Re: zl3073x flash: utility "family" register — 0x7C (driver) vs 0x7D (Microchip ZLS30733 reference)?

[Ivan Vecera <ivecera@redhat.com>]

Hi Mike,

On 7/8/26 7:08 PM, Mike Frandsen wrote:
> Hi Ivan,
> 
> While porting the zl3073x flash sequence to a small userspace tool for the
> ZL80732 (Azurite), we noticed a discrepancy between the mainline driver and
> Microchip's own reference flasher about which register holds the flash
> utility's "family" byte:
> 
> - drivers/dpll/zl3073x/flash.c (as of 01e0e8b6a2d7) reads the family from
>    register 0x7C and checks for 0x21;
> - Microchip's ZLS30733 reference code (shipped in their AZFB firmware
>    bundle) reads the family from 0x7D (masking the low 7 bits) and treats
>    0x7C as a different field.

In the reference code there is a confusion... There are the following
constants defined:

static const Uint32T HOST_REG_VERSION = 0x007C;
static const Uint32T HOST_REG_FAMILY = 0x007D;

These constants are nowhere referenced and the code uses hardcoded
values:

     utilityHash = HostRegister_read(pContext, 0x78, 4);
     utilityFam = HostRegister_read(pContext, 0x7c, 1);
     utilityRel = HostRegister_read(pContext, 0x7d, 1);
     ...
     if (utilityFam != 0x21)
     {
           status = ZL303XX_INVALID_OPERATION;
           ...
     }

So the family code reported by the utility at register address 0x7c and
should contain the value of 0x21.

> We have not yet confirmed on hardware which location reports 0x21 after
> the utility loads (our port defensively accepts either). Do you know
> which location is authoritative per Microchip's documentation — and if it
> is 0x7D, whether flash.c's check works today by coincidence of the utility
> images it has been used with?

There is no official documentation for this :-( but according my test,
all known utility versions reports 0x21 in reg 0x7c.

Thanks,
Ivan