StarFive's Pulse Width Modulation driver support

Hi,

This patchset adds initial rudimentary support for the StarFive Pulse Width Modulation controller driver. And this driver will be used in StarFive's VisionFive 2 board.The first patch add Documentations for the device and Patch 2 adds device probe for the module.

Changes v9->v10:
- Rebased to v6.7rc6.
- Dropped unuseful dependency.
- Added error handling.

Changes v8->v9:
- Rebased to v6.7rc4.
- Updated the bindings format.
- Dropped removed() interface.

Changes v7->v8:
- Rebased to v6.7rc3.
- Changed compatible to "opencores,pwm-v1"
- Adjusted the clock unprepare order.
- Followed dt-bindings Coding style.

Changes v6->v7:
- Rebased to v6.6.
- Added dependency architecture.
- Adopted new rounding algorithm.
- Added limitation descripton.
- Used function interfaces instead of macro definitions.
- Followed the linux coding style.

Changes v5->v6:
- Rebased to v6.6rc5.
- Changed driver into a generic OpenCores driver.
- Modified dt-bindings description into OpenCores.
- Uesd the StarFive compatible string to parameterize.

Changes v4->v5:
- Rebased to v6.6rc2.
- Updated macro definition indent.
- Replaced the clock initializes the interface.
- Fixed patch description.

Changes v3->v4:
- Rebased to v6.5rc7.
- Sorted the header files in alphabetic order.
- Changed iowrite32() to writel().
- Added a way to turn off.
- Modified polarity inversion implementation.
- Added 7100 support.
- Added dts patches.
- Used the various helpers in linux/math.h.
- Corrected formatting problems.
- Renamed dtbinding to 'starfive,jh7100-pwm.yaml'.
- Dropped the redundant code.

Changes v2->v3:
- Fixed some formatting issues.

Changes v1->v2:
- Renamed the dt-binding 'pwm-starfive.yaml' to 'starfive,jh7110-pwm.yaml'.
- Dropped the compatible's Items.
- Dropped the unuse defines.
- Modified the code to follow the Linux coding style.
- Changed return value to dev_err_probe.
- Dropped the unnecessary local variable.

The patch series is based on v6.7rc6.

William Qiu (4):
dt-bindings: pwm: Add bindings for OpenCores PWM Controller
pwm: opencores: Add PWM driver support
riscv: dts: starfive: jh7100: Add PWM node and pins configuration
riscv: dts: starfive: jh7110: Add PWM node and pins configuration

 .../bindings/pwm/opencores,pwm.yaml           |  55 +++++
 MAINTAINERS                                   |   7 +
 .../boot/dts/starfive/jh7100-common.dtsi      |  24 ++
 arch/riscv/boot/dts/starfive/jh7100.dtsi      |   9 +
 .../jh7110-starfive-visionfive-2.dtsi         |  22 ++
 arch/riscv/boot/dts/starfive/jh7110.dtsi      |   9 +
 drivers/pwm/Kconfig                           |  12 +
 drivers/pwm/Makefile                          |   1 +
 drivers/pwm/pwm-ocores.c                      | 233 ++++++++++++++++++
 9 files changed, 372 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/opencores,pwm.yaml
 create mode 100644 drivers/pwm/pwm-ocores.c

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2.34.1