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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2009-03-28 16:29:51 -0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2009-03-28 16:29:51 -0400
commited40d0c472b136682b2fcba05f89762859c7374f (patch)
tree076b83a26bcd63d6158463735dd34c10bbc591dc /drivers/char/hw_random
parent9e495834e59ca9b29f1a1f63b9f5533bb022ac49 (diff)
parent5d80f8e5a9dc9c9a94d4aeaa567e219a808b8a4a (diff)
Merge branch 'origin' into devel
Conflicts: sound/soc/pxa/pxa2xx-i2s.c
Diffstat (limited to 'drivers/char/hw_random')
-rw-r--r--drivers/char/hw_random/Kconfig14
-rw-r--r--drivers/char/hw_random/Makefile1
-rw-r--r--drivers/char/hw_random/timeriomem-rng.c151
3 files changed, 166 insertions, 0 deletions
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 8822eca58ffa..5fab6470f4b2 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -20,6 +20,20 @@ config HW_RANDOM
20 20
21 If unsure, say Y. 21 If unsure, say Y.
22 22
23config HW_RANDOM_TIMERIOMEM
24 tristate "Timer IOMEM HW Random Number Generator support"
25 depends on HW_RANDOM && HAS_IOMEM
26 ---help---
27 This driver provides kernel-side support for a generic Random
28 Number Generator used by reading a 'dumb' iomem address that
29 is to be read no faster than, for example, once a second;
30 the default FPGA bitstream on the TS-7800 has such functionality.
31
32 To compile this driver as a module, choose M here: the
33 module will be called timeriomem-rng.
34
35 If unsure, say Y.
36
23config HW_RANDOM_INTEL 37config HW_RANDOM_INTEL
24 tristate "Intel HW Random Number Generator support" 38 tristate "Intel HW Random Number Generator support"
25 depends on HW_RANDOM && (X86 || IA64) && PCI 39 depends on HW_RANDOM && (X86 || IA64) && PCI
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index b6effb7522c2..e81d21a5f28f 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -4,6 +4,7 @@
4 4
5obj-$(CONFIG_HW_RANDOM) += rng-core.o 5obj-$(CONFIG_HW_RANDOM) += rng-core.o
6rng-core-y := core.o 6rng-core-y := core.o
7obj-$(CONFIG_HW_RANDOM_TIMERIOMEM) += timeriomem-rng.o
7obj-$(CONFIG_HW_RANDOM_INTEL) += intel-rng.o 8obj-$(CONFIG_HW_RANDOM_INTEL) += intel-rng.o
8obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o 9obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o
9obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o 10obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
diff --git a/drivers/char/hw_random/timeriomem-rng.c b/drivers/char/hw_random/timeriomem-rng.c
new file mode 100644
index 000000000000..10ad41be5897
--- /dev/null
+++ b/drivers/char/hw_random/timeriomem-rng.c
@@ -0,0 +1,151 @@
1/*
2 * drivers/char/hw_random/timeriomem-rng.c
3 *
4 * Copyright (C) 2009 Alexander Clouter <alex@digriz.org.uk>
5 *
6 * Derived from drivers/char/hw_random/omap-rng.c
7 * Copyright 2005 (c) MontaVista Software, Inc.
8 * Author: Deepak Saxena <dsaxena@plexity.net>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 * Overview:
15 * This driver is useful for platforms that have an IO range that provides
16 * periodic random data from a single IO memory address. All the platform
17 * has to do is provide the address and 'wait time' that new data becomes
18 * available.
19 *
20 * TODO: add support for reading sizes other than 32bits and masking
21 */
22
23#include <linux/module.h>
24#include <linux/kernel.h>
25#include <linux/platform_device.h>
26#include <linux/hw_random.h>
27#include <linux/io.h>
28#include <linux/timeriomem-rng.h>
29#include <linux/jiffies.h>
30#include <linux/sched.h>
31#include <linux/timer.h>
32#include <linux/completion.h>
33
34static struct timeriomem_rng_data *timeriomem_rng_data;
35
36static void timeriomem_rng_trigger(unsigned long);
37static DEFINE_TIMER(timeriomem_rng_timer, timeriomem_rng_trigger, 0, 0);
38
39/*
40 * have data return 1, however return 0 if we have nothing
41 */
42static int timeriomem_rng_data_present(struct hwrng *rng, int wait)
43{
44 if (rng->priv == 0)
45 return 1;
46
47 if (!wait || timeriomem_rng_data->present)
48 return timeriomem_rng_data->present;
49
50 wait_for_completion(&timeriomem_rng_data->completion);
51
52 return 1;
53}
54
55static int timeriomem_rng_data_read(struct hwrng *rng, u32 *data)
56{
57 unsigned long cur;
58 s32 delay;
59
60 *data = readl(timeriomem_rng_data->address);
61
62 if (rng->priv != 0) {
63 cur = jiffies;
64
65 delay = cur - timeriomem_rng_timer.expires;
66 delay = rng->priv - (delay % rng->priv);
67
68 timeriomem_rng_timer.expires = cur + delay;
69 timeriomem_rng_data->present = 0;
70
71 init_completion(&timeriomem_rng_data->completion);
72 add_timer(&timeriomem_rng_timer);
73 }
74
75 return 4;
76}
77
78static void timeriomem_rng_trigger(unsigned long dummy)
79{
80 timeriomem_rng_data->present = 1;
81 complete(&timeriomem_rng_data->completion);
82}
83
84static struct hwrng timeriomem_rng_ops = {
85 .name = "timeriomem",
86 .data_present = timeriomem_rng_data_present,
87 .data_read = timeriomem_rng_data_read,
88 .priv = 0,
89};
90
91static int __init timeriomem_rng_probe(struct platform_device *pdev)
92{
93 int ret;
94
95 timeriomem_rng_data = pdev->dev.platform_data;
96
97 if (timeriomem_rng_data->period != 0
98 && usecs_to_jiffies(timeriomem_rng_data->period) > 0) {
99 timeriomem_rng_timer.expires = jiffies;
100
101 timeriomem_rng_ops.priv = usecs_to_jiffies(
102 timeriomem_rng_data->period);
103 }
104 timeriomem_rng_data->present = 1;
105
106 ret = hwrng_register(&timeriomem_rng_ops);
107 if (ret) {
108 dev_err(&pdev->dev, "problem registering\n");
109 return ret;
110 }
111
112 dev_info(&pdev->dev, "32bits from 0x%p @ %dus\n",
113 timeriomem_rng_data->address,
114 timeriomem_rng_data->period);
115
116 return 0;
117}
118
119static int __devexit timeriomem_rng_remove(struct platform_device *pdev)
120{
121 del_timer_sync(&timeriomem_rng_timer);
122 hwrng_unregister(&timeriomem_rng_ops);
123
124 return 0;
125}
126
127static struct platform_driver timeriomem_rng_driver = {
128 .driver = {
129 .name = "timeriomem_rng",
130 .owner = THIS_MODULE,
131 },
132 .probe = timeriomem_rng_probe,
133 .remove = __devexit_p(timeriomem_rng_remove),
134};
135
136static int __init timeriomem_rng_init(void)
137{
138 return platform_driver_register(&timeriomem_rng_driver);
139}
140
141static void __exit timeriomem_rng_exit(void)
142{
143 platform_driver_unregister(&timeriomem_rng_driver);
144}
145
146module_init(timeriomem_rng_init);
147module_exit(timeriomem_rng_exit);
148
149MODULE_LICENSE("GPL");
150MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
151MODULE_DESCRIPTION("Timer IOMEM H/W RNG driver");