From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH v6 0/8] mfd: introduce a driver for LPSS devices on SPT Date: Mon, 27 Jul 2015 17:24:13 +0100 Message-ID: <20150727162413.GE21114@x1> References: <1438009443-55317-1-git-send-email-andriy.shevchenko@linux.intel.com> <20150727152733.GB21114@x1> <20150727160447.GL1577@lahna.fi.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-wi0-f178.google.com ([209.85.212.178]:33357 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752603AbbG0QYT (ORCPT ); Mon, 27 Jul 2015 12:24:19 -0400 Received: by wicmv11 with SMTP id mv11so146249437wic.0 for ; Mon, 27 Jul 2015 09:24:17 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20150727160447.GL1577@lahna.fi.intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Mika Westerberg Cc: 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 On Mon, 27 Jul 2015, Mika Westerberg wrote: > On Mon, Jul 27, 2015 at 04:27:33PM +0100, Lee Jones wrote: > > FAO Stephen Boyd, > >=20 > > > Stephen, can you, please, have a look into patch 8 regarding to c= lock name > > > matching and other stuff Lee asked? > >=20 > > Patch 8: > >=20 > > "Can you review the clock implementation please? It looks > > fragile to me as it relies heavily on device names constructe= d > > of MFD cell names and IDA numbers cat'ed together!" >=20 > Lee, can you suggest an alternative then? >=20 > Why we are doing it like this is that number of different LPSS device= s > changes from SoC to SoC. In addition to that the device (called "slic= e") > might have iDMA block or not. >=20 > Since the drivers in question (pxa2xx-spi, i2c-designware and 8250_dw= ) > use standard clk framework to request their clocks the Linux device m= ust > have clock registered which matches the device in advance. >=20 > Because we add the host controller device dynamically (from the MFD > driver) based on how many devices are actually present, we need someh= ow > 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 alo= ng > 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! --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html