[PATCH v5 4/5] Add ioctl to retrieve USBTMC-USB488 capabilities

Dave Penkler
2015-11-18T08:38:34Z

This is a convenience function to obtain an instrument's
capabilities from its file descriptor without having to access sysfs
from the user program.

Signed-off-by: Dave Penkler <dpenkler@gmail.com>
---
drivers/usb/class/usbtmc.c | 12 ++++++++++++
include/uapi/linux/usb/tmc.h | 21 ++++++++++++++++++---
2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 6294a3c..2358991 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -102,6 +102,9 @@ struct usbtmc_device_data {
u16 iin_wMaxPacketSize;
atomic_t srq_asserted;

+ /* coalesced usb488_caps from usbtmc_dev_capabilities */
+ u8 usb488_caps;
+
u8 rigol_quirk;

/* attributes from the USB TMC spec for this device */
@@ -995,6 +998,7 @@ static int get_capabilities(struct usbtmc_device_data *data)
data->capabilities.device_capabilities = buffer[5];
data->capabilities.usb488_interface_capabilities = buffer[14];
data->capabilities.usb488_device_capabilities = buffer[15];
+ data->usb488_caps = (buffer[14] & 0x07) | ((buffer[15] & 0x0f) << 4);
rv = 0;

err_out:
@@ -1170,6 +1174,14 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
retval = usbtmc_ioctl_abort_bulk_in(data);
break;

+ case USBTMC488_IOCTL_GET_CAPS:
+ retval = copy_to_user((void __user *)arg,
+ &data->usb488_caps,
+ sizeof(data->usb488_caps));
+ if (retval)
+ retval = -EFAULT;
+ break;
+
case USBTMC488_IOCTL_READ_STB:
retval = usbtmc488_ioctl_read_stb(data, arg);
break;
diff --git a/include/uapi/linux/usb/tmc.h b/include/uapi/linux/usb/tmc.h
index 7e5ced8..1dc3af1 100644
--- a/include/uapi/linux/usb/tmc.h
+++ b/include/uapi/linux/usb/tmc.h
@@ -2,12 +2,14 @@
* Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
* Copyright (C) 2008 Novell, Inc.
* Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (C) 2015 Dave Penkler <dpenkler@gmail.com>
*
* This file holds USB constants defined by the USB Device Class
- * Definition for Test and Measurement devices published by the USB-IF.
+ * and USB488 Subclass Definitions for Test and Measurement devices
+ * published by the USB-IF.
*
- * It also has the ioctl definitions for the usbtmc kernel driver that
- * userspace needs to know about.
+ * It also has the ioctl and capability definitions for the
+ * usbtmc kernel driver that userspace needs to know about.
*/

#ifndef __LINUX_USB_TMC_H
@@ -40,6 +42,19 @@
#define USBTMC_IOCTL_ABORT_BULK_IN _IO(USBTMC_IOC_NR, 4)
#define USBTMC_IOCTL_CLEAR_OUT_HALT _IO(USBTMC_IOC_NR, 6)
#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)

+/* Driver encoded usb488 capabilities */
+#define USBTMC488_CAPABILITY_TRIGGER 1
+#define USBTMC488_CAPABILITY_SIMPLE 2
+#define USBTMC488_CAPABILITY_REN_CONTROL 2
+#define USBTMC488_CAPABILITY_GOTO_LOCAL 2
+#define USBTMC488_CAPABILITY_LOCAL_LOCKOUT 2
+#define USBTMC488_CAPABILITY_488_DOT_2 4
+#define USBTMC488_CAPABILITY_DT1 16
+#define USBTMC488_CAPABILITY_RL1 32
+#define USBTMC488_CAPABILITY_SR1 64
+#define USBTMC488_CAPABILITY_FULL_SCPI 128
+
#endif
--
2.5.1