Add USBTMC_IOCTL_CTRL_REQUEST to send arbitrary requests on the
control pipe. Used by specific applications of IVI Foundation,
Inc. to implement VISA API functions: viUsbControlIn/Out.
The maximum length of control request is set to 4k.
This ioctl does not support compatibility for 32 bit
applications running on 64 bit systems. However all other
convenient ioctls of the USBTMC driver can still be used in 32
bit applications as well. Note that 32 bit applications running
on 32 bit target systems are not affected by this limitation.
Signed-off-by: Guido Kiener
Reviewed-by: Steve Bayless
---
drivers/usb/class/usbtmc.c | 69
include/uapi/linux/usb/tmc.h | 15
2 files changed, 84 insertions(+)
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 83ffa5a14c3d..7e69bd05c631 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -5,6 +5,7 @@
* Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
* Copyright (C) 2008 Novell, Inc.
* Copyright (C) 2008 Greg Kroah-Hartman
+ * Copyright (C) 2018 IVI Foundation, Inc.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -36,6 +37,9 @@
/* Default USB timeout (in milliseconds) */
#define USBTMC_TIMEOUT 5000
+/* I/O buffer size used in generic read/write functions */
+#define USBTMC_BUFSIZE (4096)
+
/*
* 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
@@ -1250,6 +1254,67 @@ static int usbtmc_ioctl_indicator_pulse(struct
usbtmc_device_data *data)
return rv;
}
+static int usbtmc_ioctl_request(struct usbtmc_device_data *data,
+ void __user *arg)
+{
+ struct device *dev = >intf->dev;
+ struct usbtmc_ctrlrequest request;
+ u8 *buffer = NULL;
+ int rv;
+ unsigned long res;
+
+ res = copy_from_user(, arg, sizeof(struct usbtmc_ctrlrequest));
+ if (res)
+ return -EFAULT;
+
+ buffer = kmalloc(request.req.wLength, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ if (request.req.wLength > USBTMC_BUFSIZE)
+ return -EMSGSIZE;
+
+ if (request.req.wLength) {
+ buffer = kmalloc(request.req.wLength, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ if ((request.req.bRequestType & USB_DIR_IN) == 0) {
+ /* Send control data to device */
+ res = copy_from_user(buffer, request.data,
+request.req.wLength);
+ if (res) {
+ rv = -EFAULT;
+ goto exit;
+ }
+ }
+ }
+
+ rv = usb_control_msg(data->usb_dev,
+ usb_rcvctrlpipe(data->usb_dev, 0),
+ request.req.bRequest,
+ request.req.bRequestType,
+ request.req.wValue,
+ request.req.wIndex,
+ buffer, request.req.wLength, USB_CTRL_GET_TIMEOUT);
+
+ if (rv < 0) {
+ dev_err(dev, "%s failed %d\n", __func__, rv);
+ goto exit;
+ }
+
+ if (rv && (request.req.bRequestType & USB_DIR_IN)) {
+ /* Read control data from device */
+ res = copy_to_user(request.data, buffer, rv);
+ if (res)
+ rv = -EFAULT;
+ }
+
+ exit:
+ kfree(buffer);
+ return rv;
+}
+
/*
* Get the usb timeout value
*/
@@ -1366,6 +1431,10 @@ static long usbtmc_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
retval = usbtmc_ioctl_abort_bulk_in(data);
break;
+ case USBTMC_IOCTL_CTRL_REQUEST:
+ retval = usbtmc_ioctl_request(data, (void __user *)arg);
+ break;
+
case USBTMC_IOCTL_GET_TIMEOUT:
retval = usbtmc_ioctl_get_timeout(file_data,
(void __user *)arg);
diff --git a/include/uapi/linux/usb/tmc.h b/include/uapi/linux/usb/tmc.h
index 729af2f861a4..5e12928ed1e5 100644
--- a/include/uapi/linux/usb/tmc.h
+++ b/include/uapi/linux/usb/tmc.h
@@ -4,6 +4,7 @@
* Copyright (C) 2008 Novell, Inc.
* Copyright (C) 2008 Greg Kroah-Hartman
* Copyright (C) 2015 Dave Penkler
+ * Copyright (C) 2018 IVI Foundation, Inc.
*
* This file holds USB constants defined by the USB Device Class
* and USB488 Subclass Definitions for Test and Measurement devices
@@ -40,6 +41,19 @@
#define USBTMC488_REQUEST_GOTO_LOCAL 161
#define USBTMC488_REQUEST_LOCAL_LOCKOUT162
+struct usbtmc_request {
+ __u8 bRequestType;
+ __u8 bRequest;
+ __u16 wValue;
+ __u16 wIndex;
+ __u16 wLength;
+}
