regulator: mt6358: use regmap helper to read fixed LDO calibration

The "fixed" LDOs with output voltage calibration use
mt6358_get_buck_voltage_sel as their get_voltage_sel op, but the
MT6358_REG_FIXED and MT6366_REG_FIXED entries do not populate
da_vsel_reg/da_vsel_mask. The op therefore reads register 0x0 with a
zero mask and shifts the result by ffs(0) - 1 = -1, which is undefined
behaviour and gets flagged by UBSAN on every boot on MT6366 boards:

  UBSAN: shift-out-of-bounds in drivers/regulator/mt6358-regulator.c:384:38
  shift exponent -1 is negative
  Call trace:
   mt6358_get_buck_voltage_sel+0xc8/0x120
   regulator_get_voltage_rdev+0x70/0x170
   set_machine_constraints+0x504/0xc38
   regulator_register+0x324/0xc68

Besides the undefined shift, the returned selector is always 0, so the
actual calibration offset programmed in <reg>_ANA_CON0 is never
reported.

The descriptor already carries the correct vsel_reg/vsel_mask (the
ANA_CON0 calibration field), matching the regulator_set_voltage_sel_regmap
op already in use. Read the selector back through
regulator_get_voltage_sel_regmap instead.

Fixes: cf08fa74c716 ("regulator: mt6358: Add output voltage fine tuning to fixed regulators")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Chen-Yu Tsai <wens@kernel.org>
Tested-by: Chen-Yu Tsai <wens@kernel.org>
Link: https://patch.msgid.link/dcd98d81dede338c9bbb9700a9613c848b702e49.1784336005.git.daniel@makrotopia.org
Signed-off-by: Mark Brown <broonie@kernel.org>

0 files changed, 0 insertions, 0 deletions