diff options
Diffstat (limited to 'drivers/char/hw_random/bcm63xx-rng.c')
| -rw-r--r-- | drivers/char/hw_random/bcm63xx-rng.c | 175 |
1 files changed, 175 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 000000000000..aec6a4277caa --- /dev/null +++ b/drivers/char/hw_random/bcm63xx-rng.c @@ -0,0 +1,175 @@ +/* + * 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> + +#include <bcm63xx_io.h> +#include <bcm63xx_regs.h> + +struct bcm63xx_rng_priv { + struct clk *clk; + void __iomem *regs; +}; + +#define to_rng_priv(rng) ((struct bcm63xx_rng_priv *)rng->priv) + +static int bcm63xx_rng_init(struct hwrng *rng) +{ + struct bcm63xx_rng_priv *priv = to_rng_priv(rng); + u32 val; + + val = bcm_readl(priv->regs + RNG_CTRL); + val |= RNG_EN; + bcm_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 = bcm_readl(priv->regs + RNG_CTRL); + val &= ~RNG_EN; + bcm_writel(val, priv->regs + RNG_CTRL); +} + +static int bcm63xx_rng_data_present(struct hwrng *rng, int wait) +{ + struct bcm63xx_rng_priv *priv = to_rng_priv(rng); + + return bcm_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 = bcm_readl(priv->regs + RNG_DATA); + + return 4; +} + +static int __devinit 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"); + ret = -ENXIO; + goto out; + } + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) { + dev_err(&pdev->dev, "no memory for private structure\n"); + ret = -ENOMEM; + goto out; + } + + rng = kzalloc(sizeof(*rng), GFP_KERNEL); + if (!rng) { + dev_err(&pdev->dev, "no memory for rng structure\n"); + ret = -ENOMEM; + goto out_free_priv; + } + + platform_set_drvdata(pdev, rng); + rng->priv = (unsigned long)priv; + rng->name = pdev->name; + rng->init = bcm63xx_rng_init; + rng->cleanup = bcm63xx_rng_cleanup; + rng->data_present = bcm63xx_rng_data_present; + rng->data_read = bcm63xx_rng_data_read; + + clk = clk_get(&pdev->dev, "ipsec"); + if (IS_ERR(clk)) { + dev_err(&pdev->dev, "no clock for device\n"); + ret = PTR_ERR(clk); + goto out_free_rng; + } + + priv->clk = clk; + + if (!devm_request_mem_region(&pdev->dev, r->start, + resource_size(r), pdev->name)) { + dev_err(&pdev->dev, "request mem failed"); + ret = -ENOMEM; + goto out_free_rng; + } + + priv->regs = devm_ioremap_nocache(&pdev->dev, r->start, + resource_size(r)); + if (!priv->regs) { + dev_err(&pdev->dev, "ioremap failed"); + ret = -ENOMEM; + goto out_free_rng; + } + + clk_enable(clk); + + ret = hwrng_register(rng); + if (ret) { + dev_err(&pdev->dev, "failed to register rng device\n"); + goto out_clk_disable; + } + + dev_info(&pdev->dev, "registered RNG driver\n"); + + return 0; + +out_clk_disable: + clk_disable(clk); +out_free_rng: + platform_set_drvdata(pdev, NULL); + kfree(rng); +out_free_priv: + kfree(priv); +out: + return ret; +} + +static int __devexit bcm63xx_rng_remove(struct platform_device *pdev) +{ + struct hwrng *rng = platform_get_drvdata(pdev); + struct bcm63xx_rng_priv *priv = to_rng_priv(rng); + + hwrng_unregister(rng); + clk_disable(priv->clk); + kfree(priv); + kfree(rng); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_driver bcm63xx_rng_driver = { + .probe = bcm63xx_rng_probe, + .remove = __devexit_p(bcm63xx_rng_remove), + .driver = { + .name = "bcm63xx-rng", + .owner = THIS_MODULE, + }, +}; + +module_platform_driver(bcm63xx_rng_driver); + +MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); +MODULE_DESCRIPTION("Broadcom BCM63xx RNG driver"); +MODULE_LICENSE("GPL"); |