[deliverable/linux.git] / drivers / char / hw_random / bcm63xx-rng.c

/*
 * 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");
Commit	Line	Data
553072b2 FF	1	/*
	2	* Broadcom BCM63xx Random Number Generator support
	3	*
	4	* Copyright (C) 2011, Florian Fainelli <florian@openwrt.org>
	5	* Copyright (C) 2009, Broadcom Corporation
	6	*
	7	*/
	8	#include <linux/module.h>
	9	#include <linux/slab.h>
	10	#include <linux/io.h>
	11	#include <linux/err.h>
	12	#include <linux/clk.h>
	13	#include <linux/platform_device.h>
	14	#include <linux/hw_random.h>
	15
b515e0f9 FF	16	#define RNG_CTRL 0x00
	17	#define RNG_EN (1 << 0)
	18
	19	#define RNG_STAT 0x04
	20	#define RNG_AVAIL_MASK (0xff000000)
	21
	22	#define RNG_DATA 0x08
	23	#define RNG_THRES 0x0c
	24	#define RNG_MASK 0x10
553072b2 FF	25
553072b2 FF	26	struct bcm63xx_rng_priv {
6229c160	27	struct hwrng rng;
553072b2 FF	28	struct clk *clk;
	29	void __iomem *regs;
	30	};
	31
6229c160	32	#define to_rng_priv(rng) container_of(rng, struct bcm63xx_rng_priv, rng)
553072b2 FF	33
	34	static int bcm63xx_rng_init(struct hwrng *rng)
	35	{
	36	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
	37	u32 val;
6229c160 DT	38	int error;
	39
	40	error = clk_prepare_enable(priv->clk);
	41	if (error)
	42	return error;
553072b2	43
f7591fae	44	val = __raw_readl(priv->regs + RNG_CTRL);
553072b2	45	val \|= RNG_EN;
f7591fae	46	__raw_writel(val, priv->regs + RNG_CTRL);
553072b2 FF	47
	48	return 0;
	49	}
	50
	51	static void bcm63xx_rng_cleanup(struct hwrng *rng)
	52	{
	53	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
	54	u32 val;
	55
f7591fae	56	val = __raw_readl(priv->regs + RNG_CTRL);
553072b2	57	val &= ~RNG_EN;
f7591fae	58	__raw_writel(val, priv->regs + RNG_CTRL);
6229c160	59
f440c4ee	60	clk_disable_unprepare(priv->clk);
553072b2 FF	61	}
	62
	63	static int bcm63xx_rng_data_present(struct hwrng *rng, int wait)
	64	{
	65	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
	66
f7591fae	67	return __raw_readl(priv->regs + RNG_STAT) & RNG_AVAIL_MASK;
553072b2 FF	68	}
	69
	70	static int bcm63xx_rng_data_read(struct hwrng rng, u32 data)
	71	{
	72	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
	73
f7591fae	74	*data = __raw_readl(priv->regs + RNG_DATA);
553072b2 FF	75
	76	return 4;
	77	}
	78
bcd2982a	79	static int bcm63xx_rng_probe(struct platform_device *pdev)
553072b2 FF	80	{
553072b2 FF	81	struct resource *r;
553072b2 FF	82	int ret;
553072b2 FF	83	struct bcm63xx_rng_priv *priv;
553072b2 FF	84
	85	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	86	if (!r) {
	87	dev_err(&pdev->dev, "no iomem resource\n");
6229c160	88	return -ENXIO;
553072b2 FF	89	}
553072b2 FF	90
0052a654	91	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
6229c160 DT	92	if (!priv)
	93	return -ENOMEM;
	94
	95	priv->rng.name = pdev->name;
	96	priv->rng.init = bcm63xx_rng_init;
	97	priv->rng.cleanup = bcm63xx_rng_cleanup;
f440c4ee	98	priv->rng.data_present = bcm63xx_rng_data_present;
6229c160 DT	99	priv->rng.data_read = bcm63xx_rng_data_read;
	100
	101	priv->clk = devm_clk_get(&pdev->dev, "ipsec");
	102	if (IS_ERR(priv->clk)) {
f440c4ee ÁFR	103	ret = PTR_ERR(priv->clk);
	104	dev_err(&pdev->dev, "no clock for device: %d\n", ret);
	105	return ret;
553072b2 FF	106	}
553072b2 FF	107
553072b2 FF	108	if (!devm_request_mem_region(&pdev->dev, r->start,
	109	resource_size(r), pdev->name)) {
	110	dev_err(&pdev->dev, "request mem failed");
6229c160	111	return -EBUSY;
553072b2 FF	112	}
	113
	114	priv->regs = devm_ioremap_nocache(&pdev->dev, r->start,
	115	resource_size(r));
	116	if (!priv->regs) {
	117	dev_err(&pdev->dev, "ioremap failed");
6229c160	118	return -ENOMEM;
553072b2 FF	119	}
553072b2 FF	120
f440c4ee ÁFR	121	ret = devm_hwrng_register(&pdev->dev, &priv->rng);
f440c4ee ÁFR	122	if (ret) {
6229c160	123	dev_err(&pdev->dev, "failed to register rng device: %d\n",
f440c4ee ÁFR	124	ret);
f440c4ee ÁFR	125	return ret;
553072b2 FF	126	}
	127
	128	dev_info(&pdev->dev, "registered RNG driver\n");
	129
553072b2 FF	130	return 0;
	131	}
	132
1879f40a	133	#ifdef CONFIG_OF
7b651706 ÁFR	134	static const struct of_device_id bcm63xx_rng_of_match[] = {
	135	{ .compatible = "brcm,bcm6368-rng", },
	136	{},
	137	};
	138	MODULE_DEVICE_TABLE(of, bcm63xx_rng_of_match);
1879f40a	139	#endif
7b651706	140
553072b2 FF	141	static struct platform_driver bcm63xx_rng_driver = {
553072b2 FF	142	.probe = bcm63xx_rng_probe,
553072b2 FF	143	.driver = {
553072b2 FF	144	.name = "bcm63xx-rng",
1879f40a	145	.of_match_table = of_match_ptr(bcm63xx_rng_of_match),
553072b2 FF	146	},
	147	};
	148
	149	module_platform_driver(bcm63xx_rng_driver);
	150
	151	MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
	152	MODULE_DESCRIPTION("Broadcom BCM63xx RNG driver");
	153	MODULE_LICENSE("GPL");