1 /* 2 Hardware Random Number Generator 3 4 Please read Documentation/hw_random.txt for details on use. 5 6 ---------------------------------------------------------- 7 This software may be used and distributed according to the terms 8 of the GNU General Public License, incorporated herein by reference. 9 10 */ 11 12 #ifndef LINUX_HWRANDOM_H_ 13 #define LINUX_HWRANDOM_H_ 14 15 #include <linux/types.h> 16 #include <linux/list.h> 17 18 /** 19 * struct hwrng - Hardware Random Number Generator driver 20 * @name: Unique RNG name. 21 * @init: Initialization callback (can be NULL). 22 * @cleanup: Cleanup callback (can be NULL). 23 * @data_present: Callback to determine if data is available 24 * on the RNG. If NULL, it is assumed that 25 * there is always data available. 26 * @data_read: Read data from the RNG device. 27 * Returns the number of lower random bytes in "data". 28 * Must not be NULL. 29 * @priv: Private data, for use by the RNG driver. 30 */ 31 struct hwrng { 32 const char *name; 33 int (*init)(struct hwrng *rng); 34 void (*cleanup)(struct hwrng *rng); 35 int (*data_present)(struct hwrng *rng, int wait); 36 int (*data_read)(struct hwrng *rng, u32 *data); 37 unsigned long priv; 38 39 /* internal. */ 40 struct list_head list; 41 }; 42 43 /** Register a new Hardware Random Number Generator driver. */ 44 extern int hwrng_register(struct hwrng *rng); 45 /** Unregister a Hardware Random Number Generator driver. */ 46 extern void hwrng_unregister(struct hwrng *rng); 47 48 #endif /* LINUX_HWRANDOM_H_ */ 49