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/*
* 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");
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