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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
/*
* omap-rng.c - RNG driver for TI OMAP CPU family
*
* Author: Deepak Saxena <dsaxena@plexity.net>
*
* Copyright 2005 (c) MontaVista Software, Inc.
*
* Mostly based on original driver:
*
* Copyright (C) 2005 Nokia Corporation
* Author: Juha Yrjölä <juha.yrjola@nokia.com>
*
* 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/err.h>
#include <linux/platform_device.h>
#include <linux/hw_random.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <asm/io.h>
#define RNG_OUT_REG 0x00 /* Output register */
#define RNG_STAT_REG 0x04 /* Status register
[0] = STAT_BUSY */
#define RNG_ALARM_REG 0x24 /* Alarm register
[7:0] = ALARM_COUNTER */
#define RNG_CONFIG_REG 0x28 /* Configuration register
[11:6] = RESET_COUNT
[5:3] = RING2_DELAY
[2:0] = RING1_DELAY */
#define RNG_REV_REG 0x3c /* Revision register
[7:0] = REV_NB */
#define RNG_MASK_REG 0x40 /* Mask and reset register
[2] = IT_EN
[1] = SOFTRESET
[0] = AUTOIDLE */
#define RNG_SYSSTATUS 0x44 /* System status
[0] = RESETDONE */
/**
* struct omap_rng_private_data - RNG IP block-specific data
* @base: virtual address of the beginning of the RNG IP block registers
* @mem_res: struct resource * for the IP block registers physical memory
*/
struct omap_rng_private_data {
void __iomem *base;
struct resource *mem_res;
};
static inline u32 omap_rng_read_reg(struct omap_rng_private_data *priv, int reg)
{
return __raw_readl(priv->base + reg);
}
static inline void omap_rng_write_reg(struct omap_rng_private_data *priv,
int reg, u32 val)
{
__raw_writel(val, priv->base + reg);
}
static int omap_rng_data_present(struct hwrng *rng, int wait)
{
struct omap_rng_private_data *priv;
int data, i;
priv = (struct omap_rng_private_data *)rng->priv;
for (i = 0; i < 20; i++) {
data = omap_rng_read_reg(priv, RNG_STAT_REG) ? 0 : 1;
if (data || !wait)
break;
/* RNG produces data fast enough (2+ MBit/sec, even
* during "rngtest" loads, that these delays don't
* seem to trigger. We *could* use the RNG IRQ, but
* that'd be higher overhead ... so why bother?
*/
udelay(10);
}
return data;
}
static int omap_rng_data_read(struct hwrng *rng, u32 *data)
{
struct omap_rng_private_data *priv;
priv = (struct omap_rng_private_data *)rng->priv;
*data = omap_rng_read_reg(priv, RNG_OUT_REG);
return sizeof(u32);
}
static struct hwrng omap_rng_ops = {
.name = "omap",
.data_present = omap_rng_data_present,
.data_read = omap_rng_data_read,
};
static int omap_rng_probe(struct platform_device *pdev)
{
struct omap_rng_private_data *priv;
int ret;
priv = kzalloc(sizeof(struct omap_rng_private_data), GFP_KERNEL);
if (!priv) {
dev_err(&pdev->dev, "could not allocate memory\n");
return -ENOMEM;
};
omap_rng_ops.priv = (unsigned long)priv;
dev_set_drvdata(&pdev->dev, priv);
priv->mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!priv->mem_res) {
ret = -ENOENT;
goto err_ioremap;
}
priv->base = devm_ioremap_resource(&pdev->dev, priv->mem_res);
if (IS_ERR(priv->base)) {
ret = PTR_ERR(priv->base);
goto err_ioremap;
}
dev_set_drvdata(&pdev->dev, priv);
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
ret = hwrng_register(&omap_rng_ops);
if (ret)
goto err_register;
dev_info(&pdev->dev, "OMAP Random Number Generator ver. %02x\n",
omap_rng_read_reg(priv, RNG_REV_REG));
omap_rng_write_reg(priv, RNG_MASK_REG, 0x1);
return 0;
err_register:
priv->base = NULL;
pm_runtime_disable(&pdev->dev);
err_ioremap:
kfree(priv);
return ret;
}
static int __exit omap_rng_remove(struct platform_device *pdev)
{
struct omap_rng_private_data *priv = dev_get_drvdata(&pdev->dev);
hwrng_unregister(&omap_rng_ops);
omap_rng_write_reg(priv, RNG_MASK_REG, 0x0);
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
release_mem_region(priv->mem_res->start, resource_size(priv->mem_res));
kfree(priv);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int omap_rng_suspend(struct device *dev)
{
struct omap_rng_private_data *priv = dev_get_drvdata(dev);
omap_rng_write_reg(priv, RNG_MASK_REG, 0x0);
pm_runtime_put_sync(dev);
return 0;
}
static int omap_rng_resume(struct device *dev)
{
struct omap_rng_private_data *priv = dev_get_drvdata(dev);
pm_runtime_get_sync(dev);
omap_rng_write_reg(priv, RNG_MASK_REG, 0x1);
return 0;
}
static SIMPLE_DEV_PM_OPS(omap_rng_pm, omap_rng_suspend, omap_rng_resume);
#define OMAP_RNG_PM (&omap_rng_pm)
#else
#define OMAP_RNG_PM NULL
#endif
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:omap_rng");
static struct platform_driver omap_rng_driver = {
.driver = {
.name = "omap_rng",
.owner = THIS_MODULE,
.pm = OMAP_RNG_PM,
},
.probe = omap_rng_probe,
.remove = __exit_p(omap_rng_remove),
};
static int __init omap_rng_init(void)
{
return platform_driver_register(&omap_rng_driver);
}
static void __exit omap_rng_exit(void)
{
platform_driver_unregister(&omap_rng_driver);
}
module_init(omap_rng_init);
module_exit(omap_rng_exit);
MODULE_AUTHOR("Deepak Saxena (and others)");
MODULE_LICENSE("GPL");
|
