[PATCH] ARM: mx6: Add function to read UNIQUE_ID

[Heinrich Schuchardt]

On 2/4/21 9:29 PM, Sean Anderson wrote:
> This is almost identical to the imx7 version, except that the register
> names are different.
>
> Signed-off-by: Sean Anderson <sean.anderson at seco.com>

Hello Sean,

I tried to understand where this serial number is ending up.

It seems to be used by the bootm command. But shouldn't we use it to
define environment variable #serial instead?

Best regards

Heinrich

> ---
>
>   arch/arm/mach-imx/mx6/soc.c | 33 +++++++++++++++++++++++++++++++++
>   1 file changed, 33 insertions(+)
>
> diff --git a/arch/arm/mach-imx/mx6/soc.c b/arch/arm/mach-imx/mx6/soc.c
> index bf6dddfdc9..cb729be46f 100644
> --- a/arch/arm/mach-imx/mx6/soc.c
> +++ b/arch/arm/mach-imx/mx6/soc.c
> @@ -11,6 +11,7 @@
>   #include <linux/delay.h>
>   #include <linux/errno.h>
>   #include <asm/io.h>
> +#include <asm/setup.h>
>   #include <asm/arch/imx-regs.h>
>   #include <asm/arch/clock.h>
>   #include <asm/arch/sys_proto.h>
> @@ -705,6 +706,38 @@ int arch_misc_init(void)
>   }
>   #endif
>
> +#ifdef CONFIG_SERIAL_TAG
> +/*
> + * UNIQUE_ID describes a unique ID based on silicon wafer
> + * and die X/Y position
> + *
> + * UNIQUE_ID offset 0x410
> + * 31:0 fuse 0
> + * FSL-wide unique, encoded LOT ID STD II/SJC CHALLENGE/ Unique ID
> + *
> + * UNIQUE_ID offset 0x420
> + * 31:24 fuse 1
> + * The X-coordinate of the die location on the wafer/SJC CHALLENGE/ Unique ID
> + * 23:16 fuse 1
> + * The Y-coordinate of the die location on the wafer/SJC CHALLENGE/ Unique ID
> + * 15:11 fuse 1
> + * The wafer number of the wafer on which the device was fabricated/SJC
> + * CHALLENGE/ Unique ID
> + * 10:0 fuse 1
> + * FSL-wide unique, encoded LOT ID STD II/SJC CHALLENGE/ Unique ID
> + */
> +void get_board_serial(struct tag_serialnr *serialnr)
> +{
> +	struct ocotp_regs *ocotp = (struct ocotp_regs *)OCOTP_BASE_ADDR;
> +	struct fuse_bank *bank = &ocotp->bank[0];
> +	struct fuse_bank0_regs *fuse =
> +		(struct fuse_bank0_regs *)bank->fuse_regs;
> +
> +	serialnr->low = fuse->uid_low;
> +	serialnr->high = fuse->uid_high;
> +}
> +#endif
> +
>   /*
>    * gpr_init() function is common for boards using MX6S, MX6DL, MX6D,
>    * MX6Q and MX6QP processors
>