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>
diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
index 76d7720..8c331f1 100644
--- a/drivers/usb/misc/Kconfig
+++ b/drivers/usb/misc/Kconfig
@@ -255,3 +255,15 @@
This driver is for generating specific traffic for Super Speed Link
Layer Test Device. Say Y only when you want to conduct USB Super Speed
Link Layer Test for host controllers.
+
+config USB_CHAOSKEY
+ tristate "ChaosKey random number generator driver support"
+ help
+ Say Y here if you want to connect an AltusMetrum ChaosKey to
+ your computer's USB port. The ChaosKey is a hardware random
+ number generator which hooks into the kernel entropy pool to
+ ensure a large supply of entropy for /dev/random and
+ /dev/urandom and also provides direct access via /dev/chaoskeyX
+
+ To compile this driver as a module, choose M here: the
+ module will be called chaoskey.