linux-toradex.git/Documentation/hwmon/abx500.rst, branch master Linux kernel for Apalis and Colibri modules hwmon: (abx500) Decomission abx500 driver 2021-01-28T01:44:18+00:00 Guenter Roeck linux@roeck-us.net 2020-12-21T18:59:33+00:00 d349626b42f5dbd08ffcb3f2c383b1f6f433b3c1 This deletes the ABx500 hwmon driver, the only supported variant being the AB8500. This driver has been replaced by generic frameworks. By inspecting the abx500 sysfs files we see that it contains things such as temp1_max, temp1_max_alarm, temp1_max_hyst, temp1_max_hyst_alarm, temp1_min, temp1_min_alarm. It becomes obvious that the abx500.c is a reimplementation of thermal zones. This is not very strange as the generic thermal zones were not invented when this driver was merged so people were rolling their own. The ab8500.c driver contains conversion tables for handling a thermistor on ADC channels AUX1 and AUX2. I managed to replace the functionality of the driver with: - Activation of the ntc_thermistor.c driver, CONFIG_SENSORS_NTC_THERMISTOR - Activation of thermal zones, CONFIG_THERMAL - In the device tree, connecting the NTC driver to the processed IIO channels from the AB8500 GPADC ADC forming two instances of NTC sensors. - Connecting the two NTC sensors to a "chassis" thermal zone in the device tree and setting that to hit the CPU frequency at 50 degrees celsius and do a critical shutdown at 70 degrees celsius, deploying a policy using the sensors. After talking to the original authors we concluded that the driver was never properly parameterized in production so what we now have in the device tree is already puts the thermistors to better use than what the hwmon driver did. The two remaining channels for two battery temperatures is already handled in the charging algorithms but can be optionally extended to thermal zones as well if we want these to trigger critical shutdown for the platform. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/20201221125521.768082-1-linus.walleij@linaro.org [groeck: Removed documentation and fixed up Makefile, Kconfig] Signed-off-by: Guenter Roeck <linux@roeck-us.net> 
This deletes the ABx500 hwmon driver, the only supported
variant being the AB8500.

This driver has been replaced by generic frameworks. By
inspecting the abx500 sysfs files we see that it contains
things such as temp1_max, temp1_max_alarm, temp1_max_hyst,
temp1_max_hyst_alarm, temp1_min, temp1_min_alarm.

It becomes obvious that the abx500.c is a reimplementation
of thermal zones. This is not very strange as the generic
thermal zones were not invented when this driver was merged
so people were rolling their own.

The ab8500.c driver contains conversion tables for handling
a thermistor on ADC channels AUX1 and AUX2.

I managed to replace the functionality of the driver with:

- Activation of the ntc_thermistor.c driver,
  CONFIG_SENSORS_NTC_THERMISTOR
- Activation of thermal zones, CONFIG_THERMAL
- In the device tree, connecting the NTC driver to the
  processed IIO channels from the AB8500 GPADC ADC forming
  two instances of NTC sensors.
- Connecting the two NTC sensors to a "chassis" thermal zone
  in the device tree and setting that to hit the CPU frequency
  at 50 degrees celsius and do a critical shutdown at 70
  degrees celsius, deploying a policy using the sensors.

After talking to the original authors we concluded that the
driver was never properly parameterized in production so
what we now have in the device tree is already puts the
thermistors to better use than what the hwmon driver did.

The two remaining channels for two battery temperatures is
already handled in the charging algorithms but can be
optionally extended to thermal zones as well if we want
these to trigger critical shutdown for the platform.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201221125521.768082-1-linus.walleij@linaro.org
[groeck: Removed documentation and fixed up Makefile, Kconfig]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
docs: hwmon: Add an index file and rename docs to *.rst 2019-04-17T17:37:23+00:00 Mauro Carvalho Chehab mchehab+samsung@kernel.org 2019-04-17T09:46:29+00:00 7ebd8b66dd9e5a0b65e5ee5e2b8e7ca382ec97b7 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> 
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>