Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752706AbaAQQyL (ORCPT ); Fri, 17 Jan 2014 11:54:11 -0500 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:36855 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752155AbaAQQyK (ORCPT ); Fri, 17 Jan 2014 11:54:10 -0500 Date: Fri, 17 Jan 2014 16:53:34 +0000 From: Mark Rutland To: Heiko =?utf-8?Q?St=C3=BCbner?= Cc: Pawel Moll , "linux-arm-kernel@lists.infradead.org" , "grant.likely@linaro.org" , Rob Herring , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Stephen Warren , Ian Campbell Subject: Re: [PATCH v2] of: add functions to count number of elements in a property Message-ID: <20140117165333.GH19578@e106331-lin.cambridge.arm.com> References: <27256277.YJ687suYy5@phil> <3781679.27UF2dWtKL@phil> <20140117144456.GG19578@e106331-lin.cambridge.arm.com> <1434798.oSb68sYmYT@phil> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1434798.oSb68sYmYT@phil> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 17, 2014 at 03:44:14PM +0000, Heiko Stübner wrote: > The need to know the number of array elements in a property is > a common pattern. To prevent duplication of open-coded implementations > add a helper static function that also centralises strict sanity > checking and DTB format details, as well as a set of wrapper functions > for u8, u16, u32 and u64. > > Suggested-by: Mark Rutland > Signed-off-by: Heiko Stuebner > --- > changes since v1: > address comments from Rob Herring and Mark Rutland: > - provide a helper and a set of wrappers for u8-u64 > - get rid of extra len variable, prop->length is enough > - include node name in error message > > drivers/of/base.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/of.h | 32 +++++++++++++++++ > 2 files changed, 130 insertions(+) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index f807d0e..b6e6d4a 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -862,6 +862,104 @@ struct device_node *of_find_node_by_phandle(phandle handle) > EXPORT_SYMBOL(of_find_node_by_phandle); > > /** > + * of_count_property_elems_of_size - Count the number of elements in a property > + * > + * @np: device node from which the property value is to be read. > + * @propname: name of the property to be searched. > + * @elem_size: size of the individual element > + */ > +static int of_count_property_elems_of_size(const struct device_node *np, > + const char *propname, int elem_size) As a minor nit, it would be nicer to have 'count' and 'property' switch places in the name (i.e. call this of_property_count_elems_of_size). That way it's concistent with the naming of the wrappers. > +{ > + struct property *prop = of_find_property(np, propname, NULL); > + > + if (!prop) > + return -EINVAL; > + if (!prop->value) > + return -ENODATA; > + > + if (prop->length % elem_size != 0) { > + pr_err("size of %s in node %s is not a multiple of %d\n", > + propname, np->name, elem_size); It would be nice to use np->full_name so you get the absolute path of the node -- it makes finding them easier later. Otherwise, the patch looks good to me, thanks for implementing it! With those changes: Reviewed-by: Mark Rutland Cheers, Mark. -- 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/