summaryrefslogtreecommitdiff
path: root/drivers/hwmon/max31790.c
diff options
context:
space:
mode:
authorGuenter Roeck <linux@roeck-us.net>2021-05-26 18:40:20 +0300
committerGuenter Roeck <linux@roeck-us.net>2021-06-17 14:21:46 +0300
commit2013607b85f03ff24a5a19933705905a1b324a31 (patch)
tree07f2a2fef95139bd5e97d111cd5caedd3ceb9899 /drivers/hwmon/max31790.c
parent148c847c9e5a54b99850617bf9c143af9a344f92 (diff)
downloadlinux-2013607b85f03ff24a5a19933705905a1b324a31.tar.xz
hwmon: (max31790) Clear fan fault after reporting it
Fault bits in MAX31790 are sticky and have to be cleared explicitly. A write operation into either the 'Target Duty Cycle' register or the 'Target Count' register is necessary to clear a fault. At the same time, we can never clear cached fault status values before reading them because the companion fault status for any given fan is cleared as well when clearing a fault. Cc: Jan Kundrát <jan.kundrat@cesnet.cz> Cc: Václav Kubernát <kubernat@cesnet.cz> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Václav Kubernát <kubernat@cesnet.cz> Link: https://lore.kernel.org/r/20210526154022.3223012-6-linux@roeck-us.net
Diffstat (limited to 'drivers/hwmon/max31790.c')
-rw-r--r--drivers/hwmon/max31790.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
index 67677c437768..7927468c5271 100644
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -80,7 +80,7 @@ static struct max31790_data *max31790_update_device(struct device *dev)
MAX31790_REG_FAN_FAULT_STATUS1);
if (rv < 0)
goto abort;
- data->fault_status = rv & 0x3F;
+ data->fault_status |= rv & 0x3F;
rv = i2c_smbus_read_byte_data(client,
MAX31790_REG_FAN_FAULT_STATUS2);
@@ -181,7 +181,21 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel,
*val = rpm;
return 0;
case hwmon_fan_fault:
+ mutex_lock(&data->update_lock);
*val = !!(data->fault_status & (1 << channel));
+ data->fault_status &= ~(1 << channel);
+ /*
+ * If a fault bit is set, we need to write into one of the fan
+ * configuration registers to clear it. Note that this also
+ * clears the fault for the companion channel if enabled.
+ */
+ if (*val) {
+ int reg = MAX31790_REG_TARGET_COUNT(channel % NR_CHANNEL);
+
+ i2c_smbus_write_byte_data(data->client, reg,
+ data->target_count[channel % NR_CHANNEL] >> 8);
+ }
+ mutex_unlock(&data->update_lock);
return 0;
default:
return -EOPNOTSUPP;