xref: /openbmc/linux/drivers/usb/dwc2/hcd_ddma.c (revision 680ef72a)
1 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
2 /*
3  * hcd_ddma.c - DesignWare HS OTG Controller descriptor DMA routines
4  *
5  * Copyright (C) 2004-2013 Synopsys, Inc.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The names of the above-listed copyright holders may not be used
17  *    to endorse or promote products derived from this software without
18  *    specific prior written permission.
19  *
20  * ALTERNATIVELY, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") as published by the Free Software
22  * Foundation; either version 2 of the License, or (at your option) any
23  * later version.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
26  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
27  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
29  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
30  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
32  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
33  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
34  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
35  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 /*
39  * This file contains the Descriptor DMA implementation 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 static u16 dwc2_frame_list_idx(u16 frame)
57 {
58 	return frame & (FRLISTEN_64_SIZE - 1);
59 }
60 
61 static u16 dwc2_desclist_idx_inc(u16 idx, u16 inc, u8 speed)
62 {
63 	return (idx + inc) &
64 		((speed == USB_SPEED_HIGH ? MAX_DMA_DESC_NUM_HS_ISOC :
65 		  MAX_DMA_DESC_NUM_GENERIC) - 1);
66 }
67 
68 static u16 dwc2_desclist_idx_dec(u16 idx, u16 inc, u8 speed)
69 {
70 	return (idx - inc) &
71 		((speed == USB_SPEED_HIGH ? MAX_DMA_DESC_NUM_HS_ISOC :
72 		  MAX_DMA_DESC_NUM_GENERIC) - 1);
73 }
74 
75 static u16 dwc2_max_desc_num(struct dwc2_qh *qh)
76 {
77 	return (qh->ep_type == USB_ENDPOINT_XFER_ISOC &&
78 		qh->dev_speed == USB_SPEED_HIGH) ?
79 		MAX_DMA_DESC_NUM_HS_ISOC : MAX_DMA_DESC_NUM_GENERIC;
80 }
81 
82 static u16 dwc2_frame_incr_val(struct dwc2_qh *qh)
83 {
84 	return qh->dev_speed == USB_SPEED_HIGH ?
85 	       (qh->host_interval + 8 - 1) / 8 : qh->host_interval;
86 }
87 
88 static int dwc2_desc_list_alloc(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
89 				gfp_t flags)
90 {
91 	struct kmem_cache *desc_cache;
92 
93 	if (qh->ep_type == USB_ENDPOINT_XFER_ISOC &&
94 	    qh->dev_speed == USB_SPEED_HIGH)
95 		desc_cache = hsotg->desc_hsisoc_cache;
96 	else
97 		desc_cache = hsotg->desc_gen_cache;
98 
99 	qh->desc_list_sz = sizeof(struct dwc2_dma_desc) *
100 						dwc2_max_desc_num(qh);
101 
102 	qh->desc_list = kmem_cache_zalloc(desc_cache, flags | GFP_DMA);
103 	if (!qh->desc_list)
104 		return -ENOMEM;
105 
106 	qh->desc_list_dma = dma_map_single(hsotg->dev, qh->desc_list,
107 					   qh->desc_list_sz,
108 					   DMA_TO_DEVICE);
109 
110 	qh->n_bytes = kcalloc(dwc2_max_desc_num(qh), sizeof(u32), flags);
111 	if (!qh->n_bytes) {
112 		dma_unmap_single(hsotg->dev, qh->desc_list_dma,
113 				 qh->desc_list_sz,
114 				 DMA_FROM_DEVICE);
115 		kmem_cache_free(desc_cache, qh->desc_list);
116 		qh->desc_list = NULL;
117 		return -ENOMEM;
118 	}
119 
120 	return 0;
121 }
122 
123 static void dwc2_desc_list_free(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
124 {
125 	struct kmem_cache *desc_cache;
126 
127 	if (qh->ep_type == USB_ENDPOINT_XFER_ISOC &&
128 	    qh->dev_speed == USB_SPEED_HIGH)
129 		desc_cache = hsotg->desc_hsisoc_cache;
130 	else
131 		desc_cache = hsotg->desc_gen_cache;
132 
133 	if (qh->desc_list) {
134 		dma_unmap_single(hsotg->dev, qh->desc_list_dma,
135 				 qh->desc_list_sz, DMA_FROM_DEVICE);
136 		kmem_cache_free(desc_cache, qh->desc_list);
137 		qh->desc_list = NULL;
138 	}
139 
140 	kfree(qh->n_bytes);
141 	qh->n_bytes = NULL;
142 }
143 
144 static int dwc2_frame_list_alloc(struct dwc2_hsotg *hsotg, gfp_t mem_flags)
145 {
146 	if (hsotg->frame_list)
147 		return 0;
148 
149 	hsotg->frame_list_sz = 4 * FRLISTEN_64_SIZE;
150 	hsotg->frame_list = kzalloc(hsotg->frame_list_sz, GFP_ATOMIC | GFP_DMA);
151 	if (!hsotg->frame_list)
152 		return -ENOMEM;
153 
154 	hsotg->frame_list_dma = dma_map_single(hsotg->dev, hsotg->frame_list,
155 					       hsotg->frame_list_sz,
156 					       DMA_TO_DEVICE);
157 
158 	return 0;
159 }
160 
161 static void dwc2_frame_list_free(struct dwc2_hsotg *hsotg)
162 {
163 	unsigned long flags;
164 
165 	spin_lock_irqsave(&hsotg->lock, flags);
166 
167 	if (!hsotg->frame_list) {
168 		spin_unlock_irqrestore(&hsotg->lock, flags);
169 		return;
170 	}
171 
172 	dma_unmap_single(hsotg->dev, hsotg->frame_list_dma,
173 			 hsotg->frame_list_sz, DMA_FROM_DEVICE);
174 
175 	kfree(hsotg->frame_list);
176 	hsotg->frame_list = NULL;
177 
178 	spin_unlock_irqrestore(&hsotg->lock, flags);
179 }
180 
181 static void dwc2_per_sched_enable(struct dwc2_hsotg *hsotg, u32 fr_list_en)
182 {
183 	u32 hcfg;
184 	unsigned long flags;
185 
186 	spin_lock_irqsave(&hsotg->lock, flags);
187 
188 	hcfg = dwc2_readl(hsotg->regs + HCFG);
189 	if (hcfg & HCFG_PERSCHEDENA) {
190 		/* already enabled */
191 		spin_unlock_irqrestore(&hsotg->lock, flags);
192 		return;
193 	}
194 
195 	dwc2_writel(hsotg->frame_list_dma, hsotg->regs + HFLBADDR);
196 
197 	hcfg &= ~HCFG_FRLISTEN_MASK;
198 	hcfg |= fr_list_en | HCFG_PERSCHEDENA;
199 	dev_vdbg(hsotg->dev, "Enabling Periodic schedule\n");
200 	dwc2_writel(hcfg, hsotg->regs + HCFG);
201 
202 	spin_unlock_irqrestore(&hsotg->lock, flags);
203 }
204 
205 static void dwc2_per_sched_disable(struct dwc2_hsotg *hsotg)
206 {
207 	u32 hcfg;
208 	unsigned long flags;
209 
210 	spin_lock_irqsave(&hsotg->lock, flags);
211 
212 	hcfg = dwc2_readl(hsotg->regs + HCFG);
213 	if (!(hcfg & HCFG_PERSCHEDENA)) {
214 		/* already disabled */
215 		spin_unlock_irqrestore(&hsotg->lock, flags);
216 		return;
217 	}
218 
219 	hcfg &= ~HCFG_PERSCHEDENA;
220 	dev_vdbg(hsotg->dev, "Disabling Periodic schedule\n");
221 	dwc2_writel(hcfg, hsotg->regs + HCFG);
222 
223 	spin_unlock_irqrestore(&hsotg->lock, flags);
224 }
225 
226 /*
227  * Activates/Deactivates FrameList entries for the channel based on endpoint
228  * servicing period
229  */
230 static void dwc2_update_frame_list(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
231 				   int enable)
232 {
233 	struct dwc2_host_chan *chan;
234 	u16 i, j, inc;
235 
236 	if (!hsotg) {
237 		pr_err("hsotg = %p\n", hsotg);
238 		return;
239 	}
240 
241 	if (!qh->channel) {
242 		dev_err(hsotg->dev, "qh->channel = %p\n", qh->channel);
243 		return;
244 	}
245 
246 	if (!hsotg->frame_list) {
247 		dev_err(hsotg->dev, "hsotg->frame_list = %p\n",
248 			hsotg->frame_list);
249 		return;
250 	}
251 
252 	chan = qh->channel;
253 	inc = dwc2_frame_incr_val(qh);
254 	if (qh->ep_type == USB_ENDPOINT_XFER_ISOC)
255 		i = dwc2_frame_list_idx(qh->next_active_frame);
256 	else
257 		i = 0;
258 
259 	j = i;
260 	do {
261 		if (enable)
262 			hsotg->frame_list[j] |= 1 << chan->hc_num;
263 		else
264 			hsotg->frame_list[j] &= ~(1 << chan->hc_num);
265 		j = (j + inc) & (FRLISTEN_64_SIZE - 1);
266 	} while (j != i);
267 
268 	/*
269 	 * Sync frame list since controller will access it if periodic
270 	 * channel is currently enabled.
271 	 */
272 	dma_sync_single_for_device(hsotg->dev,
273 				   hsotg->frame_list_dma,
274 				   hsotg->frame_list_sz,
275 				   DMA_TO_DEVICE);
276 
277 	if (!enable)
278 		return;
279 
280 	chan->schinfo = 0;
281 	if (chan->speed == USB_SPEED_HIGH && qh->host_interval) {
282 		j = 1;
283 		/* TODO - check this */
284 		inc = (8 + qh->host_interval - 1) / qh->host_interval;
285 		for (i = 0; i < inc; i++) {
286 			chan->schinfo |= j;
287 			j = j << qh->host_interval;
288 		}
289 	} else {
290 		chan->schinfo = 0xff;
291 	}
292 }
293 
294 static void dwc2_release_channel_ddma(struct dwc2_hsotg *hsotg,
295 				      struct dwc2_qh *qh)
296 {
297 	struct dwc2_host_chan *chan = qh->channel;
298 
299 	if (dwc2_qh_is_non_per(qh)) {
300 		if (hsotg->params.uframe_sched)
301 			hsotg->available_host_channels++;
302 		else
303 			hsotg->non_periodic_channels--;
304 	} else {
305 		dwc2_update_frame_list(hsotg, qh, 0);
306 		hsotg->available_host_channels++;
307 	}
308 
309 	/*
310 	 * The condition is added to prevent double cleanup try in case of
311 	 * device disconnect. See channel cleanup in dwc2_hcd_disconnect().
312 	 */
313 	if (chan->qh) {
314 		if (!list_empty(&chan->hc_list_entry))
315 			list_del(&chan->hc_list_entry);
316 		dwc2_hc_cleanup(hsotg, chan);
317 		list_add_tail(&chan->hc_list_entry, &hsotg->free_hc_list);
318 		chan->qh = NULL;
319 	}
320 
321 	qh->channel = NULL;
322 	qh->ntd = 0;
323 
324 	if (qh->desc_list)
325 		memset(qh->desc_list, 0, sizeof(struct dwc2_dma_desc) *
326 		       dwc2_max_desc_num(qh));
327 }
328 
329 /**
330  * dwc2_hcd_qh_init_ddma() - Initializes a QH structure's Descriptor DMA
331  * related members
332  *
333  * @hsotg: The HCD state structure for the DWC OTG controller
334  * @qh:    The QH to init
335  *
336  * Return: 0 if successful, negative error code otherwise
337  *
338  * Allocates memory for the descriptor list. For the first periodic QH,
339  * allocates memory for the FrameList and enables periodic scheduling.
340  */
341 int dwc2_hcd_qh_init_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
342 			  gfp_t mem_flags)
343 {
344 	int retval;
345 
346 	if (qh->do_split) {
347 		dev_err(hsotg->dev,
348 			"SPLIT Transfers are not supported in Descriptor DMA mode.\n");
349 		retval = -EINVAL;
350 		goto err0;
351 	}
352 
353 	retval = dwc2_desc_list_alloc(hsotg, qh, mem_flags);
354 	if (retval)
355 		goto err0;
356 
357 	if (qh->ep_type == USB_ENDPOINT_XFER_ISOC ||
358 	    qh->ep_type == USB_ENDPOINT_XFER_INT) {
359 		if (!hsotg->frame_list) {
360 			retval = dwc2_frame_list_alloc(hsotg, mem_flags);
361 			if (retval)
362 				goto err1;
363 			/* Enable periodic schedule on first periodic QH */
364 			dwc2_per_sched_enable(hsotg, HCFG_FRLISTEN_64);
365 		}
366 	}
367 
368 	qh->ntd = 0;
369 	return 0;
370 
371 err1:
372 	dwc2_desc_list_free(hsotg, qh);
373 err0:
374 	return retval;
375 }
376 
377 /**
378  * dwc2_hcd_qh_free_ddma() - Frees a QH structure's Descriptor DMA related
379  * members
380  *
381  * @hsotg: The HCD state structure for the DWC OTG controller
382  * @qh:    The QH to free
383  *
384  * Frees descriptor list memory associated with the QH. If QH is periodic and
385  * the last, frees FrameList memory and disables periodic scheduling.
386  */
387 void dwc2_hcd_qh_free_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
388 {
389 	unsigned long flags;
390 
391 	dwc2_desc_list_free(hsotg, qh);
392 
393 	/*
394 	 * Channel still assigned due to some reasons.
395 	 * Seen on Isoc URB dequeue. Channel halted but no subsequent
396 	 * ChHalted interrupt to release the channel. Afterwards
397 	 * when it comes here from endpoint disable routine
398 	 * channel remains assigned.
399 	 */
400 	spin_lock_irqsave(&hsotg->lock, flags);
401 	if (qh->channel)
402 		dwc2_release_channel_ddma(hsotg, qh);
403 	spin_unlock_irqrestore(&hsotg->lock, flags);
404 
405 	if ((qh->ep_type == USB_ENDPOINT_XFER_ISOC ||
406 	     qh->ep_type == USB_ENDPOINT_XFER_INT) &&
407 	    (hsotg->params.uframe_sched ||
408 	     !hsotg->periodic_channels) && hsotg->frame_list) {
409 		dwc2_per_sched_disable(hsotg);
410 		dwc2_frame_list_free(hsotg);
411 	}
412 }
413 
414 static u8 dwc2_frame_to_desc_idx(struct dwc2_qh *qh, u16 frame_idx)
415 {
416 	if (qh->dev_speed == USB_SPEED_HIGH)
417 		/* Descriptor set (8 descriptors) index which is 8-aligned */
418 		return (frame_idx & ((MAX_DMA_DESC_NUM_HS_ISOC / 8) - 1)) * 8;
419 	else
420 		return frame_idx & (MAX_DMA_DESC_NUM_GENERIC - 1);
421 }
422 
423 /*
424  * Determine starting frame for Isochronous transfer.
425  * Few frames skipped to prevent race condition with HC.
426  */
427 static u16 dwc2_calc_starting_frame(struct dwc2_hsotg *hsotg,
428 				    struct dwc2_qh *qh, u16 *skip_frames)
429 {
430 	u16 frame;
431 
432 	hsotg->frame_number = dwc2_hcd_get_frame_number(hsotg);
433 
434 	/*
435 	 * next_active_frame is always frame number (not uFrame) both in FS
436 	 * and HS!
437 	 */
438 
439 	/*
440 	 * skip_frames is used to limit activated descriptors number
441 	 * to avoid the situation when HC services the last activated
442 	 * descriptor firstly.
443 	 * Example for FS:
444 	 * Current frame is 1, scheduled frame is 3. Since HC always fetches
445 	 * the descriptor corresponding to curr_frame+1, the descriptor
446 	 * corresponding to frame 2 will be fetched. If the number of
447 	 * descriptors is max=64 (or greather) the list will be fully programmed
448 	 * with Active descriptors and it is possible case (rare) that the
449 	 * latest descriptor(considering rollback) corresponding to frame 2 will
450 	 * be serviced first. HS case is more probable because, in fact, up to
451 	 * 11 uframes (16 in the code) may be skipped.
452 	 */
453 	if (qh->dev_speed == USB_SPEED_HIGH) {
454 		/*
455 		 * Consider uframe counter also, to start xfer asap. If half of
456 		 * the frame elapsed skip 2 frames otherwise just 1 frame.
457 		 * Starting descriptor index must be 8-aligned, so if the
458 		 * current frame is near to complete the next one is skipped as
459 		 * well.
460 		 */
461 		if (dwc2_micro_frame_num(hsotg->frame_number) >= 5) {
462 			*skip_frames = 2 * 8;
463 			frame = dwc2_frame_num_inc(hsotg->frame_number,
464 						   *skip_frames);
465 		} else {
466 			*skip_frames = 1 * 8;
467 			frame = dwc2_frame_num_inc(hsotg->frame_number,
468 						   *skip_frames);
469 		}
470 
471 		frame = dwc2_full_frame_num(frame);
472 	} else {
473 		/*
474 		 * Two frames are skipped for FS - the current and the next.
475 		 * But for descriptor programming, 1 frame (descriptor) is
476 		 * enough, see example above.
477 		 */
478 		*skip_frames = 1;
479 		frame = dwc2_frame_num_inc(hsotg->frame_number, 2);
480 	}
481 
482 	return frame;
483 }
484 
485 /*
486  * Calculate initial descriptor index for isochronous transfer based on
487  * scheduled frame
488  */
489 static u16 dwc2_recalc_initial_desc_idx(struct dwc2_hsotg *hsotg,
490 					struct dwc2_qh *qh)
491 {
492 	u16 frame, fr_idx, fr_idx_tmp, skip_frames;
493 
494 	/*
495 	 * With current ISOC processing algorithm the channel is being released
496 	 * when no more QTDs in the list (qh->ntd == 0). Thus this function is
497 	 * called only when qh->ntd == 0 and qh->channel == 0.
498 	 *
499 	 * So qh->channel != NULL branch is not used and just not removed from
500 	 * the source file. It is required for another possible approach which
501 	 * is, do not disable and release the channel when ISOC session
502 	 * completed, just move QH to inactive schedule until new QTD arrives.
503 	 * On new QTD, the QH moved back to 'ready' schedule, starting frame and
504 	 * therefore starting desc_index are recalculated. In this case channel
505 	 * is released only on ep_disable.
506 	 */
507 
508 	/*
509 	 * Calculate starting descriptor index. For INTERRUPT endpoint it is
510 	 * always 0.
511 	 */
512 	if (qh->channel) {
513 		frame = dwc2_calc_starting_frame(hsotg, qh, &skip_frames);
514 		/*
515 		 * Calculate initial descriptor index based on FrameList current
516 		 * bitmap and servicing period
517 		 */
518 		fr_idx_tmp = dwc2_frame_list_idx(frame);
519 		fr_idx = (FRLISTEN_64_SIZE +
520 			  dwc2_frame_list_idx(qh->next_active_frame) -
521 			  fr_idx_tmp) % dwc2_frame_incr_val(qh);
522 		fr_idx = (fr_idx + fr_idx_tmp) % FRLISTEN_64_SIZE;
523 	} else {
524 		qh->next_active_frame = dwc2_calc_starting_frame(hsotg, qh,
525 							   &skip_frames);
526 		fr_idx = dwc2_frame_list_idx(qh->next_active_frame);
527 	}
528 
529 	qh->td_first = qh->td_last = dwc2_frame_to_desc_idx(qh, fr_idx);
530 
531 	return skip_frames;
532 }
533 
534 #define ISOC_URB_GIVEBACK_ASAP
535 
536 #define MAX_ISOC_XFER_SIZE_FS	1023
537 #define MAX_ISOC_XFER_SIZE_HS	3072
538 #define DESCNUM_THRESHOLD	4
539 
540 static void dwc2_fill_host_isoc_dma_desc(struct dwc2_hsotg *hsotg,
541 					 struct dwc2_qtd *qtd,
542 					 struct dwc2_qh *qh, u32 max_xfer_size,
543 					 u16 idx)
544 {
545 	struct dwc2_dma_desc *dma_desc = &qh->desc_list[idx];
546 	struct dwc2_hcd_iso_packet_desc *frame_desc;
547 
548 	memset(dma_desc, 0, sizeof(*dma_desc));
549 	frame_desc = &qtd->urb->iso_descs[qtd->isoc_frame_index_last];
550 
551 	if (frame_desc->length > max_xfer_size)
552 		qh->n_bytes[idx] = max_xfer_size;
553 	else
554 		qh->n_bytes[idx] = frame_desc->length;
555 
556 	dma_desc->buf = (u32)(qtd->urb->dma + frame_desc->offset);
557 	dma_desc->status = qh->n_bytes[idx] << HOST_DMA_ISOC_NBYTES_SHIFT &
558 			   HOST_DMA_ISOC_NBYTES_MASK;
559 
560 	/* Set active bit */
561 	dma_desc->status |= HOST_DMA_A;
562 
563 	qh->ntd++;
564 	qtd->isoc_frame_index_last++;
565 
566 #ifdef ISOC_URB_GIVEBACK_ASAP
567 	/* Set IOC for each descriptor corresponding to last frame of URB */
568 	if (qtd->isoc_frame_index_last == qtd->urb->packet_count)
569 		dma_desc->status |= HOST_DMA_IOC;
570 #endif
571 
572 	dma_sync_single_for_device(hsotg->dev,
573 				   qh->desc_list_dma +
574 			(idx * sizeof(struct dwc2_dma_desc)),
575 			sizeof(struct dwc2_dma_desc),
576 			DMA_TO_DEVICE);
577 }
578 
579 static void dwc2_init_isoc_dma_desc(struct dwc2_hsotg *hsotg,
580 				    struct dwc2_qh *qh, u16 skip_frames)
581 {
582 	struct dwc2_qtd *qtd;
583 	u32 max_xfer_size;
584 	u16 idx, inc, n_desc = 0, ntd_max = 0;
585 	u16 cur_idx;
586 	u16 next_idx;
587 
588 	idx = qh->td_last;
589 	inc = qh->host_interval;
590 	hsotg->frame_number = dwc2_hcd_get_frame_number(hsotg);
591 	cur_idx = dwc2_frame_list_idx(hsotg->frame_number);
592 	next_idx = dwc2_desclist_idx_inc(qh->td_last, inc, qh->dev_speed);
593 
594 	/*
595 	 * Ensure current frame number didn't overstep last scheduled
596 	 * descriptor. If it happens, the only way to recover is to move
597 	 * qh->td_last to current frame number + 1.
598 	 * So that next isoc descriptor will be scheduled on frame number + 1
599 	 * and not on a past frame.
600 	 */
601 	if (dwc2_frame_idx_num_gt(cur_idx, next_idx) || (cur_idx == next_idx)) {
602 		if (inc < 32) {
603 			dev_vdbg(hsotg->dev,
604 				 "current frame number overstep last descriptor\n");
605 			qh->td_last = dwc2_desclist_idx_inc(cur_idx, inc,
606 							    qh->dev_speed);
607 			idx = qh->td_last;
608 		}
609 	}
610 
611 	if (qh->host_interval) {
612 		ntd_max = (dwc2_max_desc_num(qh) + qh->host_interval - 1) /
613 				qh->host_interval;
614 		if (skip_frames && !qh->channel)
615 			ntd_max -= skip_frames / qh->host_interval;
616 	}
617 
618 	max_xfer_size = qh->dev_speed == USB_SPEED_HIGH ?
619 			MAX_ISOC_XFER_SIZE_HS : MAX_ISOC_XFER_SIZE_FS;
620 
621 	list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry) {
622 		if (qtd->in_process &&
623 		    qtd->isoc_frame_index_last ==
624 		    qtd->urb->packet_count)
625 			continue;
626 
627 		qtd->isoc_td_first = idx;
628 		while (qh->ntd < ntd_max && qtd->isoc_frame_index_last <
629 						qtd->urb->packet_count) {
630 			dwc2_fill_host_isoc_dma_desc(hsotg, qtd, qh,
631 						     max_xfer_size, idx);
632 			idx = dwc2_desclist_idx_inc(idx, inc, qh->dev_speed);
633 			n_desc++;
634 		}
635 		qtd->isoc_td_last = idx;
636 		qtd->in_process = 1;
637 	}
638 
639 	qh->td_last = idx;
640 
641 #ifdef ISOC_URB_GIVEBACK_ASAP
642 	/* Set IOC for last descriptor if descriptor list is full */
643 	if (qh->ntd == ntd_max) {
644 		idx = dwc2_desclist_idx_dec(qh->td_last, inc, qh->dev_speed);
645 		qh->desc_list[idx].status |= HOST_DMA_IOC;
646 		dma_sync_single_for_device(hsotg->dev,
647 					   qh->desc_list_dma + (idx *
648 					   sizeof(struct dwc2_dma_desc)),
649 					   sizeof(struct dwc2_dma_desc),
650 					   DMA_TO_DEVICE);
651 	}
652 #else
653 	/*
654 	 * Set IOC bit only for one descriptor. Always try to be ahead of HW
655 	 * processing, i.e. on IOC generation driver activates next descriptor
656 	 * but core continues to process descriptors following the one with IOC
657 	 * set.
658 	 */
659 
660 	if (n_desc > DESCNUM_THRESHOLD)
661 		/*
662 		 * Move IOC "up". Required even if there is only one QTD
663 		 * in the list, because QTDs might continue to be queued,
664 		 * but during the activation it was only one queued.
665 		 * Actually more than one QTD might be in the list if this
666 		 * function called from XferCompletion - QTDs was queued during
667 		 * HW processing of the previous descriptor chunk.
668 		 */
669 		idx = dwc2_desclist_idx_dec(idx, inc * ((qh->ntd + 1) / 2),
670 					    qh->dev_speed);
671 	else
672 		/*
673 		 * Set the IOC for the latest descriptor if either number of
674 		 * descriptors is not greater than threshold or no more new
675 		 * descriptors activated
676 		 */
677 		idx = dwc2_desclist_idx_dec(qh->td_last, inc, qh->dev_speed);
678 
679 	qh->desc_list[idx].status |= HOST_DMA_IOC;
680 	dma_sync_single_for_device(hsotg->dev,
681 				   qh->desc_list_dma +
682 				   (idx * sizeof(struct dwc2_dma_desc)),
683 				   sizeof(struct dwc2_dma_desc),
684 				   DMA_TO_DEVICE);
685 #endif
686 }
687 
688 static void dwc2_fill_host_dma_desc(struct dwc2_hsotg *hsotg,
689 				    struct dwc2_host_chan *chan,
690 				    struct dwc2_qtd *qtd, struct dwc2_qh *qh,
691 				    int n_desc)
692 {
693 	struct dwc2_dma_desc *dma_desc = &qh->desc_list[n_desc];
694 	int len = chan->xfer_len;
695 
696 	if (len > HOST_DMA_NBYTES_LIMIT - (chan->max_packet - 1))
697 		len = HOST_DMA_NBYTES_LIMIT - (chan->max_packet - 1);
698 
699 	if (chan->ep_is_in) {
700 		int num_packets;
701 
702 		if (len > 0 && chan->max_packet)
703 			num_packets = (len + chan->max_packet - 1)
704 					/ chan->max_packet;
705 		else
706 			/* Need 1 packet for transfer length of 0 */
707 			num_packets = 1;
708 
709 		/* Always program an integral # of packets for IN transfers */
710 		len = num_packets * chan->max_packet;
711 	}
712 
713 	dma_desc->status = len << HOST_DMA_NBYTES_SHIFT & HOST_DMA_NBYTES_MASK;
714 	qh->n_bytes[n_desc] = len;
715 
716 	if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL &&
717 	    qtd->control_phase == DWC2_CONTROL_SETUP)
718 		dma_desc->status |= HOST_DMA_SUP;
719 
720 	dma_desc->buf = (u32)chan->xfer_dma;
721 
722 	dma_sync_single_for_device(hsotg->dev,
723 				   qh->desc_list_dma +
724 				   (n_desc * sizeof(struct dwc2_dma_desc)),
725 				   sizeof(struct dwc2_dma_desc),
726 				   DMA_TO_DEVICE);
727 
728 	/*
729 	 * Last (or only) descriptor of IN transfer with actual size less
730 	 * than MaxPacket
731 	 */
732 	if (len > chan->xfer_len) {
733 		chan->xfer_len = 0;
734 	} else {
735 		chan->xfer_dma += len;
736 		chan->xfer_len -= len;
737 	}
738 }
739 
740 static void dwc2_init_non_isoc_dma_desc(struct dwc2_hsotg *hsotg,
741 					struct dwc2_qh *qh)
742 {
743 	struct dwc2_qtd *qtd;
744 	struct dwc2_host_chan *chan = qh->channel;
745 	int n_desc = 0;
746 
747 	dev_vdbg(hsotg->dev, "%s(): qh=%p dma=%08lx len=%d\n", __func__, qh,
748 		 (unsigned long)chan->xfer_dma, chan->xfer_len);
749 
750 	/*
751 	 * Start with chan->xfer_dma initialized in assign_and_init_hc(), then
752 	 * if SG transfer consists of multiple URBs, this pointer is re-assigned
753 	 * to the buffer of the currently processed QTD. For non-SG request
754 	 * there is always one QTD active.
755 	 */
756 
757 	list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry) {
758 		dev_vdbg(hsotg->dev, "qtd=%p\n", qtd);
759 
760 		if (n_desc) {
761 			/* SG request - more than 1 QTD */
762 			chan->xfer_dma = qtd->urb->dma +
763 					qtd->urb->actual_length;
764 			chan->xfer_len = qtd->urb->length -
765 					qtd->urb->actual_length;
766 			dev_vdbg(hsotg->dev, "buf=%08lx len=%d\n",
767 				 (unsigned long)chan->xfer_dma, chan->xfer_len);
768 		}
769 
770 		qtd->n_desc = 0;
771 		do {
772 			if (n_desc > 1) {
773 				qh->desc_list[n_desc - 1].status |= HOST_DMA_A;
774 				dev_vdbg(hsotg->dev,
775 					 "set A bit in desc %d (%p)\n",
776 					 n_desc - 1,
777 					 &qh->desc_list[n_desc - 1]);
778 				dma_sync_single_for_device(hsotg->dev,
779 							   qh->desc_list_dma +
780 					((n_desc - 1) *
781 					sizeof(struct dwc2_dma_desc)),
782 					sizeof(struct dwc2_dma_desc),
783 					DMA_TO_DEVICE);
784 			}
785 			dwc2_fill_host_dma_desc(hsotg, chan, qtd, qh, n_desc);
786 			dev_vdbg(hsotg->dev,
787 				 "desc %d (%p) buf=%08x status=%08x\n",
788 				 n_desc, &qh->desc_list[n_desc],
789 				 qh->desc_list[n_desc].buf,
790 				 qh->desc_list[n_desc].status);
791 			qtd->n_desc++;
792 			n_desc++;
793 		} while (chan->xfer_len > 0 &&
794 			 n_desc != MAX_DMA_DESC_NUM_GENERIC);
795 
796 		dev_vdbg(hsotg->dev, "n_desc=%d\n", n_desc);
797 		qtd->in_process = 1;
798 		if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL)
799 			break;
800 		if (n_desc == MAX_DMA_DESC_NUM_GENERIC)
801 			break;
802 	}
803 
804 	if (n_desc) {
805 		qh->desc_list[n_desc - 1].status |=
806 				HOST_DMA_IOC | HOST_DMA_EOL | HOST_DMA_A;
807 		dev_vdbg(hsotg->dev, "set IOC/EOL/A bits in desc %d (%p)\n",
808 			 n_desc - 1, &qh->desc_list[n_desc - 1]);
809 		dma_sync_single_for_device(hsotg->dev,
810 					   qh->desc_list_dma + (n_desc - 1) *
811 					   sizeof(struct dwc2_dma_desc),
812 					   sizeof(struct dwc2_dma_desc),
813 					   DMA_TO_DEVICE);
814 		if (n_desc > 1) {
815 			qh->desc_list[0].status |= HOST_DMA_A;
816 			dev_vdbg(hsotg->dev, "set A bit in desc 0 (%p)\n",
817 				 &qh->desc_list[0]);
818 			dma_sync_single_for_device(hsotg->dev,
819 						   qh->desc_list_dma,
820 					sizeof(struct dwc2_dma_desc),
821 					DMA_TO_DEVICE);
822 		}
823 		chan->ntd = n_desc;
824 	}
825 }
826 
827 /**
828  * dwc2_hcd_start_xfer_ddma() - Starts a transfer in Descriptor DMA mode
829  *
830  * @hsotg: The HCD state structure for the DWC OTG controller
831  * @qh:    The QH to init
832  *
833  * Return: 0 if successful, negative error code otherwise
834  *
835  * For Control and Bulk endpoints, initializes descriptor list and starts the
836  * transfer. For Interrupt and Isochronous endpoints, initializes descriptor
837  * list then updates FrameList, marking appropriate entries as active.
838  *
839  * For Isochronous endpoints the starting descriptor index is calculated based
840  * on the scheduled frame, but only on the first transfer descriptor within a
841  * session. Then the transfer is started via enabling the channel.
842  *
843  * For Isochronous endpoints the channel is not halted on XferComplete
844  * interrupt so remains assigned to the endpoint(QH) until session is done.
845  */
846 void dwc2_hcd_start_xfer_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
847 {
848 	/* Channel is already assigned */
849 	struct dwc2_host_chan *chan = qh->channel;
850 	u16 skip_frames = 0;
851 
852 	switch (chan->ep_type) {
853 	case USB_ENDPOINT_XFER_CONTROL:
854 	case USB_ENDPOINT_XFER_BULK:
855 		dwc2_init_non_isoc_dma_desc(hsotg, qh);
856 		dwc2_hc_start_transfer_ddma(hsotg, chan);
857 		break;
858 	case USB_ENDPOINT_XFER_INT:
859 		dwc2_init_non_isoc_dma_desc(hsotg, qh);
860 		dwc2_update_frame_list(hsotg, qh, 1);
861 		dwc2_hc_start_transfer_ddma(hsotg, chan);
862 		break;
863 	case USB_ENDPOINT_XFER_ISOC:
864 		if (!qh->ntd)
865 			skip_frames = dwc2_recalc_initial_desc_idx(hsotg, qh);
866 		dwc2_init_isoc_dma_desc(hsotg, qh, skip_frames);
867 
868 		if (!chan->xfer_started) {
869 			dwc2_update_frame_list(hsotg, qh, 1);
870 
871 			/*
872 			 * Always set to max, instead of actual size. Otherwise
873 			 * ntd will be changed with channel being enabled. Not
874 			 * recommended.
875 			 */
876 			chan->ntd = dwc2_max_desc_num(qh);
877 
878 			/* Enable channel only once for ISOC */
879 			dwc2_hc_start_transfer_ddma(hsotg, chan);
880 		}
881 
882 		break;
883 	default:
884 		break;
885 	}
886 }
887 
888 #define DWC2_CMPL_DONE		1
889 #define DWC2_CMPL_STOP		2
890 
891 static int dwc2_cmpl_host_isoc_dma_desc(struct dwc2_hsotg *hsotg,
892 					struct dwc2_host_chan *chan,
893 					struct dwc2_qtd *qtd,
894 					struct dwc2_qh *qh, u16 idx)
895 {
896 	struct dwc2_dma_desc *dma_desc;
897 	struct dwc2_hcd_iso_packet_desc *frame_desc;
898 	u16 remain = 0;
899 	int rc = 0;
900 
901 	if (!qtd->urb)
902 		return -EINVAL;
903 
904 	dma_sync_single_for_cpu(hsotg->dev, qh->desc_list_dma + (idx *
905 				sizeof(struct dwc2_dma_desc)),
906 				sizeof(struct dwc2_dma_desc),
907 				DMA_FROM_DEVICE);
908 
909 	dma_desc = &qh->desc_list[idx];
910 
911 	frame_desc = &qtd->urb->iso_descs[qtd->isoc_frame_index_last];
912 	dma_desc->buf = (u32)(qtd->urb->dma + frame_desc->offset);
913 	if (chan->ep_is_in)
914 		remain = (dma_desc->status & HOST_DMA_ISOC_NBYTES_MASK) >>
915 			 HOST_DMA_ISOC_NBYTES_SHIFT;
916 
917 	if ((dma_desc->status & HOST_DMA_STS_MASK) == HOST_DMA_STS_PKTERR) {
918 		/*
919 		 * XactError, or unable to complete all the transactions
920 		 * in the scheduled micro-frame/frame, both indicated by
921 		 * HOST_DMA_STS_PKTERR
922 		 */
923 		qtd->urb->error_count++;
924 		frame_desc->actual_length = qh->n_bytes[idx] - remain;
925 		frame_desc->status = -EPROTO;
926 	} else {
927 		/* Success */
928 		frame_desc->actual_length = qh->n_bytes[idx] - remain;
929 		frame_desc->status = 0;
930 	}
931 
932 	if (++qtd->isoc_frame_index == qtd->urb->packet_count) {
933 		/*
934 		 * urb->status is not used for isoc transfers here. The
935 		 * individual frame_desc status are used instead.
936 		 */
937 		dwc2_host_complete(hsotg, qtd, 0);
938 		dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
939 
940 		/*
941 		 * This check is necessary because urb_dequeue can be called
942 		 * from urb complete callback (sound driver for example). All
943 		 * pending URBs are dequeued there, so no need for further
944 		 * processing.
945 		 */
946 		if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE)
947 			return -1;
948 		rc = DWC2_CMPL_DONE;
949 	}
950 
951 	qh->ntd--;
952 
953 	/* Stop if IOC requested descriptor reached */
954 	if (dma_desc->status & HOST_DMA_IOC)
955 		rc = DWC2_CMPL_STOP;
956 
957 	return rc;
958 }
959 
960 static void dwc2_complete_isoc_xfer_ddma(struct dwc2_hsotg *hsotg,
961 					 struct dwc2_host_chan *chan,
962 					 enum dwc2_halt_status halt_status)
963 {
964 	struct dwc2_hcd_iso_packet_desc *frame_desc;
965 	struct dwc2_qtd *qtd, *qtd_tmp;
966 	struct dwc2_qh *qh;
967 	u16 idx;
968 	int rc;
969 
970 	qh = chan->qh;
971 	idx = qh->td_first;
972 
973 	if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE) {
974 		list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry)
975 			qtd->in_process = 0;
976 		return;
977 	}
978 
979 	if (halt_status == DWC2_HC_XFER_AHB_ERR ||
980 	    halt_status == DWC2_HC_XFER_BABBLE_ERR) {
981 		/*
982 		 * Channel is halted in these error cases, considered as serious
983 		 * issues.
984 		 * Complete all URBs marking all frames as failed, irrespective
985 		 * whether some of the descriptors (frames) succeeded or not.
986 		 * Pass error code to completion routine as well, to update
987 		 * urb->status, some of class drivers might use it to stop
988 		 * queing transfer requests.
989 		 */
990 		int err = halt_status == DWC2_HC_XFER_AHB_ERR ?
991 			  -EIO : -EOVERFLOW;
992 
993 		list_for_each_entry_safe(qtd, qtd_tmp, &qh->qtd_list,
994 					 qtd_list_entry) {
995 			if (qtd->urb) {
996 				for (idx = 0; idx < qtd->urb->packet_count;
997 				     idx++) {
998 					frame_desc = &qtd->urb->iso_descs[idx];
999 					frame_desc->status = err;
1000 				}
1001 
1002 				dwc2_host_complete(hsotg, qtd, err);
1003 			}
1004 
1005 			dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
1006 		}
1007 
1008 		return;
1009 	}
1010 
1011 	list_for_each_entry_safe(qtd, qtd_tmp, &qh->qtd_list, qtd_list_entry) {
1012 		if (!qtd->in_process)
1013 			break;
1014 
1015 		/*
1016 		 * Ensure idx corresponds to descriptor where first urb of this
1017 		 * qtd was added. In fact, during isoc desc init, dwc2 may skip
1018 		 * an index if current frame number is already over this index.
1019 		 */
1020 		if (idx != qtd->isoc_td_first) {
1021 			dev_vdbg(hsotg->dev,
1022 				 "try to complete %d instead of %d\n",
1023 				 idx, qtd->isoc_td_first);
1024 			idx = qtd->isoc_td_first;
1025 		}
1026 
1027 		do {
1028 			struct dwc2_qtd *qtd_next;
1029 			u16 cur_idx;
1030 
1031 			rc = dwc2_cmpl_host_isoc_dma_desc(hsotg, chan, qtd, qh,
1032 							  idx);
1033 			if (rc < 0)
1034 				return;
1035 			idx = dwc2_desclist_idx_inc(idx, qh->host_interval,
1036 						    chan->speed);
1037 			if (!rc)
1038 				continue;
1039 
1040 			if (rc == DWC2_CMPL_DONE)
1041 				break;
1042 
1043 			/* rc == DWC2_CMPL_STOP */
1044 
1045 			if (qh->host_interval >= 32)
1046 				goto stop_scan;
1047 
1048 			qh->td_first = idx;
1049 			cur_idx = dwc2_frame_list_idx(hsotg->frame_number);
1050 			qtd_next = list_first_entry(&qh->qtd_list,
1051 						    struct dwc2_qtd,
1052 						    qtd_list_entry);
1053 			if (dwc2_frame_idx_num_gt(cur_idx,
1054 						  qtd_next->isoc_td_last))
1055 				break;
1056 
1057 			goto stop_scan;
1058 
1059 		} while (idx != qh->td_first);
1060 	}
1061 
1062 stop_scan:
1063 	qh->td_first = idx;
1064 }
1065 
1066 static int dwc2_update_non_isoc_urb_state_ddma(struct dwc2_hsotg *hsotg,
1067 					       struct dwc2_host_chan *chan,
1068 					struct dwc2_qtd *qtd,
1069 					struct dwc2_dma_desc *dma_desc,
1070 					enum dwc2_halt_status halt_status,
1071 					u32 n_bytes, int *xfer_done)
1072 {
1073 	struct dwc2_hcd_urb *urb = qtd->urb;
1074 	u16 remain = 0;
1075 
1076 	if (chan->ep_is_in)
1077 		remain = (dma_desc->status & HOST_DMA_NBYTES_MASK) >>
1078 			 HOST_DMA_NBYTES_SHIFT;
1079 
1080 	dev_vdbg(hsotg->dev, "remain=%d dwc2_urb=%p\n", remain, urb);
1081 
1082 	if (halt_status == DWC2_HC_XFER_AHB_ERR) {
1083 		dev_err(hsotg->dev, "EIO\n");
1084 		urb->status = -EIO;
1085 		return 1;
1086 	}
1087 
1088 	if ((dma_desc->status & HOST_DMA_STS_MASK) == HOST_DMA_STS_PKTERR) {
1089 		switch (halt_status) {
1090 		case DWC2_HC_XFER_STALL:
1091 			dev_vdbg(hsotg->dev, "Stall\n");
1092 			urb->status = -EPIPE;
1093 			break;
1094 		case DWC2_HC_XFER_BABBLE_ERR:
1095 			dev_err(hsotg->dev, "Babble\n");
1096 			urb->status = -EOVERFLOW;
1097 			break;
1098 		case DWC2_HC_XFER_XACT_ERR:
1099 			dev_err(hsotg->dev, "XactErr\n");
1100 			urb->status = -EPROTO;
1101 			break;
1102 		default:
1103 			dev_err(hsotg->dev,
1104 				"%s: Unhandled descriptor error status (%d)\n",
1105 				__func__, halt_status);
1106 			break;
1107 		}
1108 		return 1;
1109 	}
1110 
1111 	if (dma_desc->status & HOST_DMA_A) {
1112 		dev_vdbg(hsotg->dev,
1113 			 "Active descriptor encountered on channel %d\n",
1114 			 chan->hc_num);
1115 		return 0;
1116 	}
1117 
1118 	if (chan->ep_type == USB_ENDPOINT_XFER_CONTROL) {
1119 		if (qtd->control_phase == DWC2_CONTROL_DATA) {
1120 			urb->actual_length += n_bytes - remain;
1121 			if (remain || urb->actual_length >= urb->length) {
1122 				/*
1123 				 * For Control Data stage do not set urb->status
1124 				 * to 0, to prevent URB callback. Set it when
1125 				 * Status phase is done. See below.
1126 				 */
1127 				*xfer_done = 1;
1128 			}
1129 		} else if (qtd->control_phase == DWC2_CONTROL_STATUS) {
1130 			urb->status = 0;
1131 			*xfer_done = 1;
1132 		}
1133 		/* No handling for SETUP stage */
1134 	} else {
1135 		/* BULK and INTR */
1136 		urb->actual_length += n_bytes - remain;
1137 		dev_vdbg(hsotg->dev, "length=%d actual=%d\n", urb->length,
1138 			 urb->actual_length);
1139 		if (remain || urb->actual_length >= urb->length) {
1140 			urb->status = 0;
1141 			*xfer_done = 1;
1142 		}
1143 	}
1144 
1145 	return 0;
1146 }
1147 
1148 static int dwc2_process_non_isoc_desc(struct dwc2_hsotg *hsotg,
1149 				      struct dwc2_host_chan *chan,
1150 				      int chnum, struct dwc2_qtd *qtd,
1151 				      int desc_num,
1152 				      enum dwc2_halt_status halt_status,
1153 				      int *xfer_done)
1154 {
1155 	struct dwc2_qh *qh = chan->qh;
1156 	struct dwc2_hcd_urb *urb = qtd->urb;
1157 	struct dwc2_dma_desc *dma_desc;
1158 	u32 n_bytes;
1159 	int failed;
1160 
1161 	dev_vdbg(hsotg->dev, "%s()\n", __func__);
1162 
1163 	if (!urb)
1164 		return -EINVAL;
1165 
1166 	dma_sync_single_for_cpu(hsotg->dev,
1167 				qh->desc_list_dma + (desc_num *
1168 				sizeof(struct dwc2_dma_desc)),
1169 				sizeof(struct dwc2_dma_desc),
1170 				DMA_FROM_DEVICE);
1171 
1172 	dma_desc = &qh->desc_list[desc_num];
1173 	n_bytes = qh->n_bytes[desc_num];
1174 	dev_vdbg(hsotg->dev,
1175 		 "qtd=%p dwc2_urb=%p desc_num=%d desc=%p n_bytes=%d\n",
1176 		 qtd, urb, desc_num, dma_desc, n_bytes);
1177 	failed = dwc2_update_non_isoc_urb_state_ddma(hsotg, chan, qtd, dma_desc,
1178 						     halt_status, n_bytes,
1179 						     xfer_done);
1180 	if (failed || (*xfer_done && urb->status != -EINPROGRESS)) {
1181 		dwc2_host_complete(hsotg, qtd, urb->status);
1182 		dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
1183 		dev_vdbg(hsotg->dev, "failed=%1x xfer_done=%1x\n",
1184 			 failed, *xfer_done);
1185 		return failed;
1186 	}
1187 
1188 	if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL) {
1189 		switch (qtd->control_phase) {
1190 		case DWC2_CONTROL_SETUP:
1191 			if (urb->length > 0)
1192 				qtd->control_phase = DWC2_CONTROL_DATA;
1193 			else
1194 				qtd->control_phase = DWC2_CONTROL_STATUS;
1195 			dev_vdbg(hsotg->dev,
1196 				 "  Control setup transaction done\n");
1197 			break;
1198 		case DWC2_CONTROL_DATA:
1199 			if (*xfer_done) {
1200 				qtd->control_phase = DWC2_CONTROL_STATUS;
1201 				dev_vdbg(hsotg->dev,
1202 					 "  Control data transfer done\n");
1203 			} else if (desc_num + 1 == qtd->n_desc) {
1204 				/*
1205 				 * Last descriptor for Control data stage which
1206 				 * is not completed yet
1207 				 */
1208 				dwc2_hcd_save_data_toggle(hsotg, chan, chnum,
1209 							  qtd);
1210 			}
1211 			break;
1212 		default:
1213 			break;
1214 		}
1215 	}
1216 
1217 	return 0;
1218 }
1219 
1220 static void dwc2_complete_non_isoc_xfer_ddma(struct dwc2_hsotg *hsotg,
1221 					     struct dwc2_host_chan *chan,
1222 					     int chnum,
1223 					     enum dwc2_halt_status halt_status)
1224 {
1225 	struct list_head *qtd_item, *qtd_tmp;
1226 	struct dwc2_qh *qh = chan->qh;
1227 	struct dwc2_qtd *qtd = NULL;
1228 	int xfer_done;
1229 	int desc_num = 0;
1230 
1231 	if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE) {
1232 		list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry)
1233 			qtd->in_process = 0;
1234 		return;
1235 	}
1236 
1237 	list_for_each_safe(qtd_item, qtd_tmp, &qh->qtd_list) {
1238 		int i;
1239 		int qtd_desc_count;
1240 
1241 		qtd = list_entry(qtd_item, struct dwc2_qtd, qtd_list_entry);
1242 		xfer_done = 0;
1243 		qtd_desc_count = qtd->n_desc;
1244 
1245 		for (i = 0; i < qtd_desc_count; i++) {
1246 			if (dwc2_process_non_isoc_desc(hsotg, chan, chnum, qtd,
1247 						       desc_num, halt_status,
1248 						       &xfer_done)) {
1249 				qtd = NULL;
1250 				goto stop_scan;
1251 			}
1252 
1253 			desc_num++;
1254 		}
1255 	}
1256 
1257 stop_scan:
1258 	if (qh->ep_type != USB_ENDPOINT_XFER_CONTROL) {
1259 		/*
1260 		 * Resetting the data toggle for bulk and interrupt endpoints
1261 		 * in case of stall. See handle_hc_stall_intr().
1262 		 */
1263 		if (halt_status == DWC2_HC_XFER_STALL)
1264 			qh->data_toggle = DWC2_HC_PID_DATA0;
1265 		else
1266 			dwc2_hcd_save_data_toggle(hsotg, chan, chnum, NULL);
1267 	}
1268 
1269 	if (halt_status == DWC2_HC_XFER_COMPLETE) {
1270 		if (chan->hcint & HCINTMSK_NYET) {
1271 			/*
1272 			 * Got a NYET on the last transaction of the transfer.
1273 			 * It means that the endpoint should be in the PING
1274 			 * state at the beginning of the next transfer.
1275 			 */
1276 			qh->ping_state = 1;
1277 		}
1278 	}
1279 }
1280 
1281 /**
1282  * dwc2_hcd_complete_xfer_ddma() - Scans the descriptor list, updates URB's
1283  * status and calls completion routine for the URB if it's done. Called from
1284  * interrupt handlers.
1285  *
1286  * @hsotg:       The HCD state structure for the DWC OTG controller
1287  * @chan:        Host channel the transfer is completed on
1288  * @chnum:       Index of Host channel registers
1289  * @halt_status: Reason the channel is being halted or just XferComplete
1290  *               for isochronous transfers
1291  *
1292  * Releases the channel to be used by other transfers.
1293  * In case of Isochronous endpoint the channel is not halted until the end of
1294  * the session, i.e. QTD list is empty.
1295  * If periodic channel released the FrameList is updated accordingly.
1296  * Calls transaction selection routines to activate pending transfers.
1297  */
1298 void dwc2_hcd_complete_xfer_ddma(struct dwc2_hsotg *hsotg,
1299 				 struct dwc2_host_chan *chan, int chnum,
1300 				 enum dwc2_halt_status halt_status)
1301 {
1302 	struct dwc2_qh *qh = chan->qh;
1303 	int continue_isoc_xfer = 0;
1304 	enum dwc2_transaction_type tr_type;
1305 
1306 	if (chan->ep_type == USB_ENDPOINT_XFER_ISOC) {
1307 		dwc2_complete_isoc_xfer_ddma(hsotg, chan, halt_status);
1308 
1309 		/* Release the channel if halted or session completed */
1310 		if (halt_status != DWC2_HC_XFER_COMPLETE ||
1311 		    list_empty(&qh->qtd_list)) {
1312 			struct dwc2_qtd *qtd, *qtd_tmp;
1313 
1314 			/*
1315 			 * Kill all remainings QTDs since channel has been
1316 			 * halted.
1317 			 */
1318 			list_for_each_entry_safe(qtd, qtd_tmp,
1319 						 &qh->qtd_list,
1320 						 qtd_list_entry) {
1321 				dwc2_host_complete(hsotg, qtd,
1322 						   -ECONNRESET);
1323 				dwc2_hcd_qtd_unlink_and_free(hsotg,
1324 							     qtd, qh);
1325 			}
1326 
1327 			/* Halt the channel if session completed */
1328 			if (halt_status == DWC2_HC_XFER_COMPLETE)
1329 				dwc2_hc_halt(hsotg, chan, halt_status);
1330 			dwc2_release_channel_ddma(hsotg, qh);
1331 			dwc2_hcd_qh_unlink(hsotg, qh);
1332 		} else {
1333 			/* Keep in assigned schedule to continue transfer */
1334 			list_move_tail(&qh->qh_list_entry,
1335 				       &hsotg->periodic_sched_assigned);
1336 			/*
1337 			 * If channel has been halted during giveback of urb
1338 			 * then prevent any new scheduling.
1339 			 */
1340 			if (!chan->halt_status)
1341 				continue_isoc_xfer = 1;
1342 		}
1343 		/*
1344 		 * Todo: Consider the case when period exceeds FrameList size.
1345 		 * Frame Rollover interrupt should be used.
1346 		 */
1347 	} else {
1348 		/*
1349 		 * Scan descriptor list to complete the URB(s), then release
1350 		 * the channel
1351 		 */
1352 		dwc2_complete_non_isoc_xfer_ddma(hsotg, chan, chnum,
1353 						 halt_status);
1354 		dwc2_release_channel_ddma(hsotg, qh);
1355 		dwc2_hcd_qh_unlink(hsotg, qh);
1356 
1357 		if (!list_empty(&qh->qtd_list)) {
1358 			/*
1359 			 * Add back to inactive non-periodic schedule on normal
1360 			 * completion
1361 			 */
1362 			dwc2_hcd_qh_add(hsotg, qh);
1363 		}
1364 	}
1365 
1366 	tr_type = dwc2_hcd_select_transactions(hsotg);
1367 	if (tr_type != DWC2_TRANSACTION_NONE || continue_isoc_xfer) {
1368 		if (continue_isoc_xfer) {
1369 			if (tr_type == DWC2_TRANSACTION_NONE)
1370 				tr_type = DWC2_TRANSACTION_PERIODIC;
1371 			else if (tr_type == DWC2_TRANSACTION_NON_PERIODIC)
1372 				tr_type = DWC2_TRANSACTION_ALL;
1373 		}
1374 		dwc2_hcd_queue_transactions(hsotg, tr_type);
1375 	}
1376 }
1377