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. *OBSOLETE* 26 * @data_read: Read data from the RNG device. 27 * Returns the number of lower random bytes in "data". 28 * Must not be NULL. *OBSOLETE* 29 * @read: New API. drivers can fill up to max bytes of data 30 * into the buffer. The buffer is aligned for any type. 31 * @priv: Private data, for use by the RNG driver. 32 * @quality: Estimation of true entropy in RNG's bitstream 33 * (per mill). 34 */ 35 struct hwrng { 36 const char *name; 37 int (*init)(struct hwrng *rng); 38 void (*cleanup)(struct hwrng *rng); 39 int (*data_present)(struct hwrng *rng, int wait); 40 int (*data_read)(struct hwrng *rng, u32 *data); 41 int (*read)(struct hwrng *rng, void *data, size_t max, bool wait); 42 unsigned long priv; 43 unsigned short quality; 44 45 /* internal. */ 46 struct list_head list; 47 }; 48 49 /** Register a new Hardware Random Number Generator driver. */ 50 extern int hwrng_register(struct hwrng *rng); 51 /** Unregister a Hardware Random Number Generator driver. */ 52 extern void hwrng_unregister(struct hwrng *rng); 53 /** Feed random bits into the pool. */ 54 extern void add_hwgenerator_randomness(const char *buffer, size_t count, size_t entropy); 55 56 #endif /* LINUX_HWRANDOM_H_ */ 57