1 /*
2 * Wireless Host Controller (WHC) periodic schedule management.
3 *
4 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version
8 * 2 as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 */
18 #include <linux/kernel.h>
19 #include <linux/gfp.h>
20 #include <linux/dma-mapping.h>
21 #include <linux/uwb/umc.h>
22 #include <linux/usb.h>
23
24 #include "../../wusbcore/wusbhc.h"
25
26 #include "whcd.h"
27
update_pzl_pointers(struct whc * whc,int period,u64 addr)28 static void update_pzl_pointers(struct whc *whc, int period, u64 addr)
29 {
30 switch (period) {
31 case 0:
32 whc_qset_set_link_ptr(&whc->pz_list[0], addr);
33 whc_qset_set_link_ptr(&whc->pz_list[2], addr);
34 whc_qset_set_link_ptr(&whc->pz_list[4], addr);
35 whc_qset_set_link_ptr(&whc->pz_list[6], addr);
36 whc_qset_set_link_ptr(&whc->pz_list[8], addr);
37 whc_qset_set_link_ptr(&whc->pz_list[10], addr);
38 whc_qset_set_link_ptr(&whc->pz_list[12], addr);
39 whc_qset_set_link_ptr(&whc->pz_list[14], addr);
40 break;
41 case 1:
42 whc_qset_set_link_ptr(&whc->pz_list[1], addr);
43 whc_qset_set_link_ptr(&whc->pz_list[5], addr);
44 whc_qset_set_link_ptr(&whc->pz_list[9], addr);
45 whc_qset_set_link_ptr(&whc->pz_list[13], addr);
46 break;
47 case 2:
48 whc_qset_set_link_ptr(&whc->pz_list[3], addr);
49 whc_qset_set_link_ptr(&whc->pz_list[11], addr);
50 break;
51 case 3:
52 whc_qset_set_link_ptr(&whc->pz_list[7], addr);
53 break;
54 case 4:
55 whc_qset_set_link_ptr(&whc->pz_list[15], addr);
56 break;
57 }
58 }
59
60 /*
61 * Return the 'period' to use for this qset. The minimum interval for
62 * the endpoint is used so whatever urbs are submitted the device is
63 * polled often enough.
64 */
qset_get_period(struct whc * whc,struct whc_qset * qset)65 static int qset_get_period(struct whc *whc, struct whc_qset *qset)
66 {
67 uint8_t bInterval = qset->ep->desc.bInterval;
68
69 if (bInterval < 6)
70 bInterval = 6;
71 if (bInterval > 10)
72 bInterval = 10;
73 return bInterval - 6;
74 }
75
qset_insert_in_sw_list(struct whc * whc,struct whc_qset * qset)76 static void qset_insert_in_sw_list(struct whc *whc, struct whc_qset *qset)
77 {
78 int period;
79
80 period = qset_get_period(whc, qset);
81
82 qset_clear(whc, qset);
83 list_move(&qset->list_node, &whc->periodic_list[period]);
84 qset->in_sw_list = true;
85 }
86
pzl_qset_remove(struct whc * whc,struct whc_qset * qset)87 static void pzl_qset_remove(struct whc *whc, struct whc_qset *qset)
88 {
89 list_move(&qset->list_node, &whc->periodic_removed_list);
90 qset->in_hw_list = false;
91 qset->in_sw_list = false;
92 }
93
94 /**
95 * pzl_process_qset - process any recently inactivated or halted qTDs
96 * in a qset.
97 *
98 * After inactive qTDs are removed, new qTDs can be added if the
99 * urb queue still contains URBs.
100 *
101 * Returns the schedule updates required.
102 */
pzl_process_qset(struct whc * whc,struct whc_qset * qset)103 static enum whc_update pzl_process_qset(struct whc *whc, struct whc_qset *qset)
104 {
105 enum whc_update update = 0;
106 uint32_t status = 0;
107
108 while (qset->ntds) {
109 struct whc_qtd *td;
110 int t;
111
112 t = qset->td_start;
113 td = &qset->qtd[qset->td_start];
114 status = le32_to_cpu(td->status);
115
116 /*
117 * Nothing to do with a still active qTD.
118 */
119 if (status & QTD_STS_ACTIVE)
120 break;
121
122 if (status & QTD_STS_HALTED) {
123 /* Ug, an error. */
124 process_halted_qtd(whc, qset, td);
125 /* A halted qTD always triggers an update
126 because the qset was either removed or
127 reactivated. */
128 update |= WHC_UPDATE_UPDATED;
129 goto done;
130 }
131
132 /* Mmm, a completed qTD. */
133 process_inactive_qtd(whc, qset, td);
134 }
135
136 if (!qset->remove)
137 update |= qset_add_qtds(whc, qset);
138
139 done:
140 /*
141 * If there are no qTDs in this qset, remove it from the PZL.
142 */
143 if (qset->remove && qset->ntds == 0) {
144 pzl_qset_remove(whc, qset);
145 update |= WHC_UPDATE_REMOVED;
146 }
147
148 return update;
149 }
150
151 /**
152 * pzl_start - start the periodic schedule
153 * @whc: the WHCI host controller
154 *
155 * The PZL must be valid (e.g., all entries in the list should have
156 * the T bit set).
157 */
pzl_start(struct whc * whc)158 void pzl_start(struct whc *whc)
159 {
160 le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
161
162 whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, WUSBCMD_PERIODIC_EN);
163 whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
164 WUSBSTS_PERIODIC_SCHED, WUSBSTS_PERIODIC_SCHED,
165 1000, "start PZL");
166 }
167
168 /**
169 * pzl_stop - stop the periodic schedule
170 * @whc: the WHCI host controller
171 */
pzl_stop(struct whc * whc)172 void pzl_stop(struct whc *whc)
173 {
174 whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, 0);
175 whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
176 WUSBSTS_PERIODIC_SCHED, 0,
177 1000, "stop PZL");
178 }
179
180 /**
181 * pzl_update - request a PZL update and wait for the hardware to be synced
182 * @whc: the WHCI HC
183 * @wusbcmd: WUSBCMD value to start the update.
184 *
185 * If the WUSB HC is inactive (i.e., the PZL is stopped) then the
186 * update must be skipped as the hardware may not respond to update
187 * requests.
188 */
pzl_update(struct whc * whc,uint32_t wusbcmd)189 void pzl_update(struct whc *whc, uint32_t wusbcmd)
190 {
191 struct wusbhc *wusbhc = &whc->wusbhc;
192 long t;
193
194 mutex_lock(&wusbhc->mutex);
195 if (wusbhc->active) {
196 whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
197 t = wait_event_timeout(
198 whc->periodic_list_wq,
199 (le_readl(whc->base + WUSBCMD) & WUSBCMD_PERIODIC_UPDATED) == 0,
200 msecs_to_jiffies(1000));
201 if (t == 0)
202 whc_hw_error(whc, "PZL update timeout");
203 }
204 mutex_unlock(&wusbhc->mutex);
205 }
206
update_pzl_hw_view(struct whc * whc)207 static void update_pzl_hw_view(struct whc *whc)
208 {
209 struct whc_qset *qset, *t;
210 int period;
211 u64 tmp_qh = 0;
212
213 for (period = 0; period < 5; period++) {
214 list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
215 whc_qset_set_link_ptr(&qset->qh.link, tmp_qh);
216 tmp_qh = qset->qset_dma;
217 qset->in_hw_list = true;
218 }
219 update_pzl_pointers(whc, period, tmp_qh);
220 }
221 }
222
223 /**
224 * scan_periodic_work - scan the PZL for qsets to process.
225 *
226 * Process each qset in the PZL in turn and then signal the WHC that
227 * the PZL has been updated.
228 *
229 * Then start, stop or update the periodic schedule as required.
230 */
scan_periodic_work(struct work_struct * work)231 void scan_periodic_work(struct work_struct *work)
232 {
233 struct whc *whc = container_of(work, struct whc, periodic_work);
234 struct whc_qset *qset, *t;
235 enum whc_update update = 0;
236 int period;
237
238 spin_lock_irq(&whc->lock);
239
240 for (period = 4; period >= 0; period--) {
241 list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
242 if (!qset->in_hw_list)
243 update |= WHC_UPDATE_ADDED;
244 update |= pzl_process_qset(whc, qset);
245 }
246 }
247
248 if (update & (WHC_UPDATE_ADDED | WHC_UPDATE_REMOVED))
249 update_pzl_hw_view(whc);
250
251 spin_unlock_irq(&whc->lock);
252
253 if (update) {
254 uint32_t wusbcmd = WUSBCMD_PERIODIC_UPDATED | WUSBCMD_PERIODIC_SYNCED_DB;
255 if (update & WHC_UPDATE_REMOVED)
256 wusbcmd |= WUSBCMD_PERIODIC_QSET_RM;
257 pzl_update(whc, wusbcmd);
258 }
259
260 /*
261 * Now that the PZL is updated, complete the removal of any
262 * removed qsets.
263 *
264 * If the qset was to be reset, do so and reinsert it into the
265 * PZL if it has pending transfers.
266 */
267 spin_lock_irq(&whc->lock);
268
269 list_for_each_entry_safe(qset, t, &whc->periodic_removed_list, list_node) {
270 qset_remove_complete(whc, qset);
271 if (qset->reset) {
272 qset_reset(whc, qset);
273 if (!list_empty(&qset->stds)) {
274 qset_insert_in_sw_list(whc, qset);
275 queue_work(whc->workqueue, &whc->periodic_work);
276 }
277 }
278 }
279
280 spin_unlock_irq(&whc->lock);
281 }
282
283 /**
284 * pzl_urb_enqueue - queue an URB onto the periodic list (PZL)
285 * @whc: the WHCI host controller
286 * @urb: the URB to enqueue
287 * @mem_flags: flags for any memory allocations
288 *
289 * The qset for the endpoint is obtained and the urb queued on to it.
290 *
291 * Work is scheduled to update the hardware's view of the PZL.
292 */
pzl_urb_enqueue(struct whc * whc,struct urb * urb,gfp_t mem_flags)293 int pzl_urb_enqueue(struct whc *whc, struct urb *urb, gfp_t mem_flags)
294 {
295 struct whc_qset *qset;
296 int err;
297 unsigned long flags;
298
299 spin_lock_irqsave(&whc->lock, flags);
300
301 err = usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
302 if (err < 0) {
303 spin_unlock_irqrestore(&whc->lock, flags);
304 return err;
305 }
306
307 qset = get_qset(whc, urb, GFP_ATOMIC);
308 if (qset == NULL)
309 err = -ENOMEM;
310 else
311 err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
312 if (!err) {
313 if (!qset->in_sw_list && !qset->remove)
314 qset_insert_in_sw_list(whc, qset);
315 } else
316 usb_hcd_unlink_urb_from_ep(&whc->wusbhc.usb_hcd, urb);
317
318 spin_unlock_irqrestore(&whc->lock, flags);
319
320 if (!err)
321 queue_work(whc->workqueue, &whc->periodic_work);
322
323 return err;
324 }
325
326 /**
327 * pzl_urb_dequeue - remove an URB (qset) from the periodic list
328 * @whc: the WHCI host controller
329 * @urb: the URB to dequeue
330 * @status: the current status of the URB
331 *
332 * URBs that do yet have qTDs can simply be removed from the software
333 * queue, otherwise the qset must be removed so the qTDs can be safely
334 * removed.
335 */
pzl_urb_dequeue(struct whc * whc,struct urb * urb,int status)336 int pzl_urb_dequeue(struct whc *whc, struct urb *urb, int status)
337 {
338 struct whc_urb *wurb = urb->hcpriv;
339 struct whc_qset *qset = wurb->qset;
340 struct whc_std *std, *t;
341 bool has_qtd = false;
342 int ret;
343 unsigned long flags;
344
345 spin_lock_irqsave(&whc->lock, flags);
346
347 ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
348 if (ret < 0)
349 goto out;
350
351 list_for_each_entry_safe(std, t, &qset->stds, list_node) {
352 if (std->urb == urb) {
353 if (std->qtd)
354 has_qtd = true;
355 qset_free_std(whc, std);
356 } else
357 std->qtd = NULL; /* so this std is re-added when the qset is */
358 }
359
360 if (has_qtd) {
361 pzl_qset_remove(whc, qset);
362 update_pzl_hw_view(whc);
363 wurb->status = status;
364 wurb->is_async = false;
365 queue_work(whc->workqueue, &wurb->dequeue_work);
366 } else
367 qset_remove_urb(whc, qset, urb, status);
368 out:
369 spin_unlock_irqrestore(&whc->lock, flags);
370
371 return ret;
372 }
373
374 /**
375 * pzl_qset_delete - delete a qset from the PZL
376 */
pzl_qset_delete(struct whc * whc,struct whc_qset * qset)377 void pzl_qset_delete(struct whc *whc, struct whc_qset *qset)
378 {
379 qset->remove = 1;
380 queue_work(whc->workqueue, &whc->periodic_work);
381 qset_delete(whc, qset);
382 }
383
384 /**
385 * pzl_init - initialize the periodic zone list
386 * @whc: the WHCI host controller
387 */
pzl_init(struct whc * whc)388 int pzl_init(struct whc *whc)
389 {
390 int i;
391
392 whc->pz_list = dma_alloc_coherent(&whc->umc->dev, sizeof(u64) * 16,
393 &whc->pz_list_dma, GFP_KERNEL);
394 if (whc->pz_list == NULL)
395 return -ENOMEM;
396
397 /* Set T bit on all elements in PZL. */
398 for (i = 0; i < 16; i++)
399 whc->pz_list[i] = cpu_to_le64(QH_LINK_NTDS(8) | QH_LINK_T);
400
401 le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
402
403 return 0;
404 }
405
406 /**
407 * pzl_clean_up - free PZL resources
408 * @whc: the WHCI host controller
409 *
410 * The PZL is stopped and empty.
411 */
pzl_clean_up(struct whc * whc)412 void pzl_clean_up(struct whc *whc)
413 {
414 if (whc->pz_list)
415 dma_free_coherent(&whc->umc->dev, sizeof(u64) * 16, whc->pz_list,
416 whc->pz_list_dma);
417 }
418