131 lines
3.4 KiB
C
131 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Ingenic True Random Number Generator driver
|
|
* Copyright (c) 2019 漆鹏振 (Qi Pengzhen) <aric.pzqi@ingenic.com>
|
|
* Copyright (c) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/err.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/hw_random.h>
|
|
#include <linux/io.h>
|
|
#include <linux/iopoll.h>
|
|
#include <linux/mod_devicetable.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/slab.h>
|
|
|
|
/* DTRNG register offsets */
|
|
#define TRNG_REG_CFG_OFFSET 0x00
|
|
#define TRNG_REG_RANDOMNUM_OFFSET 0x04
|
|
#define TRNG_REG_STATUS_OFFSET 0x08
|
|
|
|
/* bits within the CFG register */
|
|
#define CFG_GEN_EN BIT(0)
|
|
|
|
/* bits within the STATUS register */
|
|
#define STATUS_RANDOM_RDY BIT(0)
|
|
|
|
struct ingenic_trng {
|
|
void __iomem *base;
|
|
struct hwrng rng;
|
|
};
|
|
|
|
static int ingenic_trng_init(struct hwrng *rng)
|
|
{
|
|
struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng);
|
|
unsigned int ctrl;
|
|
|
|
ctrl = readl(trng->base + TRNG_REG_CFG_OFFSET);
|
|
ctrl |= CFG_GEN_EN;
|
|
writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void ingenic_trng_cleanup(struct hwrng *rng)
|
|
{
|
|
struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng);
|
|
unsigned int ctrl;
|
|
|
|
ctrl = readl(trng->base + TRNG_REG_CFG_OFFSET);
|
|
ctrl &= ~CFG_GEN_EN;
|
|
writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET);
|
|
}
|
|
|
|
static int ingenic_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
|
|
{
|
|
struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng);
|
|
u32 *data = buf;
|
|
u32 status;
|
|
int ret;
|
|
|
|
ret = readl_poll_timeout(trng->base + TRNG_REG_STATUS_OFFSET, status,
|
|
status & STATUS_RANDOM_RDY, 10, 1000);
|
|
if (ret == -ETIMEDOUT) {
|
|
pr_err("%s: Wait for DTRNG data ready timeout\n", __func__);
|
|
return ret;
|
|
}
|
|
|
|
*data = readl(trng->base + TRNG_REG_RANDOMNUM_OFFSET);
|
|
|
|
return 4;
|
|
}
|
|
|
|
static int ingenic_trng_probe(struct platform_device *pdev)
|
|
{
|
|
struct ingenic_trng *trng;
|
|
struct clk *clk;
|
|
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 dev_err_probe(&pdev->dev, PTR_ERR(trng->base),
|
|
"%s: Failed to map DTRNG registers\n", __func__);
|
|
|
|
clk = devm_clk_get_enabled(&pdev->dev, NULL);
|
|
if (IS_ERR(clk))
|
|
return dev_err_probe(&pdev->dev, PTR_ERR(clk),
|
|
"%s: Cannot get and enable DTRNG clock\n", __func__);
|
|
|
|
trng->rng.name = pdev->name;
|
|
trng->rng.init = ingenic_trng_init;
|
|
trng->rng.cleanup = ingenic_trng_cleanup;
|
|
trng->rng.read = ingenic_trng_read;
|
|
|
|
ret = devm_hwrng_register(&pdev->dev, &trng->rng);
|
|
if (ret)
|
|
return dev_err_probe(&pdev->dev, ret, "Failed to register hwrng\n");
|
|
|
|
platform_set_drvdata(pdev, trng);
|
|
|
|
dev_info(&pdev->dev, "Ingenic DTRNG driver registered\n");
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id ingenic_trng_of_match[] = {
|
|
{ .compatible = "ingenic,x1830-dtrng" },
|
|
{ /* sentinel */ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, ingenic_trng_of_match);
|
|
|
|
static struct platform_driver ingenic_trng_driver = {
|
|
.probe = ingenic_trng_probe,
|
|
.driver = {
|
|
.name = "ingenic-trng",
|
|
.of_match_table = ingenic_trng_of_match,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(ingenic_trng_driver);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("漆鹏振 (Qi Pengzhen) <aric.pzqi@ingenic.com>");
|
|
MODULE_AUTHOR("周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>");
|
|
MODULE_DESCRIPTION("Ingenic True Random Number Generator driver");
|