[PATCH v6 0/3] Add RP1 PWM controller support

[Andrea della Porta]

This patchset adds support for the PWM controller found on the
Raspberry Pi RP1 southbridge. This is necessary to operate the
cooling fan connected to one of the PWM channels.

The tachometer pin for the fan speed is managed by the firmware 
running on the RP1's M-core. It uses the PHASE2 register
to report the RPM, which is then exported by this driver via
syscon registers. A subsequent patch will add a new device
and driver to read the RPM and export this value via hwmon.
 
Subsequent patches will also add the CPU thermal zone, which
acts as a consumer of the PWM device.

Best regards,
Andrea

CHANGES in V6:

- dt-bindings: added Andrea and Stanimir as maintiners, Naushir if
  you want to be dropped from the maintainer list, please just give
  me a shout
- dt-bindings: added dmas properties in case the driver will support
  that in the future
- _tohw(): fetch the actual polarity in the disable case to avoid
  potential glitch due to garbage data in the passed-in param
- _tohw(): fixed a compilation error on 32 bit target due to missing
  64 bit divider helper function
- _fromhw(): division by clk_rate explicitly cast to 32 bit for the
  divisor
- _fromhw(): fixed an unsigned underflow in ticks calculation
- set the atomic flag to allow calling from atomic context


Naushir Patuck (2):
  dt-bindings: pwm: Add Raspberry Pi RP1 PWM controller
  pwm: rp1: Add RP1 PWM controller driver

Stanimir Varbanov (1):
  arm64: dts: broadcom: rpi-5: Add RP1 PWM node

 .../bindings/pwm/raspberrypi,rp1-pwm.yaml     |  66 +++
 .../boot/dts/broadcom/bcm2712-rpi-5-b.dts     |  12 +
 arch/arm64/boot/dts/broadcom/rp1-common.dtsi  |   9 +
 drivers/pwm/Kconfig                           |   9 +
 drivers/pwm/Makefile                          |   1 +
 drivers/pwm/pwm-rp1.c                         | 435 ++++++++++++++++++
 6 files changed, 532 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/raspberrypi,rp1-pwm.yaml
 create mode 100644 drivers/pwm/pwm-rp1.c

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2.35.3