usbtmc.c 29.9 KB
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/**
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 * drivers/usb/class/usbtmc.c - USB Test & Measurement class driver
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 *
 * Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
 * Copyright (C) 2008 Novell, Inc.
 * Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * 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.
 *
 * The GNU General Public License is available at
 * http://www.gnu.org/copyleft/gpl.html.
 */

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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/kref.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
#include <linux/usb.h>
#include <linux/usb/tmc.h>


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#define RIGOL			1
#define USBTMC_HEADER_SIZE	12
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#define USBTMC_MINOR_BASE	176

/*
 * Size of driver internal IO buffer. Must be multiple of 4 and at least as
 * large as wMaxPacketSize (which is usually 512 bytes).
 */
#define USBTMC_SIZE_IOBUFFER	2048

/* Default USB timeout (in milliseconds) */
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#define USBTMC_TIMEOUT		5000
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/*
 * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
 * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
 * packet is never read.
 */
#define USBTMC_MAX_READS_TO_CLEAR_BULK_IN	100

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static const struct usb_device_id usbtmc_devices[] = {
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	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
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	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
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	{ 0, } /* terminating entry */
};
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MODULE_DEVICE_TABLE(usb, usbtmc_devices);
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/*
 * This structure is the capabilities for the device
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 * See section 4.2.1.8 of the USBTMC specification,
 * and section 4.2.2 of the USBTMC usb488 subclass
 * specification for details.
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 */
struct usbtmc_dev_capabilities {
	__u8 interface_capabilities;
	__u8 device_capabilities;
	__u8 usb488_interface_capabilities;
	__u8 usb488_device_capabilities;
};

/* This structure holds private data for each USBTMC device. One copy is
 * allocated for each USBTMC device in the driver's probe function.
 */
struct usbtmc_device_data {
	const struct usb_device_id *id;
	struct usb_device *usb_dev;
	struct usb_interface *intf;

	unsigned int bulk_in;
	unsigned int bulk_out;

	u8 bTag;
	u8 bTag_last_write;	/* needed for abort */
	u8 bTag_last_read;	/* needed for abort */

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	u8 rigol_quirk;

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	/* attributes from the USB TMC spec for this device */
	u8 TermChar;
	bool TermCharEnabled;
	bool auto_abort;

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	bool zombie; /* fd of disconnected device */

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	struct usbtmc_dev_capabilities	capabilities;
	struct kref kref;
	struct mutex io_mutex;	/* only one i/o function running at a time */
};
#define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)

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struct usbtmc_ID_rigol_quirk {
	__u16 idVendor;
	__u16 idProduct;
};

static const struct usbtmc_ID_rigol_quirk usbtmc_id_quirk[] = {
	{ 0x1ab1, 0x0588 },
	{ 0, 0 }
};

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/* Forward declarations */
static struct usb_driver usbtmc_driver;

static void usbtmc_delete(struct kref *kref)
{
	struct usbtmc_device_data *data = to_usbtmc_data(kref);

	usb_put_dev(data->usb_dev);
}

static int usbtmc_open(struct inode *inode, struct file *filp)
{
	struct usb_interface *intf;
	struct usbtmc_device_data *data;
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	int retval = 0;
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	intf = usb_find_interface(&usbtmc_driver, iminor(inode));
	if (!intf) {
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		pr_err("can not find device for minor %d", iminor(inode));
		return -ENODEV;
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	}

	data = usb_get_intfdata(intf);
	kref_get(&data->kref);

	/* Store pointer in file structure's private data field */
	filp->private_data = data;

	return retval;
}

static int usbtmc_release(struct inode *inode, struct file *file)
{
	struct usbtmc_device_data *data = file->private_data;

	kref_put(&data->kref, usbtmc_delete);
	return 0;
}

static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
{
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	u8 *buffer;
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	struct device *dev;
	int rv;
	int n;
	int actual;
	struct usb_host_interface *current_setting;
	int max_size;

	dev = &data->intf->dev;
	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	rv = usb_control_msg(data->usb_dev,
			     usb_rcvctrlpipe(data->usb_dev, 0),
			     USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
			     data->bTag_last_read, data->bulk_in,
			     buffer, 2, USBTMC_TIMEOUT);

	if (rv < 0) {
		dev_err(dev, "usb_control_msg returned %d\n", rv);
		goto exit;
	}

	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);

	if (buffer[0] == USBTMC_STATUS_FAILED) {
		rv = 0;
		goto exit;
	}

	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
			buffer[0]);
		rv = -EPERM;
		goto exit;
	}

	max_size = 0;
	current_setting = data->intf->cur_altsetting;
	for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
		if (current_setting->endpoint[n].desc.bEndpointAddress ==
			data->bulk_in)
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			max_size = usb_endpoint_maxp(&current_setting->endpoint[n].desc);
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	if (max_size == 0) {
		dev_err(dev, "Couldn't get wMaxPacketSize\n");
		rv = -EPERM;
		goto exit;
	}

	dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);

	n = 0;

	do {
		dev_dbg(dev, "Reading from bulk in EP\n");

		rv = usb_bulk_msg(data->usb_dev,
				  usb_rcvbulkpipe(data->usb_dev,
						  data->bulk_in),
				  buffer, USBTMC_SIZE_IOBUFFER,
				  &actual, USBTMC_TIMEOUT);

		n++;

		if (rv < 0) {
			dev_err(dev, "usb_bulk_msg returned %d\n", rv);
			goto exit;
		}
	} while ((actual == max_size) &&
		 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));

	if (actual == max_size) {
		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
		rv = -EPERM;
		goto exit;
	}

	n = 0;

usbtmc_abort_bulk_in_status:
	rv = usb_control_msg(data->usb_dev,
			     usb_rcvctrlpipe(data->usb_dev, 0),
			     USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
			     0, data->bulk_in, buffer, 0x08,
			     USBTMC_TIMEOUT);

	if (rv < 0) {
		dev_err(dev, "usb_control_msg returned %d\n", rv);
		goto exit;
	}

	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);

	if (buffer[0] == USBTMC_STATUS_SUCCESS) {
		rv = 0;
		goto exit;
	}

	if (buffer[0] != USBTMC_STATUS_PENDING) {
		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
		rv = -EPERM;
		goto exit;
	}

	if (buffer[1] == 1)
		do {
			dev_dbg(dev, "Reading from bulk in EP\n");

			rv = usb_bulk_msg(data->usb_dev,
					  usb_rcvbulkpipe(data->usb_dev,
							  data->bulk_in),
					  buffer, USBTMC_SIZE_IOBUFFER,
					  &actual, USBTMC_TIMEOUT);

			n++;

			if (rv < 0) {
				dev_err(dev, "usb_bulk_msg returned %d\n", rv);
				goto exit;
			}
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		} while ((actual == max_size) &&
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			 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));

	if (actual == max_size) {
		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
		rv = -EPERM;
		goto exit;
	}

	goto usbtmc_abort_bulk_in_status;

exit:
	kfree(buffer);
	return rv;

}

static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
{
	struct device *dev;
	u8 *buffer;
	int rv;
	int n;

	dev = &data->intf->dev;

	buffer = kmalloc(8, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	rv = usb_control_msg(data->usb_dev,
			     usb_rcvctrlpipe(data->usb_dev, 0),
			     USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
			     data->bTag_last_write, data->bulk_out,
			     buffer, 2, USBTMC_TIMEOUT);

	if (rv < 0) {
		dev_err(dev, "usb_control_msg returned %d\n", rv);
		goto exit;
	}

	dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);

	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
		dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
			buffer[0]);
		rv = -EPERM;
		goto exit;
	}

	n = 0;

usbtmc_abort_bulk_out_check_status:
	rv = usb_control_msg(data->usb_dev,
			     usb_rcvctrlpipe(data->usb_dev, 0),
			     USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
			     0, data->bulk_out, buffer, 0x08,
			     USBTMC_TIMEOUT);
	n++;
	if (rv < 0) {
		dev_err(dev, "usb_control_msg returned %d\n", rv);
		goto exit;
	}

	dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);

	if (buffer[0] == USBTMC_STATUS_SUCCESS)
		goto usbtmc_abort_bulk_out_clear_halt;

	if ((buffer[0] == USBTMC_STATUS_PENDING) &&
	    (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
		goto usbtmc_abort_bulk_out_check_status;

	rv = -EPERM;
	goto exit;

usbtmc_abort_bulk_out_clear_halt:
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	rv = usb_clear_halt(data->usb_dev,
			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
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	if (rv < 0) {
		dev_err(dev, "usb_control_msg returned %d\n", rv);
		goto exit;
	}
	rv = 0;

exit:
	kfree(buffer);
	return rv;
}

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/*
 * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
 * @transfer_size: number of bytes to request from the device.
 *
 * See the USBTMC specification, Table 4.
 *
 * Also updates bTag_last_write.
 */
static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t transfer_size)
{
	int retval;
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	u8 *buffer;
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	int actual;

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	buffer = kmalloc(USBTMC_HEADER_SIZE, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;
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	/* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
	 * Refer to class specs for details
	 */
	buffer[0] = 2;
	buffer[1] = data->bTag;
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	buffer[2] = ~data->bTag;
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	buffer[3] = 0; /* Reserved */
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	buffer[4] = transfer_size >> 0;
	buffer[5] = transfer_size >> 8;
	buffer[6] = transfer_size >> 16;
	buffer[7] = transfer_size >> 24;
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	buffer[8] = data->TermCharEnabled * 2;
	/* Use term character? */
	buffer[9] = data->TermChar;
	buffer[10] = 0; /* Reserved */
	buffer[11] = 0; /* Reserved */

	/* Send bulk URB */
	retval = usb_bulk_msg(data->usb_dev,
			      usb_sndbulkpipe(data->usb_dev,
					      data->bulk_out),
			      buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);

	/* Store bTag (in case we need to abort) */
	data->bTag_last_write = data->bTag;

	/* Increment bTag -- and increment again if zero */
	data->bTag++;
	if (!data->bTag)
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		data->bTag++;
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	kfree(buffer);
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	if (retval < 0) {
		dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
		return retval;
	}

	return 0;
}

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static ssize_t usbtmc_read(struct file *filp, char __user *buf,
			   size_t count, loff_t *f_pos)
{
	struct usbtmc_device_data *data;
	struct device *dev;
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	u32 n_characters;
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	u8 *buffer;
	int actual;
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	size_t done;
	size_t remaining;
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	int retval;
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	size_t this_part;
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	/* Get pointer to private data structure */
	data = filp->private_data;
	dev = &data->intf->dev;

	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	mutex_lock(&data->io_mutex);
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	if (data->zombie) {
		retval = -ENODEV;
		goto exit;
	}
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	if (data->rigol_quirk) {
		dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);

		retval = send_request_dev_dep_msg_in(data, count);

		if (retval < 0) {
			if (data->auto_abort)
				usbtmc_ioctl_abort_bulk_out(data);
			goto exit;
		}
	}

	/* Loop until we have fetched everything we requested */
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	remaining = count;
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	this_part = remaining;
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	done = 0;

	while (remaining > 0) {
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		if (!data->rigol_quirk) {
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			dev_dbg(dev, "usb_bulk_msg_in: remaining(%zu), count(%zu)\n", remaining, count);

			if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3)
				this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3;
			else
				this_part = remaining;
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			retval = send_request_dev_dep_msg_in(data, this_part);
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			if (retval < 0) {
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			dev_err(dev, "usb_bulk_msg returned %d\n", retval);
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				if (data->auto_abort)
					usbtmc_ioctl_abort_bulk_out(data);
				goto exit;
			}
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		}

		/* Send bulk URB */
		retval = usb_bulk_msg(data->usb_dev,
				      usb_rcvbulkpipe(data->usb_dev,
						      data->bulk_in),
				      buffer, USBTMC_SIZE_IOBUFFER, &actual,
				      USBTMC_TIMEOUT);

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		dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu), remaining(%zu), actual(%d)\n", retval, done, remaining, actual);

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		/* Store bTag (in case we need to abort) */
		data->bTag_last_read = data->bTag;

		if (retval < 0) {
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			dev_dbg(dev, "Unable to read data, error %d\n", retval);
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			if (data->auto_abort)
				usbtmc_ioctl_abort_bulk_in(data);
			goto exit;
		}

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		/* Parse header in first packet */
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		if ((done == 0) || !data->rigol_quirk) {
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			/* Sanity checks for the header */
			if (actual < USBTMC_HEADER_SIZE) {
				dev_err(dev, "Device sent too small first packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
				if (data->auto_abort)
					usbtmc_ioctl_abort_bulk_in(data);
				goto exit;
			}
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			if (buffer[0] != 2) {
				dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n", buffer[0]);
				if (data->auto_abort)
					usbtmc_ioctl_abort_bulk_in(data);
				goto exit;
			}
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			if (buffer[1] != data->bTag_last_write) {
				dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n", buffer[1], data->bTag_last_write);
				if (data->auto_abort)
					usbtmc_ioctl_abort_bulk_in(data);
				goto exit;
			}
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			/* How many characters did the instrument send? */
			n_characters = buffer[4] +
				       (buffer[5] << 8) +
				       (buffer[6] << 16) +
				       (buffer[7] << 24);
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			if (n_characters > this_part) {
				dev_err(dev, "Device wants to return more data than requested: %u > %zu\n", n_characters, count);
				if (data->auto_abort)
					usbtmc_ioctl_abort_bulk_in(data);
				goto exit;
			}

			/* Remove the USBTMC header */
			actual -= USBTMC_HEADER_SIZE;

			/* Check if the message is smaller than requested */
			if (data->rigol_quirk) {
				if (remaining > n_characters)
					remaining = n_characters;
				/* Remove padding if it exists */
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				if (actual > remaining)
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					actual = remaining;
			}
			else {
				if (this_part > n_characters)
					this_part = n_characters;
				/* Remove padding if it exists */
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				if (actual > this_part)
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					actual = this_part;
			}

			dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n", n_characters, buffer[8]);

			remaining -= actual;

			/* Terminate if end-of-message bit received from device */
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			if ((buffer[8] & 0x01) && (actual >= n_characters))
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				remaining = 0;

			dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p), buffer(%p) done(%zu)\n", remaining,buf,buffer,done);


			/* Copy buffer to user space */
			if (copy_to_user(buf + done, &buffer[USBTMC_HEADER_SIZE], actual)) {
				/* There must have been an addressing problem */
				retval = -EFAULT;
				goto exit;
			}
			done += actual;
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		}
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		else  {
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			if (actual > remaining)
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				actual = remaining;
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			remaining -= actual;

			dev_dbg(dev, "Bulk-IN header cont: actual(%u), done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done, remaining,buf,buffer);

			/* Copy buffer to user space */
			if (copy_to_user(buf + done, buffer, actual)) {
				/* There must have been an addressing problem */
				retval = -EFAULT;
				goto exit;
			}
			done += actual;
		}
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	}

	/* Update file position value */
	*f_pos = *f_pos + done;
	retval = done;

exit:
	mutex_unlock(&data->io_mutex);
	kfree(buffer);
	return retval;
}

static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
			    size_t count, loff_t *f_pos)
{
	struct usbtmc_device_data *data;
	u8 *buffer;
	int retval;
	int actual;
	unsigned long int n_bytes;
	int remaining;
	int done;
	int this_part;

	data = filp->private_data;

	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	mutex_lock(&data->io_mutex);
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	if (data->zombie) {
		retval = -ENODEV;
		goto exit;
	}
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	remaining = count;
	done = 0;

	while (remaining > 0) {
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		if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
			this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
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			buffer[8] = 0;
		} else {
			this_part = remaining;
			buffer[8] = 1;
		}

		/* Setup IO buffer for DEV_DEP_MSG_OUT message */
		buffer[0] = 1;
		buffer[1] = data->bTag;
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		buffer[2] = ~data->bTag;
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		buffer[3] = 0; /* Reserved */
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		buffer[4] = this_part >> 0;
		buffer[5] = this_part >> 8;
		buffer[6] = this_part >> 16;
		buffer[7] = this_part >> 24;
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		/* buffer[8] is set above... */
		buffer[9] = 0; /* Reserved */
		buffer[10] = 0; /* Reserved */
		buffer[11] = 0; /* Reserved */

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		if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
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			retval = -EFAULT;
			goto exit;
		}

671 672
		n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
		memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
673

674 675 676 677 678 679 680 681 682 683
		do {
			retval = usb_bulk_msg(data->usb_dev,
					      usb_sndbulkpipe(data->usb_dev,
							      data->bulk_out),
					      buffer, n_bytes,
					      &actual, USBTMC_TIMEOUT);
			if (retval != 0)
				break;
			n_bytes -= actual;
		} while (n_bytes);
684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751

		data->bTag_last_write = data->bTag;
		data->bTag++;

		if (!data->bTag)
			data->bTag++;

		if (retval < 0) {
			dev_err(&data->intf->dev,
				"Unable to send data, error %d\n", retval);
			if (data->auto_abort)
				usbtmc_ioctl_abort_bulk_out(data);
			goto exit;
		}

		remaining -= this_part;
		done += this_part;
	}

	retval = count;
exit:
	mutex_unlock(&data->io_mutex);
	kfree(buffer);
	return retval;
}

static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
{
	struct usb_host_interface *current_setting;
	struct usb_endpoint_descriptor *desc;
	struct device *dev;
	u8 *buffer;
	int rv;
	int n;
	int actual;
	int max_size;

	dev = &data->intf->dev;

	dev_dbg(dev, "Sending INITIATE_CLEAR request\n");

	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	rv = usb_control_msg(data->usb_dev,
			     usb_rcvctrlpipe(data->usb_dev, 0),
			     USBTMC_REQUEST_INITIATE_CLEAR,
			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
			     0, 0, buffer, 1, USBTMC_TIMEOUT);
	if (rv < 0) {
		dev_err(dev, "usb_control_msg returned %d\n", rv);
		goto exit;
	}

	dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);

	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
		dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
		rv = -EPERM;
		goto exit;
	}

	max_size = 0;
	current_setting = data->intf->cur_altsetting;
	for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
		desc = &current_setting->endpoint[n].desc;
		if (desc->bEndpointAddress == data->bulk_in)
752
			max_size = usb_endpoint_maxp(desc);
753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819
	}

	if (max_size == 0) {
		dev_err(dev, "Couldn't get wMaxPacketSize\n");
		rv = -EPERM;
		goto exit;
	}

	dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);

	n = 0;

usbtmc_clear_check_status:

	dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");

	rv = usb_control_msg(data->usb_dev,
			     usb_rcvctrlpipe(data->usb_dev, 0),
			     USBTMC_REQUEST_CHECK_CLEAR_STATUS,
			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
			     0, 0, buffer, 2, USBTMC_TIMEOUT);
	if (rv < 0) {
		dev_err(dev, "usb_control_msg returned %d\n", rv);
		goto exit;
	}

	dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);

	if (buffer[0] == USBTMC_STATUS_SUCCESS)
		goto usbtmc_clear_bulk_out_halt;

	if (buffer[0] != USBTMC_STATUS_PENDING) {
		dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
		rv = -EPERM;
		goto exit;
	}

	if (buffer[1] == 1)
		do {
			dev_dbg(dev, "Reading from bulk in EP\n");

			rv = usb_bulk_msg(data->usb_dev,
					  usb_rcvbulkpipe(data->usb_dev,
							  data->bulk_in),
					  buffer, USBTMC_SIZE_IOBUFFER,
					  &actual, USBTMC_TIMEOUT);
			n++;

			if (rv < 0) {
				dev_err(dev, "usb_control_msg returned %d\n",
					rv);
				goto exit;
			}
		} while ((actual == max_size) &&
			  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));

	if (actual == max_size) {
		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
		rv = -EPERM;
		goto exit;
	}

	goto usbtmc_clear_check_status;

usbtmc_clear_bulk_out_halt:

820 821
	rv = usb_clear_halt(data->usb_dev,
			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
822 823 824 825 826 827 828 829 830 831 832 833 834 835 836
	if (rv < 0) {
		dev_err(dev, "usb_control_msg returned %d\n", rv);
		goto exit;
	}
	rv = 0;

exit:
	kfree(buffer);
	return rv;
}

static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
{
	int rv;

837 838
	rv = usb_clear_halt(data->usb_dev,
			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
839 840 841 842

	if (rv < 0) {
		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
			rv);
843
		return rv;
844
	}
845
	return 0;
846 847 848 849 850 851
}

static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
{
	int rv;

852 853
	rv = usb_clear_halt(data->usb_dev,
			    usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
854 855 856 857

	if (rv < 0) {
		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
			rv);
858
		return rv;
859
	}
860
	return 0;
861 862 863 864 865 866
}

static int get_capabilities(struct usbtmc_device_data *data)
{
	struct device *dev = &data->usb_dev->dev;
	char *buffer;
867
	int rv = 0;
868 869 870 871 872 873 874 875 876 877 878

	buffer = kmalloc(0x18, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
			     USBTMC_REQUEST_GET_CAPABILITIES,
			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
			     0, 0, buffer, 0x18, USBTMC_TIMEOUT);
	if (rv < 0) {
		dev_err(dev, "usb_control_msg returned %d\n", rv);
879
		goto err_out;
880 881 882 883 884
	}

	dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
		dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
885 886
		rv = -EPERM;
		goto err_out;
887
	}
888 889 890 891
	dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
	dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
	dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
	dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
892 893 894 895 896

	data->capabilities.interface_capabilities = buffer[4];
	data->capabilities.device_capabilities = buffer[5];
	data->capabilities.usb488_interface_capabilities = buffer[14];
	data->capabilities.usb488_device_capabilities = buffer[15];
897
	rv = 0;
898

899
err_out:
900
	kfree(buffer);
901
	return rv;
902 903 904
}

#define capability_attribute(name)					\
905
static ssize_t name##_show(struct device *dev,				\
906 907 908 909 910 911 912
			   struct device_attribute *attr, char *buf)	\
{									\
	struct usb_interface *intf = to_usb_interface(dev);		\
	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
									\
	return sprintf(buf, "%d\n", data->capabilities.name);		\
}									\
913
static DEVICE_ATTR_RO(name)
914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931

capability_attribute(interface_capabilities);
capability_attribute(device_capabilities);
capability_attribute(usb488_interface_capabilities);
capability_attribute(usb488_device_capabilities);

static struct attribute *capability_attrs[] = {
	&dev_attr_interface_capabilities.attr,
	&dev_attr_device_capabilities.attr,
	&dev_attr_usb488_interface_capabilities.attr,
	&dev_attr_usb488_device_capabilities.attr,
	NULL,
};

static struct attribute_group capability_attr_grp = {
	.attrs = capability_attrs,
};

932
static ssize_t TermChar_show(struct device *dev,
933 934 935 936 937 938 939 940
			     struct device_attribute *attr, char *buf)
{
	struct usb_interface *intf = to_usb_interface(dev);
	struct usbtmc_device_data *data = usb_get_intfdata(intf);

	return sprintf(buf, "%c\n", data->TermChar);
}

941
static ssize_t TermChar_store(struct device *dev,
942 943 944 945 946 947 948 949 950 951 952
			      struct device_attribute *attr,
			      const char *buf, size_t count)
{
	struct usb_interface *intf = to_usb_interface(dev);
	struct usbtmc_device_data *data = usb_get_intfdata(intf);

	if (count < 1)
		return -EINVAL;
	data->TermChar = buf[0];
	return count;
}
953
static DEVICE_ATTR_RW(TermChar);
954 955

#define data_attribute(name)						\
956
static ssize_t name##_show(struct device *dev,				\
957 958 959 960 961 962 963
			   struct device_attribute *attr, char *buf)	\
{									\
	struct usb_interface *intf = to_usb_interface(dev);		\
	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
									\
	return sprintf(buf, "%d\n", data->name);			\
}									\
964
static ssize_t name##_store(struct device *dev,				\
965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981
			    struct device_attribute *attr,		\
			    const char *buf, size_t count)		\
{									\
	struct usb_interface *intf = to_usb_interface(dev);		\
	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
	ssize_t result;							\
	unsigned val;							\
									\
	result = sscanf(buf, "%u\n", &val);				\
	if (result != 1)						\
		result = -EINVAL;					\
	data->name = val;						\
	if (result < 0)							\
		return result;						\
	else								\
		return count;						\
}									\
982
static DEVICE_ATTR_RW(name)
983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041

data_attribute(TermCharEnabled);
data_attribute(auto_abort);

static struct attribute *data_attrs[] = {
	&dev_attr_TermChar.attr,
	&dev_attr_TermCharEnabled.attr,
	&dev_attr_auto_abort.attr,
	NULL,
};

static struct attribute_group data_attr_grp = {
	.attrs = data_attrs,
};

static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
{
	struct device *dev;
	u8 *buffer;
	int rv;

	dev = &data->intf->dev;

	buffer = kmalloc(2, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	rv = usb_control_msg(data->usb_dev,
			     usb_rcvctrlpipe(data->usb_dev, 0),
			     USBTMC_REQUEST_INDICATOR_PULSE,
			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
			     0, 0, buffer, 0x01, USBTMC_TIMEOUT);

	if (rv < 0) {
		dev_err(dev, "usb_control_msg returned %d\n", rv);
		goto exit;
	}

	dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);

	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
		dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
		rv = -EPERM;
		goto exit;
	}
	rv = 0;

exit:
	kfree(buffer);
	return rv;
}

static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct usbtmc_device_data *data;
	int retval = -EBADRQC;

	data = file->private_data;
	mutex_lock(&data->io_mutex);
1042 1043 1044 1045
	if (data->zombie) {
		retval = -ENODEV;
		goto skip_io_on_zombie;
	}
1046 1047 1048 1049

	switch (cmd) {
	case USBTMC_IOCTL_CLEAR_OUT_HALT:
		retval = usbtmc_ioctl_clear_out_halt(data);
1050
		break;
1051 1052 1053

	case USBTMC_IOCTL_CLEAR_IN_HALT:
		retval = usbtmc_ioctl_clear_in_halt(data);
1054
		break;
1055 1056 1057

	case USBTMC_IOCTL_INDICATOR_PULSE:
		retval = usbtmc_ioctl_indicator_pulse(data);
1058
		break;
1059 1060 1061

	case USBTMC_IOCTL_CLEAR:
		retval = usbtmc_ioctl_clear(data);
1062
		break;
1063 1064 1065

	case USBTMC_IOCTL_ABORT_BULK_OUT:
		retval = usbtmc_ioctl_abort_bulk_out(data);
1066
		break;
1067 1068 1069

	case USBTMC_IOCTL_ABORT_BULK_IN:
		retval = usbtmc_ioctl_abort_bulk_in(data);
1070
		break;
1071 1072
	}

1073
skip_io_on_zombie:
1074 1075 1076 1077
	mutex_unlock(&data->io_mutex);
	return retval;
}

1078
static const struct file_operations fops = {
1079 1080 1081 1082 1083 1084
	.owner		= THIS_MODULE,
	.read		= usbtmc_read,
	.write		= usbtmc_write,
	.open		= usbtmc_open,
	.release	= usbtmc_release,
	.unlocked_ioctl	= usbtmc_ioctl,
1085
	.llseek		= default_llseek,
1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105
};

static struct usb_class_driver usbtmc_class = {
	.name =		"usbtmc%d",
	.fops =		&fops,
	.minor_base =	USBTMC_MINOR_BASE,
};


static int usbtmc_probe(struct usb_interface *intf,
			const struct usb_device_id *id)
{
	struct usbtmc_device_data *data;
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor *endpoint;
	int n;
	int retcode;

	dev_dbg(&intf->dev, "%s called\n", __func__);

1106
	data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL);
1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117
	if (!data) {
		dev_err(&intf->dev, "Unable to allocate kernel memory\n");
		return -ENOMEM;
	}

	data->intf = intf;
	data->id = id;
	data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
	usb_set_intfdata(intf, data);
	kref_init(&data->kref);
	mutex_init(&data->io_mutex);
1118
	data->zombie = 0;
1119

1120 1121 1122
	/* Determine if it is a Rigol or not */
	data->rigol_quirk = 0;
	dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
1123 1124
		le16_to_cpu(data->usb_dev->descriptor.idVendor),
		le16_to_cpu(data->usb_dev->descriptor.idProduct));
1125
	for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
1126 1127
		if ((usbtmc_id_quirk[n].idVendor == le16_to_cpu(data->usb_dev->descriptor.idVendor)) &&
		    (usbtmc_id_quirk[n].idProduct == le16_to_cpu(data->usb_dev->descriptor.idProduct))) {
1128 1129 1130 1131 1132 1133
			dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
			data->rigol_quirk = 1;
			break;
		}
	}

1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
	/* Initialize USBTMC bTag and other fields */
	data->bTag	= 1;
	data->TermCharEnabled = 0;
	data->TermChar = '\n';

	/* USBTMC devices have only one setting, so use that */
	iface_desc = data->intf->cur_altsetting;

	/* Find bulk in endpoint */
	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
		endpoint = &iface_desc->endpoint[n].desc;

		if (usb_endpoint_is_bulk_in(endpoint)) {
			data->bulk_in = endpoint->bEndpointAddress;
			dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
				data->bulk_in);
			break;
		}
	}

	/* Find bulk out endpoint */
	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
		endpoint = &iface_desc->endpoint[n].desc;

		if (usb_endpoint_is_bulk_out(endpoint)) {
			data->bulk_out = endpoint->bEndpointAddress;
			dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
				data->bulk_out);
			break;
		}
	}

	retcode = get_capabilities(data);
	if (retcode)
		dev_err(&intf->dev, "can't read capabilities\n");
	else
		retcode = sysfs_create_group(&intf->dev.kobj,
					     &capability_attr_grp);

	retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);

	retcode = usb_register_dev(intf, &usbtmc_class);
	if (retcode) {
		dev_err(&intf->dev, "Not able to get a minor"
			" (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
			retcode);
		goto error_register;
	}
	dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);

	return 0;

error_register:
	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
	kref_put(&data->kref, usbtmc_delete);
	return retcode;
}

static void usbtmc_disconnect(struct usb_interface *intf)
{
	struct usbtmc_device_data *data;

	dev_dbg(&intf->dev, "usbtmc_disconnect called\n");

	data = usb_get_intfdata(intf);
	usb_deregister_dev(intf, &usbtmc_class);
	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1203 1204 1205
	mutex_lock(&data->io_mutex);
	data->zombie = 1;
	mutex_unlock(&data->io_mutex);
1206 1207 1208
	kref_put(&data->kref, usbtmc_delete);
}

1209
static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1210 1211 1212 1213 1214
{
	/* this driver does not have pending URBs */
	return 0;
}

1215
static int usbtmc_resume(struct usb_interface *intf)
1216 1217 1218 1219
{
	return 0;
}

1220 1221 1222 1223
static struct usb_driver usbtmc_driver = {
	.name		= "usbtmc",
	.id_table	= usbtmc_devices,
	.probe		= usbtmc_probe,
1224 1225 1226
	.disconnect	= usbtmc_disconnect,
	.suspend	= usbtmc_suspend,
	.resume		= usbtmc_resume,
1227 1228
};

1229
module_usb_driver(usbtmc_driver);
1230 1231

MODULE_LICENSE("GPL");