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f7557dc8 DD |
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> | |
5a0e3ad6 | 18 | #include <linux/gfp.h> |
f7557dc8 DD |
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
134 | static int __init octeon_rng_mod_init(void) | |
135 | { | |
136 | return platform_driver_register(&octeon_rng_driver); | |
137 | } | |
138 | ||
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"); |