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Commit 9d1d0864 authored by Rafał Miłecki's avatar Rafał Miłecki Committed by Ralf Baechle
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MIPS: BCM47XX: Use mtd as an alternative way/API to get NVRAM content 



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: default avatarRafał Miłecki <zajec5@gmail.com>
Acked-by: default avatarHauke Mehrtens <hauke@hauke-m.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8266/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent f4af6fb2

arch/mips/bcm47xx/nvram.c

+38 −4
Original line number Diff line number Diff line
@@ -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, u32 lim) 


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;

}