target/linux/brcm2708/patches-3.14/0011-Add-hwrng-hardware-random-number-generator-driver.patch

   1 From 2bae9a662d169ecb7d3e1c39ebbcbc80b7dc845f 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 11/54] 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                |  11 +++
   9  drivers/char/hw_random/Makefile               |   1 +
  10  drivers/char/hw_random/bcm2708-rng.c          | 117 ++++++++++++++++++++++++++
  11  4 files changed, 130 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 110ce07..ecd854e 100644
  16 --- a/arch/arm/mach-bcm2708/include/mach/platform.h
  17 +++ b/arch/arm/mach-bcm2708/include/mach/platform.h
  18 @@ -60,6 +60,7 @@
  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 2f2b084..cfca8e9 100644
  28 --- a/drivers/char/hw_random/Kconfig
  29 +++ b/drivers/char/hw_random/Kconfig
  30 @@ -341,6 +341,17 @@ config HW_RANDOM_TPM
  31
  32           If unsure, say Y.
  33
  34 +config HW_RANDOM_BCM2708
  35 +       tristate "BCM2708 generic true random number generator support"
  36 +       depends on HW_RANDOM && ARCH_BCM2708
  37 +       ---help---
  38 +        This driver provides the kernel-side support for the BCM2708 hardware.
  39 +
  40 +        To compile this driver as a module, choose M here: the
  41 +        module will be called bcm2708-rng.
  42 +
  43 +        If unsure, say N.
  44 +
  45  config HW_RANDOM_MSM
  46         tristate "Qualcomm MSM Random Number Generator support"
  47         depends on HW_RANDOM && ARCH_MSM
  48 diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
  49 index 3ae7755..a7bfb80 100644
  50 --- a/drivers/char/hw_random/Makefile
  51 +++ b/drivers/char/hw_random/Makefile
  52 @@ -29,4 +29,5 @@ obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o
  53  obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o
  54  obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o
  55  obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
  56 +obj-$(CONFIG_HW_RANDOM_BCM2708) += bcm2708-rng.o
  57  obj-$(CONFIG_HW_RANDOM_MSM) += msm-rng.o
  58 diff --git a/drivers/char/hw_random/bcm2708-rng.c b/drivers/char/hw_random/bcm2708-rng.c
  59 new file mode 100755
  60 index 0000000..1ffa7d7
  61 --- /dev/null
  62 +++ b/drivers/char/hw_random/bcm2708-rng.c
  63 @@ -0,0 +1,117 @@
  64 +/**
  65 + * Copyright (c) 2010-2012 Broadcom. All rights reserved.
  66 + *
  67 + * Redistribution and use in source and binary forms, with or without
  68 + * modification, are permitted provided that the following conditions
  69 + * are met:
  70 + * 1. Redistributions of source code must retain the above copyright
  71 + *    notice, this list of conditions, and the following disclaimer,
  72 + *    without modification.
  73 + * 2. Redistributions in binary form must reproduce the above copyright
  74 + *    notice, this list of conditions and the following disclaimer in the
  75 + *    documentation and/or other materials provided with the distribution.
  76 + * 3. The names of the above-listed copyright holders may not be used
  77 + *    to endorse or promote products derived from this software without
  78 + *    specific prior written permission.
  79 + *
  80 + * ALTERNATIVELY, this software may be distributed under the terms of the
  81 + * GNU General Public License ("GPL") version 2, as published by the Free
  82 + * Software Foundation.
  83 + *
  84 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  85 + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  86 + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  87 + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  88 + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  89 + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  90 + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  91 + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  92 + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  93 + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  94 + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  95 + */
  96 +
  97 +#include <linux/kernel.h>
  98 +#include <linux/module.h>
  99 +#include <linux/init.h>
 100 +#include <linux/hw_random.h>
 101 +#include <linux/printk.h>
 102 +
 103 +#include <asm/io.h>
 104 +#include <mach/hardware.h>
 105 +#include <mach/platform.h>
 106 +
 107 +#define RNG_CTRL               (0x0)
 108 +#define RNG_STATUS             (0x4)
 109 +#define RNG_DATA               (0x8)
 110 +#define RNG_FF_THRESHOLD       (0xc)
 111 +
 112 +/* enable rng */
 113 +#define RNG_RBGEN               0x1
 114 +/* double speed, less random mode */
 115 +#define RNG_RBG2X               0x2
 116 +
 117 +/* the initial numbers generated are "less random" so will be discarded */
 118 +#define RNG_WARMUP_COUNT      0x40000
 119 +
 120 +static int bcm2708_rng_data_read(struct hwrng *rng, u32 *buffer)
 121 +{
 122 +       void __iomem *rng_base = (void __iomem *)rng->priv;
 123 +       unsigned words;
 124 +       /* wait for a random number to be in fifo */
 125 +        do {
 126 +               words = __raw_readl(rng_base + RNG_STATUS)>>24;
 127 +       }
 128 +        while (words == 0);
 129 +       /* read the random number */
 130 +       *buffer = __raw_readl(rng_base + RNG_DATA);
 131 +       return 4;
 132 +}
 133 +
 134 +static struct hwrng bcm2708_rng_ops = {
 135 +       .name           = "bcm2708",
 136 +       .data_read      = bcm2708_rng_data_read,
 137 +};
 138 +
 139 +static int __init bcm2708_rng_init(void)
 140 +{
 141 +       void __iomem *rng_base;
 142 +       int err;
 143 +
 144 +       /* map peripheral */
 145 +       rng_base = ioremap(RNG_BASE, 0x10);
 146 +       pr_info("bcm2708_rng_init=%p\n", rng_base);
 147 +       if (!rng_base) {
 148 +               pr_err("bcm2708_rng_init failed to ioremap\n");
 149 +               return -ENOMEM;
 150 +       }
 151 +       bcm2708_rng_ops.priv = (unsigned long)rng_base;
 152 +       /* register driver */
 153 +       err = hwrng_register(&bcm2708_rng_ops);
 154 +       if (err) {
 155 +               pr_err("bcm2708_rng_init hwrng_register()=%d\n", err);
 156 +               iounmap(rng_base);
 157 +       } else {
 158 +               /* set warm-up count & enable */
 159 +               __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS);
 160 +               __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL);
 161 +       }
 162 +       return err;
 163 +}
 164 +
 165 +static void __exit bcm2708_rng_exit(void)
 166 +{
 167 +       void __iomem *rng_base = (void __iomem *)bcm2708_rng_ops.priv;
 168 +       pr_info("bcm2708_rng_exit\n");
 169 +       /* disable rng hardware */
 170 +       __raw_writel(0, rng_base + RNG_CTRL);
 171 +       /* unregister driver */
 172 +       hwrng_unregister(&bcm2708_rng_ops);
 173 +       iounmap(rng_base);
 174 +}
 175 +
 176 +module_init(bcm2708_rng_init);
 177 +module_exit(bcm2708_rng_exit);
 178 +
 179 +MODULE_DESCRIPTION("BCM2708 H/W Random Number Generator (RNG) driver");
 180 +MODULE_LICENSE("GPL and additional rights");
 181 --
 182 1.9.1
 183