tree d54303288c4261218e78587c48f9e376d8118f77
parent 1fcefbdf06708a5811ffa8acc949714aee60ae13
author Keith Packard <keithp@keithp.com> 1426822609 -0700
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1427363231 +0100

usb: Add driver for Altus Metrum ChaosKey device (v2)

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>