On 5/17/22 07:53, Uwe Kleine-König wrote:
Hello,
On Tue, May 17, 2022 at 04:26:20PM +0200, Alexander Stein wrote:
This adds the enable attribute which is used to differentiate if PWM duty
means to switch off regulator and PWM or to keep them enabled but
at inactive PWM output level.
Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
---
Documentation/hwmon/pwm-fan.rst | 10 ++++
drivers/hwmon/pwm-fan.c | 95 +++++++++++++++++++++++++++++----
2 files changed, 95 insertions(+), 10 deletions(-)
diff --git a/Documentation/hwmon/pwm-fan.rst b/Documentation/hwmon/pwm-fan.rst
index 82fe96742fee..0083480068d1 100644
--- a/Documentation/hwmon/pwm-fan.rst
+++ b/Documentation/hwmon/pwm-fan.rst
@@ -18,3 +18,13 @@ 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=switch off regulator and disable PWM
+ 1=keep regulator enabled and set PWM to inactive level
Is the pwm1_enable supposed to be set to 0 if that only does the right
thing if the PWM emits low after pwm_disable()? The question I raised in
v2 about "what is the meaning of disable?" hasn't evolved, has it?
I still think it's unfortunate, that "pwm1_enable" has an effect on the
regulator.
Trying to understand. Are you saying that you are ok with affecting the
regulator when setting pwm := 0 (even though that doesn't really mean
"disable pwm output"), but not with making the behavior explicit by
using pwm1_enable ?
Thanks,
Guenter
