Commit | Line | Data |
---|---|---|
de6cc651 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
5f5b4e66 | 2 | /* |
f3f66f59 | 3 | * memory mapped NVRAM |
5f5b4e66 UB |
4 | * |
5 | * (C) Copyright IBM Corp. 2005 | |
6 | * | |
7 | * Authors : Utz Bacher <utz.bacher@de.ibm.com> | |
5f5b4e66 UB |
8 | */ |
9 | ||
10 | #include <linux/fs.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/spinlock.h> | |
14 | #include <linux/types.h> | |
15 | ||
16 | #include <asm/machdep.h> | |
17 | #include <asm/nvram.h> | |
18 | #include <asm/prom.h> | |
19 | ||
f3f66f59 AB |
20 | static void __iomem *mmio_nvram_start; |
21 | static long mmio_nvram_len; | |
34af946a | 22 | static DEFINE_SPINLOCK(mmio_nvram_lock); |
5f5b4e66 | 23 | |
f3f66f59 | 24 | static ssize_t mmio_nvram_read(char *buf, size_t count, loff_t *index) |
5f5b4e66 UB |
25 | { |
26 | unsigned long flags; | |
27 | ||
f3f66f59 | 28 | if (*index >= mmio_nvram_len) |
5f5b4e66 | 29 | return 0; |
f3f66f59 AB |
30 | if (*index + count > mmio_nvram_len) |
31 | count = mmio_nvram_len - *index; | |
5f5b4e66 | 32 | |
f3f66f59 | 33 | spin_lock_irqsave(&mmio_nvram_lock, flags); |
5f5b4e66 | 34 | |
f3f66f59 | 35 | memcpy_fromio(buf, mmio_nvram_start + *index, count); |
5f5b4e66 | 36 | |
f3f66f59 | 37 | spin_unlock_irqrestore(&mmio_nvram_lock, flags); |
5f5b4e66 UB |
38 | |
39 | *index += count; | |
40 | return count; | |
41 | } | |
42 | ||
690a2d07 MW |
43 | static unsigned char mmio_nvram_read_val(int addr) |
44 | { | |
45 | unsigned long flags; | |
46 | unsigned char val; | |
47 | ||
48 | if (addr >= mmio_nvram_len) | |
49 | return 0xff; | |
50 | ||
51 | spin_lock_irqsave(&mmio_nvram_lock, flags); | |
52 | ||
53 | val = ioread8(mmio_nvram_start + addr); | |
54 | ||
55 | spin_unlock_irqrestore(&mmio_nvram_lock, flags); | |
56 | ||
57 | return val; | |
58 | } | |
59 | ||
f3f66f59 | 60 | static ssize_t mmio_nvram_write(char *buf, size_t count, loff_t *index) |
5f5b4e66 UB |
61 | { |
62 | unsigned long flags; | |
63 | ||
f3f66f59 | 64 | if (*index >= mmio_nvram_len) |
5f5b4e66 | 65 | return 0; |
f3f66f59 AB |
66 | if (*index + count > mmio_nvram_len) |
67 | count = mmio_nvram_len - *index; | |
5f5b4e66 | 68 | |
f3f66f59 | 69 | spin_lock_irqsave(&mmio_nvram_lock, flags); |
5f5b4e66 | 70 | |
f3f66f59 | 71 | memcpy_toio(mmio_nvram_start + *index, buf, count); |
5f5b4e66 | 72 | |
f3f66f59 | 73 | spin_unlock_irqrestore(&mmio_nvram_lock, flags); |
5f5b4e66 UB |
74 | |
75 | *index += count; | |
76 | return count; | |
77 | } | |
78 | ||
7c98bd72 | 79 | static void mmio_nvram_write_val(int addr, unsigned char val) |
690a2d07 MW |
80 | { |
81 | unsigned long flags; | |
82 | ||
83 | if (addr < mmio_nvram_len) { | |
84 | spin_lock_irqsave(&mmio_nvram_lock, flags); | |
85 | ||
86 | iowrite8(val, mmio_nvram_start + addr); | |
87 | ||
88 | spin_unlock_irqrestore(&mmio_nvram_lock, flags); | |
89 | } | |
90 | } | |
91 | ||
f3f66f59 | 92 | static ssize_t mmio_nvram_get_size(void) |
5f5b4e66 | 93 | { |
f3f66f59 | 94 | return mmio_nvram_len; |
5f5b4e66 UB |
95 | } |
96 | ||
f3f66f59 | 97 | int __init mmio_nvram_init(void) |
5f5b4e66 UB |
98 | { |
99 | struct device_node *nvram_node; | |
5f5b4e66 | 100 | unsigned long nvram_addr; |
6984ee79 | 101 | struct resource r; |
5f5b4e66 UB |
102 | int ret; |
103 | ||
5f5b4e66 | 104 | nvram_node = of_find_node_by_type(NULL, "nvram"); |
411e689d BH |
105 | if (!nvram_node) |
106 | nvram_node = of_find_compatible_node(NULL, NULL, "nvram"); | |
6984ee79 BH |
107 | if (!nvram_node) { |
108 | printk(KERN_WARNING "nvram: no node found in device-tree\n"); | |
109 | return -ENODEV; | |
110 | } | |
111 | ||
112 | ret = of_address_to_resource(nvram_node, 0, &r); | |
113 | if (ret) { | |
114 | printk(KERN_WARNING "nvram: failed to get address (err %d)\n", | |
115 | ret); | |
5f5b4e66 | 116 | goto out; |
6984ee79 BH |
117 | } |
118 | nvram_addr = r.start; | |
28f65c11 | 119 | mmio_nvram_len = resource_size(&r); |
6984ee79 | 120 | if ( (!mmio_nvram_len) || (!nvram_addr) ) { |
00d70419 | 121 | printk(KERN_WARNING "nvram: address or length is 0\n"); |
6984ee79 | 122 | ret = -EIO; |
5f5b4e66 | 123 | goto out; |
6984ee79 | 124 | } |
5f5b4e66 | 125 | |
f3f66f59 | 126 | mmio_nvram_start = ioremap(nvram_addr, mmio_nvram_len); |
6984ee79 BH |
127 | if (!mmio_nvram_start) { |
128 | printk(KERN_WARNING "nvram: failed to ioremap\n"); | |
129 | ret = -ENOMEM; | |
5f5b4e66 | 130 | goto out; |
6984ee79 | 131 | } |
5f5b4e66 | 132 | |
6984ee79 BH |
133 | printk(KERN_INFO "mmio NVRAM, %luk at 0x%lx mapped to %p\n", |
134 | mmio_nvram_len >> 10, nvram_addr, mmio_nvram_start); | |
5f5b4e66 | 135 | |
690a2d07 MW |
136 | ppc_md.nvram_read_val = mmio_nvram_read_val; |
137 | ppc_md.nvram_write_val = mmio_nvram_write_val; | |
f3f66f59 AB |
138 | ppc_md.nvram_read = mmio_nvram_read; |
139 | ppc_md.nvram_write = mmio_nvram_write; | |
140 | ppc_md.nvram_size = mmio_nvram_get_size; | |
5f5b4e66 UB |
141 | |
142 | out: | |
143 | of_node_put(nvram_node); | |
144 | return ret; | |
145 | } |