On Fri, Nov 16, 2018 at 8:29 PM Chen Yu [off-list ref] wrote:

Hi,

On 2018/11/13 0:02, Rob Herring wrote:

quoted

On Sat, Oct 27, 2018 at 05:58:11PM +0800, Yu Chen wrote:

quoted

This patch adds binding descriptions to support the dwc3 controller
on HiSilicon SoCs and boards like the HiKey960.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: John Stultz <redacted>
Signed-off-by: Yu Chen <chenyu56@huawei.com>
---
 .../devicetree/bindings/usb/dwc3-hisi.txt          | 53 ++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/usb/dwc3-hisi.txt

diff --git a/Documentation/devicetree/bindings/usb/dwc3-hisi.txt b/Documentation/devicetree/bindings/usb/dwc3-hisi.txt
new file mode 100644
index 000000000000..e715e7b1c324
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/dwc3-hisi.txt

@@ -0,0 +1,53 @@
+HiSilicon DWC3 USB SoC controller
+
+This file documents the parameters for the dwc3-hisi driver.
+
+Required properties:
+- compatible:       should be "hisilicon,hi3660-dwc3"
+- clocks:   A list of phandle + clock-specifier pairs for the
+            clocks listed in clock-names
+- clock-names:      Specify clock names
+- resets:   list of phandle and reset specifier pairs.
+
+Sub-nodes:
+The dwc3 core should be added as subnode to HiSilicon DWC3 as shown in the
+example below. The DT binding details of dwc3 can be found in:
+Documentation/devicetree/bindings/usb/dwc3.txt

If you only have clocks and resets and no glue registers, then you
don't need a sub-node. Just make the controller one node.

In dwc3 glue driver，the controller driver usually probed by call of_platform_populate
which will search the child node of glue driver.
The code of function of_platform_populate is as below:

        for_each_child_of_node(root, child) {
                 rc = of_platform_bus_create(child, matches, lookup, parent, true);
                 if (rc) {
                         of_node_put(child);
                         break;
                 }
         }

So I think the controller node should be a sub-node.

It was done that way, but has changed. See commit fe8abf332b8f ("usb:
dwc3: support clocks and resets for DWC3 core").

Rob