[PATCH v11 0/4] Microchip soft ip corePWM driver

[Conor Dooley]

Hey Uwe, all,

~6.0-rc1 has rolled around so here is the promised v8v9~.
v11 is based on 6.0 stuff still & there will be a change to the dts
patch in v6.1, but I did a test merge and there was nothing to resolve.
I'll take the dts change myself just to be on the safe side.

The pre 6.0-rc1 cover letter/series is here:
https://lore.kernel.org/linux-pwm/20220721172109.941900-1-mail@xxxxxxxxxxx


Thanks,
Conor.

Changes since v10:
- reword some comments
- try to assign the period if a disable is requested
- drop a cast around a u8 -> u16 conversion
- fix a check on period_steps that should be on the hw_ variant
- split up the period calculation in get_state() to fix the result on
  32 bit
- add a rate variable in get_state() to only call get_rate() once.
- redo the locking as suggested to make it more straightforward.
- stop checking for enablement in get_state() that was working around
 intended behaviour of the sysfs interface

Changes since v9:
- fixed the missing unlock that Dan reported

Changes since v8:
- fixed a(nother) raw 64 bit division (& built it for riscv32!)
- added a check to make sure we don't try to sleep for 0 us

Changes since v7:
- rebased on 6.0-rc1
- reworded comments you highlighted in v7
- fixed the overkill sleeping
- removed the unused variables in calc_duty
- added some extra comments to explain behaviours you questioned in v7
- make the mutexes un-interruptible
- fixed added the 1s you suggested for the if(period_locked) logic
- added setup of the channel_enabled shadowing
- fixed the period reporting for the negedge == posedge case in
  get_state() I had to add the enabled check, as otherwise it broke
  setting the period for the first time out of reset.
- added a test for invalid PERIOD_STEPS values, in which case we abort
  if we cannot fix the period

Changes from v6:
- Dropped an unused variable that I'd missed
- Actually check the return values of the mutex lock()s
- Re-rebased on -next for the MAINTAINERS patch (again...)

Changes from v5:
- switched to a mutex b/c we must sleep with the lock taken
- simplified the locking in apply() and added locking to get_state()
- reworked apply() as requested
- removed the loop in the period calculation (thanks Uwe!)
- add a copy of the enable registers in the driver to save on reads.
- remove the second (useless) write to sync_update
- added some missing rounding in get_state()
- couple other minor cleanups as requested in:
https://lore.kernel.org/linux-riscv/20220709160206.cw5luo7kxdshoiua@xxxxxxxxxxxxxx/

Changes from v4:
- dropped some accidentally added files

Conor Dooley (4):
  dt-bindings: pwm: fix microchip corePWM's pwm-cells
  riscv: dts: fix the icicle's #pwm-cells
  pwm: add microchip soft ip corePWM driver
  MAINTAINERS: add pwm to PolarFire SoC entry

 .../bindings/pwm/microchip,corepwm.yaml       |   4 +-
 MAINTAINERS                                   |   1 +
 .../dts/microchip/mpfs-icicle-kit-fabric.dtsi |   2 +-
 drivers/pwm/Kconfig                           |  10 +
 drivers/pwm/Makefile                          |   1 +
 drivers/pwm/pwm-microchip-core.c              | 397 ++++++++++++++++++
 6 files changed, 413 insertions(+), 2 deletions(-)
 create mode 100644 drivers/pwm/pwm-microchip-core.c

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2.37.3