v4.19.13 snapshot.
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+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;
+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.
+
+Author: Vadim Pasternak <vadimp@mellanox.com>
+
+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