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1// SPDX-License-Identifier: GPL-2.02/*3 * drivers/char/hw_random/ixp4xx-rng.c4 *5 * RNG driver for Intel IXP4xx family of NPUs6 *7 * Author: Deepak Saxena <dsaxena@plexity.net>8 *9 * Copyright 2005 (c) MontaVista Software, Inc.10 *11 * Fixes by Michael Buesch12 */13 14#include <linux/kernel.h>15#include <linux/types.h>16#include <linux/module.h>17#include <linux/moduleparam.h>18#include <linux/platform_device.h>19#include <linux/init.h>20#include <linux/bitops.h>21#include <linux/hw_random.h>22#include <linux/of.h>23#include <linux/soc/ixp4xx/cpu.h>24 25#include <asm/io.h>26 27static int ixp4xx_rng_data_read(struct hwrng *rng, u32 *buffer)28{29 void __iomem * rng_base = (void __iomem *)rng->priv;30 31 *buffer = __raw_readl(rng_base);32 33 return 4;34}35 36static struct hwrng ixp4xx_rng_ops = {37 .name = "ixp4xx",38 .data_read = ixp4xx_rng_data_read,39};40 41static int ixp4xx_rng_probe(struct platform_device *pdev)42{43 void __iomem * rng_base;44 struct device *dev = &pdev->dev;45 46 if (!cpu_is_ixp46x()) /* includes IXP455 */47 return -ENOSYS;48 49 rng_base = devm_platform_ioremap_resource(pdev, 0);50 if (IS_ERR(rng_base))51 return PTR_ERR(rng_base);52 53 ixp4xx_rng_ops.priv = (unsigned long)rng_base;54 return devm_hwrng_register(dev, &ixp4xx_rng_ops);55}56 57static const struct of_device_id ixp4xx_rng_of_match[] = {58 {59 .compatible = "intel,ixp46x-rng",60 },61 {},62};63MODULE_DEVICE_TABLE(of, ixp4xx_rng_of_match);64 65static struct platform_driver ixp4xx_rng_driver = {66 .driver = {67 .name = "ixp4xx-hwrandom",68 .of_match_table = ixp4xx_rng_of_match,69 },70 .probe = ixp4xx_rng_probe,71};72module_platform_driver(ixp4xx_rng_driver);73 74MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");75MODULE_DESCRIPTION("H/W Pseudo-Random Number Generator (RNG) driver for IXP45x/46x");76MODULE_LICENSE("GPL");77