From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752811AbaJTOzg (ORCPT ); Mon, 20 Oct 2014 10:55:36 -0400 Received: from mail-ie0-f173.google.com ([209.85.223.173]:39801 "EHLO mail-ie0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752672AbaJTOz3 (ORCPT ); Mon, 20 Oct 2014 10:55:29 -0400 MIME-Version: 1.0 In-Reply-To: <3213594.3tCDm06Aee@wuerfel> References: <2660541.BycO7TFnA2@vostro.rjw.lan> <20141018145520.6039FC40591@trevor.secretlab.ca> <7821406.D7i8JfDpzX@vostro.rjw.lan> <3213594.3tCDm06Aee@wuerfel> From: Grant Likely Date: Mon, 20 Oct 2014 16:55:08 +0200 X-Google-Sender-Auth: d6EkBjVvrd1Zb1cmUG20QAfEYBE Message-ID: Subject: Re: [PATCH v5 09/12] Driver core: Unified interface for firmware node properties To: Arnd Bergmann Cc: "Rafael J. Wysocki" , Linux Kernel Mailing List , Greg Kroah-Hartman , Mika Westerberg , ACPI Devel Maling List , Aaron Lu , "devicetree@vger.kernel.org" , Linus Walleij , Alexandre Courbot , Dmitry Torokhov , Bryan Wu , Darren Hart , Mark Rutland Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 20, 2014 at 4:19 PM, Arnd Bergmann wrote: > On Monday 20 October 2014 01:46:00 Rafael J. Wysocki wrote: >> >> > Something like: >> > >> > #define define_fwnode_accessors(__type, __devprop_type) \ >> > int device_property_read_##__type(struct device *dev, \ >> > const char *propname, __type *val) \ >> > { \ >> > if (IS_ENABLED(CONFIG_OF) && dev->of_node) \ >> > return of_property_read_##__type(dev->of_node, propname, val); \ >> > return acpi_dev_prop_read(ACPI_COMPANION(dev), propname, \ >> > __devprop_type, val); \ >> > } \ >> > int fwnode_property_read_##__type(struct fwnode_handle *fwnode, \ >> > const char *propname, __type *val) \ >> > { \ >> > if (IS_ENABLED(CONFIG_OF) && is_of_node(fwnode)) \ >> > return of_property_read_##__type(of_node(fwnode), propname, val); \ >> > else if (IS_ENABLED(CONFIG_ACPI) && is_acpi_node(fwnode)) \ >> > return acpi_dev_prop_read(acpi_node(fwnode), propname, \ >> > __devprop_type, val); \ >> > return -ENXIO; \ >> > } >> > >> > define_fwnode_accessors(u8, DEV_PROP_U8); >> > define_fwnode_accessors(u16, DEV_PROP_U16); >> > define_fwnode_accessors(u32, DEV_PROP_U32); >> > define_fwnode_accessors(u64, DEV_PROP_U64); >> > >> > That significantly reduces the code size for these things. >> >> So I was considering to do that, but eventually decided not to, because (1) >> adding kerneldoc comments to such things looks odd and (2) (which IMO is >> more important) this breaks LXR (for example, the thing at lxr.free-electrons.com >> that some people, including me in particular, occasionally use to check how things >> are defined). And even if you used the old good grep to look for a definition of >> fwnode_property_read_u8, say, this wouldn't work exactly as expected I'm afraid. > > Agreed, I'd also prefer your proposed code over Grant's macros. > >> I would very much like to retain the headers at least for this reason, if that's >> not a big deal. >> >> What I can do, however, is to use macros for generating the bodies of those >> functions. > > Yes, just don't do any concatenation to generate the names of the called > functions, i.e. > > return fwnode_call(of_property_read_u32, acpi_dev_prop_read, DEV_PROP_U32, node, propname, val); > > is better than > > return fwnode_call(u32, DEV_PROP_U32, node, propname, val); > > because it's easier to understand the call chain. Sounds reasonable. I've got no problem with that. g.