summaryrefslogtreecommitdiff
path: root/drivers/usb/host/whci/pzl.c
blob: bafac6a885517af0daba28634ed4d1f2a0534abd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
// SPDX-License-Identifier: GPL-2.0
/*
 * Wireless Host Controller (WHC) periodic schedule management.
 *
 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/dma-mapping.h>
#include <linux/uwb/umc.h>
#include <linux/usb.h>

#include "../../wusbcore/wusbhc.h"

#include "whcd.h"

static void update_pzl_pointers(struct whc *whc, int period, u64 addr)
{
	switch (period) {
	case 0:
		whc_qset_set_link_ptr(&whc->pz_list[0], addr);
		whc_qset_set_link_ptr(&whc->pz_list[2], addr);
		whc_qset_set_link_ptr(&whc->pz_list[4], addr);
		whc_qset_set_link_ptr(&whc->pz_list[6], addr);
		whc_qset_set_link_ptr(&whc->pz_list[8], addr);
		whc_qset_set_link_ptr(&whc->pz_list[10], addr);
		whc_qset_set_link_ptr(&whc->pz_list[12], addr);
		whc_qset_set_link_ptr(&whc->pz_list[14], addr);
		break;
	case 1:
		whc_qset_set_link_ptr(&whc->pz_list[1], addr);
		whc_qset_set_link_ptr(&whc->pz_list[5], addr);
		whc_qset_set_link_ptr(&whc->pz_list[9], addr);
		whc_qset_set_link_ptr(&whc->pz_list[13], addr);
		break;
	case 2:
		whc_qset_set_link_ptr(&whc->pz_list[3], addr);
		whc_qset_set_link_ptr(&whc->pz_list[11], addr);
		break;
	case 3:
		whc_qset_set_link_ptr(&whc->pz_list[7], addr);
		break;
	case 4:
		whc_qset_set_link_ptr(&whc->pz_list[15], addr);
		break;
	}
}

/*
 * Return the 'period' to use for this qset.  The minimum interval for
 * the endpoint is used so whatever urbs are submitted the device is
 * polled often enough.
 */
static int qset_get_period(struct whc *whc, struct whc_qset *qset)
{
	uint8_t bInterval = qset->ep->desc.bInterval;

	if (bInterval < 6)
		bInterval = 6;
	if (bInterval > 10)
		bInterval = 10;
	return bInterval - 6;
}

static void qset_insert_in_sw_list(struct whc *whc, struct whc_qset *qset)
{
	int period;

	period = qset_get_period(whc, qset);

	qset_clear(whc, qset);
	list_move(&qset->list_node, &whc->periodic_list[period]);
	qset->in_sw_list = true;
}

static void pzl_qset_remove(struct whc *whc, struct whc_qset *qset)
{
	list_move(&qset->list_node, &whc->periodic_removed_list);
	qset->in_hw_list = false;
	qset->in_sw_list = false;
}

/**
 * pzl_process_qset - process any recently inactivated or halted qTDs
 * in a qset.
 *
 * After inactive qTDs are removed, new qTDs can be added if the
 * urb queue still contains URBs.
 *
 * Returns the schedule updates required.
 */
static enum whc_update pzl_process_qset(struct whc *whc, struct whc_qset *qset)
{
	enum whc_update update = 0;
	uint32_t status = 0;

	while (qset->ntds) {
		struct whc_qtd *td;
		int t;

		t = qset->td_start;
		td = &qset->qtd[qset->td_start];
		status = le32_to_cpu(td->status);

		/*
		 * Nothing to do with a still active qTD.
		 */
		if (status & QTD_STS_ACTIVE)
			break;

		if (status & QTD_STS_HALTED) {
			/* Ug, an error. */
			process_halted_qtd(whc, qset, td);
			/* A halted qTD always triggers an update
			   because the qset was either removed or
			   reactivated. */
			update |= WHC_UPDATE_UPDATED;
			goto done;
		}

		/* Mmm, a completed qTD. */
		process_inactive_qtd(whc, qset, td);
	}

	if (!qset->remove)
		update |= qset_add_qtds(whc, qset);

done:
	/*
	 * If there are no qTDs in this qset, remove it from the PZL.
	 */
	if (qset->remove && qset->ntds == 0) {
		pzl_qset_remove(whc, qset);
		update |= WHC_UPDATE_REMOVED;
	}

	return update;
}

/**
 * pzl_start - start the periodic schedule
 * @whc: the WHCI host controller
 *
 * The PZL must be valid (e.g., all entries in the list should have
 * the T bit set).
 */
void pzl_start(struct whc *whc)
{
	le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);

	whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, WUSBCMD_PERIODIC_EN);
	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
		      WUSBSTS_PERIODIC_SCHED, WUSBSTS_PERIODIC_SCHED,
		      1000, "start PZL");
}

/**
 * pzl_stop - stop the periodic schedule
 * @whc: the WHCI host controller
 */
void pzl_stop(struct whc *whc)
{
	whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, 0);
	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
		      WUSBSTS_PERIODIC_SCHED, 0,
		      1000, "stop PZL");
}

/**
 * pzl_update - request a PZL update and wait for the hardware to be synced
 * @whc: the WHCI HC
 * @wusbcmd: WUSBCMD value to start the update.
 *
 * If the WUSB HC is inactive (i.e., the PZL is stopped) then the
 * update must be skipped as the hardware may not respond to update
 * requests.
 */
void pzl_update(struct whc *whc, uint32_t wusbcmd)
{
	struct wusbhc *wusbhc = &whc->wusbhc;
	long t;

	mutex_lock(&wusbhc->mutex);
	if (wusbhc->active) {
		whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
		t = wait_event_timeout(
			whc->periodic_list_wq,
			(le_readl(whc->base + WUSBCMD) & WUSBCMD_PERIODIC_UPDATED) == 0,
			msecs_to_jiffies(1000));
		if (t == 0)
			whc_hw_error(whc, "PZL update timeout");
	}
	mutex_unlock(&wusbhc->mutex);
}

static void update_pzl_hw_view(struct whc *whc)
{
	struct whc_qset *qset, *t;
	int period;
	u64 tmp_qh = 0;

	for (period = 0; period < 5; period++) {
		list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
			whc_qset_set_link_ptr(&qset->qh.link, tmp_qh);
			tmp_qh = qset->qset_dma;
			qset->in_hw_list = true;
		}
		update_pzl_pointers(whc, period, tmp_qh);
	}
}

/**
 * scan_periodic_work - scan the PZL for qsets to process.
 *
 * Process each qset in the PZL in turn and then signal the WHC that
 * the PZL has been updated.
 *
 * Then start, stop or update the periodic schedule as required.
 */
void scan_periodic_work(struct work_struct *work)
{
	struct whc *whc = container_of(work, struct whc, periodic_work);
	struct whc_qset *qset, *t;
	enum whc_update update = 0;
	int period;

	spin_lock_irq(&whc->lock);

	for (period = 4; period >= 0; period--) {
		list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
			if (!qset->in_hw_list)
				update |= WHC_UPDATE_ADDED;
			update |= pzl_process_qset(whc, qset);
		}
	}

	if (update & (WHC_UPDATE_ADDED | WHC_UPDATE_REMOVED))
		update_pzl_hw_view(whc);

	spin_unlock_irq(&whc->lock);

	if (update) {
		uint32_t wusbcmd = WUSBCMD_PERIODIC_UPDATED | WUSBCMD_PERIODIC_SYNCED_DB;
		if (update & WHC_UPDATE_REMOVED)
			wusbcmd |= WUSBCMD_PERIODIC_QSET_RM;
		pzl_update(whc, wusbcmd);
	}

	/*
	 * Now that the PZL is updated, complete the removal of any
	 * removed qsets.
	 *
	 * If the qset was to be reset, do so and reinsert it into the
	 * PZL if it has pending transfers.
	 */
	spin_lock_irq(&whc->lock);

	list_for_each_entry_safe(qset, t, &whc->periodic_removed_list, list_node) {
		qset_remove_complete(whc, qset);
		if (qset->reset) {
			qset_reset(whc, qset);
			if (!list_empty(&qset->stds)) {
				qset_insert_in_sw_list(whc, qset);
				queue_work(whc->workqueue, &whc->periodic_work);
			}
		}
	}

	spin_unlock_irq(&whc->lock);
}

/**
 * pzl_urb_enqueue - queue an URB onto the periodic list (PZL)
 * @whc: the WHCI host controller
 * @urb: the URB to enqueue
 * @mem_flags: flags for any memory allocations
 *
 * The qset for the endpoint is obtained and the urb queued on to it.
 *
 * Work is scheduled to update the hardware's view of the PZL.
 */
int pzl_urb_enqueue(struct whc *whc, struct urb *urb, gfp_t mem_flags)
{
	struct whc_qset *qset;
	int err;
	unsigned long flags;

	spin_lock_irqsave(&whc->lock, flags);

	err = usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
	if (err < 0) {
		spin_unlock_irqrestore(&whc->lock, flags);
		return err;
	}

	qset = get_qset(whc, urb, GFP_ATOMIC);
	if (qset == NULL)
		err = -ENOMEM;
	else
		err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
	if (!err) {
		if (!qset->in_sw_list && !qset->remove)
			qset_insert_in_sw_list(whc, qset);
	} else
		usb_hcd_unlink_urb_from_ep(&whc->wusbhc.usb_hcd, urb);

	spin_unlock_irqrestore(&whc->lock, flags);

	if (!err)
		queue_work(whc->workqueue, &whc->periodic_work);

	return err;
}

/**
 * pzl_urb_dequeue - remove an URB (qset) from the periodic list
 * @whc: the WHCI host controller
 * @urb: the URB to dequeue
 * @status: the current status of the URB
 *
 * URBs that do yet have qTDs can simply be removed from the software
 * queue, otherwise the qset must be removed so the qTDs can be safely
 * removed.
 */
int pzl_urb_dequeue(struct whc *whc, struct urb *urb, int status)
{
	struct whc_urb *wurb = urb->hcpriv;
	struct whc_qset *qset = wurb->qset;
	struct whc_std *std, *t;
	bool has_qtd = false;
	int ret;
	unsigned long flags;

	spin_lock_irqsave(&whc->lock, flags);

	ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
	if (ret < 0)
		goto out;

	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
		if (std->urb == urb) {
			if (std->qtd)
				has_qtd = true;
			qset_free_std(whc, std);
		} else
			std->qtd = NULL; /* so this std is re-added when the qset is */
	}

	if (has_qtd) {
		pzl_qset_remove(whc, qset);
		update_pzl_hw_view(whc);
		wurb->status = status;
		wurb->is_async = false;
		queue_work(whc->workqueue, &wurb->dequeue_work);
	} else
		qset_remove_urb(whc, qset, urb, status);
out:
	spin_unlock_irqrestore(&whc->lock, flags);

	return ret;
}

/**
 * pzl_qset_delete - delete a qset from the PZL
 */
void pzl_qset_delete(struct whc *whc, struct whc_qset *qset)
{
	qset->remove = 1;
	queue_work(whc->workqueue, &whc->periodic_work);
	qset_delete(whc, qset);
}

/**
 * pzl_init - initialize the periodic zone list
 * @whc: the WHCI host controller
 */
int pzl_init(struct whc *whc)
{
	int i;

	whc->pz_list = dma_alloc_coherent(&whc->umc->dev, sizeof(u64) * 16,
					  &whc->pz_list_dma, GFP_KERNEL);
	if (whc->pz_list == NULL)
		return -ENOMEM;

	/* Set T bit on all elements in PZL. */
	for (i = 0; i < 16; i++)
		whc->pz_list[i] = cpu_to_le64(QH_LINK_NTDS(8) | QH_LINK_T);

	le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);

	return 0;
}

/**
 * pzl_clean_up - free PZL resources
 * @whc: the WHCI host controller
 *
 * The PZL is stopped and empty.
 */
void pzl_clean_up(struct whc *whc)
{
	if (whc->pz_list)
		dma_free_coherent(&whc->umc->dev,  sizeof(u64) * 16, whc->pz_list,
				  whc->pz_list_dma);
}