From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 05 Jul 2022 14:00:55 +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 1o8hEa-006UPW-C6 for lore@lore.pengutronix.de; Tue, 05 Jul 2022 14:00:55 +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 1o8hEc-0005Y9-5G for lore@pengutronix.de; Tue, 05 Jul 2022 14:00:55 +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:From:In-Reply-To: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/78gxmCljlj6kZN4LRwD5MyLcpxc4GasVqwiA4sNW78=; b=Q1JtbitqSMVKeNm3Nk65AutRo/ xrw5dLCFi83qN5cqd2kzybYIiIywnkC7OzoxJTEZlPHdv0pGdKxkhaDKt57e6c6I4I+aZfb7I89/v 3TRSWfUW1CPX6+eDcL2/s7A7wX1kIr13EE0CexW+qZSgAskgLHMQ61AzT4uPYqx7eDBHVlYHHWvws +W0H0Wic1k9U8/47t36rNhvJZ+JeIwRJyV/FX6tyZ5FkPKrLSsTyBff4sEShj/fTgJ4PvKhRSLw6K 2QZR4x74SZrELR7mxrppkoJLVHPOLD8+uen6TWEhPyYnk3QMSMvtSmAbPMB1/cykViwEAsVEcC7q0 nNgyecaw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8hDI-00HZqv-7s; Tue, 05 Jul 2022 11:59:32 +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 1o8hDB-00HZpB-3c for barebox@lists.infradead.org; Tue, 05 Jul 2022 11:59:26 +0000 Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1o8hD9-000546-LL; Tue, 05 Jul 2022 13:59:23 +0200 Received: from sha by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1o8hD9-0000XK-CH; Tue, 05 Jul 2022 13:59:23 +0200 Date: Tue, 5 Jul 2022 13:59:23 +0200 To: Ahmad Fatoum Cc: barebox@lists.infradead.org Message-ID: <20220705115923.GG5208@pengutronix.de> References: <20220705115538.3248502-1-a.fatoum@pengutronix.de> <20220705115538.3248502-2-a.fatoum@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220705115538.3248502-2-a.fatoum@pengutronix.de> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain User-Agent: Mutt/1.10.1 (2018-07-13) From: Sascha Hauer X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220705_045925_208881_B39D46FF X-CRM114-Status: GOOD ( 35.09 ) 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=-4.2 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: Re: [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) On Tue, Jul 05, 2022 at 01:55:37PM +0200, Ahmad Fatoum wrote: > 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; Forgot to mention: We have devpath_to_name() which does exactly that. Also I merged your last series with that change, so unless you have made other changes we should be fine. Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |