projects / linux-2.6-block.git / blame
| 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> | |
| 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> | |
| 39838299 | 20 | #include <asm/rtas.h> |
| 35e95e63 OH |
21 | #include "chrp.h" |
| 22 | ||
| 23 | static unsigned int nvram_size; | |
| 24 | static unsigned char nvram_buf[4]; | |
| 25 | static DEFINE_SPINLOCK(nvram_lock); | |
| 26 | ||
| 27 | static unsigned char chrp_nvram_read(int addr) | |
| 28 | { | |
| 39838299 PM |
29 | unsigned int done; |
| 30 | unsigned long flags; | |
| 35e95e63 OH |
31 | unsigned char ret; |
| 32 | ||
| 33 | if (addr >= nvram_size) { | |
| 34 | printk(KERN_DEBUG "%s: read addr %d > nvram_size %u\n", | |
| 35 | current->comm, addr, nvram_size); | |
| 36 | return 0xff; | |
| 37 | } | |
| 38 | spin_lock_irqsave(&nvram_lock, flags); | |
| 19fa17e5 PM |
39 | if ((rtas_call(rtas_token("nvram-fetch"), 3, 2, &done, addr, |
| 40 | __pa(nvram_buf), 1) != 0) || 1 != done) | |
| 35e95e63 OH |
41 | ret = 0xff; |
| 42 | else | |
| 43 | ret = nvram_buf[0]; | |
| 44 | spin_unlock_irqrestore(&nvram_lock, flags); | |
| 45 | ||
| 46 | return ret; | |
| 47 | } | |
| 48 | ||
| 49 | static void chrp_nvram_write(int addr, unsigned char val) | |
| 50 | { | |
| 39838299 PM |
51 | unsigned int done; |
| 52 | unsigned long flags; | |
| 35e95e63 OH |
53 | |
| 54 | if (addr >= nvram_size) { | |
| 55 | printk(KERN_DEBUG "%s: write addr %d > nvram_size %u\n", | |
| 56 | current->comm, addr, nvram_size); | |
| 57 | return; | |
| 58 | } | |
| 59 | spin_lock_irqsave(&nvram_lock, flags); | |
| 60 | nvram_buf[0] = val; | |
| 19fa17e5 PM |
61 | if ((rtas_call(rtas_token("nvram-store"), 3, 2, &done, addr, |
| 62 | __pa(nvram_buf), 1) != 0) || 1 != done) | |
| 35e95e63 OH |
63 | printk(KERN_DEBUG "rtas IO error storing 0x%02x at %d", val, addr); |
| 64 | spin_unlock_irqrestore(&nvram_lock, flags); | |
| 65 | } | |
| 66 | ||
| 67 | void __init chrp_nvram_init(void) | |
| 68 | { | |
| 69 | struct device_node *nvram; | |
| ae6b4101 JK |
70 | const unsigned int *nbytes_p; |
| 71 | unsigned int proplen; | |
| 35e95e63 OH |
72 | |
| 73 | nvram = of_find_node_by_type(NULL, "nvram"); | |
| 74 | if (nvram == NULL) | |
| 75 | return; | |
| 76 | ||
| e2eb6392 | 77 | nbytes_p = of_get_property(nvram, "#bytes", &proplen); |
| 35e95e63 OH |
78 | if (nbytes_p == NULL || proplen != sizeof(unsigned int)) |
| 79 | return; | |
| 80 | ||
| 81 | nvram_size = *nbytes_p; | |
| 82 | ||
| 83 | printk(KERN_INFO "CHRP nvram contains %u bytes\n", nvram_size); | |
| 84 | of_node_put(nvram); | |
| 85 | ||
| 86 | ppc_md.nvram_read_val = chrp_nvram_read; | |
| 87 | ppc_md.nvram_write_val = chrp_nvram_write; | |
| 88 | ||
| 89 | return; | |
| 90 | } |