/*
  	Hardware Random Number Generator
  
  	Please read Documentation/hw_random.txt for details on use.
  
  	----------------------------------------------------------
  	This software may be used and distributed according to the terms
          of the GNU General Public License, incorporated herein by reference.
  
   */
  
  #ifndef LINUX_HWRANDOM_H_
  #define LINUX_HWRANDOM_H_

  #include <linux/completion.h>

  #include <linux/types.h>
  #include <linux/list.h>

  #include <linux/kref.h>

  
  /**
   * struct hwrng - Hardware Random Number Generator driver
   * @name:		Unique RNG name.
   * @init:		Initialization callback (can be NULL).
   * @cleanup:		Cleanup callback (can be NULL).
   * @data_present:	Callback to determine if data is available
   *			on the RNG. If NULL, it is assumed that

   *			there is always data available.  *OBSOLETE*

   * @data_read:		Read data from the RNG device.
   *			Returns the number of lower random bytes in "data".

   *			Must not be NULL.    *OBSOLETE*

   * @read:		New API. drivers can fill up to max bytes of data

   *			into the buffer. The buffer is aligned for any type
   *			and max is guaranteed to be >= to that alignment
   *			(either 4 or 8 depending on architecture).

   * @priv:		Private data, for use by the RNG driver.

   * @quality:		Estimation of true entropy in RNG's bitstream
   *			(per mill).

   */
  struct hwrng {
  	const char *name;
  	int (*init)(struct hwrng *rng);
  	void (*cleanup)(struct hwrng *rng);

  	int (*data_present)(struct hwrng *rng, int wait);

  	int (*data_read)(struct hwrng *rng, u32 *data);

  	int (*read)(struct hwrng *rng, void *data, size_t max, bool wait);

  	unsigned long priv;

  	unsigned short quality;

  
  	/* internal. */
  	struct list_head list;

  	struct kref ref;

  	struct completion cleanup_done;

  };

  struct device;

  /** Register a new Hardware Random Number Generator driver. */
  extern int hwrng_register(struct hwrng *rng);

  extern int devm_hwrng_register(struct device *dev, struct hwrng *rng);

  /** Unregister a Hardware Random Number Generator driver. */

  extern void hwrng_unregister(struct hwrng *rng);

  extern void devm_hwrng_unregister(struct device *dve, struct hwrng *rng);

  /** Feed random bits into the pool. */
  extern void add_hwgenerator_randomness(const char *buffer, size_t count, size_t entropy);

  #endif /* LINUX_HWRANDOM_H_ */