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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 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 = __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);
}
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");
ret = -ENXIO;
goto out;
}
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv) {
ret = -ENOMEM;
goto out;
}
rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
if (!rng) {
ret = -ENOMEM;
goto out;
}
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;
}
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;
}
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;
}
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:
return ret;
}
static int 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);
return 0;
}
static struct platform_driver bcm63xx_rng_driver = {
.probe = bcm63xx_rng_probe,
.remove = bcm63xx_rng_remove,
.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");
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