summaryrefslogtreecommitdiff
path: root/drivers/usb/host/whci/asl.c
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/usb/host/whci/asl.c
Initial import
Diffstat (limited to 'drivers/usb/host/whci/asl.c')
-rw-r--r--drivers/usb/host/whci/asl.c389
1 files changed, 389 insertions, 0 deletions
diff --git a/drivers/usb/host/whci/asl.c b/drivers/usb/host/whci/asl.c
new file mode 100644
index 000000000..773249306
--- /dev/null
+++ b/drivers/usb/host/whci/asl.c
@@ -0,0 +1,389 @@
+/*
+ * 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/gfp.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);
+ /* A halted qTD always triggers an update
+ because the qset was either removed or
+ reactivated. */
+ update |= WHC_UPDATE_UPDATED;
+ 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;
+ bool has_qtd = false;
+ 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) {
+ if (std->qtd)
+ has_qtd = true;
+ qset_free_std(whc, std);
+ } else
+ std->qtd = NULL; /* so this std is re-added when the qset is */
+ }
+
+ if (has_qtd) {
+ asl_qset_remove(whc, qset);
+ wurb->status = status;
+ wurb->is_async = true;
+ queue_work(whc->workqueue, &wurb->dequeue_work);
+ } else
+ qset_remove_urb(whc, qset, urb, status);
+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);
+ }
+}