Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/Documentation/hwmon/pwm-fan.rst b/Documentation/hwmon/pwm-fan.rst
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+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.
+=============== ======= =======================================================