Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752178AbaLCPe4 (ORCPT ); Wed, 3 Dec 2014 10:34:56 -0500 Received: from down.free-electrons.com ([37.187.137.238]:41283 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751370AbaLCPex convert rfc822-to-8bit (ORCPT ); Wed, 3 Dec 2014 10:34:53 -0500 Date: Wed, 3 Dec 2014 16:34:49 +0100 From: Boris Brezillon To: Nicolas Ferre Cc: "Jean-Christophe Plagniol-Villard" , Alexandre Belloni , Andrew Victor , Samuel Ortiz , Lee Jones , 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 Message-ID: <20141203163449.3ca4f43b@bbrezillon> In-Reply-To: <547F2918.3070803@atmel.com> References: <1417429647-3419-1-git-send-email-boris.brezillon@free-electrons.com> <1417429647-3419-7-git-send-email-boris.brezillon@free-electrons.com> <547F24B6.8070504@atmel.com> <547F2918.3070803@atmel.com> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 3 Dec 2014 16:15:36 +0100 Nicolas Ferre wrote: > Le 03/12/2014 15:56, Nicolas Ferre a écrit : > > Le 01/12/2014 11:27, Boris Brezillon a écrit : > >> 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. > > Well... no real information, specify right here what a "generic device" is. I do not describe what a generic device is, but the description of a specialized device is given just below. Maybe I haven't chosen the appropriate word here. The datasheet gives the following description: > > >> + 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>; > >> + }; > >> + }; > >> + }; > >> + > >> > > > > > > -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- 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/