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From:   =?UTF-8?q?V=C3=A1clav=20Kubern=C3=A1t?= <kubernat@cesnet.cz>
To:     Jean Delvare <jdelvare@suse.com>,
        Guenter Roeck <linux@roeck-us.net>,
        Jonathan Corbet <corbet@lwn.net>, linux-hwmon@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     =?UTF-8?q?V=C3=A1clav=20Kubern=C3=A1t?= <kubernat@cesnet.cz>
Subject: [PATCH v5 3/5] hwmon: (max31790) Show 0 RPM/fault when input disabled
Date:   Wed, 12 May 2021 03:30:49 +0200
Message-Id: <20210512013052.903297-3-kubernat@cesnet.cz>
In-Reply-To: <20210512013052.903297-1-kubernat@cesnet.cz>
References: <20210512013052.903297-1-kubernat@cesnet.cz>
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When fan speed input is disabled, it makes no sense to show values in
fan*_input and fan*_fault.

Signed-off-by: Václav Kubernát <kubernat@cesnet.cz>
---
 drivers/hwmon/max31790.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
index 5d4c551df010..6e0ffbcf0d28 100644
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -165,6 +165,9 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel,
 
 	switch (attr) {
 	case hwmon_fan_input:
+		if (!(data->fan_config[channel] & MAX31790_FAN_CFG_TACH_INPUT_EN))
+			return -ENODATA;
+
 		tach = read_reg_word(regmap, MAX31790_REG_TACH_COUNT(channel));
 		if (tach < 0)
 			return tach;
@@ -179,6 +182,11 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel,
 		*val = RPM_FROM_REG(tach, get_tach_period(data->fan_dynamics[channel]));
 		return 0;
 	case hwmon_fan_fault:
+		if (!(data->fan_config[channel] & MAX31790_FAN_CFG_TACH_INPUT_EN)) {
+			*val = 0;
+			return 0;
+		}
+
 		if (channel > 6)
 			fault = read_reg_byte(regmap, MAX31790_REG_FAN_FAULT_STATUS2);
 		else
-- 
2.31.1