kernel/drivers/char/hw_random/ixp4xx-rng.c
2024-07-22 17:22:30 +08:00

79 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* drivers/char/hw_random/ixp4xx-rng.c
*
* RNG driver for Intel IXP4xx family of NPUs
*
* Author: Deepak Saxena <dsaxena@plexity.net>
*
* Copyright 2005 (c) MontaVista Software, Inc.
*
* Fixes by Michael Buesch
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/hw_random.h>
#include <linux/of.h>
#include <linux/soc/ixp4xx/cpu.h>
#include <asm/io.h>
static int ixp4xx_rng_data_read(struct hwrng *rng, u32 *buffer)
{
void __iomem * rng_base = (void __iomem *)rng->priv;
*buffer = __raw_readl(rng_base);
return 4;
}
static struct hwrng ixp4xx_rng_ops = {
.name = "ixp4xx",
.data_read = ixp4xx_rng_data_read,
};
static int ixp4xx_rng_probe(struct platform_device *pdev)
{
void __iomem * rng_base;
struct device *dev = &pdev->dev;
struct resource *res;
if (!cpu_is_ixp46x()) /* includes IXP455 */
return -ENOSYS;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
rng_base = devm_ioremap_resource(dev, res);
if (IS_ERR(rng_base))
return PTR_ERR(rng_base);
ixp4xx_rng_ops.priv = (unsigned long)rng_base;
return devm_hwrng_register(dev, &ixp4xx_rng_ops);
}
static const struct of_device_id ixp4xx_rng_of_match[] = {
{
.compatible = "intel,ixp46x-rng",
},
{},
};
MODULE_DEVICE_TABLE(of, ixp4xx_rng_of_match);
static struct platform_driver ixp4xx_rng_driver = {
.driver = {
.name = "ixp4xx-hwrandom",
.of_match_table = ixp4xx_rng_of_match,
},
.probe = ixp4xx_rng_probe,
};
module_platform_driver(ixp4xx_rng_driver);
MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
MODULE_DESCRIPTION("H/W Pseudo-Random Number Generator (RNG) driver for IXP45x/46x");
MODULE_LICENSE("GPL");