diff options
Diffstat (limited to 'Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt | 136 |
1 files changed, 136 insertions, 0 deletions
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 000000000..9bb5f57e2 --- /dev/null +++ b/Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt @@ -0,0 +1,136 @@ +* 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 through the SMC +(Static Memory Controller). + +Required properties: + +- compatible: "atmel,at91sam9260-ebi" + "atmel,at91sam9261-ebi" + "atmel,at91sam9263-ebi0" + "atmel,at91sam9263-ebi1" + "atmel,at91sam9rl-ebi" + "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 + +Children device nodes are representing device connected to the EBI bus. + +Required device node properties: + +- reg: Contains the chip-select id, the offset and the length + of the memory region requested by the device. + +EBI bus configuration will be defined directly in the device subnode. + +Optional EBI/SMC properties: + +- atmel,smc-bus-width: width of the asynchronous device's data bus + 8, 16 or 32. + Default to 8 when undefined. + +- atmel,smc-byte-access-type "write" or "select" (see Atmel datasheet). + Default to "select" when undefined. + +- atmel,smc-read-mode "nrd" or "ncs". + Default to "ncs" when undefined. + +- atmel,smc-write-mode "nwe" or "ncs". + Default to "ncs" when undefined. + +- atmel,smc-exnw-mode "disabled", "frozen" or "ready". + Default to "disabled" when undefined. + +- atmel,smc-page-mode enable page mode if present. The provided value + defines the page size (supported values: 4, 8, + 16 and 32). + +- atmel,smc-tdf-mode: "normal" or "optimized". When set to + "optimized" the data float time is optimized + depending on the next device being accessed + (next device setup time is subtracted to the + current device data float time). + Default to "normal" when undefined. + +If at least one atmel,smc- property is defined the following SMC timing +properties become mandatory. In the other hand, if none of the atmel,smc- +properties are specified, we assume that the EBI bus configuration will be +handled by the sub-device driver, and none of those properties should be +defined. + +All the timings are expressed in nanoseconds (see Atmel datasheet for a full +description). + +- atmel,smc-ncs-rd-setup-ns +- atmel,smc-nrd-setup-ns +- atmel,smc-ncs-wr-setup-ns +- atmel,smc-nwe-setup-ns +- atmel,smc-ncs-rd-pulse-ns +- atmel,smc-nrd-pulse-ns +- atmel,smc-ncs-wr-pulse-ns +- atmel,smc-nwe-pulse-ns +- atmel,smc-nwe-cycle-ns +- atmel,smc-nrd-cycle-ns +- atmel,smc-tdf-ns + +Example: + + ebi: ebi@10000000 { + compatible = "atmel,sama5d3-ebi"; + #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>; + + nor: flash@0,0 { + compatible = "cfi-flash"; + #address-cells = <1>; + #size-cells = <1>; + reg = <0x0 0x0 0x1000000>; + bank-width = <2>; + + atmel,smc-read-mode = "nrd"; + atmel,smc-write-mode = "nwe"; + atmel,smc-bus-width = <16>; + atmel,smc-ncs-rd-setup-ns = <0>; + atmel,smc-ncs-wr-setup-ns = <0>; + atmel,smc-nwe-setup-ns = <8>; + atmel,smc-nrd-setup-ns = <16>; + atmel,smc-ncs-rd-pulse-ns = <84>; + atmel,smc-ncs-wr-pulse-ns = <84>; + atmel,smc-nrd-pulse-ns = <76>; + atmel,smc-nwe-pulse-ns = <76>; + atmel,smc-nrd-cycle-ns = <107>; + atmel,smc-nwe-cycle-ns = <84>; + atmel,smc-tdf-ns = <16>; + }; + }; + |