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>
4 files changed
