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

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

[Sean Anderson]

This is almost identical to the imx7 version, except that the register
names are different.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
---

 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
-- 
2.25.1

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

[Tom Rini]

On Thu, Feb 04, 2021 at 03:29:48PM -0500, 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@seco.com>
> ---
> 
>  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

NAK.  This needs to use the normal mechanism to populate "serial#"
directly and not abuse the old ATAG infrastructure.

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

[Sean Anderson]

On 2/4/21 3:41 PM, Tom Rini wrote:
 > On Thu, Feb 04, 2021 at 03:29:48PM -0500, 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@seco.com>
 >> ---
 >>
 >>   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
 >
 > NAK.  This needs to use the normal mechanism to populate "serial#"
 > directly and not abuse the old ATAG infrastructure.

What is the "normal" mechanism? Define something like
omap_die_id_serial which sets serial# directly? From what I can tell,
get_board_serial is the "generic" function for separating the getting of
the serial from the setting of serial#.

--Sean

[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@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
>

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

[Sean Anderson]

On 2/4/21 3:52 PM, Heinrich Schuchardt wrote:
 > 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@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?

Yes. Typically boards will use get_board_serial to set serial#. For
example, the warp7 board does

int board_late_init(void)
{
	/* ... snip ... */

#ifdef CONFIG_SERIAL_TAG
	/* Set serial# standard environment variable based on OTP settings */
	get_board_serial(&serialnr);
	snprintf(serial_string, sizeof(serial_string), "WaRP7-0x%08x%08x",
		 serialnr.low, serialnr.high);
	env_set("serial#", serial_string);
#endif

	return 0;
}

I would like to do the same on an i.MX6-based board.

--Sean

 >
 > 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
 >>
 >

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

[Tom Rini]

On Thu, Feb 04, 2021 at 03:52:51PM -0500, Sean Anderson wrote:
> 
> 
> On 2/4/21 3:41 PM, Tom Rini wrote:
> > On Thu, Feb 04, 2021 at 03:29:48PM -0500, 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@seco.com>
> >> ---
> >>
> >>   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
> >
> > NAK.  This needs to use the normal mechanism to populate "serial#"
> > directly and not abuse the old ATAG infrastructure.
> 
> What is the "normal" mechanism? Define something like
> omap_die_id_serial which sets serial# directly? From what I can tell,
> get_board_serial is the "generic" function for separating the getting of
> the serial from the setting of serial#.

The normal method is more like stm32 (arch/arm/mach-stm32mp/cpu.c) or
rockchip (arch/arm/mach-rockchip/misc.c) where there's no ATAGs legacy
design (which is where omap_die_id_serial is).

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

[Tom Rini]

On Thu, Feb 04, 2021 at 03:56:23PM -0500, Sean Anderson wrote:
> 
> 
> On 2/4/21 3:52 PM, Heinrich Schuchardt wrote:
> > 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@seco.com>
> >
> > Hello Sean,
> >
> > I tried to understand where this serial number is ending up.

See common/fdt_support.c and fdt_root().  That's the common use and way
it's populated and passed on.

> > It seems to be used by the bootm command. But shouldn't we use it to
> > define environment variable #serial instead?
> 
> Yes. Typically boards will use get_board_serial to set serial#. For
> example, the warp7 board does
> 
> int board_late_init(void)
> {
> 	/* ... snip ... */
> 
> #ifdef CONFIG_SERIAL_TAG
> 	/* Set serial# standard environment variable based on OTP settings */
> 	get_board_serial(&serialnr);
> 	snprintf(serial_string, sizeof(serial_string), "WaRP7-0x%08x%08x",
> 		 serialnr.low, serialnr.high);
> 	env_set("serial#", serial_string);
> #endif
> 
> 	return 0;
> }
> 
> I would like to do the same on an i.MX6-based board.

Please note that the WaRP7 case of mixing the serial# with some other
string is not the common / best practices case.  It's typically just the
die-ID or similar value without other text around it, which makes for an
easy generic function.  The WaRP7 case makes it harder for imx7 to have
a generic everyone gets it populated function like imx6 could have with
your patch and a few changes, and like I want to go adjust the currently
unused imx8 code to do.

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

[Heinrich Schuchardt]

On 2/4/21 9:52 PM, Sean Anderson wrote:
>
>
> On 2/4/21 3:41 PM, Tom Rini wrote:
>  > On Thu, Feb 04, 2021 at 03:29:48PM -0500, 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@seco.com>
>  >> ---
>  >>
>  >>?? 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
>  >
>  > NAK.? This needs to use the normal mechanism to populate "serial#"
>  > directly and not abuse the old ATAG infrastructure.
>
> What is the "normal" mechanism? Define something like
> omap_die_id_serial which sets serial# directly? From what I can tell,
> get_board_serial is the "generic" function for separating the getting of
> the serial from the setting of serial#.
>
> --Sean

get_board_serial() is defined as empty function in bootm.h if
CONFIG_SERIAL_TAG=n. But CONFIG_SERIAL_TAG is not documented anywhere.

board/gateworks/gw_ventana/gw_ventana.c has this comment:

#ifdef CONFIG_SERIAL_TAG
/*
  * called when setting up ATAGS before booting kernel
  * populate serialnum from the following (in order of priority):
  *   serial# env var
  *   eeprom
  */
void get_board_serial(struct tag_serialnr *serialnr)

serial# seems to be set generally in misc_init_r().
But doing this on a per board level seems to be an inadequate design for
i.mx6. The best place for i.mx6 seems to be arch_misc_init().

@Tom:
Linux Kconfig has:

CONFIG_ATAGS:
  This is the traditional way of passing data to the kernel at boot time.
  If you are solely relying on the flattened device tree (or
  the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
  to remove ATAGS support from your kernel binary.  If unsure, leave this
  to y.

CONFIG_DEPRECATED_PARAM_STRUCT
  depends on ATAGS
  This was deprecated in 2001 and announced to live on for 5 years.
  Some old boot loaders still use this way.

As this has been deprecated 20 years ago, why don't we remove it from
U-Boot?

Best regards

Heinrich

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

[Heinrich Schuchardt]

On 2/4/21 10:09 PM, Tom Rini wrote:
> On Thu, Feb 04, 2021 at 03:56:23PM -0500, Sean Anderson wrote:
>>
>>
>> On 2/4/21 3:52 PM, Heinrich Schuchardt wrote:
>>> 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@seco.com>
>>>
>>> Hello Sean,
>>>
>>> I tried to understand where this serial number is ending up.
>
> See common/fdt_support.c and fdt_root().  That's the common use and way
> it's populated and passed on.

This is where the environment variable serial# ends up. But
get_board_serial() which Sean is implementing does not populate serial#.
That is why I asked.

Best regards

Heinrich

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

[Sean Anderson]

On 2/4/21 4:04 PM, Tom Rini wrote:
 > On Thu, Feb 04, 2021 at 03:52:51PM -0500, Sean Anderson wrote:
 >>
 >>
 >> On 2/4/21 3:41 PM, Tom Rini wrote:
 >>> On Thu, Feb 04, 2021 at 03:29:48PM -0500, 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@seco.com>
 >>>> ---
 >>>>
 >>>>    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
 >>>
 >>> NAK.  This needs to use the normal mechanism to populate "serial#"
 >>> directly and not abuse the old ATAG infrastructure.
 >>
 >> What is the "normal" mechanism? Define something like
 >> omap_die_id_serial which sets serial# directly? From what I can tell,
 >> get_board_serial is the "generic" function for separating the getting of
 >> the serial from the setting of serial#.
 >
 > The normal method is more like stm32 (arch/arm/mach-stm32mp/cpu.c) or
 > rockchip (arch/arm/mach-rockchip/misc.c) where there's no ATAGs legacy
 > design (which is where omap_die_id_serial is).
 >

Thanks for the reference. It's often difficult to figure out what the
"best practice" is with so many boards added at different times.

--Sean

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

[Tom Rini]

On Thu, Feb 04, 2021 at 10:41:20PM +0100, Heinrich Schuchardt wrote:
> On 2/4/21 9:52 PM, Sean Anderson wrote:
> > 
> > 
> > On 2/4/21 3:41 PM, Tom Rini wrote:
> >  > On Thu, Feb 04, 2021 at 03:29:48PM -0500, 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@seco.com>
> >  >> ---
> >  >>
> >  >>?? 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
> >  >
> >  > NAK.? This needs to use the normal mechanism to populate "serial#"
> >  > directly and not abuse the old ATAG infrastructure.
> > 
> > What is the "normal" mechanism? Define something like
> > omap_die_id_serial which sets serial# directly? From what I can tell,
> > get_board_serial is the "generic" function for separating the getting of
> > the serial from the setting of serial#.
> > 
> > --Sean
> 
> get_board_serial() is defined as empty function in bootm.h if
> CONFIG_SERIAL_TAG=n. But CONFIG_SERIAL_TAG is not documented anywhere.

Correct, it's ATAGs related stuff, so quite old and at best may have
been documented in the README at some point.

> board/gateworks/gw_ventana/gw_ventana.c has this comment:
> 
> #ifdef CONFIG_SERIAL_TAG
> /*
>  * called when setting up ATAGS before booting kernel
>  * populate serialnum from the following (in order of priority):
>  *   serial# env var
>  *   eeprom
>  */
> void get_board_serial(struct tag_serialnr *serialnr)

Right.

> serial# seems to be set generally in misc_init_r().
> But doing this on a per board level seems to be an inadequate design for
> i.mx6. The best place for i.mx6 seems to be arch_misc_init().

Yes, there's a number of reasonable examples of where to populate
serial# from, and a few examples from when we had to support the kernel
with it.

> @Tom:
> Linux Kconfig has:
> 
> CONFIG_ATAGS:
>  This is the traditional way of passing data to the kernel at boot time.
>  If you are solely relying on the flattened device tree (or
>  the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
>  to remove ATAGS support from your kernel binary.  If unsure, leave this
>  to y.
> 
> CONFIG_DEPRECATED_PARAM_STRUCT
>  depends on ATAGS
>  This was deprecated in 2001 and announced to live on for 5 years.
>  Some old boot loaders still use this way.
> 
> As this has been deprecated 20 years ago, why don't we remove it from
> U-Boot?

The history is a lot more complex than that.  The earliest starting date
for "ATAGs is dead, use DT" would be 2010 or so when Linaro started real
work on migrating ARM to DT.  I also _think_ that deprecated param
struct note is about what predated ATAGs actually.

But, we can't universally drop ATAGs support from U-Boot as we support
hardware that runs on pre-device tree kernels only (Nokia N900) or older
VxWorks that also used ATAGs I _think__.  But we certainly have some
cases that should be cleaned up and disabled, hence my series yesterday.

-- 
Tom
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