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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/*
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_address.h>
28#include <linux/of_platform.h>
29#include <asm/io.h>
30
31#define SDCRNG_CTL_REG 0x00
32#define SDCRNG_CTL_FVLD_M 0x0000f000
33#define SDCRNG_CTL_FVLD_S 12
34#define SDCRNG_CTL_KSZ 0x00000800
35#define SDCRNG_CTL_RSRC_CRG 0x00000010
36#define SDCRNG_CTL_RSRC_RRG 0x00000000
37#define SDCRNG_CTL_CE 0x00000004
38#define SDCRNG_CTL_RE 0x00000002
39#define SDCRNG_CTL_DR 0x00000001
40#define SDCRNG_CTL_SELECT_RRG_RNG (SDCRNG_CTL_RE | SDCRNG_CTL_RSRC_RRG)
41#define SDCRNG_CTL_SELECT_CRG_RNG (SDCRNG_CTL_CE | SDCRNG_CTL_RSRC_CRG)
42#define SDCRNG_VAL_REG 0x20
43
44#define MODULE_NAME "pasemi_rng"
45
46static int pasemi_rng_data_present(struct hwrng *rng, int wait)
47{
48 void __iomem *rng_regs = (void __iomem *)rng->priv;
49 int data, i;
50
51 for (i = 0; i < 20; i++) {
52 data = (in_le32(rng_regs + SDCRNG_CTL_REG)
53 & SDCRNG_CTL_FVLD_M) ? 1 : 0;
54 if (data || !wait)
55 break;
56 udelay(10);
57 }
58 return data;
59}
60
61static int pasemi_rng_data_read(struct hwrng *rng, u32 *data)
62{
63 void __iomem *rng_regs = (void __iomem *)rng->priv;
64 *data = in_le32(rng_regs + SDCRNG_VAL_REG);
65 return 4;
66}
67
68static int pasemi_rng_init(struct hwrng *rng)
69{
70 void __iomem *rng_regs = (void __iomem *)rng->priv;
71 u32 ctl;
72
73 ctl = SDCRNG_CTL_DR | SDCRNG_CTL_SELECT_RRG_RNG | SDCRNG_CTL_KSZ;
74 out_le32(rng_regs + SDCRNG_CTL_REG, ctl);
75 out_le32(rng_regs + SDCRNG_CTL_REG, ctl & ~SDCRNG_CTL_DR);
76
77 return 0;
78}
79
80static void pasemi_rng_cleanup(struct hwrng *rng)
81{
82 void __iomem *rng_regs = (void __iomem *)rng->priv;
83 u32 ctl;
84
85 ctl = SDCRNG_CTL_RE | SDCRNG_CTL_CE;
86 out_le32(rng_regs + SDCRNG_CTL_REG,
87 in_le32(rng_regs + SDCRNG_CTL_REG) & ~ctl);
88}
89
90static struct hwrng pasemi_rng = {
91 .name = MODULE_NAME,
92 .init = pasemi_rng_init,
93 .cleanup = pasemi_rng_cleanup,
94 .data_present = pasemi_rng_data_present,
95 .data_read = pasemi_rng_data_read,
96};
97
98static int rng_probe(struct platform_device *ofdev)
99{
100 void __iomem *rng_regs;
101 struct device_node *rng_np = ofdev->dev.of_node;
102 struct resource res;
103 int err = 0;
104
105 err = of_address_to_resource(rng_np, 0, &res);
106 if (err)
107 return -ENODEV;
108
109 rng_regs = ioremap(res.start, 0x100);
110
111 if (!rng_regs)
112 return -ENOMEM;
113
114 pasemi_rng.priv = (unsigned long)rng_regs;
115
116 printk(KERN_INFO "Registering PA Semi RNG\n");
117
118 err = hwrng_register(&pasemi_rng);
119
120 if (err)
121 iounmap(rng_regs);
122
123 return err;
124}
125
126static int rng_remove(struct platform_device *dev)
127{
128 void __iomem *rng_regs = (void __iomem *)pasemi_rng.priv;
129
130 hwrng_unregister(&pasemi_rng);
131 iounmap(rng_regs);
132
133 return 0;
134}
135
136static struct of_device_id rng_match[] = {
137 { .compatible = "1682m-rng", },
138 { .compatible = "pasemi,pwrficient-rng", },
139 { },
140};
141
142static struct platform_driver rng_driver = {
143 .driver = {
144 .name = "pasemi-rng",
145 .owner = THIS_MODULE,
146 .of_match_table = rng_match,
147 },
148 .probe = rng_probe,
149 .remove = rng_remove,
150};
151
152module_platform_driver(rng_driver);
153
154MODULE_LICENSE("GPL");
155MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>");
156MODULE_DESCRIPTION("H/W RNG driver for PA Semi processor");