summaryrefslogtreecommitdiff
path: root/Documentation/devicetree/bindings/clock/qoriq-clock.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/devicetree/bindings/clock/qoriq-clock.txt')
-rw-r--r--Documentation/devicetree/bindings/clock/qoriq-clock.txt61
1 files changed, 50 insertions, 11 deletions
diff --git a/Documentation/devicetree/bindings/clock/qoriq-clock.txt b/Documentation/devicetree/bindings/clock/qoriq-clock.txt
index df4a259a6898..16a3ec433119 100644
--- a/Documentation/devicetree/bindings/clock/qoriq-clock.txt
+++ b/Documentation/devicetree/bindings/clock/qoriq-clock.txt
@@ -1,6 +1,6 @@
* Clock Block on Freescale QorIQ Platforms
-Freescale qoriq chips take primary clocking input from the external
+Freescale QorIQ chips take primary clocking input from the external
SYSCLK signal. The SYSCLK input (frequency) is multiplied using
multiple phase locked loops (PLL) to create a variety of frequencies
which can then be passed to a variety of internal logic, including
@@ -13,14 +13,16 @@ which the chip complies.
Chassis Version Example Chips
--------------- -------------
1.0 p4080, p5020, p5040
-2.0 t4240, b4860, t1040
+2.0 t4240, b4860
1. Clock Block Binding
Required properties:
-- compatible: Should contain a specific clock block compatible string
- and a single chassis clock compatible string.
- Clock block strings include, but not limited to, one of the:
+- compatible: Should contain a chip-specific clock block compatible
+ string and (if applicable) may contain a chassis-version clock
+ compatible string.
+
+ Chip-specific strings are of the form "fsl,<chip>-clockgen", such as:
* "fsl,p2041-clockgen"
* "fsl,p3041-clockgen"
* "fsl,p4080-clockgen"
@@ -30,15 +32,14 @@ Required properties:
* "fsl,b4420-clockgen"
* "fsl,b4860-clockgen"
* "fsl,ls1021a-clockgen"
- Chassis clock strings include:
+ Chassis-version clock strings include:
* "fsl,qoriq-clockgen-1.0": for chassis 1.0 clocks
* "fsl,qoriq-clockgen-2.0": for chassis 2.0 clocks
- reg: Describes the address of the device's resources within the
address space defined by its parent bus, and resource zero
represents the clock register set
-- clock-frequency: Input system clock frequency
-Recommended properties:
+Optional properties:
- ranges: Allows valid translation between child's address space and
parent's. Must be present if the device has sub-nodes.
- #address-cells: Specifies the number of cells used to represent
@@ -47,8 +48,46 @@ Recommended properties:
- #size-cells: Specifies the number of cells used to represent
the size of an address. Must be present if the device has
sub-nodes and set to 1 if present
+- clock-frequency: Input system clock frequency (SYSCLK)
+- clocks: If clock-frequency is not specified, sysclk may be provided
+ as an input clock. Either clock-frequency or clocks must be
+ provided.
+
+2. Clock Provider
+
+The clockgen node should act as a clock provider, though in older device
+trees the children of the clockgen node are the clock providers.
+
+When the clockgen node is a clock provider, #clock-cells = <2>.
+The first cell of the clock specifier is the clock type, and the
+second cell is the clock index for the specified type.
+
+ Type# Name Index Cell
+ 0 sysclk must be 0
+ 1 cmux index (n in CLKCnCSR)
+ 2 hwaccel index (n in CLKCGnHWACSR)
+ 3 fman 0 for fm1, 1 for fm2
+ 4 platform pll 0=pll, 1=pll/2, 2=pll/3, 3=pll/4
+
+3. Example
+
+ clockgen: global-utilities@e1000 {
+ compatible = "fsl,p5020-clockgen", "fsl,qoriq-clockgen-1.0";
+ clock-frequency = <133333333>;
+ reg = <0xe1000 0x1000>;
+ #clock-cells = <2>;
+ };
+
+ fman@400000 {
+ ...
+ clocks = <&clockgen 3 0>;
+ ...
+ };
+}
+4. Legacy Child Nodes
-2. Clock Provider/Consumer Binding
+NOTE: These nodes are deprecated. Kernels should continue to support
+device trees with these nodes, but new device trees should not use them.
Most of the bindings are from the common clock binding[1].
[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
@@ -82,7 +121,7 @@ Recommended properties:
- reg: Should be the offset and length of clock block base address.
The length should be 4.
-Example for clock block and clock provider:
+Legacy Example:
/ {
clockgen: global-utilities@e1000 {
compatible = "fsl,p5020-clockgen", "fsl,qoriq-clockgen-1.0";
@@ -142,7 +181,7 @@ Example for clock block and clock provider:
};
};
-Example for clock consumer:
+Example for legacy clock consumer:
/ {
cpu0: PowerPC,e5500@0 {