hwrng: nomadik - Add hardware RNG driver (bc85b25e) · Commits · e / devices / android_kernel_teracube_emerald

drivers/char/hw_random/Kconfig

+12 −0

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		@@ -186,3 +186,15 @@ config HW_RANDOM_MXC_RNGA
		module will be called mxc-rnga.

		If unsure, say Y.

		config HW_RANDOM_NOMADIK
		tristate "ST-Ericsson Nomadik Random Number Generator support"
		depends on HW_RANDOM && PLAT_NOMADIK
		---help---
		This driver provides kernel-side support for the Random Number
		Generator hardware found on ST-Ericsson SoCs (8815 and 8500).

		To compile this driver as a module, choose M here: the
		module will be called nomadik-rng.

		If unsure, say Y.

drivers/char/hw_random/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -18,3 +18,4 @@ obj-$(CONFIG_HW_RANDOM_VIRTIO) += virtio-rng.o
		obj-$(CONFIG_HW_RANDOM_TX4939) += tx4939-rng.o
		obj-$(CONFIG_HW_RANDOM_MXC_RNGA) += mxc-rnga.o
		obj-$(CONFIG_HW_RANDOM_OCTEON) += octeon-rng.o
		obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o

drivers/char/hw_random/nomadik-rng.c

0 → 100644

+103 −0

Original line number	Diff line number	Diff line
		/*
		* Nomadik RNG support
		* Copyright 2009 Alessandro Rubini
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*/

		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/init.h>
		#include <linux/device.h>
		#include <linux/amba/bus.h>
		#include <linux/hw_random.h>
		#include <linux/io.h>

		static int nmk_rng_read(struct hwrng rng, void data, size_t max, bool wait)
		{
		void __iomem base = (void __iomem )rng->priv;

		/*
		* The register is 32 bits and gives 16 random bits (low half).
		* A subsequent read will delay the core for 400ns, so we just read
		* once and accept the very unlikely very small delay, even if wait==0.
		*/
		(u16 )data = __raw_readl(base + 8) & 0xffff;
		return 2;
		}

		/* we have at most one RNG per machine, granted */
		static struct hwrng nmk_rng = {
		.name = "nomadik",
		.read = nmk_rng_read,
		};

		static int nmk_rng_probe(struct amba_device dev, struct amba_id id)
		{
		void __iomem *base;
		int ret;

		ret = amba_request_regions(dev, dev->dev.init_name);
		if (ret)
		return ret;
		ret = -ENOMEM;
		base = ioremap(dev->res.start, resource_size(&dev->res));
		if (!base)
		goto out_release;
		nmk_rng.priv = (unsigned long)base;
		ret = hwrng_register(&nmk_rng);
		if (ret)
		goto out_unmap;
		return 0;

		out_unmap:
		iounmap(base);
		out_release:
		amba_release_regions(dev);
		return ret;
		}

		static int nmk_rng_remove(struct amba_device *dev)
		{
		void __iomem base = (void __iomem )nmk_rng.priv;
		hwrng_unregister(&nmk_rng);
		iounmap(base);
		amba_release_regions(dev);
		return 0;
		}

		static struct amba_id nmk_rng_ids[] = {
		{
		.id = 0x000805e1,
		.mask = 0x000fffff, /* top bits are rev and cfg: accept all */
		},
		{0, 0},
		};

		static struct amba_driver nmk_rng_driver = {
		.drv = {
		.owner = THIS_MODULE,
		.name = "rng",
		},
		.probe = nmk_rng_probe,
		.remove = nmk_rng_remove,
		.id_table = nmk_rng_ids,
		};

		static int __init nmk_rng_init(void)
		{
		return amba_driver_register(&nmk_rng_driver);
		}

		static void __devexit nmk_rng_exit(void)
		{
		amba_driver_unregister(&nmk_rng_driver);
		}

		module_init(nmk_rng_init);
		module_exit(nmk_rng_exit);

		MODULE_LICENSE("GPL");