From patchwork Mon Aug 19 15:04:27 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Szyprowski X-Patchwork-Id: 2846538 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 9E129BF546 for ; Mon, 19 Aug 2013 15:06:23 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DDCE8201FF for ; Mon, 19 Aug 2013 15:06:18 +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 836A3201FE for ; Mon, 19 Aug 2013 15:06:17 +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 1VBR1l-0005W6-ER; Mon, 19 Aug 2013 15:05:53 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VBR1b-0000aK-5N; Mon, 19 Aug 2013 15:05:43 +0000 Received: from mailout4.samsung.com ([203.254.224.34]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VBR1M-0000WY-4s for linux-arm-kernel@lists.infradead.org; Mon, 19 Aug 2013 15:05:30 +0000 Received: from epcpsbgm1.samsung.com (epcpsbgm1 [203.254.230.26]) by mailout4.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MRS007AP9WGR1A0@mailout4.samsung.com> for linux-arm-kernel@lists.infradead.org; Tue, 20 Aug 2013 00:05:04 +0900 (KST) X-AuditID: cbfee61a-b7f196d000007dfa-ae-521234200856 Received: from epmmp2 ( [203.254.227.17]) by epcpsbgm1.samsung.com (EPCPMTA) with SMTP id C5.B2.32250.02432125; Tue, 20 Aug 2013 00:05:04 +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 <0MRS004QS9VPKP20@mmp2.samsung.com>; Tue, 20 Aug 2013 00:05:04 +0900 (KST) From: Marek Szyprowski To: linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, devicetree@vger.kernel.org Subject: [PATCH v6 2/4] drivers: of: add function to scan fdt nodes given by path Date: Mon, 19 Aug 2013 17:04:27 +0200 Message-id: <1376924669-28873-3-git-send-email-m.szyprowski@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1376924669-28873-1-git-send-email-m.szyprowski@samsung.com> References: <1376924669-28873-1-git-send-email-m.szyprowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmphkeLIzCtJLcpLzFFi42I5/e+xoK6CiVCQwYEmNYu/k46xW8w/co7V ov/NQlaLV2c2slm86e1gsTjb9IbdYnvnDHaLL1ceMllsenyN1WLtkbvsFhteHmSyWHr9IpPF guMtrBZ/pstZnLr+mc1iwvS1LBbfv31js/i7fROLxeE37UDjDraxWKyf8ZrFYtWuP4wOYh5r 5q1h9Pj9axKjx+vJExg9Lvf1MnnsnHWX3WPzknqP2/8eM3tcOdHE6rHuzysmj/6/Bh59W1Yx evx8qePxeZOcx8a5oQF8UVw2Kak5mWWpRfp2CVwZG36/ZSz4LVtxufMVcwPjd/EuRk4OCQET iXffNjNC2GISF+6tZwOxhQSmM0pc+KXXxcgFZLczSVy6+QYswSZgKNH1tgvMFhFIk5ixagML SBGzwBtWiRWXethBEsICwRJ3/vwCSnBwsAioSszcagZi8gp4SExsEwcxJQQUJOZMsgEp5hTw lNjWeZQJYq2HxL6nXxknMPIuYGRYxSiaWpBcUJyUnmuoV5yYW1yal66XnJ+7iREcN8+kdjCu bLA4xCjAwajEw9upJBQkxJpYVlyZe4hRgoNZSYT3KztQiDclsbIqtSg/vqg0J7X4EKM0B4uS OO+BVutAIYH0xJLU7NTUgtQimCwTB6dUA+NU5d2mwXNe+k7vYLvt6rmg5PGJePctDumKJn0H TWdur16e8Xztg+Xa27JdVpXHC8463Hp0Q3SpxiuV6u3+hv3hM9dPXBbp7bZkX/azWIe0Hdee l6YvOHyDsUdcWfnAotn6BW/sM/6r35hS/tKCf5Xcsf06uqvrVfmvVd+ddVesL17Jb0VxTrgS S3FGoqEWc1FxIgD57OO4lwIAAA== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130819_110528_477614_66D3822F X-CRM114-Status: GOOD ( 15.87 ) X-Spam-Score: -9.7 (---------) 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=-7.0 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 --- 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..585b1a6 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 && + 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..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 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);