lkml.org 
[lkml]   [2014]   [Nov]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 06/11] memory: atmel-ebi: add DT bindings documentation
Date
Signed-off-by: Boris Brezillon <boris.brezillon@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@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@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@0,0 {
+ compatible = "cfi-flash";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ reg = <0x0 0x0 0x1000000>;
+ bank-width = <2>;
+ };
+ };
+ };
+
--
1.9.1


\
 
 \ /
  Last update: 2014-11-05 17:41    [W:0.166 / U:0.216 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site