Hi, On Mon, 2019-05-20 at 09:45 +0000, Biju Das wrote: > > Hi Heikki, > > Thanks for the feedback. > > > Subject: Re: [PATCH v5 4/6] usb: roles: add API to get usb_role_switch by > > node > > > > On Mon, May 20, 2019 at 08:06:41AM +0000, Biju Das wrote: > > > Hi Heikki, > > > > > > > Subject: Re: [PATCH v5 4/6] usb: roles: add API to get > > > > usb_role_switch by node > > > > > > > > On Mon, May 20, 2019 at 10:39:11AM +0800, Chunfeng Yun wrote: > > > > > Hi, > > > > > On Fri, 2019-05-17 at 16:05 +0300, Heikki Krogerus wrote: > > > > > > Hi, > > > > > > > > > > > > On Fri, May 17, 2019 at 01:37:36PM +0300, Heikki Krogerus wrote: > > > > > > > On Tue, May 14, 2019 at 04:47:21PM +0800, Chunfeng Yun wrote: > > > > > > > > Add fwnode_usb_role_switch_get() to make easier to get > > > > > > > > usb_role_switch by fwnode which register it. > > > > > > > > It's useful when there is not device_connection registered > > > > > > > > between two drivers and only knows the fwnode which register > > > > > > > > usb_role_switch. > > > > > > > > > > > > > > > > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> > > > > > > > > Tested-by: Biju Das <biju.das@xxxxxxxxxxxxxx> > > > > > > > > > > > > > > Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> > > > > > > > > > > > > Hold on. I just noticed Rob's comment on patch 2/6, where he > > > > > > points out that you don't need to use device graph since the > > > > > > controller is the parent of the connector. Doesn't that mean you > > > > > > don't really need this API? > > > > > No, I still need it. > > > > > The change is about the way how to get fwnode; when use device > > > > > graph, get fwnode by of_graph_get_remote_node(); but now will get > > > > > fwnode by of_get_parent(); > > > > > > > > OK, I get that, but I'm still not convinced about if something like > > > > this function is needed at all. I also have concerns regarding how > > > > you are using the function. I'll explain in comment to the patch 5/6 in this > > series... > > > > > > FYI, Currently I am also using this api in my patch series. > > > https://patchwork.kernel.org/patch/10944637/ > > > > Yes, and I have the same question for you I jusb asked in comment I added > > to the patch 5/6 of this series. Why isn't usb_role_switch_get() enough? > > Currently no issue. It will work with this api as well, since the port node is part of controller node. > For eg:- > https://patchwork.kernel.org/patch/10944627/ > > However if any one adds port node inside the connector node, then this api may won't work as expected. > Currently I get below error > > [ 2.299703] OF: graph: no port node found in /soc/i2c@e6500000/hd3ss3220@47 > > For eg:- > > hd3ss3220@47 { > compatible = "ti,hd3ss3220"; > ... > .... > usb_con: connector { > .... > .... > port { > hd3ss3220_ep: endpoint@0 { > reg = <0>; > remote-endpoint = <&usb3peri_role_switch>; > }; > }; > }; > }; > > Regards, > Biju I tested 3 cases: case 1: connector { compatible = "linux,typeb-conn-gpio", "usb-b-connector"; label = "micro-USB"; type = "micro"; id-gpios = <&pio 12 GPIO_ACTIVE_HIGH>; vbus-supply = <&usb_p0_vbus>; port { bconn_ep: endpoint@0 { remote-endpoint = <&usb_role_sw>; }; }; }; &mtu3 { usb-role-switch; port { usb_role_sw: endpoint@0 { remote-endpoint = <&bconn_ep>; }; }; }; the driver of connector could use usb_role_switch_get(dev) to get mtu3's USB Role Switch. (dev is the device of connector) case 2: &mtu3 { usb-role-switch; connector { compatible = "linux,typeb-conn-gpio", "usb-b-connector"; label = "micro-USB"; type = "micro"; id-gpios = <&pio 12 GPIO_ACTIVE_HIGH>; vbus-supply = <&usb_p0_vbus>; }; }; the driver of connector using usb_role_switch_get(dev) failed to get mtu3's USB Role Switch. error log: #OF: graph: no port node found in /usb@11271000/connector this is because connector hasn't child node connected to remote endpoint which register USB Role Switch case 3: rsw_iddig: role_sw_iddig { compatible = "linux,typeb-conn-gpio"; status = "okay"; connector { compatible = "usb-b-connector"; label = "micro-USB"; type = "micro"; id-gpios = <&pio 12 GPIO_ACTIVE_HIGH>; vbus-supply = <&usb_p0_vbus>; port { bconn_ep: endpoint@0 { remote-endpoint = <&usb_role_sw>; }; }; }; }; &mtu3 { usb-role-switch; port { usb_role_sw: endpoint@0 { remote-endpoint = <&bconn_ep>; }; }; }; the driver of connector using usb_role_switch_get(dev) also failed to get mtu3's USB Role Switch. Because usb_role_switch_get() only search its child nodes (connector node), but not child's child (port node) This case is the same as Biju's Usually type-c is similar with case 3; the next version v6 of this series will use case 2 as Rob suggested, see [v5, 2/6] for case 2, will need the new API fwnode_usb_role_switch_get(); for case 3, use the new API, or need modify usb_role_switch_get();
