kernel-ark/include/linux/hw_random.h
Rafael J. Wysocki a41e3dc406 HWRNG: add possibility to remove hwrng devices during suspend/resume
Make it possible to unregister a Hardware Random Number Generator
device object in a safe way during a suspend/resume cycle.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Michael Buesch <mb@bu3sch.de>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:23 -08:00

59 lines
1.7 KiB
C

/*
Hardware Random Number Generator
Please read Documentation/hw_random.txt for details on use.
----------------------------------------------------------
This software may be used and distributed according to the terms
of the GNU General Public License, incorporated herein by reference.
*/
#ifndef LINUX_HWRANDOM_H_
#define LINUX_HWRANDOM_H_
#ifdef __KERNEL__
#include <linux/types.h>
#include <linux/list.h>
/**
* struct hwrng - Hardware Random Number Generator driver
* @name: Unique RNG name.
* @init: Initialization callback (can be NULL).
* @cleanup: Cleanup callback (can be NULL).
* @data_present: Callback to determine if data is available
* on the RNG. If NULL, it is assumed that
* there is always data available.
* @data_read: Read data from the RNG device.
* Returns the number of lower random bytes in "data".
* Must not be NULL.
* @priv: Private data, for use by the RNG driver.
*/
struct hwrng {
const char *name;
int (*init)(struct hwrng *rng);
void (*cleanup)(struct hwrng *rng);
int (*data_present)(struct hwrng *rng, int wait);
int (*data_read)(struct hwrng *rng, u32 *data);
unsigned long priv;
/* internal. */
struct list_head list;
};
/** Register a new Hardware Random Number Generator driver. */
extern int hwrng_register(struct hwrng *rng);
/** Unregister a Hardware Random Number Generator driver. */
extern void __hwrng_unregister(struct hwrng *rng, bool suspended);
static inline void hwrng_unregister(struct hwrng *rng)
{
__hwrng_unregister(rng, false);
}
static inline void hwrng_unregister_suspended(struct hwrng *rng)
{
__hwrng_unregister(rng, true);
}
#endif /* __KERNEL__ */
#endif /* LINUX_HWRANDOM_H_ */