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

   1 From 1ecfdf8a7a08d52d238dc132c85d37966ca58737 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 047/196] 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 diff --git a/arch/arm/mach-bcm2708/include/mach/platform.h b/arch/arm/mach-bcm2708/include/mach/platform.h
  15 index 89e72d1..992a630 100644
  16 --- a/arch/arm/mach-bcm2708/include/mach/platform.h
  17 +++ b/arch/arm/mach-bcm2708/include/mach/platform.h
  18 @@ -62,6 +62,7 @@
  19  #define DMA_BASE                (BCM2708_PERI_BASE + 0x7000)   /* DMA controller */
  20  #define ARM_BASE                 (BCM2708_PERI_BASE + 0xB000)   /* BCM2708 ARM control block */
  21  #define PM_BASE                         (BCM2708_PERI_BASE + 0x100000) /* Power Management, Reset controller and Watchdog registers */
  22 +#define RNG_BASE                 (BCM2708_PERI_BASE + 0x104000) /* Hardware RNG */
  23  #define GPIO_BASE                (BCM2708_PERI_BASE + 0x200000) /* GPIO */
  24  #define UART0_BASE               (BCM2708_PERI_BASE + 0x201000)        /* Uart 0 */
  25  #define MMCI0_BASE               (BCM2708_PERI_BASE + 0x202000) /* MMC interface */
  26 diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
  27 index 2f9dbf7..d725a53 100644
  28 --- a/drivers/char/hw_random/Kconfig
  29 +++ b/drivers/char/hw_random/Kconfig
  30 @@ -314,3 +314,15 @@ config HW_RANDOM_TPM
  31           module will be called tpm-rng.
  32
  33           If unsure, say Y.
  34 +
  35 +config HW_RANDOM_BCM2708
  36 +       tristate "BCM2708 generic true random number generator support"
  37 +       depends on HW_RANDOM && ARCH_BCM2708
  38 +       ---help---
  39 +        This driver provides the kernel-side support for the BCM2708 hardware.
  40 +
  41 +        To compile this driver as a module, choose M here: the
  42 +        module will be called bcm2708-rng.
  43 +
  44 +        If unsure, say N.
  45 +
  46 diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
  47 index bed467c..18fc4d4 100644
  48 --- a/drivers/char/hw_random/Makefile
  49 +++ b/drivers/char/hw_random/Makefile
  50 @@ -27,3 +27,4 @@ obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
  51  obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o
  52  obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o
  53  obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
  54 +obj-$(CONFIG_HW_RANDOM_BCM2708) += bcm2708-rng.o
  55 diff --git a/drivers/char/hw_random/bcm2708-rng.c b/drivers/char/hw_random/bcm2708-rng.c
  56 new file mode 100755
  57 index 0000000..1ffa7d7
  58 --- /dev/null
  59 +++ b/drivers/char/hw_random/bcm2708-rng.c
  60 @@ -0,0 +1,117 @@
  61 +/**
  62 + * Copyright (c) 2010-2012 Broadcom. All rights reserved.
  63 + *
  64 + * Redistribution and use in source and binary forms, with or without
  65 + * modification, are permitted provided that the following conditions
  66 + * are met:
  67 + * 1. Redistributions of source code must retain the above copyright
  68 + *    notice, this list of conditions, and the following disclaimer,
  69 + *    without modification.
  70 + * 2. Redistributions in binary form must reproduce the above copyright
  71 + *    notice, this list of conditions and the following disclaimer in the
  72 + *    documentation and/or other materials provided with the distribution.
  73 + * 3. The names of the above-listed copyright holders may not be used
  74 + *    to endorse or promote products derived from this software without
  75 + *    specific prior written permission.
  76 + *
  77 + * ALTERNATIVELY, this software may be distributed under the terms of the
  78 + * GNU General Public License ("GPL") version 2, as published by the Free
  79 + * Software Foundation.
  80 + *
  81 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  82 + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  83 + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  84 + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  85 + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  86 + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  87 + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  88 + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  89 + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  90 + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  91 + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  92 + */
  93 +
  94 +#include <linux/kernel.h>
  95 +#include <linux/module.h>
  96 +#include <linux/init.h>
  97 +#include <linux/hw_random.h>
  98 +#include <linux/printk.h>
  99 +
 100 +#include <asm/io.h>
 101 +#include <mach/hardware.h>
 102 +#include <mach/platform.h>
 103 +
 104 +#define RNG_CTRL               (0x0)
 105 +#define RNG_STATUS             (0x4)
 106 +#define RNG_DATA               (0x8)
 107 +#define RNG_FF_THRESHOLD       (0xc)
 108 +
 109 +/* enable rng */
 110 +#define RNG_RBGEN               0x1
 111 +/* double speed, less random mode */
 112 +#define RNG_RBG2X               0x2
 113 +
 114 +/* the initial numbers generated are "less random" so will be discarded */
 115 +#define RNG_WARMUP_COUNT      0x40000
 116 +
 117 +static int bcm2708_rng_data_read(struct hwrng *rng, u32 *buffer)
 118 +{
 119 +       void __iomem *rng_base = (void __iomem *)rng->priv;
 120 +       unsigned words;
 121 +       /* wait for a random number to be in fifo */
 122 +        do {
 123 +               words = __raw_readl(rng_base + RNG_STATUS)>>24;
 124 +       }
 125 +        while (words == 0);
 126 +       /* read the random number */
 127 +       *buffer = __raw_readl(rng_base + RNG_DATA);
 128 +       return 4;
 129 +}
 130 +
 131 +static struct hwrng bcm2708_rng_ops = {
 132 +       .name           = "bcm2708",
 133 +       .data_read      = bcm2708_rng_data_read,
 134 +};
 135 +
 136 +static int __init bcm2708_rng_init(void)
 137 +{
 138 +       void __iomem *rng_base;
 139 +       int err;
 140 +
 141 +       /* map peripheral */
 142 +       rng_base = ioremap(RNG_BASE, 0x10);
 143 +       pr_info("bcm2708_rng_init=%p\n", rng_base);
 144 +       if (!rng_base) {
 145 +               pr_err("bcm2708_rng_init failed to ioremap\n");
 146 +               return -ENOMEM;
 147 +       }
 148 +       bcm2708_rng_ops.priv = (unsigned long)rng_base;
 149 +       /* register driver */
 150 +       err = hwrng_register(&bcm2708_rng_ops);
 151 +       if (err) {
 152 +               pr_err("bcm2708_rng_init hwrng_register()=%d\n", err);
 153 +               iounmap(rng_base);
 154 +       } else {
 155 +               /* set warm-up count & enable */
 156 +               __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS);
 157 +               __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL);
 158 +       }
 159 +       return err;
 160 +}
 161 +
 162 +static void __exit bcm2708_rng_exit(void)
 163 +{
 164 +       void __iomem *rng_base = (void __iomem *)bcm2708_rng_ops.priv;
 165 +       pr_info("bcm2708_rng_exit\n");
 166 +       /* disable rng hardware */
 167 +       __raw_writel(0, rng_base + RNG_CTRL);
 168 +       /* unregister driver */
 169 +       hwrng_unregister(&bcm2708_rng_ops);
 170 +       iounmap(rng_base);
 171 +}
 172 +
 173 +module_init(bcm2708_rng_init);
 174 +module_exit(bcm2708_rng_exit);
 175 +
 176 +MODULE_DESCRIPTION("BCM2708 H/W Random Number Generator (RNG) driver");
 177 +MODULE_LICENSE("GPL and additional rights");
 178 --
 179 1.9.1
 180