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, 567 insertions, 0 deletions

diff --git a/drivers/usb/host/whci/qset.c b/drivers/usb/host/whci/qset.c
new file mode 100644
index 000000000000..0420037d2e18
--- /dev/null
+++ b/drivers/usb/host/whci/qset.c
@@ -0,0 +1,567 @@
+/*
+ * Wireless Host Controller (WHC) qset 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"
+
+void dump_qset(struct whc_qset *qset, struct device *dev)
+{
+	struct whc_std *std;
+	struct urb *urb = NULL;
+	int i;
+
+	dev_dbg(dev, "qset %08x\n", (u32)qset->qset_dma);
+	dev_dbg(dev, "  -> %08x\n", (u32)qset->qh.link);
+	dev_dbg(dev, "  info: %08x %08x %08x\n",
+		qset->qh.info1, qset->qh.info2,  qset->qh.info3);
+	dev_dbg(dev, "  sts: %04x errs: %d\n", qset->qh.status, qset->qh.err_count);
+	dev_dbg(dev, "  TD: sts: %08x opts: %08x\n",
+		qset->qh.overlay.qtd.status, qset->qh.overlay.qtd.options);
+
+	for (i = 0; i < WHCI_QSET_TD_MAX; i++) {
+		dev_dbg(dev, "  %c%c TD[%d]: sts: %08x opts: %08x ptr: %08x\n",
+			i == qset->td_start ? 'S' : ' ',
+			i == qset->td_end ? 'E' : ' ',
+			i, qset->qtd[i].status, qset->qtd[i].options,
+			(u32)qset->qtd[i].page_list_ptr);
+	}
+	dev_dbg(dev, "  ntds: %d\n", qset->ntds);
+	list_for_each_entry(std, &qset->stds, list_node) {
+		if (urb != std->urb) {
+			urb = std->urb;
+			dev_dbg(dev, "  urb %p transferred: %d bytes\n", urb,
+				urb->actual_length);
+		}
+		if (std->qtd)
+			dev_dbg(dev, "    sTD[%td]: %zu bytes @ %08x\n",
+				std->qtd - &qset->qtd[0],
+				std->len, std->num_pointers ?
+				(u32)(std->pl_virt[0].buf_ptr) : (u32)std->dma_addr);
+		else
+			dev_dbg(dev, "    sTD[-]: %zd bytes @ %08x\n",
+				std->len, std->num_pointers ?
+				(u32)(std->pl_virt[0].buf_ptr) : (u32)std->dma_addr);
+	}
+}
+
+struct whc_qset *qset_alloc(struct whc *whc, gfp_t mem_flags)
+{
+	struct whc_qset *qset;
+	dma_addr_t dma;
+
+	qset = dma_pool_alloc(whc->qset_pool, mem_flags, &dma);
+	if (qset == NULL)
+		return NULL;
+	memset(qset, 0, sizeof(struct whc_qset));
+
+	qset->qset_dma = dma;
+	qset->whc = whc;
+
+	INIT_LIST_HEAD(&qset->list_node);
+	INIT_LIST_HEAD(&qset->stds);
+
+	return qset;
+}
+
+/**
+ * qset_fill_qh - fill the static endpoint state in a qset's QHead
+ * @qset: the qset whose QH needs initializing with static endpoint
+ *        state
+ * @urb:  an urb for a transfer to this endpoint
+ */
+static void qset_fill_qh(struct whc_qset *qset, struct urb *urb)
+{
+	struct usb_device *usb_dev = urb->dev;
+	struct usb_wireless_ep_comp_descriptor *epcd;
+	bool is_out;
+
+	is_out = usb_pipeout(urb->pipe);
+
+	epcd = (struct usb_wireless_ep_comp_descriptor *)qset->ep->extra;
+
+	if (epcd) {
+		qset->max_seq = epcd->bMaxSequence;
+		qset->max_burst = epcd->bMaxBurst;
+	} else {
+		qset->max_seq = 2;
+		qset->max_burst = 1;
+	}
+
+	qset->qh.info1 = cpu_to_le32(
+		QH_INFO1_EP(usb_pipeendpoint(urb->pipe))
+		| (is_out ? QH_INFO1_DIR_OUT : QH_INFO1_DIR_IN)
+		| usb_pipe_to_qh_type(urb->pipe)
+		| QH_INFO1_DEV_INFO_IDX(wusb_port_no_to_idx(usb_dev->portnum))
+		| QH_INFO1_MAX_PKT_LEN(usb_maxpacket(urb->dev, urb->pipe, is_out))
+		);
+	qset->qh.info2 = cpu_to_le32(
+		QH_INFO2_BURST(qset->max_burst)
+		| QH_INFO2_DBP(0)
+		| QH_INFO2_MAX_COUNT(3)
+		| QH_INFO2_MAX_RETRY(3)
+		| QH_INFO2_MAX_SEQ(qset->max_seq - 1)
+		);
+	/* FIXME: where can we obtain these Tx parameters from?  Why
+	 * doesn't the chip know what Tx power to use? It knows the Rx
+	 * strength and can presumably guess the Tx power required
+	 * from that? */
+	qset->qh.info3 = cpu_to_le32(
+		QH_INFO3_TX_RATE_53_3
+		| QH_INFO3_TX_PWR(0) /* 0 == max power */
+		);
+}
+
+/**
+ * qset_clear - clear fields in a qset so it may be reinserted into a
+ * schedule
+ */
+void qset_clear(struct whc *whc, struct whc_qset *qset)
+{
+	qset->td_start = qset->td_end = qset->ntds = 0;
+	qset->remove = 0;
+
+	qset->qh.link = cpu_to_le32(QH_LINK_NTDS(8) | QH_LINK_T);
+	qset->qh.status = cpu_to_le16(QH_STATUS_ICUR(qset->td_start));
+	qset->qh.err_count = 0;
+	qset->qh.cur_window = cpu_to_le32((1 << qset->max_burst) - 1);
+	qset->qh.scratch[0] = 0;
+	qset->qh.scratch[1] = 0;
+	qset->qh.scratch[2] = 0;
+
+	memset(&qset->qh.overlay, 0, sizeof(qset->qh.overlay));
+
+	init_completion(&qset->remove_complete);
+}
+
+/**
+ * get_qset - get the qset for an async endpoint
+ *
+ * A new qset is created if one does not already exist.
+ */
+struct whc_qset *get_qset(struct whc *whc, struct urb *urb,
+				 gfp_t mem_flags)
+{
+	struct whc_qset *qset;
+
+	qset = urb->ep->hcpriv;
+	if (qset == NULL) {
+		qset = qset_alloc(whc, mem_flags);
+		if (qset == NULL)
+			return NULL;
+
+		qset->ep = urb->ep;
+		urb->ep->hcpriv = qset;
+		qset_fill_qh(qset, urb);
+	}
+	return qset;
+}
+
+void qset_remove_complete(struct whc *whc, struct whc_qset *qset)
+{
+	list_del_init(&qset->list_node);
+	complete(&qset->remove_complete);
+}
+
+/**
+ * qset_add_qtds - add qTDs for an URB to a qset
+ *
+ * Returns true if the list (ASL/PZL) must be updated because (for a
+ * WHCI 0.95 controller) an activated qTD was pointed to be iCur.
+ */
+enum whc_update qset_add_qtds(struct whc *whc, struct whc_qset *qset)
+{
+	struct whc_std *std;
+	enum whc_update update = 0;
+
+	list_for_each_entry(std, &qset->stds, list_node) {
+		struct whc_qtd *qtd;
+		uint32_t status;
+
+		if (qset->ntds >= WHCI_QSET_TD_MAX
+		    || (qset->pause_after_urb && std->urb != qset->pause_after_urb))
+			break;
+
+		if (std->qtd)
+			continue; /* already has a qTD */
+
+		qtd = std->qtd = &qset->qtd[qset->td_end];
+
+		/* Fill in setup bytes for control transfers. */
+		if (usb_pipecontrol(std->urb->pipe))
+			memcpy(qtd->setup, std->urb->setup_packet, 8);
+
+		status = QTD_STS_ACTIVE | QTD_STS_LEN(std->len);
+
+		if (whc_std_last(std) && usb_pipeout(std->urb->pipe))
+			status |= QTD_STS_LAST_PKT;
+
+		/*
+		 * For an IN transfer the iAlt field should be set so
+		 * the h/w will automatically advance to the next
+		 * transfer. However, if there are 8 or more TDs
+		 * remaining in this transfer then iAlt cannot be set
+		 * as it could point to somewhere in this transfer.
+		 */
+		if (std->ntds_remaining < WHCI_QSET_TD_MAX) {
+			int ialt;
+			ialt = (qset->td_end + std->ntds_remaining) % WHCI_QSET_TD_MAX;
+			status |= QTD_STS_IALT(ialt);
+		} else if (usb_pipein(std->urb->pipe))
+			qset->pause_after_urb = std->urb;
+
+		if (std->num_pointers)
+			qtd->options = cpu_to_le32(QTD_OPT_IOC);
+		else
+			qtd->options = cpu_to_le32(QTD_OPT_IOC | QTD_OPT_SMALL);
+		qtd->page_list_ptr = cpu_to_le64(std->dma_addr);
+
+		qtd->status = cpu_to_le32(status);
+
+		if (QH_STATUS_TO_ICUR(qset->qh.status) == qset->td_end)
+			update = WHC_UPDATE_UPDATED;
+
+		if (++qset->td_end >= WHCI_QSET_TD_MAX)
+			qset->td_end = 0;
+		qset->ntds++;
+	}
+
+	return update;
+}
+
+/**
+ * qset_remove_qtd - remove the first qTD from a qset.
+ *
+ * The qTD might be still active (if it's part of a IN URB that
+ * resulted in a short read) so ensure it's deactivated.
+ */
+static void qset_remove_qtd(struct whc *whc, struct whc_qset *qset)
+{
+	qset->qtd[qset->td_start].status = 0;
+
+	if (++qset->td_start >= WHCI_QSET_TD_MAX)
+		qset->td_start = 0;
+	qset->ntds--;
+}
+
+/**
+ * qset_free_std - remove an sTD and free it.
+ * @whc: the WHCI host controller
+ * @std: the sTD to remove and free.
+ */
+void qset_free_std(struct whc *whc, struct whc_std *std)
+{
+	list_del(&std->list_node);
+	if (std->num_pointers) {
+		dma_unmap_single(whc->wusbhc.dev, std->dma_addr,
+				 std->num_pointers * sizeof(struct whc_page_list_entry),
+				 DMA_TO_DEVICE);
+		kfree(std->pl_virt);
+	}
+
+	kfree(std);
+}
+
+/**
+ * qset_remove_qtds - remove an URB's qTDs (and sTDs).
+ */
+static void qset_remove_qtds(struct whc *whc, struct whc_qset *qset,
+			     struct urb *urb)
+{
+	struct whc_std *std, *t;
+
+	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
+		if (std->urb != urb)
+			break;
+		if (std->qtd != NULL)
+			qset_remove_qtd(whc, qset);
+		qset_free_std(whc, std);
+	}
+}
+
+/**
+ * qset_free_stds - free any remaining sTDs for an URB.
+ */
+static void qset_free_stds(struct whc_qset *qset, struct urb *urb)
+{
+	struct whc_std *std, *t;
+
+	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
+		if (std->urb == urb)
+			qset_free_std(qset->whc, std);
+	}
+}
+
+static int qset_fill_page_list(struct whc *whc, struct whc_std *std, gfp_t mem_flags)
+{
+	dma_addr_t dma_addr = std->dma_addr;
+	dma_addr_t sp, ep;
+	size_t std_len = std->len;
+	size_t pl_len;
+	int p;
+
+	sp = ALIGN(dma_addr, WHCI_PAGE_SIZE);
+	ep = dma_addr + std_len;
+	std->num_pointers = DIV_ROUND_UP(ep - sp, WHCI_PAGE_SIZE);
+
+	pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
+	std->pl_virt = kmalloc(pl_len, mem_flags);
+	if (std->pl_virt == NULL)
+		return -ENOMEM;
+	std->dma_addr = dma_map_single(whc->wusbhc.dev, std->pl_virt, pl_len, DMA_TO_DEVICE);
+
+	for (p = 0; p < std->num_pointers; p++) {
+		std->pl_virt[p].buf_ptr = cpu_to_le64(dma_addr);
+		dma_addr = ALIGN(dma_addr + WHCI_PAGE_SIZE, WHCI_PAGE_SIZE);
+	}
+
+	return 0;
+}
+
+/**
+ * urb_dequeue_work - executes asl/pzl update and gives back the urb to the system.
+ */
+static void urb_dequeue_work(struct work_struct *work)
+{
+	struct whc_urb *wurb = container_of(work, struct whc_urb, dequeue_work);
+	struct whc_qset *qset = wurb->qset;
+	struct whc *whc = qset->whc;
+	unsigned long flags;
+
+	if (wurb->is_async == true)
+		asl_update(whc, WUSBCMD_ASYNC_UPDATED
+			   | WUSBCMD_ASYNC_SYNCED_DB
+			   | WUSBCMD_ASYNC_QSET_RM);
+	else
+		pzl_update(whc, WUSBCMD_PERIODIC_UPDATED
+			   | WUSBCMD_PERIODIC_SYNCED_DB
+			   | WUSBCMD_PERIODIC_QSET_RM);
+
+	spin_lock_irqsave(&whc->lock, flags);
+	qset_remove_urb(whc, qset, wurb->urb, wurb->status);
+	spin_unlock_irqrestore(&whc->lock, flags);
+}
+
+/**
+ * qset_add_urb - add an urb to the qset's queue.
+ *
+ * The URB is chopped into sTDs, one for each qTD that will required.
+ * At least one qTD (and sTD) is required even if the transfer has no
+ * data (e.g., for some control transfers).
+ */
+int qset_add_urb(struct whc *whc, struct whc_qset *qset, struct urb *urb,
+	gfp_t mem_flags)
+{
+	struct whc_urb *wurb;
+	int remaining = urb->transfer_buffer_length;
+	u64 transfer_dma = urb->transfer_dma;
+	int ntds_remaining;
+
+	ntds_remaining = DIV_ROUND_UP(remaining, QTD_MAX_XFER_SIZE);
+	if (ntds_remaining == 0)
+		ntds_remaining = 1;
+
+	wurb = kzalloc(sizeof(struct whc_urb), mem_flags);
+	if (wurb == NULL)
+		goto err_no_mem;
+	urb->hcpriv = wurb;
+	wurb->qset = qset;
+	wurb->urb = urb;
+	INIT_WORK(&wurb->dequeue_work, urb_dequeue_work);
+
+	while (ntds_remaining) {
+		struct whc_std *std;
+		size_t std_len;
+
+		std = kmalloc(sizeof(struct whc_std), mem_flags);
+		if (std == NULL)
+			goto err_no_mem;
+
+		std_len = remaining;
+		if (std_len > QTD_MAX_XFER_SIZE)
+			std_len = QTD_MAX_XFER_SIZE;
+
+		std->urb = urb;
+		std->dma_addr = transfer_dma;
+		std->len = std_len;
+		std->ntds_remaining = ntds_remaining;
+		std->qtd = NULL;
+
+		INIT_LIST_HEAD(&std->list_node);
+		list_add_tail(&std->list_node, &qset->stds);
+
+		if (std_len > WHCI_PAGE_SIZE) {
+			if (qset_fill_page_list(whc, std, mem_flags) < 0)
+				goto err_no_mem;
+		} else
+			std->num_pointers = 0;
+
+		ntds_remaining--;
+		remaining -= std_len;
+		transfer_dma += std_len;
+	}
+
+	return 0;
+
+err_no_mem:
+	qset_free_stds(qset, urb);
+	return -ENOMEM;
+}
+
+/**
+ * qset_remove_urb - remove an URB from the urb queue.
+ *
+ * The URB is returned to the USB subsystem.
+ */
+void qset_remove_urb(struct whc *whc, struct whc_qset *qset,
+			    struct urb *urb, int status)
+{
+	struct wusbhc *wusbhc = &whc->wusbhc;
+	struct whc_urb *wurb = urb->hcpriv;
+
+	usb_hcd_unlink_urb_from_ep(&wusbhc->usb_hcd, urb);
+	/* Drop the lock as urb->complete() may enqueue another urb. */
+	spin_unlock(&whc->lock);
+	wusbhc_giveback_urb(wusbhc, urb, status);
+	spin_lock(&whc->lock);
+
+	kfree(wurb);
+}
+
+/**
+ * get_urb_status_from_qtd - get the completed urb status from qTD status
+ * @urb:    completed urb
+ * @status: qTD status
+ */
+static int get_urb_status_from_qtd(struct urb *urb, u32 status)
+{
+	if (status & QTD_STS_HALTED) {
+		if (status & QTD_STS_DBE)
+			return usb_pipein(urb->pipe) ? -ENOSR : -ECOMM;
+		else if (status & QTD_STS_BABBLE)
+			return -EOVERFLOW;
+		else if (status & QTD_STS_RCE)
+			return -ETIME;
+		return -EPIPE;
+	}
+	if (usb_pipein(urb->pipe)
+	    && (urb->transfer_flags & URB_SHORT_NOT_OK)
+	    && urb->actual_length < urb->transfer_buffer_length)
+		return -EREMOTEIO;
+	return 0;
+}
+
+/**
+ * process_inactive_qtd - process an inactive (but not halted) qTD.
+ *
+ * Update the urb with the transfer bytes from the qTD, if the urb is
+ * completely transfered or (in the case of an IN only) the LPF is
+ * set, then the transfer is complete and the urb should be returned
+ * to the system.
+ */
+void process_inactive_qtd(struct whc *whc, struct whc_qset *qset,
+				 struct whc_qtd *qtd)
+{
+	struct whc_std *std = list_first_entry(&qset->stds, struct whc_std, list_node);
+	struct urb *urb = std->urb;
+	uint32_t status;
+	bool complete;
+
+	status = le32_to_cpu(qtd->status);
+
+	urb->actual_length += std->len - QTD_STS_TO_LEN(status);
+
+	if (usb_pipein(urb->pipe) && (status & QTD_STS_LAST_PKT))
+		complete = true;
+	else
+		complete = whc_std_last(std);
+
+	qset_remove_qtd(whc, qset);
+	qset_free_std(whc, std);
+
+	/*
+	 * Transfers for this URB are complete?  Then return it to the
+	 * USB subsystem.
+	 */
+	if (complete) {
+		qset_remove_qtds(whc, qset, urb);
+		qset_remove_urb(whc, qset, urb, get_urb_status_from_qtd(urb, status));
+
+		/*
+		 * If iAlt isn't valid then the hardware didn't
+		 * advance iCur. Adjust the start and end pointers to
+		 * match iCur.
+		 */
+		if (!(status & QTD_STS_IALT_VALID))
+			qset->td_start = qset->td_end
+				= QH_STATUS_TO_ICUR(le16_to_cpu(qset->qh.status));
+		qset->pause_after_urb = NULL;
+	}
+}
+
+/**
+ * process_halted_qtd - process a qset with a halted qtd
+ *
+ * Remove all the qTDs for the failed URB and return the failed URB to
+ * the USB subsystem.  Then remove all other qTDs so the qset can be
+ * removed.
+ *
+ * FIXME: this is the point where rate adaptation can be done.  If a
+ * transfer failed because it exceeded the maximum number of retries
+ * then it could be reactivated with a slower rate without having to
+ * remove the qset.
+ */
+void process_halted_qtd(struct whc *whc, struct whc_qset *qset,
+			       struct whc_qtd *qtd)
+{
+	struct whc_std *std = list_first_entry(&qset->stds, struct whc_std, list_node);
+	struct urb *urb = std->urb;
+	int urb_status;
+
+	urb_status = get_urb_status_from_qtd(urb, le32_to_cpu(qtd->status));
+
+	qset_remove_qtds(whc, qset, urb);
+	qset_remove_urb(whc, qset, urb, urb_status);
+
+	list_for_each_entry(std, &qset->stds, list_node) {
+		if (qset->ntds == 0)
+			break;
+		qset_remove_qtd(whc, qset);
+		std->qtd = NULL;
+	}
+
+	qset->remove = 1;
+}
+
+void qset_free(struct whc *whc, struct whc_qset *qset)
+{
+	dma_pool_free(whc->qset_pool, qset, qset->qset_dma);
+}
+
+/**
+ * qset_delete - wait for a qset to be unused, then free it.
+ */
+void qset_delete(struct whc *whc, struct whc_qset *qset)
+{
+	wait_for_completion(&qset->remove_complete);
+	qset_free(whc, qset);
+}