[PATCH 0/2] pinctrl: sunxi: A733: use the two-bit I/O voltage fields

[Vinicius Pedrosa]

Hi,

this follows my question in [1]. Andre asked why not extend the A733 I/O
bias code to two bits instead of switching it off, so patch 1 does that
for the main PIO and patch 2 gives the A733-R its own descriptor, as it
cannot share the A523-R encoding.

I have not seen the board fail with the current code, and no A733 board
DT upstream uses these supplies yet. What I have is the old and the new
helper, copied from the driver, run on the host with register values
read (read-only) from a Cubie A7Z, silicon revision B:

  PIO SEL 0x01155550: a PJ request at 1.8 V gives 0x01155750 with the
  old code (PE goes from automatic to fixed 1.8 V), unchanged with the
  new one.

  R-PIO SEL 0x000aaaaa: a PL request at 3.3 V gives 0x000aaaab with the
  old code (fixed 1.8 V), plus a read-modify-write of +0x344 that the
  manual does not list. The new code leaves both alone.

With both patches the kernel boots on the A7Z (RAM boot of an rc6-based
kernel): UART0 and MMC0 work and the voltage selection registers are
unchanged.

PF and PI are not programmed, and neither is any silicon revision other
than B, as reported by SMCCC. The A523 variants behave as before.

I found nothing to change in the DT binding: the a733-r compatible has
no a523-r fallback and the schema checks pass for both controllers.
Andre, if you meant something else there, please tell me.

[1] https://lore.kernel.org/r/20261008194719.328146-1-vinicius.eduardo.pedrosa@gmail.com

Vinicius Pedrosa (2):
  pinctrl: sunxi: a733: program the two-bit I/O voltage fields
  pinctrl: sunxi: a733-r: use the A733 I/O voltage fields

 drivers/pinctrl/sunxi/pinctrl-sun55i-a523-r.c | 26 ++++++++-
 drivers/pinctrl/sunxi/pinctrl-sun60i-a733.c   | 15 ++++-
 drivers/pinctrl/sunxi/pinctrl-sunxi.c         | 57 +++++++++++++++++++
 drivers/pinctrl/sunxi/pinctrl-sunxi.h         |  6 ++
 4 files changed, 101 insertions(+), 3 deletions(-)


base-commit: bdacd2542f3c1b2b411fa86ee1f39de19cce6562
-- 
2.43.0