| Vadim Pasternak | 65afb4c | 2018-07-03 07:00:09 +0000 | [diff] [blame^] | 1 | Kernel driver mlxreg-fan |
| 2 | ======================== |
| 3 | |
| 4 | Provides FAN control for the next Mellanox systems: |
| 5 | QMB700, equipped with 40x200GbE InfiniBand ports; |
| 6 | MSN3700, equipped with 32x200GbE or 16x400GbE Ethernet ports; |
| 7 | MSN3410, equipped with 6x400GbE plus 48x50GbE Ethernet ports; |
| 8 | MSN3800, equipped with 64x1000GbE Ethernet ports; |
| 9 | These are the Top of the Rack systems, equipped with Mellanox switch |
| 10 | board with Mellanox Quantum or Spectrume-2 devices. |
| 11 | FAN controller is implemented by the programmable device logic. |
| 12 | |
| 13 | The default registers offsets set within the programmable device is as |
| 14 | following: |
| 15 | - pwm1 0xe3 |
| 16 | - fan1 (tacho1) 0xe4 |
| 17 | - fan2 (tacho2) 0xe5 |
| 18 | - fan3 (tacho3) 0xe6 |
| 19 | - fan4 (tacho4) 0xe7 |
| 20 | - fan5 (tacho5) 0xe8 |
| 21 | - fan6 (tacho6) 0xe9 |
| 22 | - fan7 (tacho7) 0xea |
| 23 | - fan8 (tacho8) 0xeb |
| 24 | - fan9 (tacho9) 0xec |
| 25 | - fan10 (tacho10) 0xed |
| 26 | - fan11 (tacho11) 0xee |
| 27 | - fan12 (tacho12) 0xef |
| 28 | This setup can be re-programmed with other registers. |
| 29 | |
| 30 | Author: Vadim Pasternak <vadimp@mellanox.com> |
| 31 | |
| 32 | Description |
| 33 | ----------- |
| 34 | |
| 35 | The driver implements a simple interface for driving a fan connected to |
| 36 | a PWM output and tachometer inputs. |
| 37 | This driver obtains PWM and tachometers registers location according to |
| 38 | the system configuration and creates FAN/PWM hwmon objects and a cooling |
| 39 | device. PWM and tachometers are sensed through the on-board programmable |
| 40 | device, which exports its register map. This device could be attached to |
| 41 | any bus type, for which register mapping is supported. |
| 42 | Single instance is created with one PWM control, up to 12 tachometers and |
| 43 | one cooling device. It could be as many instances as programmable device |
| 44 | supports. |
| 45 | The driver exposes the fan to the user space through the hwmon's and |
| 46 | thermal's sysfs interfaces. |
| 47 | |
| 48 | /sys files in hwmon subsystem |
| 49 | ----------------------------- |
| 50 | |
| 51 | fan[1-12]_fault - RO files for tachometers TACH1-TACH12 fault indication |
| 52 | fan[1-12]_input - RO files for tachometers TACH1-TACH12 input (in RPM) |
| 53 | pwm1 - RW file for fan[1-12] target duty cycle (0..255) |
| 54 | |
| 55 | /sys files in thermal subsystem |
| 56 | ------------------------------- |
| 57 | |
| 58 | cur_state - RW file for current cooling state of the cooling device |
| 59 | (0..max_state) |
| 60 | max_state - RO file for maximum cooling state of the cooling device |