tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
pasemi: hardware rng driver
Driver for the on-chip hardware random number generator on PA Semi
PA6T-1682M.
Signed-off-by: Egor Martovetsky <egor@pasemi.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Kumar Gala <galak@gate.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
authored by
Olof Johansson
and committed by
Linus Torvalds
b8cb3448
4d355632
+171
+14
drivers/char/hw_random/Kconfig
+14
drivers/char/hw_random/Kconfig
···
91
91
module will be called omap-rng.
92
92
93
93
If unsure, say Y.
94
+
95
+
config HW_RANDOM_PASEMI
96
+
tristate "PA Semi HW Random Number Generator support"
97
+
depends on HW_RANDOM && PPC_PASEMI
98
+
default HW_RANDOM
99
+
---help---
100
+
This driver provides kernel-side support for the Random Number
101
+
Generator hardware found on PA6T-1682M processor.
102
+
103
+
To compile this driver as a module, choose M here: the
104
+
module will be called pasemi-rng.
105
+
106
+
If unsure, say Y.
107
+
+1
drivers/char/hw_random/Makefile
+1
drivers/char/hw_random/Makefile
+156
drivers/char/hw_random/pasemi-rng.c
+156
drivers/char/hw_random/pasemi-rng.c
···
1
+
/*
2
+
* Copyright (C) 2006-2007 PA Semi, Inc
3
+
*
4
+
* Maintained by: Olof Johansson <olof@lixom.net>
5
+
*
6
+
* Driver for the PWRficient onchip rng
7
+
*
8
+
* This program is free software; you can redistribute it and/or modify
9
+
* it under the terms of the GNU General Public License version 2 as
10
+
* published by the Free Software Foundation.
11
+
*
12
+
* This program is distributed in the hope that it will be useful,
13
+
* but WITHOUT ANY WARRANTY; without even the implied warranty of
14
+
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15
+
* GNU General Public License for more details.
16
+
*
17
+
* You should have received a copy of the GNU General Public License
18
+
* along with this program; if not, write to the Free Software
19
+
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20
+
*/
21
+
22
+
#include <linux/module.h>
23
+
#include <linux/kernel.h>
24
+
#include <linux/platform_device.h>
25
+
#include <linux/hw_random.h>
26
+
#include <asm/of_platform.h>
27
+
#include <asm/io.h>
28
+
29
+
#define SDCRNG_CTL_REG 0x00
30
+
#define SDCRNG_CTL_FVLD_M 0x0000f000
31
+
#define SDCRNG_CTL_FVLD_S 12
32
+
#define SDCRNG_CTL_KSZ 0x00000800
33
+
#define SDCRNG_CTL_RSRC_CRG 0x00000010
34
+
#define SDCRNG_CTL_RSRC_RRG 0x00000000
35
+
#define SDCRNG_CTL_CE 0x00000004
36
+
#define SDCRNG_CTL_RE 0x00000002
37
+
#define SDCRNG_CTL_DR 0x00000001
38
+
#define SDCRNG_CTL_SELECT_RRG_RNG (SDCRNG_CTL_RE | SDCRNG_CTL_RSRC_RRG)
39
+
#define SDCRNG_CTL_SELECT_CRG_RNG (SDCRNG_CTL_CE | SDCRNG_CTL_RSRC_CRG)
40
+
#define SDCRNG_VAL_REG 0x20
41
+
42
+
#define MODULE_NAME "pasemi_rng"
43
+
44
+
static int pasemi_rng_data_present(struct hwrng *rng)
45
+
{
46
+
void __iomem *rng_regs = (void __iomem *)rng->priv;
47
+
48
+
return (in_le32(rng_regs + SDCRNG_CTL_REG)
49
+
& SDCRNG_CTL_FVLD_M) ? 1 : 0;
50
+
}
51
+
52
+
static int pasemi_rng_data_read(struct hwrng *rng, u32 *data)
53
+
{
54
+
void __iomem *rng_regs = (void __iomem *)rng->priv;
55
+
*data = in_le32(rng_regs + SDCRNG_VAL_REG);
56
+
return 4;
57
+
}
58
+
59
+
static int pasemi_rng_init(struct hwrng *rng)
60
+
{
61
+
void __iomem *rng_regs = (void __iomem *)rng->priv;
62
+
u32 ctl;
63
+
64
+
ctl = SDCRNG_CTL_DR | SDCRNG_CTL_SELECT_RRG_RNG | SDCRNG_CTL_KSZ;
65
+
out_le32(rng_regs + SDCRNG_CTL_REG, ctl);
66
+
out_le32(rng_regs + SDCRNG_CTL_REG, ctl & ~SDCRNG_CTL_DR);
67
+
68
+
return 0;
69
+
}
70
+
71
+
static void pasemi_rng_cleanup(struct hwrng *rng)
72
+
{
73
+
void __iomem *rng_regs = (void __iomem *)rng->priv;
74
+
u32 ctl;
75
+
76
+
ctl = SDCRNG_CTL_RE | SDCRNG_CTL_CE;
77
+
out_le32(rng_regs + SDCRNG_CTL_REG,
78
+
in_le32(rng_regs + SDCRNG_CTL_REG) & ~ctl);
79
+
}
80
+
81
+
static struct hwrng pasemi_rng = {
82
+
.name = MODULE_NAME,
83
+
.init = pasemi_rng_init,
84
+
.cleanup = pasemi_rng_cleanup,
85
+
.data_present = pasemi_rng_data_present,
86
+
.data_read = pasemi_rng_data_read,
87
+
};
88
+
89
+
static int __devinit rng_probe(struct of_device *ofdev,
90
+
const struct of_device_id *match)
91
+
{
92
+
void __iomem *rng_regs;
93
+
struct device_node *rng_np = ofdev->node;
94
+
struct resource res;
95
+
int err = 0;
96
+
97
+
err = of_address_to_resource(rng_np, 0, &res);
98
+
if (err)
99
+
return -ENODEV;
100
+
101
+
rng_regs = ioremap(res.start, 0x100);
102
+
103
+
if (!rng_regs)
104
+
return -ENOMEM;
105
+
106
+
pasemi_rng.priv = (unsigned long)rng_regs;
107
+
108
+
printk(KERN_INFO "Registering PA Semi RNG\n");
109
+
110
+
err = hwrng_register(&pasemi_rng);
111
+
112
+
if (err)
113
+
iounmap(rng_regs);
114
+
115
+
return err;
116
+
}
117
+
118
+
static int __devexit rng_remove(struct of_device *dev)
119
+
{
120
+
void __iomem *rng_regs = (void __iomem *)pasemi_rng.priv;
121
+
122
+
hwrng_unregister(&pasemi_rng);
123
+
iounmap(rng_regs);
124
+
125
+
return 0;
126
+
}
127
+
128
+
static struct of_device_id rng_match[] = {
129
+
{
130
+
.compatible = "1682m-rng",
131
+
},
132
+
{},
133
+
};
134
+
135
+
static struct of_platform_driver rng_driver = {
136
+
.name = "pasemi-rng",
137
+
.match_table = rng_match,
138
+
.probe = rng_probe,
139
+
.remove = rng_remove,
140
+
};
141
+
142
+
static int __init rng_init(void)
143
+
{
144
+
return of_register_platform_driver(&rng_driver);
145
+
}
146
+
module_init(rng_init);
147
+
148
+
static void __exit rng_exit(void)
149
+
{
150
+
of_unregister_platform_driver(&rng_driver);
151
+
}
152
+
module_exit(rng_exit);
153
+
154
+
MODULE_LICENSE("GPL");
155
+
MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>");
156
+
MODULE_DESCRIPTION("H/W RNG driver for PA Semi processor");