From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lf2-f13.google.com (mail-lf2-f13.google.com [74.125.229.205]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48F0243933F for ; Tue, 15 Sep 2026 17:13:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.229.205 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789492403; cv=none; b=SZ0mWoVwOHZNISFCEvq4D8NSCFffrGEeNi+GDS2dd4EySd937qcjsCr8p+pXoZmjWOijmm0l2qgV0k3Pe6nAUn5PvJGssetQygBj/oSnypHIOP7FTVpTIKybJJ1K0okBmktteSxVy7McrsobJLEv8VtJFLFmwfd6sYPYyjDnjO0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789492403; c=relaxed/simple; bh=2r0CGwnbhw+4LMmv7iYh/YHAix4sdwnKIMTStdJVtsM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=B4fTewnfzaFwdOsageRIUMMHBuSMdUhau6B14H3qnxgB6EQhoApyB4s1lgxqp5/2aN04uEz9w/DlS6bznrtZ9/ouWoK220whOk/RLD9k8yJAaiXObRtCb90C1L47UV81264ChEQd+TkkFJTBH8di4Gz/3ff1ZMA6niFGaC7FN6s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=ZM5sncDP; arc=none smtp.client-ip=74.125.229.205 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZM5sncDP" Received: by mail-lf2-f13.google.com with SMTP id 2adb3069b0e04-5b5e4f16f15so3930064e87.3 for ; Tue, 15 Sep 2026 10:13:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789492398; x=1790097198; darn=vger.kernel.org; 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:content-type; bh=qhwkJWnv59ZKHCv2u+n64jx0w7NQkxuLbLuAE4ou0xQ=; b=ZM5sncDP+8texOSeFeFr8gC/i1ugBafurUUBKpq9X/vwAlKsAvkhHOW6MWCpO2fa2c sTEB1RxuvSd3Svhx7joHNAdMR6v9QdrQrp9JWwbbBVyhKwaobng9HgXEkIK8b1ySZgLP T7XHyL4HqEYWnB3Stra3rvi610DcBkz3b7OwOfdMQzMHLILgv7T6ndWyNWEfRPdkLBj0 nZ/Zw8S5fmSrqV4/kL3Meovj1wxtTc5GzHhzy/XMVjg6mN+jU7AjwQXBkd8kPKl2fz9a 9aVSWemz43rUwMUZVYe1rZ7IKBS7ZPhknpzAdhGY8pPceaLRggPaAYYFutzWmlok156k ceBQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789492398; x=1790097198; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=qhwkJWnv59ZKHCv2u+n64jx0w7NQkxuLbLuAE4ou0xQ=; b=CXnqkkizfpFqeOmcwEhTG+FiRD0dIHoXjsCU1bDeDMZJ9ajd/+920uXSCNwM+s3kCf 50ERFoWCnJ4DHaw4ktlSlwUogn7s/UyzlaRcQNcWMtpan6loblvJL1D444Y15B8mjKB4 hi7pPaPyMmFPy1IxT8ymVKQrSL6BvQ19FOQdohtegiELLBblQUgkt3llREXSsO9FWCcG i83tsWour1JYWaKfw5ru5N+xvZqT1Bwx5dPgfd8FLXd3hfqcjX1tTUi5LHKrV8Tkmto2 HYmt0GO87cuKPj0nD0xJ8dWwlGJf5d3vlNPf8lTBrv+OEhP2cKnQrLK83cTLsAd3i6GV p4sg== X-Forwarded-Encrypted: i=1; AKwUvBwhchZ+DRShwfv+gzmJQIfaOhvCdBvg5hMR88JFt81KxP1wUFqeltN82EXvcLQFuwufm/O9UmLsyURJ@vger.kernel.org X-Gm-Message-State: AFuF++mjZ1PEAt5E/cDK/WMthKido7o8txcFTebadvUIqgPMQtIoRoG6 vVyWtq3B7ciLY/58Jm+G/NcaqrkPQp/RnGuZLPzG4e/PClQaIr3ucsA= X-Gm-Gg: AYBFou0LB34BzpDXh8YGe8LeioQKRaPVkx583x1c/gw9Db74zzQ4dIoEk4DTYQ7SjVG vRKQt5YCcMdUI4HCBmV896OKmSDjlwbeDpyAEYyNoA6h5/izepHOwRGBcSekH7oFm6Mz5hOXrBU fzEwm/Hb+3uhqfG6DSwxP1TMS3lo9KEG9G5l4CrVYsB//PjTs3ZOxkO7ViFKSm5DTOPGDAkb352 CVMCk+QKbxm4LVFbsuCOccauzb371zIrYfO5eO6qlay7ACNPAVlTIshMcEay02OwqWDjt0reVIe FqW+2tnHTB2kbOrEiPeAMLArLagzw48Q8Pb8hGwRHibdALT7kkZBJK5Fkap8jxOTl/bBamcic+E NLDt2R5mg5Y72vRmAbiXp5pE+xURQfzsj/1ZrVFODGGgAss4gafEQHJiPvXJ9mvkuSH3XHubYFU D+HRyHbCNlXOVF5bDRCSeRF0fDKmSHKKXyaAkX1SnuGxnOn10BNgW0rYDMuy2vGA== X-Received: by 2002:a05:6512:3a96:b0:5b6:19fe:a5a9 with SMTP id 2adb3069b0e04-5b8ae6b8986mr4523493e87.26.1789492397996; Tue, 15 Sep 2026 10:13:17 -0700 (PDT) Received: from fedora ([46.8.219.5]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-5b8b57eb908sm91791e87.79.2026.09.15.10.13.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Sep 2026 10:13:17 -0700 (PDT) From: Vitaliy Sochnev To: "Rafael J. Wysocki" , Daniel Lezcano Cc: Zhang Rui , Lukasz Luba , Christian Marangi , Lorenzo Bianconi , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Vitaliy Sochnev Subject: [PATCH v2 2/4] thermal/drivers/airoha: Serialise access to the shared ADC Date: Tue, 15 Sep 2026 20:11:29 +0100 Message-ID: <20260915191131.25214-3-sochnev.v.74@gmail.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260915191131.25214-1-sochnev.v.74@gmail.com> References: <20260915191131.25214-1-sochnev.v.74@gmail.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit A read selects the sensor and walks three diodes with a 10 ms settle on each. Nothing serialises this, so concurrent reads interleave and convert samples taken at another mux position. Mux writes are dropped silently unless PLLRG_PROTECT is lifted, and its save and restore do not nest. The cached TADC value also skips a write after another reader has moved the mux. With the AN7583 sensors read as parallel zones during CPU frequency changes, a zone crossed its critical trip on a chip at 55 C and the board shut down. Serialise the sequence, drop the cache, check the selection after writing and after sampling, and return -EAGAIN if it does not hold. Signed-off-by: Vitaliy Sochnev --- drivers/thermal/airoha_thermal.c | 85 +++++++++++++++++++++++++------- 1 file changed, 68 insertions(+), 17 deletions(-) diff --git a/drivers/thermal/airoha_thermal.c b/drivers/thermal/airoha_thermal.c index 2934d6aba0ed..d7e4a088b7ea 100644 --- a/drivers/thermal/airoha_thermal.c +++ b/drivers/thermal/airoha_thermal.c @@ -5,6 +5,7 @@ #include #include #include +#include #include #include #include @@ -191,6 +192,7 @@ #define AN7583_NUM_SENSOR 3 #define AIROHA_THERMAL_NO_MUX_SENSOR -1 +#define AIROHA_THERMAL_MUX_TRIES 3 /* Convert temp to raw value as read from ADC ((((temp / 100) - init) * slope) / 1000) + offset */ #define TEMP_TO_RAW(priv, temp) ((((((temp) / 100) - (priv)->init_temp) * \ @@ -250,7 +252,8 @@ struct airoha_thermal_priv { struct resource scu_adc_res; u32 pllrg_protect; - int current_adc; + /* Serialises mux selection and ADC sampling */ + struct mutex lock; struct thermal_zone_device *tz; int init_temp; @@ -294,9 +297,26 @@ static int airoha_get_thermal_ADC(struct airoha_thermal_priv *priv) return val; } +static bool airoha_thermal_mux_holds(struct airoha_thermal_priv *priv, + int tdac_idx, int sensor_idx) +{ + unsigned int val; + + if (regmap_field_read(priv->chip_scu_fields[AIROHA_THERMAL_MUX_TADC], &val) || + val != tdac_idx) + return false; + + if (sensor_idx == AIROHA_THERMAL_NO_MUX_SENSOR) + return true; + + return !regmap_field_read(priv->chip_scu_fields[AIROHA_THERMAL_MUX_SENSOR], &val) && + val == sensor_idx; +} + static void airoha_set_thermal_mux(struct airoha_thermal_priv *priv, int tdac_idx, int sensor_idx) { + int tries = AIROHA_THERMAL_MUX_TRIES; u32 pllrg; /* Save PLLRG current value */ @@ -307,19 +327,17 @@ static void airoha_set_thermal_mux(struct airoha_thermal_priv *priv, priv->pllrg_protect); /* - * Configure Thermal Sensor mux to sensor_idx. + * Configure Thermal Sensor mux to sensor_idx and Thermal ADC mux to + * tdac_idx. Writes can be dropped silently, so read them back. * (if not supported, sensor_idx is AIROHA_THERMAL_NO_MUX_SENSOR) */ - if (sensor_idx != AIROHA_THERMAL_NO_MUX_SENSOR) - regmap_field_write(priv->chip_scu_fields[AIROHA_THERMAL_MUX_SENSOR], - sensor_idx); - - /* Configure Thermal ADC mux to tdac_idx */ - if (priv->current_adc != tdac_idx) { + do { + if (sensor_idx != AIROHA_THERMAL_NO_MUX_SENSOR) + regmap_field_write(priv->chip_scu_fields[AIROHA_THERMAL_MUX_SENSOR], + sensor_idx); regmap_field_write(priv->chip_scu_fields[AIROHA_THERMAL_MUX_TADC], tdac_idx); - priv->current_adc = tdac_idx; - } + } while (!airoha_thermal_mux_holds(priv, tdac_idx, sensor_idx) && --tries); /* Restore PLLRG value on exit */ regmap_write(priv->chip_scu, EN7581_PLLRG_PROTECT, pllrg); @@ -594,12 +612,40 @@ static int en7581_thermal_post_probe(struct platform_device *pdev) return 0; } +static int an7583_thermal_read_diode(struct airoha_thermal_priv *priv, + int diode, int sensor_idx, int *val) +{ + airoha_set_thermal_mux(priv, diode, sensor_idx); + *val = airoha_get_thermal_ADC(priv); + + return airoha_thermal_mux_holds(priv, diode, sensor_idx) ? 0 : -EAGAIN; +} + +static int an7583_thermal_read_diodes(struct airoha_thermal_priv *priv, + int sensor_idx, int *zero, int *d0, + int *d1) +{ + int ret; + + ret = an7583_thermal_read_diode(priv, AN7583_ZERO_TADC, sensor_idx, zero); + if (ret) + return ret; + + ret = an7583_thermal_read_diode(priv, AN7583_D0_TADC, sensor_idx, d0); + if (ret) + return ret; + + return an7583_thermal_read_diode(priv, AN7583_D1_TADC, sensor_idx, d1); +} + static int an7583_thermal_get_temp(struct thermal_zone_device *tz, int *temp) { struct airoha_thermal_priv *priv = thermal_zone_device_priv(tz); int sensor_idx; int delta_diode, delta_gain; int coeff, slope, offset; + int tries = AIROHA_THERMAL_MUX_TRIES; + int ret; int diode_zero, diode_d0, diode_d1; @@ -610,12 +656,14 @@ static int an7583_thermal_get_temp(struct thermal_zone_device *tz, int *temp) slope = an7583_thermal_slope[sensor_idx]; offset = an7583_thermal_offset[sensor_idx]; - airoha_set_thermal_mux(priv, AN7583_ZERO_TADC, sensor_idx); - diode_zero = airoha_get_thermal_ADC(priv); - airoha_set_thermal_mux(priv, AN7583_D0_TADC, sensor_idx); - diode_d0 = airoha_get_thermal_ADC(priv); - airoha_set_thermal_mux(priv, AN7583_D1_TADC, sensor_idx); - diode_d1 = airoha_get_thermal_ADC(priv); + mutex_lock(&priv->lock); + do { + ret = an7583_thermal_read_diodes(priv, sensor_idx, &diode_zero, + &diode_d0, &diode_d1); + } while (ret == -EAGAIN && --tries); + mutex_unlock(&priv->lock); + if (ret) + return ret; delta_diode = diode_d1 - diode_d0; delta_gain = (delta_diode * coeff) / 100 + (diode_zero - diode_d1); @@ -676,7 +724,10 @@ static int airoha_thermal_probe(struct platform_device *pdev) return -ENOMEM; priv->pllrg_protect = soc_data->pllrg_protect; - priv->current_adc = -1; + + ret = devm_mutex_init(dev, &priv->lock); + if (ret) + return ret; if (!soc_data->probe) return -EINVAL; -- 2.55.0