Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751988AbaLCPiI (ORCPT ); Wed, 3 Dec 2014 10:38:08 -0500 Received: from down.free-electrons.com ([37.187.137.238]:41319 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751884AbaLCPiG convert rfc822-to-8bit (ORCPT ); Wed, 3 Dec 2014 10:38:06 -0500 Date: Wed, 3 Dec 2014 16:38:02 +0100 From: Boris Brezillon To: Boris Brezillon Cc: Nicolas Ferre , "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: <20141203163802.2a9c7610@bbrezillon> In-Reply-To: <20141203163449.3ca4f43b@bbrezillon> 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> <20141203163449.3ca4f43b@bbrezillon> 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 Sorry for the noise, I sent the email before finishing my answer. On Wed, 3 Dec 2014 16:34:49 +0100 Boris Brezillon wrote: > 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: • EBI_CS4A: EBI Chip Select 4 Assignment 0 = EBI Chip Select 4 is only assigned to the Static Memory Controller and EBI_NCS4 behaves as defined by the SMC. 1 = EBI Chip Select 4 is assigned to the Static Memory Controller and the CompactFlash Logic (first slot) is activated. What about using "atmel,generic-logic" instead of "atmel,generic-dev" ? -- 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/