Commit | Line | Data |
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5f5b4e66 | 1 | /* |
f3f66f59 | 2 | * memory mapped NVRAM |
5f5b4e66 UB |
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 | ||
f3f66f59 AB |
33 | static void __iomem *mmio_nvram_start; |
34 | static long mmio_nvram_len; | |
34af946a | 35 | static DEFINE_SPINLOCK(mmio_nvram_lock); |
5f5b4e66 | 36 | |
f3f66f59 | 37 | static ssize_t mmio_nvram_read(char *buf, size_t count, loff_t *index) |
5f5b4e66 UB |
38 | { |
39 | unsigned long flags; | |
40 | ||
f3f66f59 | 41 | if (*index >= mmio_nvram_len) |
5f5b4e66 | 42 | return 0; |
f3f66f59 AB |
43 | if (*index + count > mmio_nvram_len) |
44 | count = mmio_nvram_len - *index; | |
5f5b4e66 | 45 | |
f3f66f59 | 46 | spin_lock_irqsave(&mmio_nvram_lock, flags); |
5f5b4e66 | 47 | |
f3f66f59 | 48 | memcpy_fromio(buf, mmio_nvram_start + *index, count); |
5f5b4e66 | 49 | |
f3f66f59 | 50 | spin_unlock_irqrestore(&mmio_nvram_lock, flags); |
5f5b4e66 UB |
51 | |
52 | *index += count; | |
53 | return count; | |
54 | } | |
55 | ||
690a2d07 MW |
56 | static 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 | ||
f3f66f59 | 73 | static ssize_t mmio_nvram_write(char *buf, size_t count, loff_t *index) |
5f5b4e66 UB |
74 | { |
75 | unsigned long flags; | |
76 | ||
f3f66f59 | 77 | if (*index >= mmio_nvram_len) |
5f5b4e66 | 78 | return 0; |
f3f66f59 AB |
79 | if (*index + count > mmio_nvram_len) |
80 | count = mmio_nvram_len - *index; | |
5f5b4e66 | 81 | |
f3f66f59 | 82 | spin_lock_irqsave(&mmio_nvram_lock, flags); |
5f5b4e66 | 83 | |
f3f66f59 | 84 | memcpy_toio(mmio_nvram_start + *index, buf, count); |
5f5b4e66 | 85 | |
f3f66f59 | 86 | spin_unlock_irqrestore(&mmio_nvram_lock, flags); |
5f5b4e66 UB |
87 | |
88 | *index += count; | |
89 | return count; | |
90 | } | |
91 | ||
690a2d07 MW |
92 | void 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 | ||
f3f66f59 | 105 | static ssize_t mmio_nvram_get_size(void) |
5f5b4e66 | 106 | { |
f3f66f59 | 107 | return mmio_nvram_len; |
5f5b4e66 UB |
108 | } |
109 | ||
f3f66f59 | 110 | int __init mmio_nvram_init(void) |
5f5b4e66 UB |
111 | { |
112 | struct device_node *nvram_node; | |
5f5b4e66 | 113 | unsigned long nvram_addr; |
6984ee79 | 114 | struct resource r; |
5f5b4e66 UB |
115 | int ret; |
116 | ||
5f5b4e66 | 117 | nvram_node = of_find_node_by_type(NULL, "nvram"); |
411e689d BH |
118 | if (!nvram_node) |
119 | nvram_node = of_find_compatible_node(NULL, NULL, "nvram"); | |
6984ee79 BH |
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); | |
5f5b4e66 | 129 | goto out; |
6984ee79 BH |
130 | } |
131 | nvram_addr = r.start; | |
28f65c11 | 132 | mmio_nvram_len = resource_size(&r); |
6984ee79 | 133 | if ( (!mmio_nvram_len) || (!nvram_addr) ) { |
00d70419 | 134 | printk(KERN_WARNING "nvram: address or length is 0\n"); |
6984ee79 | 135 | ret = -EIO; |
5f5b4e66 | 136 | goto out; |
6984ee79 | 137 | } |
5f5b4e66 | 138 | |
f3f66f59 | 139 | mmio_nvram_start = ioremap(nvram_addr, mmio_nvram_len); |
6984ee79 BH |
140 | if (!mmio_nvram_start) { |
141 | printk(KERN_WARNING "nvram: failed to ioremap\n"); | |
142 | ret = -ENOMEM; | |
5f5b4e66 | 143 | goto out; |
6984ee79 | 144 | } |
5f5b4e66 | 145 | |
6984ee79 BH |
146 | printk(KERN_INFO "mmio NVRAM, %luk at 0x%lx mapped to %p\n", |
147 | mmio_nvram_len >> 10, nvram_addr, mmio_nvram_start); | |
5f5b4e66 | 148 | |
690a2d07 MW |
149 | ppc_md.nvram_read_val = mmio_nvram_read_val; |
150 | ppc_md.nvram_write_val = mmio_nvram_write_val; | |
f3f66f59 AB |
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; | |
5f5b4e66 UB |
154 | |
155 | out: | |
156 | of_node_put(nvram_node); | |
157 | return ret; | |
158 | } |