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authorMichael Buesch <mb@bu3sch.de>2006-06-26 03:25:01 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 12:58:19 -0400
commitef5d862734b84239e0140319a95fb0bbff5ef394 (patch)
tree29b39c830c9e55f3d78abfd9e7f57ef01052a1bc /drivers/char/hw_random/geode-rng.c
parent96d63c0297ccfd6d9059c614b3f5555d9441a2b3 (diff)
[PATCH] Add Geode HW RNG driver
Signed-off-by: Michael Buesch <mb@bu3sch.de> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/char/hw_random/geode-rng.c')
-rw-r--r--drivers/char/hw_random/geode-rng.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/drivers/char/hw_random/geode-rng.c b/drivers/char/hw_random/geode-rng.c
new file mode 100644
index 000000000000..be61f22ee7bb
--- /dev/null
+++ b/drivers/char/hw_random/geode-rng.c
@@ -0,0 +1,128 @@
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 */
47static 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};
52MODULE_DEVICE_TABLE(pci, pci_tbl);
53
54
55static 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
64static 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
72static struct hwrng geode_rng = {
73 .name = "geode",
74 .data_present = geode_rng_data_present,
75 .data_read = geode_rng_data_read,
76};
77
78
79static 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
95found:
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);
110 goto out;
111 }
112out:
113 return err;
114}
115
116static void __exit mod_exit(void)
117{
118 void __iomem *mem = (void __iomem *)geode_rng.priv;
119
120 hwrng_unregister(&geode_rng);
121 iounmap(mem);
122}
123
124subsys_initcall(mod_init);
125module_exit(mod_exit);
126
127MODULE_DESCRIPTION("H/W RNG driver for AMD Geode LX CPUs");
128MODULE_LICENSE("GPL");