NVRAM can be read using magic memory offset, but after all it's just a
flash partition. On platforms where NVRAM isn't needed early we can get
it using mtd subsystem.
Signed-off-by: Rafał Miłecki <zajec5@xxxxxxxxx>
---
arch/mips/bcm47xx/nvram.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/arch/mips/bcm47xx/nvram.c b/arch/mips/bcm47xx/nvram.c
index 8ea2116..9ab74db 100644
--- a/arch/mips/bcm47xx/nvram.c
+++ b/arch/mips/bcm47xx/nvram.c
@@ -16,6 +16,7 @@
#include <linux/ssb/ssb.h>
#include <linux/kernel.h>
#include <linux/string.h>
+#include <linux/mtd/mtd.h>
#include <asm/addrspace.h>
#include <bcm47xx_nvram.h>
#include <asm/mach-bcm47xx/bcm47xx.h>
@@ -148,6 +149,13 @@ static int nvram_init_bcma(void)
static int nvram_init(void)
{
+#ifdef CONFIG_MTD
+ struct mtd_info *mtd;
+ struct nvram_header header;
+ size_t bytes_read;
+ int i;
+#endif
+
switch (bcm47xx_bus_type) {
#ifdef CONFIG_BCM47XX_SSB
case BCM47XX_BUS_TYPE_SSB:
@@ -158,6 +166,38 @@ static int nvram_init(void)
return nvram_init_bcma();
#endif
}
+
+#ifdef CONFIG_MTD
+ 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;
+
+ if (mtd_read(mtd, from, sizeof(header), &bytes_read,
+ (uint8_t *)&header) < 0)
+ continue;
+ if (header.magic == NVRAM_HEADER) {
+ 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;
+ }
+
+ if (mtd_read(mtd, from, len, &bytes_read, dst) < 0)
+ continue;
+ memset(dst + bytes_read, 0x0, NVRAM_SPACE - bytes_read);
+ }
+ }
+#endif
+
return -ENXIO;
}
--
1.8.4.5
