hwrng: hisi - Add support for Hisilicon SoC RNG (afc39d6e) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/char/hw_random/Kconfig

+13 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/char/hw_random/Makefile

+1 −0

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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

drivers/char/hw_random/hisi-rng.c

0 → 100644

+126 −0

Original line number	Diff line number	Diff line
		/*
		* 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");