mlxreg-fan.rst (2539B)
1Kernel driver mlxreg-fan 2======================== 3 4Provides FAN control for the next Mellanox systems: 5 6- QMB700, equipped with 40x200GbE InfiniBand ports; 7- MSN3700, equipped with 32x200GbE or 16x400GbE Ethernet ports; 8- MSN3410, equipped with 6x400GbE plus 48x50GbE Ethernet ports; 9- MSN3800, equipped with 64x1000GbE Ethernet ports; 10 11Author: Vadim Pasternak <vadimp@mellanox.com> 12 13These are the Top of the Rack systems, equipped with Mellanox switch 14board with Mellanox Quantum or Spectrume-2 devices. 15FAN controller is implemented by the programmable device logic. 16 17The default registers offsets set within the programmable device is as 18following: 19 20======================= ==== 21pwm1 0xe3 22fan1 (tacho1) 0xe4 23fan2 (tacho2) 0xe5 24fan3 (tacho3) 0xe6 25fan4 (tacho4) 0xe7 26fan5 (tacho5) 0xe8 27fan6 (tacho6) 0xe9 28fan7 (tacho7) 0xea 29fan8 (tacho8) 0xeb 30fan9 (tacho9) 0xec 31fan10 (tacho10) 0xed 32fan11 (tacho11) 0xee 33fan12 (tacho12) 0xef 34======================= ==== 35 36This setup can be re-programmed with other registers. 37 38Description 39----------- 40 41The driver implements a simple interface for driving a fan connected to 42a PWM output and tachometer inputs. 43This driver obtains PWM and tachometers registers location according to 44the system configuration and creates FAN/PWM hwmon objects and a cooling 45device. PWM and tachometers are sensed through the on-board programmable 46device, which exports its register map. This device could be attached to 47any bus type, for which register mapping is supported. 48Single instance is created with one PWM control, up to 12 tachometers and 49one cooling device. It could be as many instances as programmable device 50supports. 51The driver exposes the fan to the user space through the hwmon's and 52thermal's sysfs interfaces. 53 54/sys files in hwmon subsystem 55----------------------------- 56 57================= == =================================================== 58fan[1-12]_fault RO files for tachometers TACH1-TACH12 fault indication 59fan[1-12]_input RO files for tachometers TACH1-TACH12 input (in RPM) 60pwm1 RW file for fan[1-12] target duty cycle (0..255) 61================= == =================================================== 62 63/sys files in thermal subsystem 64------------------------------- 65 66================= == ==================================================== 67cur_state RW file for current cooling state of the cooling device 68 (0..max_state) 69max_state RO file for maximum cooling state of the cooling device 70================= == ====================================================