[PATCH v3 2/2] hwrng: hisi: Add support for Hisilicon SoC RNG
Mathieu Poirier
mathieu.poirier at linaro.org
Mon Apr 11 08:29:22 PDT 2016
On 10 April 2016 at 21:01, Kefeng Wang <wangkefeng.wang at huawei.com> wrote:
> This adds the Hisilicon Random Number Generator(RNG) support,
> which is found in Hip04 and Hip05 soc.
>
> Signed-off-by: Kefeng Wang <wangkefeng.wang at huawei.com>
> ---
> drivers/char/hw_random/Kconfig | 13 ++++
> drivers/char/hw_random/Makefile | 1 +
> drivers/char/hw_random/hisi-rng.c | 125 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 139 insertions(+)
> create mode 100644 drivers/char/hw_random/hisi-rng.c
>
> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
> index 67ee8b0..088b1bf 100644
> --- a/drivers/char/hw_random/Kconfig
> +++ b/drivers/char/hw_random/Kconfig
> @@ -333,6 +333,19 @@ 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
> diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
> index f5a6fa7..e09305b 100644
> --- a/drivers/char/hw_random/Makefile
> +++ b/drivers/char/hw_random/Makefile
> @@ -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
> diff --git a/drivers/char/hw_random/hisi-rng.c b/drivers/char/hw_random/hisi-rng.c
> new file mode 100644
> index 0000000..6bdf28c
> --- /dev/null
> +++ b/drivers/char/hw_random/hisi-rng.c
> @@ -0,0 +1,125 @@
> +/*
> + * 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,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 at huawei>");
> +MODULE_DESCRIPTION("Hisilicon random number generator driver");
Thanks for the modifications,
Reviewed-by: Mathieu Poirier <mathieu.poirier at linaro.org>
> --
> 1.7.12.4
>
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