From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH v6 0/8] mfd: introduce a driver for LPSS devices on SPT Date: Mon, 27 Jul 2015 23:48:54 +0200 Message-ID: <4701357.XbJcg3OWzk@vostro.rjw.lan> References: <1438009443-55317-1-git-send-email-andriy.shevchenko@linux.intel.com> <20150727160447.GL1577@lahna.fi.intel.com> <20150727162413.GE21114@x1> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <20150727162413.GE21114@x1> Sender: linux-acpi-owner@vger.kernel.org To: Lee Jones Cc: Mika Westerberg , Andy Shevchenko , linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, Greg Kroah-Hartman , Vinod Koul , linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, Heikki Krogerus , Jarkko Nikula , "Wysocki, Rafael J" , mturquette@baylibre.com, sboyd@codeaurora.org List-Id: linux-pm@vger.kernel.org On Monday, July 27, 2015 05:24:13 PM Lee Jones wrote: > On Mon, 27 Jul 2015, Mika Westerberg wrote: > > > On Mon, Jul 27, 2015 at 04:27:33PM +0100, Lee Jones wrote: > > > FAO Stephen Boyd, > > > > > > > Stephen, can you, please, have a look into patch 8 regarding to clock name > > > > matching and other stuff Lee asked? > > > > > > Patch 8: > > > > > > "Can you review the clock implementation please? It looks > > > fragile to me as it relies heavily on device names constructed > > > of MFD cell names and IDA numbers cat'ed together!" > > > > Lee, can you suggest an alternative then? > > > > Why we are doing it like this is that number of different LPSS devices > > changes from SoC to SoC. In addition to that the device (called "slice") > > might have iDMA block or not. > > > > Since the drivers in question (pxa2xx-spi, i2c-designware and 8250_dw) > > use standard clk framework to request their clocks the Linux device must > > have clock registered which matches the device in advance. > > > > Because we add the host controller device dynamically (from the MFD > > driver) based on how many devices are actually present, we need somehow > > predict what would be the correct name and instance number for that > > device to get the clock for it. That's the reason we use IDA here along > > with the cell name (or driver name). > > I'm sure there are perfectly viable reasons for you doing this. And I > don't know the CCF well enough to know whether it's the best idea or > not, or else I would have made a suggestion rather than waiting all > this time. > > It's for this reason that I needed Mike (now Stephen) to take a look > and give me either an Ack, to say it's the best solution, or to > provide a better alternative. > > Until that happens, I'm stuck! Well, what if we had no one at hand to review that code? Would that mean it would not be applicable forever? Thanks, Rafael