Commit Graph

5 Commits

Author SHA1 Message Date
Justin Ledford 5b38279e1a hwmon: (max31790) add fanN_enable
The MAX31790 has a tach input enable bit in each fan's configuration
register. This is only enabled by the driver if RPM mode is selected,
but the driver doesn't provide a way to independently enable tachometer
input regardless of the regulator mode.

By adding the fanN_enable sysfs files, we can decouple the tach input
from the regulator mode. Also update the documentation.

Signed-off-by: Justin Ledford <justinledford@google.com>
Link: https://lore.kernel.org/r/20220829195930.2521755-1-justinledford@google.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2022-09-19 06:17:05 -07:00
Guenter Roeck 148c847c9e hwmon: (max31790) Fix pwmX_enable attributes
pwmX_enable supports three possible values:

0: Fan control disabled. Duty cycle is fixed to 0%
1: Fan control enabled, pwm mode. Duty cycle is determined by
   values written into Target Duty Cycle registers.
2: Fan control enabled, rpm mode
   Duty cycle is adjusted such that fan speed matches
   the values in Target Count registers

The current code does not do this; instead, it mixes pwm control
configuration with fan speed monitoring configuration. Worse, it
reports that pwm control would be disabled (pwmX_enable==0) when
it is in fact enabled in pwm mode. Part of the problem may be that
the chip sets the "TACH input enable" bit on its own whenever the
mode bit is set to RPM mode, but that doesn't mean that "TACH input
enable" accurately reflects the pwm mode.

Fix it up and only handle pwm control with the pwmX_enable attributes.
In the documentation, clarify that disabling pwm control (pwmX_enable=0)
sets the pwm duty cycle to 0%. In the code, explain why TACH_INPUT_EN
is set together with RPM_MODE.

While at it, only update the configuration register if the configuration
has changed, and only update the cached configuration if updating the
chip configuration was successful.

Cc: Jan Kundrát <jan.kundrat@cesnet.cz>
Cc: Václav Kubernát <kubernat@cesnet.cz>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Václav Kubernát <kubernat@cesnet.cz>
Reviewed-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Link: https://lore.kernel.org/r/20210526154022.3223012-4-linux@roeck-us.net
2021-06-17 04:21:46 -07:00
Guenter Roeck 897f633989 hwmon: (max31790) Report correct current pwm duty cycles
The MAX31790 has two sets of registers for pwm duty cycles, one to request
a duty cycle and one to read the actual current duty cycle. Both do not
have to be the same.

When reporting the pwm duty cycle to the user, the actual pwm duty cycle
from pwm duty cycle registers needs to be reported. When setting it, the
pwm target duty cycle needs to be written. Since we don't know the actual
pwm duty cycle after a target pwm duty cycle has been written, set the
valid flag to false to indicate that actual pwm duty cycle should be read
from the chip instead of using cached values.

Cc: Jan Kundrát <jan.kundrat@cesnet.cz>
Cc: Václav Kubernát <kubernat@cesnet.cz>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Václav Kubernát <kubernat@ceesnet.cz>
Reviewed-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Link: https://lore.kernel.org/r/20210526154022.3223012-3-linux@roeck-us.net
2021-06-17 04:21:45 -07:00
Alexander A. Klimov ad736c1a4d hwmon: Replace HTTP links with HTTPS ones
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
	  If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
            If both the HTTP and HTTPS versions
            return 200 OK and serve the same content:
              Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200719175512.60745-1-grandmaster@al2klimov.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2020-07-24 07:44:57 -07:00
Mauro Carvalho Chehab 7ebd8b66dd docs: hwmon: Add an index file and rename docs to *.rst
Now that all files were converted to ReST format, rename them
and add an index.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2019-04-17 10:37:23 -07:00