diff options
author | Hongwei Zhang <hongweiz@ami.com> | 2019-07-31 16:01:36 -0400 |
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committer | Linus Walleij <linus.walleij@linaro.org> | 2019-08-14 09:58:10 +0200 |
commit | 7a637fd32b234d4605fdf3c75c622b0ca1ce8cfb (patch) | |
tree | fa5b1b530aeeab6923032067fe0b8f3d3d2a549e /Documentation/devicetree/bindings | |
parent | b772d7aeae093a120c737c0183df532262229efe (diff) | |
download | linux-7a637fd32b234d4605fdf3c75c622b0ca1ce8cfb.tar.bz2 |
dt-bindings: gpio: aspeed: Add SGPIO support
Add bindings to support SGPIO on AST2400 or AST2500.
Signed-off-by: Hongwei Zhang <hongweiz@ami.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/1564603297-1391-2-git-send-email-hongweiz@ami.com
[Adjusted when applying in several ways]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/devicetree/bindings')
-rw-r--r-- | Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt b/Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt new file mode 100644 index 000000000000..d4d83916c09d --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/sgpio-aspeed.txt @@ -0,0 +1,45 @@ +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 : Should be one of + "aspeed,ast2400-sgpio", "aspeed,ast2500-sgpio" +- #gpio-cells : Should be 2, see gpio.txt +- 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-controller/interrupts.txt +- interrupt-controller : Mark the GPIO controller as an interrupt-controller +- ngpios : number of GPIO lines, see gpio.txt + (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/gpio/gpio.txt +- Documentation/devicetree/bindings/interrupt-controller/interrupts.txt + + Example: + sgpio: sgpio@1e780200 { + #gpio-cells = <2>; + compatible = "aspeed,ast2500-sgpio"; + gpio-controller; + interrupts = <40>; + reg = <0x1e780200 0x0100>; + clocks = <&syscon ASPEED_CLK_APB>; + interrupt-controller; + ngpios = <8>; + bus-frequency = <12000000>; + }; |