diff options
Diffstat (limited to 'drivers/char/hw_random/bcm63xx-rng.c')
-rw-r--r-- | drivers/char/hw_random/bcm63xx-rng.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/char/hw_random/bcm63xx-rng.c b/drivers/char/hw_random/bcm63xx-rng.c new file mode 100644 index 000000000..4b31f1387 --- /dev/null +++ b/drivers/char/hw_random/bcm63xx-rng.c @@ -0,0 +1,146 @@ +/* + * 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; + struct clk *clk; + int ret; + struct bcm63xx_rng_priv *priv; + struct hwrng *rng; + + 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; +} + +static struct platform_driver bcm63xx_rng_driver = { + .probe = bcm63xx_rng_probe, + .driver = { + .name = "bcm63xx-rng", + }, +}; + +module_platform_driver(bcm63xx_rng_driver); + +MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); +MODULE_DESCRIPTION("Broadcom BCM63xx RNG driver"); +MODULE_LICENSE("GPL"); |