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[66.31.16.167]) by smtp.gmail.com with ESMTPSA id l13-20020a05620a28cd00b0070531c5d655sm2600676qkp.90.2023.01.19.13.39.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Jan 2023 13:39:31 -0800 (PST) From: Dennis Lambe Jr To: Alessandro Zummo , Alexandre Belloni , Krzysztof Kozlowski , Rob Herring , Atsushi Nemoto Cc: =?UTF-8?q?Myl=C3=A8ne=20Josserand?= , Gary Bisson , Javier Martinez Canillas , Troy Kisky , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rtc@vger.kernel.org, Dennis Lambe Jr Subject: [PATCH v3 1/3] rtc: m41t80: probe: use IS_ENABLED for CONFIG_OF Date: Thu, 19 Jan 2023 21:39:01 +0000 Message-Id: <20230119213903.899756-2-dennis@sparkcharge.io> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230119213903.899756-1-dennis@sparkcharge.io> References: <20230119213903.899756-1-dennis@sparkcharge.io> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The style guide recommends IS_ENABLED rather than ifdef for wrapping conditional code wherever possible. Functions that are only called on DeviceTree platforms would otherwise need to be cluttered up with __maybe_unused, which is especially undesirable if there's nothing inherently DT-specific about those functions. Signed-off-by: Dennis Lambe Jr --- Notes: v1 -> v2: spelling fix in changelog drivers/rtc/rtc-m41t80.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c index 494052dbd39f..f963b76e5fc0 100644 --- a/drivers/rtc/rtc-m41t80.c +++ b/drivers/rtc/rtc-m41t80.c @@ -909,10 +909,11 @@ static int m41t80_probe(struct i2c_client *client) if (IS_ERR(m41t80_data->rtc)) return PTR_ERR(m41t80_data->rtc); =20 -#ifdef CONFIG_OF - wakeup_source =3D of_property_read_bool(client->dev.of_node, - "wakeup-source"); -#endif + if (IS_ENABLED(CONFIG_OF)) { + wakeup_source =3D of_property_read_bool(client->dev.of_node, + "wakeup-source"); + } + if (client->irq > 0) { rc =3D devm_request_threaded_irq(&client->dev, client->irq, NULL, m41t80_handle_irq, --=20 2.25.1 From nobody Sun Sep 14 16:25:04 2025 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 5A3ACC46467 for ; Thu, 19 Jan 2023 22:02:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230043AbjASWCL (ORCPT ); Thu, 19 Jan 2023 17:02:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229969AbjASWBQ (ORCPT ); Thu, 19 Jan 2023 17:01:16 -0500 Received: from mail-qt1-x833.google.com (mail-qt1-x833.google.com [IPv6:2607:f8b0:4864:20::833]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 56EA658660 for ; Thu, 19 Jan 2023 13:39:39 -0800 (PST) Received: by mail-qt1-x833.google.com with SMTP id s4so2701411qtx.6 for ; Thu, 19 Jan 2023 13:39:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sparkcharge.io; 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=EvnEAnqblTBDjO4L9lAoJAikuecyCt30DJ9Jy9ahvAM=; b=XPjTivTM93RwFnsS/ljsxPX3656SstcIyCWz/ntXj5hdmpSndYugg7yxUcU6rdzkNk EwuLDbRZkZ8qW2KzsNRlPdkxWupoC7hlWR1jJNklPpyjVD42alTaXQI+g3JiTP9VtTUD fDpcf45LF78MkYjJCV/IE4LaUG58VDlzdifWa89+9+iHxv9carzoBVyCSj5k8fWTp2Pp YcgS/vM2TqoWHXRZS68OFmmwTntMELqVb1QETDAD6yFP6wtqeU2DP8CJC9Dqb4B3DV3C 6vLzxj4QRTUw2YTn8aBHMXlx3u2qLPyc+Zrp5YAloicoDCr3DfxWw7yXpoWNGrbVDkhQ 6GEA== 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=EvnEAnqblTBDjO4L9lAoJAikuecyCt30DJ9Jy9ahvAM=; b=LvfE67oh00SohG/GUoI33NHFK40NK3rJXInWgsFC++Eduzpke0xMDN5T2t5dm9v9H0 o0+fBvfjY1LoNEiJAcPgVot9DE870/RRwo50VUadFSRAqqBjQi8IK+b0isym5ozQ00b8 YaBEndttv4C2MgGp9Q2fLd2pmCRTmJx1cbroDRx6eKblb41FIva5dMeVeBiPAHBTS3wX 28KP45IEi7b7K+pbADR77XBEsyKB/EQBGh2XTNpMEfDc4MBCg7QSCgopqGPbdhLh9ziS KtzJeMEn5RL6FDoSaVkTY2UDkstei7B7D9O6bhiREv1O0RhxMTUsZhzvb4qmyqfy0spH f1eA== X-Gm-Message-State: AFqh2kpfYHQvF2tpgV+95hnnkCtCnwlcd1pwENiN4VYAPZlihKG30yIC KyjYk7Td84IoBWsEZgyoOELAMg== X-Google-Smtp-Source: AMrXdXvH05SRTIswgL/NPk4wgC7B25swx7vGDsNwIubApjxY3JniaRycLxhz6UZ1VXgRljC9SldxGQ== X-Received: by 2002:ac8:71c1:0:b0:3b6:3abd:fcc2 with SMTP id i1-20020ac871c1000000b003b63abdfcc2mr16964684qtp.46.1674164374360; Thu, 19 Jan 2023 13:39:34 -0800 (PST) Received: from localhost.localdomain (c-66-31-16-167.hsd1.ma.comcast.net. [66.31.16.167]) by smtp.gmail.com with ESMTPSA id l13-20020a05620a28cd00b0070531c5d655sm2600676qkp.90.2023.01.19.13.39.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Jan 2023 13:39:33 -0800 (PST) From: Dennis Lambe Jr To: Alessandro Zummo , Alexandre Belloni , Krzysztof Kozlowski , Rob Herring , Atsushi Nemoto Cc: =?UTF-8?q?Myl=C3=A8ne=20Josserand?= , Gary Bisson , Javier Martinez Canillas , Troy Kisky , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rtc@vger.kernel.org, Dennis Lambe Jr , Krzysztof Kozlowski Subject: [PATCH v3 2/3] dt-bindings: m41t80: add xtal load capacitance Date: Thu, 19 Jan 2023 21:39:02 +0000 Message-Id: <20230119213903.899756-3-dennis@sparkcharge.io> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230119213903.899756-1-dennis@sparkcharge.io> References: <20230119213903.899756-1-dennis@sparkcharge.io> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The ST m41t82 and m41t83 support programmable load capacitance from 3.5 pF to 17.4 pF. The hardware defaults to 12.5 pF. The accuracy of the xtal can be calibrated precisely by adjusting the load capacitance. Add default, minimum, and maximum for the standard rtc property quartz-load-femtofarads on compatible devices. Signed-off-by: Dennis Lambe Jr Reviewed-by: Krzysztof Kozlowski --- Notes: v2 -> v3: added "Reviewed-by: Krzysztof Kozlowski" to changelog =20 v1 -> v2: remove accidental wakeup-sources line suggested by Krzysztof Kozlowski spelling fix in changelog .../devicetree/bindings/rtc/st,m41t80.yaml | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/Documentation/devicetree/bindings/rtc/st,m41t80.yaml b/Documen= tation/devicetree/bindings/rtc/st,m41t80.yaml index fc9c6da6483f..6673adf6e99b 100644 --- a/Documentation/devicetree/bindings/rtc/st,m41t80.yaml +++ b/Documentation/devicetree/bindings/rtc/st,m41t80.yaml @@ -33,6 +33,11 @@ properties: "#clock-cells": const: 1 =20 + quartz-load-femtofarads: + default: 12500 + minimum: 3500 + maximum: 17375 + clock-output-names: maxItems: 1 description: From common clock binding to override the default output = clock name. @@ -46,6 +51,17 @@ properties: =20 allOf: - $ref: rtc.yaml + - if: + not: + properties: + compatible: + contains: + enum: + - st,m41t82 + - st,m41t83 + then: + properties: + quartz-load-femtofarads: false =20 unevaluatedProperties: false =20 --=20 2.25.1 From nobody Sun Sep 14 16:25:04 2025 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 98E7AC004D4 for ; Thu, 19 Jan 2023 22:02:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230167AbjASWCR (ORCPT ); Thu, 19 Jan 2023 17:02:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230032AbjASWBX (ORCPT ); Thu, 19 Jan 2023 17:01:23 -0500 Received: from mail-qt1-x829.google.com (mail-qt1-x829.google.com [IPv6:2607:f8b0:4864:20::829]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50056C380D for ; Thu, 19 Jan 2023 13:39:45 -0800 (PST) Received: by mail-qt1-x829.google.com with SMTP id z9so2705746qtv.5 for ; Thu, 19 Jan 2023 13:39:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sparkcharge.io; 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=jgeqi6RRPNuIjdr+16qci9xGfe9jHTKnAUBA+hjYEZ0=; b=EM5fiD7lxkWQV4cO85UqeJfo5w+/+GA2DxMmx4KyqmT7Ya6x/ZZDUCblPCkvNdy1wP eOnDdtzU7Dzhj7aBf5k4JCwJgaKhAEKpgFuiFm2+OZihWKRjm0AJK9SeGMigFFbSu7Np Dqf7+iOUcd/GbfnWuLKlBTs7KYKsrUOfr3SiRBFVr5cNIy459kiW9zegQ9VuwMdDpVqt PXcYxClPSEa8poQU4+FSqgQOscFd1R8EX+dEGCTII96FpWD/iryz8gKlwkRhASWv3YR9 V71zL2cBuKkZd6gpIWwpv8ityyo9feO7MpJ2QKjHFlnU4xFbgFhtj9AkIpRjyYY838YA V8rg== 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=jgeqi6RRPNuIjdr+16qci9xGfe9jHTKnAUBA+hjYEZ0=; b=S/YL554dmmMxbP1gti5s6pcRrfMu1lEUd6wgd+C7j+u/Ti4Jvsw7kL6ri1QJ39cbvX mlXLQIrS6KP6yPErQSVm8R6Cr6Wh3cMEgXMegT1J/XTH+nmEZ/wAo2WcPvebYaNMjlpi x2WBPblASjjICgt5rCpwihcHOov8ktqViUwmXsWRBq+bPY/pcf8zsv6bAbUAfO5TNrky CplHYoZYxNRu9AH+wThPGBRuLygBcY2Y3p7DbSye4h+eyHqr30WJGlKRra/LwOaW//xK aA21uK4ExOCMQhwR1CaF6S0ThPpe+MOSc7p7Z6EE8tOs2f+S5FUBpXD+2MWaQiw8iavC UCMQ== X-Gm-Message-State: AFqh2kozQ9kljWKwFAqbjKAkHy7KxtVrfnwaHJUOuvRyjxH+HEM+Kftk Ulb6pAFS1p785H5KXi8qW+lqAg== X-Google-Smtp-Source: AMrXdXtHHcZdlw6wPUTOUTPnLQ3VB2DUtwWDS/88v7sZM2nnU2rHJymWFvpGKOwx2VP9jbQaovN2Dg== X-Received: by 2002:ac8:4703:0:b0:3b6:2bbf:581e with SMTP id f3-20020ac84703000000b003b62bbf581emr17315557qtp.35.1674164382424; Thu, 19 Jan 2023 13:39:42 -0800 (PST) Received: from localhost.localdomain (c-66-31-16-167.hsd1.ma.comcast.net. [66.31.16.167]) by smtp.gmail.com with ESMTPSA id l13-20020a05620a28cd00b0070531c5d655sm2600676qkp.90.2023.01.19.13.39.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Jan 2023 13:39:42 -0800 (PST) From: Dennis Lambe Jr To: Alessandro Zummo , Alexandre Belloni , Krzysztof Kozlowski , Rob Herring , Atsushi Nemoto Cc: =?UTF-8?q?Myl=C3=A8ne=20Josserand?= , Gary Bisson , Javier Martinez Canillas , Troy Kisky , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rtc@vger.kernel.org, Dennis Lambe Jr Subject: [PATCH v3 3/3] rtc: m41t80: set xtal load capacitance from DT Date: Thu, 19 Jan 2023 21:39:03 +0000 Message-Id: <20230119213903.899756-4-dennis@sparkcharge.io> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230119213903.899756-1-dennis@sparkcharge.io> References: <20230119213903.899756-1-dennis@sparkcharge.io> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add support for specifying the xtal load capacitance in the DT node for devices with an Analog Calibration register. the m41t82 and m41t83 support xtal load capacitance from 3.5 pF to 17.4 pF. If no xtal load capacitance is specified, the battery-backed register won't be modified. The hardware defaults to 12.5 pF on reset. Signed-off-by: Dennis Lambe Jr --- drivers/rtc/rtc-m41t80.c | 75 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 71 insertions(+), 4 deletions(-) diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c index f963b76e5fc0..85bde7130a4d 100644 --- a/drivers/rtc/rtc-m41t80.c +++ b/drivers/rtc/rtc-m41t80.c @@ -44,12 +44,17 @@ #define M41T80_REG_ALARM_MIN 0x0d #define M41T80_REG_ALARM_SEC 0x0e #define M41T80_REG_FLAGS 0x0f +#define M41T80_REG_AC 0x12 #define M41T80_REG_SQW 0x13 =20 #define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1) #define M41T80_ALARM_REG_SIZE \ (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON) =20 +#define M41T80_AC_MIN 3500 +#define M41T80_AC_MAX 17375 +#define M41T80_AC_DEFAULT 12500 + #define M41T80_SQW_MAX_FREQ 32768 =20 #define M41T80_SEC_ST BIT(7) /* ST: Stop Bit */ @@ -68,6 +73,7 @@ #define M41T80_FEATURE_SQ BIT(2) /* Squarewave feature */ #define M41T80_FEATURE_WD BIT(3) /* Extra watchdog resolution */ #define M41T80_FEATURE_SQ_ALT BIT(4) /* RSx bits are in reg 4 */ +#define M41T80_FEATURE_AC BIT(5) /* Analog calibration */ =20 static const struct i2c_device_id m41t80_id[] =3D { { "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT }, @@ -75,8 +81,10 @@ static const struct i2c_device_id m41t80_id[] =3D { { "m41t80", M41T80_FEATURE_SQ }, { "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ}, { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, - { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, - { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, + { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ + | M41T80_FEATURE_AC }, + { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ + | M41T80_FEATURE_AC }, { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, @@ -108,11 +116,13 @@ static const __maybe_unused struct of_device_id m41t8= 0_of_match[] =3D { }, { .compatible =3D "st,m41t82", - .data =3D (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATUR= E_SQ) + .data =3D (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATUR= E_SQ + | M41T80_FEATURE_AC) }, { .compatible =3D "st,m41t83", - .data =3D (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATUR= E_SQ) + .data =3D (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATUR= E_SQ + | M41T80_FEATURE_AC) }, { .compatible =3D "st,m41t84", @@ -405,6 +415,54 @@ static const struct rtc_class_ops m41t80_rtc_ops =3D { .alarm_irq_enable =3D m41t80_alarm_irq_enable, }; =20 +static u8 to_sign_magnitude_u8(int n) +{ + if (n < 0) + return 0x80 | -n; + return n; +} + +static int m41t80_encode_ac(int quartz_load) +{ + if (quartz_load < M41T80_AC_MIN || quartz_load > M41T80_AC_MAX) + return -EINVAL; + + /* + * register representation is the per-capacitor offset from its default + * value in units of 1/4 pF, in sign-magnitude form. + */ + return to_sign_magnitude_u8((quartz_load - M41T80_AC_DEFAULT) / 125); +} + +static int m41t80_set_ac(struct m41t80_data *m41t80_data, int quartz_load) +{ + struct i2c_client *client =3D m41t80_data->client; + struct device *dev =3D &client->dev; + int ret; + int ac; + + if (!(m41t80_data->features & M41T80_FEATURE_AC)) { + dev_err(dev, "analog calibration requested but not supported\n"); + return -EOPNOTSUPP; + } + + ac =3D m41t80_encode_ac(quartz_load); + if (ac < 0) { + dev_err(dev, "quartz load %d fF out of range\n", + quartz_load); + return ac; + } + + ret =3D i2c_smbus_write_byte_data(client, M41T80_REG_AC, ac); + if (ret < 0) { + dev_err(dev, "Can't set AC register\n"); + return ret; + } + + dev_info(dev, "quartz load set to %d fF (AC=3D0x%x)\n", quartz_load, ac); + return 0; +} + #ifdef CONFIG_PM_SLEEP static int m41t80_suspend(struct device *dev) { @@ -883,6 +941,7 @@ static int m41t80_probe(struct i2c_client *client) struct rtc_time tm; struct m41t80_data *m41t80_data =3D NULL; bool wakeup_source =3D false; + u32 quartz_load =3D M41T80_AC_DEFAULT; =20 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_BYTE_DATA)) { @@ -912,6 +971,14 @@ static int m41t80_probe(struct i2c_client *client) if (IS_ENABLED(CONFIG_OF)) { wakeup_source =3D of_property_read_bool(client->dev.of_node, "wakeup-source"); + + rc =3D of_property_read_u32(client->dev.of_node, + "quartz-load-femtofarads", + &quartz_load); + if (!rc) + m41t80_set_ac(m41t80_data, quartz_load); + else if (rc !=3D -EINVAL) + dev_err(&client->dev, "quartz-load-femtofarads property value is missin= g or invalid\n"); } =20 if (client->irq > 0) { --=20 2.25.1