tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Hardware Random Number Generator support for Cavium Networks
3 * Octeon processor family.
4 *
5 * This file is subject to the terms and conditions of the GNU General Public
6 * License. See the file "COPYING" in the main directory of this archive
7 * for more details.
8 *
9 * Copyright (C) 2009 Cavium Networks
10 */
11
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/platform_device.h>
15#include <linux/device.h>
16#include <linux/hw_random.h>
17#include <linux/io.h>
18
19#include <asm/octeon/octeon.h>
20#include <asm/octeon/cvmx-rnm-defs.h>
21
22struct octeon_rng {
23 struct hwrng ops;
24 void __iomem *control_status;
25 void __iomem *result;
26};
27
28static int octeon_rng_init(struct hwrng *rng)
29{
30 union cvmx_rnm_ctl_status ctl;
31 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
32
33 ctl.u64 = 0;
34 ctl.s.ent_en = 1; /* Enable the entropy source. */
35 ctl.s.rng_en = 1; /* Enable the RNG hardware. */
36 cvmx_write_csr((u64)p->control_status, ctl.u64);
37 return 0;
38}
39
40static void octeon_rng_cleanup(struct hwrng *rng)
41{
42 union cvmx_rnm_ctl_status ctl;
43 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
44
45 ctl.u64 = 0;
46 /* Disable everything. */
47 cvmx_write_csr((u64)p->control_status, ctl.u64);
48}
49
50static int octeon_rng_data_read(struct hwrng *rng, u32 *data)
51{
52 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
53
54 *data = cvmx_read64_uint32((u64)p->result);
55 return sizeof(u32);
56}
57
58static int __devinit octeon_rng_probe(struct platform_device *pdev)
59{
60 struct resource *res_ports;
61 struct resource *res_result;
62 struct octeon_rng *rng;
63 int ret;
64 struct hwrng ops = {
65 .name = "octeon",
66 .init = octeon_rng_init,
67 .cleanup = octeon_rng_cleanup,
68 .data_read = octeon_rng_data_read
69 };
70
71 rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
72 if (!rng)
73 return -ENOMEM;
74
75 res_ports = platform_get_resource(pdev, IORESOURCE_MEM, 0);
76 if (!res_ports)
77 goto err_ports;
78
79 res_result = platform_get_resource(pdev, IORESOURCE_MEM, 1);
80 if (!res_result)
81 goto err_ports;
82
83
84 rng->control_status = devm_ioremap_nocache(&pdev->dev,
85 res_ports->start,
86 sizeof(u64));
87 if (!rng->control_status)
88 goto err_ports;
89
90 rng->result = devm_ioremap_nocache(&pdev->dev,
91 res_result->start,
92 sizeof(u64));
93 if (!rng->result)
94 goto err_r;
95
96 rng->ops = ops;
97
98 dev_set_drvdata(&pdev->dev, &rng->ops);
99 ret = hwrng_register(&rng->ops);
100 if (ret)
101 goto err;
102
103 dev_info(&pdev->dev, "Octeon Random Number Generator\n");
104
105 return 0;
106err:
107 devm_iounmap(&pdev->dev, rng->control_status);
108err_r:
109 devm_iounmap(&pdev->dev, rng->result);
110err_ports:
111 devm_kfree(&pdev->dev, rng);
112 return -ENOENT;
113}
114
115static int __exit octeon_rng_remove(struct platform_device *pdev)
116{
117 struct hwrng *rng = dev_get_drvdata(&pdev->dev);
118
119 hwrng_unregister(rng);
120
121 return 0;
122}
123
124static struct platform_driver octeon_rng_driver = {
125 .driver = {
126 .name = "octeon_rng",
127 .owner = THIS_MODULE,
128 },
129 .probe = octeon_rng_probe,
130 .remove = __exit_p(octeon_rng_remove),
131};
132
133static int __init octeon_rng_mod_init(void)
134{
135 return platform_driver_register(&octeon_rng_driver);
136}
137
138static void __exit octeon_rng_mod_exit(void)
139{
140 platform_driver_unregister(&octeon_rng_driver);
141}
142
143module_init(octeon_rng_mod_init);
144module_exit(octeon_rng_mod_exit);
145
146MODULE_AUTHOR("David Daney");
147MODULE_LICENSE("GPL");