2 * c 2001 PPC 64 Team, IBM Corp
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.
9 * /dev/nvram driver for PPC64
11 * This perhaps should live in drivers/char
15 #include <linux/types.h>
16 #include <linux/errno.h>
17 #include <linux/init.h>
18 #include <linux/spinlock.h>
19 #include <asm/uaccess.h>
20 #include <asm/nvram.h>
23 #include <asm/machdep.h>
25 static unsigned int nvram_size;
26 static int nvram_fetch, nvram_store;
27 static char nvram_buf[NVRW_CNT]; /* assume this is in the first 4GB */
28 static DEFINE_SPINLOCK(nvram_lock);
31 static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index)
40 if (nvram_size == 0 || nvram_fetch == RTAS_UNKNOWN_SERVICE)
43 if (*index >= nvram_size)
47 if (i + count > nvram_size)
48 count = nvram_size - i;
50 spin_lock_irqsave(&nvram_lock, flags);
52 for (; count != 0; count -= len) {
57 if ((rtas_call(nvram_fetch, 3, 2, &done, i, __pa(nvram_buf),
58 len) != 0) || len != done) {
59 spin_unlock_irqrestore(&nvram_lock, flags);
63 memcpy(p, nvram_buf, len);
69 spin_unlock_irqrestore(&nvram_lock, flags);
75 static ssize_t pSeries_nvram_write(char *buf, size_t count, loff_t *index)
83 if (nvram_size == 0 || nvram_store == RTAS_UNKNOWN_SERVICE)
86 if (*index >= nvram_size)
90 if (i + count > nvram_size)
91 count = nvram_size - i;
93 spin_lock_irqsave(&nvram_lock, flags);
95 for (; count != 0; count -= len) {
100 memcpy(nvram_buf, p, len);
102 if ((rtas_call(nvram_store, 3, 2, &done, i, __pa(nvram_buf),
103 len) != 0) || len != done) {
104 spin_unlock_irqrestore(&nvram_lock, flags);
111 spin_unlock_irqrestore(&nvram_lock, flags);
117 static ssize_t pSeries_nvram_get_size(void)
119 return nvram_size ? nvram_size : -ENODEV;
122 int __init pSeries_nvram_init(void)
124 struct device_node *nvram;
125 const unsigned int *nbytes_p;
126 unsigned int proplen;
128 nvram = of_find_node_by_type(NULL, "nvram");
132 nbytes_p = of_get_property(nvram, "#bytes", &proplen);
133 if (nbytes_p == NULL || proplen != sizeof(unsigned int)) {
138 nvram_size = *nbytes_p;
140 nvram_fetch = rtas_token("nvram-fetch");
141 nvram_store = rtas_token("nvram-store");
142 printk(KERN_INFO "PPC64 nvram contains %d bytes\n", nvram_size);
145 ppc_md.nvram_read = pSeries_nvram_read;
146 ppc_md.nvram_write = pSeries_nvram_write;
147 ppc_md.nvram_size = pSeries_nvram_get_size;