Commit 3e90efd1 authored by Zaibo Xu's avatar Zaibo Xu Committed by Herbert Xu
Browse files

hwrng: hisi - add HiSilicon TRNG driver support 



This series adds HiSilicon true random number generator(TRNG)
driver in hw_random subsystem.

Signed-off-by: default avatarZaibo Xu <xuzaibo@huawei.com>
Signed-off-by: default avatarWeili Qian <qianweili@huawei.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent a9704293

drivers/char/hw_random/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -308,6 +308,19 @@ config HW_RANDOM_HISI 


	  If unsure, say Y.



config HW_RANDOM_HISI_V2

	tristate "HiSilicon True Random Number Generator V2 support"

	depends on HW_RANDOM && ARM64 && ACPI

	default HW_RANDOM

	help

	  This driver provides kernel-side support for the True Random Number

	  Generator V2 hardware found on HiSilicon Hi1620 SoC.



	  To compile this driver as a module, choose M here: the

	  module will be called hisi-trng-v2.



	  If unsure, say Y.



config HW_RANDOM_ST

	tristate "ST Microelectronics HW Random Number Generator support"

	depends on HW_RANDOM && ARCH_STI

drivers/char/hw_random/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o 
obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o

obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o

obj-$(CONFIG_HW_RANDOM_HISI)	+= hisi-rng.o

obj-$(CONFIG_HW_RANDOM_HISI_V2) += hisi-trng-v2.o

obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o

obj-$(CONFIG_HW_RANDOM_IPROC_RNG200) += iproc-rng200.o

obj-$(CONFIG_HW_RANDOM_ST) += st-rng.o

drivers/char/hw_random/hisi-trng-v2.c

0 → 100644
+99 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2019 HiSilicon Limited. */



#include <linux/acpi.h>

#include <linux/err.h>

#include <linux/hw_random.h>

#include <linux/io.h>

#include <linux/iopoll.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/random.h>



#define HISI_TRNG_REG		0x00F0

#define HISI_TRNG_BYTES		4

#define HISI_TRNG_QUALITY	512

#define SLEEP_US		10

#define TIMEOUT_US		10000



struct hisi_trng {

	void __iomem *base;

	struct hwrng rng;

};



static int hisi_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)

{

	struct hisi_trng *trng;

	int currsize = 0;

	u32 val = 0;

	u32 ret;



	trng = container_of(rng, struct hisi_trng, rng);



	do {

		ret = readl_poll_timeout(trng->base + HISI_TRNG_REG, val,

					 val, SLEEP_US, TIMEOUT_US);

		if (ret)

			return currsize;



		if (max - currsize >= HISI_TRNG_BYTES) {

			memcpy(buf + currsize, &val, HISI_TRNG_BYTES);

			currsize += HISI_TRNG_BYTES;

			if (currsize == max)

				return currsize;

			continue;

		}



		/* copy remaining bytes */

		memcpy(buf + currsize, &val, max - currsize);

		currsize = max;

	} while (currsize < max);



	return currsize;

}



static int hisi_trng_probe(struct platform_device *pdev)

{

	struct hisi_trng *trng;

	int ret;



	trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);

	if (!trng)

		return -ENOMEM;



	trng->base = devm_platform_ioremap_resource(pdev, 0);

	if (IS_ERR(trng->base))

		return PTR_ERR(trng->base);



	trng->rng.name = pdev->name;

	trng->rng.read = hisi_trng_read;

	trng->rng.quality = HISI_TRNG_QUALITY;



	ret = devm_hwrng_register(&pdev->dev, &trng->rng);

	if (ret)

		dev_err(&pdev->dev, "failed to register hwrng!\n");



	return ret;

}



static const struct acpi_device_id hisi_trng_acpi_match[] = {

	{ "HISI02B3", 0 },

	{ }

};

MODULE_DEVICE_TABLE(acpi, hisi_trng_acpi_match);



static struct platform_driver hisi_trng_driver = {

	.probe		= hisi_trng_probe,

	.driver		= {

		.name	= "hisi-trng-v2",

		.acpi_match_table = ACPI_PTR(hisi_trng_acpi_match),

	},

};



module_platform_driver(hisi_trng_driver);



MODULE_LICENSE("GPL v2");

MODULE_AUTHOR("Weili Qian <qianweili@huawei.com>");

MODULE_AUTHOR("Zaibo Xu <xuzaibo@huawei.com>");

MODULE_DESCRIPTION("HiSilicon true random number generator V2 driver");