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Diffstat (limited to 'Documentation/devicetree/bindings/bus/ti-gpmc.txt')
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diff --git a/Documentation/devicetree/bindings/bus/ti-gpmc.txt b/Documentation/devicetree/bindings/bus/ti-gpmc.txt new file mode 100644 index 000000000000..5ddb2e9efaaa --- /dev/null +++ b/Documentation/devicetree/bindings/bus/ti-gpmc.txt @@ -0,0 +1,84 @@ +Device tree bindings for OMAP general purpose memory controllers (GPMC) + +The actual devices are instantiated from the child nodes of a GPMC node. + +Required properties: + + - compatible: Should be set to one of the following: + + ti,omap2420-gpmc (omap2420) + ti,omap2430-gpmc (omap2430) + ti,omap3430-gpmc (omap3430 & omap3630) + ti,omap4430-gpmc (omap4430 & omap4460 & omap543x) + ti,am3352-gpmc (am335x devices) + + - reg: A resource specifier for the register space + (see the example below) + - ti,hwmods: Should be set to "ti,gpmc" until the DT transition is + completed. + - #address-cells: Must be set to 2 to allow memory address translation + - #size-cells: Must be set to 1 to allow CS address passing + - gpmc,num-cs: The maximum number of chip-select lines that controller + can support. + - gpmc,num-waitpins: The maximum number of wait pins that controller can + support. + - ranges: Must be set up to reflect the memory layout with four + integer values for each chip-select line in use: + + <cs-number> 0 <physical address of mapping> <size> + + Currently, calculated values derived from the contents + of the per-CS register GPMC_CONFIG7 (as set up by the + bootloader) are used for the physical address decoding. + As this will change in the future, filling correct + values here is a requirement. + +Timing properties for child nodes. All are optional and default to 0. + + - gpmc,sync-clk: Minimum clock period for synchronous mode, in picoseconds + + Chip-select signal timings corresponding to GPMC_CONFIG2: + - gpmc,cs-on: Assertion time + - gpmc,cs-rd-off: Read deassertion time + - gpmc,cs-wr-off: Write deassertion time + + ADV signal timings corresponding to GPMC_CONFIG3: + - gpmc,adv-on: Assertion time + - gpmc,adv-rd-off: Read deassertion time + - gpmc,adv-wr-off: Write deassertion time + + WE signals timings corresponding to GPMC_CONFIG4: + - gpmc,we-on: Assertion time + - gpmc,we-off: Deassertion time + + OE signals timings corresponding to GPMC_CONFIG4: + - gpmc,oe-on: Assertion time + - gpmc,oe-off: Deassertion time + + Access time and cycle time timings corresponding to GPMC_CONFIG5: + - gpmc,page-burst-access: Multiple access word delay + - gpmc,access: Start-cycle to first data valid delay + - gpmc,rd-cycle: Total read cycle time + - gpmc,wr-cycle: Total write cycle time + +The following are only applicable to OMAP3+ and AM335x: + - gpmc,wr-access + - gpmc,wr-data-mux-bus + + +Example for an AM33xx board: + + gpmc: gpmc@50000000 { + compatible = "ti,am3352-gpmc"; + ti,hwmods = "gpmc"; + reg = <0x50000000 0x2000>; + interrupts = <100>; + + gpmc,num-cs = <8>; + gpmc,num-waitpins = <2>; + #address-cells = <2>; + #size-cells = <1>; + ranges = <0 0 0x08000000 0x10000000>; /* CS0 @addr 0x8000000, size 0x10000000 */ + + /* child nodes go here */ + }; |