On 01/04/2022 07:04, Aswath Govindraju wrote: > Hi Rob, > > On 01/04/22 05:50, Rob Herring wrote: >> On Thu, Mar 24, 2022 at 12:53:08PM +0100, Krzysztof Kozlowski wrote: >>> On 24/03/2022 12:40, Aswath Govindraju wrote: >>>> Hi Krzysztof, >>>> >>>> On 24/03/22 16:37, Krzysztof Kozlowski wrote: >>>>> On 24/03/2022 08:34, Aswath Govindraju wrote: >>>>>> Add bindings for the TI's AM62 wrapper module for the Synopsys USBSS-DRD >>>>>> controller. >>>>>> >>>>>> Signed-off-by: Aswath Govindraju <a-govindraju@xxxxxx> >>>>>> --- >>>>>> >>>>>> Changes since v1: >>>>>> - made correction in grammer of clocks property description >>>>>> and added maxItems in the interrupts property based on comments >>>>>> received from Roger >>>>>> - corrected the title, fixed the description of >>>>>> ti,syscon-phy-pll-refclk, added pattern properties and child node >>>>>> in the example based on the comments from Krzysztof. >>>>>> >>>>>> .../devicetree/bindings/usb/ti,am62-usb.yaml | 117 ++++++++++++++++++ >>>>>> 1 file changed, 117 insertions(+) >>>>>> create mode 100644 Documentation/devicetree/bindings/usb/ti,am62-usb.yaml >>>>>> >>>>>> diff --git a/Documentation/devicetree/bindings/usb/ti,am62-usb.yaml b/Documentation/devicetree/bindings/usb/ti,am62-usb.yaml >>>>>> new file mode 100644 >>>>>> index 000000000000..452bfdc6fb09 >>>>>> --- /dev/null >>>>>> +++ b/Documentation/devicetree/bindings/usb/ti,am62-usb.yaml >>>>>> @@ -0,0 +1,117 @@ >>>>>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause >>>>>> +%YAML 1.2 >>>>>> +--- >>>>>> +$id: http://devicetree.org/schemas/usb/ti,am62-usb.yaml# >>>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>>>>> + >>>>>> +title: TI's AM62 wrapper module for the Synopsys USBSS-DRD controller >>>>>> + >>>>>> +maintainers: >>>>>> + - Aswath Govindraju <a-govindraju@xxxxxx> >>>>>> + >>>>>> +properties: >>>>>> + compatible: >>>>>> + const: ti,am62-usb >>>>>> + >>>>>> + reg: >>>>>> + maxItems: 1 >>>>>> + >>>>>> + ranges: true >>>>>> + >>>>>> + power-domains: >>>>>> + description: >>>>>> + PM domain provider node and an args specifier containing >>>>>> + the USB ISO device id value. See, >>>>>> + Documentation/devicetree/bindings/soc/ti/sci-pm-domain.yaml >>>>>> + maxItems: 1 >>>>>> + >>>>>> + clocks: >>>>>> + description: Clock phandle to usb2_refclk >>>>>> + maxItems: 1 >>>>>> + >>>>>> + clock-names: >>>>>> + items: >>>>>> + - const: ref >>>>>> + >>>>>> + id-gpio: >>>>>> + description: >>>>>> + GPIO to be used as ID pin >>>>>> + maxItems: 1 >>>>> >>>>> I have doubts about this. If you USB controller handles the ID pin, then >>>>> probably this should be moved to usb-connector.yaml. I did not see >>>>> id-gpio in any other USB controller blocks. >>>>> >>>> >>>> Yes, the USB wrapper handles the ID pin operation only. It also reads >>>> the status of VBUS by reading a register from its MMR and not using a >>>> gpio. After evaluating the role the based on the states if id pin and >>>> VBUS, this role is communicated to the dwc3 core driver using extcon. >>>> There is no way for the dwc3 driver to detect the role on its own. >>>> >>>> >>>> The usb-connector(drivers/usb/common/usb-conn-gpio.c) driver, seems to >>>> be implemented for driving the VBUS, based on ID and VBUS pin status. >>>> However, in case of the above implementation we need to communicate the >>>> detected role to the dwc3 core driver. Also, the wrapper does not >>>> control VBUS but it is the dwc3 core driver that drives the VBUS. >>>> Therefore, I think the usb-connector implementation cannot be used here. >>> >>> I don't think about usb-conn-gpio.c but using the binding generic >>> binding for usb-X-connector and define a connector with ID. >>> >>> Actually Rob could help here. >>> >>> Rob, >>> Should the id-gpio be modeled as a property in this glue/wrapper driver >>> or rather as part of usb-connector child node? >> >> That's a simple question. Where does the ID GPIO signal go to? The >> connector, so it goes in the connector node. >> > > Thank you for the clarification. Here ID-gpio is directly read by the > wrapper and hence, I have modeled it as a property in the wrapper dt > node. May I know if this wrong and should the modelling be looked at > differently? What do you mean here by "read"? If you refer to the driver reading the pin value, it is less related to the hardware, right? Best regards, Krzysztof
