Documentation: dt: emif: device tree bindings for TI's EMIF sdram controller

EMIF - External Memory Interface - is an SDRAM controller used in
TI SoCs. EMIF supports, based on the IP revision, one or more of
DDR2/DDR3/LPDDR2 protocols. This binding describes a given instance
of the EMIF IP and memory parts attached to it.

Reviewed-by: Grant Likely <[e-mail]>
Tested-by: Lokesh Vutla <[e-mail]>
Signed-off-by: Aneesh V <[e-mail]>
[[e-mail]: Rebased against 3.6-rc]
Signed-off-by: Santosh Shilimkar <[e-mail]>
Signed-off-by: Benoit Cousson <[e-mail]>

Documentation/devicetree/bindings/memory-controllers/ti/emif.txt

···
+* EMIF family of TI SDRAM controllers
+
+EMIF - External Memory Interface - is an SDRAM controller used in
+TI SoCs. EMIF supports, based on the IP revision, one or more of
+DDR2/DDR3/LPDDR2 protocols. This binding describes a given instance
+of the EMIF IP and memory parts attached to it.
+
+Required properties:
+- compatible	: Should be of the form "ti,emif-<ip-rev>" where <ip-rev>
+  is the IP revision of the specific EMIF instance.
+
+- phy-type	: <u32> indicating the DDR phy type. Following are the
+  allowed values
+  <1>	: Attila PHY
+  <2>	: Intelli PHY
+
+- device-handle	: phandle to a "lpddr2" node representing the memory part
+
+- ti,hwmods	: For TI hwmods processing and omap device creation
+  the value shall be "emif<n>" where <n> is the number of the EMIF
+  instance with base 1.
+
+Optional properties:
+- cs1-used		: Have this property if CS1 of this EMIF
+  instance has a memory part attached to it. If there is a memory
+  part attached to CS1, it should be the same type as the one on CS0,
+  so there is no need to give the details of this memory part.
+
+- cal-resistor-per-cs	: Have this property if the board has one
+  calibration resistor per chip-select.
+
+- hw-caps-read-idle-ctrl: Have this property if the controller
+  supports read idle window programming
+
+- hw-caps-dll-calib-ctrl: Have this property if the controller
+  supports dll calibration control
+
+- hw-caps-ll-interface	: Have this property if the controller
+  has a low latency interface and corresponding interrupt events
+
+- hw-caps-temp-alert	: Have this property if the controller
+  has capability for generating SDRAM temperature alerts
+
+Example:
+
+emif1: emif@0x4c000000 {
+	compatible	= "ti,emif-4d";
+	ti,hwmods	= "emif2";
+	phy-type	= <1>;
+	device-handle	= <&elpida_ECB240ABACN>;
+	cs1-used;
+	hw-caps-read-idle-ctrl;
+	hw-caps-ll-interface;
+	hw-caps-temp-alert;
+};