[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>
#include <linux/of.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>
47cd3060	15	#include <linux/of.h>
553072b2	16
b515e0f9 FF	17	#define RNG_CTRL 0x00
	18	#define RNG_EN (1 << 0)
	19
	20	#define RNG_STAT 0x04
	21	#define RNG_AVAIL_MASK (0xff000000)
	22
	23	#define RNG_DATA 0x08
	24	#define RNG_THRES 0x0c
	25	#define RNG_MASK 0x10
553072b2 FF	26
553072b2 FF	27	struct bcm63xx_rng_priv {
6229c160	28	struct hwrng rng;
553072b2 FF	29	struct clk *clk;
	30	void __iomem *regs;
	31	};
	32
6229c160	33	#define to_rng_priv(rng) container_of(rng, struct bcm63xx_rng_priv, rng)
553072b2 FF	34
	35	static int bcm63xx_rng_init(struct hwrng *rng)
	36	{
	37	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
	38	u32 val;
6229c160 DT	39	int error;
	40
	41	error = clk_prepare_enable(priv->clk);
	42	if (error)
	43	return error;
553072b2	44
f7591fae	45	val = __raw_readl(priv->regs + RNG_CTRL);
553072b2	46	val \|= RNG_EN;
f7591fae	47	__raw_writel(val, priv->regs + RNG_CTRL);
553072b2 FF	48
	49	return 0;
	50	}
	51
	52	static void bcm63xx_rng_cleanup(struct hwrng *rng)
	53	{
	54	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
	55	u32 val;
	56
f7591fae	57	val = __raw_readl(priv->regs + RNG_CTRL);
553072b2	58	val &= ~RNG_EN;
f7591fae	59	__raw_writel(val, priv->regs + RNG_CTRL);
6229c160	60
f440c4ee	61	clk_disable_unprepare(priv->clk);
553072b2 FF	62	}
	63
	64	static int bcm63xx_rng_data_present(struct hwrng *rng, int wait)
	65	{
	66	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
	67
f7591fae	68	return __raw_readl(priv->regs + RNG_STAT) & RNG_AVAIL_MASK;
553072b2 FF	69	}
	70
	71	static int bcm63xx_rng_data_read(struct hwrng rng, u32 data)
	72	{
	73	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
	74
f7591fae	75	*data = __raw_readl(priv->regs + RNG_DATA);
553072b2 FF	76
	77	return 4;
	78	}
	79
bcd2982a	80	static int bcm63xx_rng_probe(struct platform_device *pdev)
553072b2 FF	81	{
553072b2 FF	82	struct resource *r;
553072b2 FF	83	int ret;
553072b2 FF	84	struct bcm63xx_rng_priv *priv;
553072b2 FF	85
	86	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	87	if (!r) {
	88	dev_err(&pdev->dev, "no iomem resource\n");
6229c160	89	return -ENXIO;
553072b2 FF	90	}
553072b2 FF	91
0052a654	92	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
6229c160 DT	93	if (!priv)
	94	return -ENOMEM;
	95
	96	priv->rng.name = pdev->name;
	97	priv->rng.init = bcm63xx_rng_init;
	98	priv->rng.cleanup = bcm63xx_rng_cleanup;
f440c4ee	99	priv->rng.data_present = bcm63xx_rng_data_present;
6229c160 DT	100	priv->rng.data_read = bcm63xx_rng_data_read;
	101
	102	priv->clk = devm_clk_get(&pdev->dev, "ipsec");
	103	if (IS_ERR(priv->clk)) {
f440c4ee ÁFR	104	ret = PTR_ERR(priv->clk);
	105	dev_err(&pdev->dev, "no clock for device: %d\n", ret);
	106	return ret;
553072b2 FF	107	}
553072b2 FF	108
553072b2 FF	109	if (!devm_request_mem_region(&pdev->dev, r->start,
	110	resource_size(r), pdev->name)) {
	111	dev_err(&pdev->dev, "request mem failed");
6229c160	112	return -EBUSY;
553072b2 FF	113	}
	114
	115	priv->regs = devm_ioremap_nocache(&pdev->dev, r->start,
	116	resource_size(r));
	117	if (!priv->regs) {
	118	dev_err(&pdev->dev, "ioremap failed");
6229c160	119	return -ENOMEM;
553072b2 FF	120	}
553072b2 FF	121
f440c4ee ÁFR	122	ret = devm_hwrng_register(&pdev->dev, &priv->rng);
f440c4ee ÁFR	123	if (ret) {
6229c160	124	dev_err(&pdev->dev, "failed to register rng device: %d\n",
f440c4ee ÁFR	125	ret);
f440c4ee ÁFR	126	return ret;
553072b2 FF	127	}
	128
	129	dev_info(&pdev->dev, "registered RNG driver\n");
	130
553072b2 FF	131	return 0;
	132	}
	133
1879f40a	134	#ifdef CONFIG_OF
7b651706 ÁFR	135	static const struct of_device_id bcm63xx_rng_of_match[] = {
	136	{ .compatible = "brcm,bcm6368-rng", },
	137	{},
	138	};
	139	MODULE_DEVICE_TABLE(of, bcm63xx_rng_of_match);
1879f40a	140	#endif
7b651706	141
553072b2 FF	142	static struct platform_driver bcm63xx_rng_driver = {
553072b2 FF	143	.probe = bcm63xx_rng_probe,
553072b2 FF	144	.driver = {
553072b2 FF	145	.name = "bcm63xx-rng",
1879f40a	146	.of_match_table = of_match_ptr(bcm63xx_rng_of_match),
553072b2 FF	147	},
	148	};
	149
	150	module_platform_driver(bcm63xx_rng_driver);
	151
	152	MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
	153	MODULE_DESCRIPTION("Broadcom BCM63xx RNG driver");
	154	MODULE_LICENSE("GPL");