// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * Copyright (c) 2019, Linaro Limited

 */

#include <dm.h>

#include <rand.h>

#include <rng.h>

#include <time.h>

#include <linux/string.h>

static int sandbox_rng_read(struct udevice *dev, void *data, size_t len)

{

  unsigned int i, seed, random;

  unsigned char *buf = data;

  size_t nrem, nloops;

  if (!len)

    return 0;

  nloops = len / sizeof(random);

  seed = get_timer(0) ^ rand();

  srand(seed);

  for (i = 0, nrem = len; i < nloops; i++) {

    random = rand();

    memcpy(buf, &random, sizeof(random));

    buf += sizeof(random);

    nrem -= sizeof(random);

  }

  if (nrem) {

    random = rand();

    memcpy(buf, &random, nrem);

  }

  return 0;

}

static const struct dm_rng_ops sandbox_rng_ops = {

  .read = sandbox_rng_read,

};

static const struct udevice_id sandbox_rng_match[] = {

  {

    .compatible = "sandbox,sandbox-rng",

  },

  {},

};

U_BOOT_DRIVER(sandbox_rng) = {

  .name = "sandbox-rng",

  .id = UCLASS_RNG,

  .of_match = sandbox_rng_match,

  .ops = &sandbox_rng_ops,

};