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
8/*
9 * This file contains the Descriptor DMA implementation for Host mode
10 */
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/spinlock.h>
14#include <linux/interrupt.h>
15#include <linux/dma-mapping.h>
16#include <linux/io.h>
17#include <linux/slab.h>
18#include <linux/usb.h>
19
20#include <linux/usb/hcd.h>
21#include <linux/usb/ch11.h>
22
23#include "core.h"
24#include "hcd.h"
25
26static u16 dwc2_frame_list_idx(u16 frame)
27{
28 return frame & (FRLISTEN_64_SIZE - 1);
29}
30
31static u16 dwc2_desclist_idx_inc(u16 idx, u16 inc, u8 speed)
32{
33 return (idx + inc) &
34 ((speed == USB_SPEED_HIGH ? MAX_DMA_DESC_NUM_HS_ISOC :
35 MAX_DMA_DESC_NUM_GENERIC) - 1);
36}
37
38static u16 dwc2_desclist_idx_dec(u16 idx, u16 inc, u8 speed)
39{
40 return (idx - inc) &
41 ((speed == USB_SPEED_HIGH ? MAX_DMA_DESC_NUM_HS_ISOC :
42 MAX_DMA_DESC_NUM_GENERIC) - 1);
43}
44
45static u16 dwc2_max_desc_num(struct dwc2_qh *qh)
46{
47 return (qh->ep_type == USB_ENDPOINT_XFER_ISOC &&
48 qh->dev_speed == USB_SPEED_HIGH) ?
49 MAX_DMA_DESC_NUM_HS_ISOC : MAX_DMA_DESC_NUM_GENERIC;
50}
51
52static u16 dwc2_frame_incr_val(struct dwc2_qh *qh)
53{
54 return qh->dev_speed == USB_SPEED_HIGH ?
55 (qh->host_interval + 8 - 1) / 8 : qh->host_interval;
56}
57
58static int dwc2_desc_list_alloc(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
59 gfp_t flags)
60{
61 struct kmem_cache *desc_cache;
62
63 if (qh->ep_type == USB_ENDPOINT_XFER_ISOC &&
64 qh->dev_speed == USB_SPEED_HIGH)
65 desc_cache = hsotg->desc_hsisoc_cache;
66 else
67 desc_cache = hsotg->desc_gen_cache;
68
69 qh->desc_list_sz = sizeof(struct dwc2_dma_desc) *
70 dwc2_max_desc_num(qh);
71
72 qh->desc_list = kmem_cache_zalloc(k: desc_cache, flags: flags | GFP_DMA);
73 if (!qh->desc_list)
74 return -ENOMEM;
75
76 qh->desc_list_dma = dma_map_single(hsotg->dev, qh->desc_list,
77 qh->desc_list_sz,
78 DMA_TO_DEVICE);
79
80 qh->n_bytes = kcalloc(n: dwc2_max_desc_num(qh), size: sizeof(u32), flags);
81 if (!qh->n_bytes) {
82 dma_unmap_single(hsotg->dev, qh->desc_list_dma,
83 qh->desc_list_sz,
84 DMA_FROM_DEVICE);
85 kmem_cache_free(s: desc_cache, objp: qh->desc_list);
86 qh->desc_list = NULL;
87 return -ENOMEM;
88 }
89
90 return 0;
91}
92
93static void dwc2_desc_list_free(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
94{
95 struct kmem_cache *desc_cache;
96
97 if (qh->ep_type == USB_ENDPOINT_XFER_ISOC &&
98 qh->dev_speed == USB_SPEED_HIGH)
99 desc_cache = hsotg->desc_hsisoc_cache;
100 else
101 desc_cache = hsotg->desc_gen_cache;
102
103 if (qh->desc_list) {
104 dma_unmap_single(hsotg->dev, qh->desc_list_dma,
105 qh->desc_list_sz, DMA_FROM_DEVICE);
106 kmem_cache_free(s: desc_cache, objp: qh->desc_list);
107 qh->desc_list = NULL;
108 }
109
110 kfree(objp: qh->n_bytes);
111 qh->n_bytes = NULL;
112}
113
114static int dwc2_frame_list_alloc(struct dwc2_hsotg *hsotg, gfp_t mem_flags)
115{
116 if (hsotg->frame_list)
117 return 0;
118
119 hsotg->frame_list_sz = 4 * FRLISTEN_64_SIZE;
120 hsotg->frame_list = kzalloc(size: hsotg->frame_list_sz, GFP_ATOMIC | GFP_DMA);
121 if (!hsotg->frame_list)
122 return -ENOMEM;
123
124 hsotg->frame_list_dma = dma_map_single(hsotg->dev, hsotg->frame_list,
125 hsotg->frame_list_sz,
126 DMA_TO_DEVICE);
127
128 return 0;
129}
130
131static void dwc2_frame_list_free(struct dwc2_hsotg *hsotg)
132{
133 unsigned long flags;
134
135 spin_lock_irqsave(&hsotg->lock, flags);
136
137 if (!hsotg->frame_list) {
138 spin_unlock_irqrestore(lock: &hsotg->lock, flags);
139 return;
140 }
141
142 dma_unmap_single(hsotg->dev, hsotg->frame_list_dma,
143 hsotg->frame_list_sz, DMA_FROM_DEVICE);
144
145 kfree(objp: hsotg->frame_list);
146 hsotg->frame_list = NULL;
147
148 spin_unlock_irqrestore(lock: &hsotg->lock, flags);
149}
150
151static void dwc2_per_sched_enable(struct dwc2_hsotg *hsotg, u32 fr_list_en)
152{
153 u32 hcfg;
154 unsigned long flags;
155
156 spin_lock_irqsave(&hsotg->lock, flags);
157
158 hcfg = dwc2_readl(hsotg, HCFG);
159 if (hcfg & HCFG_PERSCHEDENA) {
160 /* already enabled */
161 spin_unlock_irqrestore(lock: &hsotg->lock, flags);
162 return;
163 }
164
165 dwc2_writel(hsotg, value: hsotg->frame_list_dma, HFLBADDR);
166
167 hcfg &= ~HCFG_FRLISTEN_MASK;
168 hcfg |= fr_list_en | HCFG_PERSCHEDENA;
169 dev_vdbg(hsotg->dev, "Enabling Periodic schedule\n");
170 dwc2_writel(hsotg, value: hcfg, HCFG);
171
172 spin_unlock_irqrestore(lock: &hsotg->lock, flags);
173}
174
175static void dwc2_per_sched_disable(struct dwc2_hsotg *hsotg)
176{
177 u32 hcfg;
178 unsigned long flags;
179
180 spin_lock_irqsave(&hsotg->lock, flags);
181
182 hcfg = dwc2_readl(hsotg, HCFG);
183 if (!(hcfg & HCFG_PERSCHEDENA)) {
184 /* already disabled */
185 spin_unlock_irqrestore(lock: &hsotg->lock, flags);
186 return;
187 }
188
189 hcfg &= ~HCFG_PERSCHEDENA;
190 dev_vdbg(hsotg->dev, "Disabling Periodic schedule\n");
191 dwc2_writel(hsotg, value: hcfg, HCFG);
192
193 spin_unlock_irqrestore(lock: &hsotg->lock, flags);
194}
195
196/*
197 * Activates/Deactivates FrameList entries for the channel based on endpoint
198 * servicing period
199 */
200static void dwc2_update_frame_list(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
201 int enable)
202{
203 struct dwc2_host_chan *chan;
204 u16 i, j, inc;
205
206 if (!hsotg) {
207 pr_err("hsotg = %p\n", hsotg);
208 return;
209 }
210
211 if (!qh->channel) {
212 dev_err(hsotg->dev, "qh->channel = %p\n", qh->channel);
213 return;
214 }
215
216 if (!hsotg->frame_list) {
217 dev_err(hsotg->dev, "hsotg->frame_list = %p\n",
218 hsotg->frame_list);
219 return;
220 }
221
222 chan = qh->channel;
223 inc = dwc2_frame_incr_val(qh);
224 if (qh->ep_type == USB_ENDPOINT_XFER_ISOC)
225 i = dwc2_frame_list_idx(frame: qh->next_active_frame);
226 else
227 i = 0;
228
229 j = i;
230 do {
231 if (enable)
232 hsotg->frame_list[j] |= 1 << chan->hc_num;
233 else
234 hsotg->frame_list[j] &= ~(1 << chan->hc_num);
235 j = (j + inc) & (FRLISTEN_64_SIZE - 1);
236 } while (j != i);
237
238 /*
239 * Sync frame list since controller will access it if periodic
240 * channel is currently enabled.
241 */
242 dma_sync_single_for_device(dev: hsotg->dev,
243 addr: hsotg->frame_list_dma,
244 size: hsotg->frame_list_sz,
245 dir: DMA_TO_DEVICE);
246
247 if (!enable)
248 return;
249
250 chan->schinfo = 0;
251 if (chan->speed == USB_SPEED_HIGH && qh->host_interval) {
252 j = 1;
253 /* TODO - check this */
254 inc = (8 + qh->host_interval - 1) / qh->host_interval;
255 for (i = 0; i < inc; i++) {
256 chan->schinfo |= j;
257 j = j << qh->host_interval;
258 }
259 } else {
260 chan->schinfo = 0xff;
261 }
262}
263
264static void dwc2_release_channel_ddma(struct dwc2_hsotg *hsotg,
265 struct dwc2_qh *qh)
266{
267 struct dwc2_host_chan *chan = qh->channel;
268
269 if (dwc2_qh_is_non_per(qh)) {
270 if (hsotg->params.uframe_sched)
271 hsotg->available_host_channels++;
272 else
273 hsotg->non_periodic_channels--;
274 } else {
275 dwc2_update_frame_list(hsotg, qh, enable: 0);
276 hsotg->available_host_channels++;
277 }
278
279 /*
280 * The condition is added to prevent double cleanup try in case of
281 * device disconnect. See channel cleanup in dwc2_hcd_disconnect().
282 */
283 if (chan->qh) {
284 if (!list_empty(head: &chan->hc_list_entry))
285 list_del(entry: &chan->hc_list_entry);
286 dwc2_hc_cleanup(hsotg, chan);
287 list_add_tail(new: &chan->hc_list_entry, head: &hsotg->free_hc_list);
288 chan->qh = NULL;
289 }
290
291 qh->channel = NULL;
292 qh->ntd = 0;
293
294 if (qh->desc_list)
295 memset(qh->desc_list, 0, sizeof(struct dwc2_dma_desc) *
296 dwc2_max_desc_num(qh));
297}
298
299/**
300 * dwc2_hcd_qh_init_ddma() - Initializes a QH structure's Descriptor DMA
301 * related members
302 *
303 * @hsotg: The HCD state structure for the DWC OTG controller
304 * @qh: The QH to init
305 * @mem_flags: Indicates the type of memory allocation
306 *
307 * Return: 0 if successful, negative error code otherwise
308 *
309 * Allocates memory for the descriptor list. For the first periodic QH,
310 * allocates memory for the FrameList and enables periodic scheduling.
311 */
312int dwc2_hcd_qh_init_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
313 gfp_t mem_flags)
314{
315 int retval;
316
317 if (qh->do_split) {
318 dev_err(hsotg->dev,
319 "SPLIT Transfers are not supported in Descriptor DMA mode.\n");
320 retval = -EINVAL;
321 goto err0;
322 }
323
324 retval = dwc2_desc_list_alloc(hsotg, qh, flags: mem_flags);
325 if (retval)
326 goto err0;
327
328 if (qh->ep_type == USB_ENDPOINT_XFER_ISOC ||
329 qh->ep_type == USB_ENDPOINT_XFER_INT) {
330 if (!hsotg->frame_list) {
331 retval = dwc2_frame_list_alloc(hsotg, mem_flags);
332 if (retval)
333 goto err1;
334 /* Enable periodic schedule on first periodic QH */
335 dwc2_per_sched_enable(hsotg, HCFG_FRLISTEN_64);
336 }
337 }
338
339 qh->ntd = 0;
340 return 0;
341
342err1:
343 dwc2_desc_list_free(hsotg, qh);
344err0:
345 return retval;
346}
347
348/**
349 * dwc2_hcd_qh_free_ddma() - Frees a QH structure's Descriptor DMA related
350 * members
351 *
352 * @hsotg: The HCD state structure for the DWC OTG controller
353 * @qh: The QH to free
354 *
355 * Frees descriptor list memory associated with the QH. If QH is periodic and
356 * the last, frees FrameList memory and disables periodic scheduling.
357 */
358void dwc2_hcd_qh_free_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
359{
360 unsigned long flags;
361
362 dwc2_desc_list_free(hsotg, qh);
363
364 /*
365 * Channel still assigned due to some reasons.
366 * Seen on Isoc URB dequeue. Channel halted but no subsequent
367 * ChHalted interrupt to release the channel. Afterwards
368 * when it comes here from endpoint disable routine
369 * channel remains assigned.
370 */
371 spin_lock_irqsave(&hsotg->lock, flags);
372 if (qh->channel)
373 dwc2_release_channel_ddma(hsotg, qh);
374 spin_unlock_irqrestore(lock: &hsotg->lock, flags);
375
376 if ((qh->ep_type == USB_ENDPOINT_XFER_ISOC ||
377 qh->ep_type == USB_ENDPOINT_XFER_INT) &&
378 (hsotg->params.uframe_sched ||
379 !hsotg->periodic_channels) && hsotg->frame_list) {
380 dwc2_per_sched_disable(hsotg);
381 dwc2_frame_list_free(hsotg);
382 }
383}
384
385static u8 dwc2_frame_to_desc_idx(struct dwc2_qh *qh, u16 frame_idx)
386{
387 if (qh->dev_speed == USB_SPEED_HIGH)
388 /* Descriptor set (8 descriptors) index which is 8-aligned */
389 return (frame_idx & ((MAX_DMA_DESC_NUM_HS_ISOC / 8) - 1)) * 8;
390 else
391 return frame_idx & (MAX_DMA_DESC_NUM_GENERIC - 1);
392}
393
394/*
395 * Determine starting frame for Isochronous transfer.
396 * Few frames skipped to prevent race condition with HC.
397 */
398static u16 dwc2_calc_starting_frame(struct dwc2_hsotg *hsotg,
399 struct dwc2_qh *qh, u16 *skip_frames)
400{
401 u16 frame;
402
403 hsotg->frame_number = dwc2_hcd_get_frame_number(hsotg);
404
405 /*
406 * next_active_frame is always frame number (not uFrame) both in FS
407 * and HS!
408 */
409
410 /*
411 * skip_frames is used to limit activated descriptors number
412 * to avoid the situation when HC services the last activated
413 * descriptor firstly.
414 * Example for FS:
415 * Current frame is 1, scheduled frame is 3. Since HC always fetches
416 * the descriptor corresponding to curr_frame+1, the descriptor
417 * corresponding to frame 2 will be fetched. If the number of
418 * descriptors is max=64 (or greather) the list will be fully programmed
419 * with Active descriptors and it is possible case (rare) that the
420 * latest descriptor(considering rollback) corresponding to frame 2 will
421 * be serviced first. HS case is more probable because, in fact, up to
422 * 11 uframes (16 in the code) may be skipped.
423 */
424 if (qh->dev_speed == USB_SPEED_HIGH) {
425 /*
426 * Consider uframe counter also, to start xfer asap. If half of
427 * the frame elapsed skip 2 frames otherwise just 1 frame.
428 * Starting descriptor index must be 8-aligned, so if the
429 * current frame is near to complete the next one is skipped as
430 * well.
431 */
432 if (dwc2_micro_frame_num(frame: hsotg->frame_number) >= 5) {
433 *skip_frames = 2 * 8;
434 frame = dwc2_frame_num_inc(frame: hsotg->frame_number,
435 inc: *skip_frames);
436 } else {
437 *skip_frames = 1 * 8;
438 frame = dwc2_frame_num_inc(frame: hsotg->frame_number,
439 inc: *skip_frames);
440 }
441
442 frame = dwc2_full_frame_num(frame);
443 } else {
444 /*
445 * Two frames are skipped for FS - the current and the next.
446 * But for descriptor programming, 1 frame (descriptor) is
447 * enough, see example above.
448 */
449 *skip_frames = 1;
450 frame = dwc2_frame_num_inc(frame: hsotg->frame_number, inc: 2);
451 }
452
453 return frame;
454}
455
456/*
457 * Calculate initial descriptor index for isochronous transfer based on
458 * scheduled frame
459 */
460static u16 dwc2_recalc_initial_desc_idx(struct dwc2_hsotg *hsotg,
461 struct dwc2_qh *qh)
462{
463 u16 frame, fr_idx, fr_idx_tmp, skip_frames;
464
465 /*
466 * With current ISOC processing algorithm the channel is being released
467 * when no more QTDs in the list (qh->ntd == 0). Thus this function is
468 * called only when qh->ntd == 0 and qh->channel == 0.
469 *
470 * So qh->channel != NULL branch is not used and just not removed from
471 * the source file. It is required for another possible approach which
472 * is, do not disable and release the channel when ISOC session
473 * completed, just move QH to inactive schedule until new QTD arrives.
474 * On new QTD, the QH moved back to 'ready' schedule, starting frame and
475 * therefore starting desc_index are recalculated. In this case channel
476 * is released only on ep_disable.
477 */
478
479 /*
480 * Calculate starting descriptor index. For INTERRUPT endpoint it is
481 * always 0.
482 */
483 if (qh->channel) {
484 frame = dwc2_calc_starting_frame(hsotg, qh, skip_frames: &skip_frames);
485 /*
486 * Calculate initial descriptor index based on FrameList current
487 * bitmap and servicing period
488 */
489 fr_idx_tmp = dwc2_frame_list_idx(frame);
490 fr_idx = (FRLISTEN_64_SIZE +
491 dwc2_frame_list_idx(frame: qh->next_active_frame) -
492 fr_idx_tmp) % dwc2_frame_incr_val(qh);
493 fr_idx = (fr_idx + fr_idx_tmp) % FRLISTEN_64_SIZE;
494 } else {
495 qh->next_active_frame = dwc2_calc_starting_frame(hsotg, qh,
496 skip_frames: &skip_frames);
497 fr_idx = dwc2_frame_list_idx(frame: qh->next_active_frame);
498 }
499
500 qh->td_first = qh->td_last = dwc2_frame_to_desc_idx(qh, frame_idx: fr_idx);
501
502 return skip_frames;
503}
504
505#define ISOC_URB_GIVEBACK_ASAP
506
507#define MAX_ISOC_XFER_SIZE_FS 1023
508#define MAX_ISOC_XFER_SIZE_HS 3072
509#define DESCNUM_THRESHOLD 4
510
511static void dwc2_fill_host_isoc_dma_desc(struct dwc2_hsotg *hsotg,
512 struct dwc2_qtd *qtd,
513 struct dwc2_qh *qh, u32 max_xfer_size,
514 u16 idx)
515{
516 struct dwc2_dma_desc *dma_desc = &qh->desc_list[idx];
517 struct dwc2_hcd_iso_packet_desc *frame_desc;
518
519 memset(dma_desc, 0, sizeof(*dma_desc));
520 frame_desc = &qtd->urb->iso_descs[qtd->isoc_frame_index_last];
521
522 if (frame_desc->length > max_xfer_size)
523 qh->n_bytes[idx] = max_xfer_size;
524 else
525 qh->n_bytes[idx] = frame_desc->length;
526
527 dma_desc->buf = (u32)(qtd->urb->dma + frame_desc->offset);
528 dma_desc->status = qh->n_bytes[idx] << HOST_DMA_ISOC_NBYTES_SHIFT &
529 HOST_DMA_ISOC_NBYTES_MASK;
530
531 /* Set active bit */
532 dma_desc->status |= HOST_DMA_A;
533
534 qh->ntd++;
535 qtd->isoc_frame_index_last++;
536
537#ifdef ISOC_URB_GIVEBACK_ASAP
538 /* Set IOC for each descriptor corresponding to last frame of URB */
539 if (qtd->isoc_frame_index_last == qtd->urb->packet_count)
540 dma_desc->status |= HOST_DMA_IOC;
541#endif
542
543 dma_sync_single_for_device(dev: hsotg->dev,
544 addr: qh->desc_list_dma +
545 (idx * sizeof(struct dwc2_dma_desc)),
546 size: sizeof(struct dwc2_dma_desc),
547 dir: DMA_TO_DEVICE);
548}
549
550static void dwc2_init_isoc_dma_desc(struct dwc2_hsotg *hsotg,
551 struct dwc2_qh *qh, u16 skip_frames)
552{
553 struct dwc2_qtd *qtd;
554 u32 max_xfer_size;
555 u16 idx, inc, n_desc = 0, ntd_max = 0;
556 u16 cur_idx;
557 u16 next_idx;
558
559 idx = qh->td_last;
560 inc = qh->host_interval;
561 hsotg->frame_number = dwc2_hcd_get_frame_number(hsotg);
562 cur_idx = dwc2_frame_list_idx(frame: hsotg->frame_number);
563 next_idx = dwc2_desclist_idx_inc(idx: qh->td_last, inc, speed: qh->dev_speed);
564
565 /*
566 * Ensure current frame number didn't overstep last scheduled
567 * descriptor. If it happens, the only way to recover is to move
568 * qh->td_last to current frame number + 1.
569 * So that next isoc descriptor will be scheduled on frame number + 1
570 * and not on a past frame.
571 */
572 if (dwc2_frame_idx_num_gt(fr_idx1: cur_idx, fr_idx2: next_idx) || (cur_idx == next_idx)) {
573 if (inc < 32) {
574 dev_vdbg(hsotg->dev,
575 "current frame number overstep last descriptor\n");
576 qh->td_last = dwc2_desclist_idx_inc(idx: cur_idx, inc,
577 speed: qh->dev_speed);
578 idx = qh->td_last;
579 }
580 }
581
582 if (qh->host_interval) {
583 ntd_max = (dwc2_max_desc_num(qh) + qh->host_interval - 1) /
584 qh->host_interval;
585 if (skip_frames && !qh->channel)
586 ntd_max -= skip_frames / qh->host_interval;
587 }
588
589 max_xfer_size = qh->dev_speed == USB_SPEED_HIGH ?
590 MAX_ISOC_XFER_SIZE_HS : MAX_ISOC_XFER_SIZE_FS;
591
592 list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry) {
593 if (qtd->in_process &&
594 qtd->isoc_frame_index_last ==
595 qtd->urb->packet_count)
596 continue;
597
598 qtd->isoc_td_first = idx;
599 while (qh->ntd < ntd_max && qtd->isoc_frame_index_last <
600 qtd->urb->packet_count) {
601 dwc2_fill_host_isoc_dma_desc(hsotg, qtd, qh,
602 max_xfer_size, idx);
603 idx = dwc2_desclist_idx_inc(idx, inc, speed: qh->dev_speed);
604 n_desc++;
605 }
606 qtd->isoc_td_last = idx;
607 qtd->in_process = 1;
608 }
609
610 qh->td_last = idx;
611
612#ifdef ISOC_URB_GIVEBACK_ASAP
613 /* Set IOC for last descriptor if descriptor list is full */
614 if (qh->ntd == ntd_max) {
615 idx = dwc2_desclist_idx_dec(idx: qh->td_last, inc, speed: qh->dev_speed);
616 qh->desc_list[idx].status |= HOST_DMA_IOC;
617 dma_sync_single_for_device(dev: hsotg->dev,
618 addr: qh->desc_list_dma + (idx *
619 sizeof(struct dwc2_dma_desc)),
620 size: sizeof(struct dwc2_dma_desc),
621 dir: DMA_TO_DEVICE);
622 }
623#else
624 /*
625 * Set IOC bit only for one descriptor. Always try to be ahead of HW
626 * processing, i.e. on IOC generation driver activates next descriptor
627 * but core continues to process descriptors following the one with IOC
628 * set.
629 */
630
631 if (n_desc > DESCNUM_THRESHOLD)
632 /*
633 * Move IOC "up". Required even if there is only one QTD
634 * in the list, because QTDs might continue to be queued,
635 * but during the activation it was only one queued.
636 * Actually more than one QTD might be in the list if this
637 * function called from XferCompletion - QTDs was queued during
638 * HW processing of the previous descriptor chunk.
639 */
640 idx = dwc2_desclist_idx_dec(idx, inc * ((qh->ntd + 1) / 2),
641 qh->dev_speed);
642 else
643 /*
644 * Set the IOC for the latest descriptor if either number of
645 * descriptors is not greater than threshold or no more new
646 * descriptors activated
647 */
648 idx = dwc2_desclist_idx_dec(qh->td_last, inc, qh->dev_speed);
649
650 qh->desc_list[idx].status |= HOST_DMA_IOC;
651 dma_sync_single_for_device(hsotg->dev,
652 qh->desc_list_dma +
653 (idx * sizeof(struct dwc2_dma_desc)),
654 sizeof(struct dwc2_dma_desc),
655 DMA_TO_DEVICE);
656#endif
657}
658
659static void dwc2_fill_host_dma_desc(struct dwc2_hsotg *hsotg,
660 struct dwc2_host_chan *chan,
661 struct dwc2_qtd *qtd, struct dwc2_qh *qh,
662 int n_desc)
663{
664 struct dwc2_dma_desc *dma_desc = &qh->desc_list[n_desc];
665 int len = chan->xfer_len;
666
667 if (len > HOST_DMA_NBYTES_LIMIT - (chan->max_packet - 1))
668 len = HOST_DMA_NBYTES_LIMIT - (chan->max_packet - 1);
669
670 if (chan->ep_is_in) {
671 int num_packets;
672
673 if (len > 0 && chan->max_packet)
674 num_packets = (len + chan->max_packet - 1)
675 / chan->max_packet;
676 else
677 /* Need 1 packet for transfer length of 0 */
678 num_packets = 1;
679
680 /* Always program an integral # of packets for IN transfers */
681 len = num_packets * chan->max_packet;
682 }
683
684 dma_desc->status = len << HOST_DMA_NBYTES_SHIFT & HOST_DMA_NBYTES_MASK;
685 qh->n_bytes[n_desc] = len;
686
687 if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL &&
688 qtd->control_phase == DWC2_CONTROL_SETUP)
689 dma_desc->status |= HOST_DMA_SUP;
690
691 dma_desc->buf = (u32)chan->xfer_dma;
692
693 dma_sync_single_for_device(dev: hsotg->dev,
694 addr: qh->desc_list_dma +
695 (n_desc * sizeof(struct dwc2_dma_desc)),
696 size: sizeof(struct dwc2_dma_desc),
697 dir: DMA_TO_DEVICE);
698
699 /*
700 * Last (or only) descriptor of IN transfer with actual size less
701 * than MaxPacket
702 */
703 if (len > chan->xfer_len) {
704 chan->xfer_len = 0;
705 } else {
706 chan->xfer_dma += len;
707 chan->xfer_len -= len;
708 }
709}
710
711static void dwc2_init_non_isoc_dma_desc(struct dwc2_hsotg *hsotg,
712 struct dwc2_qh *qh)
713{
714 struct dwc2_qtd *qtd;
715 struct dwc2_host_chan *chan = qh->channel;
716 int n_desc = 0;
717
718 dev_vdbg(hsotg->dev, "%s(): qh=%p dma=%08lx len=%d\n", __func__, qh,
719 (unsigned long)chan->xfer_dma, chan->xfer_len);
720
721 /*
722 * Start with chan->xfer_dma initialized in assign_and_init_hc(), then
723 * if SG transfer consists of multiple URBs, this pointer is re-assigned
724 * to the buffer of the currently processed QTD. For non-SG request
725 * there is always one QTD active.
726 */
727
728 list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry) {
729 dev_vdbg(hsotg->dev, "qtd=%p\n", qtd);
730
731 if (n_desc) {
732 /* SG request - more than 1 QTD */
733 chan->xfer_dma = qtd->urb->dma +
734 qtd->urb->actual_length;
735 chan->xfer_len = qtd->urb->length -
736 qtd->urb->actual_length;
737 dev_vdbg(hsotg->dev, "buf=%08lx len=%d\n",
738 (unsigned long)chan->xfer_dma, chan->xfer_len);
739 }
740
741 qtd->n_desc = 0;
742 do {
743 if (n_desc > 1) {
744 qh->desc_list[n_desc - 1].status |= HOST_DMA_A;
745 dev_vdbg(hsotg->dev,
746 "set A bit in desc %d (%p)\n",
747 n_desc - 1,
748 &qh->desc_list[n_desc - 1]);
749 dma_sync_single_for_device(dev: hsotg->dev,
750 addr: qh->desc_list_dma +
751 ((n_desc - 1) *
752 sizeof(struct dwc2_dma_desc)),
753 size: sizeof(struct dwc2_dma_desc),
754 dir: DMA_TO_DEVICE);
755 }
756 dwc2_fill_host_dma_desc(hsotg, chan, qtd, qh, n_desc);
757 dev_vdbg(hsotg->dev,
758 "desc %d (%p) buf=%08x status=%08x\n",
759 n_desc, &qh->desc_list[n_desc],
760 qh->desc_list[n_desc].buf,
761 qh->desc_list[n_desc].status);
762 qtd->n_desc++;
763 n_desc++;
764 } while (chan->xfer_len > 0 &&
765 n_desc != MAX_DMA_DESC_NUM_GENERIC);
766
767 dev_vdbg(hsotg->dev, "n_desc=%d\n", n_desc);
768 qtd->in_process = 1;
769 if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL)
770 break;
771 if (n_desc == MAX_DMA_DESC_NUM_GENERIC)
772 break;
773 }
774
775 if (n_desc) {
776 qh->desc_list[n_desc - 1].status |=
777 HOST_DMA_IOC | HOST_DMA_EOL | HOST_DMA_A;
778 dev_vdbg(hsotg->dev, "set IOC/EOL/A bits in desc %d (%p)\n",
779 n_desc - 1, &qh->desc_list[n_desc - 1]);
780 dma_sync_single_for_device(dev: hsotg->dev,
781 addr: qh->desc_list_dma + (n_desc - 1) *
782 sizeof(struct dwc2_dma_desc),
783 size: sizeof(struct dwc2_dma_desc),
784 dir: DMA_TO_DEVICE);
785 if (n_desc > 1) {
786 qh->desc_list[0].status |= HOST_DMA_A;
787 dev_vdbg(hsotg->dev, "set A bit in desc 0 (%p)\n",
788 &qh->desc_list[0]);
789 dma_sync_single_for_device(dev: hsotg->dev,
790 addr: qh->desc_list_dma,
791 size: sizeof(struct dwc2_dma_desc),
792 dir: DMA_TO_DEVICE);
793 }
794 chan->ntd = n_desc;
795 }
796}
797
798/**
799 * dwc2_hcd_start_xfer_ddma() - Starts a transfer in Descriptor DMA mode
800 *
801 * @hsotg: The HCD state structure for the DWC OTG controller
802 * @qh: The QH to init
803 *
804 * Return: 0 if successful, negative error code otherwise
805 *
806 * For Control and Bulk endpoints, initializes descriptor list and starts the
807 * transfer. For Interrupt and Isochronous endpoints, initializes descriptor
808 * list then updates FrameList, marking appropriate entries as active.
809 *
810 * For Isochronous endpoints the starting descriptor index is calculated based
811 * on the scheduled frame, but only on the first transfer descriptor within a
812 * session. Then the transfer is started via enabling the channel.
813 *
814 * For Isochronous endpoints the channel is not halted on XferComplete
815 * interrupt so remains assigned to the endpoint(QH) until session is done.
816 */
817void dwc2_hcd_start_xfer_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
818{
819 /* Channel is already assigned */
820 struct dwc2_host_chan *chan = qh->channel;
821 u16 skip_frames = 0;
822
823 switch (chan->ep_type) {
824 case USB_ENDPOINT_XFER_CONTROL:
825 case USB_ENDPOINT_XFER_BULK:
826 dwc2_init_non_isoc_dma_desc(hsotg, qh);
827 dwc2_hc_start_transfer_ddma(hsotg, chan);
828 break;
829 case USB_ENDPOINT_XFER_INT:
830 dwc2_init_non_isoc_dma_desc(hsotg, qh);
831 dwc2_update_frame_list(hsotg, qh, enable: 1);
832 dwc2_hc_start_transfer_ddma(hsotg, chan);
833 break;
834 case USB_ENDPOINT_XFER_ISOC:
835 if (!qh->ntd)
836 skip_frames = dwc2_recalc_initial_desc_idx(hsotg, qh);
837 dwc2_init_isoc_dma_desc(hsotg, qh, skip_frames);
838
839 if (!chan->xfer_started) {
840 dwc2_update_frame_list(hsotg, qh, enable: 1);
841
842 /*
843 * Always set to max, instead of actual size. Otherwise
844 * ntd will be changed with channel being enabled. Not
845 * recommended.
846 */
847 chan->ntd = dwc2_max_desc_num(qh);
848
849 /* Enable channel only once for ISOC */
850 dwc2_hc_start_transfer_ddma(hsotg, chan);
851 }
852
853 break;
854 default:
855 break;
856 }
857}
858
859#define DWC2_CMPL_DONE 1
860#define DWC2_CMPL_STOP 2
861
862static int dwc2_cmpl_host_isoc_dma_desc(struct dwc2_hsotg *hsotg,
863 struct dwc2_host_chan *chan,
864 struct dwc2_qtd *qtd,
865 struct dwc2_qh *qh, u16 idx)
866{
867 struct dwc2_dma_desc *dma_desc;
868 struct dwc2_hcd_iso_packet_desc *frame_desc;
869 u16 remain = 0;
870 int rc = 0;
871
872 if (!qtd->urb)
873 return -EINVAL;
874
875 dma_sync_single_for_cpu(dev: hsotg->dev, addr: qh->desc_list_dma + (idx *
876 sizeof(struct dwc2_dma_desc)),
877 size: sizeof(struct dwc2_dma_desc),
878 dir: DMA_FROM_DEVICE);
879
880 dma_desc = &qh->desc_list[idx];
881
882 frame_desc = &qtd->urb->iso_descs[qtd->isoc_frame_index_last];
883 dma_desc->buf = (u32)(qtd->urb->dma + frame_desc->offset);
884 if (chan->ep_is_in)
885 remain = (dma_desc->status & HOST_DMA_ISOC_NBYTES_MASK) >>
886 HOST_DMA_ISOC_NBYTES_SHIFT;
887
888 if ((dma_desc->status & HOST_DMA_STS_MASK) == HOST_DMA_STS_PKTERR) {
889 /*
890 * XactError, or unable to complete all the transactions
891 * in the scheduled micro-frame/frame, both indicated by
892 * HOST_DMA_STS_PKTERR
893 */
894 qtd->urb->error_count++;
895 frame_desc->actual_length = qh->n_bytes[idx] - remain;
896 frame_desc->status = -EPROTO;
897 } else {
898 /* Success */
899 frame_desc->actual_length = qh->n_bytes[idx] - remain;
900 frame_desc->status = 0;
901 }
902
903 if (++qtd->isoc_frame_index == qtd->urb->packet_count) {
904 /*
905 * urb->status is not used for isoc transfers here. The
906 * individual frame_desc status are used instead.
907 */
908 dwc2_host_complete(hsotg, qtd, status: 0);
909 dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
910
911 /*
912 * This check is necessary because urb_dequeue can be called
913 * from urb complete callback (sound driver for example). All
914 * pending URBs are dequeued there, so no need for further
915 * processing.
916 */
917 if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE)
918 return -1;
919 rc = DWC2_CMPL_DONE;
920 }
921
922 qh->ntd--;
923
924 /* Stop if IOC requested descriptor reached */
925 if (dma_desc->status & HOST_DMA_IOC)
926 rc = DWC2_CMPL_STOP;
927
928 return rc;
929}
930
931static void dwc2_complete_isoc_xfer_ddma(struct dwc2_hsotg *hsotg,
932 struct dwc2_host_chan *chan,
933 enum dwc2_halt_status halt_status)
934{
935 struct dwc2_hcd_iso_packet_desc *frame_desc;
936 struct dwc2_qtd *qtd, *qtd_tmp;
937 struct dwc2_qh *qh;
938 u16 idx;
939 int rc;
940
941 qh = chan->qh;
942 idx = qh->td_first;
943
944 if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE) {
945 list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry)
946 qtd->in_process = 0;
947 return;
948 }
949
950 if (halt_status == DWC2_HC_XFER_AHB_ERR ||
951 halt_status == DWC2_HC_XFER_BABBLE_ERR) {
952 /*
953 * Channel is halted in these error cases, considered as serious
954 * issues.
955 * Complete all URBs marking all frames as failed, irrespective
956 * whether some of the descriptors (frames) succeeded or not.
957 * Pass error code to completion routine as well, to update
958 * urb->status, some of class drivers might use it to stop
959 * queing transfer requests.
960 */
961 int err = halt_status == DWC2_HC_XFER_AHB_ERR ?
962 -EIO : -EOVERFLOW;
963
964 list_for_each_entry_safe(qtd, qtd_tmp, &qh->qtd_list,
965 qtd_list_entry) {
966 if (qtd->urb) {
967 for (idx = 0; idx < qtd->urb->packet_count;
968 idx++) {
969 frame_desc = &qtd->urb->iso_descs[idx];
970 frame_desc->status = err;
971 }
972
973 dwc2_host_complete(hsotg, qtd, status: err);
974 }
975
976 dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
977 }
978
979 return;
980 }
981
982 list_for_each_entry_safe(qtd, qtd_tmp, &qh->qtd_list, qtd_list_entry) {
983 if (!qtd->in_process)
984 break;
985
986 /*
987 * Ensure idx corresponds to descriptor where first urb of this
988 * qtd was added. In fact, during isoc desc init, dwc2 may skip
989 * an index if current frame number is already over this index.
990 */
991 if (idx != qtd->isoc_td_first) {
992 dev_vdbg(hsotg->dev,
993 "try to complete %d instead of %d\n",
994 idx, qtd->isoc_td_first);
995 idx = qtd->isoc_td_first;
996 }
997
998 do {
999 struct dwc2_qtd *qtd_next;
1000 u16 cur_idx;
1001
1002 rc = dwc2_cmpl_host_isoc_dma_desc(hsotg, chan, qtd, qh,
1003 idx);
1004 if (rc < 0)
1005 return;
1006 idx = dwc2_desclist_idx_inc(idx, inc: qh->host_interval,
1007 speed: chan->speed);
1008 if (!rc)
1009 continue;
1010
1011 if (rc == DWC2_CMPL_DONE)
1012 break;
1013
1014 /* rc == DWC2_CMPL_STOP */
1015
1016 if (qh->host_interval >= 32)
1017 goto stop_scan;
1018
1019 qh->td_first = idx;
1020 cur_idx = dwc2_frame_list_idx(frame: hsotg->frame_number);
1021 qtd_next = list_first_entry(&qh->qtd_list,
1022 struct dwc2_qtd,
1023 qtd_list_entry);
1024 if (dwc2_frame_idx_num_gt(fr_idx1: cur_idx,
1025 fr_idx2: qtd_next->isoc_td_last))
1026 break;
1027
1028 goto stop_scan;
1029
1030 } while (idx != qh->td_first);
1031 }
1032
1033stop_scan:
1034 qh->td_first = idx;
1035}
1036
1037static int dwc2_update_non_isoc_urb_state_ddma(struct dwc2_hsotg *hsotg,
1038 struct dwc2_host_chan *chan,
1039 struct dwc2_qtd *qtd,
1040 struct dwc2_dma_desc *dma_desc,
1041 enum dwc2_halt_status halt_status,
1042 u32 n_bytes, int *xfer_done)
1043{
1044 struct dwc2_hcd_urb *urb = qtd->urb;
1045 u16 remain = 0;
1046
1047 if (chan->ep_is_in)
1048 remain = (dma_desc->status & HOST_DMA_NBYTES_MASK) >>
1049 HOST_DMA_NBYTES_SHIFT;
1050
1051 dev_vdbg(hsotg->dev, "remain=%d dwc2_urb=%p\n", remain, urb);
1052
1053 if (halt_status == DWC2_HC_XFER_AHB_ERR) {
1054 dev_err(hsotg->dev, "EIO\n");
1055 urb->status = -EIO;
1056 return 1;
1057 }
1058
1059 if ((dma_desc->status & HOST_DMA_STS_MASK) == HOST_DMA_STS_PKTERR) {
1060 switch (halt_status) {
1061 case DWC2_HC_XFER_STALL:
1062 dev_vdbg(hsotg->dev, "Stall\n");
1063 urb->status = -EPIPE;
1064 break;
1065 case DWC2_HC_XFER_BABBLE_ERR:
1066 dev_err(hsotg->dev, "Babble\n");
1067 urb->status = -EOVERFLOW;
1068 break;
1069 case DWC2_HC_XFER_XACT_ERR:
1070 dev_err(hsotg->dev, "XactErr\n");
1071 urb->status = -EPROTO;
1072 break;
1073 default:
1074 dev_err(hsotg->dev,
1075 "%s: Unhandled descriptor error status (%d)\n",
1076 __func__, halt_status);
1077 break;
1078 }
1079 return 1;
1080 }
1081
1082 if (dma_desc->status & HOST_DMA_A) {
1083 dev_vdbg(hsotg->dev,
1084 "Active descriptor encountered on channel %d\n",
1085 chan->hc_num);
1086 return 0;
1087 }
1088
1089 if (chan->ep_type == USB_ENDPOINT_XFER_CONTROL) {
1090 if (qtd->control_phase == DWC2_CONTROL_DATA) {
1091 urb->actual_length += n_bytes - remain;
1092 if (remain || urb->actual_length >= urb->length) {
1093 /*
1094 * For Control Data stage do not set urb->status
1095 * to 0, to prevent URB callback. Set it when
1096 * Status phase is done. See below.
1097 */
1098 *xfer_done = 1;
1099 }
1100 } else if (qtd->control_phase == DWC2_CONTROL_STATUS) {
1101 urb->status = 0;
1102 *xfer_done = 1;
1103 }
1104 /* No handling for SETUP stage */
1105 } else {
1106 /* BULK and INTR */
1107 urb->actual_length += n_bytes - remain;
1108 dev_vdbg(hsotg->dev, "length=%d actual=%d\n", urb->length,
1109 urb->actual_length);
1110 if (remain || urb->actual_length >= urb->length) {
1111 urb->status = 0;
1112 *xfer_done = 1;
1113 }
1114 }
1115
1116 return 0;
1117}
1118
1119static int dwc2_process_non_isoc_desc(struct dwc2_hsotg *hsotg,
1120 struct dwc2_host_chan *chan,
1121 int chnum, struct dwc2_qtd *qtd,
1122 int desc_num,
1123 enum dwc2_halt_status halt_status,
1124 int *xfer_done)
1125{
1126 struct dwc2_qh *qh = chan->qh;
1127 struct dwc2_hcd_urb *urb = qtd->urb;
1128 struct dwc2_dma_desc *dma_desc;
1129 u32 n_bytes;
1130 int failed;
1131
1132 dev_vdbg(hsotg->dev, "%s()\n", __func__);
1133
1134 if (!urb)
1135 return -EINVAL;
1136
1137 dma_sync_single_for_cpu(dev: hsotg->dev,
1138 addr: qh->desc_list_dma + (desc_num *
1139 sizeof(struct dwc2_dma_desc)),
1140 size: sizeof(struct dwc2_dma_desc),
1141 dir: DMA_FROM_DEVICE);
1142
1143 dma_desc = &qh->desc_list[desc_num];
1144 n_bytes = qh->n_bytes[desc_num];
1145 dev_vdbg(hsotg->dev,
1146 "qtd=%p dwc2_urb=%p desc_num=%d desc=%p n_bytes=%d\n",
1147 qtd, urb, desc_num, dma_desc, n_bytes);
1148 failed = dwc2_update_non_isoc_urb_state_ddma(hsotg, chan, qtd, dma_desc,
1149 halt_status, n_bytes,
1150 xfer_done);
1151 if (failed || (*xfer_done && urb->status != -EINPROGRESS)) {
1152 dwc2_host_complete(hsotg, qtd, status: urb->status);
1153 dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
1154 dev_vdbg(hsotg->dev, "failed=%1x xfer_done=%1x\n",
1155 failed, *xfer_done);
1156 return failed;
1157 }
1158
1159 if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL) {
1160 switch (qtd->control_phase) {
1161 case DWC2_CONTROL_SETUP:
1162 if (urb->length > 0)
1163 qtd->control_phase = DWC2_CONTROL_DATA;
1164 else
1165 qtd->control_phase = DWC2_CONTROL_STATUS;
1166 dev_vdbg(hsotg->dev,
1167 " Control setup transaction done\n");
1168 break;
1169 case DWC2_CONTROL_DATA:
1170 if (*xfer_done) {
1171 qtd->control_phase = DWC2_CONTROL_STATUS;
1172 dev_vdbg(hsotg->dev,
1173 " Control data transfer done\n");
1174 } else if (desc_num + 1 == qtd->n_desc) {
1175 /*
1176 * Last descriptor for Control data stage which
1177 * is not completed yet
1178 */
1179 dwc2_hcd_save_data_toggle(hsotg, chan, chnum,
1180 qtd);
1181 }
1182 break;
1183 default:
1184 break;
1185 }
1186 }
1187
1188 return 0;
1189}
1190
1191static void dwc2_complete_non_isoc_xfer_ddma(struct dwc2_hsotg *hsotg,
1192 struct dwc2_host_chan *chan,
1193 int chnum,
1194 enum dwc2_halt_status halt_status)
1195{
1196 struct list_head *qtd_item, *qtd_tmp;
1197 struct dwc2_qh *qh = chan->qh;
1198 struct dwc2_qtd *qtd = NULL;
1199 int xfer_done;
1200 int desc_num = 0;
1201
1202 if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE) {
1203 list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry)
1204 qtd->in_process = 0;
1205 return;
1206 }
1207
1208 list_for_each_safe(qtd_item, qtd_tmp, &qh->qtd_list) {
1209 int i;
1210 int qtd_desc_count;
1211
1212 qtd = list_entry(qtd_item, struct dwc2_qtd, qtd_list_entry);
1213 xfer_done = 0;
1214 qtd_desc_count = qtd->n_desc;
1215
1216 for (i = 0; i < qtd_desc_count; i++) {
1217 if (dwc2_process_non_isoc_desc(hsotg, chan, chnum, qtd,
1218 desc_num, halt_status,
1219 xfer_done: &xfer_done)) {
1220 qtd = NULL;
1221 goto stop_scan;
1222 }
1223
1224 desc_num++;
1225 }
1226 }
1227
1228stop_scan:
1229 if (qh->ep_type != USB_ENDPOINT_XFER_CONTROL) {
1230 /*
1231 * Resetting the data toggle for bulk and interrupt endpoints
1232 * in case of stall. See handle_hc_stall_intr().
1233 */
1234 if (halt_status == DWC2_HC_XFER_STALL)
1235 qh->data_toggle = DWC2_HC_PID_DATA0;
1236 else
1237 dwc2_hcd_save_data_toggle(hsotg, chan, chnum, NULL);
1238 }
1239
1240 if (halt_status == DWC2_HC_XFER_COMPLETE) {
1241 if (chan->hcint & HCINTMSK_NYET) {
1242 /*
1243 * Got a NYET on the last transaction of the transfer.
1244 * It means that the endpoint should be in the PING
1245 * state at the beginning of the next transfer.
1246 */
1247 qh->ping_state = 1;
1248 }
1249 }
1250}
1251
1252/**
1253 * dwc2_hcd_complete_xfer_ddma() - Scans the descriptor list, updates URB's
1254 * status and calls completion routine for the URB if it's done. Called from
1255 * interrupt handlers.
1256 *
1257 * @hsotg: The HCD state structure for the DWC OTG controller
1258 * @chan: Host channel the transfer is completed on
1259 * @chnum: Index of Host channel registers
1260 * @halt_status: Reason the channel is being halted or just XferComplete
1261 * for isochronous transfers
1262 *
1263 * Releases the channel to be used by other transfers.
1264 * In case of Isochronous endpoint the channel is not halted until the end of
1265 * the session, i.e. QTD list is empty.
1266 * If periodic channel released the FrameList is updated accordingly.
1267 * Calls transaction selection routines to activate pending transfers.
1268 */
1269void dwc2_hcd_complete_xfer_ddma(struct dwc2_hsotg *hsotg,
1270 struct dwc2_host_chan *chan, int chnum,
1271 enum dwc2_halt_status halt_status)
1272{
1273 struct dwc2_qh *qh = chan->qh;
1274 int continue_isoc_xfer = 0;
1275 enum dwc2_transaction_type tr_type;
1276
1277 if (chan->ep_type == USB_ENDPOINT_XFER_ISOC) {
1278 dwc2_complete_isoc_xfer_ddma(hsotg, chan, halt_status);
1279
1280 /* Release the channel if halted or session completed */
1281 if (halt_status != DWC2_HC_XFER_COMPLETE ||
1282 list_empty(head: &qh->qtd_list)) {
1283 struct dwc2_qtd *qtd, *qtd_tmp;
1284
1285 /*
1286 * Kill all remainings QTDs since channel has been
1287 * halted.
1288 */
1289 list_for_each_entry_safe(qtd, qtd_tmp,
1290 &qh->qtd_list,
1291 qtd_list_entry) {
1292 dwc2_host_complete(hsotg, qtd,
1293 status: -ECONNRESET);
1294 dwc2_hcd_qtd_unlink_and_free(hsotg,
1295 qtd, qh);
1296 }
1297
1298 /* Halt the channel if session completed */
1299 if (halt_status == DWC2_HC_XFER_COMPLETE)
1300 dwc2_hc_halt(hsotg, chan, halt_status);
1301 dwc2_release_channel_ddma(hsotg, qh);
1302 dwc2_hcd_qh_unlink(hsotg, qh);
1303 } else {
1304 /* Keep in assigned schedule to continue transfer */
1305 list_move_tail(list: &qh->qh_list_entry,
1306 head: &hsotg->periodic_sched_assigned);
1307 /*
1308 * If channel has been halted during giveback of urb
1309 * then prevent any new scheduling.
1310 */
1311 if (!chan->halt_status)
1312 continue_isoc_xfer = 1;
1313 }
1314 /*
1315 * Todo: Consider the case when period exceeds FrameList size.
1316 * Frame Rollover interrupt should be used.
1317 */
1318 } else {
1319 /*
1320 * Scan descriptor list to complete the URB(s), then release
1321 * the channel
1322 */
1323 dwc2_complete_non_isoc_xfer_ddma(hsotg, chan, chnum,
1324 halt_status);
1325 dwc2_release_channel_ddma(hsotg, qh);
1326 dwc2_hcd_qh_unlink(hsotg, qh);
1327
1328 if (!list_empty(head: &qh->qtd_list)) {
1329 /*
1330 * Add back to inactive non-periodic schedule on normal
1331 * completion
1332 */
1333 dwc2_hcd_qh_add(hsotg, qh);
1334 }
1335 }
1336
1337 tr_type = dwc2_hcd_select_transactions(hsotg);
1338 if (tr_type != DWC2_TRANSACTION_NONE || continue_isoc_xfer) {
1339 if (continue_isoc_xfer) {
1340 if (tr_type == DWC2_TRANSACTION_NONE)
1341 tr_type = DWC2_TRANSACTION_PERIODIC;
1342 else if (tr_type == DWC2_TRANSACTION_NON_PERIODIC)
1343 tr_type = DWC2_TRANSACTION_ALL;
1344 }
1345 dwc2_hcd_queue_transactions(hsotg, tr_type);
1346 }
1347}
1348

source code of linux/drivers/usb/dwc2/hcd_ddma.c