[PATCH v8 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
a function. 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 V8:

- rebased on v7.3-rc1
- dropped the syscon. As a result, reintroduce the .remove
  callback
- dropped the reference to syscon in the bindings description
- Kconfig: the driver no longer depends on MFD_SYSCON
- added a new header file to export the function prototype to
  read the fan speed
- added the exported rp1_pwm_read_tachometer() function to
  obtain the RPM
- dropped a now unused local variable in the probe function
- link to v7: https://lore.kernel.org/all/cover.1784539788.git.andrea.porta@suse.com/


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                           |   8 +
 drivers/pwm/Makefile                          |   1 +
 drivers/pwm/pwm-rp1.c                         | 452 ++++++++++++++++++
 include/soc/bcm2835/raspberrypi-pwm-rp1.h     |  10 +
 7 files changed, 558 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/raspberrypi,rp1-pwm.yaml
 create mode 100644 drivers/pwm/pwm-rp1.c
 create mode 100644 include/soc/bcm2835/raspberrypi-pwm-rp1.h

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2.35.3