2 * BCM947xx nvram variable access
4 * Copyright (C) 2005 Broadcom Corporation
5 * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
6 * Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
14 #include <linux/types.h>
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/mtd/mtd.h>
19 #include <linux/bcm47xx_nvram.h>
21 #define NVRAM_MAGIC 0x48534C46 /* 'FLSH' */
22 #define NVRAM_SPACE 0x8000
23 #define NVRAM_MAX_GPIO_ENTRIES 32
24 #define NVRAM_MAX_GPIO_VALUE_LEN 30
26 #define FLASH_MIN 0x00020000 /* Minimum flash size */
31 u32 crc_ver_init
; /* 0:7 crc, 8:15 ver, 16:31 sdram_init */
32 u32 config_refresh
; /* 0:15 sdram_config, 16:31 sdram_refresh */
33 u32 config_ncdl
; /* ncdl values for memc */
36 static char nvram_buf
[NVRAM_SPACE
];
37 static const u32 nvram_sizes
[] = {0x8000, 0xF000, 0x10000};
39 static u32
find_nvram_size(void __iomem
*end
)
41 struct nvram_header __iomem
*header
;
44 for (i
= 0; i
< ARRAY_SIZE(nvram_sizes
); i
++) {
45 header
= (struct nvram_header
*)(end
- nvram_sizes
[i
]);
46 if (header
->magic
== NVRAM_MAGIC
)
47 return nvram_sizes
[i
];
53 /* Probe for NVRAM header */
54 static int nvram_find_and_copy(void __iomem
*iobase
, u32 lim
)
56 struct nvram_header __iomem
*header
;
63 pr_warn("nvram already initialized\n");
67 /* TODO: when nvram is on nand flash check for bad blocks first. */
70 /* Windowed flash access */
71 size
= find_nvram_size(iobase
+ off
);
73 header
= (struct nvram_header
*)(iobase
+ off
- size
);
79 /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
80 header
= (struct nvram_header
*)(iobase
+ 4096);
81 if (header
->magic
== NVRAM_MAGIC
) {
86 header
= (struct nvram_header
*)(iobase
+ 1024);
87 if (header
->magic
== NVRAM_MAGIC
) {
92 pr_err("no nvram found\n");
96 if (header
->len
> size
)
97 pr_err("The nvram size accoridng to the header seems to be bigger than the partition on flash\n");
98 if (header
->len
> NVRAM_SPACE
)
99 pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
100 header
->len
, NVRAM_SPACE
);
103 dst
= (u32
*)nvram_buf
;
104 for (i
= 0; i
< sizeof(struct nvram_header
); i
+= 4)
105 *dst
++ = __raw_readl(src
++);
106 for (; i
< header
->len
&& i
< NVRAM_SPACE
&& i
< size
; i
+= 4)
107 *dst
++ = readl(src
++);
113 * On bcm47xx we need access to the NVRAM very early, so we can't use mtd
114 * subsystem to access flash. We can't even use platform device / driver to
115 * store memory offset.
116 * To handle this we provide following symbol. It's supposed to be called as
117 * soon as we get info about flash device, before any NVRAM entry is needed.
119 int bcm47xx_nvram_init_from_mem(u32 base
, u32 lim
)
121 void __iomem
*iobase
;
124 iobase
= ioremap_nocache(base
, lim
);
128 err
= nvram_find_and_copy(iobase
, lim
);
135 static int nvram_init(void)
138 struct mtd_info
*mtd
;
139 struct nvram_header header
;
143 mtd
= get_mtd_device_nm("nvram");
147 for (i
= 0; i
< ARRAY_SIZE(nvram_sizes
); i
++) {
148 loff_t from
= mtd
->size
- nvram_sizes
[i
];
153 err
= mtd_read(mtd
, from
, sizeof(header
), &bytes_read
,
155 if (!err
&& header
.magic
== NVRAM_MAGIC
) {
156 u8
*dst
= (uint8_t *)nvram_buf
;
157 size_t len
= header
.len
;
159 if (header
.len
> NVRAM_SPACE
) {
160 pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
161 header
.len
, NVRAM_SPACE
);
165 err
= mtd_read(mtd
, from
, len
, &bytes_read
, dst
);
177 int bcm47xx_nvram_getenv(const char *name
, char *val
, size_t val_len
)
179 char *var
, *value
, *end
, *eq
;
191 /* Look for name=value and return value */
192 var
= &nvram_buf
[sizeof(struct nvram_header
)];
193 end
= nvram_buf
+ sizeof(nvram_buf
) - 2;
196 for (; *var
; var
= value
+ strlen(value
) + 1) {
197 data_left
= end
- var
;
199 eq
= strnchr(var
, data_left
, '=');
203 if (eq
- var
== strlen(name
) &&
204 strncmp(var
, name
, eq
- var
) == 0)
205 return snprintf(val
, val_len
, "%s", value
);
209 EXPORT_SYMBOL(bcm47xx_nvram_getenv
);
211 int bcm47xx_nvram_gpio_pin(const char *name
)
214 char nvram_var
[] = "gpioXX";
215 char buf
[NVRAM_MAX_GPIO_VALUE_LEN
];
217 /* TODO: Optimize it to don't call getenv so many times */
218 for (i
= 0; i
< NVRAM_MAX_GPIO_ENTRIES
; i
++) {
219 err
= snprintf(nvram_var
, sizeof(nvram_var
), "gpio%i", i
);
222 err
= bcm47xx_nvram_getenv(nvram_var
, buf
, sizeof(buf
));
225 if (!strcmp(name
, buf
))
230 EXPORT_SYMBOL(bcm47xx_nvram_gpio_pin
);
232 MODULE_LICENSE("GPLv2");