| /* |
| * 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| * it's no longer valid.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); |
| } |
| |
| if (!qset->remove) |
| 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. |
| * |
| * If the qset was to be reset, do so and reinsert it into the |
| * ASL if it has pending transfers. |
| */ |
| spin_lock_irq(&whc->lock); |
| |
| list_for_each_entry_safe(qset, t, &whc->async_removed_list, list_node) { |
| qset_remove_complete(whc, qset); |
| if (qset->reset) { |
| qset_reset(whc, qset); |
| if (!list_empty(&qset->stds)) { |
| asl_qset_insert_begin(whc, qset); |
| queue_work(whc->workqueue, &whc->async_work); |
| } |
| } |
| } |
| |
| spin_unlock_irq(&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); |
| |
| 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) |
| asl_qset_insert_begin(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->async_work); |
| |
| return err; |
| } |
| |
| /** |
| * 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); |
| } |
| } |