On Monday 27 September 2021 00:10:43 W_Armin@xxxxxx wrote:
> From: Armin Wolf <W_Armin@xxxxxx>
>
> The nominal speed of each fan can be obtained with
> i8k_get_fan_nominal_speed(), however the result is not available
> from userspace.
> Change that by adding fanX_min, fanX_max and fanX_target attributes.
> All are RO since fan control happens over pwm.
>
> Tested on a Dell Inspiron 3505 and a Dell Latitude C600.
>
> Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
Reviewed-by: Pali Rohár <pali@xxxxxxxxxx>
> ---
> Documentation/hwmon/dell-smm-hwmon.rst | 3 ++
> drivers/hwmon/dell-smm-hwmon.c | 61 +++++++++++++++++++++++---
> 2 files changed, 58 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/hwmon/dell-smm-hwmon.rst b/Documentation/hwmon/dell-smm-hwmon.rst
> index 3bf77a5df995..beec88491171 100644
> --- a/Documentation/hwmon/dell-smm-hwmon.rst
> +++ b/Documentation/hwmon/dell-smm-hwmon.rst
> @@ -34,6 +34,9 @@ Name Perm Description
> =============================== ======= =======================================
> fan[1-3]_input RO Fan speed in RPM.
> fan[1-3]_label RO Fan label.
> +fan[1-3]_min RO Minimal Fan speed in RPM
> +fan[1-3]_max RO Maximal Fan speed in RPM
> +fan[1-3]_target RO Expected Fan speed in RPM
> pwm[1-3] RW Control the fan PWM duty-cycle.
> pwm1_enable WO Enable or disable automatic BIOS fan
> control (not supported on all laptops,
> diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
> index 774c1b0715d9..476f2a74bd8c 100644
> --- a/drivers/hwmon/dell-smm-hwmon.c
> +++ b/drivers/hwmon/dell-smm-hwmon.c
> @@ -76,6 +76,7 @@ struct dell_smm_data {
> int temp_type[DELL_SMM_NO_TEMP];
> bool fan[DELL_SMM_NO_FANS];
> int fan_type[DELL_SMM_NO_FANS];
> + int *fan_nominal_speed[DELL_SMM_NO_FANS];
> };
>
> MODULE_AUTHOR("Massimo Dal Zotto (dz@xxxxxxxxxx)");
> @@ -673,6 +674,13 @@ static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types
> if (data->fan[channel] && !data->disallow_fan_type_call)
> return 0444;
>
> + break;
> + case hwmon_fan_min:
> + case hwmon_fan_max:
> + case hwmon_fan_target:
> + if (data->fan_nominal_speed[channel])
> + return 0444;
> +
> break;
> default:
> break;
> @@ -740,6 +748,25 @@ static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 a
>
> *val = ret;
>
> + return 0;
> + case hwmon_fan_min:
> + *val = data->fan_nominal_speed[channel][0];
> +
> + return 0;
> + case hwmon_fan_max:
> + *val = data->fan_nominal_speed[channel][data->i8k_fan_max];
> +
> + return 0;
> + case hwmon_fan_target:
> + ret = i8k_get_fan_status(data, channel);
> + if (ret < 0)
> + return ret;
> +
> + if (ret > data->i8k_fan_max)
> + ret = data->i8k_fan_max;
> +
> + *val = data->fan_nominal_speed[channel][ret];
> +
> return 0;
> default:
> break;
> @@ -889,9 +916,12 @@ static const struct hwmon_channel_info *dell_smm_info[] = {
> HWMON_T_INPUT | HWMON_T_LABEL
> ),
> HWMON_CHANNEL_INFO(fan,
> - HWMON_F_INPUT | HWMON_F_LABEL,
> - HWMON_F_INPUT | HWMON_F_LABEL,
> - HWMON_F_INPUT | HWMON_F_LABEL
> + HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
> + HWMON_F_TARGET,
> + HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
> + HWMON_F_TARGET,
> + HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
> + HWMON_F_TARGET
> ),
> HWMON_CHANNEL_INFO(pwm,
> HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
> @@ -910,7 +940,7 @@ static int __init dell_smm_init_hwmon(struct device *dev)
> {
> struct dell_smm_data *data = dev_get_drvdata(dev);
> struct device *dell_smm_hwmon_dev;
> - int i, err;
> + int i, state, err;
>
> for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
> data->temp_type[i] = i8k_get_temp_type(i);
> @@ -926,8 +956,27 @@ static int __init dell_smm_init_hwmon(struct device *dev)
> err = i8k_get_fan_status(data, i);
> if (err < 0)
> err = i8k_get_fan_type(data, i);
> - if (err >= 0)
> - data->fan[i] = true;
> +
> + if (err < 0)
> + continue;
> +
> + data->fan[i] = true;
> + data->fan_nominal_speed[i] = devm_kmalloc_array(dev, data->i8k_fan_max + 1,
> + sizeof(*data->fan_nominal_speed[i]),
> + GFP_KERNEL);
> + if (!data->fan_nominal_speed[i])
> + continue;
> +
> + for (state = 0; state <= data->i8k_fan_max; state++) {
> + err = i8k_get_fan_nominal_speed(data, i, state);
> + if (err < 0) {
> + /* Mark nominal speed table as invalid in case of error */
> + devm_kfree(dev, data->fan_nominal_speed[i]);
> + data->fan_nominal_speed[i] = NULL;
> + break;
> + }
> + data->fan_nominal_speed[i][state] = err;
> + }
> }
>
> dell_smm_hwmon_dev = devm_hwmon_device_register_with_info(dev, "dell_smm", data,
> --
> 2.20.1
>
