From 1ecfdf8a7a08d52d238dc132c85d37966ca58737 Mon Sep 17 00:00:00 2001 From: popcornmix Date: Wed, 3 Jul 2013 00:51:55 +0100 Subject: [PATCH 047/196] Add hwrng (hardware random number generator) driver --- arch/arm/mach-bcm2708/include/mach/platform.h | 1 + drivers/char/hw_random/Kconfig | 12 +++ drivers/char/hw_random/Makefile | 1 + drivers/char/hw_random/bcm2708-rng.c | 117 ++++++++++++++++++++++++++ 4 files changed, 131 insertions(+) create mode 100755 drivers/char/hw_random/bcm2708-rng.c diff --git a/arch/arm/mach-bcm2708/include/mach/platform.h b/arch/arm/mach-bcm2708/include/mach/platform.h index 89e72d1..992a630 100644 --- a/arch/arm/mach-bcm2708/include/mach/platform.h +++ b/arch/arm/mach-bcm2708/include/mach/platform.h @@ -62,6 +62,7 @@ #define DMA_BASE (BCM2708_PERI_BASE + 0x7000) /* DMA controller */ #define ARM_BASE (BCM2708_PERI_BASE + 0xB000) /* BCM2708 ARM control block */ #define PM_BASE (BCM2708_PERI_BASE + 0x100000) /* Power Management, Reset controller and Watchdog registers */ +#define RNG_BASE (BCM2708_PERI_BASE + 0x104000) /* Hardware RNG */ #define GPIO_BASE (BCM2708_PERI_BASE + 0x200000) /* GPIO */ #define UART0_BASE (BCM2708_PERI_BASE + 0x201000) /* Uart 0 */ #define MMCI0_BASE (BCM2708_PERI_BASE + 0x202000) /* MMC interface */ diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 2f9dbf7..d725a53 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -314,3 +314,15 @@ config HW_RANDOM_TPM module will be called tpm-rng. If unsure, say Y. + +config HW_RANDOM_BCM2708 + tristate "BCM2708 generic true random number generator support" + depends on HW_RANDOM && ARCH_BCM2708 + ---help--- + This driver provides the kernel-side support for the BCM2708 hardware. + + To compile this driver as a module, choose M here: the + module will be called bcm2708-rng. + + If unsure, say N. + diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index bed467c..18fc4d4 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -27,3 +27,4 @@ obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o +obj-$(CONFIG_HW_RANDOM_BCM2708) += bcm2708-rng.o diff --git a/drivers/char/hw_random/bcm2708-rng.c b/drivers/char/hw_random/bcm2708-rng.c new file mode 100755 index 0000000..1ffa7d7 --- /dev/null +++ b/drivers/char/hw_random/bcm2708-rng.c @@ -0,0 +1,117 @@ +/** + * Copyright (c) 2010-2012 Broadcom. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions, and the following disclaimer, + * without modification. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The names of the above-listed copyright holders may not be used + * to endorse or promote products derived from this software without + * specific prior written permission. + * + * ALTERNATIVELY, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2, as published by the Free + * Software Foundation. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include +#include +#include + +#include +#include +#include + +#define RNG_CTRL (0x0) +#define RNG_STATUS (0x4) +#define RNG_DATA (0x8) +#define RNG_FF_THRESHOLD (0xc) + +/* enable rng */ +#define RNG_RBGEN 0x1 +/* double speed, less random mode */ +#define RNG_RBG2X 0x2 + +/* the initial numbers generated are "less random" so will be discarded */ +#define RNG_WARMUP_COUNT 0x40000 + +static int bcm2708_rng_data_read(struct hwrng *rng, u32 *buffer) +{ + void __iomem *rng_base = (void __iomem *)rng->priv; + unsigned words; + /* wait for a random number to be in fifo */ + do { + words = __raw_readl(rng_base + RNG_STATUS)>>24; + } + while (words == 0); + /* read the random number */ + *buffer = __raw_readl(rng_base + RNG_DATA); + return 4; +} + +static struct hwrng bcm2708_rng_ops = { + .name = "bcm2708", + .data_read = bcm2708_rng_data_read, +}; + +static int __init bcm2708_rng_init(void) +{ + void __iomem *rng_base; + int err; + + /* map peripheral */ + rng_base = ioremap(RNG_BASE, 0x10); + pr_info("bcm2708_rng_init=%p\n", rng_base); + if (!rng_base) { + pr_err("bcm2708_rng_init failed to ioremap\n"); + return -ENOMEM; + } + bcm2708_rng_ops.priv = (unsigned long)rng_base; + /* register driver */ + err = hwrng_register(&bcm2708_rng_ops); + if (err) { + pr_err("bcm2708_rng_init hwrng_register()=%d\n", err); + iounmap(rng_base); + } else { + /* set warm-up count & enable */ + __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS); + __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL); + } + return err; +} + +static void __exit bcm2708_rng_exit(void) +{ + void __iomem *rng_base = (void __iomem *)bcm2708_rng_ops.priv; + pr_info("bcm2708_rng_exit\n"); + /* disable rng hardware */ + __raw_writel(0, rng_base + RNG_CTRL); + /* unregister driver */ + hwrng_unregister(&bcm2708_rng_ops); + iounmap(rng_base); +} + +module_init(bcm2708_rng_init); +module_exit(bcm2708_rng_exit); + +MODULE_DESCRIPTION("BCM2708 H/W Random Number Generator (RNG) driver"); +MODULE_LICENSE("GPL and additional rights"); -- 1.9.1