]>
Commit | Line | Data |
---|---|---|
ef5d8627 MB |
1 | /* |
2 | * RNG driver for AMD Geode RNGs | |
3 | * | |
4 | * Copyright 2005 (c) MontaVista Software, Inc. | |
5 | * | |
6 | * with the majority of the code coming from: | |
7 | * | |
8 | * Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG) | |
9 | * (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com> | |
10 | * | |
11 | * derived from | |
12 | * | |
13 | * Hardware driver for the AMD 768 Random Number Generator (RNG) | |
14 | * (c) Copyright 2001 Red Hat Inc <alan@redhat.com> | |
15 | * | |
16 | * derived from | |
17 | * | |
18 | * Hardware driver for Intel i810 Random Number Generator (RNG) | |
19 | * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com> | |
20 | * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com> | |
21 | * | |
22 | * This file is licensed under the terms of the GNU General Public | |
23 | * License version 2. This program is licensed "as is" without any | |
24 | * warranty of any kind, whether express or implied. | |
25 | */ | |
26 | ||
27 | #include <linux/module.h> | |
28 | #include <linux/kernel.h> | |
29 | #include <linux/pci.h> | |
30 | #include <linux/hw_random.h> | |
31 | #include <asm/io.h> | |
32 | ||
33 | ||
34 | #define PFX KBUILD_MODNAME ": " | |
35 | ||
36 | #define GEODE_RNG_DATA_REG 0x50 | |
37 | #define GEODE_RNG_STATUS_REG 0x54 | |
38 | ||
39 | /* | |
40 | * Data for PCI driver interface | |
41 | * | |
42 | * This data only exists for exporting the supported | |
43 | * PCI ids via MODULE_DEVICE_TABLE. We do not actually | |
44 | * register a pci_driver, because someone else might one day | |
45 | * want to register another driver on the same PCI id. | |
46 | */ | |
47 | static const struct pci_device_id pci_tbl[] = { | |
48 | { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES, | |
49 | PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, | |
50 | { 0, }, /* terminate list */ | |
51 | }; | |
52 | MODULE_DEVICE_TABLE(pci, pci_tbl); | |
53 | ||
54 | ||
55 | static int geode_rng_data_read(struct hwrng *rng, u32 *data) | |
56 | { | |
57 | void __iomem *mem = (void __iomem *)rng->priv; | |
58 | ||
59 | *data = readl(mem + GEODE_RNG_DATA_REG); | |
60 | ||
61 | return 4; | |
62 | } | |
63 | ||
64 | static int geode_rng_data_present(struct hwrng *rng) | |
65 | { | |
66 | void __iomem *mem = (void __iomem *)rng->priv; | |
67 | ||
68 | return !!(readl(mem + GEODE_RNG_STATUS_REG)); | |
69 | } | |
70 | ||
71 | ||
72 | static struct hwrng geode_rng = { | |
73 | .name = "geode", | |
74 | .data_present = geode_rng_data_present, | |
75 | .data_read = geode_rng_data_read, | |
76 | }; | |
77 | ||
78 | ||
79 | static int __init mod_init(void) | |
80 | { | |
81 | int err = -ENODEV; | |
82 | struct pci_dev *pdev = NULL; | |
83 | const struct pci_device_id *ent; | |
84 | void __iomem *mem; | |
85 | unsigned long rng_base; | |
86 | ||
87 | for_each_pci_dev(pdev) { | |
88 | ent = pci_match_id(pci_tbl, pdev); | |
89 | if (ent) | |
90 | goto found; | |
91 | } | |
92 | /* Device not found. */ | |
93 | goto out; | |
94 | ||
95 | found: | |
96 | rng_base = pci_resource_start(pdev, 0); | |
97 | if (rng_base == 0) | |
98 | goto out; | |
99 | err = -ENOMEM; | |
100 | mem = ioremap(rng_base, 0x58); | |
101 | if (!mem) | |
102 | goto out; | |
103 | geode_rng.priv = (unsigned long)mem; | |
104 | ||
105 | printk(KERN_INFO "AMD Geode RNG detected\n"); | |
106 | err = hwrng_register(&geode_rng); | |
107 | if (err) { | |
108 | printk(KERN_ERR PFX "RNG registering failed (%d)\n", | |
109 | err); | |
072d3d1a | 110 | goto err_unmap; |
ef5d8627 MB |
111 | } |
112 | out: | |
113 | return err; | |
072d3d1a MB |
114 | |
115 | err_unmap: | |
116 | iounmap(mem); | |
117 | goto out; | |
ef5d8627 MB |
118 | } |
119 | ||
120 | static void __exit mod_exit(void) | |
121 | { | |
122 | void __iomem *mem = (void __iomem *)geode_rng.priv; | |
123 | ||
124 | hwrng_unregister(&geode_rng); | |
125 | iounmap(mem); | |
126 | } | |
127 | ||
56fb5fe9 | 128 | module_init(mod_init); |
ef5d8627 MB |
129 | module_exit(mod_exit); |
130 | ||
131 | MODULE_DESCRIPTION("H/W RNG driver for AMD Geode LX CPUs"); | |
132 | MODULE_LICENSE("GPL"); |