Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754015Ab2B0Qmz (ORCPT ); Mon, 27 Feb 2012 11:42:55 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:53778 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753654Ab2B0Qmx (ORCPT ); Mon, 27 Feb 2012 11:42:53 -0500 Date: Mon, 27 Feb 2012 11:42:52 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Arnd Bergmann cc: Wolfram Sang , , Roland Stigge , Greg Kroah-Hartman , , , Subject: Re: [PATCH v2] USB: Support for LPC32xx SoC In-Reply-To: <201202271403.16893.arnd@arndb.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2889 Lines: 66 On Mon, 27 Feb 2012, Arnd Bergmann wrote: > > > > A little progress has been made already. We just received a submission > > > > for a "generic" platform bus glue file that will be able to take over > > > > the jobs of several of the existiing files. If anyone wants to take > > > > this further I won't object, but I don't plan to work on it myself > > > > soon. > > > > > > Ok, good to know. The approach of a generic glue is exactly what I > > > was going to suggest. As we get to ARM platforms that are currently > > > using PLATFORM_DRIVER, I will then ask people to convert the ohci > > > glue to use that generic glue instead of adding another *_DRIVER > > > macro to ohci/ehci. > > > > The problem is that several platforms have highly specialized needs > > that can't sanely be handled in a single generic driver. Although a > > lot of drivers can be converted over, not all of them will. > > Can you give an example? We have recently converted the sdhci mmc drivers > in a similar way, and we have the libata drivers that have always worked > in this manner. Look at ehci-tegra.c. It has numerous non-generic overrides, such as tegra_ehci_hub_control(). It also has support for two clocks and a transceiver. > > > I'm not sure about what we should do for lpc32xx. Is that > > > generic glue going into v3.4? > > > > That's up to Greg. At the moment it isn't used by anything, and unless > > an existing driver can be converted over I'd guess it's not likely to > > get merged right away. > > Where is that patch? Maybe I can help out by converting the PCI > variants of ohci and ehci to the generic glue, because they are > easy to test. http://marc.info/?l=linux-usb&m=132986573930143&w=2 and the following two messages in the linux-usb mailing list. > > At the moment, switching the pnx4008 driver to use the generic bus glue > > doesn't look easy. The generic code doesn't know anything about i2c. > > Maybe I misunderstood what the generic bus glue does then, because I > would not expect that it should know about i2c ;-) > > I would think the generic bus glue would be a very simple library that > just exports the various symbols that are defined in ohci-hcd.c and > used in the bus specific driver so that the driver can be a separate > module. Is it something different from that? Quite different. What you just described is ohci-hcd.c itself -- except that it doesn't export the necessary symbols. The generic driver, as you'll see when you read the patch, includes generic versions of the various routines that a bus glue file has to provide (probe, remove, initialize, and so on). Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/