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 #include <linux/gfp.h>
19
20 #include <asm/octeon/octeon.h>
21 #include <asm/octeon/cvmx-rnm-defs.h>
22
23 struct octeon_rng {
24 struct hwrng ops;
25 void __iomem *control_status;
26 void __iomem *result;
27 };
28
octeon_rng_init(struct hwrng * rng)29 static int octeon_rng_init(struct hwrng *rng)
30 {
31 union cvmx_rnm_ctl_status ctl;
32 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
33
34 ctl.u64 = 0;
35 ctl.s.ent_en = 1; /* Enable the entropy source. */
36 ctl.s.rng_en = 1; /* Enable the RNG hardware. */
37 cvmx_write_csr((u64)p->control_status, ctl.u64);
38 return 0;
39 }
40
octeon_rng_cleanup(struct hwrng * rng)41 static void octeon_rng_cleanup(struct hwrng *rng)
42 {
43 union cvmx_rnm_ctl_status ctl;
44 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
45
46 ctl.u64 = 0;
47 /* Disable everything. */
48 cvmx_write_csr((u64)p->control_status, ctl.u64);
49 }
50
octeon_rng_data_read(struct hwrng * rng,u32 * data)51 static int octeon_rng_data_read(struct hwrng *rng, u32 *data)
52 {
53 struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
54
55 *data = cvmx_read64_uint32((u64)p->result);
56 return sizeof(u32);
57 }
58
octeon_rng_probe(struct platform_device * pdev)59 static int __devinit octeon_rng_probe(struct platform_device *pdev)
60 {
61 struct resource *res_ports;
62 struct resource *res_result;
63 struct octeon_rng *rng;
64 int ret;
65 struct hwrng ops = {
66 .name = "octeon",
67 .init = octeon_rng_init,
68 .cleanup = octeon_rng_cleanup,
69 .data_read = octeon_rng_data_read
70 };
71
72 rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
73 if (!rng)
74 return -ENOMEM;
75
76 res_ports = platform_get_resource(pdev, IORESOURCE_MEM, 0);
77 if (!res_ports)
78 goto err_ports;
79
80 res_result = platform_get_resource(pdev, IORESOURCE_MEM, 1);
81 if (!res_result)
82 goto err_ports;
83
84
85 rng->control_status = devm_ioremap_nocache(&pdev->dev,
86 res_ports->start,
87 sizeof(u64));
88 if (!rng->control_status)
89 goto err_ports;
90
91 rng->result = devm_ioremap_nocache(&pdev->dev,
92 res_result->start,
93 sizeof(u64));
94 if (!rng->result)
95 goto err_r;
96
97 rng->ops = ops;
98
99 dev_set_drvdata(&pdev->dev, &rng->ops);
100 ret = hwrng_register(&rng->ops);
101 if (ret)
102 goto err;
103
104 dev_info(&pdev->dev, "Octeon Random Number Generator\n");
105
106 return 0;
107 err:
108 devm_iounmap(&pdev->dev, rng->control_status);
109 err_r:
110 devm_iounmap(&pdev->dev, rng->result);
111 err_ports:
112 devm_kfree(&pdev->dev, rng);
113 return -ENOENT;
114 }
115
octeon_rng_remove(struct platform_device * pdev)116 static int __exit octeon_rng_remove(struct platform_device *pdev)
117 {
118 struct hwrng *rng = dev_get_drvdata(&pdev->dev);
119
120 hwrng_unregister(rng);
121
122 return 0;
123 }
124
125 static struct platform_driver octeon_rng_driver = {
126 .driver = {
127 .name = "octeon_rng",
128 .owner = THIS_MODULE,
129 },
130 .probe = octeon_rng_probe,
131 .remove = __exit_p(octeon_rng_remove),
132 };
133
octeon_rng_mod_init(void)134 static int __init octeon_rng_mod_init(void)
135 {
136 return platform_driver_register(&octeon_rng_driver);
137 }
138
octeon_rng_mod_exit(void)139 static void __exit octeon_rng_mod_exit(void)
140 {
141 platform_driver_unregister(&octeon_rng_driver);
142 }
143
144 module_init(octeon_rng_mod_init);
145 module_exit(octeon_rng_mod_exit);
146
147 MODULE_AUTHOR("David Daney");
148 MODULE_LICENSE("GPL");
149