Add a binding for the arm architected timer hardware's memory
mapped interface. The mmio timer hardware is made up of one base
frame and a collection of up to 8 timer frames, where each of the
8 timer frames can have either one or two views. A frame
typically maps to a privilege level (user/kernel, hypervisor,
secure). The first view has full access to the registers within a
frame, while the second view can be restricted to particular
registers within a frame. Each frame must support a physical
timer. It's optional for a frame to support a virtual timer.
Cc: devicetree-discuss@xxxxxxxxxxxxxxxx
Cc: Marc Zyngier <Marc.Zyngier@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Rob Herring <robherring2@xxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
---
.../devicetree/bindings/arm/arch_timer.txt | 59 ++++++++++++++++++++--
1 file changed, 56 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/arm/arch_timer.txt b/Documentation/devicetree/bindings/arm/arch_timer.txt
index 20746e5..06fc760 100644
--- a/Documentation/devicetree/bindings/arm/arch_timer.txt
+++ b/Documentation/devicetree/bindings/arm/arch_timer.txt
@@ -1,10 +1,14 @@
* ARM architected timer
-ARM cores may have a per-core architected timer, which provides per-cpu timers.
+ARM cores may have a per-core architected timer, which provides per-cpu timers,
+or a memory mapped architected timer, which provides up to 8 frames with a
+physical and optional virtual timer per frame.
-The timer is attached to a GIC to deliver its per-processor interrupts.
+The per-core architected timer is attached to a GIC to deliver its
+per-processor interrupts via PPIs. The memory mapped timer is attached to a GIC
+to deliver its interrupts via SPIs.
-** Timer node properties:
+** CP15 Timer node properties:
- compatible : Should at least contain one of
"arm,armv7-timer"
@@ -26,3 +30,52 @@ Example:
<1 10 0xf08>;
clock-frequency = <100000000>;
};
+
+** Memory mapped timer node properties:
+
+- compatible : Should at least contain "arm,armv7-timer-mem".
+
+- clock-frequency : The frequency of the main counter, in Hz. Optional.
+
+- reg : The control frame base address.
+
+Note that #address-cells, #size-cells, and ranges shall be present to ensure
+the CPU can address a frame's registers.
+
+A timer node has up to 8 frame sub-nodes, each with the following properties:
+
+- frame-number: 0 to 7.
+
+- interrupts : Interrupt list for physical and virtual timers in that order.
+ The virtual timer interrupt is optional.
+
+- reg : The first and second view base addresses in that order. The second view
+ base address is optional.
+
+- status : "disabled" indicates the frame is not available for use. Optional.
+
+Example:
+
+ timer@f0000000 {
+ compatible = "arm,armv7-timer-mem";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges;
+ reg = <0xf0000000 0x1000>;
+ clock-frequency = <50000000>;
+
+ frame@f0001000 {
+ frame-number = <0>
+ interrupts = <0 13 0x8>,
+ <0 14 0x8>;
+ reg = <0xf0001000 0x1000>,
+ <0xf0002000 0x1000>;
+ };
+
+ frame@f0003000 {
+ frame-number = <1>
+ interrupts = <0 15 0x8>;
+ reg = <0xf0003000 0x1000>;
+ status = "disabled";
+ };
+ };
--
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