[PATCH 0/2] regulator: mt6363: Fix the regmap value width and the VSRAM LDO registers

[GIBEOM LEE (이기범)]

These patches fix two problems in the MT6363 regulator driver that can be
seen from the code. They are on top of regulator for-next, where the driver
is the same as in master and v7.2.12.

Patch 1: the registers have 8 bits but the regmap has 16-bit values, so
every write also writes the next register. For example, disabling one of
VS2 and VBUCK1-7 also disables VS1, VS3 and VSRAM_{DIGRF,MDFE,MODEM}. The
MT6373 driver on the list has 16-bit values too, so its next version will
want the same change.

Patch 2: VSRAM_{CPUB,CPUM,CPUL,APU} use the enable and low power registers
of the BUCK1 group instead of their own, so disabling one of them disables
VS1.

Testing: none of this has run on hardware, because the bootloader of my
board (Lenovo TB375FC, MT6897) is still locked. Each patch builds with W=1.
The driver file also ran unchanged in user space, against a model of the
registers made from MediaTek's header and driver, before and after the
patches:

 - 16 of the 33 checks of the model fail before and pass after. The 9 that
   still fail are about the VEMC voltage callbacks and the overcurrent
   handling, for which I have fixes that I would like to test first.
 - ASan reports a stack buffer overflow in the BUCK_TOP key write before
   patch 1, and nothing after it.
 - The resolved table of the 35 rails differs from MediaTek's driver in 8
   entries before patch 2, and in none after it.

The model comes from MediaTek's sources, so it does not show how the chip
really behaves. A Tested-by from anyone with an MT8196 or MT6991 board would
be very welcome.

How this was made: Claude (claude-opus-5-5, an AI coding assistant) found
both problems while comparing the driver with MediaTek's driver in the
OnePlus MT6897 kernel, during a longer session of porting mainline Linux to
this tablet. It wrote the patches, their changelogs and this letter, and it
ran the checks above. I reviewed the result before signing off.

GIBEOM LEE (이기범) (2):
  regulator: mt6363: Use 8-bit regmap values
  regulator: mt6363: Fix the registers of the VSRAM CPU and APU LDOs

 drivers/regulator/mt6363-regulator.c | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)