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
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
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
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
34 +config HW_RANDOM_BCM2708
35 + tristate "BCM2708 generic true random number generator support"
36 + depends on HW_RANDOM && ARCH_BCM2708
38 + This driver provides the kernel-side support for the BCM2708 hardware.
40 + To compile this driver as a module, choose M here: the
41 + module will be called bcm2708-rng.
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
60 index 0000000..1ffa7d7
62 +++ b/drivers/char/hw_random/bcm2708-rng.c
65 + * Copyright (c) 2010-2012 Broadcom. All rights reserved.
67 + * Redistribution and use in source and binary forms, with or without
68 + * modification, are permitted provided that the following conditions
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.
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.
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.
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>
104 +#include <mach/hardware.h>
105 +#include <mach/platform.h>
107 +#define RNG_CTRL (0x0)
108 +#define RNG_STATUS (0x4)
109 +#define RNG_DATA (0x8)
110 +#define RNG_FF_THRESHOLD (0xc)
113 +#define RNG_RBGEN 0x1
114 +/* double speed, less random mode */
115 +#define RNG_RBG2X 0x2
117 +/* the initial numbers generated are "less random" so will be discarded */
118 +#define RNG_WARMUP_COUNT 0x40000
120 +static int bcm2708_rng_data_read(struct hwrng *rng, u32 *buffer)
122 + void __iomem *rng_base = (void __iomem *)rng->priv;
124 + /* wait for a random number to be in fifo */
126 + words = __raw_readl(rng_base + RNG_STATUS)>>24;
128 + while (words == 0);
129 + /* read the random number */
130 + *buffer = __raw_readl(rng_base + RNG_DATA);
134 +static struct hwrng bcm2708_rng_ops = {
136 + .data_read = bcm2708_rng_data_read,
139 +static int __init bcm2708_rng_init(void)
141 + void __iomem *rng_base;
144 + /* map peripheral */
145 + rng_base = ioremap(RNG_BASE, 0x10);
146 + pr_info("bcm2708_rng_init=%p\n", rng_base);
148 + pr_err("bcm2708_rng_init failed to ioremap\n");
151 + bcm2708_rng_ops.priv = (unsigned long)rng_base;
152 + /* register driver */
153 + err = hwrng_register(&bcm2708_rng_ops);
155 + pr_err("bcm2708_rng_init hwrng_register()=%d\n", err);
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);
165 +static void __exit bcm2708_rng_exit(void)
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);
176 +module_init(bcm2708_rng_init);
177 +module_exit(bcm2708_rng_exit);
179 +MODULE_DESCRIPTION("BCM2708 H/W Random Number Generator (RNG) driver");
180 +MODULE_LICENSE("GPL and additional rights");