On Wed, Jun 17, 2020 at 8:38 AM Mike Looijmans <mike.looijmans@xxxxxxxx> wrote: > > > Met vriendelijke groet / kind regards, > > Mike Looijmans > System Expert > > > TOPIC Embedded Products B.V. > Materiaalweg 4, 5681 RJ Best > The Netherlands > > T: +31 (0) 499 33 69 69 > E: mike.looijmans@xxxxxxxxxxxxxxxxx > W: www.topicproducts.com > > Please consider the environment before printing this e-mail > On 10-06-2020 22:22, Rob Herring wrote: > > On Wed, Jun 03, 2020 at 02:09:15PM +0200, Mike Looijmans wrote: > >> Support VBUS power control using regulator framework. Enables the regulator > >> while the port is in host mode. > >> > >> Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx> > >> --- > >> v2: Add missing devm_regulator_get call which got lost during rebase > >> > >> .../devicetree/bindings/usb/dwc3.txt | 1 + > >> drivers/usb/dwc3/core.c | 34 ++++++++++++++----- > >> drivers/usb/dwc3/core.h | 4 +++ > >> drivers/usb/dwc3/drd.c | 6 ++-- > >> 4 files changed, 33 insertions(+), 12 deletions(-) > >> > >> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt > >> index 9946ff9ba735..56bc3f238e2d 100644 > >> --- a/Documentation/devicetree/bindings/usb/dwc3.txt > >> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt > >> @@ -37,6 +37,7 @@ Optional properties: > >> - phys: from the *Generic PHY* bindings > >> - phy-names: from the *Generic PHY* bindings; supported names are "usb2-phy" > >> or "usb3-phy". > >> + - vbus-supply: Regulator handle that provides the VBUS power. > > Does the DWC3 block require Vbus to power itself? Doubtful. This > > belongs in a usb-connector node. If the DWC3 driver wants to get the > > Vbus supply, it can fetch it from that node. > > > > Rob > > Okay, I've been digging into that. But there's no actual driver that > binds to a "usb-b-connector" compatible, so how do we get to the > vbus-supply from there? > > [devm_]regulator_get only accepts a device as argument, and will not > look into child nodes. The only way to get at the vbus of a child node > (or a node linked through a port) would be to hand-code the equivalent > of of_regulator_get(), which will not be acceptable. Doesn't it look into child nodes calling of_get_child_regulator()? You're right that it wouldn't work if graph is used. The connector has to be either a child of a controller for the connector or the USB controller. I'd expect you'd have the former for Type-C, but for "usb-b-connector" the parent is more likely just the USB controller. In any case, having a struct device shouldn't be a requirement and most subsystems expose a get function only needing the DT node. > Or is it the intention that I write a usb-X-connector device driver > first that handles the vbus? That's a kernel implementation detail that is independent of the binding, but yes we'll probably need a driver or library helper functions eventually. Note that it is possible to have a struct device without a driver. Rob
