155 lines
3.4 KiB
C
155 lines
3.4 KiB
C
/*
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* Broadcom BCM63xx Random Number Generator support
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*
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* Copyright (C) 2011, Florian Fainelli <florian@openwrt.org>
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* Copyright (C) 2009, Broadcom Corporation
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*
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include <linux/err.h>
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#include <linux/clk.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/of.h>
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#define RNG_CTRL 0x00
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#define RNG_EN (1 << 0)
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#define RNG_STAT 0x04
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#define RNG_AVAIL_MASK (0xff000000)
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#define RNG_DATA 0x08
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#define RNG_THRES 0x0c
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#define RNG_MASK 0x10
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struct bcm63xx_rng_priv {
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struct hwrng rng;
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struct clk *clk;
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void __iomem *regs;
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};
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#define to_rng_priv(rng) container_of(rng, struct bcm63xx_rng_priv, rng)
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static int bcm63xx_rng_init(struct hwrng *rng)
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{
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struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
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u32 val;
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int error;
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error = clk_prepare_enable(priv->clk);
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if (error)
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return error;
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val = __raw_readl(priv->regs + RNG_CTRL);
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val |= RNG_EN;
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__raw_writel(val, priv->regs + RNG_CTRL);
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return 0;
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}
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static void bcm63xx_rng_cleanup(struct hwrng *rng)
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{
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struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
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u32 val;
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val = __raw_readl(priv->regs + RNG_CTRL);
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val &= ~RNG_EN;
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__raw_writel(val, priv->regs + RNG_CTRL);
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clk_disable_unprepare(priv->clk);
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}
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static int bcm63xx_rng_data_present(struct hwrng *rng, int wait)
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{
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struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
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return __raw_readl(priv->regs + RNG_STAT) & RNG_AVAIL_MASK;
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}
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static int bcm63xx_rng_data_read(struct hwrng *rng, u32 *data)
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{
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struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
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*data = __raw_readl(priv->regs + RNG_DATA);
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return 4;
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}
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static int bcm63xx_rng_probe(struct platform_device *pdev)
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{
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struct resource *r;
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int ret;
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struct bcm63xx_rng_priv *priv;
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r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!r) {
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dev_err(&pdev->dev, "no iomem resource\n");
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return -ENXIO;
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}
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->rng.name = pdev->name;
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priv->rng.init = bcm63xx_rng_init;
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priv->rng.cleanup = bcm63xx_rng_cleanup;
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priv->rng.data_present = bcm63xx_rng_data_present;
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priv->rng.data_read = bcm63xx_rng_data_read;
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priv->clk = devm_clk_get(&pdev->dev, "ipsec");
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if (IS_ERR(priv->clk)) {
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ret = PTR_ERR(priv->clk);
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dev_err(&pdev->dev, "no clock for device: %d\n", ret);
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return ret;
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}
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if (!devm_request_mem_region(&pdev->dev, r->start,
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resource_size(r), pdev->name)) {
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dev_err(&pdev->dev, "request mem failed");
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return -EBUSY;
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}
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priv->regs = devm_ioremap_nocache(&pdev->dev, r->start,
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resource_size(r));
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if (!priv->regs) {
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dev_err(&pdev->dev, "ioremap failed");
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return -ENOMEM;
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}
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ret = devm_hwrng_register(&pdev->dev, &priv->rng);
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if (ret) {
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dev_err(&pdev->dev, "failed to register rng device: %d\n",
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ret);
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return ret;
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}
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dev_info(&pdev->dev, "registered RNG driver\n");
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return 0;
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}
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#ifdef CONFIG_OF
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static const struct of_device_id bcm63xx_rng_of_match[] = {
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{ .compatible = "brcm,bcm6368-rng", },
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{},
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};
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MODULE_DEVICE_TABLE(of, bcm63xx_rng_of_match);
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#endif
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static struct platform_driver bcm63xx_rng_driver = {
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.probe = bcm63xx_rng_probe,
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.driver = {
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.name = "bcm63xx-rng",
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.of_match_table = of_match_ptr(bcm63xx_rng_of_match),
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},
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};
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module_platform_driver(bcm63xx_rng_driver);
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MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
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MODULE_DESCRIPTION("Broadcom BCM63xx RNG driver");
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MODULE_LICENSE("GPL");
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