From patchwork Fri Nov 4 11:02:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rasmus Villemoes X-Patchwork-Id: 13031646 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 048BBC4332F for ; Fri, 4 Nov 2022 11:03:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231861AbiKDLDN (ORCPT ); Fri, 4 Nov 2022 07:03:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39594 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231893AbiKDLCb (ORCPT ); Fri, 4 Nov 2022 07:02:31 -0400 Received: from mail-ej1-x62e.google.com (mail-ej1-x62e.google.com [IPv6:2a00:1450:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8633B2CCB5 for ; Fri, 4 Nov 2022 04:02:30 -0700 (PDT) Received: by mail-ej1-x62e.google.com with SMTP id ud5so12346153ejc.4 for ; Fri, 04 Nov 2022 04:02:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rasmusvillemoes.dk; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=6qsrjmAB2bc2yZOLis4WUU4zk1hVdcgBYDjuUdZNYJA=; b=Q0ouS1ZTGKV2jT9hNgwTXGwSTy8uz5eBnuEvnM5BR9n4JtOT+WWokoUvZjpgbRK+OZ KNuVSQ+XZMbtxGIeMNz07+RulsNwkIj62SCEf/WgUVRTO/gBEDA66HGWOXC9Eycj4SA7 I9QLRE9SbZDZdxuo+AWlxnmJt3QcPBPWWk+Cs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=6qsrjmAB2bc2yZOLis4WUU4zk1hVdcgBYDjuUdZNYJA=; b=TAdE4uXkSPxULw70q/6szQxusQTIIyvMBf0jElYhXrM3plg3GZWHeHOltGjL9P31RU p6nce8Qeqrv96d+ej0FyUcGYijCvT/xo/V7A0TrKpLHRyjaurwgQc9eljwL0mcJjXC28 wYcHcrDQXH3JjVaZKX3Y1PNA2TTjwZkiXjb5HunCB/FMt29ahSh7v5/GXmH+1+KfO0Ql 2w2F4hzlQ0Ep7fVtbCNVEf38wHxKsn5zGq1F6Qk4eq5QUZ7ZhxjqGqSbCHiYsHmluAAE L7hT3yrkdhkhCNSj1SzeyGgaTDGAvMJzmQVucgPjaGqF3D9HVpgfhKFJVHe62OaNmKJo LopQ== X-Gm-Message-State: ACrzQf3Sm6vBxTFehLLFgd8myEiDGbmNrw5IiWSUNI9zoggz1oNXMar9 04A5E3xTGQ66e6ck9Wrdx6RnrA== X-Google-Smtp-Source: AMsMyM7rPtx7R3xBAq3mAhmYoFuzglY0OrjxSCxDNSArUyvCF4XzPOlpRmGiNBPGszAIp9JtZATw4A== X-Received: by 2002:a17:907:7244:b0:78d:cedc:7a9e with SMTP id ds4-20020a170907724400b0078dcedc7a9emr33822938ejc.600.1667559748911; Fri, 04 Nov 2022 04:02:28 -0700 (PDT) Received: from prevas-ravi.prevas.se ([81.216.59.226]) by smtp.gmail.com with ESMTPSA id n28-20020a5099dc000000b004619f024864sm1777833edb.81.2022.11.04.04.02.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Nov 2022 04:02:28 -0700 (PDT) From: Rasmus Villemoes To: Alessandro Zummo , Alexandre Belloni , Jean Delvare , Guenter Roeck Cc: Rasmus Villemoes , linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org Subject: [PATCH v4] rtc: isl12022: add support for temperature sensor Date: Fri, 4 Nov 2022 12:02:25 +0100 Message-Id: <20221104110225.2219761-1-linux@rasmusvillemoes.dk> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20221026133847.1193422-1-linux@rasmusvillemoes.dk> References: <20221026133847.1193422-1-linux@rasmusvillemoes.dk> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org The isl12022 has built-in temperature compensation effective over the range -40C to +85C. It exposes the average of the last two temperature measurements as a 10-bit value in half-Kelvins. Make this available via the hwmon framework. Reviewed-by: Guenter Roeck Signed-off-by: Rasmus Villemoes --- v4: add a real commit log, include Guenter's R-b. v3 at https://lore.kernel.org/lkml/20221026133847.1193422-1-linux@rasmusvillemoes.dk/ drivers/rtc/rtc-isl12022.c | 94 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) diff --git a/drivers/rtc/rtc-isl12022.c b/drivers/rtc/rtc-isl12022.c index ca677c4265e6..a3b0de3393f5 100644 --- a/drivers/rtc/rtc-isl12022.c +++ b/drivers/rtc/rtc-isl12022.c @@ -17,6 +17,7 @@ #include #include #include +#include /* ISL register offsets */ #define ISL12022_REG_SC 0x00 @@ -30,6 +31,9 @@ #define ISL12022_REG_SR 0x07 #define ISL12022_REG_INT 0x08 +#define ISL12022_REG_BETA 0x0d +#define ISL12022_REG_TEMP_L 0x28 + /* ISL register bits */ #define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */ @@ -38,6 +42,7 @@ #define ISL12022_INT_WRTC (1 << 6) +#define ISL12022_BETA_TSE (1 << 7) static struct i2c_driver isl12022_driver; @@ -46,6 +51,93 @@ struct isl12022 { struct regmap *regmap; }; +static umode_t isl12022_hwmon_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + if (type == hwmon_temp && attr == hwmon_temp_input) + return 0444; + + return 0; +} + +/* + * A user-initiated temperature conversion is not started by this function, + * so the temperature is updated once every ~60 seconds. + */ +static int isl12022_hwmon_read_temp(struct device *dev, long *mC) +{ + struct isl12022 *isl12022 = dev_get_drvdata(dev); + struct regmap *regmap = isl12022->regmap; + u8 temp_buf[2]; + int temp, ret; + + ret = regmap_bulk_read(regmap, ISL12022_REG_TEMP_L, + temp_buf, sizeof(temp_buf)); + if (ret) + return ret; + /* + * Temperature is represented as a 10-bit number, unit half-Kelvins. + */ + temp = (temp_buf[1] << 8) | temp_buf[0]; + temp *= 500; + temp -= 273000; + + *mC = temp; + + return 0; +} + +static int isl12022_hwmon_read(struct device *dev, + enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + if (type == hwmon_temp && attr == hwmon_temp_input) + return isl12022_hwmon_read_temp(dev, val); + + return -EOPNOTSUPP; +} + +static const struct hwmon_channel_info *isl12022_hwmon_info[] = { + HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT), + NULL +}; + +static const struct hwmon_ops isl12022_hwmon_ops = { + .is_visible = isl12022_hwmon_is_visible, + .read = isl12022_hwmon_read, +}; + +static const struct hwmon_chip_info isl12022_hwmon_chip_info = { + .ops = &isl12022_hwmon_ops, + .info = isl12022_hwmon_info, +}; + +static void isl12022_hwmon_register(struct device *dev) +{ + struct isl12022 *isl12022; + struct device *hwmon; + int ret; + + if (!IS_REACHABLE(CONFIG_HWMON)) + return; + + isl12022 = dev_get_drvdata(dev); + + ret = regmap_update_bits(isl12022->regmap, ISL12022_REG_BETA, + ISL12022_BETA_TSE, ISL12022_BETA_TSE); + if (ret) { + dev_warn(dev, "unable to enable temperature sensor\n"); + return; + } + + hwmon = devm_hwmon_device_register_with_info(dev, "isl12022", isl12022, + &isl12022_hwmon_chip_info, + NULL); + if (IS_ERR(hwmon)) + dev_warn(dev, "unable to register hwmon device: %pe\n", hwmon); +} + /* * In the routines that deal directly with the isl12022 hardware, we use * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. @@ -160,6 +252,8 @@ static int isl12022_probe(struct i2c_client *client) return PTR_ERR(isl12022->regmap); } + isl12022_hwmon_register(&client->dev); + isl12022->rtc = devm_rtc_allocate_device(&client->dev); if (IS_ERR(isl12022->rtc)) return PTR_ERR(isl12022->rtc);