OMAP USB Glue Components

OMAP USB glue

이 문서는 OMAP MUSB 및 DWC3 glue와 OMAP 전용 component를 정의합니다.

OMAP MUSB 속성

OMAP MUSB `compatible`은 `ti,omap4-musb` 또는 `ti,omap3-musb`이고 `ti,hwmods`는 `usb_otg_hs`입니다. `multipoint`는 1, endpoint 수 `num-eps`는 16, RAM address size `ram-bits`는 12입니다.

controller와 PHY 사이 interface는 `interface-type` 0이면 ULPI, 1이면 UTMI입니다. `mode` 3은 OTG, 1은 HOST, 2는 PERIPHERAL이며 `power` 50은 host mode에서 최대 100 mA 공급을 뜻합니다.

`usb-phy`는 기존 PHY phandle, `phys`와 `phy-names`는 generic PHY framework 연결입니다. 선택 `ctrl-module`은 glue가 mailbox에 쓰는 control module phandle입니다.

OMAP MUSB GLUE
 - compatible : Should be "ti,omap4-musb" or "ti,omap3-musb"
 - ti,hwmods : must be "usb_otg_hs"
 - multipoint : Should be "1" indicating the musb controller supports
   multipoint. This is a MUSB configuration-specific setting.
 - num-eps : Specifies the number of endpoints. This is also a
   MUSB configuration-specific setting. Should be set to "16"
 - ram-bits : Specifies the ram address size. Should be set to "12"
 - interface-type : This is a board specific setting to describe the type of
   interface between the controller and the phy. It should be "0" or "1"
   specifying ULPI and UTMI respectively.
 - mode : Should be "3" to represent OTG. "1" signifies HOST and "2"
   represents PERIPHERAL.
 - power : Should be "50". This signifies the controller can supply up to
   100mA when operating in host mode.
 - usb-phy : the phandle for the PHY device
 - phys : the phandle for the PHY device (used by generic PHY framework)
 - phy-names : the names of the PHY corresponding to the PHYs present in the
   *phy* phandle.

Optional properties:
 - ctrl-module : phandle of the control module this glue uses to write to
   mailbox

OMAP4 MUSB SoC·board 예제

SoC node `usb_otg_hs@4a0ab000`은 multipoint 1, endpoint 16개, RAM 12 bit, OMAP USB control module과 USB2 PHY를 지정합니다. board node는 UTMI interface 1, OTG mode 3, power 50을 설정합니다.

SOC specific device node entry
usb_otg_hs: usb_otg_hs@4a0ab000 {
        compatible = "ti,omap4-musb";
        ti,hwmods = "usb_otg_hs";
        multipoint = <1>;
        num-eps = <16>;
        ram-bits = <12>;
        ctrl-module = <&omap_control_usb>;
        phys = <&usb2_phy>;
        phy-names = "usb2-phy";
};

Board specific device node entry
&usb_otg_hs {
        interface-type = <1>;
        mode = <3>;
        power = <50>;
};

OMAP DWC3 속성과 subnode

OMAP5와 DRA7의 DWC3 glue는 `ti,dwc3`, AM437x는 `ti,am437x-dwc3`를 사용하며 `ti,hwmods`는 `usb_otg_ss`입니다. `reg`는 register set, `interrupts`는 MPU를 깨우는 IRQ입니다.

subnode가 있으면 address·size cell을 정의해야 합니다. `utmi-mode` 1은 VBUS·OTG ID status의 hardware source, 2는 software source이며 `ranges`는 child address를 parent에 1:1 mapping합니다.

선택 `extcon`은 connect/disconnect 감지 장치이고 `vbus-supply`는 필요한 regulator입니다. DWC3 core는 `snps,dwc3.yaml` binding을 따르는 child `dwc3`로 추가합니다.

OMAP DWC3 GLUE
 - compatible : Should be
        * "ti,dwc3" for OMAP5 and DRA7
        * "ti,am437x-dwc3" for AM437x
 - ti,hwmods : Should be "usb_otg_ss"
 - reg : Address and length of the register set for the device.
 - interrupts : The irq number of this device that is used to interrupt the
   MPU
 - #address-cells, #size-cells : Must be present if the device has sub-nodes
 - utmi-mode : controls the source of UTMI/PIPE status for VBUS and OTG ID.
   It should be set to "1" for HW mode and "2" for SW mode.
 - ranges: the child address space are mapped 1:1 onto the parent address space

Optional Properties:
 - extcon : phandle for the extcon device omap dwc3 uses to detect
   connect/disconnect events.
 - vbus-supply : phandle to the regulator device tree node if needed.

Sub-nodes:
The dwc3 core should be added as subnode to omap dwc3 glue.
- dwc3 :
   The binding details of dwc3 can be found in:
   Documentation/devicetree/bindings/usb/snps,dwc3.yaml

OMAP DWC3 glue 예제

예제 `omap_dwc3`은 `ti,dwc3`, `usb_otg_ss`, register 0x4a020000/0x1ff, interrupt 93, 1-cell child 주소·크기, software UTMI mode 2와 direct `ranges`를 사용합니다.

omap_dwc3 {
        compatible = "ti,dwc3";
        ti,hwmods = "usb_otg_ss";
        reg = <0x4a020000 0x1ff>;
        interrupts = <0 93 4>;
        #address-cells = <1>;
        #size-cells = <1>;
        utmi-mode = <2>;
        ranges;
};