1 From b710de7ce2b20537d03f9f083f0cf5168db2cc84 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 015/222] Add hwrng (hardware random number generator) driver
7 drivers/char/hw_random/Kconfig | 13 +++-
8 drivers/char/hw_random/Makefile | 1 +
9 drivers/char/hw_random/bcm2708-rng.c | 118 +++++++++++++++++++++++++++++++++++
10 3 files changed, 131 insertions(+), 1 deletion(-)
11 create mode 100755 drivers/char/hw_random/bcm2708-rng.c
13 --- a/drivers/char/hw_random/Kconfig
14 +++ b/drivers/char/hw_random/Kconfig
15 @@ -90,7 +90,7 @@ config HW_RANDOM_BCM63XX
17 config HW_RANDOM_BCM2835
18 tristate "Broadcom BCM2835 Random Number Generator support"
19 - depends on ARCH_BCM2835
20 + depends on ARCH_BCM2835 || ARCH_BCM2708 || ARCH_BCM2709
23 This driver provides kernel-side support for the Random Number
24 @@ -333,6 +333,17 @@ config HW_RANDOM_TPM
28 +config HW_RANDOM_BCM2708
29 + tristate "BCM2708 generic true random number generator support"
30 + depends on HW_RANDOM && (ARCH_BCM2708 || ARCH_BCM2709)
32 + This driver provides the kernel-side support for the BCM2708 hardware.
34 + To compile this driver as a module, choose M here: the
35 + module will be called bcm2708-rng.
40 tristate "Qualcomm SoCs Random Number Generator support"
41 depends on HW_RANDOM && ARCH_QCOM
42 --- a/drivers/char/hw_random/Makefile
43 +++ b/drivers/char/hw_random/Makefile
46 obj-$(CONFIG_HW_RANDOM) += rng-core.o
48 +obj-$(CONFIG_HW_RANDOM_BCM2708) += bcm2708-rng.o
49 obj-$(CONFIG_HW_RANDOM_TIMERIOMEM) += timeriomem-rng.o
50 obj-$(CONFIG_HW_RANDOM_INTEL) += intel-rng.o
51 obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o
53 +++ b/drivers/char/hw_random/bcm2708-rng.c
56 + * Copyright (c) 2010-2012 Broadcom. All rights reserved.
58 + * Redistribution and use in source and binary forms, with or without
59 + * modification, are permitted provided that the following conditions
61 + * 1. Redistributions of source code must retain the above copyright
62 + * notice, this list of conditions, and the following disclaimer,
63 + * without modification.
64 + * 2. Redistributions in binary form must reproduce the above copyright
65 + * notice, this list of conditions and the following disclaimer in the
66 + * documentation and/or other materials provided with the distribution.
67 + * 3. The names of the above-listed copyright holders may not be used
68 + * to endorse or promote products derived from this software without
69 + * specific prior written permission.
71 + * ALTERNATIVELY, this software may be distributed under the terms of the
72 + * GNU General Public License ("GPL") version 2, as published by the Free
73 + * Software Foundation.
75 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
76 + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
77 + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
78 + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
79 + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
80 + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
81 + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
82 + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
83 + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
84 + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
85 + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
88 +#include <linux/kernel.h>
89 +#include <linux/module.h>
90 +#include <linux/init.h>
91 +#include <linux/hw_random.h>
92 +#include <linux/printk.h>
95 +#include <mach/hardware.h>
96 +#include <mach/platform.h>
98 +#define RNG_CTRL (0x0)
99 +#define RNG_STATUS (0x4)
100 +#define RNG_DATA (0x8)
101 +#define RNG_FF_THRESHOLD (0xc)
104 +#define RNG_RBGEN 0x1
105 +/* double speed, less random mode */
106 +#define RNG_RBG2X 0x2
108 +/* the initial numbers generated are "less random" so will be discarded */
109 +#define RNG_WARMUP_COUNT 0x40000
111 +static int bcm2708_rng_data_read(struct hwrng *rng, u32 *buffer)
113 + void __iomem *rng_base = (void __iomem *)rng->priv;
115 + /* wait for a random number to be in fifo */
117 + words = __raw_readl(rng_base + RNG_STATUS)>>24;
119 + while (words == 0);
120 + /* read the random number */
121 + *buffer = __raw_readl(rng_base + RNG_DATA);
125 +static struct hwrng bcm2708_rng_ops = {
127 + .data_read = bcm2708_rng_data_read,
130 +static int __init bcm2708_rng_init(void)
132 + void __iomem *rng_base;
135 + /* map peripheral */
136 + rng_base = ioremap(RNG_BASE, 0x10);
137 + pr_info("bcm2708_rng_init=%p\n", rng_base);
139 + pr_err("bcm2708_rng_init failed to ioremap\n");
142 + bcm2708_rng_ops.priv = (unsigned long)rng_base;
144 + /* set warm-up count & enable */
145 + __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS);
146 + __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL);
148 + /* register driver */
149 + err = hwrng_register(&bcm2708_rng_ops);
151 + pr_err("bcm2708_rng_init hwrng_register()=%d\n", err);
157 +static void __exit bcm2708_rng_exit(void)
159 + void __iomem *rng_base = (void __iomem *)bcm2708_rng_ops.priv;
160 + pr_info("bcm2708_rng_exit\n");
161 + /* disable rng hardware */
162 + __raw_writel(0, rng_base + RNG_CTRL);
163 + /* unregister driver */
164 + hwrng_unregister(&bcm2708_rng_ops);
168 +module_init(bcm2708_rng_init);
169 +module_exit(bcm2708_rng_exit);
171 +MODULE_DESCRIPTION("BCM2708 H/W Random Number Generator (RNG) driver");
172 +MODULE_LICENSE("GPL and additional rights");