[PATCH linux v4 0/2] Support for ASPEED AST2400/AST2500 PWM and Fan Tach driver

Jaghathiswari Rankappagounder Natarajan jaghu at google.com
Sat Mar 11 12:53:49 AEDT 2017

Support for ASPEED AST2400/AST2500 PWM and Fan Tach driver.
Patches based on the upstream tag 4.9. Changes made in Version 4 are indicated
in the individual patches.
The AST2400/AST2500 PWM controller can support 8 PWM output ports.
The AST2400/AST2500 Fan Tach controller can support 16 tachometer inputs.
The hwmon driver provides sysfs entries through which the user can configure the
duty cycle for the particular PWM output port and read the fan rpm value for
the particular tachometer input.
Added devicetree binding documentation for AST2400/AST2500 PWM and Fan Tach

Tested on Zaius board (which has AST2500 chip) and observed that when
duty cycle is lowered then the fan speed is lowered and lower fan rpm value(
corresponding to the duty cycle) is reported and when the duty cycle is
increased then the fan speed increases and higher fan rpm value(corresponding
to the duty cycle) is reported.

Jaghathiswari Rankappagounder Natarajan (2):
  Documentation: dt-bindings: Document bindings for ASPEED
    AST2400/AST2500 PWM and Fan tach controller device driver
  drivers: hwmon: Support for ASPEED PWM/Fan tach

 .../devicetree/bindings/hwmon/aspeed-pwm-tacho.txt |  86 ++
 Documentation/hwmon/aspeed-pwm-tacho               |  22 +
 drivers/hwmon/Kconfig                              |   9 +
 drivers/hwmon/Makefile                             |   1 +
 drivers/hwmon/aspeed-pwm-tacho.c                   | 866 +++++++++++++++++++++
 5 files changed, 984 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt
 create mode 100644 Documentation/hwmon/aspeed-pwm-tacho
 create mode 100644 drivers/hwmon/aspeed-pwm-tacho.c


More information about the openbmc mailing list