diff options
Diffstat (limited to 'arch/ppc64/kernel/bpa_nvram.c')
-rw-r--r-- | arch/ppc64/kernel/bpa_nvram.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/bpa_nvram.c b/arch/ppc64/kernel/bpa_nvram.c new file mode 100644 index 000000000000..06a119cfceb5 --- /dev/null +++ b/arch/ppc64/kernel/bpa_nvram.c | |||
@@ -0,0 +1,118 @@ | |||
1 | /* | ||
2 | * NVRAM for CPBW | ||
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 | |||
33 | static void __iomem *bpa_nvram_start; | ||
34 | static long bpa_nvram_len; | ||
35 | static spinlock_t bpa_nvram_lock = SPIN_LOCK_UNLOCKED; | ||
36 | |||
37 | static ssize_t bpa_nvram_read(char *buf, size_t count, loff_t *index) | ||
38 | { | ||
39 | unsigned long flags; | ||
40 | |||
41 | if (*index >= bpa_nvram_len) | ||
42 | return 0; | ||
43 | if (*index + count > bpa_nvram_len) | ||
44 | count = bpa_nvram_len - *index; | ||
45 | |||
46 | spin_lock_irqsave(&bpa_nvram_lock, flags); | ||
47 | |||
48 | memcpy_fromio(buf, bpa_nvram_start + *index, count); | ||
49 | |||
50 | spin_unlock_irqrestore(&bpa_nvram_lock, flags); | ||
51 | |||
52 | *index += count; | ||
53 | return count; | ||
54 | } | ||
55 | |||
56 | static ssize_t bpa_nvram_write(char *buf, size_t count, loff_t *index) | ||
57 | { | ||
58 | unsigned long flags; | ||
59 | |||
60 | if (*index >= bpa_nvram_len) | ||
61 | return 0; | ||
62 | if (*index + count > bpa_nvram_len) | ||
63 | count = bpa_nvram_len - *index; | ||
64 | |||
65 | spin_lock_irqsave(&bpa_nvram_lock, flags); | ||
66 | |||
67 | memcpy_toio(bpa_nvram_start + *index, buf, count); | ||
68 | |||
69 | spin_unlock_irqrestore(&bpa_nvram_lock, flags); | ||
70 | |||
71 | *index += count; | ||
72 | return count; | ||
73 | } | ||
74 | |||
75 | static ssize_t bpa_nvram_get_size(void) | ||
76 | { | ||
77 | return bpa_nvram_len; | ||
78 | } | ||
79 | |||
80 | int __init bpa_nvram_init(void) | ||
81 | { | ||
82 | struct device_node *nvram_node; | ||
83 | unsigned long *buffer; | ||
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; | ||
94 | buffer = (unsigned long *)get_property(nvram_node, "reg", &proplen); | ||
95 | if (proplen != 2*sizeof(unsigned long)) | ||
96 | goto out; | ||
97 | |||
98 | ret = -ENODEV; | ||
99 | nvram_addr = buffer[0]; | ||
100 | bpa_nvram_len = buffer[1]; | ||
101 | if ( (!bpa_nvram_len) || (!nvram_addr) ) | ||
102 | goto out; | ||
103 | |||
104 | bpa_nvram_start = ioremap(nvram_addr, bpa_nvram_len); | ||
105 | if (!bpa_nvram_start) | ||
106 | goto out; | ||
107 | |||
108 | printk(KERN_INFO "BPA NVRAM, %luk mapped to %p\n", | ||
109 | bpa_nvram_len >> 10, bpa_nvram_start); | ||
110 | |||
111 | ppc_md.nvram_read = bpa_nvram_read; | ||
112 | ppc_md.nvram_write = bpa_nvram_write; | ||
113 | ppc_md.nvram_size = bpa_nvram_get_size; | ||
114 | |||
115 | out: | ||
116 | of_node_put(nvram_node); | ||
117 | return ret; | ||
118 | } | ||