1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
/*
* omap3-rom-rng.c - RNG driver for TI OMAP3 CPU family
*
* Copyright (C) 2009 Nokia Corporation
* Author: Juha Yrjola <juha.yrjola@solidboot.com>
*
* Copyright (C) 2013 Pali Rohár <pali@kernel.org>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/random.h>
#include <linux/hw_random.h>
#include <linux/workqueue.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#define RNG_RESET 0x01
#define RNG_GEN_PRNG_HW_INIT 0x02
#define RNG_GEN_HW 0x08
struct omap_rom_rng {
struct clk *clk;
struct device *dev;
struct hwrng ops;
u32 (*rom_rng_call)(u32 ptr, u32 count, u32 flag);
};
static int omap3_rom_rng_read(struct hwrng *rng, void *data, size_t max, bool w)
{
struct omap_rom_rng *ddata;
u32 ptr;
int r;
ddata = (struct omap_rom_rng *)rng->priv;
r = pm_runtime_get_sync(ddata->dev);
if (r < 0) {
pm_runtime_put_noidle(ddata->dev);
return r;
}
ptr = virt_to_phys(data);
r = ddata->rom_rng_call(ptr, 4, RNG_GEN_HW);
if (r != 0)
r = -EINVAL;
else
r = 4;
pm_runtime_mark_last_busy(ddata->dev);
pm_runtime_put_autosuspend(ddata->dev);
return r;
}
static int __maybe_unused omap_rom_rng_runtime_suspend(struct device *dev)
{
struct omap_rom_rng *ddata;
int r;
ddata = dev_get_drvdata(dev);
r = ddata->rom_rng_call(0, 0, RNG_RESET);
if (r != 0)
dev_err(dev, "reset failed: %d\n", r);
clk_disable_unprepare(ddata->clk);
return 0;
}
static int __maybe_unused omap_rom_rng_runtime_resume(struct device *dev)
{
struct omap_rom_rng *ddata;
int r;
ddata = dev_get_drvdata(dev);
r = clk_prepare_enable(ddata->clk);
if (r < 0)
return r;
r = ddata->rom_rng_call(0, 0, RNG_GEN_PRNG_HW_INIT);
if (r != 0) {
clk_disable_unprepare(ddata->clk);
dev_err(dev, "HW init failed: %d\n", r);
return -EIO;
}
return 0;
}
static void omap_rom_rng_finish(void *data)
{
struct omap_rom_rng *ddata = data;
pm_runtime_dont_use_autosuspend(ddata->dev);
pm_runtime_disable(ddata->dev);
}
static int omap3_rom_rng_probe(struct platform_device *pdev)
{
struct omap_rom_rng *ddata;
int ret = 0;
ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
if (!ddata)
return -ENOMEM;
ddata->dev = &pdev->dev;
ddata->ops.priv = (unsigned long)ddata;
ddata->ops.name = "omap3-rom";
ddata->ops.read = of_device_get_match_data(&pdev->dev);
ddata->ops.quality = 900;
if (!ddata->ops.read) {
dev_err(&pdev->dev, "missing rom code handler\n");
return -ENODEV;
}
dev_set_drvdata(ddata->dev, ddata);
ddata->rom_rng_call = pdev->dev.platform_data;
if (!ddata->rom_rng_call) {
dev_err(ddata->dev, "rom_rng_call is NULL\n");
return -EINVAL;
}
ddata->clk = devm_clk_get(ddata->dev, "ick");
if (IS_ERR(ddata->clk)) {
dev_err(ddata->dev, "unable to get RNG clock\n");
return PTR_ERR(ddata->clk);
}
pm_runtime_enable(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev, 500);
pm_runtime_use_autosuspend(&pdev->dev);
ret = devm_add_action_or_reset(ddata->dev, omap_rom_rng_finish,
ddata);
if (ret)
return ret;
return devm_hwrng_register(ddata->dev, &ddata->ops);
}
static const struct of_device_id omap_rom_rng_match[] = {
{ .compatible = "nokia,n900-rom-rng", .data = omap3_rom_rng_read, },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, omap_rom_rng_match);
static const struct dev_pm_ops omap_rom_rng_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(omap_rom_rng_runtime_suspend,
omap_rom_rng_runtime_resume)
};
static struct platform_driver omap3_rom_rng_driver = {
.driver = {
.name = "omap3-rom-rng",
.of_match_table = omap_rom_rng_match,
.pm = &omap_rom_rng_pm_ops,
},
.probe = omap3_rom_rng_probe,
};
module_platform_driver(omap3_rom_rng_driver);
MODULE_ALIAS("platform:omap3-rom-rng");
MODULE_AUTHOR("Juha Yrjola");
MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
MODULE_LICENSE("GPL");
|
