wusb: WHCI host controller driver

A driver for Wireless USB host controllers that comply with the
Wireless Host Controller Interface (HCI) specification as published by
Intel.

The latest publically available version of the specification (0.95) is
supported (except for isochronous transfers).

Build fixes by Randy Dunlap <rdunlap@xenotime.net>

Signed-off-by: David Vrabel <david.vrabel@csr.com>

1 files changed, 367 insertions, 0 deletions

diff --git a/drivers/usb/host/whci/asl.c b/drivers/usb/host/whci/asl.c
new file mode 100644
index 00000000000..4d7078e5057
--- /dev/null
+++ b/drivers/usb/host/whci/asl.c
@@ -0,0 +1,367 @@
+/*
+ * 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>
+#define D_LOCAL 0
+#include <linux/uwb/debug.h>
+
+#include "../../wusbcore/wusbhc.h"
+
+#include "whcd.h"
+
+#if D_LOCAL >= 4
+static void dump_asl(struct whc *whc, const char *tag)
+{
+	struct device *dev = &whc->umc->dev;
+	struct whc_qset *qset;
+
+	d_printf(4, dev, "ASL %s\n", tag);
+
+	list_for_each_entry(qset, &whc->async_list, list_node) {
+		dump_qset(qset, dev);
+	}
+}
+#else
+static inline void dump_asl(struct whc *whc, const char *tag)
+{
+}
+#endif
+
+
+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");
+}
+
+void asl_update(struct whc *whc, uint32_t wusbcmd)
+{
+	whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
+	wait_event(whc->async_list_wq,
+		   (le_readl(whc->base + WUSBCMD) & WUSBCMD_ASYNC_UPDATED) == 0);
+}
+
+/**
+ * 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);
+
+	dump_asl(whc, "before processing");
+
+	/*
+	 * 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);
+	}
+
+	dump_asl(whc, "after processing");
+
+	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);
+	}
+}