Add support for the GPIO controller employed by Realtek in multiple series of MIPS SoCs. These include the supported RTL838x and RTL839x. The register layout also matches the one found in the GPIO controller of other (Lexra-based) SoCs such as RTL8196E, RTL8197D, and RTL8197F. For the platform name 'otto', I am not aware of any official resources as to what hardware this specifically applies to. However, in all of the GPL archives we've received, from vendors using compatible SoCs in their design, the platform under the MIPS architecture is referred to by this name. The GPIO ports have been tested on a Zyxel GS1900-8 (RTL8380), and Zyxel GS1900-48 (RTL8393). Furthermore, the GPIO ports and interrupt controller have been tested on a Netgear GS110TPPv1 (RTL8381). Changes in v4: - Fix pointer notation style - Drop unused read_u16_reg() function - Drop 'inline' specifier from functions Changes in v3: - Remove OF dependencies in driver probe - Don't accept IRQ_TYPE_NONE as a valid interrupt type - Remove (now unused) dev property from control structure - Use u8/u16 port registers, instead of raw u32 registers - Use 'line' name for gpiochip, 'port' and 'pin' names for hardware - Renamed DT bindings file - Dropped fallback-only DT compatible - Various code style clean-ups Changes in v2: - Clarify structure and usage of IMR registers - Added Linus' Reviewed-by tags Sander Vanheule (2): dt-bindings: gpio: Binding for Realtek Otto GPIO gpio: Add Realtek Otto GPIO support .../bindings/gpio/realtek,otto-gpio.yaml | 78 +++++ drivers/gpio/Kconfig | 11 + drivers/gpio/Makefile | 1 + drivers/gpio/gpio-realtek-otto.c | 330 ++++++++++++++++++ 4 files changed, 420 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/realtek,otto-gpio.yaml create mode 100644 drivers/gpio/gpio-realtek-otto.c -- 2.30.2