The Kontron sl28cpld is a board management chip providing gpio, pwm, fan monitoring and an interrupt controller. For now this controller is used on the Kontron SMARC-sAL28 board. But because of its flexible nature, it might also be used on other boards in the future. The individual blocks (like gpio, pwm, etc) are kept intentionally small. The MFD core driver then instantiates different (or multiple of the same) blocks. It also provides the register layout so it might be updated in the future without a device tree change; and support other boards with a different layout or functionalities. See also [1] for more information. There is one problem though: Documentation/devicetree/bindings/mfd/kontron,sl28cpld.example.dts:32.24-41.19: Warning (unique_unit_address): /example-0/i2c/sl28cpld@4a/gpio@0: duplicate unit-address (also used in node /example-0/i2c/sl28cpld@4a/pwm@0) Documentation/devicetree/bindings/mfd/kontron,sl28cpld.example.dts:43.24-52.19: Warning (unique_unit_address): /example-0/i2c/sl28cpld@4a/gpio@1: duplicate unit-address (also used in node /example-0/i2c/sl28cpld@4a/pwm@1) This is because the reg property is used to match multiple MFD cells which has the same devicetree compatible string. See patch 3. So only the (reg, compatible string) is unique. Maybe I should use a different property but reg? This is my first take of a MFD driver. I don't know wether the subsystem maintainers should only be CCed on the patches which affect the subsystem or on all patches for this series. I've chosen the latter so you can get a more complete picture. [1] https://lore.kernel.org/linux-devicetree/0e3e8204ab992d75aa07fc36af7e4ab2@xxxxxxxx/ Michael Walle (18): include/linux/ioport.h: add helper to define REG resource constructs mfd: mfd-core: Don't overwrite the dma_mask of the child device mfd: mfd-core: match device tree node against reg property dt-bindings: mfd: Add bindings for sl28cpld mfd: Add support for Kontron sl28cpld management controller irqchip: add sl28cpld interrupt controller support dt-bindings: watchdog: Add bindings for sl28cpld watchdog watchdog: add support for sl28cpld watchdog dt-bindings: pwm: Add bindings for sl28cpld PWM controller pwm: add support for sl28cpld PWM controller dt-bindings: gpio: Add bindings for sl28cpld GPIO controller gpio: add support for the sl28cpld GPIO controller dt-bindings: hwmon: Add bindings for sl28cpld hardware monitoring hwmon: add support for the sl28cpld hardware monitoring controller arm64: dts: freescale: sl28: enable sl28cpld arm64: dts: freescale: sl28: map GPIOs to input events arm64: dts: freescale: sl28: enable LED support arm64: dts: freescale: sl28: enable fan support .../bindings/gpio/kontron,sl28cpld-gpio.yaml | 52 +++ .../hwmon/kontron,sl28cpld-hwmon.yaml | 28 ++ .../bindings/mfd/kontron,sl28cpld.yaml | 146 ++++++++ .../bindings/pwm/kontron,sl28cpld-pwm.yaml | 33 ++ .../watchdog/kontron,sl28cpld-wdt.yaml | 30 ++ .../fsl-ls1028a-kontron-kbox-a-230-ls.dts | 14 + .../fsl-ls1028a-kontron-sl28-var3-ads2.dts | 9 + .../freescale/fsl-ls1028a-kontron-sl28.dts | 119 +++++++ drivers/gpio/Kconfig | 11 + drivers/gpio/Makefile | 1 + drivers/gpio/gpio-sl28cpld.c | 332 ++++++++++++++++++ drivers/hwmon/Kconfig | 10 + drivers/hwmon/Makefile | 1 + drivers/hwmon/sl28cpld-hwmon.c | 146 ++++++++ drivers/irqchip/Kconfig | 3 + drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-sl28cpld.c | 92 +++++ drivers/mfd/Kconfig | 21 ++ drivers/mfd/Makefile | 2 + drivers/mfd/mfd-core.c | 28 +- drivers/mfd/sl28cpld.c | 155 ++++++++ drivers/pwm/Kconfig | 10 + drivers/pwm/Makefile | 1 + drivers/pwm/pwm-sl28cpld.c | 192 ++++++++++ drivers/watchdog/Kconfig | 11 + drivers/watchdog/Makefile | 1 + drivers/watchdog/sl28cpld_wdt.c | 238 +++++++++++++ include/linux/ioport.h | 5 + 28 files changed, 1682 insertions(+), 10 deletions(-) create mode 100644 Documentation/devicetree/bindings/gpio/kontron,sl28cpld-gpio.yaml create mode 100644 Documentation/devicetree/bindings/hwmon/kontron,sl28cpld-hwmon.yaml create mode 100644 Documentation/devicetree/bindings/mfd/kontron,sl28cpld.yaml create mode 100644 Documentation/devicetree/bindings/pwm/kontron,sl28cpld-pwm.yaml create mode 100644 Documentation/devicetree/bindings/watchdog/kontron,sl28cpld-wdt.yaml create mode 100644 drivers/gpio/gpio-sl28cpld.c create mode 100644 drivers/hwmon/sl28cpld-hwmon.c create mode 100644 drivers/irqchip/irq-sl28cpld.c create mode 100644 drivers/mfd/sl28cpld.c create mode 100644 drivers/pwm/pwm-sl28cpld.c create mode 100644 drivers/watchdog/sl28cpld_wdt.c -- 2.20.1