staging: greybus: move es2 to drivers/greybus/

The es2 Greybus host controller has long been stable, so move it out of
drivers/staging/ to drivers/greybus/

Cc: Johan Hovold <johan@kernel.org>
Cc: greybus-dev@lists.linaro.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Alex Elder <elder@kernel.org>
Link: https://lore.kernel.org/r/20190825055429.18547-10-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1465 insertions, 0 deletions

diff --git a/drivers/greybus/es2.c b/drivers/greybus/es2.c
new file mode 100644
index 000000000000..366716f11b1a
--- /dev/null
+++ b/drivers/greybus/es2.c
@@ -0,0 +1,1465 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Greybus "AP" USB driver for "ES2" controller chips
+ *
+ * Copyright 2014-2015 Google Inc.
+ * Copyright 2014-2015 Linaro Ltd.
+ */
+#include <linux/kthread.h>
+#include <linux/sizes.h>
+#include <linux/usb.h>
+#include <linux/kfifo.h>
+#include <linux/debugfs.h>
+#include <linux/list.h>
+#include <linux/greybus.h>
+#include <asm/unaligned.h>
+
+#include "arpc.h"
+#include "greybus_trace.h"
+
+
+/* Default timeout for USB vendor requests. */
+#define ES2_USB_CTRL_TIMEOUT	500
+
+/* Default timeout for ARPC CPort requests */
+#define ES2_ARPC_CPORT_TIMEOUT	500
+
+/* Fixed CPort numbers */
+#define ES2_CPORT_CDSI0		16
+#define ES2_CPORT_CDSI1		17
+
+/* Memory sizes for the buffers sent to/from the ES2 controller */
+#define ES2_GBUF_MSG_SIZE_MAX	2048
+
+/* Memory sizes for the ARPC buffers */
+#define ARPC_OUT_SIZE_MAX	U16_MAX
+#define ARPC_IN_SIZE_MAX	128
+
+static const struct usb_device_id id_table[] = {
+	{ USB_DEVICE(0x18d1, 0x1eaf) },
+	{ },
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+#define APB1_LOG_SIZE		SZ_16K
+
+/*
+ * Number of CPort IN urbs in flight at any point in time.
+ * Adjust if we are having stalls in the USB buffer due to not enough urbs in
+ * flight.
+ */
+#define NUM_CPORT_IN_URB	4
+
+/* Number of CPort OUT urbs in flight at any point in time.
+ * Adjust if we get messages saying we are out of urbs in the system log.
+ */
+#define NUM_CPORT_OUT_URB	8
+
+/*
+ * Number of ARPC in urbs in flight at any point in time.
+ */
+#define NUM_ARPC_IN_URB		2
+
+/*
+ * @endpoint: bulk in endpoint for CPort data
+ * @urb: array of urbs for the CPort in messages
+ * @buffer: array of buffers for the @cport_in_urb urbs
+ */
+struct es2_cport_in {
+	__u8 endpoint;
+	struct urb *urb[NUM_CPORT_IN_URB];
+	u8 *buffer[NUM_CPORT_IN_URB];
+};
+
+/**
+ * es2_ap_dev - ES2 USB Bridge to AP structure
+ * @usb_dev: pointer to the USB device we are.
+ * @usb_intf: pointer to the USB interface we are bound to.
+ * @hd: pointer to our gb_host_device structure
+
+ * @cport_in: endpoint, urbs and buffer for cport in messages
+ * @cport_out_endpoint: endpoint for for cport out messages
+ * @cport_out_urb: array of urbs for the CPort out messages
+ * @cport_out_urb_busy: array of flags to see if the @cport_out_urb is busy or
+ *			not.
+ * @cport_out_urb_cancelled: array of flags indicating whether the
+ *			corresponding @cport_out_urb is being cancelled
+ * @cport_out_urb_lock: locks the @cport_out_urb_busy "list"
+ *
+ * @apb_log_task: task pointer for logging thread
+ * @apb_log_dentry: file system entry for the log file interface
+ * @apb_log_enable_dentry: file system entry for enabling logging
+ * @apb_log_fifo: kernel FIFO to carry logged data
+ * @arpc_urb: array of urbs for the ARPC in messages
+ * @arpc_buffer: array of buffers for the @arpc_urb urbs
+ * @arpc_endpoint_in: bulk in endpoint for APBridgeA RPC
+ * @arpc_id_cycle: gives an unique id to ARPC
+ * @arpc_lock: locks ARPC list
+ * @arpcs: list of in progress ARPCs
+ */
+struct es2_ap_dev {
+	struct usb_device *usb_dev;
+	struct usb_interface *usb_intf;
+	struct gb_host_device *hd;
+
+	struct es2_cport_in cport_in;
+	__u8 cport_out_endpoint;
+	struct urb *cport_out_urb[NUM_CPORT_OUT_URB];
+	bool cport_out_urb_busy[NUM_CPORT_OUT_URB];
+	bool cport_out_urb_cancelled[NUM_CPORT_OUT_URB];
+	spinlock_t cport_out_urb_lock;
+
+	bool cdsi1_in_use;
+
+	struct task_struct *apb_log_task;
+	struct dentry *apb_log_dentry;
+	struct dentry *apb_log_enable_dentry;
+	DECLARE_KFIFO(apb_log_fifo, char, APB1_LOG_SIZE);
+
+	__u8 arpc_endpoint_in;
+	struct urb *arpc_urb[NUM_ARPC_IN_URB];
+	u8 *arpc_buffer[NUM_ARPC_IN_URB];
+
+	int arpc_id_cycle;
+	spinlock_t arpc_lock;
+	struct list_head arpcs;
+};
+
+struct arpc {
+	struct list_head list;
+	struct arpc_request_message *req;
+	struct arpc_response_message *resp;
+	struct completion response_received;
+	bool active;
+};
+
+static inline struct es2_ap_dev *hd_to_es2(struct gb_host_device *hd)
+{
+	return (struct es2_ap_dev *)&hd->hd_priv;
+}
+
+static void cport_out_callback(struct urb *urb);
+static void usb_log_enable(struct es2_ap_dev *es2);
+static void usb_log_disable(struct es2_ap_dev *es2);
+static int arpc_sync(struct es2_ap_dev *es2, u8 type, void *payload,
+		     size_t size, int *result, unsigned int timeout);
+
+static int output_sync(struct es2_ap_dev *es2, void *req, u16 size, u8 cmd)
+{
+	struct usb_device *udev = es2->usb_dev;
+	u8 *data;
+	int retval;
+
+	data = kmemdup(req, size, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	retval = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+				 cmd,
+				 USB_DIR_OUT | USB_TYPE_VENDOR |
+				 USB_RECIP_INTERFACE,
+				 0, 0, data, size, ES2_USB_CTRL_TIMEOUT);
+	if (retval < 0)
+		dev_err(&udev->dev, "%s: return error %d\n", __func__, retval);
+	else
+		retval = 0;
+
+	kfree(data);
+	return retval;
+}
+
+static void ap_urb_complete(struct urb *urb)
+{
+	struct usb_ctrlrequest *dr = urb->context;
+
+	kfree(dr);
+	usb_free_urb(urb);
+}
+
+static int output_async(struct es2_ap_dev *es2, void *req, u16 size, u8 cmd)
+{
+	struct usb_device *udev = es2->usb_dev;
+	struct urb *urb;
+	struct usb_ctrlrequest *dr;
+	u8 *buf;
+	int retval;
+
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+	if (!urb)
+		return -ENOMEM;
+
+	dr = kmalloc(sizeof(*dr) + size, GFP_ATOMIC);
+	if (!dr) {
+		usb_free_urb(urb);
+		return -ENOMEM;
+	}
+
+	buf = (u8 *)dr + sizeof(*dr);
+	memcpy(buf, req, size);
+
+	dr->bRequest = cmd;
+	dr->bRequestType = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE;
+	dr->wValue = 0;
+	dr->wIndex = 0;
+	dr->wLength = cpu_to_le16(size);
+
+	usb_fill_control_urb(urb, udev, usb_sndctrlpipe(udev, 0),
+			     (unsigned char *)dr, buf, size,
+			     ap_urb_complete, dr);
+	retval = usb_submit_urb(urb, GFP_ATOMIC);
+	if (retval) {
+		usb_free_urb(urb);
+		kfree(dr);
+	}
+	return retval;
+}
+
+static int output(struct gb_host_device *hd, void *req, u16 size, u8 cmd,
+		  bool async)
+{
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+
+	if (async)
+		return output_async(es2, req, size, cmd);
+
+	return output_sync(es2, req, size, cmd);
+}
+
+static int es2_cport_in_enable(struct es2_ap_dev *es2,
+			       struct es2_cport_in *cport_in)
+{
+	struct urb *urb;
+	int ret;
+	int i;
+
+	for (i = 0; i < NUM_CPORT_IN_URB; ++i) {
+		urb = cport_in->urb[i];
+
+		ret = usb_submit_urb(urb, GFP_KERNEL);
+		if (ret) {
+			dev_err(&es2->usb_dev->dev,
+				"failed to submit in-urb: %d\n", ret);
+			goto err_kill_urbs;
+		}
+	}
+
+	return 0;
+
+err_kill_urbs:
+	for (--i; i >= 0; --i) {
+		urb = cport_in->urb[i];
+		usb_kill_urb(urb);
+	}
+
+	return ret;
+}
+
+static void es2_cport_in_disable(struct es2_ap_dev *es2,
+				 struct es2_cport_in *cport_in)
+{
+	struct urb *urb;
+	int i;
+
+	for (i = 0; i < NUM_CPORT_IN_URB; ++i) {
+		urb = cport_in->urb[i];
+		usb_kill_urb(urb);
+	}
+}
+
+static int es2_arpc_in_enable(struct es2_ap_dev *es2)
+{
+	struct urb *urb;
+	int ret;
+	int i;
+
+	for (i = 0; i < NUM_ARPC_IN_URB; ++i) {
+		urb = es2->arpc_urb[i];
+
+		ret = usb_submit_urb(urb, GFP_KERNEL);
+		if (ret) {
+			dev_err(&es2->usb_dev->dev,
+				"failed to submit arpc in-urb: %d\n", ret);
+			goto err_kill_urbs;
+		}
+	}
+
+	return 0;
+
+err_kill_urbs:
+	for (--i; i >= 0; --i) {
+		urb = es2->arpc_urb[i];
+		usb_kill_urb(urb);
+	}
+
+	return ret;
+}
+
+static void es2_arpc_in_disable(struct es2_ap_dev *es2)
+{
+	struct urb *urb;
+	int i;
+
+	for (i = 0; i < NUM_ARPC_IN_URB; ++i) {
+		urb = es2->arpc_urb[i];
+		usb_kill_urb(urb);
+	}
+}
+
+static struct urb *next_free_urb(struct es2_ap_dev *es2, gfp_t gfp_mask)
+{
+	struct urb *urb = NULL;
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&es2->cport_out_urb_lock, flags);
+
+	/* Look in our pool of allocated urbs first, as that's the "fastest" */
+	for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
+		if (!es2->cport_out_urb_busy[i] &&
+		    !es2->cport_out_urb_cancelled[i]) {
+			es2->cport_out_urb_busy[i] = true;
+			urb = es2->cport_out_urb[i];
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&es2->cport_out_urb_lock, flags);
+	if (urb)
+		return urb;
+
+	/*
+	 * Crap, pool is empty, complain to the syslog and go allocate one
+	 * dynamically as we have to succeed.
+	 */
+	dev_dbg(&es2->usb_dev->dev,
+		"No free CPort OUT urbs, having to dynamically allocate one!\n");
+	return usb_alloc_urb(0, gfp_mask);
+}
+
+static void free_urb(struct es2_ap_dev *es2, struct urb *urb)
+{
+	unsigned long flags;
+	int i;
+	/*
+	 * See if this was an urb in our pool, if so mark it "free", otherwise
+	 * we need to free it ourselves.
+	 */
+	spin_lock_irqsave(&es2->cport_out_urb_lock, flags);
+	for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
+		if (urb == es2->cport_out_urb[i]) {
+			es2->cport_out_urb_busy[i] = false;
+			urb = NULL;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&es2->cport_out_urb_lock, flags);
+
+	/* If urb is not NULL, then we need to free this urb */
+	usb_free_urb(urb);
+}
+
+/*
+ * We (ab)use the operation-message header pad bytes to transfer the
+ * cport id in order to minimise overhead.
+ */
+static void
+gb_message_cport_pack(struct gb_operation_msg_hdr *header, u16 cport_id)
+{
+	header->pad[0] = cport_id;
+}
+
+/* Clear the pad bytes used for the CPort id */
+static void gb_message_cport_clear(struct gb_operation_msg_hdr *header)
+{
+	header->pad[0] = 0;
+}
+
+/* Extract the CPort id packed into the header, and clear it */
+static u16 gb_message_cport_unpack(struct gb_operation_msg_hdr *header)
+{
+	u16 cport_id = header->pad[0];
+
+	gb_message_cport_clear(header);
+
+	return cport_id;
+}
+
+/*
+ * Returns zero if the message was successfully queued, or a negative errno
+ * otherwise.
+ */
+static int message_send(struct gb_host_device *hd, u16 cport_id,
+			struct gb_message *message, gfp_t gfp_mask)
+{
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	struct usb_device *udev = es2->usb_dev;
+	size_t buffer_size;
+	int retval;
+	struct urb *urb;
+	unsigned long flags;
+
+	/*
+	 * The data actually transferred will include an indication
+	 * of where the data should be sent.  Do one last check of
+	 * the target CPort id before filling it in.
+	 */
+	if (!cport_id_valid(hd, cport_id)) {
+		dev_err(&udev->dev, "invalid cport %u\n", cport_id);
+		return -EINVAL;
+	}
+
+	/* Find a free urb */
+	urb = next_free_urb(es2, gfp_mask);
+	if (!urb)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&es2->cport_out_urb_lock, flags);
+	message->hcpriv = urb;
+	spin_unlock_irqrestore(&es2->cport_out_urb_lock, flags);
+
+	/* Pack the cport id into the message header */
+	gb_message_cport_pack(message->header, cport_id);
+
+	buffer_size = sizeof(*message->header) + message->payload_size;
+
+	usb_fill_bulk_urb(urb, udev,
+			  usb_sndbulkpipe(udev,
+					  es2->cport_out_endpoint),
+			  message->buffer, buffer_size,
+			  cport_out_callback, message);
+	urb->transfer_flags |= URB_ZERO_PACKET;
+
+	trace_gb_message_submit(message);
+
+	retval = usb_submit_urb(urb, gfp_mask);
+	if (retval) {
+		dev_err(&udev->dev, "failed to submit out-urb: %d\n", retval);
+
+		spin_lock_irqsave(&es2->cport_out_urb_lock, flags);
+		message->hcpriv = NULL;
+		spin_unlock_irqrestore(&es2->cport_out_urb_lock, flags);
+
+		free_urb(es2, urb);
+		gb_message_cport_clear(message->header);
+
+		return retval;
+	}
+
+	return 0;
+}
+
+/*
+ * Can not be called in atomic context.
+ */
+static void message_cancel(struct gb_message *message)
+{
+	struct gb_host_device *hd = message->operation->connection->hd;
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	struct urb *urb;
+	int i;
+
+	might_sleep();
+
+	spin_lock_irq(&es2->cport_out_urb_lock);
+	urb = message->hcpriv;
+
+	/* Prevent dynamically allocated urb from being deallocated. */
+	usb_get_urb(urb);
+
+	/* Prevent pre-allocated urb from being reused. */
+	for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
+		if (urb == es2->cport_out_urb[i]) {
+			es2->cport_out_urb_cancelled[i] = true;
+			break;
+		}
+	}
+	spin_unlock_irq(&es2->cport_out_urb_lock);
+
+	usb_kill_urb(urb);
+
+	if (i < NUM_CPORT_OUT_URB) {
+		spin_lock_irq(&es2->cport_out_urb_lock);
+		es2->cport_out_urb_cancelled[i] = false;
+		spin_unlock_irq(&es2->cport_out_urb_lock);
+	}
+
+	usb_free_urb(urb);
+}
+
+static int es2_cport_allocate(struct gb_host_device *hd, int cport_id,
+			      unsigned long flags)
+{
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	struct ida *id_map = &hd->cport_id_map;
+	int ida_start, ida_end;
+
+	switch (cport_id) {
+	case ES2_CPORT_CDSI0:
+	case ES2_CPORT_CDSI1:
+		dev_err(&hd->dev, "cport %d not available\n", cport_id);
+		return -EBUSY;
+	}
+
+	if (flags & GB_CONNECTION_FLAG_OFFLOADED &&
+	    flags & GB_CONNECTION_FLAG_CDSI1) {
+		if (es2->cdsi1_in_use) {
+			dev_err(&hd->dev, "CDSI1 already in use\n");
+			return -EBUSY;
+		}
+
+		es2->cdsi1_in_use = true;
+
+		return ES2_CPORT_CDSI1;
+	}
+
+	if (cport_id < 0) {
+		ida_start = 0;
+		ida_end = hd->num_cports;
+	} else if (cport_id < hd->num_cports) {
+		ida_start = cport_id;
+		ida_end = cport_id + 1;
+	} else {
+		dev_err(&hd->dev, "cport %d not available\n", cport_id);
+		return -EINVAL;
+	}
+
+	return ida_simple_get(id_map, ida_start, ida_end, GFP_KERNEL);
+}
+
+static void es2_cport_release(struct gb_host_device *hd, u16 cport_id)
+{
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+
+	switch (cport_id) {
+	case ES2_CPORT_CDSI1:
+		es2->cdsi1_in_use = false;
+		return;
+	}
+
+	ida_simple_remove(&hd->cport_id_map, cport_id);
+}
+
+static int cport_enable(struct gb_host_device *hd, u16 cport_id,
+			unsigned long flags)
+{
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	struct usb_device *udev = es2->usb_dev;
+	struct gb_apb_request_cport_flags *req;
+	u32 connection_flags;
+	int ret;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	connection_flags = 0;
+	if (flags & GB_CONNECTION_FLAG_CONTROL)
+		connection_flags |= GB_APB_CPORT_FLAG_CONTROL;
+	if (flags & GB_CONNECTION_FLAG_HIGH_PRIO)
+		connection_flags |= GB_APB_CPORT_FLAG_HIGH_PRIO;
+
+	req->flags = cpu_to_le32(connection_flags);
+
+	dev_dbg(&hd->dev, "%s - cport = %u, flags = %02x\n", __func__,
+		cport_id, connection_flags);
+
+	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+			      GB_APB_REQUEST_CPORT_FLAGS,
+			      USB_DIR_OUT | USB_TYPE_VENDOR |
+			      USB_RECIP_INTERFACE, cport_id, 0,
+			      req, sizeof(*req), ES2_USB_CTRL_TIMEOUT);
+	if (ret != sizeof(*req)) {
+		dev_err(&udev->dev, "failed to set cport flags for port %d\n",
+			cport_id);
+		if (ret >= 0)
+			ret = -EIO;
+
+		goto out;
+	}
+
+	ret = 0;
+out:
+	kfree(req);
+
+	return ret;
+}
+
+static int es2_cport_connected(struct gb_host_device *hd, u16 cport_id)
+{
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	struct device *dev = &es2->usb_dev->dev;
+	struct arpc_cport_connected_req req;
+	int ret;
+
+	req.cport_id = cpu_to_le16(cport_id);
+	ret = arpc_sync(es2, ARPC_TYPE_CPORT_CONNECTED, &req, sizeof(req),
+			NULL, ES2_ARPC_CPORT_TIMEOUT);
+	if (ret) {
+		dev_err(dev, "failed to set connected state for cport %u: %d\n",
+			cport_id, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int es2_cport_flush(struct gb_host_device *hd, u16 cport_id)
+{
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	struct device *dev = &es2->usb_dev->dev;
+	struct arpc_cport_flush_req req;
+	int ret;
+
+	req.cport_id = cpu_to_le16(cport_id);
+	ret = arpc_sync(es2, ARPC_TYPE_CPORT_FLUSH, &req, sizeof(req),
+			NULL, ES2_ARPC_CPORT_TIMEOUT);
+	if (ret) {
+		dev_err(dev, "failed to flush cport %u: %d\n", cport_id, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int es2_cport_shutdown(struct gb_host_device *hd, u16 cport_id,
+			      u8 phase, unsigned int timeout)
+{
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	struct device *dev = &es2->usb_dev->dev;
+	struct arpc_cport_shutdown_req req;
+	int result;
+	int ret;
+
+	if (timeout > U16_MAX)
+		return -EINVAL;
+
+	req.cport_id = cpu_to_le16(cport_id);
+	req.timeout = cpu_to_le16(timeout);
+	req.phase = phase;
+	ret = arpc_sync(es2, ARPC_TYPE_CPORT_SHUTDOWN, &req, sizeof(req),
+			&result, ES2_ARPC_CPORT_TIMEOUT + timeout);
+	if (ret) {
+		dev_err(dev, "failed to send shutdown over cport %u: %d (%d)\n",
+			cport_id, ret, result);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int es2_cport_quiesce(struct gb_host_device *hd, u16 cport_id,
+			     size_t peer_space, unsigned int timeout)
+{
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	struct device *dev = &es2->usb_dev->dev;
+	struct arpc_cport_quiesce_req req;
+	int result;
+	int ret;
+
+	if (peer_space > U16_MAX)
+		return -EINVAL;
+
+	if (timeout > U16_MAX)
+		return -EINVAL;
+
+	req.cport_id = cpu_to_le16(cport_id);
+	req.peer_space = cpu_to_le16(peer_space);
+	req.timeout = cpu_to_le16(timeout);
+	ret = arpc_sync(es2, ARPC_TYPE_CPORT_QUIESCE, &req, sizeof(req),
+			&result, ES2_ARPC_CPORT_TIMEOUT + timeout);
+	if (ret) {
+		dev_err(dev, "failed to quiesce cport %u: %d (%d)\n",
+			cport_id, ret, result);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int es2_cport_clear(struct gb_host_device *hd, u16 cport_id)
+{
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	struct device *dev = &es2->usb_dev->dev;
+	struct arpc_cport_clear_req req;
+	int ret;
+
+	req.cport_id = cpu_to_le16(cport_id);
+	ret = arpc_sync(es2, ARPC_TYPE_CPORT_CLEAR, &req, sizeof(req),
+			NULL, ES2_ARPC_CPORT_TIMEOUT);
+	if (ret) {
+		dev_err(dev, "failed to clear cport %u: %d\n", cport_id, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int latency_tag_enable(struct gb_host_device *hd, u16 cport_id)
+{
+	int retval;
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	struct usb_device *udev = es2->usb_dev;
+
+	retval = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+				 GB_APB_REQUEST_LATENCY_TAG_EN,
+				 USB_DIR_OUT | USB_TYPE_VENDOR |
+				 USB_RECIP_INTERFACE, cport_id, 0, NULL,
+				 0, ES2_USB_CTRL_TIMEOUT);
+
+	if (retval < 0)
+		dev_err(&udev->dev, "Cannot enable latency tag for cport %d\n",
+			cport_id);
+	return retval;
+}
+
+static int latency_tag_disable(struct gb_host_device *hd, u16 cport_id)
+{
+	int retval;
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	struct usb_device *udev = es2->usb_dev;
+
+	retval = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+				 GB_APB_REQUEST_LATENCY_TAG_DIS,
+				 USB_DIR_OUT | USB_TYPE_VENDOR |
+				 USB_RECIP_INTERFACE, cport_id, 0, NULL,
+				 0, ES2_USB_CTRL_TIMEOUT);
+
+	if (retval < 0)
+		dev_err(&udev->dev, "Cannot disable latency tag for cport %d\n",
+			cport_id);
+	return retval;
+}
+
+static struct gb_hd_driver es2_driver = {
+	.hd_priv_size			= sizeof(struct es2_ap_dev),
+	.message_send			= message_send,
+	.message_cancel			= message_cancel,
+	.cport_allocate			= es2_cport_allocate,
+	.cport_release			= es2_cport_release,
+	.cport_enable			= cport_enable,
+	.cport_connected		= es2_cport_connected,
+	.cport_flush			= es2_cport_flush,
+	.cport_shutdown			= es2_cport_shutdown,
+	.cport_quiesce			= es2_cport_quiesce,
+	.cport_clear			= es2_cport_clear,
+	.latency_tag_enable		= latency_tag_enable,
+	.latency_tag_disable		= latency_tag_disable,
+	.output				= output,
+};
+
+/* Common function to report consistent warnings based on URB status */
+static int check_urb_status(struct urb *urb)
+{
+	struct device *dev = &urb->dev->dev;
+	int status = urb->status;
+
+	switch (status) {
+	case 0:
+		return 0;
+
+	case -EOVERFLOW:
+		dev_err(dev, "%s: overflow actual length is %d\n",
+			__func__, urb->actual_length);
+		/* fall through */
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+	case -EILSEQ:
+	case -EPROTO:
+		/* device is gone, stop sending */
+		return status;
+	}
+	dev_err(dev, "%s: unknown status %d\n", __func__, status);
+
+	return -EAGAIN;
+}
+
+static void es2_destroy(struct es2_ap_dev *es2)
+{
+	struct usb_device *udev;
+	struct urb *urb;
+	int i;
+
+	debugfs_remove(es2->apb_log_enable_dentry);
+	usb_log_disable(es2);
+
+	/* Tear down everything! */
+	for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
+		urb = es2->cport_out_urb[i];
+		usb_kill_urb(urb);
+		usb_free_urb(urb);
+		es2->cport_out_urb[i] = NULL;
+		es2->cport_out_urb_busy[i] = false;	/* just to be anal */
+	}
+
+	for (i = 0; i < NUM_ARPC_IN_URB; ++i) {
+		usb_free_urb(es2->arpc_urb[i]);
+		kfree(es2->arpc_buffer[i]);
+		es2->arpc_buffer[i] = NULL;
+	}
+
+	for (i = 0; i < NUM_CPORT_IN_URB; ++i) {
+		usb_free_urb(es2->cport_in.urb[i]);
+		kfree(es2->cport_in.buffer[i]);
+		es2->cport_in.buffer[i] = NULL;
+	}
+
+	/* release reserved CDSI0 and CDSI1 cports */
+	gb_hd_cport_release_reserved(es2->hd, ES2_CPORT_CDSI1);
+	gb_hd_cport_release_reserved(es2->hd, ES2_CPORT_CDSI0);
+
+	udev = es2->usb_dev;
+	gb_hd_put(es2->hd);
+
+	usb_put_dev(udev);
+}
+
+static void cport_in_callback(struct urb *urb)
+{
+	struct gb_host_device *hd = urb->context;
+	struct device *dev = &urb->dev->dev;
+	struct gb_operation_msg_hdr *header;
+	int status = check_urb_status(urb);
+	int retval;
+	u16 cport_id;
+
+	if (status) {
+		if ((status == -EAGAIN) || (status == -EPROTO))
+			goto exit;
+
+		/* The urb is being unlinked */
+		if (status == -ENOENT || status == -ESHUTDOWN)
+			return;
+
+		dev_err(dev, "urb cport in error %d (dropped)\n", status);
+		return;
+	}
+
+	if (urb->actual_length < sizeof(*header)) {
+		dev_err(dev, "short message received\n");
+		goto exit;
+	}
+
+	/* Extract the CPort id, which is packed in the message header */
+	header = urb->transfer_buffer;
+	cport_id = gb_message_cport_unpack(header);
+
+	if (cport_id_valid(hd, cport_id)) {
+		greybus_data_rcvd(hd, cport_id, urb->transfer_buffer,
+				  urb->actual_length);
+	} else {
+		dev_err(dev, "invalid cport id %u received\n", cport_id);
+	}
+exit:
+	/* put our urb back in the request pool */
+	retval = usb_submit_urb(urb, GFP_ATOMIC);
+	if (retval)
+		dev_err(dev, "failed to resubmit in-urb: %d\n", retval);
+}
+
+static void cport_out_callback(struct urb *urb)
+{
+	struct gb_message *message = urb->context;
+	struct gb_host_device *hd = message->operation->connection->hd;
+	struct es2_ap_dev *es2 = hd_to_es2(hd);
+	int status = check_urb_status(urb);
+	unsigned long flags;
+
+	gb_message_cport_clear(message->header);
+
+	spin_lock_irqsave(&es2->cport_out_urb_lock, flags);
+	message->hcpriv = NULL;
+	spin_unlock_irqrestore(&es2->cport_out_urb_lock, flags);
+
+	/*
+	 * Tell the submitter that the message send (attempt) is
+	 * complete, and report the status.
+	 */
+	greybus_message_sent(hd, message, status);
+
+	free_urb(es2, urb);
+}
+
+static struct arpc *arpc_alloc(void *payload, u16 size, u8 type)
+{
+	struct arpc *rpc;
+
+	if (size + sizeof(*rpc->req) > ARPC_OUT_SIZE_MAX)
+		return NULL;
+
+	rpc = kzalloc(sizeof(*rpc), GFP_KERNEL);
+	if (!rpc)
+		return NULL;
+
+	INIT_LIST_HEAD(&rpc->list);
+	rpc->req = kzalloc(sizeof(*rpc->req) + size, GFP_KERNEL);
+	if (!rpc->req)
+		goto err_free_rpc;
+
+	rpc->resp = kzalloc(sizeof(*rpc->resp), GFP_KERNEL);
+	if (!rpc->resp)
+		goto err_free_req;
+
+	rpc->req->type = type;
+	rpc->req->size = cpu_to_le16(sizeof(*rpc->req) + size);
+	memcpy(rpc->req->data, payload, size);
+
+	init_completion(&rpc->response_received);
+
+	return rpc;
+
+err_free_req:
+	kfree(rpc->req);
+err_free_rpc:
+	kfree(rpc);
+
+	return NULL;
+}
+
+static void arpc_free(struct arpc *rpc)
+{
+	kfree(rpc->req);
+	kfree(rpc->resp);
+	kfree(rpc);
+}
+
+static struct arpc *arpc_find(struct es2_ap_dev *es2, __le16 id)
+{
+	struct arpc *rpc;
+
+	list_for_each_entry(rpc, &es2->arpcs, list) {
+		if (rpc->req->id == id)
+			return rpc;
+	}
+
+	return NULL;
+}
+
+static void arpc_add(struct es2_ap_dev *es2, struct arpc *rpc)
+{
+	rpc->active = true;
+	rpc->req->id = cpu_to_le16(es2->arpc_id_cycle++);
+	list_add_tail(&rpc->list, &es2->arpcs);
+}
+
+static void arpc_del(struct es2_ap_dev *es2, struct arpc *rpc)
+{
+	if (rpc->active) {
+		rpc->active = false;
+		list_del(&rpc->list);
+	}
+}
+
+static int arpc_send(struct es2_ap_dev *es2, struct arpc *rpc, int timeout)
+{
+	struct usb_device *udev = es2->usb_dev;
+	int retval;
+
+	retval = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+				 GB_APB_REQUEST_ARPC_RUN,
+				 USB_DIR_OUT | USB_TYPE_VENDOR |
+				 USB_RECIP_INTERFACE,
+				 0, 0,
+				 rpc->req, le16_to_cpu(rpc->req->size),
+				 ES2_USB_CTRL_TIMEOUT);
+	if (retval != le16_to_cpu(rpc->req->size)) {
+		dev_err(&udev->dev,
+			"failed to send ARPC request %d: %d\n",
+			rpc->req->type, retval);
+		if (retval > 0)
+			retval = -EIO;
+		return retval;
+	}
+
+	return 0;
+}
+
+static int arpc_sync(struct es2_ap_dev *es2, u8 type, void *payload,
+		     size_t size, int *result, unsigned int timeout)
+{
+	struct arpc *rpc;
+	unsigned long flags;
+	int retval;
+
+	if (result)
+		*result = 0;
+
+	rpc = arpc_alloc(payload, size, type);
+	if (!rpc)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&es2->arpc_lock, flags);
+	arpc_add(es2, rpc);
+	spin_unlock_irqrestore(&es2->arpc_lock, flags);
+
+	retval = arpc_send(es2, rpc, timeout);
+	if (retval)
+		goto out_arpc_del;
+
+	retval = wait_for_completion_interruptible_timeout(
+						&rpc->response_received,
+						msecs_to_jiffies(timeout));
+	if (retval <= 0) {
+		if (!retval)
+			retval = -ETIMEDOUT;
+		goto out_arpc_del;
+	}
+
+	if (rpc->resp->result) {
+		retval = -EREMOTEIO;
+		if (result)
+			*result = rpc->resp->result;
+	} else {
+		retval = 0;
+	}
+
+out_arpc_del:
+	spin_lock_irqsave(&es2->arpc_lock, flags);
+	arpc_del(es2, rpc);
+	spin_unlock_irqrestore(&es2->arpc_lock, flags);
+	arpc_free(rpc);
+
+	if (retval < 0 && retval != -EREMOTEIO) {
+		dev_err(&es2->usb_dev->dev,
+			"failed to execute ARPC: %d\n", retval);
+	}
+
+	return retval;
+}
+
+static void arpc_in_callback(struct urb *urb)
+{
+	struct es2_ap_dev *es2 = urb->context;
+	struct device *dev = &urb->dev->dev;
+	int status = check_urb_status(urb);
+	struct arpc *rpc;
+	struct arpc_response_message *resp;
+	unsigned long flags;
+	int retval;
+
+	if (status) {
+		if ((status == -EAGAIN) || (status == -EPROTO))
+			goto exit;
+
+		/* The urb is being unlinked */
+		if (status == -ENOENT || status == -ESHUTDOWN)
+			return;
+
+		dev_err(dev, "arpc in-urb error %d (dropped)\n", status);
+		return;
+	}
+
+	if (urb->actual_length < sizeof(*resp)) {
+		dev_err(dev, "short aprc response received\n");
+		goto exit;
+	}
+
+	resp = urb->transfer_buffer;
+	spin_lock_irqsave(&es2->arpc_lock, flags);
+	rpc = arpc_find(es2, resp->id);
+	if (!rpc) {
+		dev_err(dev, "invalid arpc response id received: %u\n",
+			le16_to_cpu(resp->id));
+		spin_unlock_irqrestore(&es2->arpc_lock, flags);
+		goto exit;
+	}
+
+	arpc_del(es2, rpc);
+	memcpy(rpc->resp, resp, sizeof(*resp));
+	complete(&rpc->response_received);
+	spin_unlock_irqrestore(&es2->arpc_lock, flags);
+
+exit:
+	/* put our urb back in the request pool */
+	retval = usb_submit_urb(urb, GFP_ATOMIC);
+	if (retval)
+		dev_err(dev, "failed to resubmit arpc in-urb: %d\n", retval);
+}
+
+#define APB1_LOG_MSG_SIZE	64
+static void apb_log_get(struct es2_ap_dev *es2, char *buf)
+{
+	int retval;
+
+	do {
+		retval = usb_control_msg(es2->usb_dev,
+					 usb_rcvctrlpipe(es2->usb_dev, 0),
+					 GB_APB_REQUEST_LOG,
+					 USB_DIR_IN | USB_TYPE_VENDOR |
+					 USB_RECIP_INTERFACE,
+					 0x00, 0x00,
+					 buf,
+					 APB1_LOG_MSG_SIZE,
+					 ES2_USB_CTRL_TIMEOUT);
+		if (retval > 0)
+			kfifo_in(&es2->apb_log_fifo, buf, retval);
+	} while (retval > 0);
+}
+
+static int apb_log_poll(void *data)
+{
+	struct es2_ap_dev *es2 = data;
+	char *buf;
+
+	buf = kmalloc(APB1_LOG_MSG_SIZE, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	while (!kthread_should_stop()) {
+		msleep(1000);
+		apb_log_get(es2, buf);
+	}
+
+	kfree(buf);
+
+	return 0;
+}
+
+static ssize_t apb_log_read(struct file *f, char __user *buf,
+			    size_t count, loff_t *ppos)
+{
+	struct es2_ap_dev *es2 = file_inode(f)->i_private;
+	ssize_t ret;
+	size_t copied;
+	char *tmp_buf;
+
+	if (count > APB1_LOG_SIZE)
+		count = APB1_LOG_SIZE;
+
+	tmp_buf = kmalloc(count, GFP_KERNEL);
+	if (!tmp_buf)
+		return -ENOMEM;
+
+	copied = kfifo_out(&es2->apb_log_fifo, tmp_buf, count);
+	ret = simple_read_from_buffer(buf, count, ppos, tmp_buf, copied);
+
+	kfree(tmp_buf);
+
+	return ret;
+}
+
+static const struct file_operations apb_log_fops = {
+	.read	= apb_log_read,
+};
+
+static void usb_log_enable(struct es2_ap_dev *es2)
+{
+	if (!IS_ERR_OR_NULL(es2->apb_log_task))
+		return;
+
+	/* get log from APB1 */
+	es2->apb_log_task = kthread_run(apb_log_poll, es2, "apb_log");
+	if (IS_ERR(es2->apb_log_task))
+		return;
+	/* XXX We will need to rename this per APB */
+	es2->apb_log_dentry = debugfs_create_file("apb_log", 0444,
+						  gb_debugfs_get(), es2,
+						  &apb_log_fops);
+}
+
+static void usb_log_disable(struct es2_ap_dev *es2)
+{
+	if (IS_ERR_OR_NULL(es2->apb_log_task))
+		return;
+
+	debugfs_remove(es2->apb_log_dentry);
+	es2->apb_log_dentry = NULL;
+
+	kthread_stop(es2->apb_log_task);
+	es2->apb_log_task = NULL;
+}
+
+static ssize_t apb_log_enable_read(struct file *f, char __user *buf,
+				   size_t count, loff_t *ppos)
+{
+	struct es2_ap_dev *es2 = file_inode(f)->i_private;
+	int enable = !IS_ERR_OR_NULL(es2->apb_log_task);
+	char tmp_buf[3];
+
+	sprintf(tmp_buf, "%d\n", enable);
+	return simple_read_from_buffer(buf, count, ppos, tmp_buf, 3);
+}
+
+static ssize_t apb_log_enable_write(struct file *f, const char __user *buf,
+				    size_t count, loff_t *ppos)
+{
+	int enable;
+	ssize_t retval;
+	struct es2_ap_dev *es2 = file_inode(f)->i_private;
+
+	retval = kstrtoint_from_user(buf, count, 10, &enable);
+	if (retval)
+		return retval;
+
+	if (enable)
+		usb_log_enable(es2);
+	else
+		usb_log_disable(es2);
+
+	return count;
+}
+
+static const struct file_operations apb_log_enable_fops = {
+	.read	= apb_log_enable_read,
+	.write	= apb_log_enable_write,
+};
+
+static int apb_get_cport_count(struct usb_device *udev)
+{
+	int retval;
+	__le16 *cport_count;
+
+	cport_count = kzalloc(sizeof(*cport_count), GFP_KERNEL);
+	if (!cport_count)
+		return -ENOMEM;
+
+	retval = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
+				 GB_APB_REQUEST_CPORT_COUNT,
+				 USB_DIR_IN | USB_TYPE_VENDOR |
+				 USB_RECIP_INTERFACE, 0, 0, cport_count,
+				 sizeof(*cport_count), ES2_USB_CTRL_TIMEOUT);
+	if (retval != sizeof(*cport_count)) {
+		dev_err(&udev->dev, "Cannot retrieve CPort count: %d\n",
+			retval);
+
+		if (retval >= 0)
+			retval = -EIO;
+
+		goto out;
+	}
+
+	retval = le16_to_cpu(*cport_count);
+
+	/* We need to fit a CPort ID in one byte of a message header */
+	if (retval > U8_MAX) {
+		retval = U8_MAX;
+		dev_warn(&udev->dev, "Limiting number of CPorts to U8_MAX\n");
+	}
+
+out:
+	kfree(cport_count);
+	return retval;
+}
+
+/*
+ * The ES2 USB Bridge device has 15 endpoints
+ * 1 Control - usual USB stuff + AP -> APBridgeA messages
+ * 7 Bulk IN - CPort data in
+ * 7 Bulk OUT - CPort data out
+ */
+static int ap_probe(struct usb_interface *interface,
+		    const struct usb_device_id *id)
+{
+	struct es2_ap_dev *es2;
+	struct gb_host_device *hd;
+	struct usb_device *udev;
+	struct usb_host_interface *iface_desc;
+	struct usb_endpoint_descriptor *endpoint;
+	__u8 ep_addr;
+	int retval;
+	int i;
+	int num_cports;
+	bool bulk_out_found = false;
+	bool bulk_in_found = false;
+	bool arpc_in_found = false;
+
+	udev = usb_get_dev(interface_to_usbdev(interface));
+
+	num_cports = apb_get_cport_count(udev);
+	if (num_cports < 0) {
+		usb_put_dev(udev);
+		dev_err(&udev->dev, "Cannot retrieve CPort count: %d\n",
+			num_cports);
+		return num_cports;
+	}
+
+	hd = gb_hd_create(&es2_driver, &udev->dev, ES2_GBUF_MSG_SIZE_MAX,
+			  num_cports);
+	if (IS_ERR(hd)) {
+		usb_put_dev(udev);
+		return PTR_ERR(hd);
+	}
+
+	es2 = hd_to_es2(hd);
+	es2->hd = hd;
+	es2->usb_intf = interface;
+	es2->usb_dev = udev;
+	spin_lock_init(&es2->cport_out_urb_lock);
+	INIT_KFIFO(es2->apb_log_fifo);
+	usb_set_intfdata(interface, es2);
+
+	/*
+	 * Reserve the CDSI0 and CDSI1 CPorts so they won't be allocated
+	 * dynamically.
+	 */
+	retval = gb_hd_cport_reserve(hd, ES2_CPORT_CDSI0);
+	if (retval)
+		goto error;
+	retval = gb_hd_cport_reserve(hd, ES2_CPORT_CDSI1);
+	if (retval)
+		goto error;
+
+	/* find all bulk endpoints */
+	iface_desc = interface->cur_altsetting;
+	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+		endpoint = &iface_desc->endpoint[i].desc;
+		ep_addr = endpoint->bEndpointAddress;
+
+		if (usb_endpoint_is_bulk_in(endpoint)) {
+			if (!bulk_in_found) {
+				es2->cport_in.endpoint = ep_addr;
+				bulk_in_found = true;
+			} else if (!arpc_in_found) {
+				es2->arpc_endpoint_in = ep_addr;
+				arpc_in_found = true;
+			} else {
+				dev_warn(&udev->dev,
+					 "Unused bulk IN endpoint found: 0x%02x\n",
+					 ep_addr);
+			}
+			continue;
+		}
+		if (usb_endpoint_is_bulk_out(endpoint)) {
+			if (!bulk_out_found) {
+				es2->cport_out_endpoint = ep_addr;
+				bulk_out_found = true;
+			} else {
+				dev_warn(&udev->dev,
+					 "Unused bulk OUT endpoint found: 0x%02x\n",
+					 ep_addr);
+			}
+			continue;
+		}
+		dev_warn(&udev->dev,
+			 "Unknown endpoint type found, address 0x%02x\n",
+			 ep_addr);
+	}
+	if (!bulk_in_found || !arpc_in_found || !bulk_out_found) {
+		dev_err(&udev->dev, "Not enough endpoints found in device, aborting!\n");
+		retval = -ENODEV;
+		goto error;
+	}
+
+	/* Allocate buffers for our cport in messages */
+	for (i = 0; i < NUM_CPORT_IN_URB; ++i) {
+		struct urb *urb;
+		u8 *buffer;
+
+		urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!urb) {
+			retval = -ENOMEM;
+			goto error;
+		}
+		es2->cport_in.urb[i] = urb;
+
+		buffer = kmalloc(ES2_GBUF_MSG_SIZE_MAX, GFP_KERNEL);
+		if (!buffer) {
+			retval = -ENOMEM;
+			goto error;
+		}
+
+		usb_fill_bulk_urb(urb, udev,
+				  usb_rcvbulkpipe(udev, es2->cport_in.endpoint),
+				  buffer, ES2_GBUF_MSG_SIZE_MAX,
+				  cport_in_callback, hd);
+
+		es2->cport_in.buffer[i] = buffer;
+	}
+
+	/* Allocate buffers for ARPC in messages */
+	for (i = 0; i < NUM_ARPC_IN_URB; ++i) {
+		struct urb *urb;
+		u8 *buffer;
+
+		urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!urb) {
+			retval = -ENOMEM;
+			goto error;
+		}
+		es2->arpc_urb[i] = urb;
+
+		buffer = kmalloc(ARPC_IN_SIZE_MAX, GFP_KERNEL);
+		if (!buffer) {
+			retval = -ENOMEM;
+			goto error;
+		}
+
+		usb_fill_bulk_urb(urb, udev,
+				  usb_rcvbulkpipe(udev,
+						  es2->arpc_endpoint_in),
+				  buffer, ARPC_IN_SIZE_MAX,
+				  arpc_in_callback, es2);
+
+		es2->arpc_buffer[i] = buffer;
+	}
+
+	/* Allocate urbs for our CPort OUT messages */
+	for (i = 0; i < NUM_CPORT_OUT_URB; ++i) {
+		struct urb *urb;
+
+		urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!urb) {
+			retval = -ENOMEM;
+			goto error;
+		}
+
+		es2->cport_out_urb[i] = urb;
+		es2->cport_out_urb_busy[i] = false;	/* just to be anal */
+	}
+
+	/* XXX We will need to rename this per APB */
+	es2->apb_log_enable_dentry = debugfs_create_file("apb_log_enable",
+							 0644,
+							 gb_debugfs_get(), es2,
+							 &apb_log_enable_fops);
+
+	INIT_LIST_HEAD(&es2->arpcs);
+	spin_lock_init(&es2->arpc_lock);
+
+	retval = es2_arpc_in_enable(es2);
+	if (retval)
+		goto error;
+
+	retval = gb_hd_add(hd);
+	if (retval)
+		goto err_disable_arpc_in;
+
+	retval = es2_cport_in_enable(es2, &es2->cport_in);
+	if (retval)
+		goto err_hd_del;
+
+	return 0;
+
+err_hd_del:
+	gb_hd_del(hd);
+err_disable_arpc_in:
+	es2_arpc_in_disable(es2);
+error:
+	es2_destroy(es2);
+
+	return retval;
+}
+
+static void ap_disconnect(struct usb_interface *interface)
+{
+	struct es2_ap_dev *es2 = usb_get_intfdata(interface);
+
+	gb_hd_del(es2->hd);
+
+	es2_cport_in_disable(es2, &es2->cport_in);
+	es2_arpc_in_disable(es2);
+
+	es2_destroy(es2);
+}
+
+static struct usb_driver es2_ap_driver = {
+	.name =		"es2_ap_driver",
+	.probe =	ap_probe,
+	.disconnect =	ap_disconnect,
+	.id_table =	id_table,
+	.soft_unbind =	1,
+};
+
+module_usb_driver(es2_ap_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");