Commit | Line | Data |
---|---|---|
35e95e63 OH |
1 | /* |
2 | * c 2001 PPC 64 Team, IBM Corp | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | * | |
9 | * /dev/nvram driver for PPC | |
10 | * | |
11 | */ | |
12 | ||
13 | #include <linux/kernel.h> | |
14 | #include <linux/init.h> | |
35e95e63 | 15 | #include <linux/spinlock.h> |
7c0f6ba6 | 16 | #include <linux/uaccess.h> |
35e95e63 OH |
17 | #include <asm/prom.h> |
18 | #include <asm/machdep.h> | |
39838299 | 19 | #include <asm/rtas.h> |
35e95e63 OH |
20 | #include "chrp.h" |
21 | ||
22 | static unsigned int nvram_size; | |
23 | static unsigned char nvram_buf[4]; | |
24 | static DEFINE_SPINLOCK(nvram_lock); | |
25 | ||
26 | static unsigned char chrp_nvram_read(int addr) | |
27 | { | |
39838299 PM |
28 | unsigned int done; |
29 | unsigned long flags; | |
35e95e63 OH |
30 | unsigned char ret; |
31 | ||
32 | if (addr >= nvram_size) { | |
33 | printk(KERN_DEBUG "%s: read addr %d > nvram_size %u\n", | |
34 | current->comm, addr, nvram_size); | |
35 | return 0xff; | |
36 | } | |
37 | spin_lock_irqsave(&nvram_lock, flags); | |
19fa17e5 PM |
38 | if ((rtas_call(rtas_token("nvram-fetch"), 3, 2, &done, addr, |
39 | __pa(nvram_buf), 1) != 0) || 1 != done) | |
35e95e63 OH |
40 | ret = 0xff; |
41 | else | |
42 | ret = nvram_buf[0]; | |
43 | spin_unlock_irqrestore(&nvram_lock, flags); | |
44 | ||
45 | return ret; | |
46 | } | |
47 | ||
48 | static void chrp_nvram_write(int addr, unsigned char val) | |
49 | { | |
39838299 PM |
50 | unsigned int done; |
51 | unsigned long flags; | |
35e95e63 OH |
52 | |
53 | if (addr >= nvram_size) { | |
54 | printk(KERN_DEBUG "%s: write addr %d > nvram_size %u\n", | |
55 | current->comm, addr, nvram_size); | |
56 | return; | |
57 | } | |
58 | spin_lock_irqsave(&nvram_lock, flags); | |
59 | nvram_buf[0] = val; | |
19fa17e5 PM |
60 | if ((rtas_call(rtas_token("nvram-store"), 3, 2, &done, addr, |
61 | __pa(nvram_buf), 1) != 0) || 1 != done) | |
35e95e63 OH |
62 | printk(KERN_DEBUG "rtas IO error storing 0x%02x at %d", val, addr); |
63 | spin_unlock_irqrestore(&nvram_lock, flags); | |
64 | } | |
65 | ||
66 | void __init chrp_nvram_init(void) | |
67 | { | |
68 | struct device_node *nvram; | |
563c5d8a | 69 | const __be32 *nbytes_p; |
ae6b4101 | 70 | unsigned int proplen; |
35e95e63 OH |
71 | |
72 | nvram = of_find_node_by_type(NULL, "nvram"); | |
73 | if (nvram == NULL) | |
74 | return; | |
75 | ||
e2eb6392 | 76 | nbytes_p = of_get_property(nvram, "#bytes", &proplen); |
7cf9bac5 JL |
77 | if (nbytes_p == NULL || proplen != sizeof(unsigned int)) { |
78 | of_node_put(nvram); | |
35e95e63 | 79 | return; |
7cf9bac5 | 80 | } |
35e95e63 | 81 | |
563c5d8a | 82 | nvram_size = be32_to_cpup(nbytes_p); |
35e95e63 OH |
83 | |
84 | printk(KERN_INFO "CHRP nvram contains %u bytes\n", nvram_size); | |
85 | of_node_put(nvram); | |
86 | ||
87 | ppc_md.nvram_read_val = chrp_nvram_read; | |
88 | ppc_md.nvram_write_val = chrp_nvram_write; | |
89 | ||
90 | return; | |
91 | } |