On Fri, Mar 17, 2017 at 10:13:35AM -0600, Mathieu Poirier wrote:

On Fri, Mar 17, 2017 at 11:02:17PM +0800, Leo Yan wrote:

quoted

According to ARMv8 architecture reference manual (ARM DDI 0487A.k)
Chapter 'Part H: External debug', the CPU can integrate debug module
and it can support self-hosted debug and external debug. Especially
for supporting self-hosted debug, this means the program can access
the debug module from mmio region; and usually the mmio region is
integrated with coresight.

So add document for binding debug component, includes binding to APB
clock; and also need specify the CPU node which the debug module is
dedicated to specific CPU.

Suggested-by: Mike Leach <redacted>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Leo Yan <redacted>
---
 .../bindings/arm/coresight-cpu-debug.txt           | 46 ++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt

diff --git a/Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt b/Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt
new file mode 100644
index 0000000..f6855c3
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt

@@ -0,0 +1,46 @@
+* CoreSight CPU Debug Component:
+
+CoreSight cpu debug component are compliant with the ARMv8 architecture
+reference manual (ARM DDI 0487A.k) Chapter 'Part H: External debug'. The
+external debug module is mainly used for two modes: self-hosted debug and
+external debug, and it can be accessed from mmio region from Coresight
+and eventually the debug module connects with CPU for debugging. And the
+debug module provides sample-based profiling extension, which can be used
+to sample CPU program counter, secure state and exception level, etc;
+usually every CPU has one dedicated debug module to be connected.
+
+Required properties:
+
+- compatible : should be
+	     * "arm,coresight-cpu-debug"; supplemented with "arm,primecell"
+	       since this driver is using the AMBA bus interface.

This description needs to be refactored - see my comment from an earlier post
for more details.

quoted

+
+- reg : physical base address and length of the register set.
+
+- clocks : the clock associated to this component.
+
+- clock-names : the name of the clock referenced by the code. Since we are
+                using the AMBA framework, the name of the clock providing
+		the interconnect should be "apb_pclk" and the clock is
+		mandatory. The interface between the debug logic and the
+		processor core is clocked by the internal CPU clock, so it
+		is enabled with CPU clock by default.
+
+- cpu : the cpu phandle the debug module is affined to. When omitted
+	the module is considered to belong to CPU0.
+
+Optional properties:

s/properties/property

I prefer it as-is. Then it doesn't need to be changed if we add 
properties.

Rob