xref: /openbmc/linux/Documentation/hwmon/tc654.rst (revision 7ebd8b66)
17ebd8b66SMauro Carvalho ChehabKernel driver tc654
27ebd8b66SMauro Carvalho Chehab===================
37ebd8b66SMauro Carvalho Chehab
47ebd8b66SMauro Carvalho ChehabSupported chips:
57ebd8b66SMauro Carvalho Chehab
67ebd8b66SMauro Carvalho Chehab  * Microchip TC654 and TC655
77ebd8b66SMauro Carvalho Chehab
87ebd8b66SMauro Carvalho Chehab    Prefix: 'tc654'
97ebd8b66SMauro Carvalho Chehab    Datasheet: http://ww1.m
107ebd8b66SMauro Carvalho Chehab    icrochip.com/downloads/en/DeviceDoc/20001734C.pdf
117ebd8b66SMauro Carvalho Chehab
127ebd8b66SMauro Carvalho ChehabAuthors:
137ebd8b66SMauro Carvalho Chehab      - Chris Packham <chris.packham@alliedtelesis.co.nz>
147ebd8b66SMauro Carvalho Chehab      - Masahiko Iwamoto <iwamoto@allied-telesis.co.jp>
157ebd8b66SMauro Carvalho Chehab
167ebd8b66SMauro Carvalho ChehabDescription
177ebd8b66SMauro Carvalho Chehab-----------
187ebd8b66SMauro Carvalho ChehabThis driver implements support for the Microchip TC654 and TC655.
197ebd8b66SMauro Carvalho Chehab
207ebd8b66SMauro Carvalho ChehabThe TC654 uses the 2-wire interface compatible with the SMBUS 2.0
217ebd8b66SMauro Carvalho Chehabspecification. The TC654 has two (2) inputs for measuring fan RPM and
227ebd8b66SMauro Carvalho Chehabone (1) PWM output which can be used for fan control.
237ebd8b66SMauro Carvalho Chehab
247ebd8b66SMauro Carvalho ChehabConfiguration Notes
257ebd8b66SMauro Carvalho Chehab-------------------
267ebd8b66SMauro Carvalho ChehabOrdinarily the pwm1_mode ABI is used for controlling the pwm output
277ebd8b66SMauro Carvalho Chehabmode.  However, for this chip the output is always pwm, and the
287ebd8b66SMauro Carvalho Chehabpwm1_mode determines if the pwm output is controlled via the pwm1 value
297ebd8b66SMauro Carvalho Chehabor via the Vin analog input.
307ebd8b66SMauro Carvalho Chehab
317ebd8b66SMauro Carvalho Chehab
327ebd8b66SMauro Carvalho ChehabSetting pwm1_mode to 1 will cause the pwm output to be driven based on
337ebd8b66SMauro Carvalho Chehabthe pwm1 value. Setting pwm1_mode to 0 will cause the pwm output to be
347ebd8b66SMauro Carvalho Chehabdriven based on the Vin input.
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