2 * Broadcom BCM63xx Random Number Generator support
4 * Copyright (C) 2011, Florian Fainelli <florian@openwrt.org>
5 * Copyright (C) 2009, Broadcom Corporation
8 #include <linux/module.h>
9 #include <linux/slab.h>
11 #include <linux/err.h>
12 #include <linux/clk.h>
13 #include <linux/platform_device.h>
14 #include <linux/hw_random.h>
17 #define RNG_EN (1 << 0)
20 #define RNG_AVAIL_MASK (0xff000000)
23 #define RNG_THRES 0x0c
26 struct bcm63xx_rng_priv {
32 #define to_rng_priv(rng) container_of(rng, struct bcm63xx_rng_priv, rng)
34 static int bcm63xx_rng_init(struct hwrng *rng)
36 struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
40 error = clk_prepare_enable(priv->clk);
44 val = __raw_readl(priv->regs + RNG_CTRL);
46 __raw_writel(val, priv->regs + RNG_CTRL);
51 static void bcm63xx_rng_cleanup(struct hwrng *rng)
53 struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
56 val = __raw_readl(priv->regs + RNG_CTRL);
58 __raw_writel(val, priv->regs + RNG_CTRL);
60 clk_disable_unprepare(priv->clk);
63 static int bcm63xx_rng_data_present(struct hwrng *rng, int wait)
65 struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
67 return __raw_readl(priv->regs + RNG_STAT) & RNG_AVAIL_MASK;
70 static int bcm63xx_rng_data_read(struct hwrng *rng, u32 *data)
72 struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
74 *data = __raw_readl(priv->regs + RNG_DATA);
79 static int bcm63xx_rng_probe(struct platform_device *pdev)
83 struct bcm63xx_rng_priv *priv;
85 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
87 dev_err(&pdev->dev, "no iomem resource\n");
91 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
95 priv->rng.name = pdev->name;
96 priv->rng.init = bcm63xx_rng_init;
97 priv->rng.cleanup = bcm63xx_rng_cleanup;
98 priv->rng.data_present = bcm63xx_rng_data_present;
99 priv->rng.data_read = bcm63xx_rng_data_read;
101 priv->clk = devm_clk_get(&pdev->dev, "ipsec");
102 if (IS_ERR(priv->clk)) {
103 ret = PTR_ERR(priv->clk);
104 dev_err(&pdev->dev, "no clock for device: %d\n", ret);
108 if (!devm_request_mem_region(&pdev->dev, r->start,
109 resource_size(r), pdev->name)) {
110 dev_err(&pdev->dev, "request mem failed");
114 priv->regs = devm_ioremap_nocache(&pdev->dev, r->start,
117 dev_err(&pdev->dev, "ioremap failed");
121 ret = devm_hwrng_register(&pdev->dev, &priv->rng);
123 dev_err(&pdev->dev, "failed to register rng device: %d\n",
128 dev_info(&pdev->dev, "registered RNG driver\n");
134 static const struct of_device_id bcm63xx_rng_of_match[] = {
135 { .compatible = "brcm,bcm6368-rng", },
138 MODULE_DEVICE_TABLE(of, bcm63xx_rng_of_match);
141 static struct platform_driver bcm63xx_rng_driver = {
142 .probe = bcm63xx_rng_probe,
144 .name = "bcm63xx-rng",
145 .of_match_table = of_match_ptr(bcm63xx_rng_of_match),
149 module_platform_driver(bcm63xx_rng_driver);
151 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
152 MODULE_DESCRIPTION("Broadcom BCM63xx RNG driver");
153 MODULE_LICENSE("GPL");