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From 9d1d08646af4491aec41d40341930b9bfd62ffa9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
Date: Wed, 29 Oct 2014 10:05:06 +0100
Subject: [PATCH] MIPS: BCM47XX: Use mtd as an alternative way/API to get NVRAM
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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@gmail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8266/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
arch/mips/bcm47xx/nvram.c | 42 ++++++++++++++++++++++++++++++++++++++----
1 file changed, 38 insertions(+), 4 deletions(-)
--- a/arch/mips/bcm47xx/nvram.c
+++ b/arch/mips/bcm47xx/nvram.c
@@ -13,12 +13,10 @@
#include <linux/types.h>
#include <linux/module.h>
-#include <linux/ssb/ssb.h>
#include <linux/kernel.h>
#include <linux/string.h>
-#include <asm/addrspace.h>
+#include <linux/mtd/mtd.h>
#include <bcm47xx_nvram.h>
-#include <asm/mach-bcm47xx/bcm47xx.h>
static char nvram_buf[NVRAM_SPACE];
static const u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000};
@@ -123,7 +121,43 @@ int bcm47xx_nvram_init_from_mem(u32 base
static int nvram_init(void)
{
- /* TODO: Look for MTD "nvram" partition */
+#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_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;
+ }
+
+ 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;
}
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