xref: /openbmc/linux/drivers/usb/dwc2/hcd_queue.c (revision 8c0b9ee8)
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 static 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 if (qh->dw_align_buf)
235 		dma_free_coherent(hsotg->dev, qh->dw_align_buf_size,
236 				  qh->dw_align_buf, qh->dw_align_buf_dma);
237 	kfree(qh);
238 }
239 
240 /**
241  * dwc2_periodic_channel_available() - Checks that a channel is available for a
242  * periodic transfer
243  *
244  * @hsotg: The HCD state structure for the DWC OTG controller
245  *
246  * Return: 0 if successful, negative error code otherwise
247  */
248 static int dwc2_periodic_channel_available(struct dwc2_hsotg *hsotg)
249 {
250 	/*
251 	 * Currently assuming that there is a dedicated host channel for
252 	 * each periodic transaction plus at least one host channel for
253 	 * non-periodic transactions
254 	 */
255 	int status;
256 	int num_channels;
257 
258 	num_channels = hsotg->core_params->host_channels;
259 	if (hsotg->periodic_channels + hsotg->non_periodic_channels <
260 								num_channels
261 	    && hsotg->periodic_channels < num_channels - 1) {
262 		status = 0;
263 	} else {
264 		dev_dbg(hsotg->dev,
265 			"%s: Total channels: %d, Periodic: %d, "
266 			"Non-periodic: %d\n", __func__, num_channels,
267 			hsotg->periodic_channels, hsotg->non_periodic_channels);
268 		status = -ENOSPC;
269 	}
270 
271 	return status;
272 }
273 
274 /**
275  * dwc2_check_periodic_bandwidth() - Checks that there is sufficient bandwidth
276  * for the specified QH in the periodic schedule
277  *
278  * @hsotg: The HCD state structure for the DWC OTG controller
279  * @qh:    QH containing periodic bandwidth required
280  *
281  * Return: 0 if successful, negative error code otherwise
282  *
283  * For simplicity, this calculation assumes that all the transfers in the
284  * periodic schedule may occur in the same (micro)frame
285  */
286 static int dwc2_check_periodic_bandwidth(struct dwc2_hsotg *hsotg,
287 					 struct dwc2_qh *qh)
288 {
289 	int status;
290 	s16 max_claimed_usecs;
291 
292 	status = 0;
293 
294 	if (qh->dev_speed == USB_SPEED_HIGH || qh->do_split) {
295 		/*
296 		 * High speed mode
297 		 * Max periodic usecs is 80% x 125 usec = 100 usec
298 		 */
299 		max_claimed_usecs = 100 - qh->usecs;
300 	} else {
301 		/*
302 		 * Full speed mode
303 		 * Max periodic usecs is 90% x 1000 usec = 900 usec
304 		 */
305 		max_claimed_usecs = 900 - qh->usecs;
306 	}
307 
308 	if (hsotg->periodic_usecs > max_claimed_usecs) {
309 		dev_err(hsotg->dev,
310 			"%s: already claimed usecs %d, required usecs %d\n",
311 			__func__, hsotg->periodic_usecs, qh->usecs);
312 		status = -ENOSPC;
313 	}
314 
315 	return status;
316 }
317 
318 /**
319  * Microframe scheduler
320  * track the total use in hsotg->frame_usecs
321  * keep each qh use in qh->frame_usecs
322  * when surrendering the qh then donate the time back
323  */
324 static const unsigned short max_uframe_usecs[] = {
325 	100, 100, 100, 100, 100, 100, 30, 0
326 };
327 
328 void dwc2_hcd_init_usecs(struct dwc2_hsotg *hsotg)
329 {
330 	int i;
331 
332 	for (i = 0; i < 8; i++)
333 		hsotg->frame_usecs[i] = max_uframe_usecs[i];
334 }
335 
336 static int dwc2_find_single_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
337 {
338 	unsigned short utime = qh->usecs;
339 	int i;
340 
341 	for (i = 0; i < 8; i++) {
342 		/* At the start hsotg->frame_usecs[i] = max_uframe_usecs[i] */
343 		if (utime <= hsotg->frame_usecs[i]) {
344 			hsotg->frame_usecs[i] -= utime;
345 			qh->frame_usecs[i] += utime;
346 			return i;
347 		}
348 	}
349 	return -ENOSPC;
350 }
351 
352 /*
353  * use this for FS apps that can span multiple uframes
354  */
355 static int dwc2_find_multi_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
356 {
357 	unsigned short utime = qh->usecs;
358 	unsigned short xtime;
359 	int t_left;
360 	int i;
361 	int j;
362 	int k;
363 
364 	for (i = 0; i < 8; i++) {
365 		if (hsotg->frame_usecs[i] <= 0)
366 			continue;
367 
368 		/*
369 		 * we need n consecutive slots so use j as a start slot
370 		 * j plus j+1 must be enough time (for now)
371 		 */
372 		xtime = hsotg->frame_usecs[i];
373 		for (j = i + 1; j < 8; j++) {
374 			/*
375 			 * if we add this frame remaining time to xtime we may
376 			 * be OK, if not we need to test j for a complete frame
377 			 */
378 			if (xtime + hsotg->frame_usecs[j] < utime) {
379 				if (hsotg->frame_usecs[j] <
380 							max_uframe_usecs[j])
381 					continue;
382 			}
383 			if (xtime >= utime) {
384 				t_left = utime;
385 				for (k = i; k < 8; k++) {
386 					t_left -= hsotg->frame_usecs[k];
387 					if (t_left <= 0) {
388 						qh->frame_usecs[k] +=
389 							hsotg->frame_usecs[k]
390 								+ t_left;
391 						hsotg->frame_usecs[k] = -t_left;
392 						return i;
393 					} else {
394 						qh->frame_usecs[k] +=
395 							hsotg->frame_usecs[k];
396 						hsotg->frame_usecs[k] = 0;
397 					}
398 				}
399 			}
400 			/* add the frame time to x time */
401 			xtime += hsotg->frame_usecs[j];
402 			/* we must have a fully available next frame or break */
403 			if (xtime < utime &&
404 			   hsotg->frame_usecs[j] == max_uframe_usecs[j])
405 				continue;
406 		}
407 	}
408 	return -ENOSPC;
409 }
410 
411 static int dwc2_find_uframe(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
412 {
413 	int ret;
414 
415 	if (qh->dev_speed == USB_SPEED_HIGH) {
416 		/* if this is a hs transaction we need a full frame */
417 		ret = dwc2_find_single_uframe(hsotg, qh);
418 	} else {
419 		/*
420 		 * if this is a fs transaction we may need a sequence
421 		 * of frames
422 		 */
423 		ret = dwc2_find_multi_uframe(hsotg, qh);
424 	}
425 	return ret;
426 }
427 
428 /**
429  * dwc2_check_max_xfer_size() - Checks that the max transfer size allowed in a
430  * host channel is large enough to handle the maximum data transfer in a single
431  * (micro)frame for a periodic transfer
432  *
433  * @hsotg: The HCD state structure for the DWC OTG controller
434  * @qh:    QH for a periodic endpoint
435  *
436  * Return: 0 if successful, negative error code otherwise
437  */
438 static int dwc2_check_max_xfer_size(struct dwc2_hsotg *hsotg,
439 				    struct dwc2_qh *qh)
440 {
441 	u32 max_xfer_size;
442 	u32 max_channel_xfer_size;
443 	int status = 0;
444 
445 	max_xfer_size = dwc2_max_packet(qh->maxp) * dwc2_hb_mult(qh->maxp);
446 	max_channel_xfer_size = hsotg->core_params->max_transfer_size;
447 
448 	if (max_xfer_size > max_channel_xfer_size) {
449 		dev_err(hsotg->dev,
450 			"%s: Periodic xfer length %d > max xfer length for channel %d\n",
451 			__func__, max_xfer_size, max_channel_xfer_size);
452 		status = -ENOSPC;
453 	}
454 
455 	return status;
456 }
457 
458 /**
459  * dwc2_schedule_periodic() - Schedules an interrupt or isochronous transfer in
460  * the periodic schedule
461  *
462  * @hsotg: The HCD state structure for the DWC OTG controller
463  * @qh:    QH for the periodic transfer. The QH should already contain the
464  *         scheduling information.
465  *
466  * Return: 0 if successful, negative error code otherwise
467  */
468 static int dwc2_schedule_periodic(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
469 {
470 	int status;
471 
472 	if (hsotg->core_params->uframe_sched > 0) {
473 		int frame = -1;
474 
475 		status = dwc2_find_uframe(hsotg, qh);
476 		if (status == 0)
477 			frame = 7;
478 		else if (status > 0)
479 			frame = status - 1;
480 
481 		/* Set the new frame up */
482 		if (frame >= 0) {
483 			qh->sched_frame &= ~0x7;
484 			qh->sched_frame |= (frame & 7);
485 		}
486 
487 		if (status > 0)
488 			status = 0;
489 	} else {
490 		status = dwc2_periodic_channel_available(hsotg);
491 		if (status) {
492 			dev_info(hsotg->dev,
493 				 "%s: No host channel available for periodic transfer\n",
494 				 __func__);
495 			return status;
496 		}
497 
498 		status = dwc2_check_periodic_bandwidth(hsotg, qh);
499 	}
500 
501 	if (status) {
502 		dev_dbg(hsotg->dev,
503 			"%s: Insufficient periodic bandwidth for periodic transfer\n",
504 			__func__);
505 		return status;
506 	}
507 
508 	status = dwc2_check_max_xfer_size(hsotg, qh);
509 	if (status) {
510 		dev_dbg(hsotg->dev,
511 			"%s: Channel max transfer size too small for periodic transfer\n",
512 			__func__);
513 		return status;
514 	}
515 
516 	if (hsotg->core_params->dma_desc_enable > 0)
517 		/* Don't rely on SOF and start in ready schedule */
518 		list_add_tail(&qh->qh_list_entry, &hsotg->periodic_sched_ready);
519 	else
520 		/* Always start in inactive schedule */
521 		list_add_tail(&qh->qh_list_entry,
522 			      &hsotg->periodic_sched_inactive);
523 
524 	if (hsotg->core_params->uframe_sched <= 0)
525 		/* Reserve periodic channel */
526 		hsotg->periodic_channels++;
527 
528 	/* Update claimed usecs per (micro)frame */
529 	hsotg->periodic_usecs += qh->usecs;
530 
531 	return status;
532 }
533 
534 /**
535  * dwc2_deschedule_periodic() - Removes an interrupt or isochronous transfer
536  * from the periodic schedule
537  *
538  * @hsotg: The HCD state structure for the DWC OTG controller
539  * @qh:	   QH for the periodic transfer
540  */
541 static void dwc2_deschedule_periodic(struct dwc2_hsotg *hsotg,
542 				     struct dwc2_qh *qh)
543 {
544 	int i;
545 
546 	list_del_init(&qh->qh_list_entry);
547 
548 	/* Update claimed usecs per (micro)frame */
549 	hsotg->periodic_usecs -= qh->usecs;
550 
551 	if (hsotg->core_params->uframe_sched > 0) {
552 		for (i = 0; i < 8; i++) {
553 			hsotg->frame_usecs[i] += qh->frame_usecs[i];
554 			qh->frame_usecs[i] = 0;
555 		}
556 	} else {
557 		/* Release periodic channel reservation */
558 		hsotg->periodic_channels--;
559 	}
560 }
561 
562 /**
563  * dwc2_hcd_qh_add() - Adds a QH to either the non periodic or periodic
564  * schedule if it is not already in the schedule. If the QH is already in
565  * the schedule, no action is taken.
566  *
567  * @hsotg: The HCD state structure for the DWC OTG controller
568  * @qh:    The QH to add
569  *
570  * Return: 0 if successful, negative error code otherwise
571  */
572 int dwc2_hcd_qh_add(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
573 {
574 	int status;
575 	u32 intr_mask;
576 
577 	if (dbg_qh(qh))
578 		dev_vdbg(hsotg->dev, "%s()\n", __func__);
579 
580 	if (!list_empty(&qh->qh_list_entry))
581 		/* QH already in a schedule */
582 		return 0;
583 
584 	/* Add the new QH to the appropriate schedule */
585 	if (dwc2_qh_is_non_per(qh)) {
586 		/* Always start in inactive schedule */
587 		list_add_tail(&qh->qh_list_entry,
588 			      &hsotg->non_periodic_sched_inactive);
589 		return 0;
590 	}
591 
592 	status = dwc2_schedule_periodic(hsotg, qh);
593 	if (status)
594 		return status;
595 	if (!hsotg->periodic_qh_count) {
596 		intr_mask = readl(hsotg->regs + GINTMSK);
597 		intr_mask |= GINTSTS_SOF;
598 		writel(intr_mask, hsotg->regs + GINTMSK);
599 	}
600 	hsotg->periodic_qh_count++;
601 
602 	return 0;
603 }
604 
605 /**
606  * dwc2_hcd_qh_unlink() - Removes a QH from either the non-periodic or periodic
607  * schedule. Memory is not freed.
608  *
609  * @hsotg: The HCD state structure
610  * @qh:    QH to remove from schedule
611  */
612 void dwc2_hcd_qh_unlink(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
613 {
614 	u32 intr_mask;
615 
616 	dev_vdbg(hsotg->dev, "%s()\n", __func__);
617 
618 	if (list_empty(&qh->qh_list_entry))
619 		/* QH is not in a schedule */
620 		return;
621 
622 	if (dwc2_qh_is_non_per(qh)) {
623 		if (hsotg->non_periodic_qh_ptr == &qh->qh_list_entry)
624 			hsotg->non_periodic_qh_ptr =
625 					hsotg->non_periodic_qh_ptr->next;
626 		list_del_init(&qh->qh_list_entry);
627 		return;
628 	}
629 
630 	dwc2_deschedule_periodic(hsotg, qh);
631 	hsotg->periodic_qh_count--;
632 	if (!hsotg->periodic_qh_count) {
633 		intr_mask = readl(hsotg->regs + GINTMSK);
634 		intr_mask &= ~GINTSTS_SOF;
635 		writel(intr_mask, hsotg->regs + GINTMSK);
636 	}
637 }
638 
639 /*
640  * Schedule the next continuing periodic split transfer
641  */
642 static void dwc2_sched_periodic_split(struct dwc2_hsotg *hsotg,
643 				      struct dwc2_qh *qh, u16 frame_number,
644 				      int sched_next_periodic_split)
645 {
646 	u16 incr;
647 
648 	if (sched_next_periodic_split) {
649 		qh->sched_frame = frame_number;
650 		incr = dwc2_frame_num_inc(qh->start_split_frame, 1);
651 		if (dwc2_frame_num_le(frame_number, incr)) {
652 			/*
653 			 * Allow one frame to elapse after start split
654 			 * microframe before scheduling complete split, but
655 			 * DON'T if we are doing the next start split in the
656 			 * same frame for an ISOC out
657 			 */
658 			if (qh->ep_type != USB_ENDPOINT_XFER_ISOC ||
659 			    qh->ep_is_in != 0) {
660 				qh->sched_frame =
661 					dwc2_frame_num_inc(qh->sched_frame, 1);
662 			}
663 		}
664 	} else {
665 		qh->sched_frame = dwc2_frame_num_inc(qh->start_split_frame,
666 						     qh->interval);
667 		if (dwc2_frame_num_le(qh->sched_frame, frame_number))
668 			qh->sched_frame = frame_number;
669 		qh->sched_frame |= 0x7;
670 		qh->start_split_frame = qh->sched_frame;
671 	}
672 }
673 
674 /*
675  * Deactivates a QH. For non-periodic QHs, removes the QH from the active
676  * non-periodic schedule. The QH is added to the inactive non-periodic
677  * schedule if any QTDs are still attached to the QH.
678  *
679  * For periodic QHs, the QH is removed from the periodic queued schedule. If
680  * there are any QTDs still attached to the QH, the QH is added to either the
681  * periodic inactive schedule or the periodic ready schedule and its next
682  * scheduled frame is calculated. The QH is placed in the ready schedule if
683  * the scheduled frame has been reached already. Otherwise it's placed in the
684  * inactive schedule. If there are no QTDs attached to the QH, the QH is
685  * completely removed from the periodic schedule.
686  */
687 void dwc2_hcd_qh_deactivate(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
688 			    int sched_next_periodic_split)
689 {
690 	u16 frame_number;
691 
692 	if (dbg_qh(qh))
693 		dev_vdbg(hsotg->dev, "%s()\n", __func__);
694 
695 	if (dwc2_qh_is_non_per(qh)) {
696 		dwc2_hcd_qh_unlink(hsotg, qh);
697 		if (!list_empty(&qh->qtd_list))
698 			/* Add back to inactive non-periodic schedule */
699 			dwc2_hcd_qh_add(hsotg, qh);
700 		return;
701 	}
702 
703 	frame_number = dwc2_hcd_get_frame_number(hsotg);
704 
705 	if (qh->do_split) {
706 		dwc2_sched_periodic_split(hsotg, qh, frame_number,
707 					  sched_next_periodic_split);
708 	} else {
709 		qh->sched_frame = dwc2_frame_num_inc(qh->sched_frame,
710 						     qh->interval);
711 		if (dwc2_frame_num_le(qh->sched_frame, frame_number))
712 			qh->sched_frame = frame_number;
713 	}
714 
715 	if (list_empty(&qh->qtd_list)) {
716 		dwc2_hcd_qh_unlink(hsotg, qh);
717 		return;
718 	}
719 	/*
720 	 * Remove from periodic_sched_queued and move to
721 	 * appropriate queue
722 	 */
723 	if ((hsotg->core_params->uframe_sched > 0 &&
724 	     dwc2_frame_num_le(qh->sched_frame, frame_number)) ||
725 	    (hsotg->core_params->uframe_sched <= 0 &&
726 	     qh->sched_frame == frame_number))
727 		list_move(&qh->qh_list_entry, &hsotg->periodic_sched_ready);
728 	else
729 		list_move(&qh->qh_list_entry, &hsotg->periodic_sched_inactive);
730 }
731 
732 /**
733  * dwc2_hcd_qtd_init() - Initializes a QTD structure
734  *
735  * @qtd: The QTD to initialize
736  * @urb: The associated URB
737  */
738 void dwc2_hcd_qtd_init(struct dwc2_qtd *qtd, struct dwc2_hcd_urb *urb)
739 {
740 	qtd->urb = urb;
741 	if (dwc2_hcd_get_pipe_type(&urb->pipe_info) ==
742 			USB_ENDPOINT_XFER_CONTROL) {
743 		/*
744 		 * The only time the QTD data toggle is used is on the data
745 		 * phase of control transfers. This phase always starts with
746 		 * DATA1.
747 		 */
748 		qtd->data_toggle = DWC2_HC_PID_DATA1;
749 		qtd->control_phase = DWC2_CONTROL_SETUP;
750 	}
751 
752 	/* Start split */
753 	qtd->complete_split = 0;
754 	qtd->isoc_split_pos = DWC2_HCSPLT_XACTPOS_ALL;
755 	qtd->isoc_split_offset = 0;
756 	qtd->in_process = 0;
757 
758 	/* Store the qtd ptr in the urb to reference the QTD */
759 	urb->qtd = qtd;
760 }
761 
762 /**
763  * dwc2_hcd_qtd_add() - Adds a QTD to the QTD-list of a QH
764  *
765  * @hsotg:        The DWC HCD structure
766  * @qtd:          The QTD to add
767  * @qh:           Out parameter to return queue head
768  * @atomic_alloc: Flag to do atomic alloc if needed
769  *
770  * Return: 0 if successful, negative error code otherwise
771  *
772  * Finds the correct QH to place the QTD into. If it does not find a QH, it
773  * will create a new QH. If the QH to which the QTD is added is not currently
774  * scheduled, it is placed into the proper schedule based on its EP type.
775  */
776 int dwc2_hcd_qtd_add(struct dwc2_hsotg *hsotg, struct dwc2_qtd *qtd,
777 		     struct dwc2_qh **qh, gfp_t mem_flags)
778 {
779 	struct dwc2_hcd_urb *urb = qtd->urb;
780 	unsigned long flags;
781 	int allocated = 0;
782 	int retval;
783 
784 	/*
785 	 * Get the QH which holds the QTD-list to insert to. Create QH if it
786 	 * doesn't exist.
787 	 */
788 	if (*qh == NULL) {
789 		*qh = dwc2_hcd_qh_create(hsotg, urb, mem_flags);
790 		if (*qh == NULL)
791 			return -ENOMEM;
792 		allocated = 1;
793 	}
794 
795 	spin_lock_irqsave(&hsotg->lock, flags);
796 
797 	retval = dwc2_hcd_qh_add(hsotg, *qh);
798 	if (retval)
799 		goto fail;
800 
801 	qtd->qh = *qh;
802 	list_add_tail(&qtd->qtd_list_entry, &(*qh)->qtd_list);
803 	spin_unlock_irqrestore(&hsotg->lock, flags);
804 
805 	return 0;
806 
807 fail:
808 	if (allocated) {
809 		struct dwc2_qtd *qtd2, *qtd2_tmp;
810 		struct dwc2_qh *qh_tmp = *qh;
811 
812 		*qh = NULL;
813 		dwc2_hcd_qh_unlink(hsotg, qh_tmp);
814 
815 		/* Free each QTD in the QH's QTD list */
816 		list_for_each_entry_safe(qtd2, qtd2_tmp, &qh_tmp->qtd_list,
817 					 qtd_list_entry)
818 			dwc2_hcd_qtd_unlink_and_free(hsotg, qtd2, qh_tmp);
819 
820 		spin_unlock_irqrestore(&hsotg->lock, flags);
821 		dwc2_hcd_qh_free(hsotg, qh_tmp);
822 	} else {
823 		spin_unlock_irqrestore(&hsotg->lock, flags);
824 	}
825 
826 	return retval;
827 }
828