From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- Documentation/devicetree/bindings/mfd/cros-ec.txt | 65 +++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 Documentation/devicetree/bindings/mfd/cros-ec.txt (limited to 'Documentation/devicetree/bindings/mfd/cros-ec.txt') diff --git a/Documentation/devicetree/bindings/mfd/cros-ec.txt b/Documentation/devicetree/bindings/mfd/cros-ec.txt new file mode 100644 index 000000000..8009c3d87 --- /dev/null +++ b/Documentation/devicetree/bindings/mfd/cros-ec.txt @@ -0,0 +1,65 @@ +ChromeOS Embedded Controller + +Google's ChromeOS EC is a Cortex-M device which talks to the AP and +implements various function such as keyboard and battery charging. + +The EC can be connect through various means (I2C, SPI, LPC) and the +compatible string used depends on the interface. Each connection method has +its own driver which connects to the top level interface-agnostic EC driver. +Other Linux driver (such as cros-ec-keyb for the matrix keyboard) connect to +the top-level driver. + +Required properties (I2C): +- compatible: "google,cros-ec-i2c" +- reg: I2C slave address + +Required properties (SPI): +- compatible: "google,cros-ec-spi" +- reg: SPI chip select + +Optional properties (SPI): +- google,cros-ec-spi-msg-delay: Some implementations of the EC require some + additional processing time in order to accept new transactions. If the delay + between transactions is not long enough the EC may not be able to respond + properly to subsequent transactions and cause them to hang. This property + specifies the delay, in usecs, introduced between transactions to account + for the time required by the EC to get back into a state in which new data + can be accepted. + +Required properties (LPC): +- compatible: "google,cros-ec-lpc" +- reg: List of (IO address, size) pairs defining the interface uses + + +Example for I2C: + +i2c@12CA0000 { + cros-ec@1e { + reg = <0x1e>; + compatible = "google,cros-ec-i2c"; + interrupts = <14 0>; + interrupt-parent = <&wakeup_eint>; + wakeup-source; + }; + + +Example for SPI: + +spi@131b0000 { + ec@0 { + compatible = "google,cros-ec-spi"; + reg = <0x0>; + interrupts = <14 0>; + interrupt-parent = <&wakeup_eint>; + wakeup-source; + spi-max-frequency = <5000000>; + controller-data { + cs-gpio = <&gpf0 3 4 3 0>; + samsung,spi-cs; + samsung,spi-feedback-delay = <2>; + }; + }; +}; + + +Example for LPC is not supplied as it is not yet implemented. -- cgit v1.2.3-54-g00ecf