From patchwork Fri Jan 17 15:44:14 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heiko Stuebner X-Patchwork-Id: 3505891 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id DE4AEC02DC for ; Fri, 17 Jan 2014 15:45:23 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EBDE820179 for ; Fri, 17 Jan 2014 15:45:18 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 79F4020172 for ; Fri, 17 Jan 2014 15:45:17 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1W4Bbc-0000JS-AY; Fri, 17 Jan 2014 15:45:12 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1W4BbZ-0005Kp-R1; Fri, 17 Jan 2014 15:45:09 +0000 Received: from gloria.sntech.de ([95.129.55.99]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1W4BbX-0005Id-9b for linux-arm-kernel@lists.infradead.org; Fri, 17 Jan 2014 15:45:08 +0000 Received: from ip545477c2.speed.planet.nl ([84.84.119.194] helo=phil.localnet) by gloria.sntech.de with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1W4Bb7-0007ZF-F3; Fri, 17 Jan 2014 16:44:41 +0100 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Mark Rutland , Pawel Moll Subject: [PATCH v2] of: add functions to count number of elements in a property Date: Fri, 17 Jan 2014 16:44:14 +0100 Message-ID: <1434798.oSb68sYmYT@phil> User-Agent: KMail/4.11.3 (Linux/3.11-2-amd64; KDE/4.11.3; x86_64; ; ) In-Reply-To: <20140117144456.GG19578@e106331-lin.cambridge.arm.com> References: <27256277.YJ687suYy5@phil> <3781679.27UF2dWtKL@phil> <20140117144456.GG19578@e106331-lin.cambridge.arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140117_104507_441858_6E38A595 X-CRM114-Status: GOOD ( 13.54 ) X-Spam-Score: -2.2 (--) Cc: "devicetree@vger.kernel.org" , Stephen Warren , Ian Campbell , "linux-kernel@vger.kernel.org" , "grant.likely@linaro.org" , "linux-arm-kernel@lists.infradead.org" X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Reviewed-by: Mark Rutland --- 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) +{ + 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); + return -EINVAL; + } + + return prop->length / elem_size; +} + +/** + * of_property_count_u8_elems - Count the number of u8 elements in a property + * + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * + * Search for a property in a device node and count the number of u8 elements + * in it. Returns number of elements on sucess, -EINVAL if the property does + * not exist or its length does not match a multiple of u8 and -ENODATA if the + * property does not have a value. + */ +int of_property_count_u8_elems(const struct device_node *np, + const char *propname) +{ + return of_count_property_elems_of_size(np, propname, sizeof(u8)); +} +EXPORT_SYMBOL_GPL(of_property_count_u8_elems); + +/** + * of_property_count_u16_elems - Count the number of u16 elements in a property + * + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * + * Search for a property in a device node and count the number of u16 elements + * in it. Returns number of elements on sucess, -EINVAL if the property does + * not exist or its length does not match a multiple of u16 and -ENODATA if the + * property does not have a value. + */ +int of_property_count_u16_elems(const struct device_node *np, + const char *propname) +{ + return of_count_property_elems_of_size(np, propname, sizeof(u16)); +} +EXPORT_SYMBOL_GPL(of_property_count_u16_elems); + +/** + * of_property_count_u32_elems - Count the number of u32 elements in a property + * + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * + * Search for a property in a device node and count the number of u32 elements + * in it. Returns number of elements on sucess, -EINVAL if the property does + * not exist or its length does not match a multiple of u32 and -ENODATA if the + * property does not have a value. + */ +int of_property_count_u32_elems(const struct device_node *np, + const char *propname) +{ + return of_count_property_elems_of_size(np, propname, sizeof(u32)); +} +EXPORT_SYMBOL_GPL(of_property_count_u32_elems); + +/** + * of_property_count_u64_elems - Count the number of u64 elements in a property + * + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * + * Search for a property in a device node and count the number of u64 elements + * in it. Returns number of elements on sucess, -EINVAL if the property does + * not exist or its length does not match a multiple of u64 and -ENODATA if the + * property does not have a value. + */ +int of_property_count_u64_elems(const struct device_node *np, + const char *propname) +{ + return of_count_property_elems_of_size(np, propname, sizeof(u64)); +} +EXPORT_SYMBOL_GPL(of_property_count_u64_elems); + +/** * of_find_property_value_of_size * * @np: device node from which the property value is to be read. diff --git a/include/linux/of.h b/include/linux/of.h index 276c546..06fe898 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -250,6 +250,14 @@ extern struct device_node *of_find_node_with_property( extern struct property *of_find_property(const struct device_node *np, const char *name, int *lenp); +extern int of_property_count_u8_elems(const struct device_node *np, + const char *propname); +extern int of_property_count_u16_elems(const struct device_node *np, + const char *propname); +extern int of_property_count_u32_elems(const struct device_node *np, + const char *propname); +extern int of_property_count_u64_elems(const struct device_node *np, + const char *propname); extern int of_property_read_u32_index(const struct device_node *np, const char *propname, u32 index, u32 *out_value); @@ -426,6 +434,30 @@ static inline struct device_node *of_find_compatible_node( return NULL; } +static inline int of_property_count_u8_elems(const struct device_node *np, + const char *propname) +{ + return -ENOSYS; +} + +static inline int of_property_count_u16_elems(const struct device_node *np, + const char *propname) +{ + return -ENOSYS; +} + +static inline int of_property_count_u32_elems(const struct device_node *np, + const char *propname) +{ + return -ENOSYS; +} + +static inline int of_property_count_u64_elems(const struct device_node *np, + const char *propname) +{ + return -ENOSYS; +} + static inline int of_property_read_u32_index(const struct device_node *np, const char *propname, u32 index, u32 *out_value) {