Loading...
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/mod_devicetable.h>
13#include <linux/platform_device.h>
14#include <linux/hw_random.h>
15#include <linux/delay.h>
16#include <linux/io.h>
17
18#define SDCRNG_CTL_REG 0x00
19#define SDCRNG_CTL_FVLD_M 0x0000f000
20#define SDCRNG_CTL_FVLD_S 12
21#define SDCRNG_CTL_KSZ 0x00000800
22#define SDCRNG_CTL_RSRC_CRG 0x00000010
23#define SDCRNG_CTL_RSRC_RRG 0x00000000
24#define SDCRNG_CTL_CE 0x00000004
25#define SDCRNG_CTL_RE 0x00000002
26#define SDCRNG_CTL_DR 0x00000001
27#define SDCRNG_CTL_SELECT_RRG_RNG (SDCRNG_CTL_RE | SDCRNG_CTL_RSRC_RRG)
28#define SDCRNG_CTL_SELECT_CRG_RNG (SDCRNG_CTL_CE | SDCRNG_CTL_RSRC_CRG)
29#define SDCRNG_VAL_REG 0x20
30
31#define MODULE_NAME "pasemi_rng"
32
33static int pasemi_rng_data_present(struct hwrng *rng, int wait)
34{
35 void __iomem *rng_regs = (void __iomem *)rng->priv;
36 int data, i;
37
38 for (i = 0; i < 20; i++) {
39 data = (in_le32(rng_regs + SDCRNG_CTL_REG)
40 & SDCRNG_CTL_FVLD_M) ? 1 : 0;
41 if (data || !wait)
42 break;
43 udelay(10);
44 }
45 return data;
46}
47
48static int pasemi_rng_data_read(struct hwrng *rng, u32 *data)
49{
50 void __iomem *rng_regs = (void __iomem *)rng->priv;
51 *data = in_le32(rng_regs + SDCRNG_VAL_REG);
52 return 4;
53}
54
55static int pasemi_rng_init(struct hwrng *rng)
56{
57 void __iomem *rng_regs = (void __iomem *)rng->priv;
58 u32 ctl;
59
60 ctl = SDCRNG_CTL_DR | SDCRNG_CTL_SELECT_RRG_RNG | SDCRNG_CTL_KSZ;
61 out_le32(rng_regs + SDCRNG_CTL_REG, ctl);
62 out_le32(rng_regs + SDCRNG_CTL_REG, ctl & ~SDCRNG_CTL_DR);
63
64 return 0;
65}
66
67static void pasemi_rng_cleanup(struct hwrng *rng)
68{
69 void __iomem *rng_regs = (void __iomem *)rng->priv;
70 u32 ctl;
71
72 ctl = SDCRNG_CTL_RE | SDCRNG_CTL_CE;
73 out_le32(rng_regs + SDCRNG_CTL_REG,
74 in_le32(rng_regs + SDCRNG_CTL_REG) & ~ctl);
75}
76
77static struct hwrng pasemi_rng = {
78 .name = MODULE_NAME,
79 .init = pasemi_rng_init,
80 .cleanup = pasemi_rng_cleanup,
81 .data_present = pasemi_rng_data_present,
82 .data_read = pasemi_rng_data_read,
83};
84
85static int rng_probe(struct platform_device *pdev)
86{
87 void __iomem *rng_regs;
88
89 rng_regs = devm_platform_ioremap_resource(pdev, 0);
90 if (IS_ERR(rng_regs))
91 return PTR_ERR(rng_regs);
92
93 pasemi_rng.priv = (unsigned long)rng_regs;
94
95 pr_info("Registering PA Semi RNG\n");
96 return devm_hwrng_register(&pdev->dev, &pasemi_rng);
97}
98
99static const struct of_device_id rng_match[] = {
100 { .compatible = "1682m-rng", },
101 { .compatible = "pasemi,pwrficient-rng", },
102 { },
103};
104MODULE_DEVICE_TABLE(of, rng_match);
105
106static struct platform_driver rng_driver = {
107 .driver = {
108 .name = "pasemi-rng",
109 .of_match_table = rng_match,
110 },
111 .probe = rng_probe,
112};
113
114module_platform_driver(rng_driver);
115
116MODULE_LICENSE("GPL");
117MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>");
118MODULE_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 pr_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 const struct of_device_id rng_match[] = {
137 { .compatible = "1682m-rng", },
138 { .compatible = "pasemi,pwrficient-rng", },
139 { },
140};
141MODULE_DEVICE_TABLE(of, rng_match);
142
143static struct platform_driver rng_driver = {
144 .driver = {
145 .name = "pasemi-rng",
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");