From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Ferre Subject: Re: [PATCH v3 06/11] memory: atmel-ebi: add DT bindings documentation Date: Wed, 3 Dec 2014 16:15:36 +0100 Message-ID: <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> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <547F24B6.8070504-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org 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 , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Arnd Bergmann , Jean-Jacques Hiblot List-Id: devicetree@vger.kernel.org Le 03/12/2014 15:56, Nicolas Ferre a =E9crit : > Le 01/12/2014 11:27, Boris Brezillon a =E9crit : >> The EBI (External Bus Interface) is used to access external peripher= als >> (NOR, SRAM, NAND, and other specific devices like ethernet controlle= rs). >> 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 acco= rding >> 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-control= lers/atmel-ebi.txt >> >> diff --git a/Documentation/devicetree/bindings/memory-controllers/at= mel-ebi.txt b/Documentation/devicetree/bindings/memory-controllers/atme= l-ebi.txt >> new file mode 100644 >> index 0000000..3749ea1 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/memory-controllers/atmel-ebi= =2Etxt >> @@ -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 tho= ugh the SMC >> +(Static Memory Controller). >> +Synchronous memories (and some asynchronous memories like NANDs) ca= n be >> +attached to specialized controllers which are responsible for confi= guring the >> +bus appropriately according to the connected device. >> +In the other hand, the bus interface can be automated for simple as= ynchronous >> +devices. >> + >> +Required properties: >> + >> +- compatible: "atmel,at91sam9260-ebi" >> + "atmel,at91sam9261-ebi" >> + "atmel,at91sam9263-ebi0" >> + "atmel,at91sam9263-ebi1" >=20 > Ditto: 9263 twice. >=20 >> + "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 conne= cted 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. >> + 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 i= s 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 da= ta >> + float time is optimized depending on the next >> + device being accessed (next device setup >> + time is substracted to the current devive data >=20 > Typo: subtract, device >=20 >> + float time). >> + >> + >> + >> +Example: >> + >> + ebi: ebi@10000000 { >> + compatible =3D "atmel,sama5d3-ebi", "simple-bus"; >> + #address-cells =3D <2>; >> + #size-cells =3D <1>; >> + atmel,smc =3D <&hsmc>; >> + atmel,matrix =3D <&matrix>; >> + reg =3D <0x10000000 0x10000000 >> + 0x40000000 0x30000000>; >> + ranges =3D <0x0 0x0 0x10000000 0x10000000 >> + 0x1 0x0 0x40000000 0x10000000 >> + 0x2 0x0 0x50000000 0x10000000 >> + 0x3 0x0 0x60000000 0x10000000>; >> + clocks =3D <&mck>; >> + >> + pinctrl-names =3D "default"; >> + pinctrl-0 =3D <&pinctrl_ebi_addr>; >> + >> + cs@0 { >> + #address-cells =3D <2>; >> + #size-cells =3D <1>; >> + ranges; >> + atmel,generic-dev; >> + atmel,read-mode =3D "nrd"; >> + atmel,write-mode =3D "nwe"; >> + atmel,bus-width =3D <16>; >> + atmel,ncs-rd-setup-ns =3D <0>; >> + atmel,ncs-wr-setup-ns =3D <0>; >> + atmel,nwe-setup-ns =3D <8>; >> + atmel,nrd-setup-ns =3D <16>; >> + atmel,ncs-rd-pulse-ns =3D <84>; >> + atmel,ncs-wr-pulse-ns =3D <84>; >> + atmel,nrd-pulse-ns =3D <76>; >> + atmel,nwe-pulse-ns =3D <76>; >> + atmel,nrd-cycle-ns =3D <107>; >> + atmel,nwe-cycle-ns =3D <84>; >> + atmel,tdf-ns =3D <16>; >> + >> + nor: flash@0,0 { >> + compatible =3D "cfi-flash"; >> + #address-cells =3D <1>; >> + #size-cells =3D <1>; >> + reg =3D <0x0 0x0 0x1000000>; >> + bank-width =3D <2>; >> + }; >> + }; >> + }; >> + >> >=20 >=20 --=20 Nicolas Ferre -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html