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