/*
* 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* it's no longer valid.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;
mutex_lock(&wusbhc->mutex);
if (wusbhc->active) {
whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
wait_event(whc->async_list_wq,
(le_readl(whc->base + WUSBCMD) & WUSBCMD_ASYNC_UPDATED) == 0);
}
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);
}
}
