2 * Wireless Host Controller (WHC) asynchronous schedule management.
4 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
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.
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.
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/>.
18 #include <linux/kernel.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/uwb/umc.h>
21 #include <linux/usb.h>
23 #include "../../wusbcore/wusbhc.h"
27 static void qset_get_next_prev(struct whc *whc, struct whc_qset *qset,
28 struct whc_qset **next, struct whc_qset **prev)
30 struct list_head *n, *p;
32 BUG_ON(list_empty(&whc->async_list));
34 n = qset->list_node.next;
35 if (n == &whc->async_list)
37 p = qset->list_node.prev;
38 if (p == &whc->async_list)
41 *next = container_of(n, struct whc_qset, list_node);
42 *prev = container_of(p, struct whc_qset, list_node);
46 static void asl_qset_insert_begin(struct whc *whc, struct whc_qset *qset)
48 list_move(&qset->list_node, &whc->async_list);
49 qset->in_sw_list = true;
52 static void asl_qset_insert(struct whc *whc, struct whc_qset *qset)
54 struct whc_qset *next, *prev;
56 qset_clear(whc, qset);
59 qset_get_next_prev(whc, qset, &next, &prev);
60 whc_qset_set_link_ptr(&qset->qh.link, next->qset_dma);
61 whc_qset_set_link_ptr(&prev->qh.link, qset->qset_dma);
62 qset->in_hw_list = true;
65 static void asl_qset_remove(struct whc *whc, struct whc_qset *qset)
67 struct whc_qset *prev, *next;
69 qset_get_next_prev(whc, qset, &next, &prev);
71 list_move(&qset->list_node, &whc->async_removed_list);
72 qset->in_sw_list = false;
75 * No more qsets in the ASL? The caller must stop the ASL as
76 * it's no longer valid.
78 if (list_empty(&whc->async_list))
81 /* Remove from ASL. */
82 whc_qset_set_link_ptr(&prev->qh.link, next->qset_dma);
83 qset->in_hw_list = false;
87 * process_qset - process any recently inactivated or halted qTDs in a
90 * After inactive qTDs are removed, new qTDs can be added if the
91 * urb queue still contains URBs.
93 * Returns any additional WUSBCMD bits for the ASL sync command (i.e.,
94 * WUSBCMD_ASYNC_QSET_RM if a halted qset was removed).
96 static uint32_t process_qset(struct whc *whc, struct whc_qset *qset)
98 enum whc_update update = 0;
106 td = &qset->qtd[qset->td_start];
107 status = le32_to_cpu(td->status);
110 * Nothing to do with a still active qTD.
112 if (status & QTD_STS_ACTIVE)
115 if (status & QTD_STS_HALTED) {
117 process_halted_qtd(whc, qset, td);
121 /* Mmm, a completed qTD. */
122 process_inactive_qtd(whc, qset, td);
125 update |= qset_add_qtds(whc, qset);
129 * Remove this qset from the ASL if requested, but only if has
132 if (qset->remove && qset->ntds == 0) {
133 asl_qset_remove(whc, qset);
134 update |= WHC_UPDATE_REMOVED;
139 void asl_start(struct whc *whc)
141 struct whc_qset *qset;
143 qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);
145 le_writeq(qset->qset_dma | QH_LINK_NTDS(8), whc->base + WUSBASYNCLISTADDR);
147 whc_write_wusbcmd(whc, WUSBCMD_ASYNC_EN, WUSBCMD_ASYNC_EN);
148 whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
149 WUSBSTS_ASYNC_SCHED, WUSBSTS_ASYNC_SCHED,
153 void asl_stop(struct whc *whc)
155 whc_write_wusbcmd(whc, WUSBCMD_ASYNC_EN, 0);
156 whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
157 WUSBSTS_ASYNC_SCHED, 0,
162 * asl_update - request an ASL update and wait for the hardware to be synced
164 * @wusbcmd: WUSBCMD value to start the update.
166 * If the WUSB HC is inactive (i.e., the ASL is stopped) then the
167 * update must be skipped as the hardware may not respond to update
170 void asl_update(struct whc *whc, uint32_t wusbcmd)
172 struct wusbhc *wusbhc = &whc->wusbhc;
174 mutex_lock(&wusbhc->mutex);
175 if (wusbhc->active) {
176 whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
177 wait_event(whc->async_list_wq,
178 (le_readl(whc->base + WUSBCMD) & WUSBCMD_ASYNC_UPDATED) == 0);
180 mutex_unlock(&wusbhc->mutex);
184 * scan_async_work - scan the ASL for qsets to process.
186 * Process each qset in the ASL in turn and then signal the WHC that
187 * the ASL has been updated.
189 * Then start, stop or update the asynchronous schedule as required.
191 void scan_async_work(struct work_struct *work)
193 struct whc *whc = container_of(work, struct whc, async_work);
194 struct whc_qset *qset, *t;
195 enum whc_update update = 0;
197 spin_lock_irq(&whc->lock);
200 * Transerve the software list backwards so new qsets can be
201 * safely inserted into the ASL without making it non-circular.
203 list_for_each_entry_safe_reverse(qset, t, &whc->async_list, list_node) {
204 if (!qset->in_hw_list) {
205 asl_qset_insert(whc, qset);
206 update |= WHC_UPDATE_ADDED;
209 update |= process_qset(whc, qset);
212 spin_unlock_irq(&whc->lock);
215 uint32_t wusbcmd = WUSBCMD_ASYNC_UPDATED | WUSBCMD_ASYNC_SYNCED_DB;
216 if (update & WHC_UPDATE_REMOVED)
217 wusbcmd |= WUSBCMD_ASYNC_QSET_RM;
218 asl_update(whc, wusbcmd);
222 * Now that the ASL is updated, complete the removal of any
225 spin_lock(&whc->lock);
227 list_for_each_entry_safe(qset, t, &whc->async_removed_list, list_node) {
228 qset_remove_complete(whc, qset);
231 spin_unlock(&whc->lock);
235 * asl_urb_enqueue - queue an URB onto the asynchronous list (ASL).
236 * @whc: the WHCI host controller
237 * @urb: the URB to enqueue
238 * @mem_flags: flags for any memory allocations
240 * The qset for the endpoint is obtained and the urb queued on to it.
242 * Work is scheduled to update the hardware's view of the ASL.
244 int asl_urb_enqueue(struct whc *whc, struct urb *urb, gfp_t mem_flags)
246 struct whc_qset *qset;
250 spin_lock_irqsave(&whc->lock, flags);
252 qset = get_qset(whc, urb, GFP_ATOMIC);
256 err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
258 usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
259 if (!qset->in_sw_list)
260 asl_qset_insert_begin(whc, qset);
263 spin_unlock_irqrestore(&whc->lock, flags);
266 queue_work(whc->workqueue, &whc->async_work);
272 * asl_urb_dequeue - remove an URB (qset) from the async list.
273 * @whc: the WHCI host controller
274 * @urb: the URB to dequeue
275 * @status: the current status of the URB
277 * URBs that do yet have qTDs can simply be removed from the software
278 * queue, otherwise the qset must be removed from the ASL so the qTDs
281 int asl_urb_dequeue(struct whc *whc, struct urb *urb, int status)
283 struct whc_urb *wurb = urb->hcpriv;
284 struct whc_qset *qset = wurb->qset;
285 struct whc_std *std, *t;
289 spin_lock_irqsave(&whc->lock, flags);
291 ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
295 list_for_each_entry_safe(std, t, &qset->stds, list_node) {
297 qset_free_std(whc, std);
299 std->qtd = NULL; /* so this std is re-added when the qset is */
302 asl_qset_remove(whc, qset);
303 wurb->status = status;
304 wurb->is_async = true;
305 queue_work(whc->workqueue, &wurb->dequeue_work);
308 spin_unlock_irqrestore(&whc->lock, flags);
314 * asl_qset_delete - delete a qset from the ASL
316 void asl_qset_delete(struct whc *whc, struct whc_qset *qset)
319 queue_work(whc->workqueue, &whc->async_work);
320 qset_delete(whc, qset);
324 * asl_init - initialize the asynchronous schedule list
326 * A dummy qset with no qTDs is added to the ASL to simplify removing
327 * qsets (no need to stop the ASL when the last qset is removed).
329 int asl_init(struct whc *whc)
331 struct whc_qset *qset;
333 qset = qset_alloc(whc, GFP_KERNEL);
337 asl_qset_insert_begin(whc, qset);
338 asl_qset_insert(whc, qset);
344 * asl_clean_up - free ASL resources
346 * The ASL is stopped and empty except for the dummy qset.
348 void asl_clean_up(struct whc *whc)
350 struct whc_qset *qset;
352 if (!list_empty(&whc->async_list)) {
353 qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);
354 list_del(&qset->list_node);
355 qset_free(whc, qset);