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- 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 */
- };
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