lock
481 */
482static void ep0_rxstate(struct musb *musb)
483{
484	void __iomem		*regs = musb->control_ep->regs;
485	struct usb_request	*req;
486	u16			count, csr;
487
488	req = next_ep0_request(musb);
489
490	/* read packet and ack; or stall because of gadget driver bug:
491	 * should have provided the rx buffer before setup() returned.
492	 */
493	if (req) {
494		void		*buf = req->buf + req->actual;
495		unsigned	len = req->length - req->actual;
496
497		/* read the buffer */
498		count = musb_readb(regs, MUSB_COUNT0);
499		if (count > len) {
500			req->status = -EOVERFLOW;
501			count = len;
502		}
503		musb_read_fifo(&musb->endpoints[0], count, buf);
504		req->actual += count;
505		csr = MUSB_CSR0_P_SVDRXPKTRDY;
506		if (count < 64 || req->actual == req->length) {
507			musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
508			csr |= MUSB_CSR0_P_DATAEND;
509		} else
510			req = NULL;
511	} else
512		csr = MUSB_CSR0_P_SVDRXPKTRDY | MUSB_CSR0_P_SENDSTALL;
513
514
515	/* Completion handler may choose to stall, e.g. because the
516	 * message just received holds invalid data.
517	 */
518	if (req) {
519		musb->ackpend = csr;
520		musb_g_ep0_giveback(musb, req);
521		if (!musb->ackpend)
522			return;
523		musb->ackpend = 0;
524	}
525	musb_ep_select(musb->mregs, 0);
526	musb_writew(regs, MUSB_CSR0, csr);
527}
528
529/*
530 * transmitting to the host (IN), this code might be called from IRQ
531 * and from kernel thread.
532 *
533 * Context:  caller holds controller lock
534 */
535static void ep0_txstate(struct musb *musb)
536{
537	void __iomem		*regs = musb->control_ep->regs;
538	struct usb_request	*request = next_ep0_request(musb);
539	u16			csr = MUSB_CSR0_TXPKTRDY;
540	u8			*fifo_src;
541	u8			fifo_count;
542
543	if (!request) {
544		/* WARN_ON(1); */
545		DBG(2, "odd; csr0 %04x\n", musb_readw(regs, MUSB_CSR0));
546		return;
547	}
548
549	/* load the data */
550	fifo_src = (u8 *) request->buf + request->actual;
551	fifo_count = min((unsigned) MUSB_EP0_FIFOSIZE,
552		request->length - request->actual);
553	musb_write_fifo(&musb->endpoints[0], fifo_count, fifo_src);
554	request->actual += fifo_count;
555
556	/* update the flags */
557	if (fifo_count < MUSB_MAX_END0_PACKET
558			|| (request->actual == request->length
559				&& !request->zero)) {
560		musb->ep0_state = MUSB_EP0_STAGE_STATUSOUT;
561		csr |= MUSB_CSR0_P_DATAEND;
562	} else
563		request = NULL;
564
565	/* report completions as soon as the fifo's loaded; there's no
566	 * win in waiting till this last packet gets acked.  (other than
567	 * very precise fault reporting, needed by USB TMC; possible with
568	 * this hardware, but not usable from portable gadget drivers.)
569	 */
570	if (request) {
571		musb->ackpend = csr;
572		musb_g_ep0_giveback(musb, request);
573		if (!musb->ackpend)
574			return;
575		musb->ackpend = 0;
576	}
577
578	/* send it out, triggering a "txpktrdy cleared" irq */
579	musb_ep_select(musb->mregs, 0);
580	musb_writew(regs, MUSB_CSR0, csr);
581}
582
583/*
584 * Read a SETUP packet (struct usb_ctrlrequest) from the hardware.
585 * Fields are left in USB byte-order.
586 *
587 * Context:  caller holds controller lock.
588 */
589static void
590musb_read_setup(struct musb *musb, struct usb_ctrlrequest *req)
591{
592	struct usb_request	*r;
593	void __iomem		*regs = musb->control_ep->regs;
594
595	musb_read_fifo(&musb->endpoints[0], sizeof *req, (u8 *)req);
596
597	/* NOTE:  earlier 2.6 versions changed setup packets to host
598	 * order, but now USB packets always stay in USB byte order.
599	 */
600	DBG(3, "SETUP req%02x.%02x v%04x i%04x l%d\n",
601		req->bRequestType,
602		req->bRequest,
603		le16_to_cpu(req->wValue),
604		le16_to_cpu(req->wIndex),
605		le16_to_cpu(req->wLength));
606
607	/* clean up any leftover transfers */
608	r = next_ep0_request(musb);
609	if (r)
610		musb_g_ep0_giveback(musb, r);
611
612	/* For zero-data requests we want to delay the STATUS stage to
613	 * avoid SETUPEND errors.  If we read data (OUT), delay accepting
614	 * packets until there's a buffer to store them in.
615	 *
616	 * If we write data, the controller acts happier if we enable
617	 * the TX FIFO right away, and give the controller a moment
618	 * to switch modes...
619	 */
620	musb->set_address = false;
621	musb->ackpend = MUSB_CSR0_P_SVDRXPKTRDY;
622	if (req->wLength == 0) {
623		if (req->bRequestType & USB_DIR_IN)
624			musb->ackpend |= MUSB_CSR0_TXPKTRDY;
625		musb->ep0_state = MUSB_EP0_STAGE_ACKWAIT;
626	} else if (req->bRequestType & USB_DIR_IN) {
627		musb->ep0_state = MUSB_EP0_STAGE_TX;
628		musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SVDRXPKTRDY);
629		while ((musb_readw(regs, MUSB_CSR0)
630				& MUSB_CSR0_RXPKTRDY) != 0)
631			cpu_relax();
632		musb->ackpend = 0;
633	} else
634		musb->ep0_state = MUSB_EP0_STAGE_RX;
635}
636
637static int
638forward_to_driver(struct musb *musb, const struct usb_ctrlrequest *ctrlrequest)
639__releases(musb->lock)
640__acquires(musb->lock)
641{
642	int retval;
643	if (!musb->gadget_driver)
644		return -EOPNOTSUPP;
645	spin_unlock(&musb->lock);
646	retval = musb->gadget_driver->setup(&musb->g, ctrlrequest);
647	spin_lock(&musb->lock);
648	return retval;
649}
650
651/*
652 * Handle peripheral ep0 interrupt
653 *
654 * Context: irq handler; we won't re-enter the driver that way.
655 */
656irqreturn_t musb_g_ep0_irq(struct musb *musb)
657{
658	u16		csr;
659	u16		len;
660	void __iomem	*mbase = musb->mregs;
661	void __iomem	*regs = musb->endpoints[0].regs;
662	irqreturn_t	retval = IRQ_NONE;
663
664	musb_ep_select(mbase, 0);	/* select ep0 */
665	csr = musb_readw(regs, MUSB_CSR0);
666	len = musb_readb(regs, MUSB_COUNT0);
667
668	DBG(4, "csr %04x, count %d, myaddr %d, ep0stage %s\n",
669			csr, len,
670			musb_readb(mbase, MUSB_FADDR),
671			decode_ep0stage(musb->ep0_state));
672
673	/* I sent a stall.. need to acknowledge it now.. */
674	if (csr & MUSB_CSR0_P_SENTSTALL) {
675		musb_writew(regs, MUSB_CSR0,
676				csr & ~MUSB_CSR0_P_SENTSTALL);
677		retval = IRQ_HANDLED;
678		musb->ep0_state = MUSB_EP0_STAGE_IDLE;
679		csr = musb_readw(regs, MUSB_CSR0);
680	}
681
682	/* request ended "early" */
683	if (csr & MUSB_CSR0_P_SETUPEND) {
684		musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SVDSETUPEND);
685		retval = IRQ_HANDLED;
686		/* Transition into the early status phase */
687		switch (musb->ep0_state) {
688		case MUSB_EP0_STAGE_TX:
689			musb->ep0_state = MUSB_EP0_STAGE_STATUSOUT;
690			break;
691		case MUSB_EP0_STAGE_RX:
692			musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
693			break;
694		default:
695			ERR("SetupEnd came in a wrong ep0stage %s\n",
696			    decode_ep0stage(musb->ep0_state));
697		}
698		csr = musb_readw(regs, MUSB_CSR0);
699		/* NOTE:  request may need completion */
700	}
701
702	/* docs from Mentor only describe tx, rx, and idle/setup states.
703	 * we need to handle nuances around status stages, and also the
704	 * case where status and setup stages come back-to-back ...
705	 */
706	switch (musb->ep0_state) {
707
708	case MUSB_EP0_STAGE_TX:
709		/* irq on clearing txpktrdy */
710		if ((csr & MUSB_CSR0_TXPKTRDY) == 0) {
711			ep0_txstate(musb);
712			retval = IRQ_HANDLED;
713		}
714		break;
715
716	case MUSB_EP0_STAGE_RX:
717		/* irq on set rxpktrdy */
718		if (csr & MUSB_CSR0_RXPKTRDY) {
719			ep0_rxstate(musb);
720			retval = IRQ_HANDLED;
721		}
722		break;
723
724	case MUSB_EP0_STAGE_STATUSIN:
725		/* end of sequence #2 (OUT/RX state) or #3 (no data) */
726
727		/* update address (if needed) only @ the end of the
728		 * status phase per usb spec, which also guarantees
729		 * we get 10 msec to receive this irq... until this
730		 * is done we won't see the next packet.
731		 */
732		if (musb->set_address) {
733			musb->set_address = false;
734			musb_writeb(mbase, MUSB_FADDR, musb->address);
735		}
736
737		/* enter test mode if needed (exit by reset) */
738		else if (musb->test_mode) {
739			DBG(1, "entering TESTMODE\n");
740
741			if (MUSB_TEST_PACKET == musb->test_mode_nr)
742				musb_load_testpacket(musb);
743
744			musb_writeb(mbase, MUSB_TESTMODE,
745					musb->test_mode_nr);
746		}
747		/* FALLTHROUGH */
748
749	case MUSB_EP0_STAGE_STATUSOUT:
750		/* end of sequence #1: write to host (TX state) */
751		{
752			struct usb_request	*req;
753
754			req = next_ep0_request(musb);
755			if (req)
756				musb_g_ep0_giveback(musb, req);
757		}
758
759		/*
760		 * In case when several interrupts can get coalesced,
761		 * check to see if we've already received a SETUP packet...
762		 */
763		if (csr & MUSB_CSR0_RXPKTRDY)
764			goto setup;
765
766		retval = IRQ_HANDLED;
767		musb->ep0_state = MUSB_EP0_STAGE_IDLE;
768		break;
769
770	case MUSB_EP0_STAGE_IDLE:
771		/*
772		 * This state is typically (but not always) indiscernible
773		 * from the status states since the corresponding interrupts
774		 * tend to happen within too little period of time (with only
775		 * a zero-length packet in between) and so get coalesced...
776		 */
777		retval = IRQ_HANDLED;
778		musb->ep0_state = MUSB_EP0_STAGE_SETUP;
779		/* FALLTHROUGH */
780
781	case MUSB_EP0_STAGE_SETUP:
782setup:
783		if (csr & MUSB_CSR0_RXPKTRDY) {
784			struct usb_ctrlrequest	setup;
785			int			handled = 0;
786
787			if (len != 8) {
788				ERR("SETUP packet len %d != 8 ?\n", len);
789				break;
790			}
791			musb_read_setup(musb, &setup);
792			retval = IRQ_HANDLED;
793
794			/* sometimes the RESET won't be reported */
795			if (unlikely(musb->g.speed == USB_SPEED_UNKNOWN)) {
796				u8	power;
797
798				printk(KERN_NOTICE "%s: peripheral reset "
799						"irq lost!\n",
800						musb_driver_name);
801				power = musb_readb(mbase, MUSB_POWER);
802				musb->g.speed = (power & MUSB_POWER_HSMODE)
803					? USB_SPEED_HIGH : USB_SPEED_FULL;
804
805			}
806
807			switch (musb->ep0_state) {
808
809			/* sequence #3 (no data stage), includes requests
810			 * we can't forward (notably SET_ADDRESS and the
811			 * device/endpoint feature set/clear operations)
812			 * plus SET_CONFIGURATION and others we must
813			 */
814			case MUSB_EP0_STAGE_ACKWAIT:
815				handled = service_zero_data_request(
816						musb, &setup);
817
818				/*
819				 * We're expecting no data in any case, so
820				 * always set the DATAEND bit -- doing this
821				 * here helps avoid SetupEnd interrupt coming
822				 * in the idle stage when we're stalling...
823				 */
824				musb->ackpend |= MUSB_CSR0_P_DATAEND;
825
826				/* status stage might be immediate */
827				if (handled > 0)
828					musb->ep0_state =
829						MUSB_EP0_STAGE_STATUSIN;
830				break;
831
832			/* sequence #1 (IN to host), includes GET_STATUS
833			 * requests that we can't forward, GET_DESCRIPTOR
834			 * and others that we must
835			 */
836			case MUSB_EP0_STAGE_TX:
837				handled = service_in_request(musb, &setup);
838				if (handled > 0) {
839					musb->ackpend = MUSB_CSR0_TXPKTRDY
840						| MUSB_CSR0_P_DATAEND;
841					musb->ep0_state =
842						MUSB_EP0_STAGE_STATUSOUT;
843				}
844				break;
845
846			/* sequence #2 (OUT from host), always forward */
847			default:		/* MUSB_EP0_STAGE_RX */
848				break;
849			}
850
851			DBG(3, "handled %d, csr %04x, ep0stage %s\n",
852				handled, csr,
853				decode_ep0stage(musb->ep0_state));
854
855			/* unless we need to delegate this to the gadget
856			 * driver, we know how to wrap this up:  csr0 has
857			 * not yet been written.
858			 */
859			if (handled < 0)
860				goto stall;
861			else if (handled > 0)
862				goto finish;
863
864			handled = forward_to_driver(musb, &setup);
865			if (handled < 0) {
866				musb_ep_select(mbase, 0);
867stall:
868				DBG(3, "stall (%d)\n", handled);
869				musb->ackpend |= MUSB_CSR0_P_SENDSTALL;
870				musb->ep0_state = MUSB_EP0_STAGE_IDLE;
871finish:
872				musb_writew(regs, MUSB_CSR0,
873						musb->ackpend);
874				musb->ackpend = 0;
875			}
876		}
877		break;
878
879	case MUSB_EP0_STAGE_ACKWAIT:
880		/* This should not happen. But happens with tusb6010 with
881		 * g_file_storage and high speed. Do nothing.
882		 */
883		retval = IRQ_HANDLED;
884		break;
885
886	default:
887		/* "can't happen" */
888		WARN_ON(1);
889		musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SENDSTALL);
890		musb->ep0_state = MUSB_EP0_STAGE_IDLE;
891		break;
892	}
893
894	return retval;
895}
896
897
898static int
899musb_g_ep0_enable(struct usb_ep *ep, const struct usb_endpoint_descriptor *desc)
900{
901	/* always enabled */
902	return -EINVAL;
903}
904
905static int musb_g_ep0_disable(struct usb_ep *e)
906{
907	/* always enabled */
908	return -EINVAL;
909}
910
911static int
912musb_g_ep0_queue(struct usb_ep *e, struct usb_request *r, gfp_t gfp_flags)
913{
914	struct musb_ep		*ep;
915	struct musb_request	*req;
916	struct musb		*musb;
917	int			status;
918	unsigned long		lockflags;
919	void __iomem		*regs;
920
921	if (!e || !r)
922		return -EINVAL;
923
924	ep = to_musb_ep(e);
925	musb = ep->musb;
926	regs = musb->control_ep->regs;
927
928	req = to_musb_request(r);
929	req->musb = musb;
930	req->request.actual = 0;
931	req->request.status = -EINPROGRESS;
932	req->tx = ep->is_in;
933
934	spin_lock_irqsave(&musb->lock, lockflags);
935
936	if (!list_empty(&ep->req_list)) {
937		status = -EBUSY;
938		goto cleanup;
939	}
940
941	switch (musb->ep0_state) {
942	case MUSB_EP0_STAGE_RX:		/* control-OUT data */
943	case MUSB_EP0_STAGE_TX:		/* control-IN data */
944	case MUSB_EP0_STAGE_ACKWAIT:	/* zero-length data */
945		status = 0;
946		break;
947	default:
948		DBG(1, "ep0 request queued in state %d\n",
949				musb->ep0_state);
950		status = -EINVAL;
951		goto cleanup;
952	}
953
954	/* add request to the list */
955	list_add_tail(&(req->request.list), &(ep->req_list));
956
957	DBG(3, "queue to %s (%s), length=%d\n",
958			ep->name, ep->is_in ? "IN/TX" : "OUT/RX",
959			req->request.length);
960
961	musb_ep_select(musb->mregs, 0);
962
963	/* sequence #1, IN ... start writing the data */
964	if (musb->ep0_state == MUSB_EP0_STAGE_TX)
965		ep0_txstate(musb);
966
967	/* sequence #3, no-data ... issue IN status */
968	else if (musb->ep0_state == MUSB_EP0_STAGE_ACKWAIT) {
969		if (req->request.length)
970			status = -EINVAL;
971		else {
972			musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
973			musb_writew(regs, MUSB_CSR0,
974					musb->ackpend | MUSB_CSR0_P_DATAEND);
975			musb->ackpend = 0;
976			musb_g_ep0_giveback(ep->musb, r);
977		}
978
979	/* else for sequence #2 (OUT), caller provides a buffer
980	 * before the next packet arrives.  deferred responses
981	 * (after SETUP is acked) are racey.
982	 */
983	} else if (musb->ackpend) {
984		musb_writew(regs, MUSB_CSR0, musb->ackpend);
985		musb->ackpend = 0;
986	}
987
988cleanup:
989	spin_unlock_irqrestore(&musb->lock, lockflags);
990	return status;
991}
992
993static int musb_g_ep0_dequeue(struct usb_ep *ep, struct usb_request *req)
994{
995	/* we just won't support this */
996	return -EINVAL;
997}
998
999static int musb_g_ep0_halt(struct usb_ep *e, int value)
1000{
1001	struct musb_ep		*ep;
1002	struct musb		*musb;
1003	void __iomem		*base, *regs;
1004	unsigned long		flags;
1005	int			status;
1006	u16			csr;
1007
1008	if (!e || !value)
1009		return -EINVAL;
1010
1011	ep = to_musb_ep(e);
1012	musb = ep->musb;
1013	base = musb->mregs;
1014	regs = musb->control_ep->regs;
1015	status = 0;
1016
1017	spin_lock_irqsave(&musb->lock, flags);
1018
1019	if (!list_empty(&ep->req_list)) {
1020		status = -EBUSY;
1021		goto cleanup;
1022	}
1023
1024	musb_ep_select(base, 0);
1025	csr = musb->ackpend;
1026
1027	switch (musb->ep0_state) {
1028
1029	/* Stalls are usually issued after parsing SETUP packet, either
1030	 * directly in irq context from setup() or else later.
1031	 */
1032	case MUSB_EP0_STAGE_TX:		/* control-IN data */
1033	case MUSB_EP0_STAGE_ACKWAIT:	/* STALL for zero-length data */
1034	case MUSB_EP0_STAGE_RX:		/* control-OUT data */
1035		csr = musb_readw(regs, MUSB_CSR0);
1036		/* FALLTHROUGH */
1037
1038	/* It's also OK to issue stalls during callbacks when a non-empty
1039	 * DATA stage buffer has been read (or even written).
1040	 */
1041	case MUSB_EP0_STAGE_STATUSIN:	/* control-OUT status */
1042	case MUSB_EP0_STAGE_STATUSOUT:	/* control-IN status */
1043
1044		csr |= MUSB_CSR0_P_SENDSTALL;
1045		musb_writew(regs, MUSB_CSR0, csr);
1046		musb->ep0_state = MUSB_EP0_STAGE_IDLE;
1047		musb->ackpend = 0;
1048		break;
1049	default:
1050		DBG(1, "ep0 can't halt in state %d\n", musb->ep0_state);
1051		status = -EINVAL;
1052	}
1053
1054cleanup:
1055	spin_unlock_irqrestore(&musb->lock, flags);
1056	return status;
1057}
1058
1059const struct usb_ep_ops musb_g_ep0_ops = {
1060	.enable		= musb_g_ep0_enable,
1061	.disable	= musb_g_ep0_disable,
1062	.alloc_request	= musb_alloc_request,
1063	.free_request	= musb_free_request,
1064	.queue		= musb_g_ep0_queue,
1065	.dequeue	= musb_g_ep0_dequeue,
1066	.set_halt	= musb_g_ep0_halt,
1067};
1068