mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-04 18:09:57 +00:00
![Zaibo Xu](/assets/img/avatar_default.png)
This series adds HiSilicon true random number generator(TRNG) driver in hw_random subsystem. Signed-off-by: Zaibo Xu <xuzaibo@huawei.com> Signed-off-by: Weili Qian <qianweili@huawei.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
99 lines
2.2 KiB
C
99 lines
2.2 KiB
C
// 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");
|