From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chen-Yu Tsai Subject: [PATCH v3 1/8] rsb: Add generic Reduced Serial Bus (RSB) controller binding documentation Date: Wed, 19 Aug 2015 12:20:02 +0800 Message-ID: <1439958009-14056-2-git-send-email-wens@csie.org> References: <1439958009-14056-1-git-send-email-wens@csie.org> Reply-To: wens-jdAy2FN1RRM@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <1439958009-14056-1-git-send-email-wens-jdAy2FN1RRM@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Maxime Ripard , Greg Kroah-Hartman , Mark Brown Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Hans de Goede , Meng Zhang , shuge-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org, kevin.z.m.zh-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Chen-Yu Tsai List-Id: devicetree@vger.kernel.org Reduced Serial Bus is a proprietary 2-line push-pull serial bus supporting multiple slave devices. It was developed by Allwinner, Inc. and used by Allwinner and X-Powers, Inc. for their line of PMICs and other peripheral ICs. Signed-off-by: Chen-Yu Tsai --- Documentation/devicetree/bindings/rsb/rsb.txt | 50 +++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 Documentation/devicetree/bindings/rsb/rsb.txt diff --git a/Documentation/devicetree/bindings/rsb/rsb.txt b/Documentation/devicetree/bindings/rsb/rsb.txt new file mode 100644 index 000000000000..0b027948ca9c --- /dev/null +++ b/Documentation/devicetree/bindings/rsb/rsb.txt @@ -0,0 +1,50 @@ +Reduced Serial Bus (RSB) Controller + +This document defines a generic set of bindings for use by RSB controllers. +A controller is modelled in device tree as a node with zero or more child +nodes, each representing a unique slave device on the bus. + +Required properties: + + - #address-cells : must be 2 + - #size-cells : must be 0 + +Optional properties: + + - clock-frequency : Desired bus clock frequency in Hz. Maximum is 20 MHz. + +Child nodes: + +An RSB controller node can contain zero or more child nodes representing +slave devices on the bus. Child 'reg' properties are specified as a +runtime address, hardware address pair. The hardware address is hardwired +in the device, which can normally be found in the datasheet. The runtime +address is set by software. No 2 devices on the same bus shall have the +same runtime address. + +Valid runtime addresses - There are only 15 valid runtime addresses: + + 0x17, 0x2d, 0x3a, 0x4e, 0x59, 0x63, 0x74, 0x8b, + 0x9c, 0xa6, 0xb1, 0xc5, 0xd2, 0xe8, 0xff + +It is highly recommended that one choose the same runtime addresses as +vendor BSPs use so that a) the addresses remain the same across different +software systems, and b) addresses of supported and listed slave devices +don't conflict with unsupported or not yet listed devices. + +Example: + + rsb@... { + compatible = "..."; + reg = <...>; + /* ... */ + #address-cells = <2>; + #size-cells = <0>; + + pmic@2d { + compatible = "..."; + reg = <0x2d 0x3e3>; + + /* ... */ + }; + }; -- 2.5.0