On 06/18/14 01:34, Srinivas Kandagatla wrote:

On 18/06/14 00:59, Stephen Boyd wrote:

quoted

On 06/16/14 11:46, Bjorn Andersson wrote:

quoted

diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,rpm.txt

b/Documentation/devicetree/bindings/soc/qcom/qcom,rpm.txt
new file mode 100644
index 0000000..0366533

--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/qcom/qcom,rpm.txt

@@ -0,0 +1,260 @@
+Qualcomm Resource Power Manager (RPM)
+

[...]

quoted

+
+- reg:
+    Usage: required
+    Value type: <prop-encoded-array>
+    Definition: two entries specifying the RPM's message ram and
ipc register
+
+- reg-names:
+    Usage: required
+    Value type: <string-array>
+    Definition: must contain the following, in order:
+            "msg_ram"
+            "ipc"

ipc is concerning....

quoted

+    rpm@108000 {
+        compatible = "qcom,rpm-msm8960";
+        reg = <0x108000 0x1000 0x2011008 0x4>;
+

(reg-names is missing from the example)

because ipc is actually a register inside the Krait complex's global
clock control/distribution hardware block (it's located at 0x2011000).
 From what I can tell, this is the only non-clock/power register inside
there. I plan to send out a driver for this hardware block so that I can
switch the L2 aux source mux over to PLL8 instead of PXO (done with a
single register write to 0x2011028) and this mapping/use here is going
to conflict with that unless I only map the single register like is done
here.

I wonder if we'd be better off making this region a separate node and
having some phandle to it here in the RPM node? That way we have a

Can't we use syscon based on regmap here?  syscon is a better way to
share a common register space across multiple drivers.

How would the mux clock be registered? I'd like it to be registered by
the driver associated with this device with something like
devm_clk_register(). From what I can tell syscon wouldn't allow that
unless we extend the syscon driver to handle more specific compatible
strings.

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