Hi Chunfeng Yun, + Chen Yu Thanks for the feedback. > Subject: Re: [PATCH v5 4/6] usb: roles: add API to get usb_role_switch by > node > > Hi Heikki & Biju, > On Fri, 2019-05-24 at 15:44 +0300, Heikki Krogerus wrote: > > On Wed, May 22, 2019 at 02:57:33PM +0000, Biju Das wrote: > > > Hi Heikki, > > > > > > Thanks for the patch > > > > > > > Subject: Re: [PATCH v5 4/6] usb: roles: add API to get > > > > usb_role_switch by node > > > > > > > > On Wed, May 22, 2019 at 10:55:17AM +0000, Biju Das wrote: > > > > > Hi Chunfeng Yun, > > > > > > > > > > Thanks for the feedback. > > > > > > > > > > > Subject: RE: [PATCH v5 4/6] usb: roles: add API to get > > > > > > usb_role_switch by node > > > > > > > > > > > > Hi Biju, > > > > > > On Wed, 2019-05-22 at 08:05 +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 09:45:46AM +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 > > > > > > > > > > > > > > > > We need to understand why is that happening? > > > > > > > > > > > > > > > > > > > > > > Form the stack trace the parent node is > > > > > > > "parent_node=hd3ss3220@47" , > > > > > > instead of the "connector" node. > > > > > > > That is the reason for the above error. > > > > > > > > > > > > > > [ 2.442429] of_graph_get_next_endpoint.part.0+0x28/0x168 > > > > > > > [ 2.447889] of_fwnode_graph_get_next_endpoint+0x5c/0xb0 > > > > > > > [ 2.453267] fwnode_graph_get_next_endpoint+0x20/0x30 > > > > > > > [ 2.458374] device_connection_find_match+0x74/0x1a0 > > > > > > > [ 2.463399] usb_role_switch_get+0x20/0x28 > > > > > > > [ 2.467542] hd3ss3220_probe+0xc4/0x218 > > > > > > > > > > > > > > The use case is > > > > > > > > > > > > > > &i2c0 { > > > > > > > hd3ss3220@47 { > > > > > > > compatible = "ti,hd3ss3220"; > > > > > > > > > > > > > > usb_con: connector { > > > > > > > compatible = "usb-c-connector"; > > > > > > > port { > > > > > > > hd3ss3220_ep: endpoint { > > > > > > > remote-endpoint = > > > > > > <&usb3_role_switch>; > > > > > > > }; > > > > > > > }; > > > > > > > }; > > > > > > > }; > > > > > > > }; > > > > > > > > > > > > > > &usb3_peri0 { > > > > > > > companion = <&xhci0>; > > > > > > > usb-role-switch; > > > > > > > > > > > > > > port { > > > > > > > usb3_role_switch: endpoint { > > > > > > > remote-endpoint = <&hd3ss3220_ep>; > > > > > > > }; > > > > > > > }; > > > > > > > }; > > > > > > > > > > > > > > Q1) How do we modify the usb_role_switch_get() function to > > > > > > > search > > > > > > > Child(connector) and child's endpoint? > > > > > > How about firstly finding connector node in > > > > > > fwnode_graph_devcon_match(), then search each endpoint? > > > > > > > > > > I have done a quick prototyping with the changes you suggested > > > > > and it > > > > works. > > > > > > > > > > - struct fwnode_handle *ep; > > > > > + struct fwnode_handle *ep,*child,*tmp = fwnode; > > > > > > > > > > - fwnode_graph_for_each_endpoint(fwnode, ep) { > > > > > + child = fwnode_get_named_child_node(fwnode, "connector"); > > > > > + if (child) > > > > > + tmp = child; > > > > > + > > > > > + fwnode_graph_for_each_endpoint(tmp, ep) { > > > > > > > > > > Form the stack trace the parent node is "parent_node= connector" . > > > > > > > > > > [ 2.440922] of_graph_get_next_endpoint.part.0+0x28/0x168 > > > > > [ 2.446381] of_fwnode_graph_get_next_endpoint+0x5c/0xb0 > > > > > [ 2.451758] fwnode_graph_get_next_endpoint+0x20/0x30 > > > > > [ 2.456866] device_connection_find_match+0x84/0x1c0 > > > > > [ 2.461888] usb_role_switch_get+0x20/0x28 > > > > > > > > > > Heikki, > > > > > Are you ok with the above changes? > > > > > > > > Doesn't that mean that if we made fwnode_usb_role_switch_get() the > > > > way I proposed, there is no problem? You just find the "connector" > > > > child node in your driver, and pass that to > fwnode_usb_role_switch_get(): > > > > > > Yes, That is correct. > > > > > > > struct fwnode_handle *connector; > > > > ... > > > > connector = device_get_named_child_node(&client->dev, > "connector"); > > > > if (IS_ERR(connector)) > > > > <do something> > > > > > > > > hd3ss3220->role_sw = fwnode_usb_role_switch_get(connector); > > > > ... > > > > > > > > The difference is that instead of just converting a device node of > > > > an usb role switch to the usb role switch, it works just like > > > > usb_role_switch_get(), just taking fwnode instead of device entry as > parameter. > > > > > > > > I prepared the patches implementing fwnode_usb_role_switch_get() > > > > the way I though it needs to work for my own tests. Please find > > > > the patches attached. > > > > > > I have tested this patches and conform it works. > > > Do you plan to post this patches to ML? > > > > Could make them part of this series? > I'll do it, thanks Just a suggestion, Do you think, is it worth to add the below patch[1] also part of this series? So that we have all common patches in this series. "usb: roles: Introduce stubs for the exiting functions in role.h." [1] https://patchwork.kernel.org/patch/10909971/ Regards, Biju
