From 658f24f4523e41cda6a389c38b763f4c0cad6fbc Mon Sep 17 00:00:00 2001 From: Guido Kiener Date: Wed, 12 Sep 2018 10:50:51 +0200 Subject: usb: usbtmc: Add ioctl for generic requests on control 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/usbtmc.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) (limited to 'drivers/usb') 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 @@ exit: return rv; } +static int usbtmc_ioctl_request(struct usbtmc_device_data *data, + void __user *arg) +{ + struct device *dev = &data->intf->dev; + struct usbtmc_ctrlrequest request; + u8 *buffer = NULL; + int rv; + unsigned long res; + + res = copy_from_user(&request, 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); -- cgit v1.2.3