tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
16#include <bcm63xx_io.h>
17#include <bcm63xx_regs.h>
18
19struct bcm63xx_rng_priv {
20 struct clk *clk;
21 void __iomem *regs;
22};
23
24#define to_rng_priv(rng) ((struct bcm63xx_rng_priv *)rng->priv)
25
26static int bcm63xx_rng_init(struct hwrng *rng)
27{
28 struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
29 u32 val;
30
31 val = bcm_readl(priv->regs + RNG_CTRL);
32 val |= RNG_EN;
33 bcm_writel(val, priv->regs + RNG_CTRL);
34
35 return 0;
36}
37
38static void bcm63xx_rng_cleanup(struct hwrng *rng)
39{
40 struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
41 u32 val;
42
43 val = bcm_readl(priv->regs + RNG_CTRL);
44 val &= ~RNG_EN;
45 bcm_writel(val, priv->regs + RNG_CTRL);
46}
47
48static int bcm63xx_rng_data_present(struct hwrng *rng, int wait)
49{
50 struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
51
52 return bcm_readl(priv->regs + RNG_STAT) & RNG_AVAIL_MASK;
53}
54
55static int bcm63xx_rng_data_read(struct hwrng *rng, u32 *data)
56{
57 struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
58
59 *data = bcm_readl(priv->regs + RNG_DATA);
60
61 return 4;
62}
63
64static int bcm63xx_rng_probe(struct platform_device *pdev)
65{
66 struct resource *r;
67 struct clk *clk;
68 int ret;
69 struct bcm63xx_rng_priv *priv;
70 struct hwrng *rng;
71
72 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
73 if (!r) {
74 dev_err(&pdev->dev, "no iomem resource\n");
75 ret = -ENXIO;
76 goto out;
77 }
78
79 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
80 if (!priv) {
81 dev_err(&pdev->dev, "no memory for private structure\n");
82 ret = -ENOMEM;
83 goto out;
84 }
85
86 rng = kzalloc(sizeof(*rng), GFP_KERNEL);
87 if (!rng) {
88 dev_err(&pdev->dev, "no memory for rng structure\n");
89 ret = -ENOMEM;
90 goto out_free_priv;
91 }
92
93 platform_set_drvdata(pdev, rng);
94 rng->priv = (unsigned long)priv;
95 rng->name = pdev->name;
96 rng->init = bcm63xx_rng_init;
97 rng->cleanup = bcm63xx_rng_cleanup;
98 rng->data_present = bcm63xx_rng_data_present;
99 rng->data_read = bcm63xx_rng_data_read;
100
101 clk = clk_get(&pdev->dev, "ipsec");
102 if (IS_ERR(clk)) {
103 dev_err(&pdev->dev, "no clock for device\n");
104 ret = PTR_ERR(clk);
105 goto out_free_rng;
106 }
107
108 priv->clk = clk;
109
110 if (!devm_request_mem_region(&pdev->dev, r->start,
111 resource_size(r), pdev->name)) {
112 dev_err(&pdev->dev, "request mem failed");
113 ret = -ENOMEM;
114 goto out_free_rng;
115 }
116
117 priv->regs = devm_ioremap_nocache(&pdev->dev, r->start,
118 resource_size(r));
119 if (!priv->regs) {
120 dev_err(&pdev->dev, "ioremap failed");
121 ret = -ENOMEM;
122 goto out_free_rng;
123 }
124
125 clk_enable(clk);
126
127 ret = hwrng_register(rng);
128 if (ret) {
129 dev_err(&pdev->dev, "failed to register rng device\n");
130 goto out_clk_disable;
131 }
132
133 dev_info(&pdev->dev, "registered RNG driver\n");
134
135 return 0;
136
137out_clk_disable:
138 clk_disable(clk);
139out_free_rng:
140 kfree(rng);
141out_free_priv:
142 kfree(priv);
143out:
144 return ret;
145}
146
147static int bcm63xx_rng_remove(struct platform_device *pdev)
148{
149 struct hwrng *rng = platform_get_drvdata(pdev);
150 struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
151
152 hwrng_unregister(rng);
153 clk_disable(priv->clk);
154 kfree(priv);
155 kfree(rng);
156
157 return 0;
158}
159
160static struct platform_driver bcm63xx_rng_driver = {
161 .probe = bcm63xx_rng_probe,
162 .remove = bcm63xx_rng_remove,
163 .driver = {
164 .name = "bcm63xx-rng",
165 .owner = THIS_MODULE,
166 },
167};
168
169module_platform_driver(bcm63xx_rng_driver);
170
171MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
172MODULE_DESCRIPTION("Broadcom BCM63xx RNG driver");
173MODULE_LICENSE("GPL");