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[PATCHv3,2/2] dt-bindings: arm: coresight: Add support to skip trace unit power up

Message ID 7b69c9752713ce22f04688e83ec78f8aa67c63dc.1589558615.git.saiprakash.ranjan@codeaurora.org
State New
Headers show
Series coresight: etm4x: Add support to skip trace unit power up | expand

Commit Message

Sai Prakash Ranjan May 15, 2020, 4:22 p.m. UTC 
From: Tingwei Zhang <tingwei@codeaurora.org>

Add "qcom,skip-power-up" property to identify systems which can
skip powering up of trace unit since they share the same power
domain as their CPU core. This is required to identify such
systems with hardware errata which stops the CPU watchdog counter
when the power up bit is set (TRCPDCR.PU).

Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Co-developed-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
---
 Documentation/devicetree/bindings/arm/coresight.txt | 7 +++++++
 1 file changed, 7 insertions(+)
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Patch

diff --git a/Documentation/devicetree/bindings/arm/coresight.txt b/Documentation/devicetree/bindings/arm/coresight.txt
index 846f6daae71b..e4b2eda0b53b 100644
--- a/Documentation/devicetree/bindings/arm/coresight.txt
+++ b/Documentation/devicetree/bindings/arm/coresight.txt
@@ -108,6 +108,13 @@  its hardware characteristcs.
 	* arm,cp14: must be present if the system accesses ETM/PTM management
 	  registers via co-processor 14.
 
+	* qcom,skip-power-up: boolean. Indicates that an implementation can
+	  skip powering up the trace unit. TRCPDCR.PU does not have to be set
+	  on Qualcomm Technologies Inc. systems since ETMs are in the same power
+	  domain as their CPU cores. This property is required to identify such
+	  systems with hardware errata where the CPU watchdog counter is stopped
+	  when TRCPDCR.PU is set.
+
 * Optional property for TMC:
 
 	* arm,buffer-size: size of contiguous buffer space for TMC ETR