Root/target/linux/brcm-2.4/files/arch/mips/bcm947xx/nvram.c

1/*
2 * NVRAM variable manipulation (Linux kernel half)
3 *
4 * Copyright 2006, Broadcom Corporation
5 * All Rights Reserved.
6 *
7 * THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
8 * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
9 * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
10 * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
11 *
12 */
13
14#include <linux/config.h>
15#include <linux/init.h>
16#include <linux/module.h>
17#include <linux/kernel.h>
18#include <linux/string.h>
19#include <linux/interrupt.h>
20#include <linux/spinlock.h>
21#include <linux/slab.h>
22#include <linux/bootmem.h>
23#include <linux/wrapper.h>
24#include <linux/fs.h>
25#include <linux/miscdevice.h>
26#include <linux/mtd/mtd.h>
27#include <asm/addrspace.h>
28#include <asm/io.h>
29#include <asm/uaccess.h>
30
31#include <typedefs.h>
32#include <osl.h>
33#include <bcmendian.h>
34#include <bcmnvram.h>
35#include <sbconfig.h>
36#include <sbchipc.h>
37#include <sbutils.h>
38#include <hndmips.h>
39#include <sflash.h>
40
41/* In BSS to minimize text size and page aligned so it can be mmap()-ed */
42static char nvram_buf[NVRAM_SPACE] __attribute__((aligned(PAGE_SIZE)));
43
44/* Global SB handle */
45extern void *bcm947xx_sbh;
46extern spinlock_t bcm947xx_sbh_lock;
47
48static int cfe_env;
49extern char *cfe_env_get(char *nv_buf, const char *name);
50
51/* Convenience */
52#define sbh bcm947xx_sbh
53#define sbh_lock bcm947xx_sbh_lock
54
55/* Probe for NVRAM header */
56static void __init
57early_nvram_init(void)
58{
59    struct nvram_header *header;
60    chipcregs_t *cc;
61    struct sflash *info = NULL;
62    int i;
63    uint32 base, off, lim;
64    u32 *src, *dst;
65
66    if ((cc = sb_setcore(sbh, SB_CC, 0)) != NULL) {
67        base = KSEG1ADDR(SB_FLASH2);
68        switch (readl(&cc->capabilities) & CC_CAP_FLASH_MASK) {
69        case PFLASH:
70            lim = SB_FLASH2_SZ;
71            break;
72
73        case SFLASH_ST:
74        case SFLASH_AT:
75            if ((info = sflash_init(sbh,cc)) == NULL)
76                return;
77            lim = info->size;
78            break;
79
80        case FLASH_NONE:
81        default:
82            return;
83        }
84    } else {
85        /* extif assumed, Stop at 4 MB */
86        base = KSEG1ADDR(SB_FLASH1);
87        lim = SB_FLASH1_SZ;
88    }
89
90    /* XXX: hack for supporting the CFE environment stuff on WGT634U */
91    src = (u32 *) KSEG1ADDR(base + 8 * 1024 * 1024 - 0x2000);
92    dst = (u32 *) nvram_buf;
93    if ((lim == 0x02000000) && ((*src & 0xff00ff) == 0x000001)) {
94        printk("early_nvram_init: WGT634U NVRAM found.\n");
95
96        for (i = 0; i < 0x1ff0; i++) {
97            if (*src == 0xFFFFFFFF)
98                break;
99            *dst++ = *src++;
100        }
101        cfe_env = 1;
102        return;
103    }
104
105    off = FLASH_MIN;
106    while (off <= lim) {
107        /* Windowed flash access */
108        header = (struct nvram_header *) KSEG1ADDR(base + off - NVRAM_SPACE);
109        if (header->magic == NVRAM_MAGIC)
110            goto found;
111        off <<= 1;
112    }
113
114    /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
115    header = (struct nvram_header *) KSEG1ADDR(base + 4 * 1024);
116    if (header->magic == NVRAM_MAGIC)
117        goto found;
118    
119    header = (struct nvram_header *) KSEG1ADDR(base + 1 * 1024);
120    if (header->magic == NVRAM_MAGIC)
121        goto found;
122    
123    printk("early_nvram_init: NVRAM not found\n");
124    return;
125
126found:
127    src = (u32 *) header;
128    dst = (u32 *) nvram_buf;
129    for (i = 0; i < sizeof(struct nvram_header); i += 4)
130        *dst++ = *src++;
131    for (; i < header->len && i < NVRAM_SPACE; i += 4)
132        *dst++ = ltoh32(*src++);
133}
134
135/* Early (before mm or mtd) read-only access to NVRAM */
136static char * __init
137early_nvram_get(const char *name)
138{
139    char *var, *value, *end, *eq;
140
141    if (!name)
142        return NULL;
143
144    /* Too early? */
145    if (sbh == NULL)
146        return NULL;
147
148    if (!nvram_buf[0])
149        early_nvram_init();
150
151    if (cfe_env)
152        return cfe_env_get(nvram_buf, name);
153
154    /* Look for name=value and return value */
155    var = &nvram_buf[sizeof(struct nvram_header)];
156    end = nvram_buf + sizeof(nvram_buf) - 2;
157    end[0] = end[1] = '\0';
158    for (; *var; var = value + strlen(value) + 1) {
159        if (!(eq = strchr(var, '=')))
160            break;
161        value = eq + 1;
162        if ((eq - var) == strlen(name) && strncmp(var, name, (eq - var)) == 0)
163            return value;
164    }
165
166    return NULL;
167}
168
169static int __init
170early_nvram_getall(char *buf, int count)
171{
172    char *var, *end;
173    int len = 0;
174    
175    /* Too early? */
176    if (sbh == NULL)
177        return -1;
178
179    if (!nvram_buf[0])
180        early_nvram_init();
181
182    bzero(buf, count);
183
184    /* Write name=value\0 ... \0\0 */
185    var = &nvram_buf[sizeof(struct nvram_header)];
186    end = nvram_buf + sizeof(nvram_buf) - 2;
187    end[0] = end[1] = '\0';
188    for (; *var; var += strlen(var) + 1) {
189        if ((count - len) <= (strlen(var) + 1))
190            break;
191        len += sprintf(buf + len, "%s", var) + 1;
192    }
193
194    return 0;
195}
196
197
198char *
199nvram_get(const char *name)
200{
201    return early_nvram_get(name);
202}
203
204int
205nvram_getall(char *buf, int count)
206{
207    unsigned long flags;
208    int ret;
209
210    return early_nvram_getall(buf, count);
211}
212
213/*
214 * Search the name=value vars for a specific one and return its value.
215 * Returns NULL if not found.
216 */
217char*
218getvar(char *vars, const char *name)
219{
220    char *s;
221    int len;
222
223    len = strlen(name);
224
225    /* first look in vars[] */
226    for (s = vars; s && *s;) {
227        /* CSTYLED */
228        if ((memcmp(s, name, len) == 0) && (s[len] == '='))
229            return (&s[len+1]);
230
231        while (*s++);
232    }
233
234    /* then query nvram */
235    return (nvram_get(name));
236}
237
238/*
239 * Search the vars for a specific one and return its value as
240 * an integer. Returns 0 if not found.
241 */
242int
243getintvar(char *vars, const char *name)
244{
245    char *val;
246
247    if ((val = getvar(vars, name)) == NULL)
248        return (0);
249
250    return (simple_strtoul(val, NULL, 0));
251}
252
253

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