The MAX31790 has a tach input enable bit in each fan's configuration
register. This is only enabled by the driver if RPM mode is selected,
but the driver doesn't provide a way to independently enable tachometer
input regardless of the regulator mode.
By adding the fanN_enable sysfs files, we can decouple the tach input
from the regulator mode. Also update the documentation.
Signed-off-by: Justin Ledford <justinledford@xxxxxxxxxx>
---
Changes in v2:
- Removed updating fan_config during max31790_update_device
---
Documentation/hwmon/max31790.rst | 1 +
drivers/hwmon/max31790.c | 38 ++++++++++++++++++++++++++------
2 files changed, 32 insertions(+), 7 deletions(-)
diff --git a/Documentation/hwmon/max31790.rst b/Documentation/hwmon/max31790.rst
index 7b097c3b9b90..33c5c7330efc 100644
--- a/Documentation/hwmon/max31790.rst
+++ b/Documentation/hwmon/max31790.rst
@@ -38,6 +38,7 @@ Sysfs entries
fan[1-12]_input RO fan tachometer speed in RPM
fan[1-12]_fault RO fan experienced fault
fan[1-6]_target RW desired fan speed in RPM
+fan[1-6]_enable RW enable or disable the tachometer input
pwm[1-6]_enable RW regulator mode, 0=disabled (duty cycle=0%), 1=manual mode, 2=rpm mode
pwm[1-6] RW read: current pwm duty cycle,
write: target pwm duty cycle (0-255)
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
index 7e9362f6dc29..20bf5ffadefe 100644
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -202,6 +202,9 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel,
}
mutex_unlock(&data->update_lock);
return 0;
+ case hwmon_fan_enable:
+ *val = !!(data->fan_config[channel] & MAX31790_FAN_CFG_TACH_INPUT_EN);
+ return 0;
default:
return -EOPNOTSUPP;
}
@@ -214,7 +217,7 @@ static int max31790_write_fan(struct device *dev, u32 attr, int channel,
struct i2c_client *client = data->client;
int target_count;
int err = 0;
- u8 bits;
+ u8 bits, fan_config;
int sr;
mutex_lock(&data->update_lock);
@@ -243,6 +246,23 @@ static int max31790_write_fan(struct device *dev, u32 attr, int channel,
MAX31790_REG_TARGET_COUNT(channel),
data->target_count[channel]);
break;
+ case hwmon_fan_enable:
+ fan_config = data->fan_config[channel];
+ if (val == 0) {
+ fan_config &= ~MAX31790_FAN_CFG_TACH_INPUT_EN;
+ } else if (val == 1) {
+ fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN;
+ } else {
+ err = -EINVAL;
+ break;
+ }
+ if (fan_config != data->fan_config[channel]) {
+ err = i2c_smbus_write_byte_data(client, MAX31790_REG_FAN_CONFIG(channel),
+ fan_config);
+ if (!err)
+ data->fan_config[channel] = fan_config;
+ }
+ break;
default:
err = -EOPNOTSUPP;
break;
@@ -270,6 +290,10 @@ static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
!(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
return 0644;
return 0;
+ case hwmon_fan_enable:
+ if (channel < NR_CHANNEL)
+ return 0644;
+ return 0;
default:
return 0;
}
@@ -423,12 +447,12 @@ static umode_t max31790_is_visible(const void *data,
static const struct hwmon_channel_info *max31790_info[] = {
HWMON_CHANNEL_INFO(fan,
- HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
- HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
- HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
- HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
- HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
- HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+ HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
--
2.37.2.672.g94769d06f0-goog
