| Kernel driver pwm-fan | 
 | ===================== | 
 |  | 
 | This driver enables the use of a PWM module to drive a fan. It uses the | 
 | generic PWM interface thus it is hardware independent. It can be used on | 
 | many SoCs, as long as the SoC supplies a PWM line driver that exposes | 
 | the generic PWM API. | 
 |  | 
 | Author: Kamil Debski <k.debski@samsung.com> | 
 |  | 
 | Description | 
 | ----------- | 
 |  | 
 | The driver implements a simple interface for driving a fan connected to | 
 | a PWM output. It uses the generic PWM interface, thus it can be used with | 
 | a range of SoCs. The driver exposes the fan to the user space through | 
 | the hwmon's sysfs interface. | 
 |  | 
 | The fan rotation speed returned via the optional 'fan1_input' is extrapolated | 
 | from the sampled interrupts from the tachometer signal within 1 second. |