// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
/*
- * Device driver for True RNG in HiSTB SoCs
- *
* Copyright (c) 2023 David Yang
*/
-#include <crypto/internal/rng.h>
-#include <linux/device.h>
#include <linux/err.h>
#include <linux/hw_random.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/of_device.h>
+#include <linux/platform_device.h>
-#define HISTB_TRNG_CTRL 0x0
+#define RNG_CTRL 0x0
#define RNG_SOURCE GENMASK(1, 0)
#define DROP_ENABLE BIT(5)
#define POST_PROCESS_ENABLE BIT(7)
#define POST_PROCESS_DEPTH GENMASK(15, 8)
-#define HISTB_TRNG_NUMBER 0x4
-#define HISTB_TRNG_STAT 0x8
+#define RNG_NUMBER 0x4
+#define RNG_STAT 0x8
#define DATA_COUNT GENMASK(2, 0) /* max 4 */
-struct histb_trng_priv {
+struct histb_rng_priv {
struct hwrng rng;
void __iomem *base;
};
* depth = 1 -> ~1ms
* depth = 255 -> ~16ms
*/
-static int histb_trng_wait(void __iomem *base)
+static int histb_rng_wait(void __iomem *base)
{
u32 val;
- return readl_relaxed_poll_timeout(base + HISTB_TRNG_STAT, val,
+ return readl_relaxed_poll_timeout(base + RNG_STAT, val,
val & DATA_COUNT, 1000, 30 * 1000);
}
-static void histb_trng_init(void __iomem *base, unsigned int depth)
+static void histb_rng_init(void __iomem *base, unsigned int depth)
{
u32 val;
- val = readl_relaxed(base + HISTB_TRNG_CTRL);
+ val = readl_relaxed(base + RNG_CTRL);
val &= ~RNG_SOURCE;
val |= 2;
val |= POST_PROCESS_ENABLE;
val |= DROP_ENABLE;
- writel_relaxed(val, base + HISTB_TRNG_CTRL);
+ writel_relaxed(val, base + RNG_CTRL);
}
-static int histb_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
+static int histb_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
- struct histb_trng_priv *priv = container_of(rng, typeof(*priv), rng);
+ struct histb_rng_priv *priv = container_of(rng, typeof(*priv), rng);
void __iomem *base = priv->base;
for (int i = 0; i < max; i += sizeof(u32)) {
- if (!(readl_relaxed(base + HISTB_TRNG_STAT) & DATA_COUNT)) {
+ if (!(readl_relaxed(base + RNG_STAT) & DATA_COUNT)) {
if (!wait)
return i;
- if (histb_trng_wait(base)) {
+ if (histb_rng_wait(base)) {
pr_err("failed to generate random number, generated %d\n",
i);
return i ? i : -ETIMEDOUT;
}
}
- *(u32 *) (data + i) = readl_relaxed(base + HISTB_TRNG_NUMBER);
+ *(u32 *) (data + i) = readl_relaxed(base + RNG_NUMBER);
}
return max;
}
-static unsigned int histb_trng_get_depth(void __iomem *base)
+static unsigned int histb_rng_get_depth(void __iomem *base)
{
- return (readl_relaxed(base + HISTB_TRNG_CTRL) & POST_PROCESS_DEPTH) >> 8;
+ return (readl_relaxed(base + RNG_CTRL) & POST_PROCESS_DEPTH) >> 8;
}
static ssize_t
depth_show(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct histb_trng_priv *priv = dev_get_drvdata(dev);
+ struct histb_rng_priv *priv = dev_get_drvdata(dev);
void __iomem *base = priv->base;
- return sprintf(buf, "%d\n", histb_trng_get_depth(base));
+ return sprintf(buf, "%d\n", histb_rng_get_depth(base));
}
static ssize_t
depth_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
- struct histb_trng_priv *priv = dev_get_drvdata(dev);
+ struct histb_rng_priv *priv = dev_get_drvdata(dev);
void __iomem *base = priv->base;
unsigned int depth;
if (kstrtouint(buf, 0, &depth))
return -ERANGE;
- histb_trng_init(base, depth);
+ histb_rng_init(base, depth);
return count;
}
static DEVICE_ATTR_RW(depth);
-static struct attribute *histb_trng_attrs[] = {
+static struct attribute *histb_rng_attrs[] = {
&dev_attr_depth.attr,
NULL,
};
-ATTRIBUTE_GROUPS(histb_trng);
+ATTRIBUTE_GROUPS(histb_rng);
-static int histb_trng_probe(struct platform_device *pdev)
+static int histb_rng_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
- struct histb_trng_priv *priv;
+ struct histb_rng_priv *priv;
void __iomem *base;
int ret;
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
- return -ENOMEM;
+ return PTR_ERR(base);
- histb_trng_init(base, 144);
- if (histb_trng_wait(base)) {
+ histb_rng_init(base, 144);
+ if (histb_rng_wait(base)) {
dev_err(dev, "cannot bring up device\n");
return -ENODEV;
}
priv->base = base;
priv->rng.name = pdev->name;
- priv->rng.read = histb_trng_read;
+ priv->rng.read = histb_rng_read;
ret = devm_hwrng_register(dev, &priv->rng);
if (ret) {
dev_err(dev, "failed to register hwrng: %d\n", ret);
return 0;
}
-static const struct of_device_id histb_trng_of_match[] = {
- { .compatible = "hisilicon,histb-trng", },
+static const struct of_device_id histb_rng_of_match[] = {
+ { .compatible = "hisilicon,histb-rng", },
{ }
};
+MODULE_DEVICE_TABLE(of, histb_rng_of_match);
-static struct platform_driver histb_trng_driver = {
- .probe = histb_trng_probe,
+static struct platform_driver histb_rng_driver = {
+ .probe = histb_rng_probe,
.driver = {
- .name = "histb-trng",
- .of_match_table = histb_trng_of_match,
- .dev_groups = histb_trng_groups,
+ .name = "histb-rng",
+ .of_match_table = histb_rng_of_match,
+ .dev_groups = histb_rng_groups,
},
};
-module_platform_driver(histb_trng_driver);
+module_platform_driver(histb_rng_driver);
-MODULE_DESCRIPTION("HiSTB True RNG");
+MODULE_DESCRIPTION("Hisilicon STB random number generator driver");
MODULE_LICENSE("Dual MIT/GPL");
MODULE_AUTHOR("David Yang <mmyangfl@gmail.com>");
projects / platform / kernel / linux-starfive.git / commitdiff