122 lines
2.5 KiB
C
122 lines
2.5 KiB
C
/*
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* RNG driver for Moschip MCS814x SoC
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*
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* Copyright 2012 (C), Florian Fainelli <florian@openwrt.org>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/platform_device.h>
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#include <linux/hw_random.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#define STAT 0x00
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#define RND 0x04
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struct mcs814x_rng_priv {
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void __iomem *regs;
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};
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static int mcs814x_rng_data_read(struct hwrng *rng, u32 *buffer)
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{
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struct mcs814x_rng_priv *priv = (struct mcs814x_rng_priv *)rng->priv;
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*buffer = readl_relaxed(priv->regs + RND);
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return 4;
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}
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static int mcs814x_rng_probe(struct platform_device *pdev)
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{
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struct resource *res;
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struct mcs814x_rng_priv *priv;
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struct hwrng *rng;
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int ret;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -ENODEV;
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priv = kzalloc(sizeof(*priv), GFP_KERNEL);
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if (!priv) {
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ret = -ENOMEM;
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goto out;
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}
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rng = kzalloc(sizeof(*rng), GFP_KERNEL);
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if (!rng) {
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ret = -ENOMEM;
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goto out_priv;
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}
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platform_set_drvdata(pdev, rng);
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rng->priv = (unsigned long)priv;
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rng->name = pdev->name;
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rng->data_read = mcs814x_rng_data_read;
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priv->regs = devm_ioremap_resource(&pdev->dev, res);
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if (!priv->regs) {
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ret = -ENOMEM;
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goto out_rng;
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}
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ret = hwrng_register(rng);
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if (ret) {
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dev_err(&pdev->dev, "failed to register hwrng driver\n");
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goto out;
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}
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dev_info(&pdev->dev, "registered\n");
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return ret;
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out_rng:
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platform_set_drvdata(pdev, NULL);
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kfree(rng);
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out_priv:
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kfree(priv);
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out:
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return ret;
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}
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static int mcs814x_rng_remove(struct platform_device *pdev)
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{
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struct hwrng *rng = platform_get_drvdata(pdev);
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struct mcs814x_rng_priv *priv = (struct mcs814x_rng_priv *)rng->priv;
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hwrng_unregister(rng);
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kfree(priv);
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kfree(rng);
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platform_set_drvdata(pdev, NULL);
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return 0;
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}
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static const struct of_device_id mcs814x_rng_ids[] = {
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{ .compatible = "moschip,mcs814x-rng", },
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{ /* sentinel */ },
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};
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static struct platform_driver mcs814x_rng_driver = {
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.driver = {
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.name = "mcs814x-rng",
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.owner = THIS_MODULE,
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.of_match_table = mcs814x_rng_ids,
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},
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.probe = mcs814x_rng_probe,
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.remove = mcs814x_rng_remove,
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};
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module_platform_driver(mcs814x_rng_driver);
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MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
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MODULE_DESCRIPTION("H/W Random Number Generator (RNG) for Moschip MCS814x");
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MODULE_LICENSE("GPL");
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