1/*
2 * hcd_ddma.c - DesignWare HS OTG Controller descriptor DMA 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 Descriptor DMA implementation for Host mode
39 */
40#include <linux/kernel.h>
41#include <linux/module.h>
42#include <linux/spinlock.h>
43#include <linux/interrupt.h>
44#include <linux/dma-mapping.h>
45#include <linux/io.h>
46#include <linux/slab.h>
47#include <linux/usb.h>
48
49#include <linux/usb/hcd.h>
50#include <linux/usb/ch11.h>
51
52#include "core.h"
53#include "hcd.h"
54
55static u16 dwc2_frame_list_idx(u16 frame)
56{
57	return frame & (FRLISTEN_64_SIZE - 1);
58}
59
60static u16 dwc2_desclist_idx_inc(u16 idx, u16 inc, u8 speed)
61{
62	return (idx + inc) &
63		((speed == USB_SPEED_HIGH ? MAX_DMA_DESC_NUM_HS_ISOC :
64		  MAX_DMA_DESC_NUM_GENERIC) - 1);
65}
66
67static u16 dwc2_desclist_idx_dec(u16 idx, u16 inc, u8 speed)
68{
69	return (idx - inc) &
70		((speed == USB_SPEED_HIGH ? MAX_DMA_DESC_NUM_HS_ISOC :
71		  MAX_DMA_DESC_NUM_GENERIC) - 1);
72}
73
74static u16 dwc2_max_desc_num(struct dwc2_qh *qh)
75{
76	return (qh->ep_type == USB_ENDPOINT_XFER_ISOC &&
77		qh->dev_speed == USB_SPEED_HIGH) ?
78		MAX_DMA_DESC_NUM_HS_ISOC : MAX_DMA_DESC_NUM_GENERIC;
79}
80
81static u16 dwc2_frame_incr_val(struct dwc2_qh *qh)
82{
83	return qh->dev_speed == USB_SPEED_HIGH ?
84	       (qh->interval + 8 - 1) / 8 : qh->interval;
85}
86
87static int dwc2_desc_list_alloc(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
88				gfp_t flags)
89{
90	qh->desc_list = dma_alloc_coherent(hsotg->dev,
91				sizeof(struct dwc2_hcd_dma_desc) *
92				dwc2_max_desc_num(qh), &qh->desc_list_dma,
93				flags);
94
95	if (!qh->desc_list)
96		return -ENOMEM;
97
98	memset(qh->desc_list, 0,
99	       sizeof(struct dwc2_hcd_dma_desc) * dwc2_max_desc_num(qh));
100
101	qh->n_bytes = kzalloc(sizeof(u32) * dwc2_max_desc_num(qh), flags);
102	if (!qh->n_bytes) {
103		dma_free_coherent(hsotg->dev, sizeof(struct dwc2_hcd_dma_desc)
104				  * dwc2_max_desc_num(qh), qh->desc_list,
105				  qh->desc_list_dma);
106		qh->desc_list = NULL;
107		return -ENOMEM;
108	}
109
110	return 0;
111}
112
113static void dwc2_desc_list_free(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
114{
115	if (qh->desc_list) {
116		dma_free_coherent(hsotg->dev, sizeof(struct dwc2_hcd_dma_desc)
117				  * dwc2_max_desc_num(qh), qh->desc_list,
118				  qh->desc_list_dma);
119		qh->desc_list = NULL;
120	}
121
122	kfree(qh->n_bytes);
123	qh->n_bytes = NULL;
124}
125
126static int dwc2_frame_list_alloc(struct dwc2_hsotg *hsotg, gfp_t mem_flags)
127{
128	if (hsotg->frame_list)
129		return 0;
130
131	hsotg->frame_list = dma_alloc_coherent(hsotg->dev,
132					       4 * FRLISTEN_64_SIZE,
133					       &hsotg->frame_list_dma,
134					       mem_flags);
135	if (!hsotg->frame_list)
136		return -ENOMEM;
137
138	memset(hsotg->frame_list, 0, 4 * FRLISTEN_64_SIZE);
139	return 0;
140}
141
142static void dwc2_frame_list_free(struct dwc2_hsotg *hsotg)
143{
144	u32 *frame_list;
145	dma_addr_t frame_list_dma;
146	unsigned long flags;
147
148	spin_lock_irqsave(&hsotg->lock, flags);
149
150	if (!hsotg->frame_list) {
151		spin_unlock_irqrestore(&hsotg->lock, flags);
152		return;
153	}
154
155	frame_list = hsotg->frame_list;
156	frame_list_dma = hsotg->frame_list_dma;
157	hsotg->frame_list = NULL;
158
159	spin_unlock_irqrestore(&hsotg->lock, flags);
160
161	dma_free_coherent(hsotg->dev, 4 * FRLISTEN_64_SIZE, frame_list,
162			  frame_list_dma);
163}
164
165static void dwc2_per_sched_enable(struct dwc2_hsotg *hsotg, u32 fr_list_en)
166{
167	u32 hcfg;
168	unsigned long flags;
169
170	spin_lock_irqsave(&hsotg->lock, flags);
171
172	hcfg = readl(hsotg->regs + HCFG);
173	if (hcfg & HCFG_PERSCHEDENA) {
174		/* already enabled */
175		spin_unlock_irqrestore(&hsotg->lock, flags);
176		return;
177	}
178
179	writel(hsotg->frame_list_dma, hsotg->regs + HFLBADDR);
180
181	hcfg &= ~HCFG_FRLISTEN_MASK;
182	hcfg |= fr_list_en | HCFG_PERSCHEDENA;
183	dev_vdbg(hsotg->dev, "Enabling Periodic schedule\n");
184	writel(hcfg, hsotg->regs + HCFG);
185
186	spin_unlock_irqrestore(&hsotg->lock, flags);
187}
188
189static void dwc2_per_sched_disable(struct dwc2_hsotg *hsotg)
190{
191	u32 hcfg;
192	unsigned long flags;
193
194	spin_lock_irqsave(&hsotg->lock, flags);
195
196	hcfg = readl(hsotg->regs + HCFG);
197	if (!(hcfg & HCFG_PERSCHEDENA)) {
198		/* already disabled */
199		spin_unlock_irqrestore(&hsotg->lock, flags);
200		return;
201	}
202
203	hcfg &= ~HCFG_PERSCHEDENA;
204	dev_vdbg(hsotg->dev, "Disabling Periodic schedule\n");
205	writel(hcfg, hsotg->regs + HCFG);
206
207	spin_unlock_irqrestore(&hsotg->lock, flags);
208}
209
210/*
211 * Activates/Deactivates FrameList entries for the channel based on endpoint
212 * servicing period
213 */
214static void dwc2_update_frame_list(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
215				   int enable)
216{
217	struct dwc2_host_chan *chan;
218	u16 i, j, inc;
219
220	if (!hsotg) {
221		pr_err("hsotg = %p\n", hsotg);
222		return;
223	}
224
225	if (!qh->channel) {
226		dev_err(hsotg->dev, "qh->channel = %p\n", qh->channel);
227		return;
228	}
229
230	if (!hsotg->frame_list) {
231		dev_err(hsotg->dev, "hsotg->frame_list = %p\n",
232			hsotg->frame_list);
233		return;
234	}
235
236	chan = qh->channel;
237	inc = dwc2_frame_incr_val(qh);
238	if (qh->ep_type == USB_ENDPOINT_XFER_ISOC)
239		i = dwc2_frame_list_idx(qh->sched_frame);
240	else
241		i = 0;
242
243	j = i;
244	do {
245		if (enable)
246			hsotg->frame_list[j] |= 1 << chan->hc_num;
247		else
248			hsotg->frame_list[j] &= ~(1 << chan->hc_num);
249		j = (j + inc) & (FRLISTEN_64_SIZE - 1);
250	} while (j != i);
251
252	if (!enable)
253		return;
254
255	chan->schinfo = 0;
256	if (chan->speed == USB_SPEED_HIGH && qh->interval) {
257		j = 1;
258		/* TODO - check this */
259		inc = (8 + qh->interval - 1) / qh->interval;
260		for (i = 0; i < inc; i++) {
261			chan->schinfo |= j;
262			j = j << qh->interval;
263		}
264	} else {
265		chan->schinfo = 0xff;
266	}
267}
268
269static void dwc2_release_channel_ddma(struct dwc2_hsotg *hsotg,
270				      struct dwc2_qh *qh)
271{
272	struct dwc2_host_chan *chan = qh->channel;
273
274	if (dwc2_qh_is_non_per(qh)) {
275		if (hsotg->core_params->uframe_sched > 0)
276			hsotg->available_host_channels++;
277		else
278			hsotg->non_periodic_channels--;
279	} else {
280		dwc2_update_frame_list(hsotg, qh, 0);
281	}
282
283	/*
284	 * The condition is added to prevent double cleanup try in case of
285	 * device disconnect. See channel cleanup in dwc2_hcd_disconnect().
286	 */
287	if (chan->qh) {
288		if (!list_empty(&chan->hc_list_entry))
289			list_del(&chan->hc_list_entry);
290		dwc2_hc_cleanup(hsotg, chan);
291		list_add_tail(&chan->hc_list_entry, &hsotg->free_hc_list);
292		chan->qh = NULL;
293	}
294
295	qh->channel = NULL;
296	qh->ntd = 0;
297
298	if (qh->desc_list)
299		memset(qh->desc_list, 0, sizeof(struct dwc2_hcd_dma_desc) *
300		       dwc2_max_desc_num(qh));
301}
302
303/**
304 * dwc2_hcd_qh_init_ddma() - Initializes a QH structure's Descriptor DMA
305 * related members
306 *
307 * @hsotg: The HCD state structure for the DWC OTG controller
308 * @qh:    The QH to init
309 *
310 * Return: 0 if successful, negative error code otherwise
311 *
312 * Allocates memory for the descriptor list. For the first periodic QH,
313 * allocates memory for the FrameList and enables periodic scheduling.
314 */
315int dwc2_hcd_qh_init_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
316			  gfp_t mem_flags)
317{
318	int retval;
319
320	if (qh->do_split) {
321		dev_err(hsotg->dev,
322			"SPLIT Transfers are not supported in Descriptor DMA mode.\n");
323		retval = -EINVAL;
324		goto err0;
325	}
326
327	retval = dwc2_desc_list_alloc(hsotg, qh, mem_flags);
328	if (retval)
329		goto err0;
330
331	if (qh->ep_type == USB_ENDPOINT_XFER_ISOC ||
332	    qh->ep_type == USB_ENDPOINT_XFER_INT) {
333		if (!hsotg->frame_list) {
334			retval = dwc2_frame_list_alloc(hsotg, mem_flags);
335			if (retval)
336				goto err1;
337			/* Enable periodic schedule on first periodic QH */
338			dwc2_per_sched_enable(hsotg, HCFG_FRLISTEN_64);
339		}
340	}
341
342	qh->ntd = 0;
343	return 0;
344
345err1:
346	dwc2_desc_list_free(hsotg, qh);
347err0:
348	return retval;
349}
350
351/**
352 * dwc2_hcd_qh_free_ddma() - Frees a QH structure's Descriptor DMA related
353 * members
354 *
355 * @hsotg: The HCD state structure for the DWC OTG controller
356 * @qh:    The QH to free
357 *
358 * Frees descriptor list memory associated with the QH. If QH is periodic and
359 * the last, frees FrameList memory and disables periodic scheduling.
360 */
361void dwc2_hcd_qh_free_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
362{
363	dwc2_desc_list_free(hsotg, qh);
364
365	/*
366	 * Channel still assigned due to some reasons.
367	 * Seen on Isoc URB dequeue. Channel halted but no subsequent
368	 * ChHalted interrupt to release the channel. Afterwards
369	 * when it comes here from endpoint disable routine
370	 * channel remains assigned.
371	 */
372	if (qh->channel)
373		dwc2_release_channel_ddma(hsotg, qh);
374
375	if ((qh->ep_type == USB_ENDPOINT_XFER_ISOC ||
376	     qh->ep_type == USB_ENDPOINT_XFER_INT) &&
377	    (hsotg->core_params->uframe_sched > 0 ||
378	     !hsotg->periodic_channels) && hsotg->frame_list) {
379		dwc2_per_sched_disable(hsotg);
380		dwc2_frame_list_free(hsotg);
381	}
382}
383
384static u8 dwc2_frame_to_desc_idx(struct dwc2_qh *qh, u16 frame_idx)
385{
386	if (qh->dev_speed == USB_SPEED_HIGH)
387		/* Descriptor set (8 descriptors) index which is 8-aligned */
388		return (frame_idx & ((MAX_DMA_DESC_NUM_HS_ISOC / 8) - 1)) * 8;
389	else
390		return frame_idx & (MAX_DMA_DESC_NUM_GENERIC - 1);
391}
392
393/*
394 * Determine starting frame for Isochronous transfer.
395 * Few frames skipped to prevent race condition with HC.
396 */
397static u16 dwc2_calc_starting_frame(struct dwc2_hsotg *hsotg,
398				    struct dwc2_qh *qh, u16 *skip_frames)
399{
400	u16 frame;
401
402	hsotg->frame_number = dwc2_hcd_get_frame_number(hsotg);
403
404	/* sched_frame is always frame number (not uFrame) both in FS and HS! */
405
406	/*
407	 * skip_frames is used to limit activated descriptors number
408	 * to avoid the situation when HC services the last activated
409	 * descriptor firstly.
410	 * Example for FS:
411	 * Current frame is 1, scheduled frame is 3. Since HC always fetches
412	 * the descriptor corresponding to curr_frame+1, the descriptor
413	 * corresponding to frame 2 will be fetched. If the number of
414	 * descriptors is max=64 (or greather) the list will be fully programmed
415	 * with Active descriptors and it is possible case (rare) that the
416	 * latest descriptor(considering rollback) corresponding to frame 2 will
417	 * be serviced first. HS case is more probable because, in fact, up to
418	 * 11 uframes (16 in the code) may be skipped.
419	 */
420	if (qh->dev_speed == USB_SPEED_HIGH) {
421		/*
422		 * Consider uframe counter also, to start xfer asap. If half of
423		 * the frame elapsed skip 2 frames otherwise just 1 frame.
424		 * Starting descriptor index must be 8-aligned, so if the
425		 * current frame is near to complete the next one is skipped as
426		 * well.
427		 */
428		if (dwc2_micro_frame_num(hsotg->frame_number) >= 5) {
429			*skip_frames = 2 * 8;
430			frame = dwc2_frame_num_inc(hsotg->frame_number,
431						   *skip_frames);
432		} else {
433			*skip_frames = 1 * 8;
434			frame = dwc2_frame_num_inc(hsotg->frame_number,
435						   *skip_frames);
436		}
437
438		frame = dwc2_full_frame_num(frame);
439	} else {
440		/*
441		 * Two frames are skipped for FS - the current and the next.
442		 * But for descriptor programming, 1 frame (descriptor) is
443		 * enough, see example above.
444		 */
445		*skip_frames = 1;
446		frame = dwc2_frame_num_inc(hsotg->frame_number, 2);
447	}
448
449	return frame;
450}
451
452/*
453 * Calculate initial descriptor index for isochronous transfer based on
454 * scheduled frame
455 */
456static u16 dwc2_recalc_initial_desc_idx(struct dwc2_hsotg *hsotg,
457					struct dwc2_qh *qh)
458{
459	u16 frame, fr_idx, fr_idx_tmp, skip_frames;
460
461	/*
462	 * With current ISOC processing algorithm the channel is being released
463	 * when no more QTDs in the list (qh->ntd == 0). Thus this function is
464	 * called only when qh->ntd == 0 and qh->channel == 0.
465	 *
466	 * So qh->channel != NULL branch is not used and just not removed from
467	 * the source file. It is required for another possible approach which
468	 * is, do not disable and release the channel when ISOC session
469	 * completed, just move QH to inactive schedule until new QTD arrives.
470	 * On new QTD, the QH moved back to 'ready' schedule, starting frame and
471	 * therefore starting desc_index are recalculated. In this case channel
472	 * is released only on ep_disable.
473	 */
474
475	/*
476	 * Calculate starting descriptor index. For INTERRUPT endpoint it is
477	 * always 0.
478	 */
479	if (qh->channel) {
480		frame = dwc2_calc_starting_frame(hsotg, qh, &skip_frames);
481		/*
482		 * Calculate initial descriptor index based on FrameList current
483		 * bitmap and servicing period
484		 */
485		fr_idx_tmp = dwc2_frame_list_idx(frame);
486		fr_idx = (FRLISTEN_64_SIZE +
487			  dwc2_frame_list_idx(qh->sched_frame) - fr_idx_tmp)
488			 % dwc2_frame_incr_val(qh);
489		fr_idx = (fr_idx + fr_idx_tmp) % FRLISTEN_64_SIZE;
490	} else {
491		qh->sched_frame = dwc2_calc_starting_frame(hsotg, qh,
492							   &skip_frames);
493		fr_idx = dwc2_frame_list_idx(qh->sched_frame);
494	}
495
496	qh->td_first = qh->td_last = dwc2_frame_to_desc_idx(qh, fr_idx);
497
498	return skip_frames;
499}
500
501#define ISOC_URB_GIVEBACK_ASAP
502
503#define MAX_ISOC_XFER_SIZE_FS	1023
504#define MAX_ISOC_XFER_SIZE_HS	3072
505#define DESCNUM_THRESHOLD	4
506
507static void dwc2_fill_host_isoc_dma_desc(struct dwc2_hsotg *hsotg,
508					 struct dwc2_qtd *qtd,
509					 struct dwc2_qh *qh, u32 max_xfer_size,
510					 u16 idx)
511{
512	struct dwc2_hcd_dma_desc *dma_desc = &qh->desc_list[idx];
513	struct dwc2_hcd_iso_packet_desc *frame_desc;
514
515	memset(dma_desc, 0, sizeof(*dma_desc));
516	frame_desc = &qtd->urb->iso_descs[qtd->isoc_frame_index_last];
517
518	if (frame_desc->length > max_xfer_size)
519		qh->n_bytes[idx] = max_xfer_size;
520	else
521		qh->n_bytes[idx] = frame_desc->length;
522
523	dma_desc->buf = (u32)(qtd->urb->dma + frame_desc->offset);
524	dma_desc->status = qh->n_bytes[idx] << HOST_DMA_ISOC_NBYTES_SHIFT &
525			   HOST_DMA_ISOC_NBYTES_MASK;
526
527#ifdef ISOC_URB_GIVEBACK_ASAP
528	/* Set IOC for each descriptor corresponding to last frame of URB */
529	if (qtd->isoc_frame_index_last == qtd->urb->packet_count)
530		dma_desc->status |= HOST_DMA_IOC;
531#endif
532
533	qh->ntd++;
534	qtd->isoc_frame_index_last++;
535}
536
537static void dwc2_init_isoc_dma_desc(struct dwc2_hsotg *hsotg,
538				    struct dwc2_qh *qh, u16 skip_frames)
539{
540	struct dwc2_qtd *qtd;
541	u32 max_xfer_size;
542	u16 idx, inc, n_desc, ntd_max = 0;
543
544	idx = qh->td_last;
545	inc = qh->interval;
546	n_desc = 0;
547
548	if (qh->interval) {
549		ntd_max = (dwc2_max_desc_num(qh) + qh->interval - 1) /
550				qh->interval;
551		if (skip_frames && !qh->channel)
552			ntd_max -= skip_frames / qh->interval;
553	}
554
555	max_xfer_size = qh->dev_speed == USB_SPEED_HIGH ?
556			MAX_ISOC_XFER_SIZE_HS : MAX_ISOC_XFER_SIZE_FS;
557
558	list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry) {
559		while (qh->ntd < ntd_max && qtd->isoc_frame_index_last <
560						qtd->urb->packet_count) {
561			if (n_desc > 1)
562				qh->desc_list[n_desc - 1].status |= HOST_DMA_A;
563			dwc2_fill_host_isoc_dma_desc(hsotg, qtd, qh,
564						     max_xfer_size, idx);
565			idx = dwc2_desclist_idx_inc(idx, inc, qh->dev_speed);
566			n_desc++;
567		}
568		qtd->in_process = 1;
569	}
570
571	qh->td_last = idx;
572
573#ifdef ISOC_URB_GIVEBACK_ASAP
574	/* Set IOC for last descriptor if descriptor list is full */
575	if (qh->ntd == ntd_max) {
576		idx = dwc2_desclist_idx_dec(qh->td_last, inc, qh->dev_speed);
577		qh->desc_list[idx].status |= HOST_DMA_IOC;
578	}
579#else
580	/*
581	 * Set IOC bit only for one descriptor. Always try to be ahead of HW
582	 * processing, i.e. on IOC generation driver activates next descriptor
583	 * but core continues to process descriptors following the one with IOC
584	 * set.
585	 */
586
587	if (n_desc > DESCNUM_THRESHOLD)
588		/*
589		 * Move IOC "up". Required even if there is only one QTD
590		 * in the list, because QTDs might continue to be queued,
591		 * but during the activation it was only one queued.
592		 * Actually more than one QTD might be in the list if this
593		 * function called from XferCompletion - QTDs was queued during
594		 * HW processing of the previous descriptor chunk.
595		 */
596		idx = dwc2_desclist_idx_dec(idx, inc * ((qh->ntd + 1) / 2),
597					    qh->dev_speed);
598	else
599		/*
600		 * Set the IOC for the latest descriptor if either number of
601		 * descriptors is not greater than threshold or no more new
602		 * descriptors activated
603		 */
604		idx = dwc2_desclist_idx_dec(qh->td_last, inc, qh->dev_speed);
605
606	qh->desc_list[idx].status |= HOST_DMA_IOC;
607#endif
608
609	if (n_desc) {
610		qh->desc_list[n_desc - 1].status |= HOST_DMA_A;
611		if (n_desc > 1)
612			qh->desc_list[0].status |= HOST_DMA_A;
613	}
614}
615
616static void dwc2_fill_host_dma_desc(struct dwc2_hsotg *hsotg,
617				    struct dwc2_host_chan *chan,
618				    struct dwc2_qtd *qtd, struct dwc2_qh *qh,
619				    int n_desc)
620{
621	struct dwc2_hcd_dma_desc *dma_desc = &qh->desc_list[n_desc];
622	int len = chan->xfer_len;
623
624	if (len > MAX_DMA_DESC_SIZE - (chan->max_packet - 1))
625		len = MAX_DMA_DESC_SIZE - (chan->max_packet - 1);
626
627	if (chan->ep_is_in) {
628		int num_packets;
629
630		if (len > 0 && chan->max_packet)
631			num_packets = (len + chan->max_packet - 1)
632					/ chan->max_packet;
633		else
634			/* Need 1 packet for transfer length of 0 */
635			num_packets = 1;
636
637		/* Always program an integral # of packets for IN transfers */
638		len = num_packets * chan->max_packet;
639	}
640
641	dma_desc->status = len << HOST_DMA_NBYTES_SHIFT & HOST_DMA_NBYTES_MASK;
642	qh->n_bytes[n_desc] = len;
643
644	if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL &&
645	    qtd->control_phase == DWC2_CONTROL_SETUP)
646		dma_desc->status |= HOST_DMA_SUP;
647
648	dma_desc->buf = (u32)chan->xfer_dma;
649
650	/*
651	 * Last (or only) descriptor of IN transfer with actual size less
652	 * than MaxPacket
653	 */
654	if (len > chan->xfer_len) {
655		chan->xfer_len = 0;
656	} else {
657		chan->xfer_dma += len;
658		chan->xfer_len -= len;
659	}
660}
661
662static void dwc2_init_non_isoc_dma_desc(struct dwc2_hsotg *hsotg,
663					struct dwc2_qh *qh)
664{
665	struct dwc2_qtd *qtd;
666	struct dwc2_host_chan *chan = qh->channel;
667	int n_desc = 0;
668
669	dev_vdbg(hsotg->dev, "%s(): qh=%p dma=%08lx len=%d\n", __func__, qh,
670		 (unsigned long)chan->xfer_dma, chan->xfer_len);
671
672	/*
673	 * Start with chan->xfer_dma initialized in assign_and_init_hc(), then
674	 * if SG transfer consists of multiple URBs, this pointer is re-assigned
675	 * to the buffer of the currently processed QTD. For non-SG request
676	 * there is always one QTD active.
677	 */
678
679	list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry) {
680		dev_vdbg(hsotg->dev, "qtd=%p\n", qtd);
681
682		if (n_desc) {
683			/* SG request - more than 1 QTD */
684			chan->xfer_dma = qtd->urb->dma +
685					qtd->urb->actual_length;
686			chan->xfer_len = qtd->urb->length -
687					qtd->urb->actual_length;
688			dev_vdbg(hsotg->dev, "buf=%08lx len=%d\n",
689				 (unsigned long)chan->xfer_dma, chan->xfer_len);
690		}
691
692		qtd->n_desc = 0;
693		do {
694			if (n_desc > 1) {
695				qh->desc_list[n_desc - 1].status |= HOST_DMA_A;
696				dev_vdbg(hsotg->dev,
697					 "set A bit in desc %d (%p)\n",
698					 n_desc - 1,
699					 &qh->desc_list[n_desc - 1]);
700			}
701			dwc2_fill_host_dma_desc(hsotg, chan, qtd, qh, n_desc);
702			dev_vdbg(hsotg->dev,
703				 "desc %d (%p) buf=%08x status=%08x\n",
704				 n_desc, &qh->desc_list[n_desc],
705				 qh->desc_list[n_desc].buf,
706				 qh->desc_list[n_desc].status);
707			qtd->n_desc++;
708			n_desc++;
709		} while (chan->xfer_len > 0 &&
710			 n_desc != MAX_DMA_DESC_NUM_GENERIC);
711
712		dev_vdbg(hsotg->dev, "n_desc=%d\n", n_desc);
713		qtd->in_process = 1;
714		if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL)
715			break;
716		if (n_desc == MAX_DMA_DESC_NUM_GENERIC)
717			break;
718	}
719
720	if (n_desc) {
721		qh->desc_list[n_desc - 1].status |=
722				HOST_DMA_IOC | HOST_DMA_EOL | HOST_DMA_A;
723		dev_vdbg(hsotg->dev, "set IOC/EOL/A bits in desc %d (%p)\n",
724			 n_desc - 1, &qh->desc_list[n_desc - 1]);
725		if (n_desc > 1) {
726			qh->desc_list[0].status |= HOST_DMA_A;
727			dev_vdbg(hsotg->dev, "set A bit in desc 0 (%p)\n",
728				 &qh->desc_list[0]);
729		}
730		chan->ntd = n_desc;
731	}
732}
733
734/**
735 * dwc2_hcd_start_xfer_ddma() - Starts a transfer in Descriptor DMA mode
736 *
737 * @hsotg: The HCD state structure for the DWC OTG controller
738 * @qh:    The QH to init
739 *
740 * Return: 0 if successful, negative error code otherwise
741 *
742 * For Control and Bulk endpoints, initializes descriptor list and starts the
743 * transfer. For Interrupt and Isochronous endpoints, initializes descriptor
744 * list then updates FrameList, marking appropriate entries as active.
745 *
746 * For Isochronous endpoints the starting descriptor index is calculated based
747 * on the scheduled frame, but only on the first transfer descriptor within a
748 * session. Then the transfer is started via enabling the channel.
749 *
750 * For Isochronous endpoints the channel is not halted on XferComplete
751 * interrupt so remains assigned to the endpoint(QH) until session is done.
752 */
753void dwc2_hcd_start_xfer_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
754{
755	/* Channel is already assigned */
756	struct dwc2_host_chan *chan = qh->channel;
757	u16 skip_frames = 0;
758
759	switch (chan->ep_type) {
760	case USB_ENDPOINT_XFER_CONTROL:
761	case USB_ENDPOINT_XFER_BULK:
762		dwc2_init_non_isoc_dma_desc(hsotg, qh);
763		dwc2_hc_start_transfer_ddma(hsotg, chan);
764		break;
765	case USB_ENDPOINT_XFER_INT:
766		dwc2_init_non_isoc_dma_desc(hsotg, qh);
767		dwc2_update_frame_list(hsotg, qh, 1);
768		dwc2_hc_start_transfer_ddma(hsotg, chan);
769		break;
770	case USB_ENDPOINT_XFER_ISOC:
771		if (!qh->ntd)
772			skip_frames = dwc2_recalc_initial_desc_idx(hsotg, qh);
773		dwc2_init_isoc_dma_desc(hsotg, qh, skip_frames);
774
775		if (!chan->xfer_started) {
776			dwc2_update_frame_list(hsotg, qh, 1);
777
778			/*
779			 * Always set to max, instead of actual size. Otherwise
780			 * ntd will be changed with channel being enabled. Not
781			 * recommended.
782			 */
783			chan->ntd = dwc2_max_desc_num(qh);
784
785			/* Enable channel only once for ISOC */
786			dwc2_hc_start_transfer_ddma(hsotg, chan);
787		}
788
789		break;
790	default:
791		break;
792	}
793}
794
795#define DWC2_CMPL_DONE		1
796#define DWC2_CMPL_STOP		2
797
798static int dwc2_cmpl_host_isoc_dma_desc(struct dwc2_hsotg *hsotg,
799					struct dwc2_host_chan *chan,
800					struct dwc2_qtd *qtd,
801					struct dwc2_qh *qh, u16 idx)
802{
803	struct dwc2_hcd_dma_desc *dma_desc = &qh->desc_list[idx];
804	struct dwc2_hcd_iso_packet_desc *frame_desc;
805	u16 remain = 0;
806	int rc = 0;
807
808	if (!qtd->urb)
809		return -EINVAL;
810
811	frame_desc = &qtd->urb->iso_descs[qtd->isoc_frame_index_last];
812	dma_desc->buf = (u32)(qtd->urb->dma + frame_desc->offset);
813	if (chan->ep_is_in)
814		remain = (dma_desc->status & HOST_DMA_ISOC_NBYTES_MASK) >>
815			 HOST_DMA_ISOC_NBYTES_SHIFT;
816
817	if ((dma_desc->status & HOST_DMA_STS_MASK) == HOST_DMA_STS_PKTERR) {
818		/*
819		 * XactError, or unable to complete all the transactions
820		 * in the scheduled micro-frame/frame, both indicated by
821		 * HOST_DMA_STS_PKTERR
822		 */
823		qtd->urb->error_count++;
824		frame_desc->actual_length = qh->n_bytes[idx] - remain;
825		frame_desc->status = -EPROTO;
826	} else {
827		/* Success */
828		frame_desc->actual_length = qh->n_bytes[idx] - remain;
829		frame_desc->status = 0;
830	}
831
832	if (++qtd->isoc_frame_index == qtd->urb->packet_count) {
833		/*
834		 * urb->status is not used for isoc transfers here. The
835		 * individual frame_desc status are used instead.
836		 */
837		dwc2_host_complete(hsotg, qtd, 0);
838		dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
839
840		/*
841		 * This check is necessary because urb_dequeue can be called
842		 * from urb complete callback (sound driver for example). All
843		 * pending URBs are dequeued there, so no need for further
844		 * processing.
845		 */
846		if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE)
847			return -1;
848		rc = DWC2_CMPL_DONE;
849	}
850
851	qh->ntd--;
852
853	/* Stop if IOC requested descriptor reached */
854	if (dma_desc->status & HOST_DMA_IOC)
855		rc = DWC2_CMPL_STOP;
856
857	return rc;
858}
859
860static void dwc2_complete_isoc_xfer_ddma(struct dwc2_hsotg *hsotg,
861					 struct dwc2_host_chan *chan,
862					 enum dwc2_halt_status halt_status)
863{
864	struct dwc2_hcd_iso_packet_desc *frame_desc;
865	struct dwc2_qtd *qtd, *qtd_tmp;
866	struct dwc2_qh *qh;
867	u16 idx;
868	int rc;
869
870	qh = chan->qh;
871	idx = qh->td_first;
872
873	if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE) {
874		list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry)
875			qtd->in_process = 0;
876		return;
877	}
878
879	if (halt_status == DWC2_HC_XFER_AHB_ERR ||
880	    halt_status == DWC2_HC_XFER_BABBLE_ERR) {
881		/*
882		 * Channel is halted in these error cases, considered as serious
883		 * issues.
884		 * Complete all URBs marking all frames as failed, irrespective
885		 * whether some of the descriptors (frames) succeeded or not.
886		 * Pass error code to completion routine as well, to update
887		 * urb->status, some of class drivers might use it to stop
888		 * queing transfer requests.
889		 */
890		int err = halt_status == DWC2_HC_XFER_AHB_ERR ?
891			  -EIO : -EOVERFLOW;
892
893		list_for_each_entry_safe(qtd, qtd_tmp, &qh->qtd_list,
894					 qtd_list_entry) {
895			if (qtd->urb) {
896				for (idx = 0; idx < qtd->urb->packet_count;
897				     idx++) {
898					frame_desc = &qtd->urb->iso_descs[idx];
899					frame_desc->status = err;
900				}
901
902				dwc2_host_complete(hsotg, qtd, err);
903			}
904
905			dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
906		}
907
908		return;
909	}
910
911	list_for_each_entry_safe(qtd, qtd_tmp, &qh->qtd_list, qtd_list_entry) {
912		if (!qtd->in_process)
913			break;
914		do {
915			rc = dwc2_cmpl_host_isoc_dma_desc(hsotg, chan, qtd, qh,
916							  idx);
917			if (rc < 0)
918				return;
919			idx = dwc2_desclist_idx_inc(idx, qh->interval,
920						    chan->speed);
921			if (rc == DWC2_CMPL_STOP)
922				goto stop_scan;
923			if (rc == DWC2_CMPL_DONE)
924				break;
925		} while (idx != qh->td_first);
926	}
927
928stop_scan:
929	qh->td_first = idx;
930}
931
932static int dwc2_update_non_isoc_urb_state_ddma(struct dwc2_hsotg *hsotg,
933					struct dwc2_host_chan *chan,
934					struct dwc2_qtd *qtd,
935					struct dwc2_hcd_dma_desc *dma_desc,
936					enum dwc2_halt_status halt_status,
937					u32 n_bytes, int *xfer_done)
938{
939	struct dwc2_hcd_urb *urb = qtd->urb;
940	u16 remain = 0;
941
942	if (chan->ep_is_in)
943		remain = (dma_desc->status & HOST_DMA_NBYTES_MASK) >>
944			 HOST_DMA_NBYTES_SHIFT;
945
946	dev_vdbg(hsotg->dev, "remain=%d dwc2_urb=%p\n", remain, urb);
947
948	if (halt_status == DWC2_HC_XFER_AHB_ERR) {
949		dev_err(hsotg->dev, "EIO\n");
950		urb->status = -EIO;
951		return 1;
952	}
953
954	if ((dma_desc->status & HOST_DMA_STS_MASK) == HOST_DMA_STS_PKTERR) {
955		switch (halt_status) {
956		case DWC2_HC_XFER_STALL:
957			dev_vdbg(hsotg->dev, "Stall\n");
958			urb->status = -EPIPE;
959			break;
960		case DWC2_HC_XFER_BABBLE_ERR:
961			dev_err(hsotg->dev, "Babble\n");
962			urb->status = -EOVERFLOW;
963			break;
964		case DWC2_HC_XFER_XACT_ERR:
965			dev_err(hsotg->dev, "XactErr\n");
966			urb->status = -EPROTO;
967			break;
968		default:
969			dev_err(hsotg->dev,
970				"%s: Unhandled descriptor error status (%d)\n",
971				__func__, halt_status);
972			break;
973		}
974		return 1;
975	}
976
977	if (dma_desc->status & HOST_DMA_A) {
978		dev_vdbg(hsotg->dev,
979			 "Active descriptor encountered on channel %d\n",
980			 chan->hc_num);
981		return 0;
982	}
983
984	if (chan->ep_type == USB_ENDPOINT_XFER_CONTROL) {
985		if (qtd->control_phase == DWC2_CONTROL_DATA) {
986			urb->actual_length += n_bytes - remain;
987			if (remain || urb->actual_length >= urb->length) {
988				/*
989				 * For Control Data stage do not set urb->status
990				 * to 0, to prevent URB callback. Set it when
991				 * Status phase is done. See below.
992				 */
993				*xfer_done = 1;
994			}
995		} else if (qtd->control_phase == DWC2_CONTROL_STATUS) {
996			urb->status = 0;
997			*xfer_done = 1;
998		}
999		/* No handling for SETUP stage */
1000	} else {
1001		/* BULK and INTR */
1002		urb->actual_length += n_bytes - remain;
1003		dev_vdbg(hsotg->dev, "length=%d actual=%d\n", urb->length,
1004			 urb->actual_length);
1005		if (remain || urb->actual_length >= urb->length) {
1006			urb->status = 0;
1007			*xfer_done = 1;
1008		}
1009	}
1010
1011	return 0;
1012}
1013
1014static int dwc2_process_non_isoc_desc(struct dwc2_hsotg *hsotg,
1015				      struct dwc2_host_chan *chan,
1016				      int chnum, struct dwc2_qtd *qtd,
1017				      int desc_num,
1018				      enum dwc2_halt_status halt_status,
1019				      int *xfer_done)
1020{
1021	struct dwc2_qh *qh = chan->qh;
1022	struct dwc2_hcd_urb *urb = qtd->urb;
1023	struct dwc2_hcd_dma_desc *dma_desc;
1024	u32 n_bytes;
1025	int failed;
1026
1027	dev_vdbg(hsotg->dev, "%s()\n", __func__);
1028
1029	if (!urb)
1030		return -EINVAL;
1031
1032	dma_desc = &qh->desc_list[desc_num];
1033	n_bytes = qh->n_bytes[desc_num];
1034	dev_vdbg(hsotg->dev,
1035		 "qtd=%p dwc2_urb=%p desc_num=%d desc=%p n_bytes=%d\n",
1036		 qtd, urb, desc_num, dma_desc, n_bytes);
1037	failed = dwc2_update_non_isoc_urb_state_ddma(hsotg, chan, qtd, dma_desc,
1038						     halt_status, n_bytes,
1039						     xfer_done);
1040	if (failed || (*xfer_done && urb->status != -EINPROGRESS)) {
1041		dwc2_host_complete(hsotg, qtd, urb->status);
1042		dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
1043		dev_vdbg(hsotg->dev, "failed=%1x xfer_done=%1x status=%08x\n",
1044			 failed, *xfer_done, urb->status);
1045		return failed;
1046	}
1047
1048	if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL) {
1049		switch (qtd->control_phase) {
1050		case DWC2_CONTROL_SETUP:
1051			if (urb->length > 0)
1052				qtd->control_phase = DWC2_CONTROL_DATA;
1053			else
1054				qtd->control_phase = DWC2_CONTROL_STATUS;
1055			dev_vdbg(hsotg->dev,
1056				 "  Control setup transaction done\n");
1057			break;
1058		case DWC2_CONTROL_DATA:
1059			if (*xfer_done) {
1060				qtd->control_phase = DWC2_CONTROL_STATUS;
1061				dev_vdbg(hsotg->dev,
1062					 "  Control data transfer done\n");
1063			} else if (desc_num + 1 == qtd->n_desc) {
1064				/*
1065				 * Last descriptor for Control data stage which
1066				 * is not completed yet
1067				 */
1068				dwc2_hcd_save_data_toggle(hsotg, chan, chnum,
1069							  qtd);
1070			}
1071			break;
1072		default:
1073			break;
1074		}
1075	}
1076
1077	return 0;
1078}
1079
1080static void dwc2_complete_non_isoc_xfer_ddma(struct dwc2_hsotg *hsotg,
1081					     struct dwc2_host_chan *chan,
1082					     int chnum,
1083					     enum dwc2_halt_status halt_status)
1084{
1085	struct list_head *qtd_item, *qtd_tmp;
1086	struct dwc2_qh *qh = chan->qh;
1087	struct dwc2_qtd *qtd = NULL;
1088	int xfer_done;
1089	int desc_num = 0;
1090
1091	if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE) {
1092		list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry)
1093			qtd->in_process = 0;
1094		return;
1095	}
1096
1097	list_for_each_safe(qtd_item, qtd_tmp, &qh->qtd_list) {
1098		int i;
1099
1100		qtd = list_entry(qtd_item, struct dwc2_qtd, qtd_list_entry);
1101		xfer_done = 0;
1102
1103		for (i = 0; i < qtd->n_desc; i++) {
1104			if (dwc2_process_non_isoc_desc(hsotg, chan, chnum, qtd,
1105						       desc_num, halt_status,
1106						       &xfer_done)) {
1107				qtd = NULL;
1108				break;
1109			}
1110			desc_num++;
1111		}
1112	}
1113
1114	if (qh->ep_type != USB_ENDPOINT_XFER_CONTROL) {
1115		/*
1116		 * Resetting the data toggle for bulk and interrupt endpoints
1117		 * in case of stall. See handle_hc_stall_intr().
1118		 */
1119		if (halt_status == DWC2_HC_XFER_STALL)
1120			qh->data_toggle = DWC2_HC_PID_DATA0;
1121		else if (qtd)
1122			dwc2_hcd_save_data_toggle(hsotg, chan, chnum, qtd);
1123	}
1124
1125	if (halt_status == DWC2_HC_XFER_COMPLETE) {
1126		if (chan->hcint & HCINTMSK_NYET) {
1127			/*
1128			 * Got a NYET on the last transaction of the transfer.
1129			 * It means that the endpoint should be in the PING
1130			 * state at the beginning of the next transfer.
1131			 */
1132			qh->ping_state = 1;
1133		}
1134	}
1135}
1136
1137/**
1138 * dwc2_hcd_complete_xfer_ddma() - Scans the descriptor list, updates URB's
1139 * status and calls completion routine for the URB if it's done. Called from
1140 * interrupt handlers.
1141 *
1142 * @hsotg:       The HCD state structure for the DWC OTG controller
1143 * @chan:        Host channel the transfer is completed on
1144 * @chnum:       Index of Host channel registers
1145 * @halt_status: Reason the channel is being halted or just XferComplete
1146 *               for isochronous transfers
1147 *
1148 * Releases the channel to be used by other transfers.
1149 * In case of Isochronous endpoint the channel is not halted until the end of
1150 * the session, i.e. QTD list is empty.
1151 * If periodic channel released the FrameList is updated accordingly.
1152 * Calls transaction selection routines to activate pending transfers.
1153 */
1154void dwc2_hcd_complete_xfer_ddma(struct dwc2_hsotg *hsotg,
1155				 struct dwc2_host_chan *chan, int chnum,
1156				 enum dwc2_halt_status halt_status)
1157{
1158	struct dwc2_qh *qh = chan->qh;
1159	int continue_isoc_xfer = 0;
1160	enum dwc2_transaction_type tr_type;
1161
1162	if (chan->ep_type == USB_ENDPOINT_XFER_ISOC) {
1163		dwc2_complete_isoc_xfer_ddma(hsotg, chan, halt_status);
1164
1165		/* Release the channel if halted or session completed */
1166		if (halt_status != DWC2_HC_XFER_COMPLETE ||
1167		    list_empty(&qh->qtd_list)) {
1168			/* Halt the channel if session completed */
1169			if (halt_status == DWC2_HC_XFER_COMPLETE)
1170				dwc2_hc_halt(hsotg, chan, halt_status);
1171			dwc2_release_channel_ddma(hsotg, qh);
1172			dwc2_hcd_qh_unlink(hsotg, qh);
1173		} else {
1174			/* Keep in assigned schedule to continue transfer */
1175			list_move(&qh->qh_list_entry,
1176				  &hsotg->periodic_sched_assigned);
1177			continue_isoc_xfer = 1;
1178		}
1179		/*
1180		 * Todo: Consider the case when period exceeds FrameList size.
1181		 * Frame Rollover interrupt should be used.
1182		 */
1183	} else {
1184		/*
1185		 * Scan descriptor list to complete the URB(s), then release
1186		 * the channel
1187		 */
1188		dwc2_complete_non_isoc_xfer_ddma(hsotg, chan, chnum,
1189						 halt_status);
1190		dwc2_release_channel_ddma(hsotg, qh);
1191		dwc2_hcd_qh_unlink(hsotg, qh);
1192
1193		if (!list_empty(&qh->qtd_list)) {
1194			/*
1195			 * Add back to inactive non-periodic schedule on normal
1196			 * completion
1197			 */
1198			dwc2_hcd_qh_add(hsotg, qh);
1199		}
1200	}
1201
1202	tr_type = dwc2_hcd_select_transactions(hsotg);
1203	if (tr_type != DWC2_TRANSACTION_NONE || continue_isoc_xfer) {
1204		if (continue_isoc_xfer) {
1205			if (tr_type == DWC2_TRANSACTION_NONE)
1206				tr_type = DWC2_TRANSACTION_PERIODIC;
1207			else if (tr_type == DWC2_TRANSACTION_NON_PERIODIC)
1208				tr_type = DWC2_TRANSACTION_ALL;
1209		}
1210		dwc2_hcd_queue_transactions(hsotg, tr_type);
1211	}
1212}
1213