Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752409AbdCCT12 (ORCPT ); Fri, 3 Mar 2017 14:27:28 -0500 Received: from mail-lf0-f66.google.com ([209.85.215.66]:33537 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752161AbdCCT10 (ORCPT ); Fri, 3 Mar 2017 14:27:26 -0500 Subject: Re: [PATCH v17 2/3] usb: USB Type-C connector class To: Heikki Krogerus , Guenter Roeck References: <20170221142405.76299-1-heikki.krogerus@linux.intel.com> <20170221142405.76299-3-heikki.krogerus@linux.intel.com> <4b4bbffc-db02-3b54-04bc-e7de79b2d9ed@roeck-us.net> <07618170-d561-e7fe-08e0-91316c53d832@gmail.com> <20170303125940.GA6999@kuha.fi.intel.com> Cc: Greg KH , Felipe Balbi , Oliver Neukum , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org From: Mats Karrman Message-ID: <6ddb2eac-03d5-127e-df1e-ad189968e6b2@gmail.com> Date: Fri, 3 Mar 2017 20:27:08 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20170303125940.GA6999@kuha.fi.intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1522 Lines: 35 On 2017-03-03 13:59, Heikki Krogerus wrote: > On Fri, Mar 03, 2017 at 08:29:18AM +0100, Mats Karrman wrote: > .... > How would something like that sound to you guys? Complicated... Need to marinate on that for a while ;) >> My system is a bit different. It's an i.MX6 SoC with the typec phy and DP controller connected >> directly to the SoC and it's using DTB/OF. > Is this "DP controller" a controller that is capable of taking care of > the USB Power Delivery communication with the partner regarding > DisplayPort alternate mode? No, the "DP controller" just talks DP and knows nothing about Type-C or USB PD. It takes a video stream from the SoC and turns it into a DP link, set up and orchestrated by the corresponding driver. And all the driver needs from Type-C is the plugged in / interrupt / plugged out events. The analog switching between USB / safe / DP signal levels in the Type-C connector is, I think, best handled by the software doing the USB PD negotiation / Altmode handling (using some GPIOs). >> Do we need to further standardize attributes under (each) specific alternate mode to >> include things such as HPD for the DP mode? > I'm not completely sure what kind of system you have, but I would > imagine that if we had the bus, your DP controller driver would be the > port (and partner) alternate mode driver. The bus would bind you to > the typec phy. So, both the DP controller and the USB PD phy are I2C devices, and now I have to make them both attach to the AM bus as well? BR, Mats