[PATCH v5 5/5] Add ioctls to enable and disable local controls on an instrument

Dave Penkler
2015-11-18T08:38:49Z

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>
---
drivers/usb/class/usbtmc.c | 71 ++++++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/usb/tmc.h | 6 ++++
2 files changed, 77 insertions(+)

diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 2358991..d416a5f 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -476,6 +476,62 @@ static int usbtmc488_ioctl_read_stb(struct usbtmc_device_data *data,
return rv;
}

+static int usbtmc488_ioctl_simple(struct usbtmc_device_data *data,
+ unsigned long arg,
+ unsigned int cmd)
+{
+ u8 *buffer;
+ struct device *dev = &data->intf->dev;
+ int rv;
+ unsigned int val;
+ u16 wValue;
+
+ 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, (void __user *)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);
+ 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.
@@ -1185,6 +1241,21 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case USBTMC488_IOCTL_READ_STB:
retval = usbtmc488_ioctl_read_stb(data, arg);
break;
+
+ case USBTMC488_IOCTL_REN_CONTROL:
+ retval = usbtmc488_ioctl_simple(data, arg,
+ USBTMC488_REQUEST_REN_CONTROL);
+ break;
+
+ case USBTMC488_IOCTL_GOTO_LOCAL:
+ retval = usbtmc488_ioctl_simple(data, arg,
+ USBTMC488_REQUEST_GOTO_LOCAL);
+ break;
+
+ case USBTMC488_IOCTL_LOCAL_LOCKOUT:
+ retval = usbtmc488_ioctl_simple(data, arg,
+ USBTMC488_REQUEST_LOCAL_LOCKOUT);
+ break;
}

skip_io_on_zombie:
diff --git a/include/uapi/linux/usb/tmc.h b/include/uapi/linux/usb/tmc.h
index 1dc3af1..0d852c9 100644
--- a/include/uapi/linux/usb/tmc.h
+++ b/include/uapi/linux/usb/tmc.h
@@ -33,6 +33,9 @@
#define USBTMC_REQUEST_GET_CAPABILITIES 7
#define USBTMC_REQUEST_INDICATOR_PULSE 64
#define USBTMC488_REQUEST_READ_STATUS_BYTE 128
+#define USBTMC488_REQUEST_REN_CONTROL 160
+#define USBTMC488_REQUEST_GOTO_LOCAL 161
+#define USBTMC488_REQUEST_LOCAL_LOCKOUT 162

/* Request values for USBTMC driver's ioctl entry point */
#define USBTMC_IOC_NR 91
@@ -44,6 +47,9 @@
#define USBTMC_IOCTL_CLEAR_IN_HALT _IO(USBTMC_IOC_NR, 7)
#define USBTMC488_IOCTL_GET_CAPS _IO(USBTMC_IOC_NR, 17)
#define USBTMC488_IOCTL_READ_STB _IOR(USBTMC_IOC_NR, 18, unsigned char)
+#define USBTMC488_IOCTL_REN_CONTROL _IOW(USBTMC_IOC_NR, 19, unsigned char)
+#define USBTMC488_IOCTL_GOTO_LOCAL _IO(USBTMC_IOC_NR, 20)
+#define USBTMC488_IOCTL_LOCAL_LOCKOUT _IO(USBTMC_IOC_NR, 21)

/* Driver encoded usb488 capabilities */
#define USBTMC488_CAPABILITY_TRIGGER 1
--
2.5.1