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/*
* Hardware Random Number Generator support for Cavium Networks
* Octeon processor family.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2009 Cavium Networks
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/hw_random.h>
#include <linux/io.h>
#include <linux/gfp.h>
#include <asm/octeon/octeon.h>
#include <asm/octeon/cvmx-rnm-defs.h>
struct octeon_rng {
struct hwrng ops;
void __iomem *control_status;
void __iomem *result;
};
static int octeon_rng_init(struct hwrng *rng)
{
union cvmx_rnm_ctl_status ctl;
struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
ctl.u64 = 0;
ctl.s.ent_en = 1; /* Enable the entropy source. */
ctl.s.rng_en = 1; /* Enable the RNG hardware. */
cvmx_write_csr((__force u64)p->control_status, ctl.u64);
return 0;
}
static void octeon_rng_cleanup(struct hwrng *rng)
{
union cvmx_rnm_ctl_status ctl;
struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
ctl.u64 = 0;
/* Disable everything. */
cvmx_write_csr((__force u64)p->control_status, ctl.u64);
}
static int octeon_rng_data_read(struct hwrng *rng, u32 *data)
{
struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
*data = cvmx_read64_uint32((__force u64)p->result);
return sizeof(u32);
}
static int octeon_rng_probe(struct platform_device *pdev)
{
struct resource *res_ports;
struct resource *res_result;
struct octeon_rng *rng;
int ret;
struct hwrng ops = {
.name = "octeon",
.init = octeon_rng_init,
.cleanup = octeon_rng_cleanup,
.data_read = octeon_rng_data_read
};
rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
if (!rng)
return -ENOMEM;
res_ports = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res_ports)
return -ENOENT;
res_result = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!res_result)
return -ENOENT;
rng->control_status = devm_ioremap(&pdev->dev,
res_ports->start,
sizeof(u64));
if (!rng->control_status)
return -ENOENT;
rng->result = devm_ioremap(&pdev->dev,
res_result->start,
sizeof(u64));
if (!rng->result)
return -ENOENT;
rng->ops = ops;
platform_set_drvdata(pdev, &rng->ops);
ret = devm_hwrng_register(&pdev->dev, &rng->ops);
if (ret)
return -ENOENT;
dev_info(&pdev->dev, "Octeon Random Number Generator\n");
return 0;
}
static struct platform_driver octeon_rng_driver = {
.driver = {
.name = "octeon_rng",
},
.probe = octeon_rng_probe,
};
module_platform_driver(octeon_rng_driver);
MODULE_AUTHOR("David Daney");
MODULE_LICENSE("GPL");
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