diff options
author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2009-03-28 16:29:51 -0400 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-03-28 16:29:51 -0400 |
commit | ed40d0c472b136682b2fcba05f89762859c7374f (patch) | |
tree | 076b83a26bcd63d6158463735dd34c10bbc591dc /drivers/char/hw_random | |
parent | 9e495834e59ca9b29f1a1f63b9f5533bb022ac49 (diff) | |
parent | 5d80f8e5a9dc9c9a94d4aeaa567e219a808b8a4a (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/Kconfig | 14 | ||||
-rw-r--r-- | drivers/char/hw_random/Makefile | 1 | ||||
-rw-r--r-- | drivers/char/hw_random/timeriomem-rng.c | 151 |
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 | ||
23 | config 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 | |||
23 | config HW_RANDOM_INTEL | 37 | config 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 | ||
5 | obj-$(CONFIG_HW_RANDOM) += rng-core.o | 5 | obj-$(CONFIG_HW_RANDOM) += rng-core.o |
6 | rng-core-y := core.o | 6 | rng-core-y := core.o |
7 | obj-$(CONFIG_HW_RANDOM_TIMERIOMEM) += timeriomem-rng.o | ||
7 | obj-$(CONFIG_HW_RANDOM_INTEL) += intel-rng.o | 8 | obj-$(CONFIG_HW_RANDOM_INTEL) += intel-rng.o |
8 | obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o | 9 | obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o |
9 | obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o | 10 | obj-$(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 | |||
34 | static struct timeriomem_rng_data *timeriomem_rng_data; | ||
35 | |||
36 | static void timeriomem_rng_trigger(unsigned long); | ||
37 | static 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 | */ | ||
42 | static 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 | |||
55 | static 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 | |||
78 | static void timeriomem_rng_trigger(unsigned long dummy) | ||
79 | { | ||
80 | timeriomem_rng_data->present = 1; | ||
81 | complete(&timeriomem_rng_data->completion); | ||
82 | } | ||
83 | |||
84 | static 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 | |||
91 | static 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 | |||
119 | static 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 | |||
127 | static 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 | |||
136 | static int __init timeriomem_rng_init(void) | ||
137 | { | ||
138 | return platform_driver_register(&timeriomem_rng_driver); | ||
139 | } | ||
140 | |||
141 | static void __exit timeriomem_rng_exit(void) | ||
142 | { | ||
143 | platform_driver_unregister(&timeriomem_rng_driver); | ||
144 | } | ||
145 | |||
146 | module_init(timeriomem_rng_init); | ||
147 | module_exit(timeriomem_rng_exit); | ||
148 | |||
149 | MODULE_LICENSE("GPL"); | ||
150 | MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>"); | ||
151 | MODULE_DESCRIPTION("Timer IOMEM H/W RNG driver"); | ||