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/completion.h> 16 #include <linux/types.h> 17 #include <linux/list.h> 18 #include <linux/kref.h> 19 20 /** 21 * struct hwrng - Hardware Random Number Generator driver 22 * @name: Unique RNG name. 23 * @init: Initialization callback (can be NULL). 24 * @cleanup: Cleanup callback (can be NULL). 25 * @data_present: Callback to determine if data is available 26 * on the RNG. If NULL, it is assumed that 27 * there is always data available. *OBSOLETE* 28 * @data_read: Read data from the RNG device. 29 * Returns the number of lower random bytes in "data". 30 * Must not be NULL. *OBSOLETE* 31 * @read: New API. drivers can fill up to max bytes of data 32 * into the buffer. The buffer is aligned for any type. 33 * @priv: Private data, for use by the RNG driver. 34 * @quality: Estimation of true entropy in RNG's bitstream 35 * (per mill). 36 */ 37 struct hwrng { 38 const char *name; 39 int (*init)(struct hwrng *rng); 40 void (*cleanup)(struct hwrng *rng); 41 int (*data_present)(struct hwrng *rng, int wait); 42 int (*data_read)(struct hwrng *rng, u32 *data); 43 int (*read)(struct hwrng *rng, void *data, size_t max, bool wait); 44 unsigned long priv; 45 unsigned short quality; 46 47 /* internal. */ 48 struct list_head list; 49 struct kref ref; 50 struct completion cleanup_done; 51 }; 52 53 struct device; 54 55 /** Register a new Hardware Random Number Generator driver. */ 56 extern int hwrng_register(struct hwrng *rng); 57 extern int devm_hwrng_register(struct device *dev, struct hwrng *rng); 58 /** Unregister a Hardware Random Number Generator driver. */ 59 extern void hwrng_unregister(struct hwrng *rng); 60 extern void devm_hwrng_unregister(struct device *dve, struct hwrng *rng); 61 /** Feed random bits into the pool. */ 62 extern void add_hwgenerator_randomness(const char *buffer, size_t count, size_t entropy); 63 64 #endif /* LINUX_HWRANDOM_H_ */ 65