| /* |
| * BCM947xx nvram variable access |
| * |
| * Copyright (C) 2005 Broadcom Corporation |
| * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org> |
| * Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de> |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License as published by the |
| * Free Software Foundation; either version 2 of the License, or (at your |
| * option) any later version. |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/string.h> |
| #include <linux/mtd/mtd.h> |
| #include <bcm47xx_nvram.h> |
| |
| #define NVRAM_MAGIC 0x48534C46 /* 'FLSH' */ |
| #define NVRAM_SPACE 0x8000 |
| |
| #define FLASH_MIN 0x00020000 /* Minimum flash size */ |
| |
| struct nvram_header { |
| u32 magic; |
| u32 len; |
| u32 crc_ver_init; /* 0:7 crc, 8:15 ver, 16:31 sdram_init */ |
| u32 config_refresh; /* 0:15 sdram_config, 16:31 sdram_refresh */ |
| u32 config_ncdl; /* ncdl values for memc */ |
| }; |
| |
| static char nvram_buf[NVRAM_SPACE]; |
| static const u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000}; |
| |
| static u32 find_nvram_size(void __iomem *end) |
| { |
| struct nvram_header __iomem *header; |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) { |
| header = (struct nvram_header *)(end - nvram_sizes[i]); |
| if (header->magic == NVRAM_MAGIC) |
| return nvram_sizes[i]; |
| } |
| |
| return 0; |
| } |
| |
| /* Probe for NVRAM header */ |
| static int nvram_find_and_copy(void __iomem *iobase, u32 lim) |
| { |
| struct nvram_header __iomem *header; |
| int i; |
| u32 off; |
| u32 *src, *dst; |
| u32 size; |
| |
| if (nvram_buf[0]) { |
| pr_warn("nvram already initialized\n"); |
| return -EEXIST; |
| } |
| |
| /* TODO: when nvram is on nand flash check for bad blocks first. */ |
| off = FLASH_MIN; |
| while (off <= lim) { |
| /* Windowed flash access */ |
| size = find_nvram_size(iobase + off); |
| if (size) { |
| header = (struct nvram_header *)(iobase + off - size); |
| goto found; |
| } |
| off <<= 1; |
| } |
| |
| /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */ |
| header = (struct nvram_header *)(iobase + 4096); |
| if (header->magic == NVRAM_MAGIC) { |
| size = NVRAM_SPACE; |
| goto found; |
| } |
| |
| header = (struct nvram_header *)(iobase + 1024); |
| if (header->magic == NVRAM_MAGIC) { |
| size = NVRAM_SPACE; |
| goto found; |
| } |
| |
| pr_err("no nvram found\n"); |
| return -ENXIO; |
| |
| found: |
| |
| if (header->len > size) |
| pr_err("The nvram size accoridng to the header seems to be bigger than the partition on flash\n"); |
| if (header->len > NVRAM_SPACE) |
| pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n", |
| header->len, NVRAM_SPACE); |
| |
| src = (u32 *) header; |
| dst = (u32 *) nvram_buf; |
| for (i = 0; i < sizeof(struct nvram_header); i += 4) |
| *dst++ = *src++; |
| for (; i < header->len && i < NVRAM_SPACE && i < size; i += 4) |
| *dst++ = le32_to_cpu(*src++); |
| memset(dst, 0x0, NVRAM_SPACE - i); |
| |
| return 0; |
| } |
| |
| /* |
| * On bcm47xx we need access to the NVRAM very early, so we can't use mtd |
| * subsystem to access flash. We can't even use platform device / driver to |
| * store memory offset. |
| * To handle this we provide following symbol. It's supposed to be called as |
| * soon as we get info about flash device, before any NVRAM entry is needed. |
| */ |
| int bcm47xx_nvram_init_from_mem(u32 base, u32 lim) |
| { |
| void __iomem *iobase; |
| int err; |
| |
| iobase = ioremap_nocache(base, lim); |
| if (!iobase) |
| return -ENOMEM; |
| |
| err = nvram_find_and_copy(iobase, lim); |
| |
| iounmap(iobase); |
| |
| return err; |
| } |
| |
| static int nvram_init(void) |
| { |
| #ifdef CONFIG_MTD |
| struct mtd_info *mtd; |
| struct nvram_header header; |
| size_t bytes_read; |
| int err, i; |
| |
| mtd = get_mtd_device_nm("nvram"); |
| if (IS_ERR(mtd)) |
| return -ENODEV; |
| |
| for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) { |
| loff_t from = mtd->size - nvram_sizes[i]; |
| |
| if (from < 0) |
| continue; |
| |
| err = mtd_read(mtd, from, sizeof(header), &bytes_read, |
| (uint8_t *)&header); |
| if (!err && header.magic == NVRAM_MAGIC) { |
| u8 *dst = (uint8_t *)nvram_buf; |
| size_t len = header.len; |
| |
| if (header.len > NVRAM_SPACE) { |
| pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n", |
| header.len, NVRAM_SPACE); |
| len = NVRAM_SPACE; |
| } |
| |
| err = mtd_read(mtd, from, len, &bytes_read, dst); |
| if (err) |
| return err; |
| memset(dst + bytes_read, 0x0, NVRAM_SPACE - bytes_read); |
| |
| return 0; |
| } |
| } |
| #endif |
| |
| return -ENXIO; |
| } |
| |
| int bcm47xx_nvram_getenv(const char *name, char *val, size_t val_len) |
| { |
| char *var, *value, *end, *eq; |
| int err; |
| |
| if (!name) |
| return -EINVAL; |
| |
| if (!nvram_buf[0]) { |
| err = nvram_init(); |
| if (err) |
| return err; |
| } |
| |
| /* Look for name=value and return value */ |
| var = &nvram_buf[sizeof(struct nvram_header)]; |
| end = nvram_buf + sizeof(nvram_buf) - 2; |
| end[0] = end[1] = '\0'; |
| for (; *var; var = value + strlen(value) + 1) { |
| eq = strchr(var, '='); |
| if (!eq) |
| break; |
| value = eq + 1; |
| if ((eq - var) == strlen(name) && |
| strncmp(var, name, (eq - var)) == 0) { |
| return snprintf(val, val_len, "%s", value); |
| } |
| } |
| return -ENOENT; |
| } |
| EXPORT_SYMBOL(bcm47xx_nvram_getenv); |
| |
| int bcm47xx_nvram_gpio_pin(const char *name) |
| { |
| int i, err; |
| char nvram_var[10]; |
| char buf[30]; |
| |
| for (i = 0; i < 32; i++) { |
| err = snprintf(nvram_var, sizeof(nvram_var), "gpio%i", i); |
| if (err <= 0) |
| continue; |
| err = bcm47xx_nvram_getenv(nvram_var, buf, sizeof(buf)); |
| if (err <= 0) |
| continue; |
| if (!strcmp(name, buf)) |
| return i; |
| } |
| return -ENOENT; |
| } |
| EXPORT_SYMBOL(bcm47xx_nvram_gpio_pin); |