xref: /openbmc/linux/drivers/usb/dwc2/hcd_queue.c (revision 9cfc5c90)
1 /*
2  * hcd_queue.c - DesignWare HS OTG Controller host queuing routines
3  *
4  * Copyright (C) 2004-2013 Synopsys, Inc.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions, and the following disclaimer,
11  *    without modification.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The names of the above-listed copyright holders may not be used
16  *    to endorse or promote products derived from this software without
17  *    specific prior written permission.
18  *
19  * ALTERNATIVELY, this software may be distributed under the terms of the
20  * GNU General Public License ("GPL") as published by the Free Software
21  * Foundation; either version 2 of the License, or (at your option) any
22  * later version.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
25  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
26  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
27  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
28  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
29  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
31  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 /*
38  * This file contains the functions to manage Queue Heads and Queue
39  * Transfer Descriptors for Host mode
40  */
41 #include <linux/kernel.h>
42 #include <linux/module.h>
43 #include <linux/spinlock.h>
44 #include <linux/interrupt.h>
45 #include <linux/dma-mapping.h>
46 #include <linux/io.h>
47 #include <linux/slab.h>
48 #include <linux/usb.h>
49 
50 #include <linux/usb/hcd.h>
51 #include <linux/usb/ch11.h>
52 
53 #include "core.h"
54 #include "hcd.h"
55 
56 /**
57  * dwc2_qh_init() - Initializes a QH structure
58  *
59  * @hsotg: The HCD state structure for the DWC OTG controller
60  * @qh:    The QH to init
61  * @urb:   Holds the information about the device/endpoint needed to initialize
62  *         the QH
63  */
64 #define SCHEDULE_SLOP 10
65 static void dwc2_qh_init(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
66 			 struct dwc2_hcd_urb *urb)
67 {
68 	int dev_speed, hub_addr, hub_port;
69 	char *speed, *type;
70 
71 	dev_vdbg(hsotg->dev, "%s()\n", __func__);
72 
73 	/* Initialize QH */
74 	qh->ep_type = dwc2_hcd_get_pipe_type(&urb->pipe_info);
75 	qh->ep_is_in = dwc2_hcd_is_pipe_in(&urb->pipe_info) ? 1 : 0;
76 
77 	qh->data_toggle = DWC2_HC_PID_DATA0;
78 	qh->maxp = dwc2_hcd_get_mps(&urb->pipe_info);
79 	INIT_LIST_HEAD(&qh->qtd_list);
80 	INIT_LIST_HEAD(&qh->qh_list_entry);
81 
82 	/* FS/LS Endpoint on HS Hub, NOT virtual root hub */
83 	dev_speed = dwc2_host_get_speed(hsotg, urb->priv);
84 
85 	dwc2_host_hub_info(hsotg, urb->priv, &hub_addr, &hub_port);
86 
87 	if ((dev_speed == USB_SPEED_LOW || dev_speed == USB_SPEED_FULL) &&
88 	    hub_addr != 0 && hub_addr != 1) {
89 		dev_vdbg(hsotg->dev,
90 			 "QH init: EP %d: TT found at hub addr %d, for port %d\n",
91 			 dwc2_hcd_get_ep_num(&urb->pipe_info), hub_addr,
92 			 hub_port);
93 		qh->do_split = 1;
94 	}
95 
96 	if (qh->ep_type == USB_ENDPOINT_XFER_INT ||
97 	    qh->ep_type == USB_ENDPOINT_XFER_ISOC) {
98 		/* Compute scheduling parameters once and save them */
99 		u32 hprt, prtspd;
100 
101 		/* Todo: Account for split transfers in the bus time */
102 		int bytecount =
103 			dwc2_hb_mult(qh->maxp) * dwc2_max_packet(qh->maxp);
104 
105 		qh->usecs = NS_TO_US(usb_calc_bus_time(qh->do_split ?
106 				USB_SPEED_HIGH : dev_speed, qh->ep_is_in,
107 				qh->ep_type == USB_ENDPOINT_XFER_ISOC,
108 				bytecount));
109 
110 		/* Ensure frame_number corresponds to the reality */
111 		hsotg->frame_number = dwc2_hcd_get_frame_number(hsotg);
112 		/* Start in a slightly future (micro)frame */
113 		qh->sched_frame = dwc2_frame_num_inc(hsotg->frame_number,
114 						     SCHEDULE_SLOP);
115 		qh->interval = urb->interval;
116 #if 0
117 		/* Increase interrupt polling rate for debugging */
118 		if (qh->ep_type == USB_ENDPOINT_XFER_INT)
119 			qh->interval = 8;
120 #endif
121 		hprt = dwc2_readl(hsotg->regs + HPRT0);
122 		prtspd = (hprt & HPRT0_SPD_MASK) >> HPRT0_SPD_SHIFT;
123 		if (prtspd == HPRT0_SPD_HIGH_SPEED &&
124 		    (dev_speed == USB_SPEED_LOW ||
125 		     dev_speed == USB_SPEED_FULL)) {
126 			qh->interval *= 8;
127 			qh->sched_frame |= 0x7;
128 			qh->start_split_frame = qh->sched_frame;
129 		}
130 		dev_dbg(hsotg->dev, "interval=%d\n", qh->interval);
131 	}
132 
133 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH Initialized\n");
134 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - qh = %p\n", qh);
135 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Device Address = %d\n",
136 		 dwc2_hcd_get_dev_addr(&urb->pipe_info));
137 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Endpoint %d, %s\n",
138 		 dwc2_hcd_get_ep_num(&urb->pipe_info),
139 		 dwc2_hcd_is_pipe_in(&urb->pipe_info) ? "IN" : "OUT");
140 
141 	qh->dev_speed = dev_speed;
142 
143 	switch (dev_speed) {
144 	case USB_SPEED_LOW:
145 		speed = "low";
146 		break;
147 	case USB_SPEED_FULL:
148 		speed = "full";
149 		break;
150 	case USB_SPEED_HIGH:
151 		speed = "high";
152 		break;
153 	default:
154 		speed = "?";
155 		break;
156 	}
157 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Speed = %s\n", speed);
158 
159 	switch (qh->ep_type) {
160 	case USB_ENDPOINT_XFER_ISOC:
161 		type = "isochronous";
162 		break;
163 	case USB_ENDPOINT_XFER_INT:
164 		type = "interrupt";
165 		break;
166 	case USB_ENDPOINT_XFER_CONTROL:
167 		type = "control";
168 		break;
169 	case USB_ENDPOINT_XFER_BULK:
170 		type = "bulk";
171 		break;
172 	default:
173 		type = "?";
174 		break;
175 	}
176 
177 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Type = %s\n", type);
178 
179 	if (qh->ep_type == USB_ENDPOINT_XFER_INT) {
180 		dev_vdbg(hsotg->dev, "DWC OTG HCD QH - usecs = %d\n",
181 			 qh->usecs);
182 		dev_vdbg(hsotg->dev, "DWC OTG HCD QH - interval = %d\n",
183 			 qh->interval);
184 	}
185 }
186 
187 /**
188  * dwc2_hcd_qh_create() - Allocates and initializes a QH
189  *
190  * @hsotg:        The HCD state structure for the DWC OTG controller
191  * @urb:          Holds the information about the device/endpoint needed
192  *                to initialize the QH
193  * @atomic_alloc: Flag to do atomic allocation if needed
194  *
195  * Return: Pointer to the newly allocated QH, or NULL on error
196  */
197 struct dwc2_qh *dwc2_hcd_qh_create(struct dwc2_hsotg *hsotg,
198 					  struct dwc2_hcd_urb *urb,
199 					  gfp_t mem_flags)
200 {
201 	struct dwc2_qh *qh;
202 
203 	if (!urb->priv)
204 		return NULL;
205 
206 	/* Allocate memory */
207 	qh = kzalloc(sizeof(*qh), mem_flags);
208 	if (!qh)
209 		return NULL;
210 
211 	dwc2_qh_init(hsotg, qh, urb);
212 
213 	if (hsotg->core_params->dma_desc_enable > 0 &&
214 	    dwc2_hcd_qh_init_ddma(hsotg, qh, mem_flags) < 0) {
215 		dwc2_hcd_qh_free(hsotg, qh);
216 		return NULL;
217 	}
218 
219 	return qh;
220 }
221 
222 /**
223  * dwc2_hcd_qh_free() - Frees the QH
224  *
225  * @hsotg: HCD instance
226  * @qh:    The QH to free
227  *
228  * QH should already be removed from the list. QTD list should already be empty
229  * if called from URB Dequeue.
230  *
231  * Must NOT be called with interrupt disabled or spinlock held
232  */
233 void dwc2_hcd_qh_free(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
234 {
235 	if (hsotg->core_params->dma_desc_enable > 0) {
236 		dwc2_hcd_qh_free_ddma(hsotg, qh);
237 	} else {
238 		/* kfree(NULL) is safe */
239 		kfree(qh->dw_align_buf);
240 		qh->dw_align_buf_dma = (dma_addr_t)0;
241 	}
242 	kfree(qh);
243 }
244 
245 /**
246  * dwc2_periodic_channel_available() - Checks that a channel is available for a
247  * periodic transfer
248  *
249  * @hsotg: The HCD state structure for the DWC OTG controller
250  *
251  * Return: 0 if successful, negative error code otherwise
252  */
253 static int dwc2_periodic_channel_available(struct dwc2_hsotg *hsotg)
254 {
255 	/*
256 	 * Currently assuming that there is a dedicated host channel for
257 	 * each periodic transaction plus at least one host channel for
258 	 * non-periodic transactions
259 	 */
260 	int status;
261 	int num_channels;
262 
263 	num_channels = hsotg->core_params->host_channels;
264 	if (hsotg->periodic_channels + hsotg->non_periodic_channels <
265 								num_channels
266 	    && hsotg->periodic_channels < num_channels - 1) {
267 		status = 0;
268 	} else {
269 		dev_dbg(hsotg->dev,
270 			"%s: Total channels: %d, Periodic: %d, "
271 			"Non-periodic: %d\n", __func__, num_channels,
272 			hsotg->periodic_channels, hsotg->non_periodic_channels);
273 		status = -ENOSPC;
274 	}
275 
276 	return status;
277 }
278 
279 /**
280  * dwc2_check_periodic_bandwidth() - Checks that there is sufficient bandwidth
281  * for the specified QH in the periodic schedule
282  *
283  * @hsotg: The HCD state structure for the DWC OTG controller
284  * @qh:    QH containing periodic bandwidth required
285  *
286  * Return: 0 if successful, negative error code otherwise
287  *
288  * For simplicity, this calculation assumes that all the transfers in the
289  * periodic schedule may occur in the same (micro)frame
290  */
291 static int dwc2_check_periodic_bandwidth(struct dwc2_hsotg *hsotg,
292 					 struct dwc2_qh *qh)
293 {
294 	int status;
295 	s16 max_claimed_usecs;
296 
297 	status = 0;
298 
299 	if (qh->dev_speed == USB_SPEED_HIGH || qh->do_split) {
300 		/*
301 		 * High speed mode
302 		 * Max periodic usecs is 80% x 125 usec = 100 usec
303 		 */
304 		max_claimed_usecs = 100 - qh->usecs;
305 	} else {
306 		/*
307 		 * Full speed mode
308 		 * Max periodic usecs is 90% x 1000 usec = 900 usec
309 		 */
310 		max_claimed_usecs = 900 - qh->usecs;
311 	}
312 
313 	if (hsotg->periodic_usecs > max_claimed_usecs) {
314 		dev_err(hsotg->dev,
315 			"%s: already claimed usecs %d, required usecs %d\n",
316 			__func__, hsotg->periodic_usecs, qh->usecs);
317 		status = -ENOSPC;
318 	}
319 
320 	return status;
321 }
322 
323 /**
324  * Microframe scheduler
325  * track the total use in hsotg->frame_usecs
326  * keep each qh use in qh->frame_usecs
327  * when surrendering the qh then donate the time back
328  */
329 static const unsigned short max_uframe_usecs[] = {
330 	100, 100, 100, 100, 100, 100, 30, 0
331 };
332 
333 void dwc2_hcd_init_usecs(struct dwc2_hsotg *hsotg)
334 {
335 	int i;
336 
337 	for (i = 0; i < 8; i++)
338 		hsotg->frame_usecs[i] = max_uframe_usecs[i];
339 }
340 
341 static int dwc2_find_single_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
342 {
343 	unsigned short utime = qh->usecs;
344 	int i;
345 
346 	for (i = 0; i < 8; i++) {
347 		/* At the start hsotg->frame_usecs[i] = max_uframe_usecs[i] */
348 		if (utime <= hsotg->frame_usecs[i]) {
349 			hsotg->frame_usecs[i] -= utime;
350 			qh->frame_usecs[i] += utime;
351 			return i;
352 		}
353 	}
354 	return -ENOSPC;
355 }
356 
357 /*
358  * use this for FS apps that can span multiple uframes
359  */
360 static int dwc2_find_multi_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
361 {
362 	unsigned short utime = qh->usecs;
363 	unsigned short xtime;
364 	int t_left;
365 	int i;
366 	int j;
367 	int k;
368 
369 	for (i = 0; i < 8; i++) {
370 		if (hsotg->frame_usecs[i] <= 0)
371 			continue;
372 
373 		/*
374 		 * we need n consecutive slots so use j as a start slot
375 		 * j plus j+1 must be enough time (for now)
376 		 */
377 		xtime = hsotg->frame_usecs[i];
378 		for (j = i + 1; j < 8; j++) {
379 			/*
380 			 * if we add this frame remaining time to xtime we may
381 			 * be OK, if not we need to test j for a complete frame
382 			 */
383 			if (xtime + hsotg->frame_usecs[j] < utime) {
384 				if (hsotg->frame_usecs[j] <
385 							max_uframe_usecs[j])
386 					continue;
387 			}
388 			if (xtime >= utime) {
389 				t_left = utime;
390 				for (k = i; k < 8; k++) {
391 					t_left -= hsotg->frame_usecs[k];
392 					if (t_left <= 0) {
393 						qh->frame_usecs[k] +=
394 							hsotg->frame_usecs[k]
395 								+ t_left;
396 						hsotg->frame_usecs[k] = -t_left;
397 						return i;
398 					} else {
399 						qh->frame_usecs[k] +=
400 							hsotg->frame_usecs[k];
401 						hsotg->frame_usecs[k] = 0;
402 					}
403 				}
404 			}
405 			/* add the frame time to x time */
406 			xtime += hsotg->frame_usecs[j];
407 			/* we must have a fully available next frame or break */
408 			if (xtime < utime &&
409 			   hsotg->frame_usecs[j] == max_uframe_usecs[j])
410 				continue;
411 		}
412 	}
413 	return -ENOSPC;
414 }
415 
416 static int dwc2_find_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
417 {
418 	int ret;
419 
420 	if (qh->dev_speed == USB_SPEED_HIGH) {
421 		/* if this is a hs transaction we need a full frame */
422 		ret = dwc2_find_single_uframe(hsotg, qh);
423 	} else {
424 		/*
425 		 * if this is a fs transaction we may need a sequence
426 		 * of frames
427 		 */
428 		ret = dwc2_find_multi_uframe(hsotg, qh);
429 	}
430 	return ret;
431 }
432 
433 /**
434  * dwc2_check_max_xfer_size() - Checks that the max transfer size allowed in a
435  * host channel is large enough to handle the maximum data transfer in a single
436  * (micro)frame for a periodic transfer
437  *
438  * @hsotg: The HCD state structure for the DWC OTG controller
439  * @qh:    QH for a periodic endpoint
440  *
441  * Return: 0 if successful, negative error code otherwise
442  */
443 static int dwc2_check_max_xfer_size(struct dwc2_hsotg *hsotg,
444 				    struct dwc2_qh *qh)
445 {
446 	u32 max_xfer_size;
447 	u32 max_channel_xfer_size;
448 	int status = 0;
449 
450 	max_xfer_size = dwc2_max_packet(qh->maxp) * dwc2_hb_mult(qh->maxp);
451 	max_channel_xfer_size = hsotg->core_params->max_transfer_size;
452 
453 	if (max_xfer_size > max_channel_xfer_size) {
454 		dev_err(hsotg->dev,
455 			"%s: Periodic xfer length %d > max xfer length for channel %d\n",
456 			__func__, max_xfer_size, max_channel_xfer_size);
457 		status = -ENOSPC;
458 	}
459 
460 	return status;
461 }
462 
463 /**
464  * dwc2_schedule_periodic() - Schedules an interrupt or isochronous transfer in
465  * the periodic schedule
466  *
467  * @hsotg: The HCD state structure for the DWC OTG controller
468  * @qh:    QH for the periodic transfer. The QH should already contain the
469  *         scheduling information.
470  *
471  * Return: 0 if successful, negative error code otherwise
472  */
473 static int dwc2_schedule_periodic(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
474 {
475 	int status;
476 
477 	if (hsotg->core_params->uframe_sched > 0) {
478 		int frame = -1;
479 
480 		status = dwc2_find_uframe(hsotg, qh);
481 		if (status == 0)
482 			frame = 7;
483 		else if (status > 0)
484 			frame = status - 1;
485 
486 		/* Set the new frame up */
487 		if (frame >= 0) {
488 			qh->sched_frame &= ~0x7;
489 			qh->sched_frame |= (frame & 7);
490 		}
491 
492 		if (status > 0)
493 			status = 0;
494 	} else {
495 		status = dwc2_periodic_channel_available(hsotg);
496 		if (status) {
497 			dev_info(hsotg->dev,
498 				 "%s: No host channel available for periodic transfer\n",
499 				 __func__);
500 			return status;
501 		}
502 
503 		status = dwc2_check_periodic_bandwidth(hsotg, qh);
504 	}
505 
506 	if (status) {
507 		dev_dbg(hsotg->dev,
508 			"%s: Insufficient periodic bandwidth for periodic transfer\n",
509 			__func__);
510 		return status;
511 	}
512 
513 	status = dwc2_check_max_xfer_size(hsotg, qh);
514 	if (status) {
515 		dev_dbg(hsotg->dev,
516 			"%s: Channel max transfer size too small for periodic transfer\n",
517 			__func__);
518 		return status;
519 	}
520 
521 	if (hsotg->core_params->dma_desc_enable > 0)
522 		/* Don't rely on SOF and start in ready schedule */
523 		list_add_tail(&qh->qh_list_entry, &hsotg->periodic_sched_ready);
524 	else
525 		/* Always start in inactive schedule */
526 		list_add_tail(&qh->qh_list_entry,
527 			      &hsotg->periodic_sched_inactive);
528 
529 	if (hsotg->core_params->uframe_sched <= 0)
530 		/* Reserve periodic channel */
531 		hsotg->periodic_channels++;
532 
533 	/* Update claimed usecs per (micro)frame */
534 	hsotg->periodic_usecs += qh->usecs;
535 
536 	return status;
537 }
538 
539 /**
540  * dwc2_deschedule_periodic() - Removes an interrupt or isochronous transfer
541  * from the periodic schedule
542  *
543  * @hsotg: The HCD state structure for the DWC OTG controller
544  * @qh:	   QH for the periodic transfer
545  */
546 static void dwc2_deschedule_periodic(struct dwc2_hsotg *hsotg,
547 				     struct dwc2_qh *qh)
548 {
549 	int i;
550 
551 	list_del_init(&qh->qh_list_entry);
552 
553 	/* Update claimed usecs per (micro)frame */
554 	hsotg->periodic_usecs -= qh->usecs;
555 
556 	if (hsotg->core_params->uframe_sched > 0) {
557 		for (i = 0; i < 8; i++) {
558 			hsotg->frame_usecs[i] += qh->frame_usecs[i];
559 			qh->frame_usecs[i] = 0;
560 		}
561 	} else {
562 		/* Release periodic channel reservation */
563 		hsotg->periodic_channels--;
564 	}
565 }
566 
567 /**
568  * dwc2_hcd_qh_add() - Adds a QH to either the non periodic or periodic
569  * schedule if it is not already in the schedule. If the QH is already in
570  * the schedule, no action is taken.
571  *
572  * @hsotg: The HCD state structure for the DWC OTG controller
573  * @qh:    The QH to add
574  *
575  * Return: 0 if successful, negative error code otherwise
576  */
577 int dwc2_hcd_qh_add(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
578 {
579 	int status;
580 	u32 intr_mask;
581 
582 	if (dbg_qh(qh))
583 		dev_vdbg(hsotg->dev, "%s()\n", __func__);
584 
585 	if (!list_empty(&qh->qh_list_entry))
586 		/* QH already in a schedule */
587 		return 0;
588 
589 	if (!dwc2_frame_num_le(qh->sched_frame, hsotg->frame_number) &&
590 			!hsotg->frame_number) {
591 		dev_dbg(hsotg->dev,
592 				"reset frame number counter\n");
593 		qh->sched_frame = dwc2_frame_num_inc(hsotg->frame_number,
594 				SCHEDULE_SLOP);
595 	}
596 
597 	/* Add the new QH to the appropriate schedule */
598 	if (dwc2_qh_is_non_per(qh)) {
599 		/* Always start in inactive schedule */
600 		list_add_tail(&qh->qh_list_entry,
601 			      &hsotg->non_periodic_sched_inactive);
602 		return 0;
603 	}
604 
605 	status = dwc2_schedule_periodic(hsotg, qh);
606 	if (status)
607 		return status;
608 	if (!hsotg->periodic_qh_count) {
609 		intr_mask = dwc2_readl(hsotg->regs + GINTMSK);
610 		intr_mask |= GINTSTS_SOF;
611 		dwc2_writel(intr_mask, hsotg->regs + GINTMSK);
612 	}
613 	hsotg->periodic_qh_count++;
614 
615 	return 0;
616 }
617 
618 /**
619  * dwc2_hcd_qh_unlink() - Removes a QH from either the non-periodic or periodic
620  * schedule. Memory is not freed.
621  *
622  * @hsotg: The HCD state structure
623  * @qh:    QH to remove from schedule
624  */
625 void dwc2_hcd_qh_unlink(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
626 {
627 	u32 intr_mask;
628 
629 	dev_vdbg(hsotg->dev, "%s()\n", __func__);
630 
631 	if (list_empty(&qh->qh_list_entry))
632 		/* QH is not in a schedule */
633 		return;
634 
635 	if (dwc2_qh_is_non_per(qh)) {
636 		if (hsotg->non_periodic_qh_ptr == &qh->qh_list_entry)
637 			hsotg->non_periodic_qh_ptr =
638 					hsotg->non_periodic_qh_ptr->next;
639 		list_del_init(&qh->qh_list_entry);
640 		return;
641 	}
642 
643 	dwc2_deschedule_periodic(hsotg, qh);
644 	hsotg->periodic_qh_count--;
645 	if (!hsotg->periodic_qh_count) {
646 		intr_mask = dwc2_readl(hsotg->regs + GINTMSK);
647 		intr_mask &= ~GINTSTS_SOF;
648 		dwc2_writel(intr_mask, hsotg->regs + GINTMSK);
649 	}
650 }
651 
652 /*
653  * Schedule the next continuing periodic split transfer
654  */
655 static void dwc2_sched_periodic_split(struct dwc2_hsotg *hsotg,
656 				      struct dwc2_qh *qh, u16 frame_number,
657 				      int sched_next_periodic_split)
658 {
659 	u16 incr;
660 
661 	if (sched_next_periodic_split) {
662 		qh->sched_frame = frame_number;
663 		incr = dwc2_frame_num_inc(qh->start_split_frame, 1);
664 		if (dwc2_frame_num_le(frame_number, incr)) {
665 			/*
666 			 * Allow one frame to elapse after start split
667 			 * microframe before scheduling complete split, but
668 			 * DON'T if we are doing the next start split in the
669 			 * same frame for an ISOC out
670 			 */
671 			if (qh->ep_type != USB_ENDPOINT_XFER_ISOC ||
672 			    qh->ep_is_in != 0) {
673 				qh->sched_frame =
674 					dwc2_frame_num_inc(qh->sched_frame, 1);
675 			}
676 		}
677 	} else {
678 		qh->sched_frame = dwc2_frame_num_inc(qh->start_split_frame,
679 						     qh->interval);
680 		if (dwc2_frame_num_le(qh->sched_frame, frame_number))
681 			qh->sched_frame = frame_number;
682 		qh->sched_frame |= 0x7;
683 		qh->start_split_frame = qh->sched_frame;
684 	}
685 }
686 
687 /*
688  * Deactivates a QH. For non-periodic QHs, removes the QH from the active
689  * non-periodic schedule. The QH is added to the inactive non-periodic
690  * schedule if any QTDs are still attached to the QH.
691  *
692  * For periodic QHs, the QH is removed from the periodic queued schedule. If
693  * there are any QTDs still attached to the QH, the QH is added to either the
694  * periodic inactive schedule or the periodic ready schedule and its next
695  * scheduled frame is calculated. The QH is placed in the ready schedule if
696  * the scheduled frame has been reached already. Otherwise it's placed in the
697  * inactive schedule. If there are no QTDs attached to the QH, the QH is
698  * completely removed from the periodic schedule.
699  */
700 void dwc2_hcd_qh_deactivate(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
701 			    int sched_next_periodic_split)
702 {
703 	u16 frame_number;
704 
705 	if (dbg_qh(qh))
706 		dev_vdbg(hsotg->dev, "%s()\n", __func__);
707 
708 	if (dwc2_qh_is_non_per(qh)) {
709 		dwc2_hcd_qh_unlink(hsotg, qh);
710 		if (!list_empty(&qh->qtd_list))
711 			/* Add back to inactive non-periodic schedule */
712 			dwc2_hcd_qh_add(hsotg, qh);
713 		return;
714 	}
715 
716 	frame_number = dwc2_hcd_get_frame_number(hsotg);
717 
718 	if (qh->do_split) {
719 		dwc2_sched_periodic_split(hsotg, qh, frame_number,
720 					  sched_next_periodic_split);
721 	} else {
722 		qh->sched_frame = dwc2_frame_num_inc(qh->sched_frame,
723 						     qh->interval);
724 		if (dwc2_frame_num_le(qh->sched_frame, frame_number))
725 			qh->sched_frame = frame_number;
726 	}
727 
728 	if (list_empty(&qh->qtd_list)) {
729 		dwc2_hcd_qh_unlink(hsotg, qh);
730 		return;
731 	}
732 	/*
733 	 * Remove from periodic_sched_queued and move to
734 	 * appropriate queue
735 	 */
736 	if ((hsotg->core_params->uframe_sched > 0 &&
737 	     dwc2_frame_num_le(qh->sched_frame, frame_number)) ||
738 	    (hsotg->core_params->uframe_sched <= 0 &&
739 	     qh->sched_frame == frame_number))
740 		list_move(&qh->qh_list_entry, &hsotg->periodic_sched_ready);
741 	else
742 		list_move(&qh->qh_list_entry, &hsotg->periodic_sched_inactive);
743 }
744 
745 /**
746  * dwc2_hcd_qtd_init() - Initializes a QTD structure
747  *
748  * @qtd: The QTD to initialize
749  * @urb: The associated URB
750  */
751 void dwc2_hcd_qtd_init(struct dwc2_qtd *qtd, struct dwc2_hcd_urb *urb)
752 {
753 	qtd->urb = urb;
754 	if (dwc2_hcd_get_pipe_type(&urb->pipe_info) ==
755 			USB_ENDPOINT_XFER_CONTROL) {
756 		/*
757 		 * The only time the QTD data toggle is used is on the data
758 		 * phase of control transfers. This phase always starts with
759 		 * DATA1.
760 		 */
761 		qtd->data_toggle = DWC2_HC_PID_DATA1;
762 		qtd->control_phase = DWC2_CONTROL_SETUP;
763 	}
764 
765 	/* Start split */
766 	qtd->complete_split = 0;
767 	qtd->isoc_split_pos = DWC2_HCSPLT_XACTPOS_ALL;
768 	qtd->isoc_split_offset = 0;
769 	qtd->in_process = 0;
770 
771 	/* Store the qtd ptr in the urb to reference the QTD */
772 	urb->qtd = qtd;
773 }
774 
775 /**
776  * dwc2_hcd_qtd_add() - Adds a QTD to the QTD-list of a QH
777  *			Caller must hold driver lock.
778  *
779  * @hsotg:        The DWC HCD structure
780  * @qtd:          The QTD to add
781  * @qh:           Queue head to add qtd to
782  *
783  * Return: 0 if successful, negative error code otherwise
784  *
785  * If the QH to which the QTD is added is not currently scheduled, it is placed
786  * into the proper schedule based on its EP type.
787  */
788 int dwc2_hcd_qtd_add(struct dwc2_hsotg *hsotg, struct dwc2_qtd *qtd,
789 		     struct dwc2_qh *qh)
790 {
791 	int retval;
792 
793 	if (unlikely(!qh)) {
794 		dev_err(hsotg->dev, "%s: Invalid QH\n", __func__);
795 		retval = -EINVAL;
796 		goto fail;
797 	}
798 
799 	retval = dwc2_hcd_qh_add(hsotg, qh);
800 	if (retval)
801 		goto fail;
802 
803 	qtd->qh = qh;
804 	list_add_tail(&qtd->qtd_list_entry, &qh->qtd_list);
805 
806 	return 0;
807 fail:
808 	return retval;
809 }
810