target/linux/brcm2708/patches-3.18/0014-Add-hwrng-hardware-random-number-generator-driver.patch

   1 From 225e1250dfcec7b09493b6a86bdeaab9f2669221 Mon Sep 17 00:00:00 2001
   2 From: popcornmix <popcornmix@gmail.com>
   3 Date: Wed, 3 Jul 2013 00:51:55 +0100
   4 Subject: [PATCH 014/114] Add hwrng (hardware random number generator) driver
   5
   6 ---
   7  drivers/char/hw_random/Kconfig       |  11 ++++
   8  drivers/char/hw_random/Makefile      |   1 +
   9  drivers/char/hw_random/bcm2708-rng.c | 118 +++++++++++++++++++++++++++++++++++
  10  3 files changed, 130 insertions(+)
  11  create mode 100755 drivers/char/hw_random/bcm2708-rng.c
  12
  13 diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
  14 index 91a04ae..0d2ca0d 100644
  15 --- a/drivers/char/hw_random/Kconfig
  16 +++ b/drivers/char/hw_random/Kconfig
  17 @@ -320,6 +320,17 @@ config HW_RANDOM_TPM
  18
  19           If unsure, say Y.
  20
  21 +config HW_RANDOM_BCM2708
  22 +       tristate "BCM2708 generic true random number generator support"
  23 +       depends on HW_RANDOM && ARCH_BCM2708
  24 +       ---help---
  25 +        This driver provides the kernel-side support for the BCM2708 hardware.
  26 +
  27 +        To compile this driver as a module, choose M here: the
  28 +        module will be called bcm2708-rng.
  29 +
  30 +        If unsure, say N.
  31 +
  32  config HW_RANDOM_MSM
  33         tristate "Qualcomm SoCs Random Number Generator support"
  34         depends on HW_RANDOM && ARCH_QCOM
  35 diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
  36 index 0b4cd57..78b019c 100644
  37 --- a/drivers/char/hw_random/Makefile
  38 +++ b/drivers/char/hw_random/Makefile
  39 @@ -28,5 +28,6 @@ obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o
  40  obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o
  41  obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o
  42  obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
  43 +obj-$(CONFIG_HW_RANDOM_BCM2708) += bcm2708-rng.o
  44  obj-$(CONFIG_HW_RANDOM_MSM) += msm-rng.o
  45  obj-$(CONFIG_HW_RANDOM_XGENE) += xgene-rng.o
  46 diff --git a/drivers/char/hw_random/bcm2708-rng.c b/drivers/char/hw_random/bcm2708-rng.c
  47 new file mode 100755
  48 index 0000000..340f004
  49 --- /dev/null
  50 +++ b/drivers/char/hw_random/bcm2708-rng.c
  51 @@ -0,0 +1,118 @@
  52 +/**
  53 + * Copyright (c) 2010-2012 Broadcom. All rights reserved.
  54 + *
  55 + * Redistribution and use in source and binary forms, with or without
  56 + * modification, are permitted provided that the following conditions
  57 + * are met:
  58 + * 1. Redistributions of source code must retain the above copyright
  59 + *    notice, this list of conditions, and the following disclaimer,
  60 + *    without modification.
  61 + * 2. Redistributions in binary form must reproduce the above copyright
  62 + *    notice, this list of conditions and the following disclaimer in the
  63 + *    documentation and/or other materials provided with the distribution.
  64 + * 3. The names of the above-listed copyright holders may not be used
  65 + *    to endorse or promote products derived from this software without
  66 + *    specific prior written permission.
  67 + *
  68 + * ALTERNATIVELY, this software may be distributed under the terms of the
  69 + * GNU General Public License ("GPL") version 2, as published by the Free
  70 + * Software Foundation.
  71 + *
  72 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  73 + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  74 + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  75 + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  76 + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  77 + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  78 + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  79 + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  80 + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  81 + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  82 + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  83 + */
  84 +
  85 +#include <linux/kernel.h>
  86 +#include <linux/module.h>
  87 +#include <linux/init.h>
  88 +#include <linux/hw_random.h>
  89 +#include <linux/printk.h>
  90 +
  91 +#include <asm/io.h>
  92 +#include <mach/hardware.h>
  93 +#include <mach/platform.h>
  94 +
  95 +#define RNG_CTRL               (0x0)
  96 +#define RNG_STATUS             (0x4)
  97 +#define RNG_DATA               (0x8)
  98 +#define RNG_FF_THRESHOLD       (0xc)
  99 +
 100 +/* enable rng */
 101 +#define RNG_RBGEN               0x1
 102 +/* double speed, less random mode */
 103 +#define RNG_RBG2X               0x2
 104 +
 105 +/* the initial numbers generated are "less random" so will be discarded */
 106 +#define RNG_WARMUP_COUNT      0x40000
 107 +
 108 +static int bcm2708_rng_data_read(struct hwrng *rng, u32 *buffer)
 109 +{
 110 +       void __iomem *rng_base = (void __iomem *)rng->priv;
 111 +       unsigned words;
 112 +       /* wait for a random number to be in fifo */
 113 +        do {
 114 +               words = __raw_readl(rng_base + RNG_STATUS)>>24;
 115 +       }
 116 +        while (words == 0);
 117 +       /* read the random number */
 118 +       *buffer = __raw_readl(rng_base + RNG_DATA);
 119 +       return 4;
 120 +}
 121 +
 122 +static struct hwrng bcm2708_rng_ops = {
 123 +       .name           = "bcm2708",
 124 +       .data_read      = bcm2708_rng_data_read,
 125 +};
 126 +
 127 +static int __init bcm2708_rng_init(void)
 128 +{
 129 +       void __iomem *rng_base;
 130 +       int err;
 131 +
 132 +       /* map peripheral */
 133 +       rng_base = ioremap(RNG_BASE, 0x10);
 134 +       pr_info("bcm2708_rng_init=%p\n", rng_base);
 135 +       if (!rng_base) {
 136 +               pr_err("bcm2708_rng_init failed to ioremap\n");
 137 +               return -ENOMEM;
 138 +       }
 139 +       bcm2708_rng_ops.priv = (unsigned long)rng_base;
 140 +
 141 +       /* set warm-up count & enable */
 142 +       __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS);
 143 +       __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL);
 144 +
 145 +       /* register driver */
 146 +       err = hwrng_register(&bcm2708_rng_ops);
 147 +       if (err) {
 148 +               pr_err("bcm2708_rng_init hwrng_register()=%d\n", err);
 149 +               iounmap(rng_base);
 150 +       }
 151 +       return err;
 152 +}
 153 +
 154 +static void __exit bcm2708_rng_exit(void)
 155 +{
 156 +       void __iomem *rng_base = (void __iomem *)bcm2708_rng_ops.priv;
 157 +       pr_info("bcm2708_rng_exit\n");
 158 +       /* disable rng hardware */
 159 +       __raw_writel(0, rng_base + RNG_CTRL);
 160 +       /* unregister driver */
 161 +       hwrng_unregister(&bcm2708_rng_ops);
 162 +       iounmap(rng_base);
 163 +}
 164 +
 165 +module_init(bcm2708_rng_init);
 166 +module_exit(bcm2708_rng_exit);
 167 +
 168 +MODULE_DESCRIPTION("BCM2708 H/W Random Number Generator (RNG) driver");
 169 +MODULE_LICENSE("GPL and additional rights");
 170 --
 171 1.8.3.2
 172