mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-26 21:15:11 +07:00
afc39d6e89
This adds the Hisilicon Random Number Generator(RNG) support, which is found in Hip04 and Hip05 soc. Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
127 lines
2.9 KiB
C
127 lines
2.9 KiB
C
/*
|
|
* Copyright (C) 2016 HiSilicon Co., Ltd.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/err.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/hw_random.h>
|
|
#include <linux/io.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/random.h>
|
|
|
|
#define RNG_SEED 0x0
|
|
#define RNG_CTRL 0x4
|
|
#define RNG_SEED_SEL BIT(2)
|
|
#define RNG_RING_EN BIT(1)
|
|
#define RNG_EN BIT(0)
|
|
#define RNG_RAN_NUM 0x10
|
|
#define RNG_PHY_SEED 0x14
|
|
|
|
#define to_hisi_rng(p) container_of(p, struct hisi_rng, rng)
|
|
|
|
static int seed_sel;
|
|
module_param(seed_sel, int, S_IRUGO);
|
|
MODULE_PARM_DESC(seed_sel, "Auto reload seed. 0, use LFSR(default); 1, use ring oscillator.");
|
|
|
|
struct hisi_rng {
|
|
void __iomem *base;
|
|
struct hwrng rng;
|
|
};
|
|
|
|
static int hisi_rng_init(struct hwrng *rng)
|
|
{
|
|
struct hisi_rng *hrng = to_hisi_rng(rng);
|
|
int val = RNG_EN;
|
|
u32 seed;
|
|
|
|
/* get a random number as initial seed */
|
|
get_random_bytes(&seed, sizeof(seed));
|
|
|
|
writel_relaxed(seed, hrng->base + RNG_SEED);
|
|
|
|
/**
|
|
* The seed is reload periodically, there are two choice
|
|
* of seeds, default seed using the value from LFSR, or
|
|
* will use seed generated by ring oscillator.
|
|
*/
|
|
if (seed_sel == 1)
|
|
val |= RNG_RING_EN | RNG_SEED_SEL;
|
|
|
|
writel_relaxed(val, hrng->base + RNG_CTRL);
|
|
return 0;
|
|
}
|
|
|
|
static void hisi_rng_cleanup(struct hwrng *rng)
|
|
{
|
|
struct hisi_rng *hrng = to_hisi_rng(rng);
|
|
|
|
writel_relaxed(0, hrng->base + RNG_CTRL);
|
|
}
|
|
|
|
static int hisi_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
|
|
{
|
|
struct hisi_rng *hrng = to_hisi_rng(rng);
|
|
u32 *data = buf;
|
|
|
|
*data = readl_relaxed(hrng->base + RNG_RAN_NUM);
|
|
return 4;
|
|
}
|
|
|
|
static int hisi_rng_probe(struct platform_device *pdev)
|
|
{
|
|
struct hisi_rng *rng;
|
|
struct resource *res;
|
|
int ret;
|
|
|
|
rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
|
|
if (!rng)
|
|
return -ENOMEM;
|
|
|
|
platform_set_drvdata(pdev, rng);
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
rng->base = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(rng->base))
|
|
return PTR_ERR(rng->base);
|
|
|
|
rng->rng.name = pdev->name;
|
|
rng->rng.init = hisi_rng_init;
|
|
rng->rng.cleanup = hisi_rng_cleanup;
|
|
rng->rng.read = hisi_rng_read;
|
|
|
|
ret = devm_hwrng_register(&pdev->dev, &rng->rng);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "failed to register hwrng\n");
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id hisi_rng_dt_ids[] = {
|
|
{ .compatible = "hisilicon,hip04-rng" },
|
|
{ .compatible = "hisilicon,hip05-rng" },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, hisi_rng_dt_ids);
|
|
|
|
static struct platform_driver hisi_rng_driver = {
|
|
.probe = hisi_rng_probe,
|
|
.driver = {
|
|
.name = "hisi-rng",
|
|
.of_match_table = of_match_ptr(hisi_rng_dt_ids),
|
|
},
|
|
};
|
|
|
|
module_platform_driver(hisi_rng_driver);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Kefeng Wang <wangkefeng.wang@huawei>");
|
|
MODULE_DESCRIPTION("Hisilicon random number generator driver");
|