On Mon, Aug 29, 2022 at 02:43:51AM +0000, Justin Ledford wrote:
> 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>
> ---
> Documentation/hwmon/max31790.rst | 1 +
> drivers/hwmon/max31790.c | 44 +++++++++++++++++++++++++++-----
> 2 files changed, 38 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..3ae02be4b41e 100644
> --- a/drivers/hwmon/max31790.c
> +++ b/drivers/hwmon/max31790.c
> @@ -118,6 +118,12 @@ static struct max31790_data *max31790_update_device(struct device *dev)
> goto abort;
> data->target_count[i] = rv;
> }
> +
> + rv = i2c_smbus_read_byte_data(client,
> + MAX31790_REG_FAN_CONFIG(i));
> + if (rv < 0)
> + goto abort;
> + data->fan_config[i] = rv;
Why is this needed ?
Guenter
> }
>
> data->last_updated = jiffies;
> @@ -202,6 +208,9 @@ 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 +223,7 @@ 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 +252,23 @@ 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 +296,10 @@ 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 +453,12 @@ 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
>
