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, 398 insertions, 0 deletions

diff --git a/drivers/usb/host/whci/pzl.c b/drivers/usb/host/whci/pzl.c
new file mode 100644
index 00000000000..8d62df0c330
--- /dev/null
+++ b/drivers/usb/host/whci/pzl.c
@@ -0,0 +1,398 @@
+/*
+ * Wireless Host Controller (WHC) periodic 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_pzl(struct whc *whc, const char *tag)
+{
+	struct device *dev = &whc->umc->dev;
+	struct whc_qset *qset;
+	int period = 0;
+
+	d_printf(4, dev, "PZL %s\n", tag);
+
+	for (period = 0; period < 5; period++) {
+		d_printf(4, dev, "Period %d\n", period);
+		list_for_each_entry(qset, &whc->periodic_list[period], list_node) {
+			dump_qset(qset, dev);
+		}
+	}
+}
+#else
+static inline void dump_pzl(struct whc *whc, const char *tag)
+{
+}
+#endif
+
+static void update_pzl_pointers(struct whc *whc, int period, u64 addr)
+{
+	switch (period) {
+	case 0:
+		whc_qset_set_link_ptr(&whc->pz_list[0], addr);
+		whc_qset_set_link_ptr(&whc->pz_list[2], addr);
+		whc_qset_set_link_ptr(&whc->pz_list[4], addr);
+		whc_qset_set_link_ptr(&whc->pz_list[6], addr);
+		whc_qset_set_link_ptr(&whc->pz_list[8], addr);
+		whc_qset_set_link_ptr(&whc->pz_list[10], addr);
+		whc_qset_set_link_ptr(&whc->pz_list[12], addr);
+		whc_qset_set_link_ptr(&whc->pz_list[14], addr);
+		break;
+	case 1:
+		whc_qset_set_link_ptr(&whc->pz_list[1], addr);
+		whc_qset_set_link_ptr(&whc->pz_list[5], addr);
+		whc_qset_set_link_ptr(&whc->pz_list[9], addr);
+		whc_qset_set_link_ptr(&whc->pz_list[13], addr);
+		break;
+	case 2:
+		whc_qset_set_link_ptr(&whc->pz_list[3], addr);
+		whc_qset_set_link_ptr(&whc->pz_list[11], addr);
+		break;
+	case 3:
+		whc_qset_set_link_ptr(&whc->pz_list[7], addr);
+		break;
+	case 4:
+		whc_qset_set_link_ptr(&whc->pz_list[15], addr);
+		break;
+	}
+}
+
+/*
+ * Return the 'period' to use for this qset.  The minimum interval for
+ * the endpoint is used so whatever urbs are submitted the device is
+ * polled often enough.
+ */
+static int qset_get_period(struct whc *whc, struct whc_qset *qset)
+{
+	uint8_t bInterval = qset->ep->desc.bInterval;
+
+	if (bInterval < 6)
+		bInterval = 6;
+	if (bInterval > 10)
+		bInterval = 10;
+	return bInterval - 6;
+}
+
+static void qset_insert_in_sw_list(struct whc *whc, struct whc_qset *qset)
+{
+	int period;
+
+	period = qset_get_period(whc, qset);
+
+	qset_clear(whc, qset);
+	list_move(&qset->list_node, &whc->periodic_list[period]);
+	qset->in_sw_list = true;
+}
+
+static void pzl_qset_remove(struct whc *whc, struct whc_qset *qset)
+{
+	list_move(&qset->list_node, &whc->periodic_removed_list);
+	qset->in_hw_list = false;
+	qset->in_sw_list = false;
+}
+
+/**
+ * pzl_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 the schedule updates required.
+ */
+static enum whc_update pzl_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:
+	/*
+	 * If there are no qTDs in this qset, remove it from the PZL.
+	 */
+	if (qset->remove && qset->ntds == 0) {
+		pzl_qset_remove(whc, qset);
+		update |= WHC_UPDATE_REMOVED;
+	}
+
+	return update;
+}
+
+/**
+ * pzl_start - start the periodic schedule
+ * @whc: the WHCI host controller
+ *
+ * The PZL must be valid (e.g., all entries in the list should have
+ * the T bit set).
+ */
+void pzl_start(struct whc *whc)
+{
+	le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
+
+	whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, WUSBCMD_PERIODIC_EN);
+	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
+		      WUSBSTS_PERIODIC_SCHED, WUSBSTS_PERIODIC_SCHED,
+		      1000, "start PZL");
+}
+
+/**
+ * pzl_stop - stop the periodic schedule
+ * @whc: the WHCI host controller
+ */
+void pzl_stop(struct whc *whc)
+{
+	whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, 0);
+	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
+		      WUSBSTS_PERIODIC_SCHED, 0,
+		      1000, "stop PZL");
+}
+
+void pzl_update(struct whc *whc, uint32_t wusbcmd)
+{
+	whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
+	wait_event(whc->periodic_list_wq,
+		   (le_readl(whc->base + WUSBCMD) & WUSBCMD_PERIODIC_UPDATED) == 0);
+}
+
+static void update_pzl_hw_view(struct whc *whc)
+{
+	struct whc_qset *qset, *t;
+	int period;
+	u64 tmp_qh = 0;
+
+	for (period = 0; period < 5; period++) {
+		list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
+			whc_qset_set_link_ptr(&qset->qh.link, tmp_qh);
+			tmp_qh = qset->qset_dma;
+			qset->in_hw_list = true;
+		}
+		update_pzl_pointers(whc, period, tmp_qh);
+	}
+}
+
+/**
+ * scan_periodic_work - scan the PZL for qsets to process.
+ *
+ * Process each qset in the PZL in turn and then signal the WHC that
+ * the PZL has been updated.
+ *
+ * Then start, stop or update the periodic schedule as required.
+ */
+void scan_periodic_work(struct work_struct *work)
+{
+	struct whc *whc = container_of(work, struct whc, periodic_work);
+	struct whc_qset *qset, *t;
+	enum whc_update update = 0;
+	int period;
+
+	spin_lock_irq(&whc->lock);
+
+	dump_pzl(whc, "before processing");
+
+	for (period = 4; period >= 0; period--) {
+		list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
+			if (!qset->in_hw_list)
+				update |= WHC_UPDATE_ADDED;
+			update |= pzl_process_qset(whc, qset);
+		}
+	}
+
+	if (update & (WHC_UPDATE_ADDED | WHC_UPDATE_REMOVED))
+		update_pzl_hw_view(whc);
+
+	dump_pzl(whc, "after processing");
+
+	spin_unlock_irq(&whc->lock);
+
+	if (update) {
+		uint32_t wusbcmd = WUSBCMD_PERIODIC_UPDATED | WUSBCMD_PERIODIC_SYNCED_DB;
+		if (update & WHC_UPDATE_REMOVED)
+			wusbcmd |= WUSBCMD_PERIODIC_QSET_RM;
+		pzl_update(whc, wusbcmd);
+	}
+
+	/*
+	 * Now that the PZL is updated, complete the removal of any
+	 * removed qsets.
+	 */
+	spin_lock(&whc->lock);
+
+	list_for_each_entry_safe(qset, t, &whc->periodic_removed_list, list_node) {
+		qset_remove_complete(whc, qset);
+	}
+
+	spin_unlock(&whc->lock);
+}
+
+/**
+ * pzl_urb_enqueue - queue an URB onto the periodic list (PZL)
+ * @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 PZL.
+ */
+int pzl_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)
+			qset_insert_in_sw_list(whc, qset);
+	}
+
+	spin_unlock_irqrestore(&whc->lock, flags);
+
+	if (!err)
+		queue_work(whc->workqueue, &whc->periodic_work);
+
+	return 0;
+}
+
+/**
+ * pzl_urb_dequeue - remove an URB (qset) from the periodic 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 so the qTDs can be safely
+ * removed.
+ */
+int pzl_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 */
+	}
+
+	pzl_qset_remove(whc, qset);
+	wurb->status = status;
+	wurb->is_async = false;
+	queue_work(whc->workqueue, &wurb->dequeue_work);
+
+out:
+	spin_unlock_irqrestore(&whc->lock, flags);
+
+	return ret;
+}
+
+/**
+ * pzl_qset_delete - delete a qset from the PZL
+ */
+void pzl_qset_delete(struct whc *whc, struct whc_qset *qset)
+{
+	qset->remove = 1;
+	queue_work(whc->workqueue, &whc->periodic_work);
+	qset_delete(whc, qset);
+}
+
+
+/**
+ * pzl_init - initialize the periodic zone list
+ * @whc: the WHCI host controller
+ */
+int pzl_init(struct whc *whc)
+{
+	int i;
+
+	whc->pz_list = dma_alloc_coherent(&whc->umc->dev, sizeof(u64) * 16,
+					  &whc->pz_list_dma, GFP_KERNEL);
+	if (whc->pz_list == NULL)
+		return -ENOMEM;
+
+	/* Set T bit on all elements in PZL. */
+	for (i = 0; i < 16; i++)
+		whc->pz_list[i] = cpu_to_le64(QH_LINK_NTDS(8) | QH_LINK_T);
+
+	le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
+
+	return 0;
+}
+
+/**
+ * pzl_clean_up - free PZL resources
+ * @whc: the WHCI host controller
+ *
+ * The PZL is stopped and empty.
+ */
+void pzl_clean_up(struct whc *whc)
+{
+	if (whc->pz_list)
+		dma_free_coherent(&whc->umc->dev,  sizeof(u64) * 16, whc->pz_list,
+				  whc->pz_list_dma);
+}