Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751714AbaLCO5A (ORCPT ); Wed, 3 Dec 2014 09:57:00 -0500 Received: from eusmtp01.atmel.com ([212.144.249.243]:17982 "EHLO eusmtp01.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751301AbaLCO46 (ORCPT ); Wed, 3 Dec 2014 09:56:58 -0500 Message-ID: <547F24B6.8070504@atmel.com> Date: Wed, 3 Dec 2014 15:56:54 +0100 From: Nicolas Ferre Organization: atmel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Boris Brezillon , "Jean-Christophe Plagniol-Villard" , Alexandre Belloni , Andrew Victor , Samuel Ortiz , Lee Jones CC: Rob Herring , Pawel Moll , "Mark Rutland" , Ian Campbell , Kumar Gala , , , , "Arnd Bergmann" , Jean-Jacques Hiblot Subject: Re: [PATCH v3 06/11] memory: atmel-ebi: add DT bindings documentation References: <1417429647-3419-1-git-send-email-boris.brezillon@free-electrons.com> <1417429647-3419-7-git-send-email-boris.brezillon@free-electrons.com> In-Reply-To: <1417429647-3419-7-git-send-email-boris.brezillon@free-electrons.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.161.30.18] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 01/12/2014 11:27, Boris Brezillon a ?crit : > 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 | 155 +++++++++++++++++++++ > 1 file changed, 155 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..3749ea1 > --- /dev/null > +++ b/Documentation/devicetree/bindings/memory-controllers/atmel-ebi.txt > @@ -0,0 +1,155 @@ > +* 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 though the SMC > +(Static Memory Controller). > +Synchronous memories (and some asynchronous memories like NANDs) can be > +attached to specialized controllers which are responsible for configuring the > +bus appropriately according to the connected device. > +In the other hand, the bus interface can be automated for simple asynchronous > +devices. > + > +Required properties: > + > +- compatible: "atmel,at91sam9260-ebi" > + "atmel,at91sam9261-ebi" > + "atmel,at91sam9263-ebi0" > + "atmel,at91sam9263-ebi1" Ditto: 9263 twice. > + "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 > + > +Child chip-select (cs) nodes contain the memory devices nodes connected to > +such as NOR (e.g. cfi-flash) and NAND. > +There might be board specific devices like FPGAs. > +You'll define you device requirements in these child nodes. > + > +Required child cs node properties: > + > +- #address-cells: Must be 2. > + > +- #size-cells: Must be 1. > + > +- ranges: Empty property indicating that child nodes can inherit > + memory layout. > + > +Optional child cs node properties: > +- atmel,generic-dev boolean property specifying if the device is > + a generic device. > + The following properties are only parsed if > + this property is present. > + Specialized devices are attached to specialized > + controllers which are responsible for > + configuring the bus appropriately. > + Here are some examples of specialized > + controllers: NAND, CompactFlash, SDR-SDRAM. > + > +- atmel,bus-width: width of the asynchronous device's data bus > + 8, 16 or 32. > + 8 if not present. > + > +- atmel,byte-access-type "write" or "select" (see Atmel datasheet). > + "select" if not present. > + > +- atmel,read-mode "nrd" or "ncs". > + "ncs" is not present. > + > +- atmel,write-mode "nwe" or "ncs". > + "ncs" is not present. > + > +- atmel,exnw-mode "disabled", "frozen" or "ready". > + "disabled" if not present. > + > +- atmel,page-mode enable page mode if present. The provided value > + defines the page size (supported values: 4, 8, > + 16 and 32). > + > +Optional device timings expressed in nanoseconds (if the property is not > +present 0 is assumed): > + > +- 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 > + > +- atmel,tdf-optimized data float optimized mode. If present the data > + float time is optimized depending on the next > + device being accessed (next device setup > + time is substracted to the current devive data Typo: subtract, device > + float time). > + > + > + > +Example: > + > + ebi: ebi@10000000 { > + compatible = "atmel,sama5d3-ebi", "simple-bus"; > + #address-cells = <2>; > + #size-cells = <1>; > + atmel,smc = <&hsmc>; > + atmel,matrix = <&matrix>; > + 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>; > + > + cs@0 { > + #address-cells = <2>; > + #size-cells = <1>; > + ranges; > + atmel,generic-dev; > + 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>; > + }; > + }; > + }; > + > -- Nicolas Ferre -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/