Smart Fan Control

Supports to control the smart fan. For each fan, four temperature thresholds can be configured with corresponding fan power levels which are applied when the threshold is exceeded.

Also provide two different operations to control PWM speed:

  • SMART FAN Mode:

    please use EApiSmartFanSetMode function with SEMA_FAN_MODE_AUTO parameter and provides 4 levels of temperature & 4 levels of PWM are configured to get the below ladder chart:

    Take an example as the following table:

Level 1 Level 2 Level 3 level 4
Temperature 30℃ (t1) 40℃ (t2) 50℃ (t3) 80℃ (t4)
PWM 40 (p1) 50 (p2) 60 (p3) 100 (p4)

​ image-20200215141241146

  • SOFT FAN Mode:

    Please use BMC capability command to check Bit 34 & Bit 39 to see which design of SOFT FAN are using on your platform.

Bit 34 Bit 39 FAN Mode Type
0 1 SEMA_FAN_MODE_SOFT_FAN 4 level of temperature & PWM as the below linear chart 1
1 0 SEMA_FAN_MODE_AUTO 2 level of temperature & PWM as the below linear chart 2
0 0 Not support Not support
1 1 Not support Not support

  1. Linear chart 1 with 4 level of temperature & PWM configuration:

    Take an example as the following table:

Level 1 Level 2 Level 3 level 4
Temperature 30℃ (t1) 40℃ (t2) 50℃ (t3) 80℃ (t4)
PWM 40 (p1) 50 (p2) 60 (p3) 100 (p4)

image-20200120180638356

  1. Linear chart 2 with 2 level of temperature & PWM configuration:

​ For example: (The Rule is t1 = t2; t3 = t4; p3 = p4)

Level 1 Level 2 Level 3 level 4
Temperature 30℃ (t1) 30℃ (t2) 75℃ (t3) 75℃ (t4)
PWM 0 (p1) 30 (p2) 100 (p3) 100 (p4)

image-20200215144606569


sysfs Interface

Based on platform (LEC-AL, cExpress-WL, etc) device name (hwmonX) will change. To confirm the device name which is created by our driver, check the /sys/bus/platform/devices/adl-bmc-fan/hwmon/ path.

Ex: $ ls /sys/bus/platform/devices/adl-bmc-fan/hwmon/

Output: hwmon2

In the above example our device is hwmon2, so need to replace hwmonX in below commands with hwmon2

  • To set temperature set points (1-4) 

    echo {temperature} > /sys/class/hwmon/hwmonX/device/pwm_auto_point_temp

    In the example below, the user is setting temperature of set point 1 and Fan ID as 1 (SEMA_EAPI_ID_FAN_CPU) with temperature as 10

    echo 10 > /sys/class/hwmon/hwmon2/device/pwm1_auto_point1_temp

    echo 20 > /sys/class/hwmon/hwmon2/device/pwm1_auto_point2_temp

    echo 30 > /sys/class/hwmon/hwmon2/device/pwm1_auto_point3_temp

    echo 40 > /sys/class/hwmon/hwmon2/device/pwm1_auto_point4_temp

  • To get temperature set points (1-4)

    cat /sys/class/hwmon/hwmonX/device/pwm_auto_point_temp

    In the example below, the user is getting temperature of set point 1 and fan ID 1 (SEMA_EAPI_ID_FAN_CPU)

    cat /sys/class/hwmon/hwmon2/device/pwm1_auto_point1_temp

    cat /sys/class/hwmon/hwmon2/device/pwm1_auto_point2_temp

    cat /sys/class/hwmon/hwmon2/device/pwm1_auto_point3_temp

    cat /sys/class/hwmon/hwmon2/device/pwm1_auto_point4_temp

  • To set PWM set points (1-4)

    echo {PWM value} > /sys/class/hwmon/hwmonX/device/pwm_auto_point_pwm

    In the example below, user is setting PWM value of set point 1 and fan ID 1 (SEMA_EAPI_ID_FAN_CPU) with PWM level as 10

    echo 10 > /sys/class/hwmon/hwmon2/device/pwm1_auto_point1_pwm

    echo 10 > /sys/class/hwmon/hwmon2/device/pwm1_auto_point2_pwm

    echo 10 > /sys/class/hwmon/hwmon2/device/pwm1_auto_point3_pwm

    echo 10 > /sys/class/hwmon/hwmon2/device/pwm1_auto_point4_pwm

  • To get PWM set points (1-4)

    cat /sys/class/hwmon/hwmonX/device/pwm_auto_point_pwm

    In the example below, user is getting PWM value of set point 2 and fan ID as 2 (SEMA_EAPI_ID_FAN_SYSTEM_1 )

    cat /sys/class/hwmon/hwmon2/device/pwm2_auto_point1_pwm

    cat /sys/class/hwmon/hwmon2/device/pwm2_auto_point2_pwm

    cat /sys/class/hwmon/hwmon2/device/pwm2_auto_point3_pwm

    cat /sys/class/hwmon/hwmon2/device/pwm2_auto_point4_pwm

  • The configuration of Fan Mode:
Fan Mode Value
SEMA_FAN_AUTO 0
SEMA_FAN_OFF 1
SEMA_FAN_ON 2
SEMA_FAN_AUTO_SOFT_FAN 3

  • To set fan mode

    echo {FAN Mode value} > /sys/class/hwmon/hwmonX/device/pwm1_enable

    In the example below, user is setting fan mode as 1

    echo 1 > /sys/class/hwmon/hwmon2/device/pwm1_enable

  • To get fan mode

    cat /sys/class/hwmon/hwmon2/device/pwm1_enable
  • The configuration of temperature source
Temperature sources Value
CPU Temperature 0
Board Temperature 1

  • To set temperature source

    echo {temperature source value} /sys/class/hwmon/hwmonX/device/pwm1_auto_channels_temp

    In the example below, user is setting temperature source as 1 (Board temperature)

    echo 1 > /sys/class/hwmon/hwmon2/device/pwm1_auto_channels_temp

  • To get temperature source: 
    cat /sys/class/hwmon/hwmon2/device/pwm1_auto_channels_temp

  • To get CPU current temperature

    cat /sys/class/hwmon/hwmonX/device/cpu_cur_temp

  • To get CPU minimum temperature

    cat /sys/class/hwmon/hwmonX/device/cpu_min_temp
  • To get CPU maximum temperature 
    cat /sys/class/hwmon/hwmonX/device/cpu_max_temp
  • To get CPU startup temperature 
    cat /sys/class/hwmon/hwmonX/device/cpu_startup_temp
  • To get system1 current temperature 
    cat /sys/class/hwmon/hwmonX/device/sys1_cur_temp

  • To get system1 minimum temperature

    cat /sys/class/hwmon/hwmonX/device/sys1_min_temp

  • To get system1 maximum temperature

    cat /sys/class/hwmon/hwmonX/device/sys1_max_temp

  • To get system1 startup temperature.

    cat /sys/class/hwmon/hwmonX/device/sys1_startup_temp

  • To get system2 current temperature

    cat /sys/class/hwmon/hwmonX/device/sys2_cur_temp

  • To get system2 minimum temperature.

    cat /sys/class/hwmon/hwmonX/device/sys2_min_temp

  • To get system2 maximum temperature.

    cat /sys/class/hwmon/hwmonX/device/sys2_max_temp

  • To get system2 startup temperature.

    cat /sys/class/hwmon/hwmonX/device/sys2_startup_temp

  • To get CPU fan speed.

    cat /sys/class/hwmon/hwmonX/device/cpu_fan_speed

  • To get system1 fan speed.

    cat /sys/class/hwmon/hwmonX/device/sys1_fan_speed

  • To get system2 fan speed.

    cat /sys/class/hwmon/hwmonX/device/sys2_fan_speed

  • To get system3 fan speed.

    cat /sys/class/hwmon/hwmonX/device/sys3_fan_speed


SEMA EAPI (Both Windows & Linux supported)

uint32_t uint32_t EApiSmartFanSetTempSetpoints(
        uint32_t FanID, 
        uint32_t Level1, 
        uint32_t Level2,
        uint32_t Level3,
        uint32_t Level4
)

Description

Set temperature levels ( variable type is signed integer / Degree Celsius)

Parameters:

  • uint32_t FanID:

    Select FAN ID as the parameter

ID Description
SEMA_EAPI_ID_FAN_CPU CPU Fan
SEMA_EAPI_ID_FAN_SYSTEM_1 System Fan #1
SEMA_EAPI_ID_FAN_SYSTEM_2 System Fan #2
SEMA_EAPI_ID_FAN_SYSTEM_3 System Fan #3

  • uint32_t Level1:

    ​ Configure the first level of temperature (t1)

  • uint32_t Level2:

    ​ Configure the second level of temperature (t2)

  • uint32_t Level3:

    ​ Configure the third level of temperature (t3)

  • uint32_t Level4:

    ​ Configure the fourth level of temperature (t4)


uint32_t uint32_t EApiSmartFanGetTempSetpoints(uint32_t FanId, uint32_t* pLevel1, uint32_t* pLevel2, uint32_t* pLevel3, uint32_t* pLevel4)

Description

Get temperature levels

Parameters:

  • uint32_t FanID:

    Select FAN ID as the parameter

ID Description
SEMA_EAPI_ID_FAN_CPU CPU Fan
SEMA_EAPI_ID_FAN_SYSTEM_1 System Fan #1
SEMA_EAPI_ID_FAN_SYSTEM_2 System Fan #2
SEMA_EAPI_ID_FAN_SYSTEM_3 System Fan #3

  • uint32_t* Level1:

    ​ Pointer to a buffer that receives the current temperature level (t1)

  • uint32_t* Level2:

    ​ Pointer to a buffer that receives the current temperature level (t2)

  • uint32_t* Level3:

    ​ Pointer to a buffer that receives the current temperature level (t3)

  • uint32_t* Level4:

    ​ Pointer to a buffer that receives the current temperature level (t4)


uint32_t uint32_t EApiSmartFanSetPWMSetpoints(
        uint32_t FanID, 
        uint32_t Level1, 
        uint32_t Level2, 
        uint32_t Level3,
        uint32_t Level4
)

Description

Set PWM levels ( Range is 0 ~100 )

Parameters:

  • uint32_t FanID:

    Select FAN ID as the parameter

ID Description
SEMA_EAPI_ID_FAN_CPU CPU Fan
SEMA_EAPI_ID_FAN_SYSTEM_1 System Fan #1
SEMA_EAPI_ID_FAN_SYSTEM_2 System Fan #2
SEMA_EAPI_ID_FAN_SYSTEM_3 System Fan #3

  • uint32_t Level1:

    ​ Configure the first level of PWM (p1)

  • uint32_t Level2:

    ​ Configure the second level of PWM (p2)

  • uint32_t Level3:

    ​ Configure the third level of PWM (p3)

  • uint32_t Level4:

    ​ Configure the fourth level of PWM (p4)


uint32_t uint32_t EApiSmartFanGetTempSetpoints(
        uint32_t FanId, 
        uint32_t* pLevel1, 
        uint32_t* pLevel2, 
        uint32_t* pLevel3, 
        uint32_t* pLevel4
)

Description

Get PWM levels ( Range is 0 ~100 )

Parameters:

  • uint32_t FanID:

    Select FAN ID as the parameter

ID Description
SEMA_EAPI_ID_FAN_CPU CPU Fan
SEMA_EAPI_ID_FAN_SYSTEM_1 System Fan #1
SEMA_EAPI_ID_FAN_SYSTEM_2 System Fan #2
SEMA_EAPI_ID_FAN_SYSTEM_3 System Fan #3

  • uint32_t* Level1:

    ​ Pointer to a buffer that receives the current PWM level (p1)

  • uint32_t* Level2:

    ​ Pointer to a buffer that receives the current PWM level (p2)

  • uint32_t* Level3:

    ​ Pointer to a buffer that receives the current PWM level (p3)

  • uint32_t* Level4:

    ​ Pointer to a buffer that receives the current PWM level (p4)


uint32_t uint32_t EApiSmartFanSetMode(uint32_t FanId, uint8_t pFanMode)

Description

Set FAN Mode

Parameters:

  • uint32_t FanID:

    Select FAN ID as the parameter

ID Description
SEMA_EAPI_ID_FAN_CPU CPU Fan
SEMA_EAPI_ID_FAN_SYSTEM_1 System Fan #1
SEMA_EAPI_ID_FAN_SYSTEM_2 System Fan #2
SEMA_EAPI_ID_FAN_SYSTEM_3 System Fan #3

  • uint32_t pFanMode:

    Select FAN mode as the parameter

FAN Mode Description
SEMA_FAN_MODE_ON Default speed is only refer to PWM level #4
SEMA_FAN_MODE_OFF Turn Off FAN
SEMA_FAN_MODE_AUTO it will be configured as “stepwise operation between Temperature and PWM”
SEMA_FAN_MODE_SOFT_FAN it will be configured as “Linear operation between Temperature and PWM” 


uint32_t uint32_t EApiSmartFanGetMode(uint32_t FanId, uint8_t* pFanMode)

Description

Get FAN Mode

Parameters:

  • uint32_t FanID:

    Select FAN ID as the parameter

ID Description
SEMA_EAPI_ID_FAN_CPU CPU Fan
SEMA_EAPI_ID_FAN_SYSTEM_1 System Fan #1
SEMA_EAPI_ID_FAN_SYSTEM_2 System Fan #2
SEMA_EAPI_ID_FAN_SYSTEM_3 System Fan #3

  • uint8_t* pFanMode:

    Pointer to a buffer that receives the current FAN mode

FAN Mode Description
SEMA_FAN_MODE_ON Default speed is only refer to PWM level #4
SEMA_FAN_MODE_OFF Turn Off FAN
SEMA_FAN_MODE_AUTO it will be configured as “stepwise operation”
SEMA_FAN_MODE_SOFT_FAN it will be configured as “Linear operation” 


uint32_t uint32_t EApiSmartFanGetTempSrc(uint32_t FanId, uint8_t* pTempSrc)

Description

Get the temperature source for the specified FAN ID. SMART FAN will be triggered by the temperature source. Only CPU and system temperature could be set as temperature source of FANs

Parameters:

  • uint32_t FanID:

    Select FAN ID as the parameter

ID Description
SEMA_EAPI_ID_FAN_CPU CPU Fan
SEMA_EAPI_ID_FAN_SYSTEM_1 System Fan #1
SEMA_EAPI_ID_FAN_SYSTEM_2 System Fan #2
SEMA_EAPI_ID_FAN_SYSTEM_3 System Fan #3

  • uint8_t* pTempSrc:

    Pointer to a buffer that receives the current temperature source.

Temperature Source ID Description
SEMA_FAN_TEMP_CPU Temperature source from CPU
SEMA_FAN_TEMP_SYS Temperature source from System 


uint32_t uint32_t EApiSmartFanSetTempSrc(uint32_t FanId, uint8_t pTempSrc)

Description

Set the temperature source for the specified FAN ID. SMART FAN will be triggered by the temperature source. Only CPU and system temperature could be set as temperature source of FANs

Parameters:

  • uint32_t FanID:

    Select FAN ID as the parameter

ID Description
SEMA_EAPI_ID_FAN_CPU CPU Fan
SEMA_EAPI_ID_FAN_SYSTEM_1 System Fan #1
SEMA_EAPI_ID_FAN_SYSTEM_2 System Fan #2
SEMA_EAPI_ID_FAN_SYSTEM_3 System Fan #3

  • uint8_t pTempSrc:

    Select ID as the parameter

Temperature Source ID Description
SEMA_FAN_TEMP_CPU Temperature source from CPU
SEMA_FAN_TEMP_SYS Temperature source from System