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e123be16 NA |
1 | /* |
2 | * This file is provided under a dual BSD/GPLv2 license. When using or | |
3 | * redistributing this file, you may do so under either license. | |
4 | * | |
5 | * GPL LICENSE SUMMARY | |
6 | * | |
7 | * Copyright (c) 2016 BayLibre, SAS. | |
8 | * Author: Neil Armstrong <narmstrong@baylibre.com> | |
9 | * Copyright (C) 2014 Amlogic, Inc. | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of version 2 of the GNU General Public License as | |
13 | * published by the Free Software Foundation. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, but | |
16 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
22 | * The full GNU General Public License is included in this distribution | |
23 | * in the file called COPYING. | |
24 | * | |
25 | * BSD LICENSE | |
26 | * | |
27 | * Copyright (c) 2016 BayLibre, SAS. | |
28 | * Author: Neil Armstrong <narmstrong@baylibre.com> | |
29 | * Copyright (C) 2014 Amlogic, Inc. | |
30 | * | |
31 | * Redistribution and use in source and binary forms, with or without | |
32 | * modification, are permitted provided that the following conditions | |
33 | * are met: | |
34 | * | |
35 | * * Redistributions of source code must retain the above copyright | |
36 | * notice, this list of conditions and the following disclaimer. | |
37 | * * Redistributions in binary form must reproduce the above copyright | |
38 | * notice, this list of conditions and the following disclaimer in | |
39 | * the documentation and/or other materials provided with the | |
40 | * distribution. | |
41 | * * Neither the name of Intel Corporation nor the names of its | |
42 | * contributors may be used to endorse or promote products derived | |
43 | * from this software without specific prior written permission. | |
44 | * | |
45 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
46 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
47 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
48 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
49 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
50 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
51 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
52 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
53 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
54 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
55 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
56 | */ | |
57 | #include <linux/err.h> | |
58 | #include <linux/module.h> | |
59 | #include <linux/io.h> | |
60 | #include <linux/platform_device.h> | |
61 | #include <linux/hw_random.h> | |
62 | #include <linux/slab.h> | |
63 | #include <linux/types.h> | |
64 | #include <linux/of.h> | |
65 | ||
66 | #define RNG_DATA 0x00 | |
67 | ||
68 | struct meson_rng_data { | |
69 | void __iomem *base; | |
70 | struct platform_device *pdev; | |
71 | struct hwrng rng; | |
72 | }; | |
73 | ||
74 | static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) | |
75 | { | |
76 | struct meson_rng_data *data = | |
77 | container_of(rng, struct meson_rng_data, rng); | |
78 | ||
e123be16 NA |
79 | *(u32 *)buf = readl_relaxed(data->base + RNG_DATA); |
80 | ||
81 | return sizeof(u32); | |
82 | } | |
83 | ||
84 | static int meson_rng_probe(struct platform_device *pdev) | |
85 | { | |
86 | struct device *dev = &pdev->dev; | |
87 | struct meson_rng_data *data; | |
88 | struct resource *res; | |
89 | ||
90 | data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); | |
91 | if (!data) | |
92 | return -ENOMEM; | |
93 | ||
94 | data->pdev = pdev; | |
95 | ||
96 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
97 | data->base = devm_ioremap_resource(dev, res); | |
98 | if (IS_ERR(data->base)) | |
99 | return PTR_ERR(data->base); | |
100 | ||
101 | data->rng.name = pdev->name; | |
102 | data->rng.read = meson_rng_read; | |
103 | ||
104 | platform_set_drvdata(pdev, data); | |
105 | ||
106 | return devm_hwrng_register(dev, &data->rng); | |
107 | } | |
108 | ||
109 | static const struct of_device_id meson_rng_of_match[] = { | |
110 | { .compatible = "amlogic,meson-rng", }, | |
111 | {}, | |
112 | }; | |
113 | ||
114 | static struct platform_driver meson_rng_driver = { | |
115 | .probe = meson_rng_probe, | |
116 | .driver = { | |
117 | .name = "meson-rng", | |
118 | .of_match_table = meson_rng_of_match, | |
119 | }, | |
120 | }; | |
121 | ||
122 | module_platform_driver(meson_rng_driver); | |
123 | ||
124 | MODULE_ALIAS("platform:meson-rng"); | |
125 | MODULE_DESCRIPTION("Meson H/W Random Number Generator driver"); | |
126 | MODULE_AUTHOR("Lawrence Mok <lawrence.mok@amlogic.com>"); | |
127 | MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>"); | |
128 | MODULE_LICENSE("Dual BSD/GPL"); |