>    drivers/usb/misc/chaoskey.c: In function 'chaoskey_read':
> >> drivers/usb/misc/chaoskey.c:412:3: error: implicit declaration of function 'copy_to_user'
> >> [-Werror=implicit-function-declaration]
>       remain = copy_to_user(buffer, dev->buf + dev->used, this_time);

I was unable to reproduce this locally, but added an explicit

	#include <linux/uaccess.h>

which should ensure the definition on all architectures.

> sparse warnings: (new ones prefixed by >>)
>
> >> drivers/usb/misc/chaoskey.c:117:30: sparse: incorrect type in assignment (different base types)
>    drivers/usb/misc/chaoskey.c:117:30:    expected int [signed] size
>    drivers/usb/misc/chaoskey.c:117:30:    got restricted __le16 [usertype] wMaxPacketSize

Switched the code to using the USB descriptor accessor functions.

Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This is a hardware random number generator. The driver provides both a
/dev/chaoskeyX entry and hooks the entropy source up to the kernel
hwrng interface. More information about the device can be found at
http://chaoskey.org

The USB ID for ChaosKey was allocated from the OpenMoko USB vendor
space and is visible as 'USBtrng' here:

http://wiki.openmoko.org/wiki/USB_Product_IDs

v2: Respond to review from Oliver Neukum <oneukum@suse.de>

 * Delete extensive debug infrastructure and replace it with calls to
   dev_dbg.

 * Allocate I/O buffer separately from device structure to obey
   requirements for non-coherant architectures.

 * Initialize mutexes before registering device to ensure that open
   cannot be invoked before the device is ready to proceed.

 * Return number of bytes read instead of -EINTR when partial read
   operation is aborted due to a signal.

 * Make sure device mutex is unlocked in read error paths.

 * Add MAINTAINERS entry for the driver

Signed-off-by: Keith Packard <keithp@keithp.com>
Cc: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>