Re: [PATCH v3 01/10] Documentations: dt-bindings: Add documents of generic PECI bus, adapter and client drivers
From: Jae Hyun Yoo
Date: Mon Apr 16 2018 - 19:06:22 EST
Hi Rob,
Thanks for sharing your time. Please see my answers inline.
On 4/16/2018 10:59 AM, Rob Herring wrote:
On Tue, Apr 10, 2018 at 11:32:03AM -0700, Jae Hyun Yoo wrote:
This commit adds documents of generic PECI bus, adapter and client drivers.
"dt-bindings: ..." for the subject prefix please.
Sure, I'll change the subject.
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx>
Reviewed-by: Haiyue Wang <haiyue.wang@xxxxxxxxxxxxxxx>
Reviewed-by: James Feist <james.feist@xxxxxxxxxxxxxxx>
Reviewed-by: Vernon Mauery <vernon.mauery@xxxxxxxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxx>
Cc: Andrew Jeffery <andrew@xxxxxxxx>
Cc: Andrew Lunn <andrew@xxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Jason M Biils <jason.m.bills@xxxxxxxxxxxxxxx>
Cc: Jean Delvare <jdelvare@xxxxxxxx>
Cc: Joel Stanley <joel@xxxxxxxxx>
Cc: Julia Cartwright <juliac@xxxxxxxxxxxx>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx>
Cc: Milton Miller II <miltonm@xxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Stef van Os <stef.van.os@xxxxxxxxxxxxxxxxxxxxxxxxx>
Cc: Sumeet R Pawnikar <sumeet.r.pawnikar@xxxxxxxxx>
---
.../devicetree/bindings/peci/peci-adapter.txt | 23 ++++++++++++++++++++
.../devicetree/bindings/peci/peci-bus.txt | 15 +++++++++++++
.../devicetree/bindings/peci/peci-client.txt | 25 ++++++++++++++++++++++
This should be all one document.
Okay. I'll combine them into one document.
3 files changed, 63 insertions(+)
create mode 100644 Documentation/devicetree/bindings/peci/peci-adapter.txt
create mode 100644 Documentation/devicetree/bindings/peci/peci-bus.txt
create mode 100644 Documentation/devicetree/bindings/peci/peci-client.txt
diff --git a/Documentation/devicetree/bindings/peci/peci-adapter.txt b/Documentation/devicetree/bindings/peci/peci-adapter.txt
new file mode 100644
index 000000000000..9221374f6b11
--- /dev/null
+++ b/Documentation/devicetree/bindings/peci/peci-adapter.txt
@@ -0,0 +1,23 @@
+Generic device tree configuration for PECI adapters.
+
+Required properties:
+- compatible : Should contain hardware specific definition strings that can
+ match an adapter driver implementation.
+- reg : Should contain PECI controller registers location and length.
No need for these 2 here.
Will drop these 2.
+- #address-cells : Should be <1>.
+- #size-cells : Should be <0>.
Some details on the addressing for PECI would be good.
It is for the PECI client address. Will add details.
+
+Example:
+ peci: peci@10000000 {
+ compatible = "simple-bus";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0x0 0x10000000 0x1000>;
+
This part of the example is not relevant. Just start with the adapter
node.
Will remove that part. Thanks!
+ peci0: peci-bus@0 {
+ compatible = "soc,soc-peci";
+ reg = <0x0 0x1000>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+ };
diff --git a/Documentation/devicetree/bindings/peci/peci-bus.txt b/Documentation/devicetree/bindings/peci/peci-bus.txt
new file mode 100644
index 000000000000..90bcc791ccb0
--- /dev/null
+++ b/Documentation/devicetree/bindings/peci/peci-bus.txt
@@ -0,0 +1,15 @@
+Generic device tree configuration for PECI buses.
+
+Required properties:
+- compatible : Should be "simple-bus".
I don't understand what this has to do with PECI? "simple-bus" already
has a defined meaning.
Maybe I'm wrong but I intended to show this node is an umbrella node of
a PECI bus subsystem. What should I use then?
+- #address-cells : Should be <1>.
+- #size-cells : Should be <1>.
+- ranges : Should contain PECI controller registers ranges.
+
+Example:
+ peci: peci@10000000 {
+ compatible = "simple-bus";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0x0 0x10000000 0x1000>;
+ };
diff --git a/Documentation/devicetree/bindings/peci/peci-client.txt b/Documentation/devicetree/bindings/peci/peci-client.txt
new file mode 100644
index 000000000000..8e2bfd8532f6
--- /dev/null
+++ b/Documentation/devicetree/bindings/peci/peci-client.txt
@@ -0,0 +1,25 @@
+Generic device tree configuration for PECI clients.
+
+Required properties:
+- compatible : Should contain target device specific definition strings that can
+ match a client driver implementation.
Bindings are for h/w, not client drivers.
How are PECI devices defined?
Got it. I'll correct the description. PECI client device is Intel CPU
which is connected through a PECI bus.
+- reg : Should contain address of a client CPU. Address range of CPU
+ clients is starting from 0x30 based on PECI specification.
+ <0x30> .. <0x37> (depends on the PECI_OFFSET_MAX definition)
8 devices should be enough for anyone...
Where is PECI_OFFSET_MAX defined?
PECI_OFFSET_MAX is defined in include/linux/peci.h based on the maximum
CPU numbers of the current IA generation. I'll remove the unnecessary
details. A setting out of range would be handled accordingly in kernel.
+
+Example:
+ peci-bus@0 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ < more properties >
+
+ function@cpu0 {
Not a valid node name. "function@30" is what it probably should be. For
a new bus you can define unit-address format you like, but it must be
based on the contents of reg. However, it doesn't look like you should
create anything special here.
Got it. I'll fix these node name like function@30 and function@31.
Thanks a lot for your comments!
-Jae
+ compatible = "device,function";
+ reg = <0x30>;
+ };
+
+ function@cpu1 {
+ compatible = "device,function";
+ reg = <0x31>;
+ };
+ };
--
2.16.2
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