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
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
14 --- a/arch/arm/mach-bcm2708/include/mach/platform.h
15 +++ b/arch/arm/mach-bcm2708/include/mach/platform.h
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.
31 +config HW_RANDOM_BCM2708
32 + tristate "BCM2708 generic true random number generator support"
33 + depends on HW_RANDOM && ARCH_BCM2708
35 + This driver provides the kernel-side support for the BCM2708 hardware.
37 + To compile this driver as a module, choose M here: the
38 + module will be called bcm2708-rng.
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
50 +++ b/drivers/char/hw_random/bcm2708-rng.c
53 + * Copyright (c) 2010-2012 Broadcom. All rights reserved.
55 + * Redistribution and use in source and binary forms, with or without
56 + * modification, are permitted provided that the following conditions
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.
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.
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.
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>
92 +#include <mach/hardware.h>
93 +#include <mach/platform.h>
95 +#define RNG_CTRL (0x0)
96 +#define RNG_STATUS (0x4)
97 +#define RNG_DATA (0x8)
98 +#define RNG_FF_THRESHOLD (0xc)
101 +#define RNG_RBGEN 0x1
102 +/* double speed, less random mode */
103 +#define RNG_RBG2X 0x2
105 +/* the initial numbers generated are "less random" so will be discarded */
106 +#define RNG_WARMUP_COUNT 0x40000
108 +static int bcm2708_rng_data_read(struct hwrng *rng, u32 *buffer)
110 + void __iomem *rng_base = (void __iomem *)rng->priv;
112 + /* wait for a random number to be in fifo */
114 + words = __raw_readl(rng_base + RNG_STATUS)>>24;
116 + while (words == 0);
117 + /* read the random number */
118 + *buffer = __raw_readl(rng_base + RNG_DATA);
122 +static struct hwrng bcm2708_rng_ops = {
124 + .data_read = bcm2708_rng_data_read,
127 +static int __init bcm2708_rng_init(void)
129 + void __iomem *rng_base;
132 + /* map peripheral */
133 + rng_base = ioremap(RNG_BASE, 0x10);
134 + pr_info("bcm2708_rng_init=%p\n", rng_base);
136 + pr_err("bcm2708_rng_init failed to ioremap\n");
139 + bcm2708_rng_ops.priv = (unsigned long)rng_base;
140 + /* register driver */
141 + err = hwrng_register(&bcm2708_rng_ops);
143 + pr_err("bcm2708_rng_init hwrng_register()=%d\n", err);
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);
153 +static void __exit bcm2708_rng_exit(void)
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);
164 +module_init(bcm2708_rng_init);
165 +module_exit(bcm2708_rng_exit);
167 +MODULE_DESCRIPTION("BCM2708 H/W Random Number Generator (RNG) driver");
168 +MODULE_LICENSE("GPL and additional rights");