[PATCH v3 0/2] Meson NAND: waiting w/o wired ready/busy pin

[Arseniy Krasnov]

Main thing that this patchset adds is support for waiting for command
completion when there is no wired ready/busy pin. This is implemented
by using Meson specific command which operates without wired pin, but
supports interrupt driven waiting (default way for waiting without
hardware pin is 'nand_soft_waitrdy()' which uses software loop instead
of interrupt). To select which mode to use during driver initialization,
common NAND controller property is used - 'nand-rb'. It is described in
'nand-controller.yaml'. But for Meson, its description was missed in
'amlogic,meson-nand.yaml', so this patchset also adds support for it.

Patch for bindings was tested with dt_binding_check and dtbs_check.

Links:
 v1 (as two separate patches):
  https://lore.kernel.org/linux-mtd/20230606193507.35024-1-AVKrasnov@sberdevices.ru/
  https://lore.kernel.org/linux-mtd/20230607073015.1280085-1-AVKrasnov@sberdevices.ru/

 v2 (tagged as v1, but consider it as v2):
  https://lore.kernel.org/linux-mtd/20230607145026.2899547-1-AVKrasnov@sberdevices.ru/

Changelog:
 v1 -> v2:
  * Two separate patches:
    For bindings: https://lore.kernel.org/linux-mtd/20230606193507.35024-1-AVKrasnov@sberdevices.ru/
    For driver: https://lore.kernel.org/linux-mtd/20230607073015.1280085-1-AVKrasnov@sberdevices.ru/
    Now fixed/updated and combined to this patchset with v1 version.
  
  * In binding patch:
    * Invalid type of 'nand-rb' is fixed, it was 'bool', now it is 'uint32 array' as required. Also
      new declaration of 'nand-rb' contains several restrictions like number of elements and min/max
      value of elements.
    * Location of 'nand-rb' is moved from the controller object to the chip object as required.
  
  * In driver patch:
    * Update comment which describes when it is needed to send NAND_CMD_READ0 to
      leave command waiting loop.
    * Change type of 'no_rb_pin' to 'bool' as in v1. Now it is just a flag which selects
      mode to wait for command completion.

 v2 -> v3:
  * In binding patch:
    * 'minimum' property is dropped, because 'nand-rb' is unsigned.

  * In driver patch:
    * Logic of 'no_rb_pin' parsing is reworked a little bit. For example to return error
      code from 'of_property_read_u32()'.

Arseniy Krasnov (2):
  dt-bindings: nand: meson: Fix 'nand-rb' property
  mtd: rawnand: meson: waiting w/o wired ready/busy pin

 .../bindings/mtd/amlogic,meson-nand.yaml      |  6 ++
 drivers/mtd/nand/raw/meson_nand.c             | 77 ++++++++++++++++++-
 2 files changed, 79 insertions(+), 4 deletions(-)

-- 
2.35.0