diff options
| author | Dave Penkler <dpenkler@gmail.com> | 2020-12-15 16:56:20 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-28 15:50:30 +0100 |
| commit | d1d9defdc6d582119d29f5d88f810b72bb1837fa (patch) | |
| tree | f3dce4bbad4c77f09e8d3876602afd8f81171e86 /include/uapi/linux/usb | |
| parent | c9784e23c1020e63d6dba5e10ca8bf3d8b85c19c (diff) | |
USB: usbtmc: Add separate USBTMC_IOCTL_GET_SRQ_STB
This new ioctl only returns the status byte (STB) that was originally
sent by the device due to a service request (SRQ) condition.
This ioctl checks the srq_asserted bit of the associated file
descriptor. If set, the srq_asserted bit is reset and the cached
STB with original SRQ information is returned. Otherwise the ioctl
returns the error code ENOMSG.
This ioctl is useful to support non USBTMC-488 compliant devices.
Time sensitive applications can read the cached STB without incurring
the cost of an urb transaction over the bus.
Tested-by: Jian-Wei Wu <jian-wei_wu@keysight.com>
Reviewed-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Link: https://lore.kernel.org/r/20201215155621.9592-4-dpenkler@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/uapi/linux/usb')
| -rw-r--r-- | include/uapi/linux/usb/tmc.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/uapi/linux/usb/tmc.h b/include/uapi/linux/usb/tmc.h index 1e7878fe591f..d791cc58a7f0 100644 --- a/include/uapi/linux/usb/tmc.h +++ b/include/uapi/linux/usb/tmc.h @@ -103,6 +103,7 @@ struct usbtmc_message { #define USBTMC_IOCTL_AUTO_ABORT _IOW(USBTMC_IOC_NR, 25, __u8) #define USBTMC_IOCTL_GET_STB _IOR(USBTMC_IOC_NR, 26, __u8) +#define USBTMC_IOCTL_GET_SRQ_STB _IOR(USBTMC_IOC_NR, 27, __u8) /* Cancel and cleanup asynchronous calls */ #define USBTMC_IOCTL_CANCEL_IO _IO(USBTMC_IOC_NR, 35) |