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
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for Mediatek Hardware Random Number Generator
*
* Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
*/
#define MTK_RNG_DEV KBUILD_MODNAME
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/hw_random.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
/* Runtime PM autosuspend timeout: */
#define RNG_AUTOSUSPEND_TIMEOUT 100
#define USEC_POLL 2
#define TIMEOUT_POLL 60
#define RNG_CTRL 0x00
#define RNG_EN BIT(0)
#define RNG_READY BIT(31)
#define RNG_DATA 0x08
#define to_mtk_rng(p) container_of(p, struct mtk_rng, rng)
struct mtk_rng {
void __iomem *base;
struct clk *clk;
struct hwrng rng;
};
static int mtk_rng_init(struct hwrng *rng)
{
struct mtk_rng *priv = to_mtk_rng(rng);
u32 val;
int err;
err = clk_prepare_enable(priv->clk);
if (err)
return err;
val = readl(priv->base + RNG_CTRL);
val |= RNG_EN;
writel(val, priv->base + RNG_CTRL);
return 0;
}
static void mtk_rng_cleanup(struct hwrng *rng)
{
struct mtk_rng *priv = to_mtk_rng(rng);
u32 val;
val = readl(priv->base + RNG_CTRL);
val &= ~RNG_EN;
writel(val, priv->base + RNG_CTRL);
clk_disable_unprepare(priv->clk);
}
static bool mtk_rng_wait_ready(struct hwrng *rng, bool wait)
{
struct mtk_rng *priv = to_mtk_rng(rng);
int ready;
ready = readl(priv->base + RNG_CTRL) & RNG_READY;
if (!ready && wait)
readl_poll_timeout_atomic(priv->base + RNG_CTRL, ready,
ready & RNG_READY, USEC_POLL,
TIMEOUT_POLL);
return !!(ready & RNG_READY);
}
static int mtk_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
{
struct mtk_rng *priv = to_mtk_rng(rng);
int retval = 0;
pm_runtime_get_sync((struct device *)priv->rng.priv);
while (max >= sizeof(u32)) {
if (!mtk_rng_wait_ready(rng, wait))
break;
*(u32 *)buf = readl(priv->base + RNG_DATA);
retval += sizeof(u32);
buf += sizeof(u32);
max -= sizeof(u32);
}
pm_runtime_mark_last_busy((struct device *)priv->rng.priv);
pm_runtime_put_sync_autosuspend((struct device *)priv->rng.priv);
return retval || !wait ? retval : -EIO;
}
static int mtk_rng_probe(struct platform_device *pdev)
{
int ret;
struct mtk_rng *priv;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->rng.name = pdev->name;
#ifndef CONFIG_PM
priv->rng.init = mtk_rng_init;
priv->rng.cleanup = mtk_rng_cleanup;
#endif
priv->rng.read = mtk_rng_read;
priv->rng.priv = (unsigned long)&pdev->dev;
priv->rng.quality = 900;
priv->clk = devm_clk_get(&pdev->dev, "rng");
if (IS_ERR(priv->clk)) {
ret = PTR_ERR(priv->clk);
dev_err(&pdev->dev, "no clock for device: %d\n", ret);
return ret;
}
priv->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
ret = devm_hwrng_register(&pdev->dev, &priv->rng);
if (ret) {
dev_err(&pdev->dev, "failed to register rng device: %d\n",
ret);
return ret;
}
dev_set_drvdata(&pdev->dev, priv);
pm_runtime_set_autosuspend_delay(&pdev->dev, RNG_AUTOSUSPEND_TIMEOUT);
pm_runtime_use_autosuspend(&pdev->dev);
devm_pm_runtime_enable(&pdev->dev);
dev_info(&pdev->dev, "registered RNG driver\n");
return 0;
}
#ifdef CONFIG_PM
static int mtk_rng_runtime_suspend(struct device *dev)
{
struct mtk_rng *priv = dev_get_drvdata(dev);
mtk_rng_cleanup(&priv->rng);
return 0;
}
static int mtk_rng_runtime_resume(struct device *dev)
{
struct mtk_rng *priv = dev_get_drvdata(dev);
return mtk_rng_init(&priv->rng);
}
static const struct dev_pm_ops mtk_rng_pm_ops = {
SET_RUNTIME_PM_OPS(mtk_rng_runtime_suspend,
mtk_rng_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
};
#define MTK_RNG_PM_OPS (&mtk_rng_pm_ops)
#else /* CONFIG_PM */
#define MTK_RNG_PM_OPS NULL
#endif /* CONFIG_PM */
static const struct of_device_id mtk_rng_match[] = {
{ .compatible = "mediatek,mt7986-rng" },
{ .compatible = "mediatek,mt7623-rng" },
{},
};
MODULE_DEVICE_TABLE(of, mtk_rng_match);
static struct platform_driver mtk_rng_driver = {
.probe = mtk_rng_probe,
.driver = {
.name = MTK_RNG_DEV,
.pm = MTK_RNG_PM_OPS,
.of_match_table = mtk_rng_match,
},
};
module_platform_driver(mtk_rng_driver);
MODULE_DESCRIPTION("Mediatek Random Number Generator Driver");
MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
MODULE_LICENSE("GPL");
|
