From mboxrd@z Thu Jan 1 00:00:00 1970 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 D249AC433EF for ; Wed, 25 May 2022 13:58:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244607AbiEYN6e (ORCPT ); Wed, 25 May 2022 09:58:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244608AbiEYN62 (ORCPT ); Wed, 25 May 2022 09:58:28 -0400 Received: from mail-oa1-x34.google.com (mail-oa1-x34.google.com [IPv6:2001:4860:4864:20::34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B28BA88B8; Wed, 25 May 2022 06:58:24 -0700 (PDT) Received: by mail-oa1-x34.google.com with SMTP id 586e51a60fabf-f2c8c0d5bdso1264028fac.4; Wed, 25 May 2022 06:58:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=iHeaF4qvR8W10l3XF9HQVODR5ZGAlxmNzSKfdN0dyPo=; b=L9BNg9IGCAAEBU75yplClteKFTWUAo+XJPAiHOloRNlM6bA3ABMrjmSbit6VGilKQt 5btzFqSfjkzBKRCwrvSyjY5Bj4KMoykBoSvsifmH4ZuiVj9bwNx0fYFwPJFtlfjV3+Tq LkyzHIWszFL7xY1p+5t9B9BHk5bWJ1CayxsuCEjkfArLQlZX0ebRAuSGd7tDy+scBJc5 rr7+VXvweP8d5U4AULcdUHKNAlpxrPgjIm1ltWYIko7ioTR5WyX0qYTqz93selw4womJ tfEuCuJacj6UtfEFZqzQuS6eQ+8tpQklYa2dKPCUdq0gdJGpKh5N04P1FKU6vzRzyG1R obdg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=iHeaF4qvR8W10l3XF9HQVODR5ZGAlxmNzSKfdN0dyPo=; b=BmdcFnEhzwrtmTyjh78HBNXQc9mD/n2E87B8c+1nsZ0Q7pGmIHWbdAMJmTvDH0yE22 lg7xOcIvmrbaND3ksdbSTftNLKlmm56jHdaTe4412cY5tqKrX4GlaPrb6YhEfQTfT9Ae +380rgPfGAkms5YpShmHL5TI6qGPtmhevGn6T3o7k1qGzspou8ra4ybu9Y7xYkTUr4cb LIrxzM130OI0BPIE9nAmihUSAcBEvsBJXWjO7yebuVHDWONicdR1AwlEdW4ztvHaLF/w +28Z2ot9OkMohjJR4zKHidfopp1qITc3clIU5iBz0t5+peJPjGXhIQfF21hYjj4nfPY9 CYAg== X-Gm-Message-State: AOAM532drB95880ScsqGliymgrSVSXZ19+axQNlpcQlxeAYdhETlyKz+ OmdEDwoAM6e2odPMDxk+XOPq4pItYyXiJw== X-Google-Smtp-Source: ABdhPJwnR/sS4OKH8+WNV2EFXv4UHyB7+AfQmrs2RGSwtyP4kYSiXU3VgplUqzcEiDaNl9/vkqFEnA== X-Received: by 2002:a05:6870:b254:b0:ec:6ca4:c89f with SMTP id b20-20020a056870b25400b000ec6ca4c89fmr5801560oam.272.1653487103094; Wed, 25 May 2022 06:58:23 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id o9-20020a4ad149000000b0035eb4e5a6b2sm6551198oor.8.2022.05.25.06.58.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 May 2022 06:58:22 -0700 (PDT) Sender: Guenter Roeck From: Guenter Roeck To: linux-hwmon@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Jean Delvare , Slawomir Stepien , Guenter Roeck Subject: [PATCH 11/40] hwmon: (lm90) Add support for unsigned and signed temperatures Date: Wed, 25 May 2022 06:57:29 -0700 Message-Id: <20220525135758.2944744-12-linux@roeck-us.net> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220525135758.2944744-1-linux@roeck-us.net> References: <20220525135758.2944744-1-linux@roeck-us.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org ADT7461 and TMP451 temperature sensors support extended temperature ranges. If standard temperature range is selected, the temperature range is unsigned and limited to 0 .. 127 degrees C. For TMP461, the standard temperature range is -128000 ... 127000 degrees C. Distinguish between the two chips by introducing a feature flag indicating if the standard temperature range is signed or unsigned. Use the same flag for MAX6646/ MAX6647 as well since those chips also support unsigned temperatures. Note that while the datasheet for ADT7461 suggests that the default temperature range is unsigned, tests with a real chip suggest that this is not the case: If the temperature offset is set to a value << 0, the temperature register does report negative values. Tests with real chips show that MAX6680/MAX6681 and SA56004 report temperatures of 128 degrees C and higher as negative temperatures. Add respective comments to the code. Also use clamp_val() and DIV_ROUND_CLOSEST where appropriate in calculations. Signed-off-by: Guenter Roeck --- drivers/hwmon/lm90.c | 70 ++++++++++++++++++++++++++------------------ 1 file changed, 42 insertions(+), 28 deletions(-) diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c index 42e72702b9a9..acb9ca3b99b0 100644 --- a/drivers/hwmon/lm90.c +++ b/drivers/hwmon/lm90.c @@ -170,6 +170,7 @@ enum chips { adm1032, adt7461, adt7461a, g781, lm86, lm90, lm99, #define LM90_FLAG_ADT7461_EXT BIT(0) /* ADT7461 extended mode */ /* Device features */ #define LM90_HAVE_OFFSET BIT(1) /* temperature offset register */ +#define LM90_HAVE_UNSIGNED_TEMP BIT(2) /* temperatures are unsigned */ #define LM90_HAVE_REM_LIMIT_EXT BIT(3) /* extended remote limit */ #define LM90_HAVE_EMERGENCY BIT(4) /* 3rd upper (emergency) limit */ #define LM90_HAVE_EMERGENCY_ALARM BIT(5)/* emergency alarm */ @@ -354,6 +355,11 @@ static const struct lm90_params lm90_params[] = { .max_convrate = 10, }, [adt7461] = { + /* + * Standard temperature range is supposed to be unsigned, + * but that does not match reality. Negative temperatures + * are always reported. + */ .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_EXTENDED_TEMP | LM90_HAVE_CRIT | LM90_HAVE_PARTIAL_PEC, @@ -392,7 +398,8 @@ static const struct lm90_params lm90_params[] = { .max_convrate = 9, }, [max6646] = { - .flags = LM90_HAVE_CRIT | LM90_HAVE_BROKEN_ALERT, + .flags = LM90_HAVE_CRIT | LM90_HAVE_BROKEN_ALERT + | LM90_HAVE_UNSIGNED_TEMP, .alert_alarms = 0x7c, .max_convrate = 6, .reg_local_ext = MAX6657_REG_LOCAL_TEMPL, @@ -416,6 +423,11 @@ static const struct lm90_params lm90_params[] = { .reg_local_ext = MAX6657_REG_LOCAL_TEMPL, }, [max6680] = { + /* + * Apparent temperatures of 128 degrees C or higher are reported + * and treated as negative temperatures (meaning min_alarm will + * be set). + */ .flags = LM90_HAVE_OFFSET | LM90_HAVE_CRIT | LM90_HAVE_CRIT_ALRM_SWP | LM90_HAVE_BROKEN_ALERT, .alert_alarms = 0x7c, @@ -434,6 +446,11 @@ static const struct lm90_params lm90_params[] = { .max_convrate = 8, }, [sa56004] = { + /* + * Apparent temperatures of 128 degrees C or higher are reported + * and treated as negative temperatures (meaning min_alarm will + * be set). + */ .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT | LM90_HAVE_CRIT, .alert_alarms = 0x7b, .max_convrate = 9, @@ -441,7 +458,8 @@ static const struct lm90_params lm90_params[] = { }, [tmp451] = { .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT - | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_EXTENDED_TEMP | LM90_HAVE_CRIT, + | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_EXTENDED_TEMP | LM90_HAVE_CRIT + | LM90_HAVE_UNSIGNED_TEMP, .alert_alarms = 0x7c, .max_convrate = 9, .reg_local_ext = TMP451_REG_LOCAL_TEMPL, @@ -1118,33 +1136,27 @@ static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val) static u8 temp_to_u8_adt7461(struct lm90_data *data, long val) { if (data->flags & LM90_FLAG_ADT7461_EXT) { - if (val <= -64000) - return 0; - if (val >= 191000) - return 0xFF; - return (val + 500 + 64000) / 1000; + val = clamp_val(val, -64000, 191000); + val += 64000; + } else if (data->flags & LM90_HAVE_UNSIGNED_TEMP) { + val = clamp_val(val, 0, 127000); + } else { + val = clamp_val(val, -128000, 127000); } - if (val <= 0) - return 0; - if (val >= 127000) - return 127; - return (val + 500) / 1000; + return DIV_ROUND_CLOSEST(val, 1000); } static u16 temp_to_u16_adt7461(struct lm90_data *data, long val) { if (data->flags & LM90_FLAG_ADT7461_EXT) { - if (val <= -64000) - return 0; - if (val >= 191750) - return 0xFFC0; - return (val + 64000 + 125) / 250 * 64; + val = clamp_val(val, -64000, 191000); + val += 64000; + } else if (data->flags & LM90_HAVE_UNSIGNED_TEMP) { + val = clamp_val(val, 0, 127000); + } else { + val = clamp_val(val, -128000, 127000); } - if (val <= 0) - return 0; - if (val >= 127750) - return 0x7FC0; - return (val + 125) / 250 * 64; + return DIV_ROUND_CLOSEST(val, 1000) & 0xfff0; } /* pec used for devices with PEC support */ @@ -1190,7 +1202,7 @@ static int lm90_get_temp11(struct lm90_data *data, int index) if (data->flags & LM90_HAVE_EXTENDED_TEMP) temp = temp_from_u16_adt7461(data, temp11); - else if (data->kind == max6646) + else if (data->flags & LM90_HAVE_UNSIGNED_TEMP) temp = temp_from_u16(temp11); else temp = temp_from_s16(temp11); @@ -1227,7 +1239,7 @@ static int lm90_set_temp11(struct lm90_data *data, int index, long val) if (data->flags & LM90_HAVE_EXTENDED_TEMP) data->temp11[index] = temp_to_u16_adt7461(data, val); - else if (data->kind == max6646) + else if (data->flags & LM90_HAVE_UNSIGNED_TEMP) data->temp11[index] = temp_to_u8(val) << 8; else if (data->flags & LM90_HAVE_REM_LIMIT_EXT) data->temp11[index] = temp_to_s16(val); @@ -1253,7 +1265,7 @@ static int lm90_get_temp8(struct lm90_data *data, int index) if (data->flags & LM90_HAVE_EXTENDED_TEMP) temp = temp_from_u8_adt7461(data, temp8); - else if (data->kind == max6646) + else if (data->flags & LM90_HAVE_UNSIGNED_TEMP) temp = temp_from_u8(temp8); else temp = temp_from_s8(temp8); @@ -1289,7 +1301,7 @@ static int lm90_set_temp8(struct lm90_data *data, int index, long val) if (data->flags & LM90_HAVE_EXTENDED_TEMP) data->temp8[index] = temp_to_u8_adt7461(data, val); - else if (data->kind == max6646) + else if (data->flags & LM90_HAVE_UNSIGNED_TEMP) data->temp8[index] = temp_to_u8(val); else data->temp8[index] = temp_to_s8(val); @@ -1307,7 +1319,7 @@ static int lm90_get_temphyst(struct lm90_data *data, int index) if (data->flags & LM90_HAVE_EXTENDED_TEMP) temp = temp_from_u8_adt7461(data, data->temp8[index]); - else if (data->kind == max6646) + else if (data->flags & LM90_HAVE_UNSIGNED_TEMP) temp = temp_from_u8(data->temp8[index]); else temp = temp_from_s8(data->temp8[index]); @@ -1326,7 +1338,7 @@ static int lm90_set_temphyst(struct lm90_data *data, long val) if (data->flags & LM90_HAVE_EXTENDED_TEMP) temp = temp_from_u8_adt7461(data, data->temp8[LOCAL_CRIT]); - else if (data->kind == max6646) + else if (data->flags & LM90_HAVE_UNSIGNED_TEMP) temp = temp_from_u8(data->temp8[LOCAL_CRIT]); else temp = temp_from_s8(data->temp8[LOCAL_CRIT]); @@ -1901,6 +1913,8 @@ static int lm90_init_client(struct i2c_client *client, struct lm90_data *data) * Put MAX6680/MAX8881 into extended resolution (bit 0x10, * 0.125 degree resolution) and range (0x08, extend range * to -64 degree) mode for the remote temperature sensor. + * Note that expeciments with an actual chip do not show a difference + * if bit 3 is set or not. */ if (data->kind == max6680) config |= 0x18; -- 2.35.1