hwrng: hisi - Add support for Hisilicon SoC RNG

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>
This commit is contained in:
Kefeng Wang 2016-04-13 18:11:28 +08:00 committed by Herbert Xu
parent c7995ee7ff
commit afc39d6e89
3 changed files with 140 additions and 0 deletions

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@ -334,6 +334,19 @@ config HW_RANDOM_TPM
If unsure, say Y.
config HW_RANDOM_HISI
tristate "Hisilicon Random Number Generator support"
depends on HW_RANDOM && ARCH_HISI
default HW_RANDOM
---help---
This driver provides kernel-side support for the Random Number
Generator hardware found on Hisilicon Hip04 and Hip05 SoC.
To compile this driver as a module, choose M here: the
module will be called hisi-rng.
If unsure, say Y.
config HW_RANDOM_MSM
tristate "Qualcomm SoCs Random Number Generator support"
depends on HW_RANDOM && ARCH_QCOM

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@ -26,6 +26,7 @@ obj-$(CONFIG_HW_RANDOM_PPC4XX) += ppc4xx-rng.o
obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o
obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o
obj-$(CONFIG_HW_RANDOM_HISI) += hisi-rng.o
obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o
obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
obj-$(CONFIG_HW_RANDOM_IPROC_RNG200) += iproc-rng200.o

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@ -0,0 +1,126 @@
/*
* 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");