Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt

Source file repositories/reference/linux-study-clean/Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt

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Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt
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Support Tooling And Documentation
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Support Tooling And Documentation: documentation
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Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

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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"
			"microchip,sam9x60-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.

Annotation

Implementation Notes