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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 | ||
f3f66f59 | 56 | static ssize_t mmio_nvram_write(char *buf, size_t count, loff_t *index) |
5f5b4e66 UB |
57 | { |
58 | unsigned long flags; | |
59 | ||
f3f66f59 | 60 | if (*index >= mmio_nvram_len) |
5f5b4e66 | 61 | return 0; |
f3f66f59 AB |
62 | if (*index + count > mmio_nvram_len) |
63 | count = mmio_nvram_len - *index; | |
5f5b4e66 | 64 | |
f3f66f59 | 65 | spin_lock_irqsave(&mmio_nvram_lock, flags); |
5f5b4e66 | 66 | |
f3f66f59 | 67 | memcpy_toio(mmio_nvram_start + *index, buf, count); |
5f5b4e66 | 68 | |
f3f66f59 | 69 | spin_unlock_irqrestore(&mmio_nvram_lock, flags); |
5f5b4e66 UB |
70 | |
71 | *index += count; | |
72 | return count; | |
73 | } | |
74 | ||
f3f66f59 | 75 | static ssize_t mmio_nvram_get_size(void) |
5f5b4e66 | 76 | { |
f3f66f59 | 77 | return mmio_nvram_len; |
5f5b4e66 UB |
78 | } |
79 | ||
f3f66f59 | 80 | int __init mmio_nvram_init(void) |
5f5b4e66 UB |
81 | { |
82 | struct device_node *nvram_node; | |
a7f67bdf | 83 | const unsigned long *buffer; |
5f5b4e66 UB |
84 | int proplen; |
85 | unsigned long nvram_addr; | |
86 | int ret; | |
87 | ||
88 | ret = -ENODEV; | |
89 | nvram_node = of_find_node_by_type(NULL, "nvram"); | |
90 | if (!nvram_node) | |
91 | goto out; | |
92 | ||
93 | ret = -EIO; | |
a7f67bdf | 94 | buffer = get_property(nvram_node, "reg", &proplen); |
5f5b4e66 UB |
95 | if (proplen != 2*sizeof(unsigned long)) |
96 | goto out; | |
97 | ||
98 | ret = -ENODEV; | |
99 | nvram_addr = buffer[0]; | |
f3f66f59 AB |
100 | mmio_nvram_len = buffer[1]; |
101 | if ( (!mmio_nvram_len) || (!nvram_addr) ) | |
5f5b4e66 UB |
102 | goto out; |
103 | ||
f3f66f59 AB |
104 | mmio_nvram_start = ioremap(nvram_addr, mmio_nvram_len); |
105 | if (!mmio_nvram_start) | |
5f5b4e66 UB |
106 | goto out; |
107 | ||
f3f66f59 AB |
108 | printk(KERN_INFO "mmio NVRAM, %luk mapped to %p\n", |
109 | mmio_nvram_len >> 10, mmio_nvram_start); | |
5f5b4e66 | 110 | |
f3f66f59 AB |
111 | ppc_md.nvram_read = mmio_nvram_read; |
112 | ppc_md.nvram_write = mmio_nvram_write; | |
113 | ppc_md.nvram_size = mmio_nvram_get_size; | |
5f5b4e66 UB |
114 | |
115 | out: | |
116 | of_node_put(nvram_node); | |
117 | return ret; | |
118 | } |