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Diffstat (limited to 'Documentation/devicetree/bindings/memory-controllers/ingenic,jz4780-nemc.txt')
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diff --git a/Documentation/devicetree/bindings/memory-controllers/ingenic,jz4780-nemc.txt b/Documentation/devicetree/bindings/memory-controllers/ingenic,jz4780-nemc.txt new file mode 100644 index 000000000000..f936b5589b19 --- /dev/null +++ b/Documentation/devicetree/bindings/memory-controllers/ingenic,jz4780-nemc.txt @@ -0,0 +1,75 @@ +* Ingenic JZ4780 NAND/external memory controller (NEMC) + +This file documents the device tree bindings for the NEMC external memory +controller in Ingenic JZ4780 + +Required properties: +- compatible: Should be set to one of: + "ingenic,jz4780-nemc" (JZ4780) +- reg: Should specify the NEMC controller registers location and length. +- clocks: Clock for the NEMC controller. +- #address-cells: Must be set to 2. +- #size-cells: Must be set to 1. +- ranges: A set of ranges for each bank describing the physical memory layout. + Each should specify the following 4 integer values: + + <cs number> 0 <physical address of mapping> <size of mapping> + +Each child of the NEMC node describes a device connected to the NEMC. + +Required child node properties: +- reg: Should contain at least one register specifier, given in the following + format: + + <cs number> <offset> <size> + + Multiple registers can be specified across multiple banks. This is needed, + for example, for packaged NAND devices with multiple dies. Such devices + should be grouped into a single node. + +Optional child node properties: +- ingenic,nemc-bus-width: Specifies the bus width in bits. Defaults to 8 bits. +- ingenic,nemc-tAS: Address setup time in nanoseconds. +- ingenic,nemc-tAH: Address hold time in nanoseconds. +- ingenic,nemc-tBP: Burst pitch time in nanoseconds. +- ingenic,nemc-tAW: Access wait time in nanoseconds. +- ingenic,nemc-tSTRV: Static memory recovery time in nanoseconds. + +If a child node references multiple banks in its "reg" property, the same value +for all optional parameters will be configured for all banks. If any optional +parameters are omitted, they will be left unchanged from whatever they are +configured to when the NEMC device is probed (which may be the reset value as +given in the hardware reference manual, or a value configured by the boot +loader). + +Example (NEMC node with a NAND child device attached at CS1): + +nemc: nemc@13410000 { + compatible = "ingenic,jz4780-nemc"; + reg = <0x13410000 0x10000>; + + #address-cells = <2>; + #size-cells = <1>; + + ranges = <1 0 0x1b000000 0x1000000 + 2 0 0x1a000000 0x1000000 + 3 0 0x19000000 0x1000000 + 4 0 0x18000000 0x1000000 + 5 0 0x17000000 0x1000000 + 6 0 0x16000000 0x1000000>; + + clocks = <&cgu JZ4780_CLK_NEMC>; + + nand: nand@1 { + compatible = "ingenic,jz4780-nand"; + reg = <1 0 0x1000000>; + + ingenic,nemc-tAS = <10>; + ingenic,nemc-tAH = <5>; + ingenic,nemc-tBP = <10>; + ingenic,nemc-tAW = <15>; + ingenic,nemc-tSTRV = <100>; + + ... + }; +}; |