Implement locking in the hardware monitoring core for drivers using
the _with_info() API functions.
Most hardware monitoring drivers need to support locking to protect
against parallel accesses from userspace. With older API functions, such
locking had to be implemented in the driver code since sysfs attributes
were created by the driver. However, the _with_info() API creates sysfs
attributes in the hardware monitoring core. This makes it easy to move
the locking primitives into that code. This has the benefit of simplifying
driver code while at the same time reducing the risk of incomplete of bad
locking implementations in hardware monitoring drivers.
While this means that all accesses are forced to be synchronized, this
has little if any practical impact since accesses are expected to be low
frequency and are typically synchronized from userspace anyway since
only a single process is accessing the data. On top of that, many drivers
use regmap, which also has its own locking scheme and already serializes
accesses.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Many chips require 64-bit variables to display the accumulated energy,
even more so since the energy units are micro-Joule. Add new sensor type
"energy64" to support reporting the chip energy as 64-bit values.
Changing the entire hardware monitoring API is not feasible, and it is only
really necessary to support reading 64-bit values for the "energyX_input"
attribute. For this reason, keep the API as-is and use type casts on both
ends to pass 64-bit pointers when reading the accumulated energy. On the
write side (which is only useful for the energyX_enable attribute), keep
passing the written value as long.
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz> # INA780
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
A number of network PHY drivers use the following code:
name = devm_hwmon_sanitize_name(dev, dev_name(dev));
if (IS_ERR(name))
return PTR_ERR(name);
devm_hwmon_device_register_with_info(dev, name, ..);
Make this a generic fallback option and use the device name if no name
is provided to devm_hwmon_device_register_with_info(). This would allow
to simplify the affected drivers.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/1ebe6961-6445-4408-bfb4-b56173af9db5@gmail.com
[groeck: Update API document]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
devm_hwmon_device_unregister() has no in-tree user, and its implementation
is wrong since it does not pass the to-be-removed hardware monitoring
device as parameter. I do not envision a valid use for it; drivers needing
it should not have called devm_hwmon_device_register_with_info() in the
first place. Remove it.
Reported-by: Matthew Sanders <m@ttsande.rs>
Closes: https://lore.kernel.org/linux-hwmon/488b3bdf870ea76c4b943dbe5fd15ac8113019dc.camel@kernel.org/
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Remove description of deprecated registration functions from the hardware
monitoring kernel API documentation to help ensure that no attempts are
made to use them in new drivers.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
HWmon core receives an array of pointers to hwmon_channel_info and it
does not modify it, thus it can be array of const pointers for safety.
This allows drivers to make them also const.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Various attempts were made recently to "convert" the old
hwmon_device_register() API to devm_hwmon_device_register_with_info()
by just changing the function name without actually converting the
driver. Prevent this from happening by making the 'chip' parameter of
devm_hwmon_device_register_with_info() mandatory.
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>
