From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH 7/7] OF/ACPI/I2C: Add generic match function for the aforementioned systems Date: Fri, 6 Jun 2014 13:36:53 +0100 Message-ID: <20140606123653.GP24240@lee--X1> References: <1401883796-17841-1-git-send-email-lee.jones@linaro.org> <1401883796-17841-8-git-send-email-lee.jones@linaro.org> <20140605103009.85BE4C40A4D@trevor.secretlab.ca> <20140605103709.GE19550@lee--X1> <20140605155509.GH24240@lee--X1> <20140606102446.GK2520@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <20140606102446.GK2520-GFdadSzt00ze9xe1eoZjHA@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Brown Cc: Grant Likely , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , Linux Kernel Mailing List , Wolfram Sang , Linux I2C , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Linus Walleij List-Id: devicetree@vger.kernel.org On Fri, 06 Jun 2014, Mark Brown wrote: > On Thu, Jun 05, 2014 at 04:55:09PM +0100, Lee Jones wrote: > > On Thu, 05 Jun 2014, Grant Likely wrote: >=20 > > > I still think the way to do it is to emulate the missing i2c_devi= ce_id > > > when calling the drivers .probe() hook by having a temporary copy= on > > > the stack and filling it with data from the OF or ACPI table.... >=20 > > That's the opposite of what I'm trying to achieve. I'm trying to g= et > > rid of unused i2c_device_id tables, rather than reinforce their > > mandatory existence. I think an i2c_of_match_device() with knowled= ge > > of how to match via pure DT principles (of_node/compatible) and a > > fall-back, which is able to match on a provided of_device_id table > > alone i.e. without the requirement of an existing of_node. >=20 > > I've also been mulling over the idea of removing the second probe() > > parameter, as suggested by Wolfram. However, this has quite deep > > ramifications which would require a great deal of driver adaptions. >=20 > If you're going to do that another option is to refactor the probe() > function to take the driver_data as an argument and then have the cor= e > pass that from whatever table it matched from rather than the entire > i2c_device_id structure. That way the driver just needs to supply al= l > the ID tables mapping binding information to whatever it needs and th= e > core can pass in the driver data from whatever table it matched again= st. Unfortunately this means we're back to the aforementioned typing issue. For struct {platform,i2c,spi,acpi,etc}_device_id the driver data is a kernel ulong but the of_device_id's driver data attribute is a void*. I've just started work on a migration over to a new probe(). I don't think it's all that much work, but if there are any objections I'd prefer to hear them now rather than waste any time. I propose to convert a couple of drivers, one which doesn't use the driver_data and one that does, but is DT only and send them for review. See if Wolfram et. al like the method. --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog