| Kernel driver mlxreg-fan |
| ======================== |
| |
| Provides FAN control for the next Mellanox systems: |
| |
| - QMB700, equipped with 40x200GbE InfiniBand ports; |
| - MSN3700, equipped with 32x200GbE or 16x400GbE Ethernet ports; |
| - MSN3410, equipped with 6x400GbE plus 48x50GbE Ethernet ports; |
| - MSN3800, equipped with 64x1000GbE Ethernet ports; |
| |
| Author: Vadim Pasternak <vadimp@mellanox.com> |
| |
| These are the Top of the Rack systems, equipped with Mellanox switch |
| board with Mellanox Quantum or Spectrume-2 devices. |
| FAN controller is implemented by the programmable device logic. |
| |
| The default registers offsets set within the programmable device is as |
| following: |
| |
| ======================= ==== |
| pwm1 0xe3 |
| fan1 (tacho1) 0xe4 |
| fan2 (tacho2) 0xe5 |
| fan3 (tacho3) 0xe6 |
| fan4 (tacho4) 0xe7 |
| fan5 (tacho5) 0xe8 |
| fan6 (tacho6) 0xe9 |
| fan7 (tacho7) 0xea |
| fan8 (tacho8) 0xeb |
| fan9 (tacho9) 0xec |
| fan10 (tacho10) 0xed |
| fan11 (tacho11) 0xee |
| fan12 (tacho12) 0xef |
| ======================= ==== |
| |
| This setup can be re-programmed with other registers. |
| |
| Description |
| ----------- |
| |
| The driver implements a simple interface for driving a fan connected to |
| a PWM output and tachometer inputs. |
| This driver obtains PWM and tachometers registers location according to |
| the system configuration and creates FAN/PWM hwmon objects and a cooling |
| device. PWM and tachometers are sensed through the on-board programmable |
| device, which exports its register map. This device could be attached to |
| any bus type, for which register mapping is supported. |
| Single instance is created with one PWM control, up to 12 tachometers and |
| one cooling device. It could be as many instances as programmable device |
| supports. |
| The driver exposes the fan to the user space through the hwmon's and |
| thermal's sysfs interfaces. |
| |
| /sys files in hwmon subsystem |
| ----------------------------- |
| |
| ================= == =================================================== |
| fan[1-12]_fault RO files for tachometers TACH1-TACH12 fault indication |
| fan[1-12]_input RO files for tachometers TACH1-TACH12 input (in RPM) |
| pwm1 RW file for fan[1-12] target duty cycle (0..255) |
| ================= == =================================================== |
| |
| /sys files in thermal subsystem |
| ------------------------------- |
| |
| ================= == ==================================================== |
| cur_state RW file for current cooling state of the cooling device |
| (0..max_state) |
| max_state RO file for maximum cooling state of the cooling device |
| ================= == ==================================================== |
