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    SubjectRe: [PATCH v3 06/11] memory: atmel-ebi: add DT bindings documentation
    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 <boris.brezillon@free-electrons.com>
    >> ---
    >> .../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.

    >> + 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


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