On Wed, Sep 14, 2016 at 01:55:02AM -0700, Stephen Boyd wrote: > Quoting Stephen Boyd (2016-09-13 18:42:46) > > On the db410c 96boards platform we have a TC7USB40MU[1] on the > > board to mux the D+/D- lines from the SoC between a micro usb > > "device" port and a USB hub for "host" roles. Upon a role switch, > > we need to change this mux to forward the D+/D- lines to either > > the port or the hub. Therefore, introduce a driver for this > > device that intercepts extcon USB_HOST events and logically > > asserts a gpio to mux the "host" D+/D- lines when a host cable is > > attached. When the cable goes away, it will logically deassert > > the gpio and mux the "device" lines. > > > > [1] https://toshiba.semicon-storage.com/ap-en/product/logic/bus-switch/detail.TC7USB40MU.html > > > > Cc: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx> > > Cc: Chanwoo Choi <cw00.choi@xxxxxxxxxxx> > > Cc: <devicetree@xxxxxxxxxxxxxxx> > > Signed-off-by: Stephen Boyd <stephen.boyd@xxxxxxxxxx> > > --- > > > > Should I make the extcon part optional? I could see a case where there are two > > "OTG" ports connected to the mux (or two hubs), and for some reason the > > software may want to mux between them at runtime. If we mandate an extcon, > > that won't be possible to support. Perhaps it would be better to have > > the node, but connect it to the usb controller with a phandle (maybe of_graph > > endpoints would be useful too) so that when the controller wants to mux over > > a port it can do so. > > Here's some dts mock-up on top of the db410c for the of_graph stuff. I > haven't written any code around it, but the idea is to allow the binding > to specify how the mux is connected to upstream and downstream D+/D- > lines. This way, we can do some dt parsing of the endpoints and their > parent nodes to figure out if the mux needs to be set high or low to use > a device connector or a usb hub based on if the id cable is present. > Maybe I'm over thinking things though and we could just have a DT > property for that. > > soc { > usb@78d9000 { > extcon = <&usb_id>, <&usb_id>; Why you have two same extcon phandler? From my mind, one should id, another should is vbus. Besides, I find extcon-usb-gpio.c is lack of vbus support, how you support vbus detection for connection/disconnection with PC for your chipidea msm patch set? > usb-controller; // needed? Not needed. You only need to describe controller, mux ic, and hub (if you need platform stuffs the driver needs to know). Peter > > ports { > #address-cells = <1>; > #size-cells = <0>; > > port@0 { > #address-cells = <1>; > #size-cells = <0>; > reg = <0>; > > usb_output: endpoint@0 { // USB D+/D- > reg = <0>; > remote-endpoint = <&usb_switch_input>; > }; > }; > }; > }; > }; > > usb2513 { > compatible = "smsc,usb3503"; > reset-gpios = <&pm8916_gpios 3 GPIO_ACTIVE_LOW>; > initial-mode = <1>; > usb-hub; // indicate this is a hub > > ports { > #address-cells = <1>; > #size-cells = <0>; > > port@0 { > #address-cells = <1>; > #size-cells = <0>; > reg = <0>; > > usb_hub_input: endpoint@0 { // USB{DP,DM}_UP > reg = <0>; > remote-endpoint = <&usb_switch_hub_ep>; > }; > > usb_hub_output1: endpoint@1 { // USB{DP,DM}_DN1 > reg = <1>; > remote-endpoint = <&usb_a2_connector>; > }; > > usb_hub_output2: endpoint@2 { // USB{DP,DM}_DN2 > reg = <2>; > remote-endpoint = <&usb_a1_connector>; > }; > > usb_hub_output3: endpoint@3 { // USB{DP,DM}_DN3 > reg = <3>; > // goes to expansion connector > }; > }; > }; > }; > > usb_id: usb-id { > compatible = "linux,extcon-usb-gpio"; > id-gpio = <&msmgpio 121 GPIO_ACTIVE_HIGH>; > pinctrl-names = "default"; > pinctrl-0 = <&usb_id_default>; > }; > > usb-switch { > compatible = "toshiba,tc7usb40mu"; > switch-gpios = <&pm8916_gpios 4 GPIO_ACTIVE_HIGH>; > extcon = <&usb_id>; > pinctrl-names = "default"; > pinctrl-0 = <&usb_sw_sel_pm>; > > ports { > #address-cells = <1>; > #size-cells = <0>; > > port@0 { > #address-cells = <1>; > #size-cells = <0>; > reg = <0>; > > usb_switch_input: endpoint@0 { // D+/D- > reg = <0>; > remote-endpoint = <&usb_output>; > }; > > usb_switch_device_ep: endpoint@1 { // D1+/D1- > reg = <1>; > remote-endpoint = <&usb_ub_connector>; > }; > > usb_switch_hub_ep: endpoint@2 { // D2+/D2- > reg = <2>; > remote-endpoint = <&usb_hub_input>; > }; > }; > }; > }; > > uB-connector { > compatible = "usb-ub-connector"; > #address-cells = <1>; > #size-cells = <0>; > usb-connector; > port@0 { > #address-cells = <1>; > #size-cells = <0>; > reg = <0>; > usb_ub_connector: endpoint@0 { > reg = <0>; > remote-endpoint = <&usb_switch_device_ep>; > }; > }; > }; > > usb-A-connector1 { > compatible = "usb-A-connector"; > #address-cells = <1>; > #size-cells = <0>; > usb-connector; > port@0 { > #address-cells = <1>; > #size-cells = <0>; > reg = <0>; > usb_a1_connector: endpoint@0 { > reg = <0>; > remote-endpoint = <&usb_hub_output2>; > }; > }; > }; > > usb-A-connector2 { > compatible = "usb-A-connector"; > #address-cells = <1>; > #size-cells = <0>; > usb-connector; > port@0 { > #address-cells = <1>; > #size-cells = <0>; > reg = <0>; > usb_a2_connector: endpoint@0 { > reg = <0>; > remote-endpoint = <&usb_hub_output1>; > }; > }; > }; > }; > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
