From patchwork Fri Sep 9 13:37:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ibrahim Tilki X-Patchwork-Id: 604354 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C35CEECAAD3 for ; Fri, 9 Sep 2022 13:38:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229598AbiIINiS (ORCPT ); Fri, 9 Sep 2022 09:38:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231366AbiIINiR (ORCPT ); Fri, 9 Sep 2022 09:38:17 -0400 Received: from mx0a-00128a01.pphosted.com (mx0a-00128a01.pphosted.com [148.163.135.77]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2950C138E52; Fri, 9 Sep 2022 06:38:14 -0700 (PDT) Received: from pps.filterd (m0167089.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 289CkC8I031368; Fri, 9 Sep 2022 09:37:56 -0400 Received: from nwd2mta3.analog.com ([137.71.173.56]) by mx0a-00128a01.pphosted.com (PPS) with ESMTPS id 3jf8yc3pqd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 09 Sep 2022 09:37:56 -0400 Received: from ASHBMBX9.ad.analog.com (ASHBMBX9.ad.analog.com [10.64.17.10]) by nwd2mta3.analog.com (8.14.7/8.14.7) with ESMTP id 289DbtRD042474 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 9 Sep 2022 09:37:55 -0400 Received: from ASHBMBX9.ad.analog.com (10.64.17.10) by ASHBMBX9.ad.analog.com (10.64.17.10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.14; Fri, 9 Sep 2022 09:37:54 -0400 Received: from zeus.spd.analog.com (10.66.68.11) by ashbmbx9.ad.analog.com (10.64.17.10) with Microsoft SMTP Server id 15.2.986.14 via Frontend Transport; Fri, 9 Sep 2022 09:37:54 -0400 Received: from ibrahim-vm.ad.analog.com ([10.158.19.28]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 289DbUul018872; Fri, 9 Sep 2022 09:37:44 -0400 From: Ibrahim Tilki To: , CC: Ibrahim Tilki , , , , , Subject: [PATCH v8 2/4] docs: hwmon: add max31760 documentation Date: Fri, 9 Sep 2022 16:37:16 +0300 Message-ID: <20220909133718.388213-3-Ibrahim.Tilki@analog.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220909133718.388213-1-Ibrahim.Tilki@analog.com> References: <20220909133718.388213-1-Ibrahim.Tilki@analog.com> MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-GUID: RdtRClOnrMq_rUGmOFIgjPugp47v-L_E X-Proofpoint-ORIG-GUID: RdtRClOnrMq_rUGmOFIgjPugp47v-L_E X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-09-09_08,2022-09-09_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 adultscore=0 impostorscore=0 priorityscore=1501 malwarescore=0 mlxlogscore=999 lowpriorityscore=0 mlxscore=0 bulkscore=0 spamscore=0 suspectscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2207270000 definitions=main-2209090047 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Adding documentation for max31760 fan speed controller Signed-off-by: Ibrahim Tilki --- Documentation/hwmon/index.rst | 1 + Documentation/hwmon/max31760.rst | 77 ++++++++++++++++++++++++++++++++ 2 files changed, 78 insertions(+) create mode 100644 Documentation/hwmon/max31760.rst diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index f7113b0f8..dba260013 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -133,6 +133,7 @@ Hardware Monitoring Kernel Drivers max20751 max31722 max31730 + max31760 max31785 max31790 max34440 diff --git a/Documentation/hwmon/max31760.rst b/Documentation/hwmon/max31760.rst new file mode 100644 index 000000000..b1b55fb84 --- /dev/null +++ b/Documentation/hwmon/max31760.rst @@ -0,0 +1,77 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +Kernel driver max31760 +====================== + +Supported chips: + * Analog Devices MAX31760 + + Prefix: 'max31760' + + Addresses scanned: none + + Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX31760.pdf + + +Author: Ibrahim Tilki + +Description +----------- + +The MAX31760 integrates temperature sensing along with precision PWM fan +control. It accurately measures its local die temperature and the remote +temperature of a discrete diode-connected transistor, such as a 2N3906, +or a thermal diode commonly found on CPUs, graphics processor units (GPUs), +and other ASICs. Multiple temperature thresholds, such as local +high/overtemperature (OT) and remote high/overtemperature, can be set by an +I2C-compatible interface. Fan speed is controlled based on the temperature +reading as an index to a 48-byte lookup table (LUT) containing +user-programmed PWM values. The flexible LUT-based architecture enables +the user to program a smooth nonlinear fan speed vs. temperature transfer +function to minimize acoustic fan noise. Two tachometer inputs allow +measuring the speeds of two fans independently. When the local or remote +OT threshold is exceeded, the SHDN pin is asserted low and can be used to +shut down the system. A dedicated ALERT pin reports that either a local or +remote high-temperature threshold has been exceeded. + +Temperature measurement range: from -55°C to 125°C + +Temperature Resolution: 11 Bits, ±0.125°C + +Please refer how to instantiate this driver: Documentation/i2c/instantiating-devices.rst + +Lookup table for auto fan control +--------------------------------- + +========= ================================= +LUT Index Name +========= ================================= +1 PWM value for T < +18°C +2 PWM value for +18°C ≤ T < +20°C +3 PWM value for +20°C ≤ T < +22°C +... ... +47 PWM value for +108°C ≤ T < +110°C +48 PWM value for T ≥ +110°C +========= ================================= + +Sysfs entries +------------- + +=============================== ================================================================================= +fan[1-2]_input Fan speed (in RPM) +fan[1-2]_enable Enable fan readings and fan fault alarms +fan[1-2]_fault Fan fault status +temp[1-2]_label "Remote" and "Local" temperature channel labels +temp[1-2]_input Temperature sensor readings (in millidegrees Celsius) +temp1_fault Remote temperature sensor fault status +temp[1-2]_max Temperature max value. Asserts "ALERT" pin when exceeded +temp[1-2]_max_alarm Temperature max alarm status +temp[1-2]_crit Temperature critical value. Asserts "SHDN" pin when exceeded +temp[1-2]_crit_alarm Temperature critical alarm status +pwm1 PWM value for direct fan control +pwm1_enable 1: direct fan control, 2: temperature based auto fan control +pwm1_freq PWM frequency in hertz +pwm1_auto_channels_temp Temperature source for auto fan control. 1: temp1, 2: temp2, 3: max(temp1, temp2) +pwm1_auto_point[1-48]_pwm PWM value for LUT point +pwm1_auto_point_temp_hyst Temperature hysteresis for auto fan control. Can be either 2000mC or 4000mC +=============================== =================================================================================