From: Hongwei Zhang <hongweiz@ami.com>
To: Joel Stanley <joel@jms.id.au>, Andrew Jeffery <andrew@aj.id.au>,
Linus Walleij <linus.walleij@linaro.org>,
<devicetree@vger.kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
linux-aspeed@lists.ozlabs.org, linux-gpio@vger.kernel.org,
linux-kernel@vger.kernel.org,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Rob Herring <robh+dt@kernel.org>,
Hongwei Zhang <hongweiz@ami.com>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/3 v4] dt-bindings: gpio: aspeed: Add SGPIO support
Date: Wed, 17 Jul 2019 16:12:05 -0400 [thread overview]
Message-ID: <1563394325-15941-1-git-send-email-hongweiz@ami.com> (raw)
Add bindings to support SGPIO on AST2400 or AST2500.
Signed-off-by: Hongwei Zhang <hongweiz@ami.com>
---
.../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@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
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next reply other threads:[~2019-07-17 20:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-17 20:12 Hongwei Zhang [this message]
2019-07-18 1:48 ` [PATCH 2/3 v4] dt-bindings: gpio: aspeed: Add SGPIO support Andrew Jeffery
2019-07-19 20:37 ` Hongwei Zhang
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