From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934086AbcECQk0 (ORCPT ); Tue, 3 May 2016 12:40:26 -0400 Received: from mail.kernel.org ([198.145.29.136]:41061 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933463AbcECQkZ (ORCPT ); Tue, 3 May 2016 12:40:25 -0400 Date: Tue, 3 May 2016 11:40:19 -0500 From: Rob Herring To: Boris Brezillon Cc: Nicolas Ferre , Jean-Christophe Plagniol-Villard , Alexandre Belloni , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Arnd Bergmann , Jean-Jacques Hiblot Subject: Re: [PATCH v7 2/2] memory: atmel-ebi: add DT bindings documentation Message-ID: <20160503164019.GA1604@rob-hp-laptop> References: <1461845007-23139-1-git-send-email-boris.brezillon@free-electrons.com> <1461845007-23139-2-git-send-email-boris.brezillon@free-electrons.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1461845007-23139-2-git-send-email-boris.brezillon@free-electrons.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 28, 2016 at 02:03:27PM +0200, Boris Brezillon wrote: > The EBI (External Bus Interface) is used to access external peripherals > (NOR, SRAM, NAND, and other specific devices like ethernet controllers). > Each device is assigned a CS line and an address range and can have its > own configuration (timings, access mode, bus width, ...). > This driver provides a generic DT binding to configure a device according > to its requirements. > For specific device controllers (like the NAND one) the SMC timings > should be configured by the controller driver through the matrix and smc > syscon regmaps. > > Signed-off-by: Boris Brezillon > --- > .../bindings/memory-controllers/atmel,ebi.txt | 136 +++++++++++++++++++++ > 1 file changed, 136 insertions(+) > create mode 100644 Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt > > diff --git a/Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt b/Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt > new file mode 100644 > index 0000000..a6dca5c > --- /dev/null > +++ b/Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt > @@ -0,0 +1,136 @@ > +* Device tree bindings for Atmel EBI > + > +The External Bus Interface (EBI) controller is a bus where you can connect > +asynchronous (NAND, NOR, SRAM, ....) and synchronous memories (SDR/DDR SDRAMs). > +The EBI provides a glue-less interface to asynchronous memories through the SMC > +(Static Memory Controller). > + > +Required properties: > + > +- compatible: "atmel,at91sam9260-ebi" > + "atmel,at91sam9261-ebi" > + "atmel,at91sam9263-ebi0" > + "atmel,at91sam9263-ebi1" What are the differences between 0 and 1? > + "atmel,at91sam9rl-ebi" > + "atmel,at91sam9g45-ebi" > + "atmel,at91sam9x5-ebi" > + "atmel,sama5d3-ebi" > + > +- reg: Contains offset/length value for EBI memory mapping. > + This property might contain several entries if the EBI > + memory range is not contiguous > + > +- #address-cells: Must be 2. > + The first cell encodes the CS. > + The second cell encode the offset into the CS memory > + range. > + > +- #size-cells: Must be set to 1. > + > +- ranges: Encodes CS to memory region association. > + > +- clocks: Clock feeding the EBI controller. > + See clock-bindings.txt > + > +Children device nodes are representing device connected to the EBI bus. > + > +Required device node properties: > + > +- #reg: Contains the chip-select id, the offset and the length s/#reg/reg/ > + of the memory region requested by the device. > + > +EBI bus configuration associated with specific chip-select will be defined in > +the configs subnode. This configs node will in turn contain several subnodes > +named config-, each of them containing the following properties. This is a bit unusual. Why not just part of the child device nodes? > + > +Optional config- node properties: > + > +- atmel,bus-width: width of the asynchronous device's data bus > + 8, 16 or 32. > + Default to 8 when undefined. > + > +- atmel,byte-access-type "write" or "select" (see Atmel datasheet). > + Default to "select" when undefined. > + > +- atmel,read-mode "nrd" or "ncs". > + Default to "ncs" when undefined. > + > +- atmel,write-mode "nwe" or "ncs". > + Default to "ncs" when undefined. > + > +- atmel,exnw-mode "disabled", "frozen" or "ready". > + Default to "disabled" when undefined. > + > +- atmel,page-mode enable page mode if present. The provided value > + defines the page size (supported values: 4, 8, > + 16 and 32). > + > +- atmel,tdf-mode: "normal" or "optimized". When set to This should be boolean. > + "optimized" the data float time is optimized > + depending on the next device being accessed > + (next device setup time is subtracted to the > + current device data float time). > + Default to "normal" when undefined. > + > +Mandatory timings expressed in nanoseconds (see Atmel datasheet for a full > +description). Required first, then optional properties please. > + > +- atmel,ncs-rd-setup-ns > +- atmel,nrd-setup-ns > +- atmel,ncs-wr-setup-ns > +- atmel,nwe-setup-ns > +- atmel,ncs-rd-pulse-ns > +- atmel,nrd-pulse-ns > +- atmel,ncs-wr-pulse-ns > +- atmel,nwe-pulse-ns > +- atmel,nwe-cycle-ns > +- atmel,nrd-cycle-ns > +- atmel,tdf-ns > + > +Example: > + > + ebi: ebi@10000000 { > + compatible = "atmel,sama5d3-ebi"; > + #address-cells = <2>; > + #size-cells = <1>; > + atmel,smc = <&hsmc>; > + atmel,matrix = <&matrix>; What are these? > + reg = <0x10000000 0x10000000 > + 0x40000000 0x30000000>; > + ranges = <0x0 0x0 0x10000000 0x10000000 > + 0x1 0x0 0x40000000 0x10000000 > + 0x2 0x0 0x50000000 0x10000000 > + 0x3 0x0 0x60000000 0x10000000>; > + clocks = <&mck>; > + > + pinctrl-names = "default"; > + pinctrl-0 = <&pinctrl_ebi_addr>; Not documented. > + > + configs { > + config-0 { > + atmel,read-mode = "nrd"; > + atmel,write-mode = "nwe"; > + atmel,bus-width = <16>; > + atmel,ncs-rd-setup-ns = <0>; > + atmel,ncs-wr-setup-ns = <0>; > + atmel,nwe-setup-ns = <8>; > + atmel,nrd-setup-ns = <16>; > + atmel,ncs-rd-pulse-ns = <84>; > + atmel,ncs-wr-pulse-ns = <84>; > + atmel,nrd-pulse-ns = <76>; > + atmel,nwe-pulse-ns = <76>; > + atmel,nrd-cycle-ns = <107>; > + atmel,nwe-cycle-ns = <84>; > + atmel,tdf-ns = <16>; > + }; > + }; > + > + nor: flash@0,0 { > + compatible = "cfi-flash"; > + #address-cells = <1>; > + #size-cells = <1>; > + reg = <0x0 0x0 0x1000000>; > + bank-width = <2>; > + }; > + }; > + > -- > 2.7.4 >