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-rw-r--r--arch/ppc/platforms/chrp_nvram.c83
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
21static unsigned int nvram_size;
22static unsigned char nvram_buf[4];
23static DEFINE_SPINLOCK(nvram_lock);
24
25static 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
45static 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
61void __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}