diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/char/hw_random/bcm2835-rng.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/char/hw_random/bcm2835-rng.c')
-rw-r--r-- | kernel/drivers/char/hw_random/bcm2835-rng.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/kernel/drivers/char/hw_random/bcm2835-rng.c b/kernel/drivers/char/hw_random/bcm2835-rng.c new file mode 100644 index 000000000..7192ec25f --- /dev/null +++ b/kernel/drivers/char/hw_random/bcm2835-rng.c @@ -0,0 +1,111 @@ +/** + * Copyright (c) 2010-2012 Broadcom. All rights reserved. + * Copyright (c) 2013 Lubomir Rintel + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License ("GPL") + * version 2, as published by the Free Software Foundation. + */ + +#include <linux/hw_random.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/printk.h> + +#define RNG_CTRL 0x0 +#define RNG_STATUS 0x4 +#define RNG_DATA 0x8 + +/* enable rng */ +#define RNG_RBGEN 0x1 + +/* the initial numbers generated are "less random" so will be discarded */ +#define RNG_WARMUP_COUNT 0x40000 + +static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max, + bool wait) +{ + void __iomem *rng_base = (void __iomem *)rng->priv; + + while ((__raw_readl(rng_base + RNG_STATUS) >> 24) == 0) { + if (!wait) + return 0; + cpu_relax(); + } + + *(u32 *)buf = __raw_readl(rng_base + RNG_DATA); + return sizeof(u32); +} + +static struct hwrng bcm2835_rng_ops = { + .name = "bcm2835", + .read = bcm2835_rng_read, +}; + +static int bcm2835_rng_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + void __iomem *rng_base; + int err; + + /* map peripheral */ + rng_base = of_iomap(np, 0); + if (!rng_base) { + dev_err(dev, "failed to remap rng regs"); + return -ENODEV; + } + bcm2835_rng_ops.priv = (unsigned long)rng_base; + + /* set warm-up count & enable */ + __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS); + __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL); + + /* register driver */ + err = hwrng_register(&bcm2835_rng_ops); + if (err) { + dev_err(dev, "hwrng registration failed\n"); + iounmap(rng_base); + } else + dev_info(dev, "hwrng registered\n"); + + return err; +} + +static int bcm2835_rng_remove(struct platform_device *pdev) +{ + void __iomem *rng_base = (void __iomem *)bcm2835_rng_ops.priv; + + /* disable rng hardware */ + __raw_writel(0, rng_base + RNG_CTRL); + + /* unregister driver */ + hwrng_unregister(&bcm2835_rng_ops); + iounmap(rng_base); + + return 0; +} + +static const struct of_device_id bcm2835_rng_of_match[] = { + { .compatible = "brcm,bcm2835-rng", }, + {}, +}; +MODULE_DEVICE_TABLE(of, bcm2835_rng_of_match); + +static struct platform_driver bcm2835_rng_driver = { + .driver = { + .name = "bcm2835-rng", + .of_match_table = bcm2835_rng_of_match, + }, + .probe = bcm2835_rng_probe, + .remove = bcm2835_rng_remove, +}; +module_platform_driver(bcm2835_rng_driver); + +MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>"); +MODULE_DESCRIPTION("BCM2835 Random Number Generator (RNG) driver"); +MODULE_LICENSE("GPL v2"); |