From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baruch Siach Subject: Re: [PATCH 2/2] phy: driver for Conexant Digicolor internal USB PHY Date: Tue, 31 Mar 2015 21:42:53 +0300 Message-ID: <20150331184253.GR12479@tarshish> References: <6284a7672647d46100281959552f9787f98bb552.1427430989.git.baruch@tkos.co.il> <4a9ceb0a240d49dd6a68d50c78f85d310d4b932f.1427430989.git.baruch@tkos.co.il> <201503281633.02801.marex@denx.de> <20150331113448.GN12479@tarshish> <551ABCBE.3030005@ti.com> <20150331154119.GO12479@tarshish> <551AC160.8060202@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <551AC160.8060202@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Kishon Vijay Abraham I Cc: Marek Vasut , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org Hi Kishon, On Tue, Mar 31, 2015 at 09:16:40PM +0530, Kishon Vijay Abraham I wrote: > On Tuesday 31 March 2015 09:11 PM, Baruch Siach wrote: > >On Tue, Mar 31, 2015 at 08:56:54PM +0530, Kishon Vijay Abraham I wrote: > >>On Tuesday 31 March 2015 05:04 PM, Baruch Siach wrote: > >>>On Sat, Mar 28, 2015 at 04:33:02PM +0100, Marek Vasut wrote: > >>>>On Friday, March 27, 2015 at 05:36:29 AM, Baruch Siach wrote: > >>>>>Add a driver for the USB PHY on the Conexant CX92755 SoC, from the > >>>>>Digicolor series of SoCs. The PHY is connected to the on-chip chipidea > >>>>>usb2 host. > >>>>> > >>>>>The hardware is somewhat similar to the phy-mxs-usb.c usb_phy, but it is > >>>>>different enough to merit its own driver. Also, this driver uses the > >>>>>generic phy infrastructure. > >>>> > >>>>the register set looks very similar to MXS one indeed. How is it different > >>>>please ? > >>> > >>>Almost of the bits that are defined in the MXS USBPHY_CTRL register are not > >>>defined in the Digicolor one. Some have different meaning, and some are > >>>reserved. OTOH, the Digicolor USBPHY_CTRL register uses all bits in the 1-13 > >>>range. Also, the Digicolor phy does not have anatop registers. > >> > >>I think we should try adding support for this in the same driver. > > > >The only code that can actually be shared between the driver is the two lines > >usb_phy .on_connect callback routine. The init sequence that takes most of the > >digicolor driver is totally different. Using a single driver for both PHYs > >does not make much sense, IMHO. > > > >Besides, phy-mxs-usb.c uses the deprecated usb_phy framework. So we first need > >to port this driver to the generic phy framework. > > Doesn't your driver also use the usb_phy framework? My driver uses usb_phy only for the .notify_connect/.notify_disconnect callbacks, since there is no comparable functionality in the generic phy framework. But it doesn't make this driver any more similar to phy-mxs-usb. My point is that merging the drives would require migrating phy-mxs-usb to generic phy. But this is just an added complication. The main reason I think the drivers should be separate is because they have very little in common, regardless of the framework they are using. baruch -- http://baruch.siach.name/blog/ ~. .~ Tk Open Systems =}------------------------------------------------ooO--U--Ooo------------{= - baruch@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -