xref: /openbsd/sys/dev/usb/dwc2/dwc2_hcdqueue.c (revision 73471bf0)
1 /*	$OpenBSD: dwc2_hcdqueue.c,v 1.12 2021/09/04 10:19:28 mglocker Exp $	*/
2 /*	$NetBSD: dwc2_hcdqueue.c,v 1.11 2014/09/03 10:00:08 skrll Exp $	*/
3 
4 /*
5  * hcd_queue.c - DesignWare HS OTG Controller host queuing routines
6  *
7  * Copyright (C) 2004-2013 Synopsys, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions, and the following disclaimer,
14  *    without modification.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The names of the above-listed copyright holders may not be used
19  *    to endorse or promote products derived from this software without
20  *    specific prior written permission.
21  *
22  * ALTERNATIVELY, this software may be distributed under the terms of the
23  * GNU General Public License ("GPL") as published by the Free Software
24  * Foundation; either version 2 of the License, or (at your option) any
25  * later version.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
28  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
29  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
31  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
32  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
33  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
34  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
35  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
36  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
37  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * This file contains the functions to manage Queue Heads and Queue
42  * Transfer Descriptors for Host mode
43  */
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/malloc.h>
48 #include <sys/pool.h>
49 
50 #include <machine/bus.h>
51 
52 #include <dev/usb/usb.h>
53 #include <dev/usb/usbdi.h>
54 #include <dev/usb/usbdivar.h>
55 #include <dev/usb/usb_mem.h>
56 
57 #include <dev/usb/dwc2/dwc2.h>
58 #include <dev/usb/dwc2/dwc2var.h>
59 
60 #include <dev/usb/dwc2/dwc2_core.h>
61 #include <dev/usb/dwc2/dwc2_hcd.h>
62 
63 STATIC u32 dwc2_calc_bus_time(struct dwc2_hsotg *, int, int, int, int);
64 STATIC void dwc2_wait_timer_fn(void *);
65 
66 /* If we get a NAK, wait this long before retrying */
67 #define DWC2_RETRY_WAIT_DELAY 1	/* msec */
68 
69 /**
70  * dwc2_qh_init() - Initializes a QH structure
71  *
72  * @hsotg: The HCD state structure for the DWC OTG controller
73  * @qh:    The QH to init
74  * @urb:   Holds the information about the device/endpoint needed to initialize
75  *         the QH
76  */
77 #define SCHEDULE_SLOP 10
78 STATIC void dwc2_qh_init(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
79 			 struct dwc2_hcd_urb *urb)
80 {
81 	int dev_speed, hub_addr, hub_port;
82 
83 	dev_vdbg(hsotg->dev, "%s()\n", __func__);
84 
85 	/* Initialize QH */
86 	qh->hsotg = hsotg;
87 	/* XXX timer_setup(&qh->wait_timer, dwc2_wait_timer_fn, 0); */
88 	timeout_set(&qh->wait_timer, dwc2_wait_timer_fn, qh);
89 	qh->ep_type = dwc2_hcd_get_pipe_type(&urb->pipe_info);
90 	qh->ep_is_in = dwc2_hcd_is_pipe_in(&urb->pipe_info) ? 1 : 0;
91 
92 	qh->data_toggle = DWC2_HC_PID_DATA0;
93 	qh->maxp = dwc2_hcd_get_mps(&urb->pipe_info);
94 	INIT_LIST_HEAD(&qh->qtd_list);
95 	INIT_LIST_HEAD(&qh->qh_list_entry);
96 
97 	/* FS/LS Endpoint on HS Hub, NOT virtual root hub */
98 	dev_speed = dwc2_host_get_speed(hsotg, urb->priv);
99 
100 	dwc2_host_hub_info(hsotg, urb->priv, &hub_addr, &hub_port);
101 	qh->nak_frame = 0xffff;
102 
103 	if ((dev_speed == USB_SPEED_LOW || dev_speed == USB_SPEED_FULL) &&
104 	    hub_addr != 0 && hub_addr != 1) {
105 		dev_vdbg(hsotg->dev,
106 			 "QH init: EP %d: TT found at hub addr %d, for port %d\n",
107 			 dwc2_hcd_get_ep_num(&urb->pipe_info), hub_addr,
108 			 hub_port);
109 		qh->do_split = 1;
110 	}
111 
112 	if (qh->ep_type == USB_ENDPOINT_XFER_INT ||
113 	    qh->ep_type == USB_ENDPOINT_XFER_ISOC) {
114 		/* Compute scheduling parameters once and save them */
115 		u32 hprt, prtspd;
116 
117 		/* Todo: Account for split transfers in the bus time */
118 		int bytecount =
119 			dwc2_hb_mult(qh->maxp) * dwc2_max_packet(qh->maxp);
120 
121 		qh->usecs = dwc2_calc_bus_time(hsotg, qh->do_split ?
122 				USB_SPEED_HIGH : dev_speed, qh->ep_is_in,
123 				qh->ep_type == USB_ENDPOINT_XFER_ISOC,
124 				bytecount);
125 
126 		/* Ensure frame_number corresponds to the reality */
127 		hsotg->frame_number = dwc2_hcd_get_frame_number(hsotg);
128 		/* Start in a slightly future (micro)frame */
129 		qh->sched_frame = dwc2_frame_num_inc(hsotg->frame_number,
130 						     SCHEDULE_SLOP);
131 		qh->interval = urb->interval;
132 #if 0
133 		/* Increase interrupt polling rate for debugging */
134 		if (qh->ep_type == USB_ENDPOINT_XFER_INT)
135 			qh->interval = 8;
136 #endif
137 		hprt = DWC2_READ_4(hsotg, HPRT0);
138 		prtspd = (hprt & HPRT0_SPD_MASK) >> HPRT0_SPD_SHIFT;
139 		if (prtspd == HPRT0_SPD_HIGH_SPEED &&
140 		    (dev_speed == USB_SPEED_LOW ||
141 		     dev_speed == USB_SPEED_FULL)) {
142 			qh->interval *= 8;
143 			qh->sched_frame |= 0x7;
144 			qh->start_split_frame = qh->sched_frame;
145 		}
146 		dev_dbg(hsotg->dev, "interval=%d\n", qh->interval);
147 	}
148 
149 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH Initialized\n");
150 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - qh = %p\n", qh);
151 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Device Address = %d\n",
152 		 dwc2_hcd_get_dev_addr(&urb->pipe_info));
153 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Endpoint %d, %s\n",
154 		 dwc2_hcd_get_ep_num(&urb->pipe_info),
155 		 dwc2_hcd_is_pipe_in(&urb->pipe_info) ? "IN" : "OUT");
156 
157 	qh->dev_speed = dev_speed;
158 
159 #ifdef DWC2_DEBUG
160 	const char *speed, *type;
161 	switch (dev_speed) {
162 	case USB_SPEED_LOW:
163 		speed = "low";
164 		break;
165 	case USB_SPEED_FULL:
166 		speed = "full";
167 		break;
168 	case USB_SPEED_HIGH:
169 		speed = "high";
170 		break;
171 	default:
172 		speed = "?";
173 		break;
174 	}
175 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Speed = %s\n", speed);
176 
177 	switch (qh->ep_type) {
178 	case USB_ENDPOINT_XFER_ISOC:
179 		type = "isochronous";
180 		break;
181 	case USB_ENDPOINT_XFER_INT:
182 		type = "interrupt";
183 		break;
184 	case USB_ENDPOINT_XFER_CONTROL:
185 		type = "control";
186 		break;
187 	case USB_ENDPOINT_XFER_BULK:
188 		type = "bulk";
189 		break;
190 	default:
191 		type = "?";
192 		break;
193 	}
194 
195 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Type = %s\n", type);
196 #endif
197 
198 	if (qh->ep_type == USB_ENDPOINT_XFER_INT) {
199 		dev_vdbg(hsotg->dev, "DWC OTG HCD QH - usecs = %d\n",
200 			 qh->usecs);
201 		dev_vdbg(hsotg->dev, "DWC OTG HCD QH - interval = %d\n",
202 			 qh->interval);
203 	}
204 }
205 
206 /**
207  * dwc2_hcd_qh_create() - Allocates and initializes a QH
208  *
209  * @hsotg:     The HCD state structure for the DWC OTG controller
210  * @urb:       Holds the information about the device/endpoint needed
211  *             to initialize the QH
212  * @mem_flags: Flag to do atomic allocation if needed
213  *
214  * Return: Pointer to the newly allocated QH, or NULL on error
215  */
216 struct dwc2_qh *dwc2_hcd_qh_create(struct dwc2_hsotg *hsotg,
217 					  struct dwc2_hcd_urb *urb,
218 					  gfp_t mem_flags)
219 {
220 	struct dwc2_softc *sc = hsotg->hsotg_sc;
221 	struct dwc2_qh *qh;
222 
223 	if (!urb->priv)
224 		return NULL;
225 
226 	/* Allocate memory */
227 	qh = pool_get(&sc->sc_qhpool, PR_NOWAIT);
228 	if (!qh)
229 		return NULL;
230 
231 	memset(qh, 0, sizeof(*qh));
232 	dwc2_qh_init(hsotg, qh, urb);
233 
234 	if (hsotg->core_params->dma_desc_enable > 0 &&
235 	    dwc2_hcd_qh_init_ddma(hsotg, qh, mem_flags) < 0) {
236 		dwc2_hcd_qh_free(hsotg, qh);
237 		return NULL;
238 	}
239 
240 	return qh;
241 }
242 
243 /**
244  * dwc2_hcd_qh_free() - Frees the QH
245  *
246  * @hsotg: HCD instance
247  * @qh:    The QH to free
248  *
249  * QH should already be removed from the list. QTD list should already be empty
250  * if called from URB Dequeue.
251  *
252  * Must NOT be called with interrupt disabled or spinlock held
253  */
254 void dwc2_hcd_qh_free(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
255 {
256 	struct dwc2_softc *sc = hsotg->hsotg_sc;
257 
258 	/*
259 	 * We don't have the lock so we can safely wait until the wait timer
260 	 * finishes.  Of course, at this point in time we'd better have set
261 	 * wait_timer_active to false so if this timer was still pending it
262 	 * won't do anything anyway, but we want it to finish before we free
263 	 * memory.
264 	 */
265 	/* XXX del_timer_sync(&qh->wait_timer); */
266 
267 	timeout_del(&qh->wait_timer);
268 	if (qh->desc_list) {
269 		dwc2_hcd_qh_free_ddma(hsotg, qh);
270 	} else if (qh->dw_align_buf) {
271 		usb_freemem(&sc->sc_bus, &qh->dw_align_buf_usbdma);
272  		qh->dw_align_buf_dma = (dma_addr_t)0;
273 	}
274 
275 	pool_put(&sc->sc_qhpool, qh);
276 }
277 
278 /**
279  * dwc2_periodic_channel_available() - Checks that a channel is available for a
280  * periodic transfer
281  *
282  * @hsotg: The HCD state structure for the DWC OTG controller
283  *
284  * Return: 0 if successful, negative error code otherwise
285  */
286 STATIC int dwc2_periodic_channel_available(struct dwc2_hsotg *hsotg)
287 {
288 	/*
289 	 * Currently assuming that there is a dedicated host channel for
290 	 * each periodic transaction plus at least one host channel for
291 	 * non-periodic transactions
292 	 */
293 	int status;
294 	int num_channels;
295 
296 	num_channels = hsotg->core_params->host_channels;
297 	if (hsotg->periodic_channels + hsotg->non_periodic_channels <
298 								num_channels
299 	    && hsotg->periodic_channels < num_channels - 1) {
300 		status = 0;
301 	} else {
302 		dev_dbg(hsotg->dev,
303 			"%s: Total channels: %d, Periodic: %d, "
304 			"Non-periodic: %d\n", __func__, num_channels,
305 			hsotg->periodic_channels, hsotg->non_periodic_channels);
306 		status = -ENOSPC;
307 	}
308 
309 	return status;
310 }
311 
312 /**
313  * dwc2_check_periodic_bandwidth() - Checks that there is sufficient bandwidth
314  * for the specified QH in the periodic schedule
315  *
316  * @hsotg: The HCD state structure for the DWC OTG controller
317  * @qh:    QH containing periodic bandwidth required
318  *
319  * Return: 0 if successful, negative error code otherwise
320  *
321  * For simplicity, this calculation assumes that all the transfers in the
322  * periodic schedule may occur in the same (micro)frame
323  */
324 STATIC int dwc2_check_periodic_bandwidth(struct dwc2_hsotg *hsotg,
325 					 struct dwc2_qh *qh)
326 {
327 	int status;
328 	s16 max_claimed_usecs;
329 
330 	status = 0;
331 
332 	if (qh->dev_speed == USB_SPEED_HIGH || qh->do_split) {
333 		/*
334 		 * High speed mode
335 		 * Max periodic usecs is 80% x 125 usec = 100 usec
336 		 */
337 		max_claimed_usecs = 100 - qh->usecs;
338 	} else {
339 		/*
340 		 * Full speed mode
341 		 * Max periodic usecs is 90% x 1000 usec = 900 usec
342 		 */
343 		max_claimed_usecs = 900 - qh->usecs;
344 	}
345 
346 	if (hsotg->periodic_usecs > max_claimed_usecs) {
347 		dev_err(hsotg->dev,
348 			"%s: already claimed usecs %d, required usecs %d\n",
349 			__func__, hsotg->periodic_usecs, qh->usecs);
350 		status = -ENOSPC;
351 	}
352 
353 	return status;
354 }
355 
356 /**
357  * Microframe scheduler
358  * track the total use in hsotg->frame_usecs
359  * keep each qh use in qh->frame_usecs
360  * when surrendering the qh then donate the time back
361  */
362 STATIC const unsigned short max_uframe_usecs[] = {
363 	100, 100, 100, 100, 100, 100, 30, 0
364 };
365 
366 void dwc2_hcd_init_usecs(struct dwc2_hsotg *hsotg)
367 {
368 	int i;
369 
370 	for (i = 0; i < 8; i++)
371 		hsotg->frame_usecs[i] = max_uframe_usecs[i];
372 }
373 
374 STATIC int dwc2_find_single_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
375 {
376 	unsigned short utime = qh->usecs;
377 	int i;
378 
379 	for (i = 0; i < 8; i++) {
380 		/* At the start hsotg->frame_usecs[i] = max_uframe_usecs[i] */
381 		if (utime <= hsotg->frame_usecs[i]) {
382 			hsotg->frame_usecs[i] -= utime;
383 			qh->frame_usecs[i] += utime;
384 			return i;
385 		}
386 	}
387 	return -ENOSPC;
388 }
389 
390 /*
391  * use this for FS apps that can span multiple uframes
392  */
393 STATIC int dwc2_find_multi_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
394 {
395 	unsigned short utime = qh->usecs;
396 	unsigned short xtime;
397 	int t_left;
398 	int i;
399 	int j;
400 	int k;
401 
402 	for (i = 0; i < 8; i++) {
403 		if (hsotg->frame_usecs[i] <= 0)
404 			continue;
405 
406 		/*
407 		 * we need n consecutive slots so use j as a start slot
408 		 * j plus j+1 must be enough time (for now)
409 		 */
410 		xtime = hsotg->frame_usecs[i];
411 		for (j = i + 1; j < 8; j++) {
412 			/*
413 			 * if we add this frame remaining time to xtime we may
414 			 * be OK, if not we need to test j for a complete frame
415 			 */
416 			if (xtime + hsotg->frame_usecs[j] < utime) {
417 				if (hsotg->frame_usecs[j] <
418 							max_uframe_usecs[j])
419 					continue;
420 			}
421 			if (xtime >= utime) {
422 				t_left = utime;
423 				for (k = i; k < 8; k++) {
424 					t_left -= hsotg->frame_usecs[k];
425 					if (t_left <= 0) {
426 						qh->frame_usecs[k] +=
427 							hsotg->frame_usecs[k]
428 								+ t_left;
429 						hsotg->frame_usecs[k] = -t_left;
430 						return i;
431 					} else {
432 						qh->frame_usecs[k] +=
433 							hsotg->frame_usecs[k];
434 						hsotg->frame_usecs[k] = 0;
435 					}
436 				}
437 			}
438 			/* add the frame time to x time */
439 			xtime += hsotg->frame_usecs[j];
440 			/* we must have a fully available next frame or break */
441 			if (xtime < utime &&
442 			   hsotg->frame_usecs[j] == max_uframe_usecs[j])
443 				continue;
444 		}
445 	}
446 	return -ENOSPC;
447 }
448 
449 STATIC int dwc2_find_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
450 {
451 	int ret;
452 
453 	if (qh->dev_speed == USB_SPEED_HIGH) {
454 		/* if this is a hs transaction we need a full frame */
455 		ret = dwc2_find_single_uframe(hsotg, qh);
456 	} else {
457 		/*
458 		 * if this is a fs transaction we may need a sequence
459 		 * of frames
460 		 */
461 		ret = dwc2_find_multi_uframe(hsotg, qh);
462 	}
463 	return ret;
464 }
465 
466 /**
467  * dwc2_check_max_xfer_size() - Checks that the max transfer size allowed in a
468  * host channel is large enough to handle the maximum data transfer in a single
469  * (micro)frame for a periodic transfer
470  *
471  * @hsotg: The HCD state structure for the DWC OTG controller
472  * @qh:    QH for a periodic endpoint
473  *
474  * Return: 0 if successful, negative error code otherwise
475  */
476 STATIC int dwc2_check_max_xfer_size(struct dwc2_hsotg *hsotg,
477 				    struct dwc2_qh *qh)
478 {
479 	u32 max_xfer_size;
480 	u32 max_channel_xfer_size;
481 	int status = 0;
482 
483 	max_xfer_size = dwc2_max_packet(qh->maxp) * dwc2_hb_mult(qh->maxp);
484 	max_channel_xfer_size = hsotg->core_params->max_transfer_size;
485 
486 	if (max_xfer_size > max_channel_xfer_size) {
487 		dev_err(hsotg->dev,
488 			"%s: Periodic xfer length %d > max xfer length for channel %d\n",
489 			__func__, max_xfer_size, max_channel_xfer_size);
490 		status = -ENOSPC;
491 	}
492 
493 	return status;
494 }
495 
496 /**
497  * dwc2_schedule_periodic() - Schedules an interrupt or isochronous transfer in
498  * the periodic schedule
499  *
500  * @hsotg: The HCD state structure for the DWC OTG controller
501  * @qh:    QH for the periodic transfer. The QH should already contain the
502  *         scheduling information.
503  *
504  * Return: 0 if successful, negative error code otherwise
505  */
506 STATIC int dwc2_schedule_periodic(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
507 {
508 	int status;
509 
510 	if (hsotg->core_params->uframe_sched > 0) {
511 		int frame = -1;
512 
513 		status = dwc2_find_uframe(hsotg, qh);
514 		if (status == 0)
515 			frame = 7;
516 		else if (status > 0)
517 			frame = status - 1;
518 
519 		/* Set the new frame up */
520 		if (frame >= 0) {
521 			qh->sched_frame &= ~0x7;
522 			qh->sched_frame |= (frame & 7);
523 		}
524 
525 		if (status > 0)
526 			status = 0;
527 	} else {
528 		status = dwc2_periodic_channel_available(hsotg);
529 		if (status) {
530 			dev_info(hsotg->dev,
531 				 "%s: No host channel available for periodic transfer\n",
532 				 __func__);
533 			return status;
534 		}
535 
536 		status = dwc2_check_periodic_bandwidth(hsotg, qh);
537 	}
538 
539 	if (status) {
540 		dev_dbg(hsotg->dev,
541 			"%s: Insufficient periodic bandwidth for periodic transfer\n",
542 			__func__);
543 		return status;
544 	}
545 
546 	status = dwc2_check_max_xfer_size(hsotg, qh);
547 	if (status) {
548 		dev_dbg(hsotg->dev,
549 			"%s: Channel max transfer size too small for periodic transfer\n",
550 			__func__);
551 		return status;
552 	}
553 
554 	if (hsotg->core_params->dma_desc_enable > 0)
555 		/* Don't rely on SOF and start in ready schedule */
556 		list_add_tail(&qh->qh_list_entry, &hsotg->periodic_sched_ready);
557 	else
558 		/* Always start in inactive schedule */
559 		list_add_tail(&qh->qh_list_entry,
560 			      &hsotg->periodic_sched_inactive);
561 
562 	if (hsotg->core_params->uframe_sched <= 0)
563 		/* Reserve periodic channel */
564 		hsotg->periodic_channels++;
565 
566 	/* Update claimed usecs per (micro)frame */
567 	hsotg->periodic_usecs += qh->usecs;
568 
569 	return status;
570 }
571 
572 /**
573  * dwc2_deschedule_periodic() - Removes an interrupt or isochronous transfer
574  * from the periodic schedule
575  *
576  * @hsotg: The HCD state structure for the DWC OTG controller
577  * @qh:	   QH for the periodic transfer
578  */
579 STATIC void dwc2_deschedule_periodic(struct dwc2_hsotg *hsotg,
580 				     struct dwc2_qh *qh)
581 {
582 	int i;
583 
584 	list_del_init(&qh->qh_list_entry);
585 
586 	/* Update claimed usecs per (micro)frame */
587 	hsotg->periodic_usecs -= qh->usecs;
588 
589 	if (hsotg->core_params->uframe_sched > 0) {
590 		for (i = 0; i < 8; i++) {
591 			hsotg->frame_usecs[i] += qh->frame_usecs[i];
592 			qh->frame_usecs[i] = 0;
593 		}
594 	} else {
595 		/* Release periodic channel reservation */
596 		hsotg->periodic_channels--;
597 	}
598 }
599 
600 /**
601  * dwc2_wait_timer_fn() - Timer function to re-queue after waiting
602  *
603  * As per the spec, a NAK indicates that "a function is temporarily unable to
604  * transmit or receive data, but will eventually be able to do so without need
605  * of host intervention".
606  *
607  * That means that when we encounter a NAK we're supposed to retry.
608  *
609  * ...but if we retry right away (from the interrupt handler that saw the NAK)
610  * then we can end up with an interrupt storm (if the other side keeps NAKing
611  * us) because on slow enough CPUs it could take us longer to get out of the
612  * interrupt routine than it takes for the device to send another NAK.  That
613  * leads to a constant stream of NAK interrupts and the CPU locks.
614  *
615  * ...so instead of retrying right away in the case of a NAK we'll set a timer
616  * to retry some time later.  This function handles that timer and moves the
617  * qh back to the "inactive" list, then queues transactions.
618  *
619  * @t: Pointer to wait_timer in a qh.
620  */
621 STATIC void dwc2_wait_timer_fn(void *arg)
622 {
623 	struct dwc2_qh *qh = arg;
624 	struct dwc2_hsotg *hsotg = qh->hsotg;
625 	unsigned long flags;
626 
627 	spin_lock_irqsave(&hsotg->lock, flags);
628 
629 	/*
630 	 * We'll set wait_timer_cancel to true if we want to cancel this
631 	 * operation in dwc2_hcd_qh_unlink().
632 	 */
633 	if (!qh->wait_timer_cancel) {
634 		enum dwc2_transaction_type tr_type;
635 
636 		qh->want_wait = false;
637 
638 		list_move(&qh->qh_list_entry,
639 			  &hsotg->non_periodic_sched_inactive);
640 
641 		tr_type = dwc2_hcd_select_transactions(hsotg);
642 		if (tr_type != DWC2_TRANSACTION_NONE)
643 			dwc2_hcd_queue_transactions(hsotg, tr_type);
644 	}
645 
646 	spin_unlock_irqrestore(&hsotg->lock, flags);
647 }
648 
649 /**
650  * dwc2_hcd_qh_add() - Adds a QH to either the non periodic or periodic
651  * schedule if it is not already in the schedule. If the QH is already in
652  * the schedule, no action is taken.
653  *
654  * @hsotg: The HCD state structure for the DWC OTG controller
655  * @qh:    The QH to add
656  *
657  * Return: 0 if successful, negative error code otherwise
658  */
659 int dwc2_hcd_qh_add(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
660 {
661 	int status;
662 	u32 intr_mask;
663 
664 	if (dbg_qh(qh))
665 		dev_vdbg(hsotg->dev, "%s()\n", __func__);
666 
667 	if (!list_empty(&qh->qh_list_entry))
668 		/* QH already in a schedule */
669 		return 0;
670 
671 	if (!dwc2_frame_num_le(qh->sched_frame, hsotg->frame_number) &&
672 			!hsotg->frame_number) {
673 		dev_dbg(hsotg->dev,
674 				"reset frame number counter\n");
675 		qh->sched_frame = dwc2_frame_num_inc(hsotg->frame_number,
676 				SCHEDULE_SLOP);
677 	}
678 
679 	/* Add the new QH to the appropriate schedule */
680 	if (dwc2_qh_is_non_per(qh)) {
681 		if (qh->want_wait) {
682 			list_add_tail(&qh->qh_list_entry,
683 				      &hsotg->non_periodic_sched_waiting);
684 			qh->wait_timer_cancel = false;
685 			/* XXX mod_timer(&qh->wait_timer,
686 				  jiffies + DWC2_RETRY_WAIT_DELAY + 1); */
687 			timeout_add_msec(&qh->wait_timer,
688 			    DWC2_RETRY_WAIT_DELAY);
689 		} else {
690 			list_add_tail(&qh->qh_list_entry,
691 				      &hsotg->non_periodic_sched_inactive);
692 		}
693 		return 0;
694 	}
695 
696 	status = dwc2_schedule_periodic(hsotg, qh);
697 	if (status)
698 		return status;
699 	if (!hsotg->periodic_qh_count) {
700 		intr_mask = DWC2_READ_4(hsotg, GINTMSK);
701 		intr_mask |= GINTSTS_SOF;
702 		DWC2_WRITE_4(hsotg, GINTMSK, intr_mask);
703 	}
704 	hsotg->periodic_qh_count++;
705 
706 	return 0;
707 }
708 
709 /**
710  * dwc2_hcd_qh_unlink() - Removes a QH from either the non-periodic or periodic
711  * schedule. Memory is not freed.
712  *
713  * @hsotg: The HCD state structure
714  * @qh:    QH to remove from schedule
715  */
716 void dwc2_hcd_qh_unlink(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
717 {
718 	u32 intr_mask;
719 
720 	dev_vdbg(hsotg->dev, "%s()\n", __func__);
721 
722 	/* If the wait_timer is pending, this will stop it from acting */
723 	qh->wait_timer_cancel = true;
724 
725 	if (list_empty(&qh->qh_list_entry))
726 		/* QH is not in a schedule */
727 		return;
728 
729 	if (dwc2_qh_is_non_per(qh)) {
730 		if (hsotg->non_periodic_qh_ptr == &qh->qh_list_entry)
731 			hsotg->non_periodic_qh_ptr =
732 					hsotg->non_periodic_qh_ptr->next;
733 		list_del_init(&qh->qh_list_entry);
734 		return;
735 	}
736 
737 	dwc2_deschedule_periodic(hsotg, qh);
738 	hsotg->periodic_qh_count--;
739 	if (!hsotg->periodic_qh_count) {
740 		intr_mask = DWC2_READ_4(hsotg, GINTMSK);
741 		intr_mask &= ~GINTSTS_SOF;
742 		DWC2_WRITE_4(hsotg, GINTMSK, intr_mask);
743 	}
744 }
745 
746 /*
747  * Schedule the next continuing periodic split transfer
748  */
749 STATIC void dwc2_sched_periodic_split(struct dwc2_hsotg *hsotg,
750 				      struct dwc2_qh *qh, u16 frame_number,
751 				      int sched_next_periodic_split)
752 {
753 	u16 incr;
754 
755 	if (sched_next_periodic_split) {
756 		qh->sched_frame = frame_number;
757 		incr = dwc2_frame_num_inc(qh->start_split_frame, 1);
758 		if (dwc2_frame_num_le(frame_number, incr)) {
759 			/*
760 			 * Allow one frame to elapse after start split
761 			 * microframe before scheduling complete split, but
762 			 * DON'T if we are doing the next start split in the
763 			 * same frame for an ISOC out
764 			 */
765 			if (qh->ep_type != USB_ENDPOINT_XFER_ISOC ||
766 			    qh->ep_is_in != 0) {
767 				qh->sched_frame =
768 					dwc2_frame_num_inc(qh->sched_frame, 1);
769 			}
770 		}
771 	} else {
772 		qh->sched_frame = dwc2_frame_num_inc(qh->start_split_frame,
773 						     qh->interval);
774 		if (dwc2_frame_num_le(qh->sched_frame, frame_number))
775 			qh->sched_frame = frame_number;
776 		qh->sched_frame |= 0x7;
777 		qh->start_split_frame = qh->sched_frame;
778 	}
779 }
780 
781 /*
782  * Deactivates a QH. For non-periodic QHs, removes the QH from the active
783  * non-periodic schedule. The QH is added to the inactive non-periodic
784  * schedule if any QTDs are still attached to the QH.
785  *
786  * For periodic QHs, the QH is removed from the periodic queued schedule. If
787  * there are any QTDs still attached to the QH, the QH is added to either the
788  * periodic inactive schedule or the periodic ready schedule and its next
789  * scheduled frame is calculated. The QH is placed in the ready schedule if
790  * the scheduled frame has been reached already. Otherwise it's placed in the
791  * inactive schedule. If there are no QTDs attached to the QH, the QH is
792  * completely removed from the periodic schedule.
793  */
794 void dwc2_hcd_qh_deactivate(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
795 			    int sched_next_periodic_split)
796 {
797 	u16 frame_number;
798 
799 	if (dbg_qh(qh))
800 		dev_vdbg(hsotg->dev, "%s()\n", __func__);
801 
802 	if (dwc2_qh_is_non_per(qh)) {
803 		dwc2_hcd_qh_unlink(hsotg, qh);
804 		if (!list_empty(&qh->qtd_list))
805 			/* Add back to inactive/waiting non-periodic schedule */
806 			dwc2_hcd_qh_add(hsotg, qh);
807 		return;
808 	}
809 
810 	frame_number = dwc2_hcd_get_frame_number(hsotg);
811 
812 	if (qh->do_split) {
813 		dwc2_sched_periodic_split(hsotg, qh, frame_number,
814 					  sched_next_periodic_split);
815 	} else {
816 		qh->sched_frame = dwc2_frame_num_inc(qh->sched_frame,
817 						     qh->interval);
818 		if (dwc2_frame_num_le(qh->sched_frame, frame_number))
819 			qh->sched_frame = frame_number;
820 	}
821 
822 	if (list_empty(&qh->qtd_list)) {
823 		dwc2_hcd_qh_unlink(hsotg, qh);
824 		return;
825 	}
826 	/*
827 	 * Remove from periodic_sched_queued and move to
828 	 * appropriate queue
829 	 */
830 	if ((hsotg->core_params->uframe_sched > 0 &&
831 	     dwc2_frame_num_le(qh->sched_frame, frame_number)) ||
832 	    (hsotg->core_params->uframe_sched <= 0 &&
833 	     qh->sched_frame == frame_number))
834 		list_move(&qh->qh_list_entry, &hsotg->periodic_sched_ready);
835 	else
836 		list_move(&qh->qh_list_entry, &hsotg->periodic_sched_inactive);
837 }
838 
839 /**
840  * dwc2_hcd_qtd_init() - Initializes a QTD structure
841  *
842  * @qtd: The QTD to initialize
843  * @urb: The associated URB
844  */
845 void dwc2_hcd_qtd_init(struct dwc2_qtd *qtd, struct dwc2_hcd_urb *urb)
846 {
847 	qtd->urb = urb;
848 	if (dwc2_hcd_get_pipe_type(&urb->pipe_info) ==
849 			USB_ENDPOINT_XFER_CONTROL) {
850 		/*
851 		 * The only time the QTD data toggle is used is on the data
852 		 * phase of control transfers. This phase always starts with
853 		 * DATA1.
854 		 */
855 		qtd->data_toggle = DWC2_HC_PID_DATA1;
856 		qtd->control_phase = DWC2_CONTROL_SETUP;
857 	}
858 
859 	/* Start split */
860 	qtd->complete_split = 0;
861 	qtd->isoc_split_pos = DWC2_HCSPLT_XACTPOS_ALL;
862 	qtd->isoc_split_offset = 0;
863 	qtd->in_process = 0;
864 
865 	/* Store the qtd ptr in the urb to reference the QTD */
866 	urb->qtd = qtd;
867 }
868 
869 /**
870  * dwc2_hcd_qtd_add() - Adds a QTD to the QTD-list of a QH
871  *			Caller must hold driver lock.
872  *
873  * @hsotg:        The DWC HCD structure
874  * @qtd:          The QTD to add
875  * @qh:           Queue head to add qtd to
876  *
877  * Return: 0 if successful, negative error code otherwise
878  *
879  * If the QH to which the QTD is added is not currently scheduled, it is placed
880  * into the proper schedule based on its EP type.
881  */
882 int dwc2_hcd_qtd_add(struct dwc2_hsotg *hsotg, struct dwc2_qtd *qtd,
883 		     struct dwc2_qh *qh)
884 {
885 
886 	MUTEX_ASSERT_LOCKED(&hsotg->lock);
887 	int retval;
888 
889 	if (!qh) {
890 		dev_err(hsotg->dev, "%s: Invalid QH\n", __func__);
891 		retval = -EINVAL;
892 		goto fail;
893 	}
894 
895 	retval = dwc2_hcd_qh_add(hsotg, qh);
896 	if (retval)
897 		goto fail;
898 
899 	qtd->qh = qh;
900 	list_add_tail(&qtd->qtd_list_entry, &qh->qtd_list);
901 
902 	return 0;
903 fail:
904 	return retval;
905 }
906 
907 void dwc2_hcd_qtd_unlink_and_free(struct dwc2_hsotg *hsotg,
908 				  struct dwc2_qtd *qtd,
909 				  struct dwc2_qh *qh)
910 {
911 	struct dwc2_softc *sc = hsotg->hsotg_sc;
912 
913 	list_del_init(&qtd->qtd_list_entry);
914  	pool_put(&sc->sc_qtdpool, qtd);
915 }
916 
917 #define BITSTUFFTIME(bytecount)	((8 * 7 * (bytecount)) / 6)
918 #define HS_HOST_DELAY		5	/* nanoseconds */
919 #define FS_LS_HOST_DELAY	1000	/* nanoseconds */
920 #define HUB_LS_SETUP		333	/* nanoseconds */
921 
922 STATIC u32 dwc2_calc_bus_time(struct dwc2_hsotg *hsotg, int speed, int is_in,
923 			      int is_isoc, int bytecount)
924 {
925 	unsigned long retval;
926 
927 	switch (speed) {
928 	case USB_SPEED_HIGH:
929 		if (is_isoc)
930 			retval =
931 			    ((38 * 8 * 2083) +
932 			     (2083 * (3 + BITSTUFFTIME(bytecount)))) / 1000 +
933 			    HS_HOST_DELAY;
934 		else
935 			retval =
936 			    ((55 * 8 * 2083) +
937 			     (2083 * (3 + BITSTUFFTIME(bytecount)))) / 1000 +
938 			    HS_HOST_DELAY;
939 		break;
940 	case USB_SPEED_FULL:
941 		if (is_isoc) {
942 			retval =
943 			    (8354 * (31 + 10 * BITSTUFFTIME(bytecount))) / 1000;
944 			if (is_in)
945 				retval = 7268 + FS_LS_HOST_DELAY + retval;
946 			else
947 				retval = 6265 + FS_LS_HOST_DELAY + retval;
948 		} else {
949 			retval =
950 			    (8354 * (31 + 10 * BITSTUFFTIME(bytecount))) / 1000;
951 			retval = 9107 + FS_LS_HOST_DELAY + retval;
952 		}
953 		break;
954 	case USB_SPEED_LOW:
955 		if (is_in) {
956 			retval =
957 			    (67667 * (31 + 10 * BITSTUFFTIME(bytecount))) /
958 			    1000;
959 			retval =
960 			    64060 + (2 * HUB_LS_SETUP) + FS_LS_HOST_DELAY +
961 			    retval;
962 		} else {
963 			retval =
964 			    (66700 * (31 + 10 * BITSTUFFTIME(bytecount))) /
965 			    1000;
966 			retval =
967 			    64107 + (2 * HUB_LS_SETUP) + FS_LS_HOST_DELAY +
968 			    retval;
969 		}
970 		break;
971 	default:
972 		dev_warn(hsotg->dev, "Unknown device speed\n");
973 		retval = -1;
974 	}
975 
976 	return NS_TO_US(retval);
977 }
978