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 */
37struct 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
53struct device;
54
55/** Register a new Hardware Random Number Generator driver. */
56extern int hwrng_register(struct hwrng *rng);
57extern int devm_hwrng_register(struct device *dev, struct hwrng *rng);
58/** Unregister a Hardware Random Number Generator driver. */
59extern void hwrng_unregister(struct hwrng *rng);
60extern void devm_hwrng_unregister(struct device *dve, struct hwrng *rng);
61/** Feed random bits into the pool. */
62extern void add_hwgenerator_randomness(const char *buffer, size_t count, size_t entropy);
63
64#endif /* LINUX_HWRANDOM_H_ */
65