From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com ([134.134.136.20]:36582 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751286AbeEUNMp (ORCPT ); Mon, 21 May 2018 09:12:45 -0400 Date: Mon, 21 May 2018 16:12:39 +0300 From: Heikki Krogerus Subject: Re: [PATCH v5 05/14] usb: typec: add API to get typec basic port power and data config Message-ID: <20180521131239.GB10677@kuha.fi.intel.com> References: <1525307094-27402-6-git-send-email-jun.li@nxp.com> <74e1c164-1652-75f4-409c-bd1c214bda4d@gmail.com> <20180516122527.GC11469@kuha.fi.intel.com> <33d02e76-bdf2-be50-68ec-9d520acdbe82@gmail.com> <20180517123506.GF11469@kuha.fi.intel.com> <20180517142420.GH11469@kuha.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: devicetree-owner@vger.kernel.org To: Jun Li Cc: Mats Karrman , "robh+dt@kernel.org" , "gregkh@linuxfoundation.org" , "linux@roeck-us.net" , "a.hajda@samsung.com" , "cw00.choi@samsung.com" , "shufan_lee@richtek.com" , Peter Chen , "gsomlo@gmail.com" , "devicetree@vger.kernel.org" , "linux-usb@vger.kernel.org" , dl-linux-imx List-ID: Hi Jun, Sorry for the delay. On Thu, May 17, 2018 at 02:41:31PM +0000, Jun Li wrote: > Hi > > -----Original Message----- > > From: Heikki Krogerus [mailto:heikki.krogerus@linux.intel.com] > > Sent: 2018??5??17?? 22:24 > > To: Jun Li > > Cc: Mats Karrman ; robh+dt@kernel.org; > > gregkh@linuxfoundation.org; linux@roeck-us.net; a.hajda@samsung.com; > > cw00.choi@samsung.com; shufan_lee@richtek.com; Peter Chen > > ; gsomlo@gmail.com; devicetree@vger.kernel.org; > > linux-usb@vger.kernel.org; dl-linux-imx > > Subject: Re: [PATCH v5 05/14] usb: typec: add API to get typec basic port power > > and data config > > > > On Thu, May 17, 2018 at 02:05:41PM +0000, Jun Li wrote: > > > Hi Heikki, > > > > > > > > I reread this patch and tried to see it more in the context of the > > > > > other patches and the existing code. The naming of the existing > > > > > string tables doesn't help in getting this right, however I have a proposal: > > > > > > > > > > typec_find_port_power_role() to get to TYPEC_PORT_SRC/SNK/DRP > > > > > typec_find_port_data_role() to get to TYPEC_PORT_DFP/UFP/DRD > > > > > typec_find_power_role() to get to TYPEC_SINK/SOURCE > > > > > > > > > > and sometime, if the use should arise > > > > > > > > > > typec_find_data_role() to get to TYPEC_DEVICE/HOST > > > > > > > > > > I think it is fairly comprehensible, *_port_* concerns a > > > > > capability and without *_port_* it is an actual state. Plus it > > > > > matches the names of the constants. > > > > > > > > Well, there are now four things to consider: > > > > > > > > 1) the roles (power and data) the port is capable of supporting > > > > 2) Try.SRC and Try.SNK, i.e. the preferred role > > > > 3) the current roles > > > > 4) the role(s) the user want's to limit the use of a port with DRP > > > > ports > > > > > > > > The last one I don't know if it's relevant with these functions. > > > > It's not information that we would get for example from firmware. > > > > > > > > I also don't think we need to use these functions with the current > > > > roles the port is in. > > > > > > > > If the preferred role is "sink" or "source", so just like the power > > > > role, we don't need separate function for it here. > > > > > > > > So isn't two functions all we need here: one for the power and one > > > > for data role? > > > > > > Take power as an example, can we use one function to only look up > > > typec_port_types[]? as capability(typec_port_type) and > > > state(typec_role) are different enum, and the allowed strings are different. > > > > > > static const char * const typec_roles[] = { > > > [TYPEC_SINK] = "sink", > > > [TYPEC_SOURCE] = "source", > > > }; > > > > > > static const char * const typec_port_types[] = { > > > [TYPEC_PORT_SRC] = "source", > > > [TYPEC_PORT_SNK] = "sink", > > > [TYPEC_PORT_DRP] = "dual", > > > }; > > > > Where out side the class code we need to convert the current role, the "state", > > with these functions? > > Currently, the only call site is getting the preferred power role from firmware. My point was that if we used enum typec_port_type with the prefered role, we could use the helper for power role with prefered role. But never mind. Thanks, -- heikki