clocksource/drivers/sysctr: Add nxp system counter timer driver support

The system counter (sys_ctr) is a programmable system counter
which provides a shared time base to the Cortex A15, A7, A53 etc cores.
It is intended for use in applications where the counter is always
powered on and supports multiple, unrelated clocks. The sys_ctr hardware
supports:
 - 56-bit counter width (roll-over time greater than 40 years)
 - compare frame(64-bit compare value) contains programmable interrupt
   generation when compare value <= counter value.

[dlezcano] Fixed over 80 chars length warning

Signed-off-by: Bai Ping <ping.bai@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

1 files changed, 25 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt b/Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt
new file mode 100644
index 000000000000..d57659996d62
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt
@@ -0,0 +1,25 @@
+NXP System Counter Module(sys_ctr)
+
+The system counter(sys_ctr) is a programmable system counter which provides
+a shared time base to Cortex A15, A7, A53, A73, etc. it is intended for use in
+applications where the counter is always powered and support multiple,
+unrelated clocks. The compare frame inside can be used for timer purpose.
+
+Required properties:
+
+- compatible :      should be "nxp,sysctr-timer"
+- reg :             Specifies the base physical address and size of the comapre
+                    frame and the counter control, read & compare.
+- interrupts :      should be the first compare frames' interrupt
+- clocks : 	    Specifies the counter clock.
+- clock-names: 	    Specifies the clock's name of this module
+
+Example:
+
+	system_counter: timer@306a0000 {
+		compatible = "nxp,sysctr-timer";
+		reg = <0x306a0000 0x20000>;/* system-counter-rd & compare */
+		clocks = <&clk_8m>;
+		clock-names = "per";
+		interrupts = <GIC_SPI 47 IRQ_TYPE_LEVEL_HIGH>;
+	};