On 09/03/2014 07:14 PM, Rafał Miłecki wrote:
> 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
Could you put this into an extra function so we do not have so many #ifdefs.
> + 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)
I do not like complex function calls in if, like "if(mtd_read(...))"
could you use this instead:
err = mtd_read(..);
if (err)
> + 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;
> }
>
>
