android_kernel_xiaomi_sm8350/drivers/char/hw_random/octeon-rng.c
David Daney f7557dc821 MIPS: hw_random: Add hardware RNG for Octeon SOCs.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-09-17 20:07:51 +02:00

148 lines
3.2 KiB
C

/*
* 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/init.h>
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/hw_random.h>
#include <linux/io.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((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((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((u64)p->result);
return sizeof(u32);
}
static int __devinit 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)
goto err_ports;
res_result = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!res_result)
goto err_ports;
rng->control_status = devm_ioremap_nocache(&pdev->dev,
res_ports->start,
sizeof(u64));
if (!rng->control_status)
goto err_ports;
rng->result = devm_ioremap_nocache(&pdev->dev,
res_result->start,
sizeof(u64));
if (!rng->result)
goto err_r;
rng->ops = ops;
dev_set_drvdata(&pdev->dev, &rng->ops);
ret = hwrng_register(&rng->ops);
if (ret)
goto err;
dev_info(&pdev->dev, "Octeon Random Number Generator\n");
return 0;
err:
devm_iounmap(&pdev->dev, rng->control_status);
err_r:
devm_iounmap(&pdev->dev, rng->result);
err_ports:
devm_kfree(&pdev->dev, rng);
return -ENOENT;
}
static int __exit octeon_rng_remove(struct platform_device *pdev)
{
struct hwrng *rng = dev_get_drvdata(&pdev->dev);
hwrng_unregister(rng);
return 0;
}
static struct platform_driver octeon_rng_driver = {
.driver = {
.name = "octeon_rng",
.owner = THIS_MODULE,
},
.probe = octeon_rng_probe,
.remove = __exit_p(octeon_rng_remove),
};
static int __init octeon_rng_mod_init(void)
{
return platform_driver_register(&octeon_rng_driver);
}
static void __exit octeon_rng_mod_exit(void)
{
platform_driver_unregister(&octeon_rng_driver);
}
module_init(octeon_rng_mod_init);
module_exit(octeon_rng_mod_exit);
MODULE_AUTHOR("David Daney");
MODULE_LICENSE("GPL");