Commit b1986c8e authored by Armin Wolf's avatar Armin Wolf Committed by Guenter Roeck
Browse files

hwmon: (dell-smm) Add support for fanX_min, fanX_max and fanX_target 



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: default avatarArmin Wolf <W_Armin@gmx.de>
Reviewed-by: default avatarPali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20210926221044.14327-2-W_Armin@gmx.de


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 51369c0f

Documentation/hwmon/dell-smm-hwmon.rst

+3 −0
Original line number Diff line number Diff line
@@ -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,

drivers/hwmon/dell-smm-hwmon.c

+55 −6
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ 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@debian.org)");
@@ -671,6 +672,13 @@ 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;
@@ -738,6 +746,25 @@ 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;
@@ -887,9 +914,12 @@ 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,
@@ -908,7 +938,7 @@ 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);
@@ -924,8 +954,27 @@ 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)



		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,