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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * memory mapped NVRAM
4 *
5 * (C) Copyright IBM Corp. 2005
6 *
7 * Authors : Utz Bacher <utz.bacher@de.ibm.com>
8 */
9
10#include <linux/fs.h>
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/of_address.h>
14#include <linux/spinlock.h>
15#include <linux/types.h>
16
17#include <asm/machdep.h>
18#include <asm/nvram.h>
19
20static void __iomem *mmio_nvram_start;
21static long mmio_nvram_len;
22static DEFINE_SPINLOCK(mmio_nvram_lock);
23
24static ssize_t mmio_nvram_read(char *buf, size_t count, loff_t *index)
25{
26 unsigned long flags;
27
28 if (*index >= mmio_nvram_len)
29 return 0;
30 if (*index + count > mmio_nvram_len)
31 count = mmio_nvram_len - *index;
32
33 spin_lock_irqsave(&mmio_nvram_lock, flags);
34
35 memcpy_fromio(buf, mmio_nvram_start + *index, count);
36
37 spin_unlock_irqrestore(&mmio_nvram_lock, flags);
38
39 *index += count;
40 return count;
41}
42
43static unsigned char mmio_nvram_read_val(int addr)
44{
45 unsigned long flags;
46 unsigned char val;
47
48 if (addr >= mmio_nvram_len)
49 return 0xff;
50
51 spin_lock_irqsave(&mmio_nvram_lock, flags);
52
53 val = ioread8(mmio_nvram_start + addr);
54
55 spin_unlock_irqrestore(&mmio_nvram_lock, flags);
56
57 return val;
58}
59
60static ssize_t mmio_nvram_write(char *buf, size_t count, loff_t *index)
61{
62 unsigned long flags;
63
64 if (*index >= mmio_nvram_len)
65 return 0;
66 if (*index + count > mmio_nvram_len)
67 count = mmio_nvram_len - *index;
68
69 spin_lock_irqsave(&mmio_nvram_lock, flags);
70
71 memcpy_toio(mmio_nvram_start + *index, buf, count);
72
73 spin_unlock_irqrestore(&mmio_nvram_lock, flags);
74
75 *index += count;
76 return count;
77}
78
79static void mmio_nvram_write_val(int addr, unsigned char val)
80{
81 unsigned long flags;
82
83 if (addr < mmio_nvram_len) {
84 spin_lock_irqsave(&mmio_nvram_lock, flags);
85
86 iowrite8(val, mmio_nvram_start + addr);
87
88 spin_unlock_irqrestore(&mmio_nvram_lock, flags);
89 }
90}
91
92static ssize_t mmio_nvram_get_size(void)
93{
94 return mmio_nvram_len;
95}
96
97int __init mmio_nvram_init(void)
98{
99 struct device_node *nvram_node;
100 unsigned long nvram_addr;
101 struct resource r;
102 int ret;
103
104 nvram_node = of_find_node_by_type(NULL, "nvram");
105 if (!nvram_node)
106 nvram_node = of_find_compatible_node(NULL, NULL, "nvram");
107 if (!nvram_node) {
108 printk(KERN_WARNING "nvram: no node found in device-tree\n");
109 return -ENODEV;
110 }
111
112 ret = of_address_to_resource(nvram_node, 0, &r);
113 if (ret) {
114 printk(KERN_WARNING "nvram: failed to get address (err %d)\n",
115 ret);
116 goto out;
117 }
118 nvram_addr = r.start;
119 mmio_nvram_len = resource_size(&r);
120 if ( (!mmio_nvram_len) || (!nvram_addr) ) {
121 printk(KERN_WARNING "nvram: address or length is 0\n");
122 ret = -EIO;
123 goto out;
124 }
125
126 mmio_nvram_start = ioremap(nvram_addr, mmio_nvram_len);
127 if (!mmio_nvram_start) {
128 printk(KERN_WARNING "nvram: failed to ioremap\n");
129 ret = -ENOMEM;
130 goto out;
131 }
132
133 printk(KERN_INFO "mmio NVRAM, %luk at 0x%lx mapped to %p\n",
134 mmio_nvram_len >> 10, nvram_addr, mmio_nvram_start);
135
136 ppc_md.nvram_read_val = mmio_nvram_read_val;
137 ppc_md.nvram_write_val = mmio_nvram_write_val;
138 ppc_md.nvram_read = mmio_nvram_read;
139 ppc_md.nvram_write = mmio_nvram_write;
140 ppc_md.nvram_size = mmio_nvram_get_size;
141
142out:
143 of_node_put(nvram_node);
144 return ret;
145}
1/*
2 * memory mapped NVRAM
3 *
4 * (C) Copyright IBM Corp. 2005
5 *
6 * Authors : Utz Bacher <utz.bacher@de.ibm.com>
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 as published by
10 * the Free Software Foundation; either version 2, or (at your option)
11 * any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22
23#include <linux/fs.h>
24#include <linux/init.h>
25#include <linux/kernel.h>
26#include <linux/spinlock.h>
27#include <linux/types.h>
28
29#include <asm/machdep.h>
30#include <asm/nvram.h>
31#include <asm/prom.h>
32
33static void __iomem *mmio_nvram_start;
34static long mmio_nvram_len;
35static DEFINE_SPINLOCK(mmio_nvram_lock);
36
37static ssize_t mmio_nvram_read(char *buf, size_t count, loff_t *index)
38{
39 unsigned long flags;
40
41 if (*index >= mmio_nvram_len)
42 return 0;
43 if (*index + count > mmio_nvram_len)
44 count = mmio_nvram_len - *index;
45
46 spin_lock_irqsave(&mmio_nvram_lock, flags);
47
48 memcpy_fromio(buf, mmio_nvram_start + *index, count);
49
50 spin_unlock_irqrestore(&mmio_nvram_lock, flags);
51
52 *index += count;
53 return count;
54}
55
56static unsigned char mmio_nvram_read_val(int addr)
57{
58 unsigned long flags;
59 unsigned char val;
60
61 if (addr >= mmio_nvram_len)
62 return 0xff;
63
64 spin_lock_irqsave(&mmio_nvram_lock, flags);
65
66 val = ioread8(mmio_nvram_start + addr);
67
68 spin_unlock_irqrestore(&mmio_nvram_lock, flags);
69
70 return val;
71}
72
73static ssize_t mmio_nvram_write(char *buf, size_t count, loff_t *index)
74{
75 unsigned long flags;
76
77 if (*index >= mmio_nvram_len)
78 return 0;
79 if (*index + count > mmio_nvram_len)
80 count = mmio_nvram_len - *index;
81
82 spin_lock_irqsave(&mmio_nvram_lock, flags);
83
84 memcpy_toio(mmio_nvram_start + *index, buf, count);
85
86 spin_unlock_irqrestore(&mmio_nvram_lock, flags);
87
88 *index += count;
89 return count;
90}
91
92void mmio_nvram_write_val(int addr, unsigned char val)
93{
94 unsigned long flags;
95
96 if (addr < mmio_nvram_len) {
97 spin_lock_irqsave(&mmio_nvram_lock, flags);
98
99 iowrite8(val, mmio_nvram_start + addr);
100
101 spin_unlock_irqrestore(&mmio_nvram_lock, flags);
102 }
103}
104
105static ssize_t mmio_nvram_get_size(void)
106{
107 return mmio_nvram_len;
108}
109
110int __init mmio_nvram_init(void)
111{
112 struct device_node *nvram_node;
113 unsigned long nvram_addr;
114 struct resource r;
115 int ret;
116
117 nvram_node = of_find_node_by_type(NULL, "nvram");
118 if (!nvram_node)
119 nvram_node = of_find_compatible_node(NULL, NULL, "nvram");
120 if (!nvram_node) {
121 printk(KERN_WARNING "nvram: no node found in device-tree\n");
122 return -ENODEV;
123 }
124
125 ret = of_address_to_resource(nvram_node, 0, &r);
126 if (ret) {
127 printk(KERN_WARNING "nvram: failed to get address (err %d)\n",
128 ret);
129 goto out;
130 }
131 nvram_addr = r.start;
132 mmio_nvram_len = resource_size(&r);
133 if ( (!mmio_nvram_len) || (!nvram_addr) ) {
134 printk(KERN_WARNING "nvram: address or length is 0\n");
135 ret = -EIO;
136 goto out;
137 }
138
139 mmio_nvram_start = ioremap(nvram_addr, mmio_nvram_len);
140 if (!mmio_nvram_start) {
141 printk(KERN_WARNING "nvram: failed to ioremap\n");
142 ret = -ENOMEM;
143 goto out;
144 }
145
146 printk(KERN_INFO "mmio NVRAM, %luk at 0x%lx mapped to %p\n",
147 mmio_nvram_len >> 10, nvram_addr, mmio_nvram_start);
148
149 ppc_md.nvram_read_val = mmio_nvram_read_val;
150 ppc_md.nvram_write_val = mmio_nvram_write_val;
151 ppc_md.nvram_read = mmio_nvram_read;
152 ppc_md.nvram_write = mmio_nvram_write;
153 ppc_md.nvram_size = mmio_nvram_get_size;
154
155out:
156 of_node_put(nvram_node);
157 return ret;
158}