1844dd05fSMichael Buesch /* 2844dd05fSMichael Buesch Hardware Random Number Generator 3844dd05fSMichael Buesch 44f4cfa6cSMauro Carvalho Chehab Please read Documentation/admin-guide/hw_random.rst for details on use. 5844dd05fSMichael Buesch 6844dd05fSMichael Buesch ---------------------------------------------------------- 7844dd05fSMichael Buesch This software may be used and distributed according to the terms 8844dd05fSMichael Buesch of the GNU General Public License, incorporated herein by reference. 9844dd05fSMichael Buesch 10844dd05fSMichael Buesch */ 11844dd05fSMichael Buesch 12844dd05fSMichael Buesch #ifndef LINUX_HWRANDOM_H_ 13844dd05fSMichael Buesch #define LINUX_HWRANDOM_H_ 14844dd05fSMichael Buesch 1577584ee5SHerbert Xu #include <linux/completion.h> 163a2c0ba5SRusty Russell #include <linux/kref.h> 17*4604b388SAndy Shevchenko #include <linux/types.h> 18844dd05fSMichael Buesch 19844dd05fSMichael Buesch /** 20844dd05fSMichael Buesch * struct hwrng - Hardware Random Number Generator driver 21844dd05fSMichael Buesch * @name: Unique RNG name. 22844dd05fSMichael Buesch * @init: Initialization callback (can be NULL). 23844dd05fSMichael Buesch * @cleanup: Cleanup callback (can be NULL). 24844dd05fSMichael Buesch * @data_present: Callback to determine if data is available 25844dd05fSMichael Buesch * on the RNG. If NULL, it is assumed that 269996508bSIan Molton * there is always data available. *OBSOLETE* 27844dd05fSMichael Buesch * @data_read: Read data from the RNG device. 28844dd05fSMichael Buesch * Returns the number of lower random bytes in "data". 29988acec9SSasha Levin * Must not be NULL. *OBSOLETE* 309996508bSIan Molton * @read: New API. drivers can fill up to max bytes of data 31ed0bd721SDaniel Thompson * into the buffer. The buffer is aligned for any type 32ed424bb3SPrasannaKumar Muralidharan * and max is a multiple of 4 and >= 32 bytes. 33844dd05fSMichael Buesch * @priv: Private data, for use by the RNG driver. 340f734e6eSTorsten Duwe * @quality: Estimation of true entropy in RNG's bitstream 35fae29f13SMichael S. Tsirkin * (in bits of entropy per 1024 bits of input; 3616bdbae3SJason A. Donenfeld * valid values: 1 to 1024, or 0 for maximum). 37844dd05fSMichael Buesch */ 38844dd05fSMichael Buesch struct hwrng { 39844dd05fSMichael Buesch const char *name; 40844dd05fSMichael Buesch int (*init)(struct hwrng *rng); 41844dd05fSMichael Buesch void (*cleanup)(struct hwrng *rng); 42984e976fSPatrick McHardy int (*data_present)(struct hwrng *rng, int wait); 43844dd05fSMichael Buesch int (*data_read)(struct hwrng *rng, u32 *data); 449996508bSIan Molton int (*read)(struct hwrng *rng, void *data, size_t max, bool wait); 45844dd05fSMichael Buesch unsigned long priv; 460f734e6eSTorsten Duwe unsigned short quality; 47844dd05fSMichael Buesch 48844dd05fSMichael Buesch /* internal. */ 49844dd05fSMichael Buesch struct list_head list; 503a2c0ba5SRusty Russell struct kref ref; 5177584ee5SHerbert Xu struct completion cleanup_done; 5236cb6494SJason A. Donenfeld struct completion dying; 53844dd05fSMichael Buesch }; 54844dd05fSMichael Buesch 554d9b519cSDmitry Torokhov struct device; 564d9b519cSDmitry Torokhov 57844dd05fSMichael Buesch /** Register a new Hardware Random Number Generator driver. */ 58844dd05fSMichael Buesch extern int hwrng_register(struct hwrng *rng); 594d9b519cSDmitry Torokhov extern int devm_hwrng_register(struct device *dev, struct hwrng *rng); 60844dd05fSMichael Buesch /** Unregister a Hardware Random Number Generator driver. */ 61b844eba2SRafael J. Wysocki extern void hwrng_unregister(struct hwrng *rng); 624d9b519cSDmitry Torokhov extern void devm_hwrng_unregister(struct device *dve, struct hwrng *rng); 63844dd05fSMichael Buesch 6436cb6494SJason A. Donenfeld extern long hwrng_msleep(struct hwrng *rng, unsigned int msecs); 65b58a3600SStefan Wahren extern long hwrng_yield(struct hwrng *rng); 6636cb6494SJason A. Donenfeld 67844dd05fSMichael Buesch #endif /* LINUX_HWRANDOM_H_ */ 68