From patchwork Mon Aug 26 14:39:17 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Szyprowski X-Patchwork-Id: 2849609 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 B5A999F271 for ; Mon, 26 Aug 2013 14:41:07 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 55AFA20150 for ; Mon, 26 Aug 2013 14:41:06 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C98F820142 for ; Mon, 26 Aug 2013 14:41:04 +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 1VDxyD-0001Py-Gj; Mon, 26 Aug 2013 14:40:41 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VDxy6-0000oe-AK; Mon, 26 Aug 2013 14:40:34 +0000 Received: from mailout1.samsung.com ([203.254.224.24]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VDxxh-0000kT-Pb for linux-arm-kernel@lists.infradead.org; Mon, 26 Aug 2013 14:40:13 +0000 Received: from epcpsbgm1.samsung.com (epcpsbgm1 [203.254.230.26]) by mailout1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MS5008YP7EKD410@mailout1.samsung.com> for linux-arm-kernel@lists.infradead.org; Mon, 26 Aug 2013 23:39:56 +0900 (KST) X-AuditID: cbfee61a-b7f7a6d00000235f-fe-521b68bcfe01 Received: from epmmp2 ( [203.254.227.17]) by epcpsbgm1.samsung.com (EPCPMTA) with SMTP id 68.C4.09055.CB86B125; Mon, 26 Aug 2013 23:39:56 +0900 (KST) Received: from localhost.localdomain ([106.116.147.30]) by mmp2.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0MS50074S7DMCL50@mmp2.samsung.com>; Mon, 26 Aug 2013 23:39:56 +0900 (KST) From: Marek Szyprowski To: linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, devicetree@vger.kernel.org Subject: [PATCH v7 2/4] drivers: of: add function to scan fdt nodes given by path Date: Mon, 26 Aug 2013 16:39:17 +0200 Message-id: <1377527959-5080-3-git-send-email-m.szyprowski@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1377527959-5080-1-git-send-email-m.szyprowski@samsung.com> References: <1377527959-5080-1-git-send-email-m.szyprowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmphkeLIzCtJLcpLzFFi42I5/e+xoO6eDOkgg+WX5Sz+TjrGbjH/yDlW i/43C1ktXp3ZyGbxpreDxeJs0xt2i+2dM9gtvlx5yGSx6fE1Vou1R+6yW2x4eZDJYun1i0wW C463sFr8mS5ncer6ZzaLCdPXslh8//aNzeLv9k0sFofftAONO9jGYrF+xmsWi1W7/jA6iHms mbeG0eP3r0mMHq8nT2D0uNzXy+Sxc9Zddo/NS+o9bv97zOxx5UQTq8e6P6+YPPr/Gnj0bVnF 6PHzpY7H501yHhvnhgbwRXHZpKTmZJalFunbJXBl9Oy+wFawXq7iwKQLrA2MyyS6GDk4JARM JD7eteli5AQyxSQu3FvP1sXIxSEkMJ1R4vChGawQTjuTxNpjs9lBqtgEDCW63naxgdgiAmkS M1ZtYAEpYhZ4wyqx4lIPO8hUYYFgiU33M0BqWARUJY7+aAWr5xVwlzj5+zErxGIFiTmTwBZz CnhI3Dk2gxEkLARU0tqqOYGRdwEjwypG0dSC5ILipPRcQ73ixNzi0rx0veT83E2M4Lh5JrWD cWWDxSFGAQ5GJR7ewAKpICHWxLLiytxDjBIczEoivByp0kFCvCmJlVWpRfnxRaU5qcWHGKU5 WJTEeQ+0WgcKCaQnlqRmp6YWpBbBZJk4OKUaGBcdElYzWML/KHTD6+a/P7miF1k+T/5+j+Pn P/2rHY9kg/xk+Kv/6UbFqyZlaBcq971wTnC+v5/nYj33xbSzkUzX598/6HTxwKXq1qLpJmxn +pNW6kwrPLFi2bJEzwxBp0qW+Zu5PGN1qtyfhl10nL9L4NstKwbum53HozO/eAQUSrgLdqx9 osRSnJFoqMVcVJwIAGuIHBuXAgAA X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130826_104011_571279_9184786A X-CRM114-Status: GOOD ( 15.15 ) X-Spam-Score: -9.3 (---------) Cc: Mark Rutland , Laura Abbott , Pawel Moll , Arnd Bergmann , Stephen Warren , Tomasz Figa , Tomasz Figa , Michal Nazarewicz , Grant Likely , Marc , Kyungmin Park , Sylwester Nawrocki , Kumar Gala , Olof Johansson , Ian Campbell , Nishanth Peethambaran , Sascha Hauer , Marek Szyprowski 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: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-6.6 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 Add a function to scan the flattened device-tree starting from the node given by the path. It is used to extract information (like reserved memory), which is required on early boot before we can unflatten the tree. Signed-off-by: Marek Szyprowski Acked-by: Michal Nazarewicz Acked-by: Tomasz Figa Reviewed-by: Rob Herring Acked-by: Grant Likely --- drivers/of/fdt.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_fdt.h | 3 ++ 2 files changed, 79 insertions(+) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index b10ba00..4fb06f3 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -545,6 +545,82 @@ int __init of_flat_dt_match(unsigned long node, const char *const *compat) return of_fdt_match(initial_boot_params, node, compat); } +struct fdt_scan_status { + const char *name; + int namelen; + int depth; + int found; + int (*iterator)(unsigned long node, const char *uname, int depth, void *data); + void *data; +}; + +/** + * fdt_scan_node_by_path - iterator for of_scan_flat_dt_by_path function + */ +static int __init fdt_scan_node_by_path(unsigned long node, const char *uname, + int depth, void *data) +{ + struct fdt_scan_status *st = data; + + /* + * if scan at the requested fdt node has been completed, + * return -ENXIO to abort further scanning + */ + if (depth <= st->depth) + return -ENXIO; + + /* requested fdt node has been found, so call iterator function */ + if (st->found) + return st->iterator(node, uname, depth, st->data); + + /* check if scanning automata is entering next level of fdt nodes */ + if (depth == st->depth + 1 && + strncmp(st->name, uname, st->namelen) == 0 && + uname[st->namelen] == 0) { + st->depth += 1; + if (st->name[st->namelen] == 0) { + st->found = 1; + } else { + const char *next = st->name + st->namelen + 1; + st->name = next; + st->namelen = strcspn(next, "/"); + } + return 0; + } + + /* scan next fdt node */ + return 0; +} + +/** + * of_scan_flat_dt_by_path - scan flattened tree blob and call callback on each + * child of the given path. + * @path: path to start searching for children + * @it: callback function + * @data: context data pointer + * + * This function is used to scan the flattened device-tree starting from the + * node given by path. It is used to extract information (like reserved + * memory), which is required on ealy boot before we can unflatten the tree. + */ +int __init of_scan_flat_dt_by_path(const char *path, + int (*it)(unsigned long node, const char *name, int depth, void *data), + void *data) +{ + struct fdt_scan_status st = {path, 0, -1, 0, it, data}; + int ret = 0; + + if (initial_boot_params) + ret = of_scan_flat_dt(fdt_scan_node_by_path, &st); + + if (!st.found) + return -ENOENT; + else if (ret == -ENXIO) /* scan has been completed */ + return 0; + else + return ret; +} + #ifdef CONFIG_BLK_DEV_INITRD /** * early_init_dt_check_for_initrd - Decode initrd location from flat tree diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index ed136ad..19f26f8 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -90,6 +90,9 @@ extern void *of_get_flat_dt_prop(unsigned long node, const char *name, extern int of_flat_dt_is_compatible(unsigned long node, const char *name); extern int of_flat_dt_match(unsigned long node, const char *const *matches); extern unsigned long of_get_flat_dt_root(void); +extern int of_scan_flat_dt_by_path(const char *path, + int (*it)(unsigned long node, const char *name, int depth, void *data), + void *data); extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, int depth, void *data);