From patchwork Mon Aug 5 06:53:42 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Szyprowski X-Patchwork-Id: 2838549 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 57CDBBF535 for ; Mon, 5 Aug 2013 06:56:23 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 48B6A2017A for ; Mon, 5 Aug 2013 06:56:22 +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 EE24520165 for ; Mon, 5 Aug 2013 06:56:20 +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 1V6Ehc-0005G9-Co; Mon, 05 Aug 2013 06:55:37 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1V6EhL-0003jx-88; Mon, 05 Aug 2013 06:55:19 +0000 Received: from mailout2.samsung.com ([203.254.224.25]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1V6Egy-0003e9-N8 for linux-arm-kernel@lists.infradead.org; Mon, 05 Aug 2013 06:55:00 +0000 Received: from epcpsbgm2.samsung.com (epcpsbgm2 [203.254.230.27]) by mailout2.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MR100JAPPURLNB0@mailout2.samsung.com> for linux-arm-kernel@lists.infradead.org; Mon, 05 Aug 2013 15:54:28 +0900 (KST) X-AuditID: cbfee61b-b7efe6d000007b11-55-51ff4c2374eb Received: from epmmp1.local.host ( [203.254.227.16]) by epcpsbgm2.samsung.com (EPCPMTA) with SMTP id 8B.3E.31505.32C4FF15; Mon, 05 Aug 2013 15:54:27 +0900 (KST) Received: from localhost.localdomain ([106.116.147.30]) by mmp1.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0MR1001JGPTNTLG1@mmp1.samsung.com>; Mon, 05 Aug 2013 15:54:27 +0900 (KST) From: Marek Szyprowski To: linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, devicetree@vger.kernel.org Subject: [PATCH v4 2/4] drivers: of: add function to scan fdt nodes given by path Date: Mon, 05 Aug 2013 08:53:42 +0200 Message-id: <1375685624-12103-3-git-send-email-m.szyprowski@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1375685624-12103-1-git-send-email-m.szyprowski@samsung.com> References: <1375685624-12103-1-git-send-email-m.szyprowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrBLMWRmVeSWpSXmKPExsVy+t9jAV1ln/+BBkfPmln8nXSM3WL+kXOs Fq/ObGSzONv0ht1ie+cMdosvVx4yWWx6fI3VYu2Ru+wWG14eZLJYcLyF1eLPdDmLU9c/s1l8 //aNzeLv9k0sFofftLNarJ/xmsVBwOP3r0mMHpf7epk8ds66y+6xeUm9x+1/j5k9rpxoYvVY 9+cVk0f/XwOPvi2rGD1+vtTx+LxJLoA7issmJTUnsyy1SN8ugSvjz7N29oIzshWfti9iamC8 IN7FyMEhIWAiMe+WahcjJ5ApJnHh3nq2LkYuDiGBRYwSm458Zodw2pkkfmw4yw5SxSZgKNH1 tosNxBYRSJOYsWoDC4jNLNDGIvECwhYWCJZYfOYUWD2LgKrEj8OtYDavgIfEla9bWCAWK0jM mWQDYnIKeErcfJYJUiEEVLGg/yTbBEbeBYwMqxhFUwuSC4qT0nON9IoTc4tL89L1kvNzNzGC w/uZ9A7GVQ0WhxgFOBiVeHgV2P8HCrEmlhVX5h5ilOBgVhLhZe//GyjEm5JYWZValB9fVJqT WnyIUZqDRUmc92CrdaCQQHpiSWp2ampBahFMlomDU6qBcZ2acIzioztTJ3zuPWkedC+Y160m 1+bFkuSzAssmP77wQr34h2p6256TzPqmTBXGIYfk2Iwu9Zx+9Nle6Jkqn4e8zhaFIN/48gXL u/LK1YU47iRN7VZ+dHVqGpvrr0fvFO6sZZfJ+vReze3sA631G8sYXh1QKnG/YdEls9sk+tGW lbzpNQ8fKbEUZyQaajEXFScCAJHkYEBrAgAA X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130805_025457_449127_67AA49C5 X-CRM114-Status: GOOD ( 15.44 ) X-Spam-Score: -5.2 (-----) Cc: Laura Abbott , Arnd Bergmann , Tomasz Figa , Nishanth Peethambaran , Michal Nazarewicz , Grant Likely , Marc , Kyungmin Park , Sylwester Nawrocki , Olof Johansson , 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=-2.5 required=5.0 tests=BAYES_00,KHOP_BIG_TO_CC, RCVD_IN_DNSWL_MED,RP_MATCHES_RCVD,UNPARSEABLE_RELAY autolearn=ham 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 ealy boot before we can unflatten the tree. Signed-off-by: Marek Szyprowski Acked-by: Kyungmin Park --- 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 6bb7cf2..8d6e7e8 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -543,6 +543,82 @@ 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) { + st->depth += 1; + if (st->name[st->namelen] == 0) { + st->found = 1; + } else { + const char *next = st->name + st->namelen + 1; + const char *p = next; + while (*p != '/' && *p != 0) + p++; + st->name = next; + st->namelen = p - 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 && ret == -ENXIO) /* scan has been completed */ + return 0; + else + return -ENOENT; +} + #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..1151a7f 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 __init 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);