Can't disable tamper pins on imx6ul G3

[db42]

I can't disable the tamper pins with the TAMPER_PIN_DISABLE fuses on the G3 variant of the imx6ul processor.

The fuses can't be set and remain 0 after programming.

On the G2 it works.

[Yuri]

Hello,

  Hope the following helps.

mx6ul tamper pin to gpio

Have a great day,
Yuri

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[surendrajadhav]

Dear Yuri,

Let me know if I am using G3 version of i.MX6UL, then can I use Tamper pins for interrupt functions.

I am not using these pins as GPIO but using as PMIC and Ethernet interrupt.

Regards,

Surendra

[Yuri]

Hello,

  I am afraid it is impossible to use interrupts features of GPIO module for the 6UL-3 tamper
pins.

Regards,

Yuri. 

[shu_liu]

Yuri,

We tried to write TAMPER_DISABLE[21:20] from 00 to 11, but we it was access protect. We tried fuse prog and override. Both did not work. Logs are at below. 

Can you please let me know how to write to fuse? Thanks.

Regards,
S

=> fuse read 0 3
Reading bank 0:

Word 0x00000003: 000100d9
=> fuse prog 0 3 0x003100d9
Programming bank 0 word 0x00000003 to 0x003100d9...
Warning: Programming fuses is an irreversible operation!
This may brick your system.
Use this command only if you are sure of what you are doing!

Really perform this fuse programming? <y/N>
y
mxc_ocotp fuse_prog(): Access protect error
ERROR
=> fuse overwrite 0 3 0x003100d9
fuse - Fuse sub-system

Usage:
fuse read <bank> <word> [<cnt>] - read 1 or 'cnt' fuse words,
starting at 'word'
fuse sense <bank> <word> [<cnt>] - sense 1 or 'cnt' fuse words,
starting at 'word'
fuse prog [-y] <bank> <word> <hexval> [<hexval>...] - program 1 or
several fuse words, starting at 'word' (PERMANENT)
fuse override <bank> <word> <hexval> [<hexval>...] - override 1 or
several fuse words, starting at 'word'
=> fuse override 0 3 0x003100d9
Overriding bank 0 word 0x00000003 with 0x003100d9...
mxc_ocotp fuse_override(): Access protect error
ERROR
=> fuse override 0 3 0x00300000
Overriding bank 0 word 0x00000003 with 0x00300000...
mxc_ocotp fuse_override(): Access protect error
ERROR

[Yuri]

Hello,

     The G3 version have the TAMPER_PIN_DISABLE[1:0] bits cleared as 0x00 (blown).
No ability to change fuses.

Regards,

Yuri.

[ratnakar_vibhut]

Hi Yuri,

 Does this mean that if anybody want to use tamper pins , he has to use only G3 ?

 Can we change GPIO  to tamper pins on G2 version  ?

Thanks in advance.

- Ratnakar

[Yuri]

Correct.

~Yuri.

[db42]

I know how to disable the tamper pins. This works on the processor variants G0-G2.
On the G3 variant it does not work. I can't set the fuses, they are alway 0.

[Yuri]

Hello,

IMX6 UL G3 is already  programmed before delivery to customers.

So if you use -3 chip, these ten Tamper pins can be used as Tamper

detection, not as GPIO.

Regards,

Yuri.

[bonzo]

Yuri

Does G3 version have the TAMPER_PIN_DISABLE[1:0] bits set to 0x11 (not blown)?

Brad

[Yuri]

Hello,

   The G3 version have the TAMPER_PIN_DISABLE[1:0] bits cleared as 0x00 (blown).
No ability to change fuses.

Regards,

Yuri.

[yangzhou]

     could you tell me，how to  disable the tamper pins? when in uboot  i use fuse read 0 3 the data  is 000000ff ,when i use  md 0x21bc430 the data is 000000ff,i can`t change it with mw 0x21bc430 0x003000ff. could you tell me what you did to disable the tamper pins.  ps: now  i can`t set tamper pin as gpios .  

      thank you.

[Yuri]

Hello,  yang zhou !

Please use U-boot command

=> fuse write ...

Regards,

Yuri.