[net-next-2.6.git] / drivers / usb / host / whci / asl.c

/*
 * Wireless Host Controller (WHC) asynchronous 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/dma-mapping.h>
#include <linux/uwb/umc.h>
#include <linux/usb.h>

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

#include "whcd.h"

static void qset_get_next_prev(struct whc *whc, struct whc_qset *qset,
			       struct whc_qset **next, struct whc_qset **prev)
{
	struct list_head *n, *p;

	BUG_ON(list_empty(&whc->async_list));

	n = qset->list_node.next;
	if (n == &whc->async_list)
		n = n->next;
	p = qset->list_node.prev;
	if (p == &whc->async_list)
		p = p->prev;

	*next = container_of(n, struct whc_qset, list_node);
	*prev = container_of(p, struct whc_qset, list_node);

}

static void asl_qset_insert_begin(struct whc *whc, struct whc_qset *qset)
{
	list_move(&qset->list_node, &whc->async_list);
	qset->in_sw_list = true;
}

static void asl_qset_insert(struct whc *whc, struct whc_qset *qset)
{
	struct whc_qset *next, *prev;

	qset_clear(whc, qset);

	/* Link into ASL. */
	qset_get_next_prev(whc, qset, &next, &prev);
	whc_qset_set_link_ptr(&qset->qh.link, next->qset_dma);
	whc_qset_set_link_ptr(&prev->qh.link, qset->qset_dma);
	qset->in_hw_list = true;
}

static void asl_qset_remove(struct whc *whc, struct whc_qset *qset)
{
	struct whc_qset *prev, *next;

	qset_get_next_prev(whc, qset, &next, &prev);

	list_move(&qset->list_node, &whc->async_removed_list);
	qset->in_sw_list = false;

	/*
	 * No more qsets in the ASL?  The caller must stop the ASL as
	 * it's no longer valid.
	 */
	if (list_empty(&whc->async_list))
		return;

	/* Remove from ASL. */
	whc_qset_set_link_ptr(&prev->qh.link, next->qset_dma);
	qset->in_hw_list = false;
}

/**
 * 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 any additional WUSBCMD bits for the ASL sync command (i.e.,
 * WUSBCMD_ASYNC_QSET_RM if a halted qset was removed).
 */
static uint32_t 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);
			goto done;
		}

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

	update |= qset_add_qtds(whc, qset);

done:
	/*
	 * Remove this qset from the ASL if requested, but only if has
	 * no qTDs.
	 */
	if (qset->remove && qset->ntds == 0) {
		asl_qset_remove(whc, qset);
		update |= WHC_UPDATE_REMOVED;
	}
	return update;
}

void asl_start(struct whc *whc)
{
	struct whc_qset *qset;

	qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);

	le_writeq(qset->qset_dma | QH_LINK_NTDS(8), whc->base + WUSBASYNCLISTADDR);

	whc_write_wusbcmd(whc, WUSBCMD_ASYNC_EN, WUSBCMD_ASYNC_EN);
	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
		      WUSBSTS_ASYNC_SCHED, WUSBSTS_ASYNC_SCHED,
		      1000, "start ASL");
}

void asl_stop(struct whc *whc)
{
	whc_write_wusbcmd(whc, WUSBCMD_ASYNC_EN, 0);
	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
		      WUSBSTS_ASYNC_SCHED, 0,
		      1000, "stop ASL");
}

/**
 * asl_update - request an ASL 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 ASL is stopped) then the
 * update must be skipped as the hardware may not respond to update
 * requests.
 */
void asl_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->async_list_wq,
			(le_readl(whc->base + WUSBCMD) & WUSBCMD_ASYNC_UPDATED) == 0,
			msecs_to_jiffies(1000));
		if (t == 0)
			whc_hw_error(whc, "ASL update timeout");
	}
	mutex_unlock(&wusbhc->mutex);
}

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

	spin_lock_irq(&whc->lock);

	/*
	 * Transerve the software list backwards so new qsets can be
	 * safely inserted into the ASL without making it non-circular.
	 */
	list_for_each_entry_safe_reverse(qset, t, &whc->async_list, list_node) {
		if (!qset->in_hw_list) {
			asl_qset_insert(whc, qset);
			update |= WHC_UPDATE_ADDED;
		}

		update |= process_qset(whc, qset);
	}

	spin_unlock_irq(&whc->lock);

	if (update) {
		uint32_t wusbcmd = WUSBCMD_ASYNC_UPDATED | WUSBCMD_ASYNC_SYNCED_DB;
		if (update & WHC_UPDATE_REMOVED)
			wusbcmd |= WUSBCMD_ASYNC_QSET_RM;
		asl_update(whc, wusbcmd);
	}

	/*
	 * Now that the ASL is updated, complete the removal of any
	 * removed qsets.
	 */
	spin_lock(&whc->lock);

	list_for_each_entry_safe(qset, t, &whc->async_removed_list, list_node) {
		qset_remove_complete(whc, qset);
	}

	spin_unlock(&whc->lock);
}

/**
 * asl_urb_enqueue - queue an URB onto the asynchronous list (ASL).
 * @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 ASL.
 */
int asl_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);

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

	spin_unlock_irqrestore(&whc->lock, flags);

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

	return 0;
}

/**
 * asl_urb_dequeue - remove an URB (qset) from the async 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 from the ASL so the qTDs
 * can be removed.
 */
int asl_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;
	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)
			qset_free_std(whc, std);
		else
			std->qtd = NULL; /* so this std is re-added when the qset is */
	}

	asl_qset_remove(whc, qset);
	wurb->status = status;
	wurb->is_async = true;
	queue_work(whc->workqueue, &wurb->dequeue_work);

out:
	spin_unlock_irqrestore(&whc->lock, flags);

	return ret;
}

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

/**
 * asl_init - initialize the asynchronous schedule list
 *
 * A dummy qset with no qTDs is added to the ASL to simplify removing
 * qsets (no need to stop the ASL when the last qset is removed).
 */
int asl_init(struct whc *whc)
{
	struct whc_qset *qset;

	qset = qset_alloc(whc, GFP_KERNEL);
	if (qset == NULL)
		return -ENOMEM;

	asl_qset_insert_begin(whc, qset);
	asl_qset_insert(whc, qset);

	return 0;
}

/**
 * asl_clean_up - free ASL resources
 *
 * The ASL is stopped and empty except for the dummy qset.
 */
void asl_clean_up(struct whc *whc)
{
	struct whc_qset *qset;

	if (!list_empty(&whc->async_list)) {
		qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);
		list_del(&qset->list_node);
		qset_free(whc, qset);
	}
}
Commit	Line	Data
7e6133aa DV	1	/*
	2	* Wireless Host Controller (WHC) asynchronous 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/dma-mapping.h>
	20	#include <linux/uwb/umc.h>
	21	#include <linux/usb.h>
7e6133aa DV	22
	23	#include "../../wusbcore/wusbhc.h"
	24
	25	#include "whcd.h"
	26
7e6133aa DV	27	static void qset_get_next_prev(struct whc whc, struct whc_qset qset,
	28	struct whc_qset next, struct whc_qset prev)
	29	{
	30	struct list_head n, p;
	31
	32	BUG_ON(list_empty(&whc->async_list));
	33
	34	n = qset->list_node.next;
	35	if (n == &whc->async_list)
	36	n = n->next;
	37	p = qset->list_node.prev;
	38	if (p == &whc->async_list)
	39	p = p->prev;
	40
	41	*next = container_of(n, struct whc_qset, list_node);
	42	*prev = container_of(p, struct whc_qset, list_node);
	43
	44	}
	45
	46	static void asl_qset_insert_begin(struct whc whc, struct whc_qset qset)
	47	{
	48	list_move(&qset->list_node, &whc->async_list);
	49	qset->in_sw_list = true;
	50	}
	51
	52	static void asl_qset_insert(struct whc whc, struct whc_qset qset)
	53	{
	54	struct whc_qset next, prev;
	55
	56	qset_clear(whc, qset);
	57
	58	/* Link into ASL. */
	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;
	63	}
	64
	65	static void asl_qset_remove(struct whc whc, struct whc_qset qset)
	66	{
	67	struct whc_qset prev, next;
	68
	69	qset_get_next_prev(whc, qset, &next, &prev);
	70
	71	list_move(&qset->list_node, &whc->async_removed_list);
	72	qset->in_sw_list = false;
	73
	74	/*
	75	* No more qsets in the ASL? The caller must stop the ASL as
	76	* it's no longer valid.
	77	*/
	78	if (list_empty(&whc->async_list))
	79	return;
	80
	81	/* Remove from ASL. */
	82	whc_qset_set_link_ptr(&prev->qh.link, next->qset_dma);
	83	qset->in_hw_list = false;
	84	}
	85
	86	/**
	87	* process_qset - process any recently inactivated or halted qTDs in a
	88	* qset.
	89	*
	90	* After inactive qTDs are removed, new qTDs can be added if the
91	* urb queue still contains URBs.
92	*
93	* Returns any additional WUSBCMD bits for the ASL sync command (i.e.,
94	* WUSBCMD_ASYNC_QSET_RM if a halted qset was removed).
95	*/
96	static uint32_t process_qset(struct whc whc, struct whc_qset qset)
97	{
98	enum whc_update update = 0;
99	uint32_t status = 0;
100
101	while (qset->ntds) {
102	struct whc_qtd *td;
103	int t;
104
105	t = qset->td_start;
106	td = &qset->qtd[qset->td_start];
107	status = le32_to_cpu(td->status);
108
109	/*
110	* Nothing to do with a still active qTD.
111	*/
112	if (status & QTD_STS_ACTIVE)
113	break;
114
115	if (status & QTD_STS_HALTED) {
116	/* Ug, an error. */
117	process_halted_qtd(whc, qset, td);
118	goto done;
119	}
120
121	/* Mmm, a completed qTD. */
122	process_inactive_qtd(whc, qset, td);
123	}
124
125	update \|= qset_add_qtds(whc, qset);
126
127	done:
128	/*
129	* Remove this qset from the ASL if requested, but only if has
130	* no qTDs.
131	*/
132	if (qset->remove && qset->ntds == 0) {
133	asl_qset_remove(whc, qset);
134	update \|= WHC_UPDATE_REMOVED;
135	}
136	return update;
137	}
138
139	void asl_start(struct whc *whc)
140	{
141	struct whc_qset *qset;
142
143	qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);
144
145	le_writeq(qset->qset_dma \| QH_LINK_NTDS(8), whc->base + WUSBASYNCLISTADDR);
146
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,
150	1000, "start ASL");
151	}
152
153	void asl_stop(struct whc *whc)
154	{
155	whc_write_wusbcmd(whc, WUSBCMD_ASYNC_EN, 0);
156	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
157	WUSBSTS_ASYNC_SCHED, 0,
158	1000, "stop ASL");
159	}
160
56968d0c DV	161	/**
	162	* asl_update - request an ASL update and wait for the hardware to be synced
	163	* @whc: the WHCI HC
	164	* @wusbcmd: WUSBCMD value to start the update.
	165	*
	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
	168	* requests.
	169	*/
7e6133aa DV	170	void asl_update(struct whc *whc, uint32_t wusbcmd)
7e6133aa DV	171	{
56968d0c	172	struct wusbhc *wusbhc = &whc->wusbhc;
a5e6ced5	173	long t;
56968d0c DV	174
	175	mutex_lock(&wusbhc->mutex);
	176	if (wusbhc->active) {
	177	whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
a5e6ced5 DV	178	t = wait_event_timeout(
	179	whc->async_list_wq,
	180	(le_readl(whc->base + WUSBCMD) & WUSBCMD_ASYNC_UPDATED) == 0,
	181	msecs_to_jiffies(1000));
	182	if (t == 0)
	183	whc_hw_error(whc, "ASL update timeout");
56968d0c DV	184	}
56968d0c DV	185	mutex_unlock(&wusbhc->mutex);
7e6133aa DV	186	}
	187
	188	/**
	189	* scan_async_work - scan the ASL for qsets to process.
	190	*
	191	* Process each qset in the ASL in turn and then signal the WHC that
	192	* the ASL has been updated.
	193	*
	194	* Then start, stop or update the asynchronous schedule as required.
	195	*/
	196	void scan_async_work(struct work_struct *work)
	197	{
	198	struct whc *whc = container_of(work, struct whc, async_work);
	199	struct whc_qset qset, t;
	200	enum whc_update update = 0;
	201
	202	spin_lock_irq(&whc->lock);
	203
7e6133aa DV	204	/*
	205	* Transerve the software list backwards so new qsets can be
	206	* safely inserted into the ASL without making it non-circular.
	207	*/
	208	list_for_each_entry_safe_reverse(qset, t, &whc->async_list, list_node) {
	209	if (!qset->in_hw_list) {
	210	asl_qset_insert(whc, qset);
	211	update \|= WHC_UPDATE_ADDED;
	212	}
	213
	214	update \|= process_qset(whc, qset);
	215	}
	216
7e6133aa DV	217	spin_unlock_irq(&whc->lock);
	218
	219	if (update) {
	220	uint32_t wusbcmd = WUSBCMD_ASYNC_UPDATED \| WUSBCMD_ASYNC_SYNCED_DB;
	221	if (update & WHC_UPDATE_REMOVED)
	222	wusbcmd \|= WUSBCMD_ASYNC_QSET_RM;
	223	asl_update(whc, wusbcmd);
	224	}
	225
	226	/*
	227	* Now that the ASL is updated, complete the removal of any
	228	* removed qsets.
	229	*/
	230	spin_lock(&whc->lock);
	231
	232	list_for_each_entry_safe(qset, t, &whc->async_removed_list, list_node) {
	233	qset_remove_complete(whc, qset);
	234	}
	235
	236	spin_unlock(&whc->lock);
	237	}
	238
	239	/**
	240	* asl_urb_enqueue - queue an URB onto the asynchronous list (ASL).
	241	* @whc: the WHCI host controller
	242	* @urb: the URB to enqueue
	243	* @mem_flags: flags for any memory allocations
	244	*
	245	* The qset for the endpoint is obtained and the urb queued on to it.
	246	*
	247	* Work is scheduled to update the hardware's view of the ASL.
	248	*/
	249	int asl_urb_enqueue(struct whc whc, struct urb urb, gfp_t mem_flags)
	250	{
	251	struct whc_qset *qset;
	252	int err;
	253	unsigned long flags;
	254
	255	spin_lock_irqsave(&whc->lock, flags);
	256
	257	qset = get_qset(whc, urb, GFP_ATOMIC);
	258	if (qset == NULL)
	259	err = -ENOMEM;
	260	else
	261	err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
	262	if (!err) {
	263	usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
	264	if (!qset->in_sw_list)
	265	asl_qset_insert_begin(whc, qset);
	266	}
	267
	268	spin_unlock_irqrestore(&whc->lock, flags);
	269
	270	if (!err)
	271	queue_work(whc->workqueue, &whc->async_work);
	272
	273	return 0;
	274	}
	275
	276	/**
	277	* asl_urb_dequeue - remove an URB (qset) from the async list.
	278	* @whc: the WHCI host controller
	279	* @urb: the URB to dequeue
	280	* @status: the current status of the URB
281	*
282	* URBs that do yet have qTDs can simply be removed from the software
283	* queue, otherwise the qset must be removed from the ASL so the qTDs
284	* can be removed.
285	*/
286	int asl_urb_dequeue(struct whc whc, struct urb urb, int status)
287	{
288	struct whc_urb *wurb = urb->hcpriv;
289	struct whc_qset *qset = wurb->qset;
290	struct whc_std std, t;
291	int ret;
292	unsigned long flags;
293
294	spin_lock_irqsave(&whc->lock, flags);
295
296	ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
297	if (ret < 0)
298	goto out;
299
300	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
301	if (std->urb == urb)
302	qset_free_std(whc, std);
303	else
304	std->qtd = NULL; /* so this std is re-added when the qset is */
305	}
306
307	asl_qset_remove(whc, qset);
308	wurb->status = status;
309	wurb->is_async = true;
310	queue_work(whc->workqueue, &wurb->dequeue_work);
311
312	out:
313	spin_unlock_irqrestore(&whc->lock, flags);
314
315	return ret;
316	}
317
318	/**
319	* asl_qset_delete - delete a qset from the ASL
320	*/
321	void asl_qset_delete(struct whc whc, struct whc_qset qset)
322	{
323	qset->remove = 1;
324	queue_work(whc->workqueue, &whc->async_work);
325	qset_delete(whc, qset);
326	}
327
328	/**
329	* asl_init - initialize the asynchronous schedule list
330	*
331	* A dummy qset with no qTDs is added to the ASL to simplify removing
332	* qsets (no need to stop the ASL when the last qset is removed).
333	*/
334	int asl_init(struct whc *whc)
335	{
336	struct whc_qset *qset;
337
338	qset = qset_alloc(whc, GFP_KERNEL);
339	if (qset == NULL)
340	return -ENOMEM;
341
342	asl_qset_insert_begin(whc, qset);
343	asl_qset_insert(whc, qset);
344
345	return 0;
346	}
347
348	/**
349	* asl_clean_up - free ASL resources
350	*
351	* The ASL is stopped and empty except for the dummy qset.
352	*/
353	void asl_clean_up(struct whc *whc)
354	{
355	struct whc_qset *qset;
356
357	if (!list_empty(&whc->async_list)) {
358	qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);
359	list_del(&qset->list_node);
360	qset_free(whc, qset);
361	}
362	}