target/linux/brcm2708/patches-3.10/007-bcm2708_hw_random-driver.patch

   1 --- /dev/null
   2 +++ b/drivers/char/hw_random/bcm2708-rng.c
   3 @@ -0,0 +1,117 @@
   4 +/**
   5 + * Copyright (c) 2010-2012 Broadcom. All rights reserved.
   6 + *
   7 + * Redistribution and use in source and binary forms, with or without
   8 + * modification, are permitted provided that the following conditions
   9 + * are met:
  10 + * 1. Redistributions of source code must retain the above copyright
  11 + *    notice, this list of conditions, and the following disclaimer,
  12 + *    without modification.
  13 + * 2. Redistributions in binary form must reproduce the above copyright
  14 + *    notice, this list of conditions and the following disclaimer in the
  15 + *    documentation and/or other materials provided with the distribution.
  16 + * 3. The names of the above-listed copyright holders may not be used
  17 + *    to endorse or promote products derived from this software without
  18 + *    specific prior written permission.
  19 + *
  20 + * ALTERNATIVELY, this software may be distributed under the terms of the
  21 + * GNU General Public License ("GPL") version 2, as published by the Free
  22 + * Software Foundation.
  23 + *
  24 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  25 + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  26 + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  27 + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  28 + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  29 + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  30 + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  31 + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32 + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33 + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34 + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35 + */
  36 +
  37 +#include <linux/kernel.h>
  38 +#include <linux/module.h>
  39 +#include <linux/init.h>
  40 +#include <linux/hw_random.h>
  41 +#include <linux/printk.h>
  42 +
  43 +#include <asm/io.h>
  44 +#include <mach/hardware.h>
  45 +#include <mach/platform.h>
  46 +
  47 +#define RNG_CTRL               (0x0)
  48 +#define RNG_STATUS             (0x4)
  49 +#define RNG_DATA               (0x8)
  50 +#define RNG_FF_THRESHOLD       (0xc)
  51 +
  52 +/* enable rng */
  53 +#define RNG_RBGEN               0x1
  54 +/* double speed, less random mode */
  55 +#define RNG_RBG2X               0x2
  56 +
  57 +/* the initial numbers generated are "less random" so will be discarded */
  58 +#define RNG_WARMUP_COUNT      0x40000
  59 +
  60 +static int bcm2708_rng_data_read(struct hwrng *rng, u32 *buffer)
  61 +{
  62 +       void __iomem *rng_base = (void __iomem *)rng->priv;
  63 +       unsigned words;
  64 +       /* wait for a random number to be in fifo */
  65 +        do {
  66 +               words = __raw_readl(rng_base + RNG_STATUS)>>24;
  67 +       }
  68 +        while (words == 0);
  69 +       /* read the random number */
  70 +       *buffer = __raw_readl(rng_base + RNG_DATA);
  71 +       return 4;
  72 +}
  73 +
  74 +static struct hwrng bcm2708_rng_ops = {
  75 +       .name           = "bcm2708",
  76 +       .data_read      = bcm2708_rng_data_read,
  77 +};
  78 +
  79 +static int __init bcm2708_rng_init(void)
  80 +{
  81 +       void __iomem *rng_base;
  82 +       int err;
  83 +
  84 +       /* map peripheral */
  85 +       rng_base = ioremap(RNG_BASE, 0x10);
  86 +       pr_info("bcm2708_rng_init=%p\n", rng_base);
  87 +       if (!rng_base) {
  88 +               pr_err("bcm2708_rng_init failed to ioremap\n");
  89 +               return -ENOMEM;
  90 +       }
  91 +       bcm2708_rng_ops.priv = (unsigned long)rng_base;
  92 +       /* register driver */
  93 +       err = hwrng_register(&bcm2708_rng_ops);
  94 +       if (err) {
  95 +               pr_err("bcm2708_rng_init hwrng_register()=%d\n", err);
  96 +               iounmap(rng_base);
  97 +       } else {
  98 +               /* set warm-up count & enable */
  99 +               __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS);
 100 +               __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL);
 101 +       }
 102 +       return err;
 103 +}
 104 +
 105 +static void __exit bcm2708_rng_exit(void)
 106 +{
 107 +       void __iomem *rng_base = (void __iomem *)bcm2708_rng_ops.priv;
 108 +       pr_info("bcm2708_rng_exit\n");
 109 +       /* disable rng hardware */
 110 +       __raw_writel(0, rng_base + RNG_CTRL);
 111 +       /* unregister driver */
 112 +       hwrng_unregister(&bcm2708_rng_ops);
 113 +       iounmap(rng_base);
 114 +}
 115 +
 116 +module_init(bcm2708_rng_init);
 117 +module_exit(bcm2708_rng_exit);
 118 +
 119 +MODULE_DESCRIPTION("BCM2708 H/W Random Number Generator (RNG) driver");
 120 +MODULE_LICENSE("GPL and additional rights");
 121 --- a/drivers/char/hw_random/Kconfig
 122 +++ b/drivers/char/hw_random/Kconfig
 123 @@ -314,3 +314,15 @@ config HW_RANDOM_TPM
 124           module will be called tpm-rng.
 125
 126           If unsure, say Y.
 127 +
 128 +config HW_RANDOM_BCM2708
 129 +       tristate "BCM2708 generic true random number generator support"
 130 +       depends on HW_RANDOM && ARCH_BCM2708
 131 +       ---help---
 132 +        This driver provides the kernel-side support for the BCM2708 hardware.
 133 +
 134 +        To compile this driver as a module, choose M here: the
 135 +        module will be called bcm2708-rng.
 136 +
 137 +        If unsure, say N.
 138 +
 139 --- a/drivers/char/hw_random/Makefile
 140 +++ b/drivers/char/hw_random/Makefile
 141 @@ -27,3 +27,4 @@ obj-$(CONFIG_HW_RANDOM_PSERIES) += pseri
 142  obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o
 143  obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o
 144  obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
 145 +obj-$(CONFIG_HW_RANDOM_BCM2708) += bcm2708-rng.o