From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/firmware/broadcom/bcm47xx_nvram.c | 240 ++++++++++++++++++++++++++++++ 1 file changed, 240 insertions(+) create mode 100644 drivers/firmware/broadcom/bcm47xx_nvram.c (limited to 'drivers/firmware/broadcom/bcm47xx_nvram.c') diff --git a/drivers/firmware/broadcom/bcm47xx_nvram.c b/drivers/firmware/broadcom/bcm47xx_nvram.c new file mode 100644 index 000000000..bd235833b --- /dev/null +++ b/drivers/firmware/broadcom/bcm47xx_nvram.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * BCM947xx nvram variable access + * + * Copyright (C) 2005 Broadcom Corporation + * Copyright (C) 2006 Felix Fietkau + * Copyright (C) 2010-2012 Hauke Mehrtens + */ + +#include +#include +#include +#include +#include +#include +#include + +#define NVRAM_MAGIC 0x48534C46 /* 'FLSH' */ +#define NVRAM_SPACE 0x10000 +#define NVRAM_MAX_GPIO_ENTRIES 32 +#define NVRAM_MAX_GPIO_VALUE_LEN 30 + +#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 size_t nvram_len; +static const u32 nvram_sizes[] = {0x6000, 0x8000, 0xF000, 0x10000}; + +/** + * bcm47xx_nvram_is_valid - check for a valid NVRAM at specified memory + */ +static bool bcm47xx_nvram_is_valid(void __iomem *nvram) +{ + return ((struct nvram_header *)nvram)->magic == NVRAM_MAGIC; +} + +/** + * bcm47xx_nvram_copy - copy NVRAM to internal buffer + */ +static void bcm47xx_nvram_copy(void __iomem *nvram_start, size_t res_size) +{ + struct nvram_header __iomem *header = nvram_start; + size_t copy_size; + + copy_size = header->len; + if (copy_size > res_size) { + pr_err("The nvram size according to the header seems to be bigger than the partition on flash\n"); + copy_size = res_size; + } + if (copy_size >= NVRAM_SPACE) { + pr_err("nvram on flash (%zu bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n", + copy_size, NVRAM_SPACE - 1); + copy_size = NVRAM_SPACE - 1; + } + + __ioread32_copy(nvram_buf, nvram_start, DIV_ROUND_UP(copy_size, 4)); + nvram_buf[NVRAM_SPACE - 1] = '\0'; + nvram_len = copy_size; +} + +/** + * bcm47xx_nvram_find_and_copy - find NVRAM on flash mapping & copy it + */ +static int bcm47xx_nvram_find_and_copy(void __iomem *flash_start, size_t res_size) +{ + size_t flash_size; + size_t offset; + int i; + + if (nvram_len) { + pr_warn("nvram already initialized\n"); + return -EEXIST; + } + + /* TODO: when nvram is on nand flash check for bad blocks first. */ + + /* Try every possible flash size and check for NVRAM at its end */ + for (flash_size = FLASH_MIN; flash_size <= res_size; flash_size <<= 1) { + for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) { + offset = flash_size - nvram_sizes[i]; + if (bcm47xx_nvram_is_valid(flash_start + offset)) + goto found; + } + } + + /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */ + + offset = 4096; + if (bcm47xx_nvram_is_valid(flash_start + offset)) + goto found; + + offset = 1024; + if (bcm47xx_nvram_is_valid(flash_start + offset)) + goto found; + + pr_err("no nvram found\n"); + return -ENXIO; + +found: + bcm47xx_nvram_copy(flash_start + offset, res_size - offset); + + 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(base, lim); + if (!iobase) + return -ENOMEM; + + err = bcm47xx_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; + + mtd = get_mtd_device_nm("nvram"); + if (IS_ERR(mtd)) + return -ENODEV; + + err = mtd_read(mtd, 0, sizeof(header), &bytes_read, (uint8_t *)&header); + if (!err && header.magic == NVRAM_MAGIC && + header.len > sizeof(header)) { + nvram_len = header.len; + if (nvram_len >= NVRAM_SPACE) { + pr_err("nvram on flash (%zu bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n", + nvram_len, NVRAM_SPACE); + nvram_len = NVRAM_SPACE - 1; + } + + err = mtd_read(mtd, 0, nvram_len, &nvram_len, + (u8 *)nvram_buf); + return err; + } +#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_len) { + 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); + while (var < end && *var) { + 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); + var = value + strlen(value) + 1; + } + return -ENOENT; +} +EXPORT_SYMBOL(bcm47xx_nvram_getenv); + +int bcm47xx_nvram_gpio_pin(const char *name) +{ + int i, err; + char nvram_var[] = "gpioXX"; + char buf[NVRAM_MAX_GPIO_VALUE_LEN]; + + /* TODO: Optimize it to don't call getenv so many times */ + for (i = 0; i < NVRAM_MAX_GPIO_ENTRIES; 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); + +char *bcm47xx_nvram_get_contents(size_t *nvram_size) +{ + int err; + char *nvram; + + if (!nvram_len) { + err = nvram_init(); + if (err) + return NULL; + } + + *nvram_size = nvram_len - sizeof(struct nvram_header); + nvram = vmalloc(*nvram_size); + if (!nvram) + return NULL; + memcpy(nvram, &nvram_buf[sizeof(struct nvram_header)], *nvram_size); + + return nvram; +} +EXPORT_SYMBOL(bcm47xx_nvram_get_contents); + +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3