Add ioctls to enable and disable local controls on an instrument

These ioctls provide support for the USBTMC-USB488 control requests
for REN_CONTROL, GO_TO_LOCAL and LOCAL_LOCKOUT

Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 70 insertions, 0 deletions

diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 6edb21ca9989..419c72e10464 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -474,6 +474,61 @@ static int usbtmc488_ioctl_read_stb(struct usbtmc_device_data *data,
         return rv;
 }
 
+static int usbtmc488_ioctl_simple(struct usbtmc_device_data *data,
+                                void __user *arg, unsigned int cmd)
+{
+        struct device *dev = &data->intf->dev;
+        __u8 val;
+        u8 *buffer;
+        u16 wValue;
+        int rv;
+
+        if (!(data->usb488_caps & USBTMC488_CAPABILITY_SIMPLE))
+                return -EINVAL;
+
+        buffer = kmalloc(8, GFP_KERNEL);
+        if (!buffer)
+                return -ENOMEM;
+
+        if (cmd == USBTMC488_REQUEST_REN_CONTROL) {
+                rv = copy_from_user(&val, arg, sizeof(val));
+                if (rv) {
+                        rv = -EFAULT;
+                        goto exit;
+                }
+                wValue = val ? 1 : 0;
+        } else {
+                wValue = 0;
+        }
+
+        rv = usb_control_msg(data->usb_dev,
+                        usb_rcvctrlpipe(data->usb_dev, 0),
+                        cmd,
+                        USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+                        wValue,
+                        data->ifnum,
+                        buffer, 0x01, USBTMC_TIMEOUT);
+        if (rv < 0) {
+                dev_err(dev, "simple usb_control_msg failed %d\n", rv);
+                goto exit;
+        } else if (rv != 1) {
+                dev_warn(dev, "simple usb_control_msg returned %d\n", rv);
+                rv = -EIO;
+                goto exit;
+        }
+
+        if (buffer[0] != USBTMC_STATUS_SUCCESS) {
+                dev_err(dev, "simple control status returned %x\n", buffer[0]);
+                rv = -EIO;
+                goto exit;
+        }
+        rv = 0;
+
+ exit:
+        kfree(buffer);
+        return rv;
+}
+
 /*
  * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
  * @transfer_size: number of bytes to request from the device.
@@ -1183,6 +1238,21 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
         case USBTMC488_IOCTL_READ_STB:
                 retval = usbtmc488_ioctl_read_stb(data, (void __user *)arg);
                 break;
+
+        case USBTMC488_IOCTL_REN_CONTROL:
+                retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
+                                                USBTMC488_REQUEST_REN_CONTROL);
+                break;
+
+        case USBTMC488_IOCTL_GOTO_LOCAL:
+                retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
+                                                USBTMC488_REQUEST_GOTO_LOCAL);
+                break;
+
+        case USBTMC488_IOCTL_LOCAL_LOCKOUT:
+                retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
+                                                USBTMC488_REQUEST_LOCAL_LOCKOUT);
+                break;
         }
 
 skip_io_on_zombie: