* Device tree bindings for Atmel EBI
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The External Bus Interface (EBI) controller is a bus where you can connect
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asynchronous (NAND, NOR, SRAM, ....) and synchronous memories (SDR/DDR SDRAMs).
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The EBI provides a glue-less interface to asynchronous memories through the SMC
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(Static Memory Controller).
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Required properties:
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- compatible: "atmel,at91sam9260-ebi"
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"atmel,at91sam9261-ebi"
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"atmel,at91sam9263-ebi0"
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"atmel,at91sam9263-ebi1"
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"atmel,at91sam9rl-ebi"
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"atmel,at91sam9g45-ebi"
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"atmel,at91sam9x5-ebi"
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"atmel,sama5d3-ebi"
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- reg: Contains offset/length value for EBI memory mapping.
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This property might contain several entries if the EBI
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memory range is not contiguous
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- #address-cells: Must be 2.
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The first cell encodes the CS.
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The second cell encode the offset into the CS memory
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range.
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- #size-cells: Must be set to 1.
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- ranges: Encodes CS to memory region association.
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- clocks: Clock feeding the EBI controller.
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See clock-bindings.txt
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Children device nodes are representing device connected to the EBI bus.
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Required device node properties:
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- reg: Contains the chip-select id, the offset and the length
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of the memory region requested by the device.
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EBI bus configuration will be defined directly in the device subnode.
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Optional EBI/SMC properties:
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- atmel,smc-bus-width: width of the asynchronous device's data bus
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8, 16 or 32.
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Default to 8 when undefined.
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- atmel,smc-byte-access-type "write" or "select" (see Atmel datasheet).
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Default to "select" when undefined.
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- atmel,smc-read-mode "nrd" or "ncs".
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Default to "ncs" when undefined.
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- atmel,smc-write-mode "nwe" or "ncs".
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Default to "ncs" when undefined.
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- atmel,smc-exnw-mode "disabled", "frozen" or "ready".
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Default to "disabled" when undefined.
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- atmel,smc-page-mode enable page mode if present. The provided value
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defines the page size (supported values: 4, 8,
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16 and 32).
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- atmel,smc-tdf-mode: "normal" or "optimized". When set to
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"optimized" the data float time is optimized
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depending on the next device being accessed
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(next device setup time is subtracted to the
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current device data float time).
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Default to "normal" when undefined.
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If at least one atmel,smc- property is defined the following SMC timing
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properties become mandatory. In the other hand, if none of the atmel,smc-
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properties are specified, we assume that the EBI bus configuration will be
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handled by the sub-device driver, and none of those properties should be
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defined.
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All the timings are expressed in nanoseconds (see Atmel datasheet for a full
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description).
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- atmel,smc-ncs-rd-setup-ns
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- atmel,smc-nrd-setup-ns
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- atmel,smc-ncs-wr-setup-ns
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- atmel,smc-nwe-setup-ns
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- atmel,smc-ncs-rd-pulse-ns
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- atmel,smc-nrd-pulse-ns
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- atmel,smc-ncs-wr-pulse-ns
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- atmel,smc-nwe-pulse-ns
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- atmel,smc-nwe-cycle-ns
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- atmel,smc-nrd-cycle-ns
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- atmel,smc-tdf-ns
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Example:
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ebi: ebi@10000000 {
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compatible = "atmel,sama5d3-ebi";
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#address-cells = <2>;
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#size-cells = <1>;
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atmel,smc = <&hsmc>;
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atmel,matrix = <&matrix>;
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reg = <0x10000000 0x10000000
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0x40000000 0x30000000>;
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ranges = <0x0 0x0 0x10000000 0x10000000
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0x1 0x0 0x40000000 0x10000000
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0x2 0x0 0x50000000 0x10000000
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0x3 0x0 0x60000000 0x10000000>;
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clocks = <&mck>;
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pinctrl-names = "default";
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pinctrl-0 = <&pinctrl_ebi_addr>;
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nor: flash@0,0 {
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compatible = "cfi-flash";
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#address-cells = <1>;
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#size-cells = <1>;
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reg = <0x0 0x0 0x1000000>;
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bank-width = <2>;
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atmel,smc-read-mode = "nrd";
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atmel,smc-write-mode = "nwe";
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atmel,smc-bus-width = <16>;
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atmel,smc-ncs-rd-setup-ns = <0>;
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atmel,smc-ncs-wr-setup-ns = <0>;
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atmel,smc-nwe-setup-ns = <8>;
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atmel,smc-nrd-setup-ns = <16>;
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atmel,smc-ncs-rd-pulse-ns = <84>;
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atmel,smc-ncs-wr-pulse-ns = <84>;
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atmel,smc-nrd-pulse-ns = <76>;
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atmel,smc-nwe-pulse-ns = <76>;
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atmel,smc-nrd-cycle-ns = <107>;
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atmel,smc-nwe-cycle-ns = <84>;
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atmel,smc-tdf-ns = <16>;
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};
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};
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