xref: /openbmc/linux/drivers/usb/dwc2/hcd_queue.c (revision ca55b2fe)
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 		/* Start in a slightly future (micro)frame */
110 		qh->sched_frame = dwc2_frame_num_inc(hsotg->frame_number,
111 						     SCHEDULE_SLOP);
112 		qh->interval = urb->interval;
113 #if 0
114 		/* Increase interrupt polling rate for debugging */
115 		if (qh->ep_type == USB_ENDPOINT_XFER_INT)
116 			qh->interval = 8;
117 #endif
118 		hprt = readl(hsotg->regs + HPRT0);
119 		prtspd = (hprt & HPRT0_SPD_MASK) >> HPRT0_SPD_SHIFT;
120 		if (prtspd == HPRT0_SPD_HIGH_SPEED &&
121 		    (dev_speed == USB_SPEED_LOW ||
122 		     dev_speed == USB_SPEED_FULL)) {
123 			qh->interval *= 8;
124 			qh->sched_frame |= 0x7;
125 			qh->start_split_frame = qh->sched_frame;
126 		}
127 		dev_dbg(hsotg->dev, "interval=%d\n", qh->interval);
128 	}
129 
130 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH Initialized\n");
131 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - qh = %p\n", qh);
132 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Device Address = %d\n",
133 		 dwc2_hcd_get_dev_addr(&urb->pipe_info));
134 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Endpoint %d, %s\n",
135 		 dwc2_hcd_get_ep_num(&urb->pipe_info),
136 		 dwc2_hcd_is_pipe_in(&urb->pipe_info) ? "IN" : "OUT");
137 
138 	qh->dev_speed = dev_speed;
139 
140 	switch (dev_speed) {
141 	case USB_SPEED_LOW:
142 		speed = "low";
143 		break;
144 	case USB_SPEED_FULL:
145 		speed = "full";
146 		break;
147 	case USB_SPEED_HIGH:
148 		speed = "high";
149 		break;
150 	default:
151 		speed = "?";
152 		break;
153 	}
154 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Speed = %s\n", speed);
155 
156 	switch (qh->ep_type) {
157 	case USB_ENDPOINT_XFER_ISOC:
158 		type = "isochronous";
159 		break;
160 	case USB_ENDPOINT_XFER_INT:
161 		type = "interrupt";
162 		break;
163 	case USB_ENDPOINT_XFER_CONTROL:
164 		type = "control";
165 		break;
166 	case USB_ENDPOINT_XFER_BULK:
167 		type = "bulk";
168 		break;
169 	default:
170 		type = "?";
171 		break;
172 	}
173 
174 	dev_vdbg(hsotg->dev, "DWC OTG HCD QH - Type = %s\n", type);
175 
176 	if (qh->ep_type == USB_ENDPOINT_XFER_INT) {
177 		dev_vdbg(hsotg->dev, "DWC OTG HCD QH - usecs = %d\n",
178 			 qh->usecs);
179 		dev_vdbg(hsotg->dev, "DWC OTG HCD QH - interval = %d\n",
180 			 qh->interval);
181 	}
182 }
183 
184 /**
185  * dwc2_hcd_qh_create() - Allocates and initializes a QH
186  *
187  * @hsotg:        The HCD state structure for the DWC OTG controller
188  * @urb:          Holds the information about the device/endpoint needed
189  *                to initialize the QH
190  * @atomic_alloc: Flag to do atomic allocation if needed
191  *
192  * Return: Pointer to the newly allocated QH, or NULL on error
193  */
194 struct dwc2_qh *dwc2_hcd_qh_create(struct dwc2_hsotg *hsotg,
195 					  struct dwc2_hcd_urb *urb,
196 					  gfp_t mem_flags)
197 {
198 	struct dwc2_qh *qh;
199 
200 	if (!urb->priv)
201 		return NULL;
202 
203 	/* Allocate memory */
204 	qh = kzalloc(sizeof(*qh), mem_flags);
205 	if (!qh)
206 		return NULL;
207 
208 	dwc2_qh_init(hsotg, qh, urb);
209 
210 	if (hsotg->core_params->dma_desc_enable > 0 &&
211 	    dwc2_hcd_qh_init_ddma(hsotg, qh, mem_flags) < 0) {
212 		dwc2_hcd_qh_free(hsotg, qh);
213 		return NULL;
214 	}
215 
216 	return qh;
217 }
218 
219 /**
220  * dwc2_hcd_qh_free() - Frees the QH
221  *
222  * @hsotg: HCD instance
223  * @qh:    The QH to free
224  *
225  * QH should already be removed from the list. QTD list should already be empty
226  * if called from URB Dequeue.
227  *
228  * Must NOT be called with interrupt disabled or spinlock held
229  */
230 void dwc2_hcd_qh_free(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
231 {
232 	if (hsotg->core_params->dma_desc_enable > 0) {
233 		dwc2_hcd_qh_free_ddma(hsotg, qh);
234 	} else {
235 		/* kfree(NULL) is safe */
236 		kfree(qh->dw_align_buf);
237 		qh->dw_align_buf_dma = (dma_addr_t)0;
238 	}
239 	kfree(qh);
240 }
241 
242 /**
243  * dwc2_periodic_channel_available() - Checks that a channel is available for a
244  * periodic transfer
245  *
246  * @hsotg: The HCD state structure for the DWC OTG controller
247  *
248  * Return: 0 if successful, negative error code otherwise
249  */
250 static int dwc2_periodic_channel_available(struct dwc2_hsotg *hsotg)
251 {
252 	/*
253 	 * Currently assuming that there is a dedicated host channel for
254 	 * each periodic transaction plus at least one host channel for
255 	 * non-periodic transactions
256 	 */
257 	int status;
258 	int num_channels;
259 
260 	num_channels = hsotg->core_params->host_channels;
261 	if (hsotg->periodic_channels + hsotg->non_periodic_channels <
262 								num_channels
263 	    && hsotg->periodic_channels < num_channels - 1) {
264 		status = 0;
265 	} else {
266 		dev_dbg(hsotg->dev,
267 			"%s: Total channels: %d, Periodic: %d, "
268 			"Non-periodic: %d\n", __func__, num_channels,
269 			hsotg->periodic_channels, hsotg->non_periodic_channels);
270 		status = -ENOSPC;
271 	}
272 
273 	return status;
274 }
275 
276 /**
277  * dwc2_check_periodic_bandwidth() - Checks that there is sufficient bandwidth
278  * for the specified QH in the periodic schedule
279  *
280  * @hsotg: The HCD state structure for the DWC OTG controller
281  * @qh:    QH containing periodic bandwidth required
282  *
283  * Return: 0 if successful, negative error code otherwise
284  *
285  * For simplicity, this calculation assumes that all the transfers in the
286  * periodic schedule may occur in the same (micro)frame
287  */
288 static int dwc2_check_periodic_bandwidth(struct dwc2_hsotg *hsotg,
289 					 struct dwc2_qh *qh)
290 {
291 	int status;
292 	s16 max_claimed_usecs;
293 
294 	status = 0;
295 
296 	if (qh->dev_speed == USB_SPEED_HIGH || qh->do_split) {
297 		/*
298 		 * High speed mode
299 		 * Max periodic usecs is 80% x 125 usec = 100 usec
300 		 */
301 		max_claimed_usecs = 100 - qh->usecs;
302 	} else {
303 		/*
304 		 * Full speed mode
305 		 * Max periodic usecs is 90% x 1000 usec = 900 usec
306 		 */
307 		max_claimed_usecs = 900 - qh->usecs;
308 	}
309 
310 	if (hsotg->periodic_usecs > max_claimed_usecs) {
311 		dev_err(hsotg->dev,
312 			"%s: already claimed usecs %d, required usecs %d\n",
313 			__func__, hsotg->periodic_usecs, qh->usecs);
314 		status = -ENOSPC;
315 	}
316 
317 	return status;
318 }
319 
320 /**
321  * Microframe scheduler
322  * track the total use in hsotg->frame_usecs
323  * keep each qh use in qh->frame_usecs
324  * when surrendering the qh then donate the time back
325  */
326 static const unsigned short max_uframe_usecs[] = {
327 	100, 100, 100, 100, 100, 100, 30, 0
328 };
329 
330 void dwc2_hcd_init_usecs(struct dwc2_hsotg *hsotg)
331 {
332 	int i;
333 
334 	for (i = 0; i < 8; i++)
335 		hsotg->frame_usecs[i] = max_uframe_usecs[i];
336 }
337 
338 static int dwc2_find_single_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
339 {
340 	unsigned short utime = qh->usecs;
341 	int i;
342 
343 	for (i = 0; i < 8; i++) {
344 		/* At the start hsotg->frame_usecs[i] = max_uframe_usecs[i] */
345 		if (utime <= hsotg->frame_usecs[i]) {
346 			hsotg->frame_usecs[i] -= utime;
347 			qh->frame_usecs[i] += utime;
348 			return i;
349 		}
350 	}
351 	return -ENOSPC;
352 }
353 
354 /*
355  * use this for FS apps that can span multiple uframes
356  */
357 static int dwc2_find_multi_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
358 {
359 	unsigned short utime = qh->usecs;
360 	unsigned short xtime;
361 	int t_left;
362 	int i;
363 	int j;
364 	int k;
365 
366 	for (i = 0; i < 8; i++) {
367 		if (hsotg->frame_usecs[i] <= 0)
368 			continue;
369 
370 		/*
371 		 * we need n consecutive slots so use j as a start slot
372 		 * j plus j+1 must be enough time (for now)
373 		 */
374 		xtime = hsotg->frame_usecs[i];
375 		for (j = i + 1; j < 8; j++) {
376 			/*
377 			 * if we add this frame remaining time to xtime we may
378 			 * be OK, if not we need to test j for a complete frame
379 			 */
380 			if (xtime + hsotg->frame_usecs[j] < utime) {
381 				if (hsotg->frame_usecs[j] <
382 							max_uframe_usecs[j])
383 					continue;
384 			}
385 			if (xtime >= utime) {
386 				t_left = utime;
387 				for (k = i; k < 8; k++) {
388 					t_left -= hsotg->frame_usecs[k];
389 					if (t_left <= 0) {
390 						qh->frame_usecs[k] +=
391 							hsotg->frame_usecs[k]
392 								+ t_left;
393 						hsotg->frame_usecs[k] = -t_left;
394 						return i;
395 					} else {
396 						qh->frame_usecs[k] +=
397 							hsotg->frame_usecs[k];
398 						hsotg->frame_usecs[k] = 0;
399 					}
400 				}
401 			}
402 			/* add the frame time to x time */
403 			xtime += hsotg->frame_usecs[j];
404 			/* we must have a fully available next frame or break */
405 			if (xtime < utime &&
406 			   hsotg->frame_usecs[j] == max_uframe_usecs[j])
407 				continue;
408 		}
409 	}
410 	return -ENOSPC;
411 }
412 
413 static int dwc2_find_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
414 {
415 	int ret;
416 
417 	if (qh->dev_speed == USB_SPEED_HIGH) {
418 		/* if this is a hs transaction we need a full frame */
419 		ret = dwc2_find_single_uframe(hsotg, qh);
420 	} else {
421 		/*
422 		 * if this is a fs transaction we may need a sequence
423 		 * of frames
424 		 */
425 		ret = dwc2_find_multi_uframe(hsotg, qh);
426 	}
427 	return ret;
428 }
429 
430 /**
431  * dwc2_check_max_xfer_size() - Checks that the max transfer size allowed in a
432  * host channel is large enough to handle the maximum data transfer in a single
433  * (micro)frame for a periodic transfer
434  *
435  * @hsotg: The HCD state structure for the DWC OTG controller
436  * @qh:    QH for a periodic endpoint
437  *
438  * Return: 0 if successful, negative error code otherwise
439  */
440 static int dwc2_check_max_xfer_size(struct dwc2_hsotg *hsotg,
441 				    struct dwc2_qh *qh)
442 {
443 	u32 max_xfer_size;
444 	u32 max_channel_xfer_size;
445 	int status = 0;
446 
447 	max_xfer_size = dwc2_max_packet(qh->maxp) * dwc2_hb_mult(qh->maxp);
448 	max_channel_xfer_size = hsotg->core_params->max_transfer_size;
449 
450 	if (max_xfer_size > max_channel_xfer_size) {
451 		dev_err(hsotg->dev,
452 			"%s: Periodic xfer length %d > max xfer length for channel %d\n",
453 			__func__, max_xfer_size, max_channel_xfer_size);
454 		status = -ENOSPC;
455 	}
456 
457 	return status;
458 }
459 
460 /**
461  * dwc2_schedule_periodic() - Schedules an interrupt or isochronous transfer in
462  * the periodic schedule
463  *
464  * @hsotg: The HCD state structure for the DWC OTG controller
465  * @qh:    QH for the periodic transfer. The QH should already contain the
466  *         scheduling information.
467  *
468  * Return: 0 if successful, negative error code otherwise
469  */
470 static int dwc2_schedule_periodic(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
471 {
472 	int status;
473 
474 	if (hsotg->core_params->uframe_sched > 0) {
475 		int frame = -1;
476 
477 		status = dwc2_find_uframe(hsotg, qh);
478 		if (status == 0)
479 			frame = 7;
480 		else if (status > 0)
481 			frame = status - 1;
482 
483 		/* Set the new frame up */
484 		if (frame >= 0) {
485 			qh->sched_frame &= ~0x7;
486 			qh->sched_frame |= (frame & 7);
487 		}
488 
489 		if (status > 0)
490 			status = 0;
491 	} else {
492 		status = dwc2_periodic_channel_available(hsotg);
493 		if (status) {
494 			dev_info(hsotg->dev,
495 				 "%s: No host channel available for periodic transfer\n",
496 				 __func__);
497 			return status;
498 		}
499 
500 		status = dwc2_check_periodic_bandwidth(hsotg, qh);
501 	}
502 
503 	if (status) {
504 		dev_dbg(hsotg->dev,
505 			"%s: Insufficient periodic bandwidth for periodic transfer\n",
506 			__func__);
507 		return status;
508 	}
509 
510 	status = dwc2_check_max_xfer_size(hsotg, qh);
511 	if (status) {
512 		dev_dbg(hsotg->dev,
513 			"%s: Channel max transfer size too small for periodic transfer\n",
514 			__func__);
515 		return status;
516 	}
517 
518 	if (hsotg->core_params->dma_desc_enable > 0)
519 		/* Don't rely on SOF and start in ready schedule */
520 		list_add_tail(&qh->qh_list_entry, &hsotg->periodic_sched_ready);
521 	else
522 		/* Always start in inactive schedule */
523 		list_add_tail(&qh->qh_list_entry,
524 			      &hsotg->periodic_sched_inactive);
525 
526 	if (hsotg->core_params->uframe_sched <= 0)
527 		/* Reserve periodic channel */
528 		hsotg->periodic_channels++;
529 
530 	/* Update claimed usecs per (micro)frame */
531 	hsotg->periodic_usecs += qh->usecs;
532 
533 	return status;
534 }
535 
536 /**
537  * dwc2_deschedule_periodic() - Removes an interrupt or isochronous transfer
538  * from the periodic schedule
539  *
540  * @hsotg: The HCD state structure for the DWC OTG controller
541  * @qh:	   QH for the periodic transfer
542  */
543 static void dwc2_deschedule_periodic(struct dwc2_hsotg *hsotg,
544 				     struct dwc2_qh *qh)
545 {
546 	int i;
547 
548 	list_del_init(&qh->qh_list_entry);
549 
550 	/* Update claimed usecs per (micro)frame */
551 	hsotg->periodic_usecs -= qh->usecs;
552 
553 	if (hsotg->core_params->uframe_sched > 0) {
554 		for (i = 0; i < 8; i++) {
555 			hsotg->frame_usecs[i] += qh->frame_usecs[i];
556 			qh->frame_usecs[i] = 0;
557 		}
558 	} else {
559 		/* Release periodic channel reservation */
560 		hsotg->periodic_channels--;
561 	}
562 }
563 
564 /**
565  * dwc2_hcd_qh_add() - Adds a QH to either the non periodic or periodic
566  * schedule if it is not already in the schedule. If the QH is already in
567  * the schedule, no action is taken.
568  *
569  * @hsotg: The HCD state structure for the DWC OTG controller
570  * @qh:    The QH to add
571  *
572  * Return: 0 if successful, negative error code otherwise
573  */
574 int dwc2_hcd_qh_add(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
575 {
576 	int status;
577 	u32 intr_mask;
578 
579 	if (dbg_qh(qh))
580 		dev_vdbg(hsotg->dev, "%s()\n", __func__);
581 
582 	if (!list_empty(&qh->qh_list_entry))
583 		/* QH already in a schedule */
584 		return 0;
585 
586 	/* Add the new QH to the appropriate schedule */
587 	if (dwc2_qh_is_non_per(qh)) {
588 		/* Always start in inactive schedule */
589 		list_add_tail(&qh->qh_list_entry,
590 			      &hsotg->non_periodic_sched_inactive);
591 		return 0;
592 	}
593 
594 	status = dwc2_schedule_periodic(hsotg, qh);
595 	if (status)
596 		return status;
597 	if (!hsotg->periodic_qh_count) {
598 		intr_mask = readl(hsotg->regs + GINTMSK);
599 		intr_mask |= GINTSTS_SOF;
600 		writel(intr_mask, hsotg->regs + GINTMSK);
601 	}
602 	hsotg->periodic_qh_count++;
603 
604 	return 0;
605 }
606 
607 /**
608  * dwc2_hcd_qh_unlink() - Removes a QH from either the non-periodic or periodic
609  * schedule. Memory is not freed.
610  *
611  * @hsotg: The HCD state structure
612  * @qh:    QH to remove from schedule
613  */
614 void dwc2_hcd_qh_unlink(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
615 {
616 	u32 intr_mask;
617 
618 	dev_vdbg(hsotg->dev, "%s()\n", __func__);
619 
620 	if (list_empty(&qh->qh_list_entry))
621 		/* QH is not in a schedule */
622 		return;
623 
624 	if (dwc2_qh_is_non_per(qh)) {
625 		if (hsotg->non_periodic_qh_ptr == &qh->qh_list_entry)
626 			hsotg->non_periodic_qh_ptr =
627 					hsotg->non_periodic_qh_ptr->next;
628 		list_del_init(&qh->qh_list_entry);
629 		return;
630 	}
631 
632 	dwc2_deschedule_periodic(hsotg, qh);
633 	hsotg->periodic_qh_count--;
634 	if (!hsotg->periodic_qh_count) {
635 		intr_mask = readl(hsotg->regs + GINTMSK);
636 		intr_mask &= ~GINTSTS_SOF;
637 		writel(intr_mask, hsotg->regs + GINTMSK);
638 	}
639 }
640 
641 /*
642  * Schedule the next continuing periodic split transfer
643  */
644 static void dwc2_sched_periodic_split(struct dwc2_hsotg *hsotg,
645 				      struct dwc2_qh *qh, u16 frame_number,
646 				      int sched_next_periodic_split)
647 {
648 	u16 incr;
649 
650 	if (sched_next_periodic_split) {
651 		qh->sched_frame = frame_number;
652 		incr = dwc2_frame_num_inc(qh->start_split_frame, 1);
653 		if (dwc2_frame_num_le(frame_number, incr)) {
654 			/*
655 			 * Allow one frame to elapse after start split
656 			 * microframe before scheduling complete split, but
657 			 * DON'T if we are doing the next start split in the
658 			 * same frame for an ISOC out
659 			 */
660 			if (qh->ep_type != USB_ENDPOINT_XFER_ISOC ||
661 			    qh->ep_is_in != 0) {
662 				qh->sched_frame =
663 					dwc2_frame_num_inc(qh->sched_frame, 1);
664 			}
665 		}
666 	} else {
667 		qh->sched_frame = dwc2_frame_num_inc(qh->start_split_frame,
668 						     qh->interval);
669 		if (dwc2_frame_num_le(qh->sched_frame, frame_number))
670 			qh->sched_frame = frame_number;
671 		qh->sched_frame |= 0x7;
672 		qh->start_split_frame = qh->sched_frame;
673 	}
674 }
675 
676 /*
677  * Deactivates a QH. For non-periodic QHs, removes the QH from the active
678  * non-periodic schedule. The QH is added to the inactive non-periodic
679  * schedule if any QTDs are still attached to the QH.
680  *
681  * For periodic QHs, the QH is removed from the periodic queued schedule. If
682  * there are any QTDs still attached to the QH, the QH is added to either the
683  * periodic inactive schedule or the periodic ready schedule and its next
684  * scheduled frame is calculated. The QH is placed in the ready schedule if
685  * the scheduled frame has been reached already. Otherwise it's placed in the
686  * inactive schedule. If there are no QTDs attached to the QH, the QH is
687  * completely removed from the periodic schedule.
688  */
689 void dwc2_hcd_qh_deactivate(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
690 			    int sched_next_periodic_split)
691 {
692 	u16 frame_number;
693 
694 	if (dbg_qh(qh))
695 		dev_vdbg(hsotg->dev, "%s()\n", __func__);
696 
697 	if (dwc2_qh_is_non_per(qh)) {
698 		dwc2_hcd_qh_unlink(hsotg, qh);
699 		if (!list_empty(&qh->qtd_list))
700 			/* Add back to inactive non-periodic schedule */
701 			dwc2_hcd_qh_add(hsotg, qh);
702 		return;
703 	}
704 
705 	frame_number = dwc2_hcd_get_frame_number(hsotg);
706 
707 	if (qh->do_split) {
708 		dwc2_sched_periodic_split(hsotg, qh, frame_number,
709 					  sched_next_periodic_split);
710 	} else {
711 		qh->sched_frame = dwc2_frame_num_inc(qh->sched_frame,
712 						     qh->interval);
713 		if (dwc2_frame_num_le(qh->sched_frame, frame_number))
714 			qh->sched_frame = frame_number;
715 	}
716 
717 	if (list_empty(&qh->qtd_list)) {
718 		dwc2_hcd_qh_unlink(hsotg, qh);
719 		return;
720 	}
721 	/*
722 	 * Remove from periodic_sched_queued and move to
723 	 * appropriate queue
724 	 */
725 	if ((hsotg->core_params->uframe_sched > 0 &&
726 	     dwc2_frame_num_le(qh->sched_frame, frame_number)) ||
727 	    (hsotg->core_params->uframe_sched <= 0 &&
728 	     qh->sched_frame == frame_number))
729 		list_move(&qh->qh_list_entry, &hsotg->periodic_sched_ready);
730 	else
731 		list_move(&qh->qh_list_entry, &hsotg->periodic_sched_inactive);
732 }
733 
734 /**
735  * dwc2_hcd_qtd_init() - Initializes a QTD structure
736  *
737  * @qtd: The QTD to initialize
738  * @urb: The associated URB
739  */
740 void dwc2_hcd_qtd_init(struct dwc2_qtd *qtd, struct dwc2_hcd_urb *urb)
741 {
742 	qtd->urb = urb;
743 	if (dwc2_hcd_get_pipe_type(&urb->pipe_info) ==
744 			USB_ENDPOINT_XFER_CONTROL) {
745 		/*
746 		 * The only time the QTD data toggle is used is on the data
747 		 * phase of control transfers. This phase always starts with
748 		 * DATA1.
749 		 */
750 		qtd->data_toggle = DWC2_HC_PID_DATA1;
751 		qtd->control_phase = DWC2_CONTROL_SETUP;
752 	}
753 
754 	/* Start split */
755 	qtd->complete_split = 0;
756 	qtd->isoc_split_pos = DWC2_HCSPLT_XACTPOS_ALL;
757 	qtd->isoc_split_offset = 0;
758 	qtd->in_process = 0;
759 
760 	/* Store the qtd ptr in the urb to reference the QTD */
761 	urb->qtd = qtd;
762 }
763 
764 /**
765  * dwc2_hcd_qtd_add() - Adds a QTD to the QTD-list of a QH
766  *			Caller must hold driver lock.
767  *
768  * @hsotg:        The DWC HCD structure
769  * @qtd:          The QTD to add
770  * @qh:           Queue head to add qtd to
771  *
772  * Return: 0 if successful, negative error code otherwise
773  *
774  * If the QH to which the QTD is added is not currently scheduled, it is placed
775  * into the proper schedule based on its EP type.
776  */
777 int dwc2_hcd_qtd_add(struct dwc2_hsotg *hsotg, struct dwc2_qtd *qtd,
778 		     struct dwc2_qh *qh)
779 {
780 	int retval;
781 
782 	if (unlikely(!qh)) {
783 		dev_err(hsotg->dev, "%s: Invalid QH\n", __func__);
784 		retval = -EINVAL;
785 		goto fail;
786 	}
787 
788 	retval = dwc2_hcd_qh_add(hsotg, qh);
789 	if (retval)
790 		goto fail;
791 
792 	qtd->qh = qh;
793 	list_add_tail(&qtd->qtd_list_entry, &qh->qtd_list);
794 
795 	return 0;
796 fail:
797 	return retval;
798 }
799