From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hongwei Zhang Date: Wed, 17 Jul 2019 16:12:05 -0400 Subject: [PATCH 2/3 v4] dt-bindings: gpio: aspeed: Add SGPIO support Message-ID: <1563394325-15941-1-git-send-email-hongweiz@ami.com> List-Id: To: linux-aspeed@lists.ozlabs.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Add bindings to support SGPIO on AST2400 or AST2500. Signed-off-by: Hongwei Zhang --- .../devicetree/bindings/gpio/sgpio-aspeed.txt | 55 ++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt diff --git a/Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt b/Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt new file mode 100644 index 0000000..2d6305e --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt @@ -0,0 +1,55 @@ +Aspeed SGPIO controller Device Tree Bindings +------------------------------------------- + +This SGPIO controller is for ASPEED AST2500 SoC, it supports up to 80 full +featured Serial GPIOs. Each of the Serial GPIO pins can be programmed to +support the following options: +- Support interrupt option for each input port and various interrupt + sensitivity option (level-high, level-low, edge-high, edge-low) +- Support reset tolerance option for each output port +- Directly connected to APB bus and its shift clock is from APB bus clock + divided by a programmable value. +- Co-work with external signal-chained TTL components (74LV165/74LV595) + + +Required properties: + +- compatible : Either "aspeed,ast2400-sgpio" or "aspeed,ast2500-sgpio" + +- #gpio-cells : Should be two + - First cell is the GPIO line number + - Second cell is used to specify optional + parameters (unused) + +- reg : Address and length of the register set for the device +- gpio-controller : Marks the device node as a GPIO controller +- interrupts : Interrupt specifier (see interrupt bindings for + details) + +- interrupt-controller : Mark the GPIO controller as an interrupt-controller + +- nr-gpios : number of GPIO pins to serialise. + (should be multiple of 8, up to 80 pins) + +- clocks : A phandle to the APB clock for SGPM clock division + +- bus-frequency : SGPM CLK frequency + + +The sgpio and interrupt properties are further described in their respective bindings documentation: + +- Documentation/devicetree/bindings/sgpio/gpio.txt +- Documentation/devicetree/bindings/interrupt-controller/interrupts.txt + + Example: + sgpio: sgpio at 1e780200 { + #gpio-cells = <2>; + compatible = "aspeed,ast2500-sgpio"; + gpio-controller; + interrupts = <40>; + reg = <0x1e780200 0x0100>; + clocks = <&syscon ASPEED_CLK_APB>; + interrupt-controller; + nr-gpios = <8>; + bus-frequency = <12000000>; + }; -- 2.7.4