diff options
Diffstat (limited to 'arch/ppc/platforms/chrp_nvram.c')
-rw-r--r-- | arch/ppc/platforms/chrp_nvram.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/ppc/platforms/chrp_nvram.c b/arch/ppc/platforms/chrp_nvram.c new file mode 100644 index 000000000000..465ba9b090ef --- /dev/null +++ b/arch/ppc/platforms/chrp_nvram.c | |||
@@ -0,0 +1,83 @@ | |||
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> | ||
15 | #include <linux/slab.h> | ||
16 | #include <linux/spinlock.h> | ||
17 | #include <asm/uaccess.h> | ||
18 | #include <asm/prom.h> | ||
19 | #include <asm/machdep.h> | ||
20 | |||
21 | static unsigned int nvram_size; | ||
22 | static unsigned char nvram_buf[4]; | ||
23 | static DEFINE_SPINLOCK(nvram_lock); | ||
24 | |||
25 | static unsigned char chrp_nvram_read(int addr) | ||
26 | { | ||
27 | unsigned long done, flags; | ||
28 | unsigned char ret; | ||
29 | |||
30 | if (addr >= nvram_size) { | ||
31 | printk(KERN_DEBUG "%s: read addr %d > nvram_size %u\n", | ||
32 | current->comm, addr, nvram_size); | ||
33 | return 0xff; | ||
34 | } | ||
35 | spin_lock_irqsave(&nvram_lock, flags); | ||
36 | if ((call_rtas("nvram-fetch", 3, 2, &done, addr, __pa(nvram_buf), 1) != 0) || 1 != done) | ||
37 | ret = 0xff; | ||
38 | else | ||
39 | ret = nvram_buf[0]; | ||
40 | spin_unlock_irqrestore(&nvram_lock, flags); | ||
41 | |||
42 | return ret; | ||
43 | } | ||
44 | |||
45 | static void chrp_nvram_write(int addr, unsigned char val) | ||
46 | { | ||
47 | unsigned long done, flags; | ||
48 | |||
49 | if (addr >= nvram_size) { | ||
50 | printk(KERN_DEBUG "%s: write addr %d > nvram_size %u\n", | ||
51 | current->comm, addr, nvram_size); | ||
52 | return; | ||
53 | } | ||
54 | spin_lock_irqsave(&nvram_lock, flags); | ||
55 | nvram_buf[0] = val; | ||
56 | if ((call_rtas("nvram-store", 3, 2, &done, addr, __pa(nvram_buf), 1) != 0) || 1 != done) | ||
57 | printk(KERN_DEBUG "rtas IO error storing 0x%02x at %d", val, addr); | ||
58 | spin_unlock_irqrestore(&nvram_lock, flags); | ||
59 | } | ||
60 | |||
61 | void __init chrp_nvram_init(void) | ||
62 | { | ||
63 | struct device_node *nvram; | ||
64 | unsigned int *nbytes_p, proplen; | ||
65 | |||
66 | nvram = of_find_node_by_type(NULL, "nvram"); | ||
67 | if (nvram == NULL) | ||
68 | return; | ||
69 | |||
70 | nbytes_p = (unsigned int *)get_property(nvram, "#bytes", &proplen); | ||
71 | if (nbytes_p == NULL || proplen != sizeof(unsigned int)) | ||
72 | return; | ||
73 | |||
74 | nvram_size = *nbytes_p; | ||
75 | |||
76 | printk(KERN_INFO "CHRP nvram contains %u bytes\n", nvram_size); | ||
77 | of_node_put(nvram); | ||
78 | |||
79 | ppc_md.nvram_read_val = chrp_nvram_read; | ||
80 | ppc_md.nvram_write_val = chrp_nvram_write; | ||
81 | |||
82 | return; | ||
83 | } | ||