From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752781AbcBWLVS (ORCPT ); Tue, 23 Feb 2016 06:21:18 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:42540 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752495AbcBWLVP (ORCPT ); Tue, 23 Feb 2016 06:21:15 -0500 Message-ID: <56CC3ED9.5000101@huawei.com> Date: Tue, 23 Feb 2016 19:13:29 +0800 From: Shannon Zhao User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Rob Herring CC: "linux-arm-kernel@lists.infradead.org" , Ard Biesheuvel , Stefano Stabellini , , Catalin Marinas , Will Deacon , Mark Rutland , , "xen-devel@lists.xen.org" , "devicetree@vger.kernel.org" , "linux-efi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Ian Campbell , , Subject: Re: [PATCH v4 16/17] FDT: Add a helper to get specified name subnode References: <1454641552-12576-1-git-send-email-zhaoshenglong@huawei.com> <1454641552-12576-17-git-send-email-zhaoshenglong@huawei.com> In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.177.16.142] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.56CC409F.0023,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 8a0c6bf577ac9a9e818c7a295e9971ee Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016/2/9 13:04, Rob Herring wrote: > On Thu, Feb 4, 2016 at 9:05 PM, Shannon Zhao wrote: >> From: Shannon Zhao >> >> Sometimes it needs to check if there is a node in FDT by full path. > > I'm confused. Are you searching by full path or... > >> Introduce this helper to get the specified name subnode if it exists. > > name of sub node? > get the offset of sub node by specified name. > Either way, fdt_subnode_offset or fdt_path_offset doesn't work? > Ah，right，both of them should work. Does it need to add a wrapper in drivers/of/fdt.c for them or directly use them with the parameter initial_boot_params? Thanks, >> >> Signed-off-by: Shannon Zhao >> --- >> CC: Rob Herring >> --- >> drivers/of/fdt.c | 25 +++++++++++++++++++++++++ >> include/linux/of_fdt.h | 2 ++ >> 2 files changed, 27 insertions(+) >> >> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c >> index 655f79d..eacb188 100644 >> --- a/drivers/of/fdt.c >> +++ b/drivers/of/fdt.c >> @@ -645,6 +645,31 @@ int __init of_scan_flat_dt(int (*it)(unsigned long node, >> } >> >> /** >> + * of_get_flat_dt_subnode_by_name - get subnode of specified node by name >> + * >> + * @node: the parent node >> + * @uname: the name of subnode >> + * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none >> + */ >> + >> +int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) >> +{ >> + const void *blob = initial_boot_params; >> + int offset; >> + const char *pathp; >> + >> + for (offset = fdt_first_subnode(blob, node); >> + offset >= 0; >> + offset = fdt_next_subnode(blob, offset)) { >> + pathp = fdt_get_name(blob, offset, NULL); >> + if (strcmp(pathp, uname) == 0) >> + return offset; >> + } >> + >> + return -FDT_ERR_NOTFOUND; >> +} >> + >> +/** >> * of_get_flat_dt_root - find the root node in the flat blob >> */ >> unsigned long __init of_get_flat_dt_root(void) >> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h >> index df9ef38..fc28162 100644 >> --- a/include/linux/of_fdt.h >> +++ b/include/linux/of_fdt.h >> @@ -52,6 +52,8 @@ extern char __dtb_end[]; >> extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname, >> int depth, void *data), >> void *data); >> +extern int of_get_flat_dt_subnode_by_name(unsigned long node, >> + const char *uname); >> extern const void *of_get_flat_dt_prop(unsigned long node, const char *name, >> int *size); >> extern int of_flat_dt_is_compatible(unsigned long node, const char *name); >> -- >> 2.0.4 >> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe devicetree" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > . > -- Shannon