From patchwork Thu Jul 13 07:55:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 119640 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:a6b2:0:b0:3e4:2afc:c1 with SMTP id c18csp1677887vqm; Thu, 13 Jul 2023 01:38:46 -0700 (PDT) X-Google-Smtp-Source: APBJJlEBAEdsoOB98lfaobHbttzn6I7zo30/qICe7F+9zMajM8Zwne/NC3qLifsYzrFiSfDYLmwF X-Received: by 2002:a17:906:6b97:b0:990:8807:8f88 with SMTP id l23-20020a1709066b9700b0099088078f88mr724466ejr.55.1689237526654; Thu, 13 Jul 2023 01:38:46 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1689237526; cv=none; d=google.com; s=arc-20160816; b=JJZg0if9qj6EM75kIMb7Vy+3Pk4wYVCMzROzniMP2VlmaxrxXjAcWpBYbvVSF8YUGb LdqbTBbA+GYuUUoxaep+bNTGYP8JE8Umcv8xex+zsDQxxgAOIV0ZOZEB96T/agq4WKpx fkYCiYwPozWhTwizGKfs/OvL0gh9rRRILQl1hKaE9TdPzQ/7trTShidboe/CpUa4DC6v sH4/3YaVjpig9wXlG7bGdS3ABlCsBI49RllU7suPQAjdPh9etWpIBiTYaMHML1bxXs/5 m+QYx0jBZ3xgPU+YXnNU1prT3p+szlcST3vm2x5eVz8O5d4jFXR84N+Fb57jMUZKgxKt EAhA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=DfMfKPkntdHDW0sVYPIRqZGSzZ5pCxH34lQ77nS039A=; fh=ZBivFC5SWw0lWeQfkQzZMt8E06fgq2S9EtIfz3iJ8AM=; b=y4hITX+nsh+R32uUjWC8nzhiXntbV+HxkhmazJGgQ9mQI0jffTTEIeiUNnQz+zPfnS 58q2NmC2HjjbZIHmxC1JRzxZwaZV66nS5z5CiPfBuCMd6q51ZQcg5GfJf2e200nLSzcY LIBtYNCqsRiZH2chlkEUwdI/M9XhDIO8tTLS1tLZfc6kB4WfVlF6hxiMWTpMP9Zwr7SD NP64h2KDjE5Cea+8nbB+lzckg5SBnc9YfMOPIsBK2uAF2j5ESPkJA+xjoSj5DqCdyF5l YzWH+id10xAqQ1rFdf9ScYYawkIdaui3M0S4jRnNSczNfKVBYgs4z+3+Ua+6r95zasQb JbTA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@bootlin.com header.s=gm1 header.b=gIKQFqV7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=bootlin.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id qq17-20020a17090720d100b009938899a768si6410354ejb.530.2023.07.13.01.38.23; Thu, 13 Jul 2023 01:38:46 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@bootlin.com header.s=gm1 header.b=gIKQFqV7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=bootlin.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233028AbjGMHzS (ORCPT + 99 others); Thu, 13 Jul 2023 03:55:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232979AbjGMHzN (ORCPT ); Thu, 13 Jul 2023 03:55:13 -0400 Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C44D0170E for ; Thu, 13 Jul 2023 00:55:11 -0700 (PDT) Received: by mail.gandi.net (Postfix) with ESMTPSA id CAF30C0014; Thu, 13 Jul 2023 07:55:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1689234910; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DfMfKPkntdHDW0sVYPIRqZGSzZ5pCxH34lQ77nS039A=; b=gIKQFqV7w/iP9I4Dxnqq19gV3bMnRitqzd8uLwTUvSVgYuR3h2mWDjQHaPXvJ9J72LG8v8 n//3ZSg1WJMETukogrqvaRl0Lkx7H6Jj5/MAvhrIm8cgY6uTguPJMFV8UhSwq/7hHaH7xG kB0Rlk43+eq6I+0/ljLRd5lJ58loAfkb3VAz5Hvob5qdeZAcQF5PqRIcnxI+/4wou22jHp sdkDlpqp7Z8TwJTEkPu8gd5Mb+/bCMUVPGwBmRuVZ7K/D4Q+5Dc4C5ebrBPMayZniP+Trm Gd6GQh/+yQK22QZZq/1BV4DDxiuqFvxUodc3HHBC0WLpsAjZm5k2jokXeUuCvw== From: Miquel Raynal To: Srinivas Kandagatla , Greg Kroah-Hartman , Cc: Thomas Petazzoni , Robert Marko , Luka Perkov , Miquel Raynal Subject: [PATCH RESEND v5 1/3] ABI: sysfs-nvmem-cells: Expose cells through sysfs Date: Thu, 13 Jul 2023 09:55:05 +0200 Message-Id: <20230713075508.485072-2-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230713075508.485072-1-miquel.raynal@bootlin.com> References: <20230713075508.485072-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 X-GND-Sasl: miquel.raynal@bootlin.com X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_PASS,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1771293928834119488 X-GMAIL-MSGID: 1771293928834119488 The binary content of nvmem devices is available to the user so in the easiest cases, finding the content of a cell is rather easy as it is just a matter of looking at a known and fixed offset. However, nvmem layouts have been recently introduced to cope with more advanced situations, where the offset and size of the cells is not known in advance or is dynamic. When using layouts, more advanced parsers are used by the kernel in order to give direct access to the content of each cell regardless of their position/size in the underlying device, but these information were not accessible to the user. By exposing the nvmem cells to the user through a dedicated cell/ folder containing one file per cell, we provide a straightforward access to useful user information without the need for re-writing a userland parser. Content of nvmem cells is usually: product names, manufacturing date, MAC addresses, etc, Signed-off-by: Miquel Raynal Reviewed-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-nvmem-cells | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-nvmem-cells diff --git a/Documentation/ABI/testing/sysfs-nvmem-cells b/Documentation/ABI/testing/sysfs-nvmem-cells new file mode 100644 index 000000000000..641a7d7dad76 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-nvmem-cells @@ -0,0 +1,19 @@ +What: /sys/bus/nvmem/devices/.../cells/ +Date: May 2023 +KernelVersion: 6.5 +Contact: Miquel Raynal +Description: + The cells/ folder contains one file per cell exposed by + the nvmem device. The name of the file is the cell name. + The length of the file is the size of the cell (when + known). The content of the file is the binary content of + the cell (may sometimes be ASCII, likely without + trailing character). + Note: This file is only present if CONFIG_NVMEM_SYSFS + is enabled + + ex:: + + hexdump -C /sys/bus/nvmem/devices/1-00563/cells/product-name + 00000000 54 4e 34 38 4d 2d 50 2d 44 4e |TN48M-P-DN| + 0000000a From patchwork Thu Jul 13 07:55:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 119608 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:a6b2:0:b0:3e4:2afc:c1 with SMTP id c18csp1661156vqm; Thu, 13 Jul 2023 00:59:59 -0700 (PDT) X-Google-Smtp-Source: APBJJlE9cFTXJPAe1d4L33RdZG+LyBjkvi3LbYkWE+4I2/Sg+VeTDBf2HHBv138a5InWck9MwYDE X-Received: by 2002:a05:6a20:3943:b0:118:e70:6f7d with SMTP id r3-20020a056a20394300b001180e706f7dmr354406pzg.10.1689235198743; Thu, 13 Jul 2023 00:59:58 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1689235198; cv=none; d=google.com; s=arc-20160816; b=djhRPGP0XvSiPlnMkA+Vi7VlTe3S7SxeIctZ1Rz0hRx/F8dyEqRoMrJYaxSIIhz8sR 1Lt+xEvVNdw4B246nPhlzbQIt2EZeRLX0ayLZzHa44pPW2K/Zuqs2kpJektqTWSAdDe0 pnXWcBLpmNgVHWxWkKOVCNNG5N5mmDizpVs5l5Inda3W6dzGciNt6jsQmJjP1opK44hH vFf486Cf3WVb/UnDtg4So7+ewxKob/TUN4HAUAwpOaZ3o+2MUmip5LnJm+6P4P5COAlc vehYhtBysvuDtZ8XNABKnrnO0DXgfGFCPjGrWO3ia7tHw/Ebo6OU8QUiebOiF1Yj848K 3NCg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=un3Uwaotmlox+IhpuLnflkjcgnz89/YG1Do8CcofnC8=; fh=ZBivFC5SWw0lWeQfkQzZMt8E06fgq2S9EtIfz3iJ8AM=; b=X4i7nYEnsw6r5/UL28j6reSdFhVU3/JgO3nrF5EshYSl4+/u8Bt78M6zyza9wcrgXl J1FyDYeCZnMafHrf59MLF8dwhEQonDWv3agQM1pO00zbTygnpVV3JUQ7XvYyLUR8iM2X OqD+xo2LClY9g5FL6opQgWiusyrYNRG2qh1GIOCnIkA4ZK2fSg1lfEYFvtT4vaL3twvn WVHvzo+sYH0XDCHSBBNCkcOtXiNUq5NntKbp0fyaQIRmZpeCpuYxEVHqzOv+IzsCOe9i wTSSKeZC/MpuLVZmHdipr02aLFHzdC292UNlK6P6EE+5kpEvSRy+8Z14m8yKTS/ABDRV uVhA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@bootlin.com header.s=gm1 header.b=J+NPr684; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=bootlin.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id c9-20020a170903234900b001b81fe65fa3si5021670plh.569.2023.07.13.00.59.46; Thu, 13 Jul 2023 00:59:58 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@bootlin.com header.s=gm1 header.b=J+NPr684; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=bootlin.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233074AbjGMHzX (ORCPT + 99 others); Thu, 13 Jul 2023 03:55:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232989AbjGMHzN (ORCPT ); Thu, 13 Jul 2023 03:55:13 -0400 Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::226]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5C16173F for ; Thu, 13 Jul 2023 00:55:12 -0700 (PDT) Received: by mail.gandi.net (Postfix) with ESMTPSA id C353AC000E; Thu, 13 Jul 2023 07:55:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1689234911; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=un3Uwaotmlox+IhpuLnflkjcgnz89/YG1Do8CcofnC8=; b=J+NPr6840Zv8RDcu2FXpfHhLZ5nHQ624tV8tSiofImoFSKQ/Z5At/i0OTkkgPQDFxvONsz smeH/ugpM6pV/kVghzzP32aKqpLzg3rlcf3wcmpXNvCOXTN/YiV1FeNyNODTNc7xUv2/os WVVDWU5da5C1xOmpgezsCPXnh0+Z5F/tCjoDe/pjX0wn+86KwkSXnTlOBzzuNu1PbEB9hl vcSj3VLD7k70tHcVJlqziaLwojCnZCU3NnplnGW/Ikr5rOSzy1CS4cTGTJnhc/hEKbDSrE iYdU9jZpiFnPBifvQI2ym0F/jtIAxBdjE9JGwYvLKpU7u3BxkT0yMdaHacn8sQ== From: Miquel Raynal To: Srinivas Kandagatla , Greg Kroah-Hartman , Cc: Thomas Petazzoni , Robert Marko , Luka Perkov , Miquel Raynal Subject: [PATCH RESEND v5 2/3] nvmem: core: Create all cells before adding the nvmem device Date: Thu, 13 Jul 2023 09:55:06 +0200 Message-Id: <20230713075508.485072-3-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230713075508.485072-1-miquel.raynal@bootlin.com> References: <20230713075508.485072-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 X-GND-Sasl: miquel.raynal@bootlin.com X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1771291487887010341 X-GMAIL-MSGID: 1771291487887010341 Let's pack all the cells creation in one place, so they are all created before we add the nvmem device. Signed-off-by: Miquel Raynal --- drivers/nvmem/core.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 3f8c7718412b..48659106a1e2 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -998,12 +998,6 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) if (rval) goto err_remove_cells; - dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); - - rval = device_add(&nvmem->dev); - if (rval) - goto err_remove_cells; - rval = nvmem_add_cells_from_fixed_layout(nvmem); if (rval) goto err_remove_cells; @@ -1012,6 +1006,12 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) if (rval) goto err_remove_cells; + dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); + + rval = device_add(&nvmem->dev); + if (rval) + goto err_remove_cells; + blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem); return nvmem; From patchwork Thu Jul 13 07:55:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 119622 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:a6b2:0:b0:3e4:2afc:c1 with SMTP id c18csp1669750vqm; Thu, 13 Jul 2023 01:18:18 -0700 (PDT) X-Google-Smtp-Source: APBJJlFP3tXsalFLHrVkpjF+QhE9k4JntzwXIBOJffZgKH8sWVZYUJnKBHMEM42bl4PIExX7l24i X-Received: by 2002:a17:906:d8:b0:992:2f67:cd34 with SMTP id 24-20020a17090600d800b009922f67cd34mr1814523eji.22.1689236297904; Thu, 13 Jul 2023 01:18:17 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1689236297; cv=none; d=google.com; s=arc-20160816; b=J3L5Dofs75dmswlAchZ+6vj8N9DPcUMBwBgk3yMG6pk0s8VhzE9sPsCPhaOUkvDfts 3PsvhKuYpK++iL/NhdpbqYUicVvQPBKfMi+f8A+0SyEudJU5JVbYoPwqCn9u6OJA9bjI DlF9yEe6fr9a9udQyo1H8Ng2Pvu58+ZrjGFA8kypgGCV5yPJQKIV60FHj9zsyAwWnfSk HVgGBHKv18gg9DqVuvDN9mqiVCsO2SKsuOj1Cf8gNLRRiUKU8wGxv4oewM3Kx64rhHqL zLyNc1wwrGy4eRMcG8ppFiHEXlDeCWyKkcisLICEHw3/Z6GKLe8cLEnP/p95e/os+RoX 2MZw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=RrYa81jVjDuF0o+K2o6QuVvcpzCkZHcHCjfMG1eLeRQ=; fh=ZBivFC5SWw0lWeQfkQzZMt8E06fgq2S9EtIfz3iJ8AM=; b=UicB/MSWk4w6+Mg5LGSuBrTKmVyoCg325xp06mHrf3zdVd+bPExFU2R6mbSkkHkOjF 6BE5RpHn7xctqKnUH/IohIeyPnNY929t/fkZLFBU9YlfTtpH8tPDds0f23WMB7B10OEC HprINzwnR09MKxXeyGeIe4ecLjFN0F8E9uB2NVta/h4sBNfGzdtnuy9B7lzoAlauteWx iVVhajtQP79i3Ipz5Ojs41jL5yXUtlRtQ6caVE98Jc6Xov+HaStRV04ZI9G6ROFWVJeU ewQ/ExNmALSqF56zZGun5TLvHnuIhvlcD4sJpLUVJxGHLvSCyaemiJgsn6VbvUaZwCiG 608w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@bootlin.com header.s=gm1 header.b=iLRncOLW; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=bootlin.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id lh11-20020a170906f8cb00b0098718971f52si6362049ejb.87.2023.07.13.01.17.53; Thu, 13 Jul 2023 01:18:17 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@bootlin.com header.s=gm1 header.b=iLRncOLW; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=bootlin.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233050AbjGMHz2 (ORCPT + 99 others); Thu, 13 Jul 2023 03:55:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233008AbjGMHzP (ORCPT ); Thu, 13 Jul 2023 03:55:15 -0400 Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::226]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8766C10FA for ; Thu, 13 Jul 2023 00:55:14 -0700 (PDT) Received: by mail.gandi.net (Postfix) with ESMTPSA id 84B76C000B; Thu, 13 Jul 2023 07:55:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1689234913; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RrYa81jVjDuF0o+K2o6QuVvcpzCkZHcHCjfMG1eLeRQ=; b=iLRncOLWdNl3B9tqqtbmNllAd6sz39Cw7tjmi+aFV5uTDKA74L65FZ0OUKfzr22ZLNVaht QA8lDLh0zXdECcElfB/R76uHgzFTRSM0rcWxMakA0d49LP3D2jUEur1/Pdb+QNtZQU0wSe oRl0/yNLvQzZOfmfiqwE1Y74NNi5ESisVrMvLdoYjIDaEVzVpXGG/IdS7clMPbY5+sRSaH Km/WADOkbpYbUoP8VhyPKf2XIziJBZtCe47JzQDriteuThnmGwiPdgCmc+V1lhJ0AI3+V+ u1JChlc4GWedht7u9Kimwg4TlPR59p9+Q3DWu4gcqQ2EiRPoGx9lHHuANQS5WQ== From: Miquel Raynal To: Srinivas Kandagatla , Greg Kroah-Hartman , Cc: Thomas Petazzoni , Robert Marko , Luka Perkov , Miquel Raynal Subject: [PATCH RESEND v5 3/3] nvmem: core: Expose cells through sysfs Date: Thu, 13 Jul 2023 09:55:08 +0200 Message-Id: <20230713075508.485072-5-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230713075508.485072-1-miquel.raynal@bootlin.com> References: <20230713075508.485072-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 X-GND-Sasl: miquel.raynal@bootlin.com X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1771292640209529340 X-GMAIL-MSGID: 1771292640209529340 The binary content of nvmem devices is available to the user so in the easiest cases, finding the content of a cell is rather easy as it is just a matter of looking at a known and fixed offset. However, nvmem layouts have been recently introduced to cope with more advanced situations, where the offset and size of the cells is not known in advance or is dynamic. When using layouts, more advanced parsers are used by the kernel in order to give direct access to the content of each cell, regardless of its position/size in the underlying device. Unfortunately, these information are not accessible by users, unless by fully re-implementing the parser logic in userland. Let's expose the cells and their content through sysfs to avoid these situations. Of course the relevant NVMEM sysfs Kconfig option must be enabled for this support to be available. Not all nvmem devices expose cells. Indeed, the .bin_attrs attribute group member will be filled at runtime only when relevant and will remain empty otherwise. In this case, as the cells attribute group will be empty, it will not lead to any additional folder/file creation. Exposed cells are read-only. There is, in practice, everything in the core to support a write path, but as I don't see any need for that, I prefer to keep the interface simple (and probably safer). The interface is documented as being in the "testing" state which means we can later add a write attribute if though relevant. There is one limitation though: if a layout is built as a module but is not properly installed in the system and loaded manually with insmod while the nvmem device driver was built-in, the cells won't appear in sysfs. But if done like that, the cells won't be usable by the built-in kernel drivers anyway. Signed-off-by: Miquel Raynal Reviewed-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 101 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 48659106a1e2..6c04a9cf6919 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -325,6 +325,43 @@ static umode_t nvmem_bin_attr_is_visible(struct kobject *kobj, return nvmem_bin_attr_get_umode(nvmem); } +static struct nvmem_cell *nvmem_create_cell(struct nvmem_cell_entry *entry, + const char *id, int index); + +static ssize_t nvmem_cell_attr_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *attr, char *buf, + loff_t pos, size_t count) +{ + struct nvmem_cell_entry *entry; + struct nvmem_cell *cell = NULL; + size_t cell_sz, read_len; + void *content; + + entry = attr->private; + cell = nvmem_create_cell(entry, entry->name, 0); + if (IS_ERR(cell)) + return PTR_ERR(cell); + + if (!cell) + return -EINVAL; + + content = nvmem_cell_read(cell, &cell_sz); + if (IS_ERR(content)) { + read_len = PTR_ERR(content); + goto destroy_cell; + } + + read_len = min_t(unsigned int, cell_sz - pos, count); + memcpy(buf, content + pos, read_len); + kfree(content); + +destroy_cell: + kfree_const(cell->id); + kfree(cell); + + return read_len; +} + /* default read/write permissions */ static struct bin_attribute bin_attr_rw_nvmem = { .attr = { @@ -346,8 +383,14 @@ static const struct attribute_group nvmem_bin_group = { .is_bin_visible = nvmem_bin_attr_is_visible, }; +/* Cell attributes will be dynamically allocated */ +static struct attribute_group nvmem_cells_group = { + .name = "cells", +}; + static const struct attribute_group *nvmem_dev_groups[] = { &nvmem_bin_group, + &nvmem_cells_group, NULL, }; @@ -406,6 +449,58 @@ static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem, device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); } +static int nvmem_populate_sysfs_cells(struct nvmem_device *nvmem) +{ + struct bin_attribute **cells_attrs, *attrs; + struct nvmem_cell_entry *entry; + unsigned int ncells = 0, i = 0; + int ret = 0; + + mutex_lock(&nvmem_mutex); + + if (list_empty(&nvmem->cells)) + goto unlock_mutex; + + /* Allocate an array of attributes with a sentinel */ + ncells = list_count_nodes(&nvmem->cells); + cells_attrs = devm_kcalloc(&nvmem->dev, ncells + 1, + sizeof(struct bin_attribute *), GFP_KERNEL); + if (!cells_attrs) { + ret = -ENOMEM; + goto unlock_mutex; + } + + attrs = devm_kcalloc(&nvmem->dev, ncells, sizeof(struct bin_attribute), GFP_KERNEL); + if (!attrs) { + ret = -ENOMEM; + goto unlock_mutex; + } + + /* Initialize each attribute to take the name and size of the cell */ + list_for_each_entry(entry, &nvmem->cells, node) { + sysfs_bin_attr_init(&attrs[i]); + attrs[i].attr.name = devm_kstrdup(&nvmem->dev, entry->name, GFP_KERNEL); + attrs[i].attr.mode = 0444; + attrs[i].size = entry->bytes; + attrs[i].read = &nvmem_cell_attr_read; + attrs[i].private = entry; + if (!attrs[i].attr.name) { + ret = -ENOMEM; + goto unlock_mutex; + } + + cells_attrs[i] = &attrs[i]; + i++; + } + + nvmem_cells_group.bin_attrs = cells_attrs; + +unlock_mutex: + mutex_unlock(&nvmem_mutex); + + return ret; +} + #else /* CONFIG_NVMEM_SYSFS */ static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem, @@ -1006,6 +1101,12 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) if (rval) goto err_remove_cells; +#ifdef CONFIG_NVMEM_SYSFS + rval = nvmem_populate_sysfs_cells(nvmem); + if (rval) + goto err_remove_cells; +#endif + dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name); rval = device_add(&nvmem->dev);