Hi Everyone, The purpose of this patch series is to allow thermal zone creators to specify which properties (temperature or hysteresis) of which trip points can be set from user space via sysfs on a per-trip basis instead of passing writable trips masks to the thermal zone registration function which is both cumbersome and error prone and it doesn't even allow to request different treatment of different trip properties. The writable trip masks used today only affect trip temperatures (that is, if a trip point is in a writable trips mask, its temperature can be set via sysfs) and they only take effect if the CONFIG_THERMAL_WRITABLE_TRIPS kernel configuration option is set, which appears to be assumed by at least some of the drivers using writable trips masks. Some other drivers using them simply select CONFIG_THERMAL_WRITABLE_TRIPS which pretty much defeats its purpose (and imx even sets this option in its defconfig). For this reasons, patch [1/9] removes CONFIG_THERMAL_WRITABLE_TRIPS and makes the writable trips masks always work. Moreover, trip hysteresis, which is not affected either by the writable trips masks or by CONFIG_THERMAL_WRITABLE_TRIPS, can only be set via sysfs if the .set_trip_hyst() operation is provided by the given thermal zone, but currently this thermal zone operation is used by no one, so effectively trip hysteresis cannot be set via sysfs at all. This is not a problem for the majority of drivers that want trip temperatures to be set via sysfs, because they also don't want trip hysteresis to be changed for any trips (at least as far as I can say), but there are use cases in which it is desirable to be able to update trip hysteresis as well as trip temperature (for example see https://lore.kernel.org/linux-pm/20240106191502.29126-1-quic_manafm@xxxxxxxxxxx/). Those use cases are not addressed here directly, but after this series addressing them should be relatively straightforward. Namely, patch [2/9] adds flags to struct thermal_trip and defines two of them to indicate whether or not setting the temperature or hysteresis of the given trip via sysfs is allowed. If a writable trips mask is passed to thermal_zone_device_register_with_trips(), is it is used to set the "writable temperature" flag for the trips covered by it and that flag is then consulted by the thermal sysfs code. The "writable hysteresis" trip flag is also taken into account by the thermal sysfs code, but it is not set automatically in any case. Patch [3/9] is based on the observation that the .set_trip_hyst() thermal zone operation is never used - it simply drops that callback from struct thermal_zone_device_ops and adjusts the code checking its presence. Patches [4-8/9] update drivers using writable trips masks to set the new "writable temperature" flag directly instead and some of them are simplified a bit as a result. After these patches, all of the callers of thermal_zone_device_register_with_trips() pass a zero writable trips mask to it, so patch [9/9] drops that mask from the functions argument list and adjusts all of its callers accordingly. After all of the changes in this series, allowing the hysteresis value to be set via sysfs for a given trip is a matter of setting its "writable hysteresis" flag (and analogously for trip temperature). Thanks!
