1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * MUSB OTG peripheral driver ep0 handling
4 *
5 * Copyright 2005 Mentor Graphics Corporation
6 * Copyright (C) 2005-2006 by Texas Instruments
7 * Copyright (C) 2006-2007 Nokia Corporation
8 * Copyright (C) 2008-2009 MontaVista Software, Inc. <source@mvista.com>
9 */
10
11 #include <linux/kernel.h>
12 #include <linux/list.h>
13 #include <linux/timer.h>
14 #include <linux/spinlock.h>
15 #include <linux/device.h>
16 #include <linux/interrupt.h>
17
18 #include "musb_core.h"
19
20 /* ep0 is always musb->endpoints[0].ep_in */
21 #define next_ep0_request(musb) next_in_request(&(musb)->endpoints[0])
22
23 /*
24 * locking note: we use only the controller lock, for simpler correctness.
25 * It's always held with IRQs blocked.
26 *
27 * It protects the ep0 request queue as well as ep0_state, not just the
28 * controller and indexed registers. And that lock stays held unless it
29 * needs to be dropped to allow reentering this driver ... like upcalls to
30 * the gadget driver, or adjusting endpoint halt status.
31 */
32
decode_ep0stage(u8 stage)33 static char *decode_ep0stage(u8 stage)
34 {
35 switch (stage) {
36 case MUSB_EP0_STAGE_IDLE: return "idle";
37 case MUSB_EP0_STAGE_SETUP: return "setup";
38 case MUSB_EP0_STAGE_TX: return "in";
39 case MUSB_EP0_STAGE_RX: return "out";
40 case MUSB_EP0_STAGE_ACKWAIT: return "wait";
41 case MUSB_EP0_STAGE_STATUSIN: return "in/status";
42 case MUSB_EP0_STAGE_STATUSOUT: return "out/status";
43 default: return "?";
44 }
45 }
46
47 /* handle a standard GET_STATUS request
48 * Context: caller holds controller lock
49 */
service_tx_status_request(struct musb * musb,const struct usb_ctrlrequest * ctrlrequest)50 static int service_tx_status_request(
51 struct musb *musb,
52 const struct usb_ctrlrequest *ctrlrequest)
53 {
54 void __iomem *mbase = musb->mregs;
55 int handled = 1;
56 u8 result[2], epnum = 0;
57 const u8 recip = ctrlrequest->bRequestType & USB_RECIP_MASK;
58
59 result[1] = 0;
60
61 switch (recip) {
62 case USB_RECIP_DEVICE:
63 result[0] = musb->g.is_selfpowered << USB_DEVICE_SELF_POWERED;
64 result[0] |= musb->may_wakeup << USB_DEVICE_REMOTE_WAKEUP;
65 if (musb->g.is_otg) {
66 result[0] |= musb->g.b_hnp_enable
67 << USB_DEVICE_B_HNP_ENABLE;
68 result[0] |= musb->g.a_alt_hnp_support
69 << USB_DEVICE_A_ALT_HNP_SUPPORT;
70 result[0] |= musb->g.a_hnp_support
71 << USB_DEVICE_A_HNP_SUPPORT;
72 }
73 break;
74
75 case USB_RECIP_INTERFACE:
76 result[0] = 0;
77 break;
78
79 case USB_RECIP_ENDPOINT: {
80 int is_in;
81 struct musb_ep *ep;
82 u16 tmp;
83 void __iomem *regs;
84
85 epnum = (u8) ctrlrequest->wIndex;
86 if (!epnum) {
87 result[0] = 0;
88 break;
89 }
90
91 is_in = epnum & USB_DIR_IN;
92 epnum &= 0x0f;
93 if (epnum >= MUSB_C_NUM_EPS) {
94 handled = -EINVAL;
95 break;
96 }
97
98 if (is_in)
99 ep = &musb->endpoints[epnum].ep_in;
100 else
101 ep = &musb->endpoints[epnum].ep_out;
102 regs = musb->endpoints[epnum].regs;
103
104 if (!ep->desc) {
105 handled = -EINVAL;
106 break;
107 }
108
109 musb_ep_select(mbase, epnum);
110 if (is_in)
111 tmp = musb_readw(regs, MUSB_TXCSR)
112 & MUSB_TXCSR_P_SENDSTALL;
113 else
114 tmp = musb_readw(regs, MUSB_RXCSR)
115 & MUSB_RXCSR_P_SENDSTALL;
116 musb_ep_select(mbase, 0);
117
118 result[0] = tmp ? 1 : 0;
119 } break;
120
121 default:
122 /* class, vendor, etc ... delegate */
123 handled = 0;
124 break;
125 }
126
127 /* fill up the fifo; caller updates csr0 */
128 if (handled > 0) {
129 u16 len = le16_to_cpu(ctrlrequest->wLength);
130
131 if (len > 2)
132 len = 2;
133 musb_write_fifo(&musb->endpoints[0], len, result);
134 }
135
136 return handled;
137 }
138
139 /*
140 * handle a control-IN request, the end0 buffer contains the current request
141 * that is supposed to be a standard control request. Assumes the fifo to
142 * be at least 2 bytes long.
143 *
144 * @return 0 if the request was NOT HANDLED,
145 * < 0 when error
146 * > 0 when the request is processed
147 *
148 * Context: caller holds controller lock
149 */
150 static int
service_in_request(struct musb * musb,const struct usb_ctrlrequest * ctrlrequest)151 service_in_request(struct musb *musb, const struct usb_ctrlrequest *ctrlrequest)
152 {
153 int handled = 0; /* not handled */
154
155 if ((ctrlrequest->bRequestType & USB_TYPE_MASK)
156 == USB_TYPE_STANDARD) {
157 switch (ctrlrequest->bRequest) {
158 case USB_REQ_GET_STATUS:
159 handled = service_tx_status_request(musb,
160 ctrlrequest);
161 break;
162
163 /* case USB_REQ_SYNC_FRAME: */
164
165 default:
166 break;
167 }
168 }
169 return handled;
170 }
171
172 /*
173 * Context: caller holds controller lock
174 */
musb_g_ep0_giveback(struct musb * musb,struct usb_request * req)175 static void musb_g_ep0_giveback(struct musb *musb, struct usb_request *req)
176 {
177 musb_g_giveback(&musb->endpoints[0].ep_in, req, 0);
178 }
179
180 /*
181 * Tries to start B-device HNP negotiation if enabled via sysfs
182 */
musb_try_b_hnp_enable(struct musb * musb)183 static inline void musb_try_b_hnp_enable(struct musb *musb)
184 {
185 void __iomem *mbase = musb->mregs;
186 u8 devctl;
187
188 musb_dbg(musb, "HNP: Setting HR");
189 devctl = musb_readb(mbase, MUSB_DEVCTL);
190 musb_writeb(mbase, MUSB_DEVCTL, devctl | MUSB_DEVCTL_HR);
191 }
192
193 /*
194 * Handle all control requests with no DATA stage, including standard
195 * requests such as:
196 * USB_REQ_SET_CONFIGURATION, USB_REQ_SET_INTERFACE, unrecognized
197 * always delegated to the gadget driver
198 * USB_REQ_SET_ADDRESS, USB_REQ_CLEAR_FEATURE, USB_REQ_SET_FEATURE
199 * always handled here, except for class/vendor/... features
200 *
201 * Context: caller holds controller lock
202 */
203 static int
service_zero_data_request(struct musb * musb,struct usb_ctrlrequest * ctrlrequest)204 service_zero_data_request(struct musb *musb,
205 struct usb_ctrlrequest *ctrlrequest)
206 __releases(musb->lock)
207 __acquires(musb->lock)
208 {
209 int handled = -EINVAL;
210 void __iomem *mbase = musb->mregs;
211 const u8 recip = ctrlrequest->bRequestType & USB_RECIP_MASK;
212
213 /* the gadget driver handles everything except what we MUST handle */
214 if ((ctrlrequest->bRequestType & USB_TYPE_MASK)
215 == USB_TYPE_STANDARD) {
216 switch (ctrlrequest->bRequest) {
217 case USB_REQ_SET_ADDRESS:
218 /* change it after the status stage */
219 musb->set_address = true;
220 musb->address = (u8) (ctrlrequest->wValue & 0x7f);
221 handled = 1;
222 break;
223
224 case USB_REQ_CLEAR_FEATURE:
225 switch (recip) {
226 case USB_RECIP_DEVICE:
227 if (ctrlrequest->wValue
228 != USB_DEVICE_REMOTE_WAKEUP)
229 break;
230 musb->may_wakeup = 0;
231 handled = 1;
232 break;
233 case USB_RECIP_INTERFACE:
234 break;
235 case USB_RECIP_ENDPOINT:{
236 const u8 epnum =
237 ctrlrequest->wIndex & 0x0f;
238 struct musb_ep *musb_ep;
239 struct musb_hw_ep *ep;
240 struct musb_request *request;
241 void __iomem *regs;
242 int is_in;
243 u16 csr;
244
245 if (epnum == 0 || epnum >= MUSB_C_NUM_EPS ||
246 ctrlrequest->wValue != USB_ENDPOINT_HALT)
247 break;
248
249 ep = musb->endpoints + epnum;
250 regs = ep->regs;
251 is_in = ctrlrequest->wIndex & USB_DIR_IN;
252 if (is_in)
253 musb_ep = &ep->ep_in;
254 else
255 musb_ep = &ep->ep_out;
256 if (!musb_ep->desc)
257 break;
258
259 handled = 1;
260 /* Ignore request if endpoint is wedged */
261 if (musb_ep->wedged)
262 break;
263
264 musb_ep_select(mbase, epnum);
265 if (is_in) {
266 csr = musb_readw(regs, MUSB_TXCSR);
267 csr |= MUSB_TXCSR_CLRDATATOG |
268 MUSB_TXCSR_P_WZC_BITS;
269 csr &= ~(MUSB_TXCSR_P_SENDSTALL |
270 MUSB_TXCSR_P_SENTSTALL |
271 MUSB_TXCSR_TXPKTRDY);
272 musb_writew(regs, MUSB_TXCSR, csr);
273 } else {
274 csr = musb_readw(regs, MUSB_RXCSR);
275 csr |= MUSB_RXCSR_CLRDATATOG |
276 MUSB_RXCSR_P_WZC_BITS;
277 csr &= ~(MUSB_RXCSR_P_SENDSTALL |
278 MUSB_RXCSR_P_SENTSTALL);
279 musb_writew(regs, MUSB_RXCSR, csr);
280 }
281
282 /* Maybe start the first request in the queue */
283 request = next_request(musb_ep);
284 if (!musb_ep->busy && request) {
285 musb_dbg(musb, "restarting the request");
286 musb_ep_restart(musb, request);
287 }
288
289 /* select ep0 again */
290 musb_ep_select(mbase, 0);
291 } break;
292 default:
293 /* class, vendor, etc ... delegate */
294 handled = 0;
295 break;
296 }
297 break;
298
299 case USB_REQ_SET_FEATURE:
300 switch (recip) {
301 case USB_RECIP_DEVICE:
302 handled = 1;
303 switch (ctrlrequest->wValue) {
304 case USB_DEVICE_REMOTE_WAKEUP:
305 musb->may_wakeup = 1;
306 break;
307 case USB_DEVICE_TEST_MODE:
308 if (musb->g.speed != USB_SPEED_HIGH)
309 goto stall;
310 if (ctrlrequest->wIndex & 0xff)
311 goto stall;
312
313 switch (ctrlrequest->wIndex >> 8) {
314 case USB_TEST_J:
315 pr_debug("USB_TEST_J\n");
316 musb->test_mode_nr =
317 MUSB_TEST_J;
318 break;
319 case USB_TEST_K:
320 pr_debug("USB_TEST_K\n");
321 musb->test_mode_nr =
322 MUSB_TEST_K;
323 break;
324 case USB_TEST_SE0_NAK:
325 pr_debug("USB_TEST_SE0_NAK\n");
326 musb->test_mode_nr =
327 MUSB_TEST_SE0_NAK;
328 break;
329 case USB_TEST_PACKET:
330 pr_debug("USB_TEST_PACKET\n");
331 musb->test_mode_nr =
332 MUSB_TEST_PACKET;
333 break;
334
335 case 0xc0:
336 /* TEST_FORCE_HS */
337 pr_debug("TEST_FORCE_HS\n");
338 musb->test_mode_nr =
339 MUSB_TEST_FORCE_HS;
340 break;
341 case 0xc1:
342 /* TEST_FORCE_FS */
343 pr_debug("TEST_FORCE_FS\n");
344 musb->test_mode_nr =
345 MUSB_TEST_FORCE_FS;
346 break;
347 case 0xc2:
348 /* TEST_FIFO_ACCESS */
349 pr_debug("TEST_FIFO_ACCESS\n");
350 musb->test_mode_nr =
351 MUSB_TEST_FIFO_ACCESS;
352 break;
353 case 0xc3:
354 /* TEST_FORCE_HOST */
355 pr_debug("TEST_FORCE_HOST\n");
356 musb->test_mode_nr =
357 MUSB_TEST_FORCE_HOST;
358 break;
359 default:
360 goto stall;
361 }
362
363 /* enter test mode after irq */
364 if (handled > 0)
365 musb->test_mode = true;
366 break;
367 case USB_DEVICE_B_HNP_ENABLE:
368 if (!musb->g.is_otg)
369 goto stall;
370 musb->g.b_hnp_enable = 1;
371 musb_try_b_hnp_enable(musb);
372 break;
373 case USB_DEVICE_A_HNP_SUPPORT:
374 if (!musb->g.is_otg)
375 goto stall;
376 musb->g.a_hnp_support = 1;
377 break;
378 case USB_DEVICE_A_ALT_HNP_SUPPORT:
379 if (!musb->g.is_otg)
380 goto stall;
381 musb->g.a_alt_hnp_support = 1;
382 break;
383 case USB_DEVICE_DEBUG_MODE:
384 handled = 0;
385 break;
386 stall:
387 default:
388 handled = -EINVAL;
389 break;
390 }
391 break;
392
393 case USB_RECIP_INTERFACE:
394 break;
395
396 case USB_RECIP_ENDPOINT:{
397 const u8 epnum =
398 ctrlrequest->wIndex & 0x0f;
399 struct musb_ep *musb_ep;
400 struct musb_hw_ep *ep;
401 void __iomem *regs;
402 int is_in;
403 u16 csr;
404
405 if (epnum == 0 || epnum >= MUSB_C_NUM_EPS ||
406 ctrlrequest->wValue != USB_ENDPOINT_HALT)
407 break;
408
409 ep = musb->endpoints + epnum;
410 regs = ep->regs;
411 is_in = ctrlrequest->wIndex & USB_DIR_IN;
412 if (is_in)
413 musb_ep = &ep->ep_in;
414 else
415 musb_ep = &ep->ep_out;
416 if (!musb_ep->desc)
417 break;
418
419 musb_ep_select(mbase, epnum);
420 if (is_in) {
421 csr = musb_readw(regs, MUSB_TXCSR);
422 if (csr & MUSB_TXCSR_FIFONOTEMPTY)
423 csr |= MUSB_TXCSR_FLUSHFIFO;
424 csr |= MUSB_TXCSR_P_SENDSTALL
425 | MUSB_TXCSR_CLRDATATOG
426 | MUSB_TXCSR_P_WZC_BITS;
427 musb_writew(regs, MUSB_TXCSR, csr);
428 } else {
429 csr = musb_readw(regs, MUSB_RXCSR);
430 csr |= MUSB_RXCSR_P_SENDSTALL
431 | MUSB_RXCSR_FLUSHFIFO
432 | MUSB_RXCSR_CLRDATATOG
433 | MUSB_RXCSR_P_WZC_BITS;
434 musb_writew(regs, MUSB_RXCSR, csr);
435 }
436
437 /* select ep0 again */
438 musb_ep_select(mbase, 0);
439 handled = 1;
440 } break;
441
442 default:
443 /* class, vendor, etc ... delegate */
444 handled = 0;
445 break;
446 }
447 break;
448 default:
449 /* delegate SET_CONFIGURATION, etc */
450 handled = 0;
451 }
452 } else
453 handled = 0;
454 return handled;
455 }
456
457 /* we have an ep0out data packet
458 * Context: caller holds controller lock
459 */
ep0_rxstate(struct musb * musb)460 static void ep0_rxstate(struct musb *musb)
461 {
462 void __iomem *regs = musb->control_ep->regs;
463 struct musb_request *request;
464 struct usb_request *req;
465 u16 count, csr;
466
467 request = next_ep0_request(musb);
468 req = &request->request;
469
470 /* read packet and ack; or stall because of gadget driver bug:
471 * should have provided the rx buffer before setup() returned.
472 */
473 if (req) {
474 void *buf = req->buf + req->actual;
475 unsigned len = req->length - req->actual;
476
477 /* read the buffer */
478 count = musb_readb(regs, MUSB_COUNT0);
479 if (count > len) {
480 req->status = -EOVERFLOW;
481 count = len;
482 }
483 if (count > 0) {
484 musb_read_fifo(&musb->endpoints[0], count, buf);
485 req->actual += count;
486 }
487 csr = MUSB_CSR0_P_SVDRXPKTRDY;
488 if (count < 64 || req->actual == req->length) {
489 musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
490 csr |= MUSB_CSR0_P_DATAEND;
491 } else
492 req = NULL;
493 } else
494 csr = MUSB_CSR0_P_SVDRXPKTRDY | MUSB_CSR0_P_SENDSTALL;
495
496
497 /* Completion handler may choose to stall, e.g. because the
498 * message just received holds invalid data.
499 */
500 if (req) {
501 musb->ackpend = csr;
502 musb_g_ep0_giveback(musb, req);
503 if (!musb->ackpend)
504 return;
505 musb->ackpend = 0;
506 }
507 musb_ep_select(musb->mregs, 0);
508 musb_writew(regs, MUSB_CSR0, csr);
509 }
510
511 /*
512 * transmitting to the host (IN), this code might be called from IRQ
513 * and from kernel thread.
514 *
515 * Context: caller holds controller lock
516 */
ep0_txstate(struct musb * musb)517 static void ep0_txstate(struct musb *musb)
518 {
519 void __iomem *regs = musb->control_ep->regs;
520 struct musb_request *req = next_ep0_request(musb);
521 struct usb_request *request;
522 u16 csr = MUSB_CSR0_TXPKTRDY;
523 u8 *fifo_src;
524 u8 fifo_count;
525
526 if (!req) {
527 /* WARN_ON(1); */
528 musb_dbg(musb, "odd; csr0 %04x", musb_readw(regs, MUSB_CSR0));
529 return;
530 }
531
532 request = &req->request;
533
534 /* load the data */
535 fifo_src = (u8 *) request->buf + request->actual;
536 fifo_count = min((unsigned) MUSB_EP0_FIFOSIZE,
537 request->length - request->actual);
538 musb_write_fifo(&musb->endpoints[0], fifo_count, fifo_src);
539 request->actual += fifo_count;
540
541 /* update the flags */
542 if (fifo_count < MUSB_MAX_END0_PACKET
543 || (request->actual == request->length
544 && !request->zero)) {
545 musb->ep0_state = MUSB_EP0_STAGE_STATUSOUT;
546 csr |= MUSB_CSR0_P_DATAEND;
547 } else
548 request = NULL;
549
550 /* report completions as soon as the fifo's loaded; there's no
551 * win in waiting till this last packet gets acked. (other than
552 * very precise fault reporting, needed by USB TMC; possible with
553 * this hardware, but not usable from portable gadget drivers.)
554 */
555 if (request) {
556 musb->ackpend = csr;
557 musb_g_ep0_giveback(musb, request);
558 if (!musb->ackpend)
559 return;
560 musb->ackpend = 0;
561 }
562
563 /* send it out, triggering a "txpktrdy cleared" irq */
564 musb_ep_select(musb->mregs, 0);
565 musb_writew(regs, MUSB_CSR0, csr);
566 }
567
568 /*
569 * Read a SETUP packet (struct usb_ctrlrequest) from the hardware.
570 * Fields are left in USB byte-order.
571 *
572 * Context: caller holds controller lock.
573 */
574 static void
musb_read_setup(struct musb * musb,struct usb_ctrlrequest * req)575 musb_read_setup(struct musb *musb, struct usb_ctrlrequest *req)
576 {
577 struct musb_request *r;
578 void __iomem *regs = musb->control_ep->regs;
579
580 musb_read_fifo(&musb->endpoints[0], sizeof *req, (u8 *)req);
581
582 /* NOTE: earlier 2.6 versions changed setup packets to host
583 * order, but now USB packets always stay in USB byte order.
584 */
585 musb_dbg(musb, "SETUP req%02x.%02x v%04x i%04x l%d",
586 req->bRequestType,
587 req->bRequest,
588 le16_to_cpu(req->wValue),
589 le16_to_cpu(req->wIndex),
590 le16_to_cpu(req->wLength));
591
592 /* clean up any leftover transfers */
593 r = next_ep0_request(musb);
594 if (r)
595 musb_g_ep0_giveback(musb, &r->request);
596
597 /* For zero-data requests we want to delay the STATUS stage to
598 * avoid SETUPEND errors. If we read data (OUT), delay accepting
599 * packets until there's a buffer to store them in.
600 *
601 * If we write data, the controller acts happier if we enable
602 * the TX FIFO right away, and give the controller a moment
603 * to switch modes...
604 */
605 musb->set_address = false;
606 musb->ackpend = MUSB_CSR0_P_SVDRXPKTRDY;
607 if (req->wLength == 0) {
608 if (req->bRequestType & USB_DIR_IN)
609 musb->ackpend |= MUSB_CSR0_TXPKTRDY;
610 musb->ep0_state = MUSB_EP0_STAGE_ACKWAIT;
611 } else if (req->bRequestType & USB_DIR_IN) {
612 musb->ep0_state = MUSB_EP0_STAGE_TX;
613 musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SVDRXPKTRDY);
614 while ((musb_readw(regs, MUSB_CSR0)
615 & MUSB_CSR0_RXPKTRDY) != 0)
616 cpu_relax();
617 musb->ackpend = 0;
618 } else
619 musb->ep0_state = MUSB_EP0_STAGE_RX;
620 }
621
622 static int
forward_to_driver(struct musb * musb,const struct usb_ctrlrequest * ctrlrequest)623 forward_to_driver(struct musb *musb, const struct usb_ctrlrequest *ctrlrequest)
624 __releases(musb->lock)
625 __acquires(musb->lock)
626 {
627 int retval;
628 if (!musb->gadget_driver)
629 return -EOPNOTSUPP;
630 spin_unlock(&musb->lock);
631 retval = musb->gadget_driver->setup(&musb->g, ctrlrequest);
632 spin_lock(&musb->lock);
633 return retval;
634 }
635
636 /*
637 * Handle peripheral ep0 interrupt
638 *
639 * Context: irq handler; we won't re-enter the driver that way.
640 */
musb_g_ep0_irq(struct musb * musb)641 irqreturn_t musb_g_ep0_irq(struct musb *musb)
642 {
643 u16 csr;
644 u16 len;
645 void __iomem *mbase = musb->mregs;
646 void __iomem *regs = musb->endpoints[0].regs;
647 irqreturn_t retval = IRQ_NONE;
648
649 musb_ep_select(mbase, 0); /* select ep0 */
650 csr = musb_readw(regs, MUSB_CSR0);
651 len = musb_readb(regs, MUSB_COUNT0);
652
653 musb_dbg(musb, "csr %04x, count %d, ep0stage %s",
654 csr, len, decode_ep0stage(musb->ep0_state));
655
656 if (csr & MUSB_CSR0_P_DATAEND) {
657 /*
658 * If DATAEND is set we should not call the callback,
659 * hence the status stage is not complete.
660 */
661 return IRQ_HANDLED;
662 }
663
664 /* I sent a stall.. need to acknowledge it now.. */
665 if (csr & MUSB_CSR0_P_SENTSTALL) {
666 musb_writew(regs, MUSB_CSR0,
667 csr & ~MUSB_CSR0_P_SENTSTALL);
668 retval = IRQ_HANDLED;
669 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
670 csr = musb_readw(regs, MUSB_CSR0);
671 }
672
673 /* request ended "early" */
674 if (csr & MUSB_CSR0_P_SETUPEND) {
675 musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SVDSETUPEND);
676 retval = IRQ_HANDLED;
677 /* Transition into the early status phase */
678 switch (musb->ep0_state) {
679 case MUSB_EP0_STAGE_TX:
680 musb->ep0_state = MUSB_EP0_STAGE_STATUSOUT;
681 break;
682 case MUSB_EP0_STAGE_RX:
683 musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
684 break;
685 default:
686 ERR("SetupEnd came in a wrong ep0stage %s\n",
687 decode_ep0stage(musb->ep0_state));
688 }
689 csr = musb_readw(regs, MUSB_CSR0);
690 /* NOTE: request may need completion */
691 }
692
693 /* docs from Mentor only describe tx, rx, and idle/setup states.
694 * we need to handle nuances around status stages, and also the
695 * case where status and setup stages come back-to-back ...
696 */
697 switch (musb->ep0_state) {
698
699 case MUSB_EP0_STAGE_TX:
700 /* irq on clearing txpktrdy */
701 if ((csr & MUSB_CSR0_TXPKTRDY) == 0) {
702 ep0_txstate(musb);
703 retval = IRQ_HANDLED;
704 }
705 break;
706
707 case MUSB_EP0_STAGE_RX:
708 /* irq on set rxpktrdy */
709 if (csr & MUSB_CSR0_RXPKTRDY) {
710 ep0_rxstate(musb);
711 retval = IRQ_HANDLED;
712 }
713 break;
714
715 case MUSB_EP0_STAGE_STATUSIN:
716 /* end of sequence #2 (OUT/RX state) or #3 (no data) */
717
718 /* update address (if needed) only @ the end of the
719 * status phase per usb spec, which also guarantees
720 * we get 10 msec to receive this irq... until this
721 * is done we won't see the next packet.
722 */
723 if (musb->set_address) {
724 musb->set_address = false;
725 musb_writeb(mbase, MUSB_FADDR, musb->address);
726 }
727
728 /* enter test mode if needed (exit by reset) */
729 else if (musb->test_mode) {
730 musb_dbg(musb, "entering TESTMODE");
731
732 if (MUSB_TEST_PACKET == musb->test_mode_nr)
733 musb_load_testpacket(musb);
734
735 musb_writeb(mbase, MUSB_TESTMODE,
736 musb->test_mode_nr);
737 }
738 fallthrough;
739
740 case MUSB_EP0_STAGE_STATUSOUT:
741 /* end of sequence #1: write to host (TX state) */
742 {
743 struct musb_request *req;
744
745 req = next_ep0_request(musb);
746 if (req)
747 musb_g_ep0_giveback(musb, &req->request);
748 }
749
750 /*
751 * In case when several interrupts can get coalesced,
752 * check to see if we've already received a SETUP packet...
753 */
754 if (csr & MUSB_CSR0_RXPKTRDY)
755 goto setup;
756
757 retval = IRQ_HANDLED;
758 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
759 break;
760
761 case MUSB_EP0_STAGE_IDLE:
762 /*
763 * This state is typically (but not always) indiscernible
764 * from the status states since the corresponding interrupts
765 * tend to happen within too little period of time (with only
766 * a zero-length packet in between) and so get coalesced...
767 */
768 retval = IRQ_HANDLED;
769 musb->ep0_state = MUSB_EP0_STAGE_SETUP;
770 fallthrough;
771
772 case MUSB_EP0_STAGE_SETUP:
773 setup:
774 if (csr & MUSB_CSR0_RXPKTRDY) {
775 struct usb_ctrlrequest setup;
776 int handled = 0;
777
778 if (len != 8) {
779 ERR("SETUP packet len %d != 8 ?\n", len);
780 break;
781 }
782 musb_read_setup(musb, &setup);
783 retval = IRQ_HANDLED;
784
785 /* sometimes the RESET won't be reported */
786 if (unlikely(musb->g.speed == USB_SPEED_UNKNOWN)) {
787 u8 power;
788
789 printk(KERN_NOTICE "%s: peripheral reset "
790 "irq lost!\n",
791 musb_driver_name);
792 power = musb_readb(mbase, MUSB_POWER);
793 musb->g.speed = (power & MUSB_POWER_HSMODE)
794 ? USB_SPEED_HIGH : USB_SPEED_FULL;
795
796 }
797
798 switch (musb->ep0_state) {
799
800 /* sequence #3 (no data stage), includes requests
801 * we can't forward (notably SET_ADDRESS and the
802 * device/endpoint feature set/clear operations)
803 * plus SET_CONFIGURATION and others we must
804 */
805 case MUSB_EP0_STAGE_ACKWAIT:
806 handled = service_zero_data_request(
807 musb, &setup);
808
809 /*
810 * We're expecting no data in any case, so
811 * always set the DATAEND bit -- doing this
812 * here helps avoid SetupEnd interrupt coming
813 * in the idle stage when we're stalling...
814 */
815 musb->ackpend |= MUSB_CSR0_P_DATAEND;
816
817 /* status stage might be immediate */
818 if (handled > 0)
819 musb->ep0_state =
820 MUSB_EP0_STAGE_STATUSIN;
821 break;
822
823 /* sequence #1 (IN to host), includes GET_STATUS
824 * requests that we can't forward, GET_DESCRIPTOR
825 * and others that we must
826 */
827 case MUSB_EP0_STAGE_TX:
828 handled = service_in_request(musb, &setup);
829 if (handled > 0) {
830 musb->ackpend = MUSB_CSR0_TXPKTRDY
831 | MUSB_CSR0_P_DATAEND;
832 musb->ep0_state =
833 MUSB_EP0_STAGE_STATUSOUT;
834 }
835 break;
836
837 /* sequence #2 (OUT from host), always forward */
838 default: /* MUSB_EP0_STAGE_RX */
839 break;
840 }
841
842 musb_dbg(musb, "handled %d, csr %04x, ep0stage %s",
843 handled, csr,
844 decode_ep0stage(musb->ep0_state));
845
846 /* unless we need to delegate this to the gadget
847 * driver, we know how to wrap this up: csr0 has
848 * not yet been written.
849 */
850 if (handled < 0)
851 goto stall;
852 else if (handled > 0)
853 goto finish;
854
855 handled = forward_to_driver(musb, &setup);
856 if (handled < 0) {
857 musb_ep_select(mbase, 0);
858 stall:
859 musb_dbg(musb, "stall (%d)", handled);
860 musb->ackpend |= MUSB_CSR0_P_SENDSTALL;
861 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
862 finish:
863 musb_writew(regs, MUSB_CSR0,
864 musb->ackpend);
865 musb->ackpend = 0;
866 }
867 }
868 break;
869
870 case MUSB_EP0_STAGE_ACKWAIT:
871 /* This should not happen. But happens with tusb6010 with
872 * g_file_storage and high speed. Do nothing.
873 */
874 retval = IRQ_HANDLED;
875 break;
876
877 default:
878 /* "can't happen" */
879 WARN_ON(1);
880 musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SENDSTALL);
881 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
882 break;
883 }
884
885 return retval;
886 }
887
888
889 static int
musb_g_ep0_enable(struct usb_ep * ep,const struct usb_endpoint_descriptor * desc)890 musb_g_ep0_enable(struct usb_ep *ep, const struct usb_endpoint_descriptor *desc)
891 {
892 /* always enabled */
893 return -EINVAL;
894 }
895
musb_g_ep0_disable(struct usb_ep * e)896 static int musb_g_ep0_disable(struct usb_ep *e)
897 {
898 /* always enabled */
899 return -EINVAL;
900 }
901
902 static int
musb_g_ep0_queue(struct usb_ep * e,struct usb_request * r,gfp_t gfp_flags)903 musb_g_ep0_queue(struct usb_ep *e, struct usb_request *r, gfp_t gfp_flags)
904 {
905 struct musb_ep *ep;
906 struct musb_request *req;
907 struct musb *musb;
908 int status;
909 unsigned long lockflags;
910 void __iomem *regs;
911
912 if (!e || !r)
913 return -EINVAL;
914
915 ep = to_musb_ep(e);
916 musb = ep->musb;
917 regs = musb->control_ep->regs;
918
919 req = to_musb_request(r);
920 req->musb = musb;
921 req->request.actual = 0;
922 req->request.status = -EINPROGRESS;
923 req->tx = ep->is_in;
924
925 spin_lock_irqsave(&musb->lock, lockflags);
926
927 if (!list_empty(&ep->req_list)) {
928 status = -EBUSY;
929 goto cleanup;
930 }
931
932 switch (musb->ep0_state) {
933 case MUSB_EP0_STAGE_RX: /* control-OUT data */
934 case MUSB_EP0_STAGE_TX: /* control-IN data */
935 case MUSB_EP0_STAGE_ACKWAIT: /* zero-length data */
936 status = 0;
937 break;
938 default:
939 musb_dbg(musb, "ep0 request queued in state %d",
940 musb->ep0_state);
941 status = -EINVAL;
942 goto cleanup;
943 }
944
945 /* add request to the list */
946 list_add_tail(&req->list, &ep->req_list);
947
948 musb_dbg(musb, "queue to %s (%s), length=%d",
949 ep->name, ep->is_in ? "IN/TX" : "OUT/RX",
950 req->request.length);
951
952 musb_ep_select(musb->mregs, 0);
953
954 /* sequence #1, IN ... start writing the data */
955 if (musb->ep0_state == MUSB_EP0_STAGE_TX)
956 ep0_txstate(musb);
957
958 /* sequence #3, no-data ... issue IN status */
959 else if (musb->ep0_state == MUSB_EP0_STAGE_ACKWAIT) {
960 if (req->request.length)
961 status = -EINVAL;
962 else {
963 musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
964 musb_writew(regs, MUSB_CSR0,
965 musb->ackpend | MUSB_CSR0_P_DATAEND);
966 musb->ackpend = 0;
967 musb_g_ep0_giveback(ep->musb, r);
968 }
969
970 /* else for sequence #2 (OUT), caller provides a buffer
971 * before the next packet arrives. deferred responses
972 * (after SETUP is acked) are racey.
973 */
974 } else if (musb->ackpend) {
975 musb_writew(regs, MUSB_CSR0, musb->ackpend);
976 musb->ackpend = 0;
977 }
978
979 cleanup:
980 spin_unlock_irqrestore(&musb->lock, lockflags);
981 return status;
982 }
983
musb_g_ep0_dequeue(struct usb_ep * ep,struct usb_request * req)984 static int musb_g_ep0_dequeue(struct usb_ep *ep, struct usb_request *req)
985 {
986 /* we just won't support this */
987 return -EINVAL;
988 }
989
musb_g_ep0_halt(struct usb_ep * e,int value)990 static int musb_g_ep0_halt(struct usb_ep *e, int value)
991 {
992 struct musb_ep *ep;
993 struct musb *musb;
994 void __iomem *base, *regs;
995 unsigned long flags;
996 int status;
997 u16 csr;
998
999 if (!e || !value)
1000 return -EINVAL;
1001
1002 ep = to_musb_ep(e);
1003 musb = ep->musb;
1004 base = musb->mregs;
1005 regs = musb->control_ep->regs;
1006 status = 0;
1007
1008 spin_lock_irqsave(&musb->lock, flags);
1009
1010 if (!list_empty(&ep->req_list)) {
1011 status = -EBUSY;
1012 goto cleanup;
1013 }
1014
1015 musb_ep_select(base, 0);
1016 csr = musb->ackpend;
1017
1018 switch (musb->ep0_state) {
1019
1020 /* Stalls are usually issued after parsing SETUP packet, either
1021 * directly in irq context from setup() or else later.
1022 */
1023 case MUSB_EP0_STAGE_TX: /* control-IN data */
1024 case MUSB_EP0_STAGE_ACKWAIT: /* STALL for zero-length data */
1025 case MUSB_EP0_STAGE_RX: /* control-OUT data */
1026 csr = musb_readw(regs, MUSB_CSR0);
1027 fallthrough;
1028
1029 /* It's also OK to issue stalls during callbacks when a non-empty
1030 * DATA stage buffer has been read (or even written).
1031 */
1032 case MUSB_EP0_STAGE_STATUSIN: /* control-OUT status */
1033 case MUSB_EP0_STAGE_STATUSOUT: /* control-IN status */
1034
1035 csr |= MUSB_CSR0_P_SENDSTALL;
1036 musb_writew(regs, MUSB_CSR0, csr);
1037 musb->ep0_state = MUSB_EP0_STAGE_IDLE;
1038 musb->ackpend = 0;
1039 break;
1040 default:
1041 musb_dbg(musb, "ep0 can't halt in state %d", musb->ep0_state);
1042 status = -EINVAL;
1043 }
1044
1045 cleanup:
1046 spin_unlock_irqrestore(&musb->lock, flags);
1047 return status;
1048 }
1049
1050 const struct usb_ep_ops musb_g_ep0_ops = {
1051 .enable = musb_g_ep0_enable,
1052 .disable = musb_g_ep0_disable,
1053 .alloc_request = musb_alloc_request,
1054 .free_request = musb_free_request,
1055 .queue = musb_g_ep0_queue,
1056 .dequeue = musb_g_ep0_dequeue,
1057 .set_halt = musb_g_ep0_halt,
1058 };
1059