From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 05 Jul 2022 13:57:41 +0200 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1o8hBS-006UHK-2d for lore@lore.pengutronix.de; Tue, 05 Jul 2022 13:57:41 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1o8hBT-0004jL-EC for lore@pengutronix.de; Tue, 05 Jul 2022 13:57:40 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=X1xHnJLEA0wqNsCkxg8aWiOfbEyf/ZRkdWJg93qtoWA=; b=aF++Uw7nDvTTK9Uo7/jnFTm0d9 HoiK1Lakjpw2lBqw4yyZzySC9MS7H91etyFsmf3CeLOEhcmsS0k/cAnA2UI6CH8tAJR+p4iWSoOCv cXdVLSEzdjFYkqlba7dvQaRo2ozNNfZU5vrDJGxEbfOT8ZkwCFdsUMzEBv/rkiRI0yzPx88DzziYT lh2wwOMpAov5LEqWPvB8xfU8Wr6taoHBrPkQc2TH1wNXsah0qel1wrRn3VogATbJhXcNNY6dzKGNg 4btsWz6J5PkWorgcTO/lRWb0gHskErWQ2CmtmbXhCgSDtbxrDVwWEbFEOVpO75Xp7guwZp/YrjCLL 1ZLZR+Kg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8hA2-00HYSL-Ty; Tue, 05 Jul 2022 11:56:11 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8h9i-00HYMy-2P for barebox@lists.infradead.org; Tue, 05 Jul 2022 11:55:51 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1o8h9Y-0004Cz-Rh; Tue, 05 Jul 2022 13:55:40 +0200 Received: from [2a0a:edc0:0:1101:1d::ac] (helo=dude04.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtp (Exim 4.94.2) (envelope-from ) id 1o8h9U-004YSx-Ht; Tue, 05 Jul 2022 13:55:40 +0200 Received: from afa by dude04.red.stw.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1o8h9X-00Diug-3t; Tue, 05 Jul 2022 13:55:39 +0200 From: Ahmad Fatoum To: barebox@lists.infradead.org Cc: Ahmad Fatoum Date: Tue, 5 Jul 2022 13:55:37 +0200 Message-Id: <20220705115538.3248502-2-a.fatoum@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220705115538.3248502-1-a.fatoum@pengutronix.de> References: <20220705115538.3248502-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220705_045550_194538_923EF853 X-CRM114-Status: GOOD ( 20.59 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.ext.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-4.1 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_LOW,SPF_HELO_NONE,SPF_NONE, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH v2 2/3] commands: implement devlookup to find device behind device file X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.ext.pengutronix.de) For OF-enabled platforms with aliases, device file naming is pretty much solved: If there is mmc2 = &something, then we have a mmc2 device and a /dev/mmc2 device file. For other platforms like x86, EFI-provided devices are harder to get ahold of. Add a command to make this straight-forward to do in scripts. The main use of this is probably to access parameters like nt_signature or guid: devlookup /dev/disk0 guid This would print to console, but we have no output capture yet, so add an optional -v VARIABLE parameter as well to allow easy use from scripts. Signed-off-by: Ahmad Fatoum --- v1 -> v2: - fix typo in commit message (Michael) - accept cdev without /dev/ prefix (Sascha) - early exit on cdev without dev, e.g. /dev/zero --- commands/Kconfig | 13 ++++++++ commands/Makefile | 1 + commands/devlookup.c | 78 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 92 insertions(+) create mode 100644 commands/devlookup.c diff --git a/commands/Kconfig b/commands/Kconfig index c5505321cfd9..037b41155695 100644 --- a/commands/Kconfig +++ b/commands/Kconfig @@ -75,6 +75,19 @@ config CMD_DEVINFO If called with a device path being the argument, devinfo shows more default information about this device and its parameters. +config CMD_DEVLOOKUP + tristate + prompt "devlookup" + help + Look up device behind device file and its parameters + + devlookup [-v VAR] /dev/DEVICE [parameter] + + Detects the device behind a device file and outputs it, + unless a second argument is given. In that case the device + parameter with that name is looked up. Specifying -v VARIABLE + will write output to VARIABLE instead of printing it. + config CMD_DEVUNBIND tristate prompt "devunbind" diff --git a/commands/Makefile b/commands/Makefile index b3b7bafe6b64..0aae8893d696 100644 --- a/commands/Makefile +++ b/commands/Makefile @@ -110,6 +110,7 @@ obj-$(CONFIG_CMD_DETECT) += detect.o obj-$(CONFIG_CMD_BOOT) += boot.o obj-$(CONFIG_CMD_DEVINFO) += devinfo.o obj-$(CONFIG_CMD_DEVUNBIND) += devunbind.o +obj-$(CONFIG_CMD_DEVLOOKUP) += devlookup.o obj-$(CONFIG_CMD_DRVINFO) += drvinfo.o obj-$(CONFIG_CMD_READF) += readf.o obj-$(CONFIG_CMD_MENUTREE) += menutree.o diff --git a/commands/devlookup.c b/commands/devlookup.c new file mode 100644 index 000000000000..c361d5b58860 --- /dev/null +++ b/commands/devlookup.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include +#include +#include +#include +#include +#include +#include +#include + +static int report(const char *variable, const char *val) +{ + if (!val) + return -(errno ?: EINVAL); + + if (variable) + return setenv(variable, val); + + printf("%s\n", val); + return 0; +} + +static int do_devlookup(int argc, char *argv[]) +{ + const char *variable = NULL, *devicefile, *paramname; + struct cdev *cdev; + int opt; + + while ((opt = getopt(argc, argv, "v:")) > 0) { + switch(opt) { + case 'v': + variable = optarg; + break; + } + } + + if (argc - optind == 0 || argc - optind > 2) + return COMMAND_ERROR_USAGE; + + devicefile = argv[optind]; + paramname = argv[optind+1]; + + if (strstarts(devicefile, "/dev/")) + devicefile += sizeof("/dev/") - 1; + + cdev = cdev_by_name(devicefile); + if (!cdev) { + printf("devlookup: cdev %s not found\n", devicefile); + return -ENOENT; + } + + if (!cdev->dev) { + printf("devlookup: cdev %s not associated with a device\n", devicefile); + return -ENODEV; + } + + if (paramname) + return report(variable, dev_get_param(cdev->dev, paramname)); + + return report(variable, dev_name(cdev->dev)); +} + +BAREBOX_CMD_HELP_START(devlookup) +BAREBOX_CMD_HELP_TEXT("Detects the device behind a device file and outputs it,") +BAREBOX_CMD_HELP_TEXT("unless a second argument is given. In that case the device") +BAREBOX_CMD_HELP_TEXT("parameter with that name is looked up. Specifying -v VARIABLE") +BAREBOX_CMD_HELP_TEXT("will write output to VARIABLE instead of printing it") +BAREBOX_CMD_HELP_END + +BAREBOX_CMD_START(devlookup) + .cmd = do_devlookup, + BAREBOX_CMD_DESC("look up device behind device file and its parameters") + BAREBOX_CMD_OPTS("[-v VAR] /dev/DEVICE [parameter]") + BAREBOX_CMD_GROUP(CMD_GRP_SCRIPT) + BAREBOX_CMD_HELP(cmd_devlookup_help) +BAREBOX_CMD_END + -- 2.30.2