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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
| commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
| tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /Documentation/hwmon/pwm-fan.rst | |
| parent | Initial commit. (diff) | |
| download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip | |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/hwmon/pwm-fan.rst')
| -rw-r--r-- | Documentation/hwmon/pwm-fan.rst | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/Documentation/hwmon/pwm-fan.rst b/Documentation/hwmon/pwm-fan.rst new file mode 100644 index 000000000..f77998b20 --- /dev/null +++ b/Documentation/hwmon/pwm-fan.rst @@ -0,0 +1,32 @@ +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. + +The driver provides the following sensor accesses in sysfs: + +=============== ======= ======================================================= +fan1_input ro fan tachometer speed in RPM +pwm1_enable rw keep enable mode, defines behaviour when pwm1=0 + 0 -> disable pwm and regulator + 1 -> enable pwm; if pwm==0, disable pwm, keep regulator enabled + 2 -> enable pwm; if pwm==0, keep pwm and regulator enabled + 3 -> enable pwm; if pwm==0, disable pwm and regulator +pwm1 rw relative speed (0-255), 255=max. speed. +=============== ======= ======================================================= |