[PATCH v2 06/11] memory: atmel-ebi: add DT bindings documentation

Boris Brezillon boris.brezillon at free-electrons.com
Wed Nov 5 08:01:22 PST 2014


Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
---
 .../bindings/memory-controllers/atmel-ebi.txt      | 153 +++++++++++++++++++++
 1 file changed, 153 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/atmel-ebi.txt

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 0000000..dc2c34f
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/atmel-ebi.txt
@@ -0,0 +1,153 @@
+* 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 though the SMC
+(Static Memory Controller).
+Synchronous memories (and some asynchronous memories like NANDs) can be
+attached to specialized controllers which are responsible for configuring the
+bus appropriately according to the connected device.
+In the other hand, the bus interface can be automated for simple asynchronous
+devices.
+
+Required properties:
+
+- compatible:		"atmel,at91sam9260-ebi"
+			"atmel,at91sam9261-ebi"
+			"atmel,at91sam9263-ebi0"
+			"atmel,at91sam9263-ebi1"
+			"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
+
+Child chip-select (cs) nodes contain the memory devices nodes connected to
+such as NOR (e.g. cfi-flash) and NAND.
+There might be board specific devices like FPGAs.
+You'll define you device requirements in these child nodes.
+
+Required child cs node properties:
+
+- #address-cells:	Must be 2.
+
+- #size-cells:		Must be 1.
+
+- ranges:		Empty property indicating that child nodes can inherit
+			memory layout.
+
+Optional child cs node properties:
+- atmel,generic-dev		boolean property specifying if the device is
+				a generic device.
+				The following properties are only parsed if
+				this property is present.
+				Specialized devices are attached to specialized
+				controllers which should configure the bus
+				appropriately.
+
+- atmel,bus-width:		width of the asynchronous device's data bus
+				8, 16 or 32.
+				8 if not present.
+
+- atmel,byte-access-type	"write" or "select" (see Atmel datasheet).
+				"select" if not present.
+
+- atmel,read-mode		"nrd" or "ncs".
+				"ncs" is not present.
+
+- atmel,write-mode		"nwe" or "ncs".
+				"ncs" is not present.
+
+- atmel,exnw-mode		"disabled", "frozen" or "ready".
+				"disabled" if not present.
+
+- atmel,page-mode		enable page mode if present. The provided value
+				defines the page size (supported values: 4, 8,
+				16 and 32).
+
+Optional device timings expressed in nanoseconds (if the property is not
+present 0 is assumed):
+
+- atmel,ncs-rd-setup-ns
+- atmel,nrd-setup-ns
+- atmel,ncs-wr-setup-ns
+- atmel,nwe-setup-ns
+- atmel,ncs-rd-pulse-ns
+- atmel,nrd-pulse-ns
+- atmel,ncs-wr-pulse-ns
+- atmel,nwe-pulse-ns
+- atmel,nwe-cycle-ns
+- atmel,nrd-cycle-ns
+- atmel,tdf-ns
+
+- atmel,tdf-optimized		data float optimized mode. If present the data
+				float time is optimized depending on the next
+				device being accessed (next device setup
+				time is substracted to the current devive data
+				float time).
+
+
+
+Example:
+
+	ebi: ebi at 10000000 {
+		compatible = "atmel,sama5d3-ebi", "simple-bus";
+		#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>;
+
+		cs at 0 {
+			#address-cells = <2>;
+			#size-cells = <1>;
+			ranges;
+			atmel,generic-dev;
+			atmel,read-mode = "nrd";
+			atmel,write-mode = "nwe";
+			atmel,bus-width = <16>;
+			atmel,ncs-rd-setup-ns = <0>;
+			atmel,ncs-wr-setup-ns = <0>;
+			atmel,nwe-setup-ns = <8>;
+			atmel,nrd-setup-ns = <16>;
+			atmel,ncs-rd-pulse-ns = <84>;
+			atmel,ncs-wr-pulse-ns = <84>;
+			atmel,nrd-pulse-ns = <76>;
+			atmel,nwe-pulse-ns = <76>;
+			atmel,nrd-cycle-ns = <107>;
+			atmel,nwe-cycle-ns = <84>;
+			atmel,tdf-ns = <16>;
+
+			nor: flash at 0,0 {
+				compatible = "cfi-flash";
+				#address-cells = <1>;
+				#size-cells = <1>;
+				reg = <0x0 0x0 0x1000000>;
+				bank-width = <2>;
+			};
+		};
+	};
+
-- 
1.9.1




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