| Utz Bacher | 5f5b4e6 | 2005-06-23 09:43:31 +1000 | [diff] [blame] | 1 | /* |
| 2 | * NVRAM for CPBW |
| 3 | * |
| 4 | * (C) Copyright IBM Corp. 2005 |
| 5 | * |
| 6 | * Authors : Utz Bacher <utz.bacher@de.ibm.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2, or (at your option) |
| 11 | * any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 21 | */ |
| 22 | |
| 23 | #include <linux/fs.h> |
| 24 | #include <linux/init.h> |
| 25 | #include <linux/kernel.h> |
| 26 | #include <linux/spinlock.h> |
| 27 | #include <linux/types.h> |
| 28 | |
| 29 | #include <asm/machdep.h> |
| 30 | #include <asm/nvram.h> |
| 31 | #include <asm/prom.h> |
| 32 | |
| 33 | static void __iomem *bpa_nvram_start; |
| 34 | static long bpa_nvram_len; |
| 35 | static spinlock_t bpa_nvram_lock = SPIN_LOCK_UNLOCKED; |
| 36 | |
| 37 | static ssize_t bpa_nvram_read(char *buf, size_t count, loff_t *index) |
| 38 | { |
| 39 | unsigned long flags; |
| 40 | |
| 41 | if (*index >= bpa_nvram_len) |
| 42 | return 0; |
| 43 | if (*index + count > bpa_nvram_len) |
| 44 | count = bpa_nvram_len - *index; |
| 45 | |
| 46 | spin_lock_irqsave(&bpa_nvram_lock, flags); |
| 47 | |
| 48 | memcpy_fromio(buf, bpa_nvram_start + *index, count); |
| 49 | |
| 50 | spin_unlock_irqrestore(&bpa_nvram_lock, flags); |
| 51 | |
| 52 | *index += count; |
| 53 | return count; |
| 54 | } |
| 55 | |
| 56 | static ssize_t bpa_nvram_write(char *buf, size_t count, loff_t *index) |
| 57 | { |
| 58 | unsigned long flags; |
| 59 | |
| 60 | if (*index >= bpa_nvram_len) |
| 61 | return 0; |
| 62 | if (*index + count > bpa_nvram_len) |
| 63 | count = bpa_nvram_len - *index; |
| 64 | |
| 65 | spin_lock_irqsave(&bpa_nvram_lock, flags); |
| 66 | |
| 67 | memcpy_toio(bpa_nvram_start + *index, buf, count); |
| 68 | |
| 69 | spin_unlock_irqrestore(&bpa_nvram_lock, flags); |
| 70 | |
| 71 | *index += count; |
| 72 | return count; |
| 73 | } |
| 74 | |
| 75 | static ssize_t bpa_nvram_get_size(void) |
| 76 | { |
| 77 | return bpa_nvram_len; |
| 78 | } |
| 79 | |
| 80 | int __init bpa_nvram_init(void) |
| 81 | { |
| 82 | struct device_node *nvram_node; |
| 83 | unsigned long *buffer; |
| 84 | int proplen; |
| 85 | unsigned long nvram_addr; |
| 86 | int ret; |
| 87 | |
| 88 | ret = -ENODEV; |
| 89 | nvram_node = of_find_node_by_type(NULL, "nvram"); |
| 90 | if (!nvram_node) |
| 91 | goto out; |
| 92 | |
| 93 | ret = -EIO; |
| 94 | buffer = (unsigned long *)get_property(nvram_node, "reg", &proplen); |
| 95 | if (proplen != 2*sizeof(unsigned long)) |
| 96 | goto out; |
| 97 | |
| 98 | ret = -ENODEV; |
| 99 | nvram_addr = buffer[0]; |
| 100 | bpa_nvram_len = buffer[1]; |
| 101 | if ( (!bpa_nvram_len) || (!nvram_addr) ) |
| 102 | goto out; |
| 103 | |
| 104 | bpa_nvram_start = ioremap(nvram_addr, bpa_nvram_len); |
| 105 | if (!bpa_nvram_start) |
| 106 | goto out; |
| 107 | |
| 108 | printk(KERN_INFO "BPA NVRAM, %luk mapped to %p\n", |
| 109 | bpa_nvram_len >> 10, bpa_nvram_start); |
| 110 | |
| 111 | ppc_md.nvram_read = bpa_nvram_read; |
| 112 | ppc_md.nvram_write = bpa_nvram_write; |
| 113 | ppc_md.nvram_size = bpa_nvram_get_size; |
| 114 | |
| 115 | out: |
| 116 | of_node_put(nvram_node); |
| 117 | return ret; |
| 118 | } |