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1/*
2 * Copyright (C) 2006-2007 PA Semi, Inc
3 *
4 * Maintained by: Olof Johansson <olof@lixom.net>
5 *
6 * Driver for the PWRficient onchip rng
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/module.h>
23#include <linux/kernel.h>
24#include <linux/platform_device.h>
25#include <linux/hw_random.h>
26#include <linux/delay.h>
27#include <linux/of_platform.h>
28#include <asm/io.h>
29
30#define SDCRNG_CTL_REG 0x00
31#define SDCRNG_CTL_FVLD_M 0x0000f000
32#define SDCRNG_CTL_FVLD_S 12
33#define SDCRNG_CTL_KSZ 0x00000800
34#define SDCRNG_CTL_RSRC_CRG 0x00000010
35#define SDCRNG_CTL_RSRC_RRG 0x00000000
36#define SDCRNG_CTL_CE 0x00000004
37#define SDCRNG_CTL_RE 0x00000002
38#define SDCRNG_CTL_DR 0x00000001
39#define SDCRNG_CTL_SELECT_RRG_RNG (SDCRNG_CTL_RE | SDCRNG_CTL_RSRC_RRG)
40#define SDCRNG_CTL_SELECT_CRG_RNG (SDCRNG_CTL_CE | SDCRNG_CTL_RSRC_CRG)
41#define SDCRNG_VAL_REG 0x20
42
43#define MODULE_NAME "pasemi_rng"
44
45static int pasemi_rng_data_present(struct hwrng *rng, int wait)
46{
47 void __iomem *rng_regs = (void __iomem *)rng->priv;
48 int data, i;
49
50 for (i = 0; i < 20; i++) {
51 data = (in_le32(rng_regs + SDCRNG_CTL_REG)
52 & SDCRNG_CTL_FVLD_M) ? 1 : 0;
53 if (data || !wait)
54 break;
55 udelay(10);
56 }
57 return data;
58}
59
60static int pasemi_rng_data_read(struct hwrng *rng, u32 *data)
61{
62 void __iomem *rng_regs = (void __iomem *)rng->priv;
63 *data = in_le32(rng_regs + SDCRNG_VAL_REG);
64 return 4;
65}
66
67static int pasemi_rng_init(struct hwrng *rng)
68{
69 void __iomem *rng_regs = (void __iomem *)rng->priv;
70 u32 ctl;
71
72 ctl = SDCRNG_CTL_DR | SDCRNG_CTL_SELECT_RRG_RNG | SDCRNG_CTL_KSZ;
73 out_le32(rng_regs + SDCRNG_CTL_REG, ctl);
74 out_le32(rng_regs + SDCRNG_CTL_REG, ctl & ~SDCRNG_CTL_DR);
75
76 return 0;
77}
78
79static void pasemi_rng_cleanup(struct hwrng *rng)
80{
81 void __iomem *rng_regs = (void __iomem *)rng->priv;
82 u32 ctl;
83
84 ctl = SDCRNG_CTL_RE | SDCRNG_CTL_CE;
85 out_le32(rng_regs + SDCRNG_CTL_REG,
86 in_le32(rng_regs + SDCRNG_CTL_REG) & ~ctl);
87}
88
89static struct hwrng pasemi_rng = {
90 .name = MODULE_NAME,
91 .init = pasemi_rng_init,
92 .cleanup = pasemi_rng_cleanup,
93 .data_present = pasemi_rng_data_present,
94 .data_read = pasemi_rng_data_read,
95};
96
97static int __devinit rng_probe(struct platform_device *ofdev)
98{
99 void __iomem *rng_regs;
100 struct device_node *rng_np = ofdev->dev.of_node;
101 struct resource res;
102 int err = 0;
103
104 err = of_address_to_resource(rng_np, 0, &res);
105 if (err)
106 return -ENODEV;
107
108 rng_regs = ioremap(res.start, 0x100);
109
110 if (!rng_regs)
111 return -ENOMEM;
112
113 pasemi_rng.priv = (unsigned long)rng_regs;
114
115 printk(KERN_INFO "Registering PA Semi RNG\n");
116
117 err = hwrng_register(&pasemi_rng);
118
119 if (err)
120 iounmap(rng_regs);
121
122 return err;
123}
124
125static int __devexit rng_remove(struct platform_device *dev)
126{
127 void __iomem *rng_regs = (void __iomem *)pasemi_rng.priv;
128
129 hwrng_unregister(&pasemi_rng);
130 iounmap(rng_regs);
131
132 return 0;
133}
134
135static struct of_device_id rng_match[] = {
136 { .compatible = "1682m-rng", },
137 { .compatible = "pasemi,pwrficient-rng", },
138 { },
139};
140
141static struct platform_driver rng_driver = {
142 .driver = {
143 .name = "pasemi-rng",
144 .owner = THIS_MODULE,
145 .of_match_table = rng_match,
146 },
147 .probe = rng_probe,
148 .remove = rng_remove,
149};
150
151static int __init rng_init(void)
152{
153 return platform_driver_register(&rng_driver);
154}
155module_init(rng_init);
156
157static void __exit rng_exit(void)
158{
159 platform_driver_unregister(&rng_driver);
160}
161module_exit(rng_exit);
162
163MODULE_LICENSE("GPL");
164MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>");
165MODULE_DESCRIPTION("H/W RNG driver for PA Semi processor");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2006-2007 PA Semi, Inc
4 *
5 * Maintained by: Olof Johansson <olof@lixom.net>
6 *
7 * Driver for the PWRficient onchip rng
8 */
9
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/platform_device.h>
13#include <linux/hw_random.h>
14#include <linux/delay.h>
15#include <linux/of_address.h>
16#include <linux/of_platform.h>
17#include <linux/io.h>
18
19#define SDCRNG_CTL_REG 0x00
20#define SDCRNG_CTL_FVLD_M 0x0000f000
21#define SDCRNG_CTL_FVLD_S 12
22#define SDCRNG_CTL_KSZ 0x00000800
23#define SDCRNG_CTL_RSRC_CRG 0x00000010
24#define SDCRNG_CTL_RSRC_RRG 0x00000000
25#define SDCRNG_CTL_CE 0x00000004
26#define SDCRNG_CTL_RE 0x00000002
27#define SDCRNG_CTL_DR 0x00000001
28#define SDCRNG_CTL_SELECT_RRG_RNG (SDCRNG_CTL_RE | SDCRNG_CTL_RSRC_RRG)
29#define SDCRNG_CTL_SELECT_CRG_RNG (SDCRNG_CTL_CE | SDCRNG_CTL_RSRC_CRG)
30#define SDCRNG_VAL_REG 0x20
31
32#define MODULE_NAME "pasemi_rng"
33
34static int pasemi_rng_data_present(struct hwrng *rng, int wait)
35{
36 void __iomem *rng_regs = (void __iomem *)rng->priv;
37 int data, i;
38
39 for (i = 0; i < 20; i++) {
40 data = (in_le32(rng_regs + SDCRNG_CTL_REG)
41 & SDCRNG_CTL_FVLD_M) ? 1 : 0;
42 if (data || !wait)
43 break;
44 udelay(10);
45 }
46 return data;
47}
48
49static int pasemi_rng_data_read(struct hwrng *rng, u32 *data)
50{
51 void __iomem *rng_regs = (void __iomem *)rng->priv;
52 *data = in_le32(rng_regs + SDCRNG_VAL_REG);
53 return 4;
54}
55
56static int pasemi_rng_init(struct hwrng *rng)
57{
58 void __iomem *rng_regs = (void __iomem *)rng->priv;
59 u32 ctl;
60
61 ctl = SDCRNG_CTL_DR | SDCRNG_CTL_SELECT_RRG_RNG | SDCRNG_CTL_KSZ;
62 out_le32(rng_regs + SDCRNG_CTL_REG, ctl);
63 out_le32(rng_regs + SDCRNG_CTL_REG, ctl & ~SDCRNG_CTL_DR);
64
65 return 0;
66}
67
68static void pasemi_rng_cleanup(struct hwrng *rng)
69{
70 void __iomem *rng_regs = (void __iomem *)rng->priv;
71 u32 ctl;
72
73 ctl = SDCRNG_CTL_RE | SDCRNG_CTL_CE;
74 out_le32(rng_regs + SDCRNG_CTL_REG,
75 in_le32(rng_regs + SDCRNG_CTL_REG) & ~ctl);
76}
77
78static struct hwrng pasemi_rng = {
79 .name = MODULE_NAME,
80 .init = pasemi_rng_init,
81 .cleanup = pasemi_rng_cleanup,
82 .data_present = pasemi_rng_data_present,
83 .data_read = pasemi_rng_data_read,
84};
85
86static int rng_probe(struct platform_device *pdev)
87{
88 void __iomem *rng_regs;
89
90 rng_regs = devm_platform_ioremap_resource(pdev, 0);
91 if (IS_ERR(rng_regs))
92 return PTR_ERR(rng_regs);
93
94 pasemi_rng.priv = (unsigned long)rng_regs;
95
96 pr_info("Registering PA Semi RNG\n");
97 return devm_hwrng_register(&pdev->dev, &pasemi_rng);
98}
99
100static const struct of_device_id rng_match[] = {
101 { .compatible = "1682m-rng", },
102 { .compatible = "pasemi,pwrficient-rng", },
103 { },
104};
105MODULE_DEVICE_TABLE(of, rng_match);
106
107static struct platform_driver rng_driver = {
108 .driver = {
109 .name = "pasemi-rng",
110 .of_match_table = rng_match,
111 },
112 .probe = rng_probe,
113};
114
115module_platform_driver(rng_driver);
116
117MODULE_LICENSE("GPL");
118MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>");
119MODULE_DESCRIPTION("H/W RNG driver for PA Semi processor");