From nobody Sat Apr 4 07:48:53 2026 Received: from FR5P281CU006.outbound.protection.outlook.com (mail-germanywestcentralazon11022079.outbound.protection.outlook.com [40.107.149.79]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2786F36EAB7; Fri, 20 Mar 2026 08:10:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.149.79 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773994215; cv=fail; b=JOjkbZRW+n/0BndnTGVpR0lAOoJrBnsPLnw8yNFA64VB9u7T6IxHxY+IpHwBNwzJ0jd8gm6YDZk7HyrJUlW70WO1nK/g/GQ5qARzFzJmW2WwNKjn336+h6mwuU7cAp3WK6Brk+Z2kcBSmkfmNRXrFNto12mD19z7P61DS68kSmY= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773994215; c=relaxed/simple; bh=0ViqLVH291F9X4kYTh5kYocimwQvgfHtYAQDJyjD63c=; h=From:To:Cc:Subject:Date:Message-ID:Content-Type:MIME-Version; b=Zq/Hn3R+DtnLhBRvkm6FJYDuh8ZigkQt4mXO4OMuZcvVDcjaqLF6gmdxN8N3BCc9F+lQIlXXetImKjUafaOrhjEbM59WCX9NV3/6gY0JIwv1dhUgnWKfEiwz3F94aXRGSKdVw/LLoY8Tgi0XQq2drKcmZGTtfwYVUkXThemnWQE= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=arctic.de; spf=pass smtp.mailfrom=arctic.de; dkim=pass (2048-bit key) header.d=Arctic.de header.i=@Arctic.de header.b=f2nj5eYX; arc=fail smtp.client-ip=40.107.149.79 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=arctic.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arctic.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Arctic.de header.i=@Arctic.de header.b="f2nj5eYX" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=ZAg98W7cZwx2vGJXcXFNIpiPXIPkM3TrTeP3XYkQNAsOeoMRQh2rfGhfBUdDep2InGjQjLsDBkSh6ELmBbc2EAydykpid2YIlHfz0bJ5Ph7O97Ds6tbSnzTG4nGVr+9q5ubaIwMzvbsKOPZIdMHEH5hYmKW03YdLto/VEEc/FZgzeyC6TCuTsS60p6FlM8acu5v+uqPptOc63zC5wiFxXLTs/FSFg4jR8yiBlBx6Vt3XsxLSy0oJ0HAcOCzq36Gdmb9qWIsH3YlJyoouYFewt96yacsvEvCm/KXlEsqjbLGyr+nItVS4CpqEPVzTpHvzVPKBlpi+ptHvaA3BNcC2vA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=0zWtBUSm5e7I9A/LWX37+NKXs9HHxRxBa9yqiA8yLOc=; b=HMtXFYh96BmldbJC6aVEQM9fdxf/LLBpdPEQOvyeDQZ4wrod4zL8WVlRtFi+90AbMNvVPio5TdYzqdi9TLg2RFgvzysvfUwZUwU+mTareqT+xLSCE+oH4tEpe6lCYLvmQI0e1awvuHbz7njsmLwiNUI2Kyh+wQZdjqhOftiMTTmgq748WvfGWje7Jy446RSRX4ssuTk+XvG5xGTyY0sou0XGIT74qh+/2Fn85EyBghKhsHDws55wUlU1MJBnlF3YWf0YVqgAkwd+cKr5mDgc1pNmhB6BL2mV32t2IKn3V5Gb3fjT6GL+Yn0rRCyiTDcHdhX65Vdd/XNBtkAnVLPJNw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=arctic.de; dmarc=pass action=none header.from=arctic.de; dkim=pass header.d=arctic.de; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Arctic.de; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=0zWtBUSm5e7I9A/LWX37+NKXs9HHxRxBa9yqiA8yLOc=; b=f2nj5eYXKAezkCXnSAI9UoluhFWeAcPDj9t04f6smixGl7Od4omM2AJsLzVajwZhDw/p34EkYmb/pnDN3nzysKZQYj54xmiGCmVNTg8n5Wu8E11Ltm0Qza/Djuvj0/qDc7lHg5WwujNCWnGLC1x0//4qG3RRRoPAtKQcCwtoVIl5VsEoy0agQ4HGZPZPQJzRWXf2+PVpE0Vg4H1LF+YztCDKgulWL+rI7FLXjiHcr9r93h8SoPmFqRgc6uX6UaCOf3og4SWTRELj1YaVxVKCiPuTFgNhto7hDXJrSWjeODMDTjOvVdpJDitu4gbBzy+JcAgRBpaqbsgXCGYUWagJBg== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arctic.de; Received: from FRVP281MB5895.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:1c3::20) by BE1P281MB3156.DEUP281.PROD.OUTLOOK.COM (2603:10a6:b10:68::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9723.23; Fri, 20 Mar 2026 08:10:07 +0000 Received: from FRVP281MB5895.DEUP281.PROD.OUTLOOK.COM ([fe80::c6a2:6e8f:ea:cc0d]) by FRVP281MB5895.DEUP281.PROD.OUTLOOK.COM ([fe80::c6a2:6e8f:ea:cc0d%5]) with mapi id 15.20.9723.022; Fri, 20 Mar 2026 08:10:07 +0000 From: Aureo Serrano de Souza To: linux-hwmon@vger.kernel.org Cc: linux@roeck-us.net, linux@weissschuh.net, corbet@lwn.net, skhan@linuxfoundation.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Aureo Serrano de Souza Subject: [PATCH v4] hwmon: add driver for ARCTIC Fan Controller Date: Fri, 20 Mar 2026 16:08:39 +0800 Message-ID: <20260320080840.333968-1-aureo.serrano@arctic.de> X-Mailer: git-send-email 2.43.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: TYCP301CA0076.JPNP301.PROD.OUTLOOK.COM (2603:1096:405:7b::10) To FRVP281MB5895.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:1c3::20) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: FRVP281MB5895:EE_|BE1P281MB3156:EE_ X-MS-Office365-Filtering-Correlation-Id: 23de776f-9e8c-41a9-7409-08de86581975 X-MS-Exchange-AtpMessageProperties: SA X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|52116014|376014|1800799024|366016|55112099003|38350700014|18002099003|56012099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:FRVP281MB5895.DEUP281.PROD.OUTLOOK.COM;PTR:;CAT:NONE;SFS:(13230040)(52116014)(376014)(1800799024)(366016)(55112099003)(38350700014)(18002099003)(56012099003);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?QXFsWHFtTkh3QTF2VkVZTGNoL0ovSWlhRVNFQjM0Z1FaVGVOVzFXT2V6TUxs?= =?utf-8?B?TjJiMXRhTHhLSE53MGRQck5PZ1pNWkxJY1lhWmJNYWNvajFtRmxtNzBlaHh2?= =?utf-8?B?UFNJcmRGa0ZtRE83eGp0eUVKNUhOc0d2cWx1b2hEb1FyRXJWaHFLdUhCTnBo?= =?utf-8?B?MHlVMEtXZ3FQY1JSOVJHS1VScWZHVmRnSFZBekRBU2c1cFVIQVpoblA2cTMy?= =?utf-8?B?QjRjQ3RXU0pxYnhWUE9oaHYwQWVOVHNuclZyNEhSdzFzY3ZRbjhIRG0rYUcy?= =?utf-8?B?eHRNYytBK1g4TXBzT0JFMmVQalpQNFoyR0IxazMzRXFqRXJhVmsyOUxwQVVF?= =?utf-8?B?Z2ZHUlNTckJoYnh1Yk1weFVpKzd5TWdVZ1ZJZ0hNdDdrbFRJNkY4K1dlVkdD?= =?utf-8?B?K09ZdldGZlJxdW1XRzFVVXB6WjRvdVBHbWhkMlduMFM0cjFaNlVjanpWUEpH?= =?utf-8?B?cHFydkZYTDBEQ0d1UDBiejVMWFRWeVFkb0piYzNTbmh4aXNtUXJxV2c1Z1dW?= =?utf-8?B?M3ZmcTdxRURGODhIWmZlcmQwZUZyT291a21PTmFJelBKWEVrRi9XbTN4OEJL?= =?utf-8?B?UmtDMWRLR25GNGJBVjFtWFdsN0VpdWdLZnFTM0hQZXJ4TzNkcXF1M0h1Skxa?= =?utf-8?B?Vjh0NTVnQi9xNFpENVdFSlNweEErKzhlWVlrQjVlWTRFNmk1SkRUaElCbzQv?= =?utf-8?B?cFhkWHowdVErTTNlekFsOUtlUDlCZ0d0a08zR2N2MFJsK1pCaE80d0NhbjRt?= =?utf-8?B?cUp1dEluSzBSWEN1Z2dsV1JyNzVabi9vNklXM2d1UHFkT2dFdVJpdTdCUHgy?= =?utf-8?B?c1Y4NEpEbUtuVG5ycHBwd1JHQ2JTK2wyM084a1lXZ25UQVVGVEhzRGpyYlJi?= =?utf-8?B?Q29LSXBZZ3FoSytydVltMzBzRG5DOWhCdzV4VlJEUVlETXJVUmwrOWdHVGRK?= =?utf-8?B?SjFIUFBuZWxNV3gyL1dCYzU3alZaeDBiVGs1UTMwV0FpQkFMTndZVllqalBJ?= =?utf-8?B?MEZ4UUhaQzQ4SlFjbEVPeUx0YzNHeUxtZ2o1NndaMVlEbEROLzB6VVd0MmhM?= =?utf-8?B?eVRodVZ0c1V4bERHL0w4cUkxTmVpYkpYS0lQT2NrSHdIdlRzNGJ5U0tPMlRm?= =?utf-8?B?Y1Y3c1FxM3NMbFUvbllaVnc3akYraHVtSytZTmxBQUd2OW5UYlM1d3RzaThr?= =?utf-8?B?UWpIWGJGUTNFeDlZY012UEt2eEhxWm5OUmZyV1FDcm9ZTEZhNjFGeFVIZFdJ?= =?utf-8?B?WVB1WG5OcW91T1RHQlpkbW9jRU41MythZStxQWxZNmtmby94U3YxazFkVVl1?= =?utf-8?B?SWZDRVhvV0JOdHMrbWFwNlRmK0RQMG8zdGRZZzRuVFp4MTJ2dkNSY1BvTU03?= =?utf-8?B?Wk53TUxQbWhrUHlIZHZFTmZhcWRBLzAvbkdScSs5R05oK0tucEQzek5Rdndt?= =?utf-8?B?M2lSM1ZuWkdlN2x1Z0ZaRFFJQloyd0Z5cDFRZjdCNzdBenR3N3BicWRXQ25j?= =?utf-8?B?V2I5SW9mekJUV2RSSmUrWXFPaUR0ODh6alR5VmxpR3huTUFvcmtEa0d5VkJO?= =?utf-8?B?eU9JMlVjNzA2MjdoZ3dSZm9aOEl4dXIzSWRwSkp4OCtMS1V2eEM2ZUNvQnVR?= =?utf-8?B?MmpSUTBtNldNakYwb21NUE9zcUlhVEFEYVByeDQ0Mk9NSXhPYTQva25DWUFl?= =?utf-8?B?bWRhNW11M3Ntak5oQ0NBd24vNjk5VFdRbXJqdnRvY1BweUhzSEdTOEZweHcv?= =?utf-8?B?b3pieTVPZjgwbGJrYUlDM2FrWlZablZIQ3krNUowS3RuNFFRdjBLTEdZaUM5?= =?utf-8?B?cFc2ZGxYbEFYUWswM1V0Q25yOExrYU9JMS8xajdkZWp6SjgySE1xampsRi9x?= =?utf-8?B?ZnFGc2RCTnFVUWN5azhrQ2dEaTg1bUNlWkZxSHQ5S0x5cVMxNUpWdjBUeDhn?= =?utf-8?B?WUhzVHMwMFllYldFc3MvcldLYTJzOVluVHVaTXdTOE1IeWRONHAreE5Ub0pP?= =?utf-8?B?dzF5enptYUJVeFBuMDllM0tjMk1LbVJDREduRnJlNUpBbmNSLytnaDU4N3My?= =?utf-8?B?b3VKbG1qUU0vWGpqMWtnQjNveFAxNkJJb240bnNwVnV3VENRTDNlR0tNYU5p?= =?utf-8?B?QkJuQ2NlQXRlTzhzMXE4Tk9kb0RqRUx5U3JMNGhSdFROWGZQbXlwaW80NlI0?= =?utf-8?B?RFFlOWppREJkOXgvUFQwRDVDdXp0R084ajhGV2hRUCtwbXhSbWVSVEdvb1Fh?= =?utf-8?B?bU1DMlZEUU1XV09DZGtPQ0o4Z21BTjgrUFVIMlhEQVpad2tFMHNKRkhJY2VO?= =?utf-8?B?Vi9YWXZqbFNFbVdac2Y1cnY3TC9IVURzOEpxeFd0bU9Ba3pDV0Judz09?= X-OriginatorOrg: Arctic.de X-MS-Exchange-CrossTenant-Network-Message-Id: 23de776f-9e8c-41a9-7409-08de86581975 X-MS-Exchange-CrossTenant-AuthSource: FRVP281MB5895.DEUP281.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Mar 2026 08:10:07.7615 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 51cc2c5f-af21-4667-81ec-d88d36e264bb X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: F6F4MuqriPhzpPn9FMiENSKlwou2BPfBDInQeNiFYnADifKaK0/vqqavG+O7TNWyFV4UuirHUjhzPL+/giVUGQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BE1P281MB3156 Add hwmon driver for the ARCTIC Fan Controller, a USB HID device (VID 0x3904, PID 0xF001) with 10 fan channels. Exposes fan speed in RPM (read-only) and PWM duty cycle (0-255, read/write) via sysfs. The device pushes IN reports at ~1 Hz containing RPM readings. PWM is set via OUT reports; the device applies the new duty cycle and sends back a 2-byte ACK (Report ID 0x02). The driver waits up to 1 s for the ACK using a completion. Measured device latency: max ~563 ms over 500 iterations. PWM control is manual-only: the device never changes duty cycle autonomously. raw_event() may run in hardirq context, so fan_rpm[] is protected by a spinlock with irq-save. pwm_duty[] and the report buffer are serialized by the hwmon core, which holds its lock for the duration of the read/write callbacks. Signed-off-by: Aureo Serrano de Souza --- Thanks to Guenter Roeck and Thomas Wei=C3=9Fschuh for the reviews. Changes since v3: - buf[]: upgrade from __aligned(8) to ____cacheline_aligned so the DMA buffer occupies its own cache line, preventing false sharing with adjacent fan_rpm[]/pwm_duty[] fields on non-coherent architectures - arctic_fan_write(): add write_pending flag (protected by in_report_lock) so raw_event() delivers ACKs only while a write is in flight; prevents a late ACK from a signal-interrupted write from satisfying a subsequent write's completion wait - arctic_fan_write(): commit pwm_duty[channel] only after the device ACKs the command; a failed or timed-out write no longer leaves a stale value in the cached duty state - arctic_fan_probe(): start IO (hid_device_io_start) before registering with hwmon; previously a sysfs write arriving between hwmon registration and io_start could send an OUT report whose ACK would be discarded by the HID core, causing a spurious timeout - Documentation/hwmon/arctic_fan_controller.rst: document that cached PWM values start at 0 (hardware state unknown at probe) and that each OUT report carries all 10 channel values Changes since v2: - buf[]: add __aligned(8) for DMA safety - ARCTIC_ACK_TIMEOUT_MS: restore 1000 ms; note observed max ~563 ms - arctic_fan_parse_report(): replace hwmon_lock/hwmon_unlock with spin_lock_irqsave; hwmon_lock() may sleep and is unsafe when raw_event() runs in hardirq/softirq context - arctic_fan_raw_event(): use spin_lock_irqsave for ACK path - arctic_fan_write(): use spin_lock_irqsave for completion reinit - arctic_fan_write(): clamp val to [0, 255] before u8 cast - hardware teardown: register arctic_fan_hw_stop() via devm_add_action_or_reset() before hwmon; devm LIFO order ensures hwmon unregisters before hid_hw_close/stop; remove() is a no-op - remove priv->hwmon_dev (no longer needed) Changes since v1: - Use hid_dbg() instead of module_param debug flag - Move hid_device_id table adjacent to hid_driver struct - Use get_unaligned_le16() for RPM parsing - Remove impossible bounds/NULL checks; remove retry loop - Add hid_is_usb() guard - Do not update pwm_duty from IN reports (device is manual-only) - Add completion/ACK mechanism for OUT report acknowledgement - Add Documentation/hwmon/arctic_fan_controller.rst and MAINTAINERS diff --git a/Documentation/hwmon/arctic_fan_controller.rst b/Documentation/= hwmon/arctic_fan_controller.rst new file mode 100644 index 0000000000..834f09c813 --- /dev/null +++ b/Documentation/hwmon/arctic_fan_controller.rst @@ -0,0 +1,49 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +Kernel driver arctic_fan_controller +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D + +Supported devices: + +* ARCTIC Fan Controller (USB HID, VID 0x3904, PID 0xF001) + +Author: Aureo Serrano de Souza + +Description +----------- + +This driver provides hwmon support for the ARCTIC Fan Controller, a USB +Custom HID device with 10 fan channels. The device sends IN reports about +once per second containing current RPM values (bytes 11-30, 10 x uint16 LE= ). +Fan speed control is manual-only: the device does not change PWM +autonomously; it only applies a new duty cycle when it receives an OUT +report from the host. + +After the device applies an OUT report, it sends back a 2-byte ACK IN +report (Report ID 0x02, byte 1 =3D 0x00 on success) confirming the command +was applied. + +Usage notes +----------- + +Since it is a USB device, hotplug is supported. The device is autodetected. + +The device does not support GET_REPORT, so the driver cannot read back the +current hardware PWM state at probe time. The cached PWM values (readable +via pwm[1-10]) start at 0 and reflect only values that have been +successfully written. Because each OUT report carries all 10 channel value= s, +writing a single channel also sends the cached values for all other channe= ls. +Users should set all channels to the desired values before relying on the +cached state. + +Sysfs entries +------------- + +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D +fan[1-10]_input Fan speed in RPM (read-only). Updated from IN reports at = ~1 Hz. +pwm[1-10] PWM duty cycle (0-255). Write: sends an OUT report settin= g the + duty cycle (scaled from 0-255 to 0-100% for the device); + the cached value is updated only after the device ACKs the + command. Read: returns the last successfully written valu= e; + initialized to 0 at driver load (hardware state unknown). +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index b2ca8513cf..c34713040e 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -42,6 +42,7 @@ Hardware Monitoring Kernel Drivers aht10 amc6821 aquacomputer_d5next + arctic_fan_controller asb100 asc7621 aspeed-g6-pwm-tach diff --git a/MAINTAINERS b/MAINTAINERS index 96ea84948d..ec3112bd41 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2053,6 +2053,13 @@ S: Maintained F: drivers/net/arcnet/ F: include/uapi/linux/if_arcnet.h +ARCTIC FAN CONTROLLER DRIVER +M: Aureo Serrano de Souza +L: linux-hwmon@vger.kernel.org +S: Maintained +F: Documentation/hwmon/arctic_fan_controller.rst +F: drivers/hwmon/arctic_fan_controller.c + ARM AND ARM64 SoC SUB-ARCHITECTURES (COMMON PARTS) M: Arnd Bergmann M: Krzysztof Kozlowski diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 328867242c..6c90a8dd40 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -388,6 +388,18 @@ config SENSORS_APPLESMC Say Y here if you have an applicable laptop and want to experience the awesome power of applesmc. +config SENSORS_ARCTIC_FAN_CONTROLLER + tristate "ARCTIC Fan Controller" + depends on USB_HID + help + If you say yes here you get support for the ARCTIC Fan Controller, + a USB HID device (VID 0x3904, PID 0xF001) with 10 fan channels. + The driver exposes fan speed (RPM) and PWM control via the hwmon + sysfs interface. + + This driver can also be built as a module. If so, the module + will be called arctic_fan_controller. + config SENSORS_ARM_SCMI tristate "ARM SCMI Sensors" depends on ARM_SCMI_PROTOCOL diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 5833c807c6..ef831c3375 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -49,6 +49,7 @@ obj-$(CONFIG_SENSORS_ADT7475) +=3D adt7475.o obj-$(CONFIG_SENSORS_AHT10) +=3D aht10.o obj-$(CONFIG_SENSORS_APPLESMC) +=3D applesmc.o obj-$(CONFIG_SENSORS_AQUACOMPUTER_D5NEXT) +=3D aquacomputer_d5next.o +obj-$(CONFIG_SENSORS_ARCTIC_FAN_CONTROLLER) +=3D arctic_fan_controller.o obj-$(CONFIG_SENSORS_ARM_SCMI) +=3D scmi-hwmon.o obj-$(CONFIG_SENSORS_ARM_SCPI) +=3D scpi-hwmon.o obj-$(CONFIG_SENSORS_AS370) +=3D as370-hwmon.o diff --git a/drivers/hwmon/arctic_fan_controller.c b/drivers/hwmon/arctic_f= an_controller.c new file mode 100644 index 0000000000..7b991735ed --- /dev/null +++ b/drivers/hwmon/arctic_fan_controller.c @@ -0,0 +1,328 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Linux hwmon driver for ARCTIC Fan Controller + * + * USB Custom HID device with 10 fan channels. + * Exposes fan RPM (input) and PWM (0-255) via hwmon. Device pushes IN rep= orts + * at ~1 Hz; no GET_REPORT. OUT reports set PWM duty (bytes 1-10, 0-100%). + * PWM is manual-only: the device does not change duty autonomously, only + * when it receives an OUT report from the host. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define ARCTIC_VID 0x3904 +#define ARCTIC_PID 0xF001 +#define ARCTIC_NUM_FANS 10 +#define ARCTIC_OUTPUT_REPORT_ID 0x01 +#define ARCTIC_REPORT_LEN 32 +#define ARCTIC_RPM_OFFSET 11 /* bytes 11-30: 10 x uint16 LE */ +/* ACK report: device sends Report ID 0x02, 2 bytes (ID + status) after ap= plying OUT report */ +#define ARCTIC_ACK_REPORT_ID 0x02 +#define ARCTIC_ACK_REPORT_LEN 2 +/* + * Time to wait for ACK report after send. + * Measured over 500 iterations: max ~563 ms. Keep 1 s as margin. + */ +#define ARCTIC_ACK_TIMEOUT_MS 1000 + +struct arctic_fan_data { + struct hid_device *hdev; + spinlock_t in_report_lock; /* protects fan_rpm[], ack_status, write_pendi= ng */ + struct completion in_report_received; /* ACK (ID 0x02) received in raw_ev= ent */ + int ack_status; /* 0 =3D OK, negative errno on device error */ + bool write_pending; /* true while an OUT report ACK is in flight */ + u32 fan_rpm[ARCTIC_NUM_FANS]; + u8 pwm_duty[ARCTIC_NUM_FANS]; /* 0-255 matching sysfs range; converted to= 0-100 on send */ + /* + * OUT report buffer. Cache-line aligned so it occupies its own cache + * line, preventing DMA cache-coherency issues with adjacent fields + * (fan_rpm[], pwm_duty[]) on non-coherent architectures. + * Embedded in the devm_kzalloc'd struct so it is heap-allocated and + * passes usb_hcd_map_urb_for_dma(). Serialized by the hwmon core. + */ + u8 buf[ARCTIC_REPORT_LEN] ____cacheline_aligned; +}; + +/* + * Parse RPM values from the periodic status report (10 x uint16 LE at rpm= _off). + * pwm_duty is not updated from the report: the device is manual-only, so = the + * host cache is the authoritative source for PWM. + * Called from raw_event which may run in IRQ context; must not sleep. + */ +static void arctic_fan_parse_report(struct arctic_fan_data *priv, u8 *buf, + int len, int rpm_off) +{ + unsigned long flags; + int i; + + if (len < rpm_off + 20) + return; + + spin_lock_irqsave(&priv->in_report_lock, flags); + for (i =3D 0; i < ARCTIC_NUM_FANS; i++) + priv->fan_rpm[i] =3D get_unaligned_le16(&buf[rpm_off + i * 2]); + spin_unlock_irqrestore(&priv->in_report_lock, flags); +} + +/* + * raw_event: IN reports. + * + * Status report: Report ID 0x01, 32 bytes: + * byte 0 =3D report ID, bytes 1-10 =3D PWM 0-100%, bytes 11-30 =3D 10 x= RPM uint16 LE. + * Device pushes these at ~1 Hz; no GET_REPORT. + * + * ACK report: Report ID 0x02, 2 bytes: + * byte 0 =3D 0x02, byte 1 =3D status (0x00 =3D OK, 0x01 =3D ERROR). + * Sent once after accepting and applying an OUT report (ID 0x01). + */ +static int arctic_fan_raw_event(struct hid_device *hdev, + struct hid_report *report, u8 *data, int size) +{ + struct arctic_fan_data *priv =3D hid_get_drvdata(hdev); + unsigned long flags; + + hid_dbg(hdev, "arctic_fan: raw_event id=3D%u size=3D%d\n", report->id, si= ze); + + if (report->id =3D=3D ARCTIC_ACK_REPORT_ID && size =3D=3D ARCTIC_ACK_REPO= RT_LEN) { + spin_lock_irqsave(&priv->in_report_lock, flags); + /* + * Only deliver if a write is in flight. This prevents a + * late-arriving ACK from a signal-interrupted write from + * erroneously satisfying a subsequent write's completion wait. + */ + if (priv->write_pending) { + priv->ack_status =3D data[1] =3D=3D 0x00 ? 0 : -EIO; + complete(&priv->in_report_received); + } + spin_unlock_irqrestore(&priv->in_report_lock, flags); + return 0; + } + + if (report->id !=3D ARCTIC_OUTPUT_REPORT_ID || size !=3D ARCTIC_REPORT_LE= N) { + hid_dbg(hdev, "arctic_fan: raw_event id=3D%u size=3D%d ignored\n", + report->id, size); + return 0; + } + + arctic_fan_parse_report(priv, data, size, ARCTIC_RPM_OFFSET); + return 0; +} + +static umode_t arctic_fan_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + if (type =3D=3D hwmon_fan && attr =3D=3D hwmon_fan_input) + return 0444; + if (type =3D=3D hwmon_pwm && attr =3D=3D hwmon_pwm_input) + return 0644; + return 0; +} + +static int arctic_fan_read(struct device *dev, enum hwmon_sensor_types typ= e, + u32 attr, int channel, long *val) +{ + struct arctic_fan_data *priv =3D dev_get_drvdata(dev); + unsigned long flags; + + if (type =3D=3D hwmon_fan && attr =3D=3D hwmon_fan_input) { + spin_lock_irqsave(&priv->in_report_lock, flags); + *val =3D priv->fan_rpm[channel]; + spin_unlock_irqrestore(&priv->in_report_lock, flags); + return 0; + } + if (type =3D=3D hwmon_pwm && attr =3D=3D hwmon_pwm_input) { + /* pwm_duty is modified only in write(), which the hwmon core serializes= */ + *val =3D priv->pwm_duty[channel]; + return 0; + } + return -EINVAL; +} + +static int arctic_fan_write(struct device *dev, enum hwmon_sensor_types ty= pe, + u32 attr, int channel, long val) +{ + struct arctic_fan_data *priv =3D dev_get_drvdata(dev); + u8 new_duty =3D (u8)clamp_val(val, 0, 255); + unsigned long flags; + long t; + int i, ret; + + /* + * The hwmon core holds its lock for the duration of this callback, + * serializing concurrent writes. priv->buf is heap-allocated (embedded + * in the devm_kzalloc'd struct), satisfying usb_hcd_map_urb_for_dma(). + * + * Use new_duty for the target channel and the cached value for all + * others. pwm_duty[channel] is committed only after a confirmed ACK so + * a failed or timed-out write does not corrupt the cached duty state. + */ + priv->buf[0] =3D ARCTIC_OUTPUT_REPORT_ID; + for (i =3D 0; i < ARCTIC_NUM_FANS; i++) + priv->buf[1 + i] =3D DIV_ROUND_CLOSEST( + (unsigned int)(i =3D=3D channel ? new_duty : priv->pwm_duty[i]) * 100, = 255); + + /* + * Set write_pending before sending the report and clear it in every + * exit path. raw_event() calls complete() only when write_pending is + * true, so a stale ACK from a signal-interrupted write cannot + * satisfy the next write's completion wait. + * Serialized by the hwmon core: only one arctic_fan_write() at a time. + * Use irqsave to match the IRQ context in which raw_event may run. + */ + spin_lock_irqsave(&priv->in_report_lock, flags); + priv->ack_status =3D -ETIMEDOUT; + priv->write_pending =3D true; + reinit_completion(&priv->in_report_received); + spin_unlock_irqrestore(&priv->in_report_lock, flags); + + ret =3D hid_hw_output_report(priv->hdev, priv->buf, ARCTIC_REPORT_LEN); + if (ret < 0) { + spin_lock_irqsave(&priv->in_report_lock, flags); + priv->write_pending =3D false; + spin_unlock_irqrestore(&priv->in_report_lock, flags); + return ret; + } + + t =3D wait_for_completion_interruptible_timeout(&priv->in_report_received, + msecs_to_jiffies(ARCTIC_ACK_TIMEOUT_MS)); + spin_lock_irqsave(&priv->in_report_lock, flags); + priv->write_pending =3D false; + spin_unlock_irqrestore(&priv->in_report_lock, flags); + + if (t < 0) + return t; /* interrupted by signal */ + if (!t) + return -ETIMEDOUT; + + /* Commit the new duty only after hardware has acknowledged it */ + priv->pwm_duty[channel] =3D new_duty; + return priv->ack_status; /* 0=3DOK, -EIO=3Ddevice error */ +} + +static const struct hwmon_ops arctic_fan_ops =3D { + .is_visible =3D arctic_fan_is_visible, + .read =3D arctic_fan_read, + .write =3D arctic_fan_write, +}; + +static const struct hwmon_channel_info *arctic_fan_info[] =3D { + HWMON_CHANNEL_INFO(fan, + HWMON_F_INPUT, HWMON_F_INPUT, HWMON_F_INPUT, + HWMON_F_INPUT, HWMON_F_INPUT, HWMON_F_INPUT, + HWMON_F_INPUT, HWMON_F_INPUT, HWMON_F_INPUT, + HWMON_F_INPUT), + HWMON_CHANNEL_INFO(pwm, + HWMON_PWM_INPUT, HWMON_PWM_INPUT, HWMON_PWM_INPUT, + HWMON_PWM_INPUT, HWMON_PWM_INPUT, HWMON_PWM_INPUT, + HWMON_PWM_INPUT, HWMON_PWM_INPUT, HWMON_PWM_INPUT, + HWMON_PWM_INPUT), + NULL +}; + +static const struct hwmon_chip_info arctic_fan_chip_info =3D { + .ops =3D &arctic_fan_ops, + .info =3D arctic_fan_info, +}; + +static void arctic_fan_hw_stop(void *data) +{ + struct hid_device *hdev =3D data; + + hid_hw_close(hdev); + hid_hw_stop(hdev); +} + +static int arctic_fan_probe(struct hid_device *hdev, + const struct hid_device_id *id) +{ + struct arctic_fan_data *priv; + struct device *hwmon_dev; + int ret; + + if (!hid_is_usb(hdev)) + return -ENODEV; + + ret =3D hid_parse(hdev); + if (ret) + return ret; + + priv =3D devm_kzalloc(&hdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->hdev =3D hdev; + spin_lock_init(&priv->in_report_lock); + init_completion(&priv->in_report_received); + hid_set_drvdata(hdev, priv); + + ret =3D hid_hw_start(hdev, HID_CONNECT_DRIVER); + if (ret) + return ret; + + ret =3D hid_hw_open(hdev); + if (ret) { + hid_hw_stop(hdev); + return ret; + } + + /* + * Register hardware teardown before hwmon so that devm cleanup runs in + * LIFO order: hwmon unregistered first, then hid_hw_close/stop. This + * ensures no userspace sysfs write can reach an already stopped device. + */ + ret =3D devm_add_action_or_reset(&hdev->dev, arctic_fan_hw_stop, hdev); + if (ret) + return ret; + + /* + * Start IO before registering with hwmon. If IO were started after + * hwmon registration, a sysfs write arriving in that narrow window + * would send an OUT report but the ACK could not be delivered (the HID + * core discards events until io_started), causing a spurious timeout. + */ + hid_device_io_start(hdev); + + hwmon_dev =3D devm_hwmon_device_register_with_info(&hdev->dev, "arctic_fa= n", + priv, &arctic_fan_chip_info, + NULL); + if (IS_ERR(hwmon_dev)) + return PTR_ERR(hwmon_dev); + + return 0; +} + +static void arctic_fan_remove(struct hid_device *hdev) +{ + /* devm cleanup (LIFO) handles hid_hw_close/stop after hwmon unregistrati= on */ +} + +static const struct hid_device_id arctic_fan_id_table[] =3D { + { HID_USB_DEVICE(ARCTIC_VID, ARCTIC_PID) }, + { } +}; +MODULE_DEVICE_TABLE(hid, arctic_fan_id_table); + +static struct hid_driver arctic_fan_driver =3D { + .name =3D "arctic_fan", + .id_table =3D arctic_fan_id_table, + .probe =3D arctic_fan_probe, + .remove =3D arctic_fan_remove, + .raw_event =3D arctic_fan_raw_event, +}; + +module_hid_driver(arctic_fan_driver); + +MODULE_AUTHOR("Aureo Serrano de Souza "); +MODULE_DESCRIPTION("HID hwmon driver for ARCTIC Fan Controller"); +MODULE_LICENSE("GPL");