From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 05 Jul 2022 14:06:06 +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 1o8hJa-006Uai-T2 for lore@lore.pengutronix.de; Tue, 05 Jul 2022 14:06:06 +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 1o8hJc-0007Ag-W7 for lore@pengutronix.de; Tue, 05 Jul 2022 14:06:05 +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: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=m/58FHvo+t1ufG9IIYN3vYFfjVxQgtf9+ygUTRAKcuM=; b=IwcKlun5QDTsvm9DJHy1qF9I2h efD9D1lxQmiNAqgu4osflHuOarXfm2U2awZlQlC9o2zao57L9PjeDHH7dwzagXeHq/d4jsKIe0lcq 6K/dxnr3oWm9G1D2jlY52/Zt0GHubhJtwElTiyDzYZ6G3i2zsIc20riHSEn2JeAukV0tgryAnV97g tOE+fPtfz689gm1hSrO66J3jSzAUqjy/2DB2LEHX6foe7x2PYfJd6APQfe+OIiWeU7RZul3ROkR2s tuvsYj5h4pxXdxPWoySObqlmPd7oOoySvTbi3Z1D16Nlatoj+6C28WjMB9P5Kz3NwOXUCZUO8lRX3 KDHFTtyA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8hIJ-0001BV-Fq; Tue, 05 Jul 2022 12:04:43 +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 1o8hIE-00019q-IG for barebox@lists.infradead.org; Tue, 05 Jul 2022 12:04:40 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1o8hIC-0006kg-HJ; Tue, 05 Jul 2022 14:04:36 +0200 Message-ID: <13c7f54e-86c5-3b95-ccd5-d35cd6bf174e@pengutronix.de> Date: Tue, 5 Jul 2022 14:04:36 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Content-Language: en-US To: Sascha Hauer Cc: barebox@lists.infradead.org References: <20220705115538.3248502-1-a.fatoum@pengutronix.de> <20220705115538.3248502-2-a.fatoum@pengutronix.de> <20220705115923.GG5208@pengutronix.de> From: Ahmad Fatoum In-Reply-To: <20220705115923.GG5208@pengutronix.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220705_050438_654756_1A86E17B X-CRM114-Status: GOOD ( 28.77 ) 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,NICE_REPLY_A,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 05.07.22 13:59, Sascha Hauer wrote: > 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. Yes, I added a check below for deviceless cdevs, which otherwise would crash on devlookup /dev/full Do you need me to create a v3 or will you fix this up? Cheers, Ahmad > > 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 |