summaryrefslogtreecommitdiff
path: root/drivers/char/hw_random/bcm63xx-rng.c
blob: ae95bcb18d4a8390d9c0cdd99047ddabb982c097 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
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 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");