--- /dev/null
+/*
+ * 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/io.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/mtd/mtd.h>
+#include <linux/bcm47xx_nvram.h>
+
+#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[] = {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_len) {
+ 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:
+ src = (u32 *)header;
+ dst = (u32 *)nvram_buf;
+ for (i = 0; i < sizeof(struct nvram_header); i += 4)
+ *dst++ = __raw_readl(src++);
+ header = (struct nvram_header *)nvram_buf;
+ nvram_len = header->len;
+ if (nvram_len > size) {
+ pr_err("The nvram size according to the header seems to be bigger than the partition on flash\n");
+ nvram_len = size;
+ }
+ if (nvram_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 - 1);
+ nvram_len = NVRAM_SPACE - 1;
+ }
+ /* proceed reading data after header */
+ for (; i < nvram_len; i += 4)
+ *dst++ = readl(src++);
+ nvram_buf[NVRAM_SPACE - 1] = '\0';
+
+ 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;
+
+ 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 (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
+ header.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");
Code Review / kvmfornfv.git / blobdiff