![weiyongjun \(A\)](/assets/img/avatar_default.png)
There is a error message within devm_ioremap_resource already, so remove the dev_err call to avoid redundant error message. Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: Łukasz Stelmach <l.stelmach@samsung.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
236 lines
5.4 KiB
C
236 lines
5.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* RNG driver for Exynos TRNGs
|
|
*
|
|
* Author: Łukasz Stelmach <l.stelmach@samsung.com>
|
|
*
|
|
* Copyright 2017 (c) Samsung Electronics Software, Inc.
|
|
*
|
|
* Based on the Exynos PRNG driver drivers/crypto/exynos-rng by
|
|
* Krzysztof Kozłowski <krzk@kernel.org>
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/crypto.h>
|
|
#include <linux/delay.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/pm_runtime.h>
|
|
|
|
#define EXYNOS_TRNG_CLKDIV (0x0)
|
|
|
|
#define EXYNOS_TRNG_CTRL (0x20)
|
|
#define EXYNOS_TRNG_CTRL_RNGEN BIT(31)
|
|
|
|
#define EXYNOS_TRNG_POST_CTRL (0x30)
|
|
#define EXYNOS_TRNG_ONLINE_CTRL (0x40)
|
|
#define EXYNOS_TRNG_ONLINE_STAT (0x44)
|
|
#define EXYNOS_TRNG_ONLINE_MAXCHI2 (0x48)
|
|
#define EXYNOS_TRNG_FIFO_CTRL (0x50)
|
|
#define EXYNOS_TRNG_FIFO_0 (0x80)
|
|
#define EXYNOS_TRNG_FIFO_1 (0x84)
|
|
#define EXYNOS_TRNG_FIFO_2 (0x88)
|
|
#define EXYNOS_TRNG_FIFO_3 (0x8c)
|
|
#define EXYNOS_TRNG_FIFO_4 (0x90)
|
|
#define EXYNOS_TRNG_FIFO_5 (0x94)
|
|
#define EXYNOS_TRNG_FIFO_6 (0x98)
|
|
#define EXYNOS_TRNG_FIFO_7 (0x9c)
|
|
#define EXYNOS_TRNG_FIFO_LEN (8)
|
|
#define EXYNOS_TRNG_CLOCK_RATE (500000)
|
|
|
|
|
|
struct exynos_trng_dev {
|
|
struct device *dev;
|
|
void __iomem *mem;
|
|
struct clk *clk;
|
|
struct hwrng rng;
|
|
};
|
|
|
|
static int exynos_trng_do_read(struct hwrng *rng, void *data, size_t max,
|
|
bool wait)
|
|
{
|
|
struct exynos_trng_dev *trng;
|
|
int val;
|
|
|
|
max = min_t(size_t, max, (EXYNOS_TRNG_FIFO_LEN * 4));
|
|
|
|
trng = (struct exynos_trng_dev *)rng->priv;
|
|
|
|
writel_relaxed(max * 8, trng->mem + EXYNOS_TRNG_FIFO_CTRL);
|
|
val = readl_poll_timeout(trng->mem + EXYNOS_TRNG_FIFO_CTRL, val,
|
|
val == 0, 200, 1000000);
|
|
if (val < 0)
|
|
return val;
|
|
|
|
memcpy_fromio(data, trng->mem + EXYNOS_TRNG_FIFO_0, max);
|
|
|
|
return max;
|
|
}
|
|
|
|
static int exynos_trng_init(struct hwrng *rng)
|
|
{
|
|
struct exynos_trng_dev *trng = (struct exynos_trng_dev *)rng->priv;
|
|
unsigned long sss_rate;
|
|
u32 val;
|
|
|
|
sss_rate = clk_get_rate(trng->clk);
|
|
|
|
/*
|
|
* For most TRNG circuits the clock frequency of under 500 kHz
|
|
* is safe.
|
|
*/
|
|
val = sss_rate / (EXYNOS_TRNG_CLOCK_RATE * 2);
|
|
if (val > 0x7fff) {
|
|
dev_err(trng->dev, "clock divider too large: %d", val);
|
|
return -ERANGE;
|
|
}
|
|
val = val << 1;
|
|
writel_relaxed(val, trng->mem + EXYNOS_TRNG_CLKDIV);
|
|
|
|
/* Enable the generator. */
|
|
val = EXYNOS_TRNG_CTRL_RNGEN;
|
|
writel_relaxed(val, trng->mem + EXYNOS_TRNG_CTRL);
|
|
|
|
/*
|
|
* Disable post-processing. /dev/hwrng is supposed to deliver
|
|
* unprocessed data.
|
|
*/
|
|
writel_relaxed(0, trng->mem + EXYNOS_TRNG_POST_CTRL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int exynos_trng_probe(struct platform_device *pdev)
|
|
{
|
|
struct exynos_trng_dev *trng;
|
|
struct resource *res;
|
|
int ret = -ENOMEM;
|
|
|
|
trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
|
|
if (!trng)
|
|
return ret;
|
|
|
|
trng->rng.name = devm_kstrdup(&pdev->dev, dev_name(&pdev->dev),
|
|
GFP_KERNEL);
|
|
if (!trng->rng.name)
|
|
return ret;
|
|
|
|
trng->rng.init = exynos_trng_init;
|
|
trng->rng.read = exynos_trng_do_read;
|
|
trng->rng.priv = (unsigned long) trng;
|
|
|
|
platform_set_drvdata(pdev, trng);
|
|
trng->dev = &pdev->dev;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
trng->mem = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(trng->mem))
|
|
return PTR_ERR(trng->mem);
|
|
|
|
pm_runtime_enable(&pdev->dev);
|
|
ret = pm_runtime_get_sync(&pdev->dev);
|
|
if (ret < 0) {
|
|
dev_err(&pdev->dev, "Could not get runtime PM.\n");
|
|
goto err_pm_get;
|
|
}
|
|
|
|
trng->clk = devm_clk_get(&pdev->dev, "secss");
|
|
if (IS_ERR(trng->clk)) {
|
|
ret = PTR_ERR(trng->clk);
|
|
dev_err(&pdev->dev, "Could not get clock.\n");
|
|
goto err_clock;
|
|
}
|
|
|
|
ret = clk_prepare_enable(trng->clk);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "Could not enable the clk.\n");
|
|
goto err_clock;
|
|
}
|
|
|
|
ret = hwrng_register(&trng->rng);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "Could not register hwrng device.\n");
|
|
goto err_register;
|
|
}
|
|
|
|
dev_info(&pdev->dev, "Exynos True Random Number Generator.\n");
|
|
|
|
return 0;
|
|
|
|
err_register:
|
|
clk_disable_unprepare(trng->clk);
|
|
|
|
err_clock:
|
|
pm_runtime_put_sync(&pdev->dev);
|
|
|
|
err_pm_get:
|
|
pm_runtime_disable(&pdev->dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int exynos_trng_remove(struct platform_device *pdev)
|
|
{
|
|
struct exynos_trng_dev *trng = platform_get_drvdata(pdev);
|
|
|
|
hwrng_unregister(&trng->rng);
|
|
clk_disable_unprepare(trng->clk);
|
|
|
|
pm_runtime_put_sync(&pdev->dev);
|
|
pm_runtime_disable(&pdev->dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __maybe_unused exynos_trng_suspend(struct device *dev)
|
|
{
|
|
pm_runtime_put_sync(dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __maybe_unused exynos_trng_resume(struct device *dev)
|
|
{
|
|
int ret;
|
|
|
|
ret = pm_runtime_get_sync(dev);
|
|
if (ret < 0) {
|
|
dev_err(dev, "Could not get runtime PM.\n");
|
|
pm_runtime_put_noidle(dev);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static SIMPLE_DEV_PM_OPS(exynos_trng_pm_ops, exynos_trng_suspend,
|
|
exynos_trng_resume);
|
|
|
|
static const struct of_device_id exynos_trng_dt_match[] = {
|
|
{
|
|
.compatible = "samsung,exynos5250-trng",
|
|
},
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(of, exynos_trng_dt_match);
|
|
|
|
static struct platform_driver exynos_trng_driver = {
|
|
.driver = {
|
|
.name = "exynos-trng",
|
|
.pm = &exynos_trng_pm_ops,
|
|
.of_match_table = exynos_trng_dt_match,
|
|
},
|
|
.probe = exynos_trng_probe,
|
|
.remove = exynos_trng_remove,
|
|
};
|
|
|
|
module_platform_driver(exynos_trng_driver);
|
|
MODULE_AUTHOR("Łukasz Stelmach");
|
|
MODULE_DESCRIPTION("H/W TRNG driver for Exynos chips");
|
|
MODULE_LICENSE("GPL v2");
|