[PATCH v4 2/2] dt-bindings/interrupt-controller: pdc: descibe PDC device binding

From: Lina Iyer
Date: Wed Feb 07 2018 - 10:50:15 EST


From: Archana Sathyakumar <asathyak@xxxxxxxxxxxxxx>

Add device binding documentation for the PDC Interrupt controller on
QCOM SoC's like the SDM845. The interrupt-controller can be used to
sense edge low interrupts and wakeup interrupts when the GIC is
non-operational.

Cc: devicetree@xxxxxxxxxxxxxxx
Signed-off-by: Archana Sathyakumar <asathyak@xxxxxxxxxxxxxx>
Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
---
.../bindings/interrupt-controller/qcom,pdc.txt | 80 ++++++++++++++++++++++
1 file changed, 80 insertions(+)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt

diff --git a/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt b/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt
new file mode 100644
index 000000000000..21c4f2fbcd0b
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt
@@ -0,0 +1,80 @@
+PDC interrupt controller
+
+Qualcomm Technologies Inc. SoCs based on the RPM Hardened architecture have a
+Power Domain Controller (PDC) that is on always-on domain. In addition to
+providing power control for the power domains, the hardware also has an
+interrupt controller that can be used to help detect edge low interrupts as
+well detect interrupts when the GIC is non-operational.
+
+GIC is parent interrupt controller at the highest level. Platform interrupt
+controller PDC is next in hierarchy, followed by others. Drivers requiring
+wakeup capabilities of their device interrupts routed through the PDC, must
+specify PDC as their interrupt controller and request the PDC port associated
+with the GIC interrupt. See example below.
+
+Properties:
+
+- compatible:
+ Usage: required
+ Value type: <string>
+ Definition: Should contain "qcom,<soc>-pdc"
+ - "qcom,sdm845-pdc": For SDM845
+
+- reg:
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: Specifies the base physical address for PDC hardware.
+
+- interrupt-cells:
+ Usage: required
+ Value type: <u32>
+ Definition: Specifies the number of cells needed to encode an interrupt
+ source.
+ Must be 2.
+ The first element of the tuple is the PDC pin for the
+ interrupt.
+ The second element is the trigger type.
+
+- interrupt-parent:
+ Usage: required
+ Value type: <phandle>
+ Definition: Specifies the interrupt parent necessary for hierarchical
+ domain to operate.
+
+- interrupt-controller:
+ Usage: required
+ Value type: <bool>
+ Definition: Identifies the node as an interrupt controller.
+
+- qcom,pdc-ranges:
+ Usage: required
+ Value type: <u32 array>
+ Definition: Specifies the PDC pin offset and the number of PDC ports.
+ The tuples indicates the valid mapping of valid PDC ports
+ and their hwirq mapping.
+ The first element of the tuple is the starting PDC port.
+ The second element is the GIC hwirq number for the PDC port.
+ The third element is the number of interrupts in sequence.
+
+Example:
+
+ pdc: interrupt-controller@b220000 {
+ compatible = "qcom,sdm845-pdc";
+ reg = <0xb220000 0x30000>;
+ qcom,pdc-ranges = <0 512 94>, <94 641 15>, <115 662 7>;
+ #interrupt-cells = <2>;
+ interrupt-parent = <&intc>;
+ interrupt-controller;
+ };
+
+DT binding of a device that wants to use the GIC SPI 514 as a wakeup
+interrupt, must do -
+
+ wake-device {
+ [...]
+ interrupt-controller = <&pdc>;
+ interrupt = <2 IRQ_TYPE_LEVEL_HIGH>;
+ };
+
+In this case interrupt 514 would be mapped to port 2 on the PDC as defined by
+the qcom,pdc-ranges property.
--
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