From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH v3 1/8] rsb: Add generic Reduced Serial Bus (RSB) controller binding documentation Date: Thu, 20 Aug 2015 17:08:45 +0200 Message-ID: <20150820150845.GB30520@lukather> References: <1439958009-14056-1-git-send-email-wens@csie.org> <1439958009-14056-2-git-send-email-wens@csie.org> Reply-To: maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="XoSOsMJQ8mz74oyx" Return-path: Content-Disposition: inline In-Reply-To: <1439958009-14056-2-git-send-email-wens-jdAy2FN1RRM@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Chen-Yu Tsai Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Greg Kroah-Hartman , Mark Brown , 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 List-Id: devicetree@vger.kernel.org --XoSOsMJQ8mz74oyx Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Hi, Thanks a lot for working on this. On Wed, Aug 19, 2015 at 12:20:02PM +0800, Chen-Yu Tsai wrote: > 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. What is the default if not set? > + > +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. I'd expect to have the hardware address first, but maybe it's just me :) > +Example: > + > + rsb@... { > + compatible = "..."; > + reg = <...>; > + /* ... */ > + #address-cells = <2>; > + #size-cells = <0>; > + > + pmic@2d { The unit-address should be 2d,3e3. > + compatible = "..."; > + reg = <0x2d 0x3e3>; > + > + /* ... */ > + }; > + }; > -- > 2.5.0 > -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --XoSOsMJQ8mz74oyx--