LXR linux/include/linux/hw

   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 */
  31struct 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. */
  44extern int hwrng_register(struct hwrng *rng);
  45/** Unregister a Hardware Random Number Generator driver. */
  46extern void hwrng_unregister(struct hwrng *rng);
  47
  48#endif /* LINUX_HWRANDOM_H_ */
  49