On Sun, Jan 24, 2016 at 08:42:54PM -0800, Greg KH wrote:
> On Sun, Nov 29, 2015 at 01:35:51PM +0100, Dave Penkler wrote:
> > 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@xxxxxxxxx>
> > ---
> > 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 3b85ef5..3a3264c 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 */
> > @@ -992,6 +995,7 @@ 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:
> > @@ -1167,6 +1171,14 @@ 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@xxxxxxx>
> > + * Copyright (C) 2015 Dave Penkler <dpenkler@xxxxxxxxx>
> > *
> > * 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)
>
> Shouldn't there be a data structure mentioned here that gets passed back
> to userspace? And are you sure the direction is correct as well?
>
Oops, it should read:
#define USBTMC488_IOCTL_GET_CAPS _IOR(USBTMC_IOC_NR, 17, unsigned char)
Thanks,
-dave
> thanks,
>
> greg k-h
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