ipv4: convert dst_metrics.refcnt from atomic_t to refcount_t

[mirror_ubuntu-artful-kernel.git] / Documentation / hwmon / tc654

Kernel driver tc654
===================

Supported chips:
  * Microchip TC654 and TC655
    Prefix: 'tc654'
    Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20001734C.pdf

Authors:
        Chris Packham <chris.packham@alliedtelesis.co.nz>
        Masahiko Iwamoto <iwamoto@allied-telesis.co.jp>

Description
-----------
This driver implements support for the Microchip TC654 and TC655.

The TC654 uses the 2-wire interface compatible with the SMBUS 2.0
specification. The TC654 has two (2) inputs for measuring fan RPM and
one (1) PWM output which can be used for fan control.

Configuration Notes
-------------------
Ordinarily the pwm1_mode ABI is used for controlling the pwm output
mode.  However, for this chip the output is always pwm, and the
pwm1_mode determines if the pwm output is controlled via the pwm1 value
or via the Vin analog input.


Setting pwm1_mode to 1 will cause the pwm output to be driven based on
the pwm1 value. Setting pwm1_mode to 0 will cause the pwm output to be
driven based on the Vin input.