target/linux/brcm2708/patches-3.10/0047-Add-hwrng-hardware-random-number-generator-driver.patch

   1 From 8a467ffd4cdce4f87c363c24be193b99b2688126 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 047/174] Add hwrng (hardware random number generator) driver
   5
   6 ---
   7  arch/arm/mach-bcm2708/include/mach/platform.h |   1 +
   8  drivers/char/hw_random/Kconfig                |  12 +++
   9  drivers/char/hw_random/Makefile               |   1 +
  10  drivers/char/hw_random/bcm2708-rng.c          | 117 ++++++++++++++++++++++++++
  11  4 files changed, 131 insertions(+)
  12  create mode 100755 drivers/char/hw_random/bcm2708-rng.c
  13
  14 --- a/arch/arm/mach-bcm2708/include/mach/platform.h
  15 +++ b/arch/arm/mach-bcm2708/include/mach/platform.h
  16 @@ -62,6 +62,7 @@
  17  #define DMA_BASE                (BCM2708_PERI_BASE + 0x7000)   /* DMA controller */
  18  #define ARM_BASE                 (BCM2708_PERI_BASE + 0xB000)   /* BCM2708 ARM control block */
  19  #define PM_BASE                         (BCM2708_PERI_BASE + 0x100000) /* Power Management, Reset controller and Watchdog registers */
  20 +#define RNG_BASE                 (BCM2708_PERI_BASE + 0x104000) /* Hardware RNG */
  21  #define GPIO_BASE                (BCM2708_PERI_BASE + 0x200000) /* GPIO */
  22  #define UART0_BASE               (BCM2708_PERI_BASE + 0x201000)        /* Uart 0 */
  23  #define MMCI0_BASE               (BCM2708_PERI_BASE + 0x202000) /* MMC interface */
  24 --- a/drivers/char/hw_random/Kconfig
  25 +++ b/drivers/char/hw_random/Kconfig
  26 @@ -314,3 +314,15 @@ config HW_RANDOM_TPM
  27           module will be called tpm-rng.
  28
  29           If unsure, say Y.
  30 +
  31 +config HW_RANDOM_BCM2708
  32 +       tristate "BCM2708 generic true random number generator support"
  33 +       depends on HW_RANDOM && ARCH_BCM2708
  34 +       ---help---
  35 +        This driver provides the kernel-side support for the BCM2708 hardware.
  36 +
  37 +        To compile this driver as a module, choose M here: the
  38 +        module will be called bcm2708-rng.
  39 +
  40 +        If unsure, say N.
  41 +
  42 --- a/drivers/char/hw_random/Makefile
  43 +++ b/drivers/char/hw_random/Makefile
  44 @@ -27,3 +27,4 @@ obj-$(CONFIG_HW_RANDOM_PSERIES) += pseri
  45  obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o
  46  obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o
  47  obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
  48 +obj-$(CONFIG_HW_RANDOM_BCM2708) += bcm2708-rng.o
  49 --- /dev/null
  50 +++ b/drivers/char/hw_random/bcm2708-rng.c
  51 @@ -0,0 +1,117 @@
  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 +       /* register driver */
 141 +       err = hwrng_register(&bcm2708_rng_ops);
 142 +       if (err) {
 143 +               pr_err("bcm2708_rng_init hwrng_register()=%d\n", err);
 144 +               iounmap(rng_base);
 145 +       } else {
 146 +               /* set warm-up count & enable */
 147 +               __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS);
 148 +               __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL);
 149 +       }
 150 +       return err;
 151 +}
 152 +
 153 +static void __exit bcm2708_rng_exit(void)
 154 +{
 155 +       void __iomem *rng_base = (void __iomem *)bcm2708_rng_ops.priv;
 156 +       pr_info("bcm2708_rng_exit\n");
 157 +       /* disable rng hardware */
 158 +       __raw_writel(0, rng_base + RNG_CTRL);
 159 +       /* unregister driver */
 160 +       hwrng_unregister(&bcm2708_rng_ops);
 161 +       iounmap(rng_base);
 162 +}
 163 +
 164 +module_init(bcm2708_rng_init);
 165 +module_exit(bcm2708_rng_exit);
 166 +
 167 +MODULE_DESCRIPTION("BCM2708 H/W Random Number Generator (RNG) driver");
 168 +MODULE_LICENSE("GPL and additional rights");