From patchwork Thu Jan 16 18:04:42 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heiko Stuebner X-Patchwork-Id: 3499951 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 037849F169 for ; Thu, 16 Jan 2014 18:06:14 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C9A3F200D9 for ; Thu, 16 Jan 2014 18:06:12 +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 586C020154 for ; Thu, 16 Jan 2014 18:06:11 +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 1W3rK8-00016d-Uy; Thu, 16 Jan 2014 18:05:49 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1W3rK3-0004pm-Ev; Thu, 16 Jan 2014 18:05:43 +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 1W3rJv-0004nH-Bb for linux-arm-kernel@lists.infradead.org; Thu, 16 Jan 2014 18:05:37 +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 1W3rJV-0003XA-3B; Thu, 16 Jan 2014 19:05:09 +0100 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Mark Rutland Subject: [PATCH] of: add function to count number of u32 elements in a property Date: Thu, 16 Jan 2014 19:04:42 +0100 Message-ID: <3781679.27UF2dWtKL@phil> User-Agent: KMail/4.11.3 (Linux/3.11-2-amd64; KDE/4.11.3; x86_64; ; ) In-Reply-To: <20140116124527.GD19578@e106331-lin.cambridge.arm.com> References: <27256277.YJ687suYy5@phil> <1669323.jqjZBfkRx4@phil> <20140116124527.GD19578@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-20140116_130535_562397_E5EF1783 X-CRM114-Status: GOOD ( 13.10 ) X-Spam-Score: -2.2 (--) Cc: "devicetree@vger.kernel.org" , Pawel Moll , Stephen Warren , Greg Kroah-Hartman , Ian Campbell , "linux-kernel@vger.kernel.org" , "arm@kernel.org" , Philipp Zabel , "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 function that also centralises strict sanity checking and DTB format details. Suggested-by: Mark Rutland Signed-off-by: Heiko Stuebner --- Hi Mark, did you mean it like this? I've tested it with the sram-reserve change and it made the part of the determining the number elements a lot nicer :-) drivers/of/base.c | 32 ++++++++++++++++++++++++++++++++ include/linux/of.h | 8 ++++++++ 2 files changed, 40 insertions(+) diff --git a/drivers/of/base.c b/drivers/of/base.c index f807d0e..0f40ea5 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -920,6 +920,38 @@ int of_property_read_u32_index(const struct device_node *np, EXPORT_SYMBOL_GPL(of_property_read_u32_index); /** + * of_property_count_u32_elems - Count the number of u32 values 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) +{ + int elem_size = sizeof(u32); + int len; + struct property *prop = of_find_property(np, propname, &len); + + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + + if (prop->length % elem_size != 0) { + pr_err("size of %s is not a multiple of u32\n", propname); + return -EINVAL; + } + + return len / elem_size; +} +EXPORT_SYMBOL_GPL(of_property_count_u32_elems); + +/** * of_property_read_u8_array - Find and read an array of u8 from a property. * * @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..5794942 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -253,6 +253,8 @@ extern struct property *of_find_property(const struct device_node *np, extern int of_property_read_u32_index(const struct device_node *np, const char *propname, u32 index, u32 *out_value); +extern int of_property_count_u32_elems(const struct device_node *np, + const char *propname); extern int of_property_read_u8_array(const struct device_node *np, const char *propname, u8 *out_values, size_t sz); extern int of_property_read_u16_array(const struct device_node *np, @@ -432,6 +434,12 @@ static inline int of_property_read_u32_index(const struct device_node *np, 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_read_u8_array(const struct device_node *np, const char *propname, u8 *out_values, size_t sz) {