USB: add USB test and measurement class driver
This driver was originaly written by Stefan Kopp, but massively
reworked by Greg for submission.
Thanks to Felipe Balbi <me@felipebalbi.com> for lots of work in cleaning
up this driver.
Thanks to Oliver Neukum <oliver@neukum.org> for reviewing previous
versions and pointing out problems.
Cc: Stefan Kopp <stefan_kopp@agilent.com>
Cc: Marcel Janssen <korgull@home.nl>
Cc: Felipe Balbi <me@felipebalbi.com>
Cc: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/class/Kconfig b/drivers/usb/class/Kconfig
index 66f17ed..2519e32 100644
--- a/drivers/usb/class/Kconfig
+++ b/drivers/usb/class/Kconfig
@@ -40,3 +40,13 @@
To compile this driver as a module, choose M here: the
module will be called cdc-wdm.
+config USB_TMC
+ tristate "USB Test and Measurement Class support"
+ depends on USB
+ help
+ Say Y here if you want to connect a USB device that follows
+ the USB.org specification for USB Test and Measurement devices
+ to your computer's USB port.
+
+ To compile this driver as a module, choose M here: the
+ module will be called usbtmc.
diff --git a/drivers/usb/class/Makefile b/drivers/usb/class/Makefile
index 535d59a..32e8527 100644
--- a/drivers/usb/class/Makefile
+++ b/drivers/usb/class/Makefile
@@ -6,3 +6,4 @@
obj-$(CONFIG_USB_ACM) += cdc-acm.o
obj-$(CONFIG_USB_PRINTER) += usblp.o
obj-$(CONFIG_USB_WDM) += cdc-wdm.o
+obj-$(CONFIG_USB_TMC) += usbtmc.o
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
new file mode 100644
index 0000000..543811f
--- /dev/null
+++ b/drivers/usb/class/usbtmc.c
@@ -0,0 +1,1087 @@
+/**
+ * drivers/usb/class/usbtmc.c - USB Test & Measurment class driver
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/kref.h>
+#include <linux/mutex.h>
+#include <linux/usb.h>
+#include <linux/usb/tmc.h>
+
+
+#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) */
+#define USBTMC_TIMEOUT 10
+
+/*
+ * 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
+
+static struct usb_device_id usbtmc_devices[] = {
+ { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
+ { 0, } /* terminating entry */
+};
+
+/*
+ * This structure is the capabilities for the device
+ * See section 4.2.1.8 of the USBTMC specification for details.
+ */
+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 */
+
+ /* attributes from the USB TMC spec for this device */
+ u8 TermChar;
+ bool TermCharEnabled;
+ bool auto_abort;
+
+ 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)
+
+/* 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);
+ kfree(data);
+}
+
+static int usbtmc_open(struct inode *inode, struct file *filp)
+{
+ struct usb_interface *intf;
+ struct usbtmc_device_data *data;
+ int retval = -ENODEV;
+
+ intf = usb_find_interface(&usbtmc_driver, iminor(inode));
+ if (!intf) {
+ printk(KERN_ERR KBUILD_MODNAME
+ ": can not find device for minor %d", iminor(inode));
+ goto exit;
+ }
+
+ data = usb_get_intfdata(intf);
+ kref_get(&data->kref);
+
+ /* Store pointer in file structure's private data field */
+ filp->private_data = data;
+
+exit:
+ 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)
+{
+ char *buffer;
+ 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)
+ max_size = le16_to_cpu(current_setting->endpoint[n].
+ desc.wMaxPacketSize);
+
+ 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;
+ }
+ } 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_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:
+ rv = usb_control_msg(data->usb_dev,
+ usb_sndctrlpipe(data->usb_dev, 0),
+ USB_REQ_CLEAR_FEATURE,
+ USB_DIR_OUT | USB_TYPE_STANDARD |
+ USB_RECIP_ENDPOINT,
+ USB_ENDPOINT_HALT, data->bulk_out, buffer,
+ 0, USBTMC_TIMEOUT);
+
+ if (rv < 0) {
+ dev_err(dev, "usb_control_msg returned %d\n", rv);
+ goto exit;
+ }
+ rv = 0;
+
+exit:
+ kfree(buffer);
+ return rv;
+}
+
+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;
+ unsigned long int n_characters;
+ u8 *buffer;
+ int actual;
+ int done;
+ int remaining;
+ int retval;
+ int this_part;
+
+ /* 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);
+
+ remaining = count;
+ done = 0;
+
+ while (remaining > 0) {
+ if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
+ this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
+ else
+ this_part = remaining;
+
+ /* Setup IO buffer for DEV_DEP_MSG_IN message
+ * Refer to class specs for details
+ */
+ buffer[0] = 2;
+ buffer[1] = data->bTag;
+ buffer[2] = ~(data->bTag);
+ buffer[3] = 0; /* Reserved */
+ buffer[4] = (this_part - 12 - 3) & 255;
+ buffer[5] = ((this_part - 12 - 3) >> 8) & 255;
+ buffer[6] = ((this_part - 12 - 3) >> 16) & 255;
+ buffer[7] = ((this_part - 12 - 3) >> 24) & 255;
+ 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, 12, &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)
+ (data->bTag)++;
+
+ if (retval < 0) {
+ dev_err(dev, "usb_bulk_msg returned %d\n", retval);
+ if (data->auto_abort)
+ usbtmc_ioctl_abort_bulk_out(data);
+ goto exit;
+ }
+
+ /* 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);
+
+ /* Store bTag (in case we need to abort) */
+ data->bTag_last_read = data->bTag;
+
+ if (retval < 0) {
+ dev_err(dev, "Unable to read data, error %d\n", retval);
+ if (data->auto_abort)
+ usbtmc_ioctl_abort_bulk_in(data);
+ goto exit;
+ }
+
+ /* How many characters did the instrument send? */
+ n_characters = buffer[4] +
+ (buffer[5] << 8) +
+ (buffer[6] << 16) +
+ (buffer[7] << 24);
+
+ /* Copy buffer to user space */
+ if (copy_to_user(buf + done, &buffer[12], n_characters)) {
+ /* There must have been an addressing problem */
+ retval = -EFAULT;
+ goto exit;
+ }
+
+ done += n_characters;
+ if (n_characters < USBTMC_SIZE_IOBUFFER)
+ remaining = 0;
+ }
+
+ /* 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 n;
+ 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);
+
+ remaining = count;
+ done = 0;
+
+ while (remaining > 0) {
+ if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
+ this_part = USBTMC_SIZE_IOBUFFER - 12;
+ 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;
+ buffer[2] = ~(data->bTag);
+ buffer[3] = 0; /* Reserved */
+ buffer[4] = this_part & 255;
+ buffer[5] = (this_part >> 8) & 255;
+ buffer[6] = (this_part >> 16) & 255;
+ buffer[7] = (this_part >> 24) & 255;
+ /* buffer[8] is set above... */
+ buffer[9] = 0; /* Reserved */
+ buffer[10] = 0; /* Reserved */
+ buffer[11] = 0; /* Reserved */
+
+ if (copy_from_user(&buffer[12], buf + done, this_part)) {
+ retval = -EFAULT;
+ goto exit;
+ }
+
+ n_bytes = 12 + this_part;
+ if (this_part % 4)
+ n_bytes += 4 - this_part % 4;
+ for (n = 12 + this_part; n < n_bytes; n++)
+ buffer[n] = 0;
+
+ retval = usb_bulk_msg(data->usb_dev,
+ usb_sndbulkpipe(data->usb_dev,
+ data->bulk_out),
+ buffer, n_bytes, &actual, USBTMC_TIMEOUT);
+
+ 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 = ¤t_setting->endpoint[n].desc;
+ if (desc->bEndpointAddress == data->bulk_in)
+ max_size = le16_to_cpu(desc->wMaxPacketSize);
+ }
+
+ 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:
+
+ rv = usb_control_msg(data->usb_dev,
+ usb_sndctrlpipe(data->usb_dev, 0),
+ USB_REQ_CLEAR_FEATURE,
+ USB_DIR_OUT | USB_TYPE_STANDARD |
+ USB_RECIP_ENDPOINT,
+ USB_ENDPOINT_HALT,
+ data->bulk_out, buffer, 0,
+ USBTMC_TIMEOUT);
+ 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)
+{
+ u8 *buffer;
+ int rv;
+
+ buffer = kmalloc(2, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ rv = usb_control_msg(data->usb_dev,
+ usb_sndctrlpipe(data->usb_dev, 0),
+ USB_REQ_CLEAR_FEATURE,
+ USB_DIR_OUT | USB_TYPE_STANDARD |
+ USB_RECIP_ENDPOINT,
+ USB_ENDPOINT_HALT, data->bulk_out,
+ buffer, 0, USBTMC_TIMEOUT);
+
+ if (rv < 0) {
+ dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
+ rv);
+ goto exit;
+ }
+ rv = 0;
+
+exit:
+ kfree(buffer);
+ return rv;
+}
+
+static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
+{
+ u8 *buffer;
+ int rv;
+
+ buffer = kmalloc(2, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ rv = usb_control_msg(data->usb_dev, usb_sndctrlpipe(data->usb_dev, 0),
+ USB_REQ_CLEAR_FEATURE,
+ USB_DIR_OUT | USB_TYPE_STANDARD |
+ USB_RECIP_ENDPOINT,
+ USB_ENDPOINT_HALT, data->bulk_in, buffer, 0,
+ USBTMC_TIMEOUT);
+
+ if (rv < 0) {
+ dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
+ rv);
+ goto exit;
+ }
+ rv = 0;
+
+exit:
+ kfree(buffer);
+ return rv;
+}
+
+static int get_capabilities(struct usbtmc_device_data *data)
+{
+ struct device *dev = &data->usb_dev->dev;
+ char *buffer;
+ int rv;
+
+ 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);
+ return rv;
+ }
+
+ dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
+ 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]);
+ if (buffer[0] != USBTMC_STATUS_SUCCESS) {
+ dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
+ return -EPERM;
+ }
+
+ 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];
+
+ kfree(buffer);
+ return 0;
+}
+
+#define capability_attribute(name) \
+static ssize_t show_##name(struct device *dev, \
+ 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); \
+} \
+static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
+
+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,
+};
+
+static ssize_t show_TermChar(struct device *dev,
+ 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);
+}
+
+static ssize_t store_TermChar(struct device *dev,
+ 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;
+}
+static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
+
+#define data_attribute(name) \
+static ssize_t show_##name(struct device *dev, \
+ 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); \
+} \
+static ssize_t store_##name(struct device *dev, \
+ 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; \
+} \
+static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
+
+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);
+
+ switch (cmd) {
+ case USBTMC_IOCTL_CLEAR_OUT_HALT:
+ retval = usbtmc_ioctl_clear_out_halt(data);
+
+ case USBTMC_IOCTL_CLEAR_IN_HALT:
+ retval = usbtmc_ioctl_clear_in_halt(data);
+
+ case USBTMC_IOCTL_INDICATOR_PULSE:
+ retval = usbtmc_ioctl_indicator_pulse(data);
+
+ case USBTMC_IOCTL_CLEAR:
+ retval = usbtmc_ioctl_clear(data);
+
+ case USBTMC_IOCTL_ABORT_BULK_OUT:
+ retval = usbtmc_ioctl_abort_bulk_out(data);
+
+ case USBTMC_IOCTL_ABORT_BULK_IN:
+ retval = usbtmc_ioctl_abort_bulk_in(data);
+ }
+
+ mutex_unlock(&data->io_mutex);
+ return retval;
+}
+
+static struct file_operations fops = {
+ .owner = THIS_MODULE,
+ .read = usbtmc_read,
+ .write = usbtmc_write,
+ .open = usbtmc_open,
+ .release = usbtmc_release,
+ .unlocked_ioctl = usbtmc_ioctl,
+};
+
+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__);
+
+ data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
+ 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);
+
+ /* 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);
+ kref_put(&data->kref, usbtmc_delete);
+}
+
+static struct usb_driver usbtmc_driver = {
+ .name = "usbtmc",
+ .id_table = usbtmc_devices,
+ .probe = usbtmc_probe,
+ .disconnect = usbtmc_disconnect
+};
+
+static int __init usbtmc_init(void)
+{
+ int retcode;
+
+ retcode = usb_register(&usbtmc_driver);
+ if (retcode)
+ printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
+ return retcode;
+}
+module_init(usbtmc_init);
+
+static void __exit usbtmc_exit(void)
+{
+ usb_deregister(&usbtmc_driver);
+}
+module_exit(usbtmc_exit);
+
+MODULE_LICENSE("GPL");