Orange Pi5 kernel

// 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");