// SPDX-License-Identifier: GPL-2.0+
  /*
   * Copyright (c) 2019, Linaro Limited
   */
  
  #if !defined _RNG_H_
  #define _RNG_H_
  
  struct udevice;
  
  /**
   * dm_rng_read() - read a random number seed from the rng device
   * @buffer:	input buffer to put the read random seed into
   * @size:	number of bytes of random seed read
   *
   * Return: 0 if OK, -ve on error
   */
  int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
  
  /* struct dm_rng_ops - Operations for the hwrng uclass */
  struct dm_rng_ops {
  	/**
  	 * @read() - read a random number seed
  	 *
  	 * @data:	input buffer to read the random seed
  	 * @max:	total number of bytes to read
  	 *
  	 * Return: 0 if OK, -ve on error
  	 */
  	int (*read)(struct udevice *dev, void *data, size_t max);
  };
  
  #endif /* _RNG_H_ */