On Wed, Jun 22, 2016 at 11:15:19AM +0800, Zhang Rui wrote: > On 一, 2016-06-06 at 19:44 +0800, Caesar Wang wrote: > > From: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> > > > > This adds support for hardware-tracked trip points to the device tree > > thermal sensor framework. > > > > The framework supports an arbitrary number of trip points. Whenever > > the current temperature is updated, the trip points immediately > > below and above the current temperature are found. A .set_trips > > callback is then called with the temperatures. If there is no trip > > point above or below the current temperature, the passed trip > > temperature will be -INT_MAX or INT_MAX respectively. In this > > callback, > > the driver should program the hardware such that it is notified > > when either of these trip points are triggered. When a trip point > > is triggered, the driver should call `thermal_zone_device_update' > > for the respective thermal zone. This will cause the trip points > > to be updated again. > > > > If .set_trips is not implemented, the framework behaves as before. > > > > This patch is based on an earlier version from Mikko Perttunen > > <mikko.perttunen@xxxxxxxx> > > > > Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> > > Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx> > > Cc: Zhang Rui <rui.zhang@xxxxxxxxx> > > Cc: Eduardo Valentin <edubezval@xxxxxxxxx> > > Cc: linux-pm@xxxxxxxxxxxxxxx > > > > --- > > > > Changes in v5: > > - add the lock for thermal_zone_set_trips function. > > - change based on next kernel. > > > > Changes in v4: > > - Missing the lock added in v3. > > > > Changes in v3: > > - as Javi comments on https://patchwork.kernel.org/patch/9001281/. > > - add the lock for preventing the called from multi placce > > - add the note for pre_low/high_trip. > > > > Changes in v2: > > - update the sysfs-api.txt for set_trips. > > > > Documentation/thermal/sysfs-api.txt | 7 +++++ > > drivers/thermal/thermal_core.c | 54 > > +++++++++++++++++++++++++++++++++++++ > > drivers/thermal/thermal_sysfs.c | 3 +++ > > include/linux/thermal.h | 10 +++++++ > > 4 files changed, 74 insertions(+) > > > > diff --git a/Documentation/thermal/sysfs-api.txt > > b/Documentation/thermal/sysfs-api.txt > > index efc3f3d..75d8838 100644 > > --- a/Documentation/thermal/sysfs-api.txt > > +++ b/Documentation/thermal/sysfs-api.txt > > @@ -49,6 +49,9 @@ temperature) and throttle appropriate devices. > > .bind: bind the thermal zone device with a thermal cooling > > device. > > .unbind: unbind the thermal zone device with a thermal > > cooling device. > > .get_temp: get the current temperature of the thermal zone. > > + .set_trips: set the trip points window. Whenever the current > > temperature > > + is updated, the trip points immediately below > > and above the > > + current temperature are found. > > .get_mode: get the current mode (enabled/disabled) of the > > thermal zone. > > - "enabled" means the kernel thermal management is > > enabled. > > - "disabled" will prevent kernel thermal driver action > > upon trip points > > @@ -95,6 +98,10 @@ temperature) and throttle appropriate devices. > > get_temp: a pointer to a function > > that reads the > > sensor temperature. This is > > mandatory > > callback provided by sensor > > driver. > > + set_trips: a pointer to a function that > > sets a > > + temperature window. When > > this window is > > + left the driver must inform > > the thermal > > + core via > > thermal_zone_device_update. > > get_trend: a pointer to a function > > that reads the > > sensor temperature trend. > > set_emul_temp: a pointer to a > > function that sets > > diff --git a/drivers/thermal/thermal_core.c > > b/drivers/thermal/thermal_core.c > > index 792aab7..e69aee2 100644 > > --- a/drivers/thermal/thermal_core.c > > +++ b/drivers/thermal/thermal_core.c > > @@ -368,6 +368,56 @@ static void handle_thermal_trip(struct > > thermal_zone_device *tz, int trip) > > monitor_thermal_zone(tz); > > } > > > > +void thermal_zone_set_trips(struct thermal_zone_device *tz) > > +{ > > + int low = -INT_MAX; > > + int high = INT_MAX; > > + int trip_temp, hysteresis; > > + int i, ret; > > + > > + mutex_lock(&tz->lock); > > + > > + if (!tz->ops->set_trips) > > + goto exit; > > + > if (!tz->ops->get_trip_hyst) > goto exit; > > otherwise, the patch looks good to me. Agreed here, you need to check if get_trip_hyst is present before calling it. Not all drivers have it. Besides, I would prefer you to lock after the checks: if (!tz->ops->set_trips) return; if (!tz->ops->get_trip_hyst) return; mutex_lock(&tz->lock); > > thanks, > rui > > + for (i = 0; i < tz->trips; i++) { > > + int trip_low; > > + > > + tz->ops->get_trip_temp(tz, i, &trip_temp); > > + tz->ops->get_trip_hyst(tz, i, &hysteresis); > > + > > + trip_low = trip_temp - hysteresis; > > + > > + if (trip_low < tz->temperature && trip_low > low) > > + low = trip_low; > > + > > + if (trip_temp > tz->temperature && trip_temp < high) > > + high = trip_temp; > > + } > > + > > + /* No need to change trip points */ > > + if (tz->prev_low_trip == low && tz->prev_high_trip == high) > > + goto exit; > > + > > + tz->prev_low_trip = low; > > + tz->prev_high_trip = high; > > + > > + dev_dbg(&tz->device, "new temperature boundaries: %d < x < > > %d\n", > > + low, high); > > + > > + /* > > + * Set a temperature window. When this window is left the > > driver > > + * must inform the thermal core via > > thermal_zone_device_update. > > + */ > > + ret = tz->ops->set_trips(tz, low, high); > > + if (ret) > > + dev_err(&tz->device, "Failed to set trips: %d\n", > > ret); > > + > > +exit: > > + mutex_unlock(&tz->lock); > > +} > > +EXPORT_SYMBOL_GPL(thermal_zone_set_trips); > > + > > static void update_temperature(struct thermal_zone_device *tz) > > { > > int temp, ret; > > @@ -417,6 +467,8 @@ void thermal_zone_device_update(struct > > thermal_zone_device *tz) > > > > update_temperature(tz); > > > > + thermal_zone_set_trips(tz); > > + > > for (count = 0; count < tz->trips; count++) > > handle_thermal_trip(tz, count); > > } > > @@ -1175,6 +1227,8 @@ thermal_zone_device_register(const char *type, > > int trips, int mask, > > tz->trips = trips; > > tz->passive_delay = passive_delay; > > tz->polling_delay = polling_delay; > > + tz->prev_low_trip = INT_MAX; > > + tz->prev_high_trip = -INT_MAX; > > > > /* sys I/F */ > > /* Add nodes that are always present via .groups */ > > diff --git a/drivers/thermal/thermal_sysfs.c > > b/drivers/thermal/thermal_sysfs.c > > index 743df50..33bbe30 100644 > > --- a/drivers/thermal/thermal_sysfs.c > > +++ b/drivers/thermal/thermal_sysfs.c > > @@ -219,6 +219,9 @@ trip_point_hyst_store(struct device *dev, struct > > device_attribute *attr, > > ret = tz->ops->set_trip_hyst(tz, trip, temperature); > > mutex_unlock(&tz->lock); > > > > + if (!ret) > > + thermal_zone_set_trips(tz); > > + > > return ret ? ret : count; > > } > > > > diff --git a/include/linux/thermal.h b/include/linux/thermal.h > > index ea667b6..780e69d 100644 > > --- a/include/linux/thermal.h > > +++ b/include/linux/thermal.h > > @@ -99,6 +99,7 @@ struct thermal_zone_device_ops { > > int (*unbind) (struct thermal_zone_device *, > > struct thermal_cooling_device *); > > int (*get_temp) (struct thermal_zone_device *, int *); > > + int (*set_trips) (struct thermal_zone_device *, int, int); > > int (*get_mode) (struct thermal_zone_device *, > > enum thermal_device_mode *); > > int (*set_mode) (struct thermal_zone_device *, > > @@ -169,6 +170,10 @@ struct thermal_attr { > > * @last_temperature: previous temperature read > > * @emul_temperature: emulated temperature when using > > CONFIG_THERMAL_EMULATION > > * @passive: 1 if you've crossed a passive trip > > point, 0 otherwise. > > + * @prev_low_trip: the low current temperature if you've > > crossed a passive > > + trip point. > > + * @prev_high_trip: the above current temperature if you've > > crossed a > > + passive trip point. > > * @forced_passive: If > 0, temperature at which to switch on > > all ACPI > > * processor cooling devices. Currently only > > used by the > > * step-wise governor. > > @@ -201,6 +206,8 @@ struct thermal_zone_device { > > int last_temperature; > > int emul_temperature; > > int passive; > > + int prev_low_trip; > > + int prev_high_trip; > > unsigned int forced_passive; > > atomic_t need_update; > > struct thermal_zone_device_ops *ops; > > @@ -428,6 +435,7 @@ int thermal_zone_bind_cooling_device(struct > > thermal_zone_device *, int, > > int thermal_zone_unbind_cooling_device(struct thermal_zone_device *, > > int, > > struct thermal_cooling_device > > *); > > void thermal_zone_device_update(struct thermal_zone_device *); > > +void thermal_zone_set_trips(struct thermal_zone_device *); > > > > struct thermal_cooling_device *thermal_cooling_device_register(char > > *, void *, > > const struct thermal_cooling_device_ops *); > > @@ -477,6 +485,8 @@ static inline int > > thermal_zone_unbind_cooling_device( > > { return -ENODEV; } > > static inline void thermal_zone_device_update(struct > > thermal_zone_device *tz) > > { } > > +static inline void thermal_zone_set_trips(struct thermal_zone_device > > *tz) > > +{ } > > static inline struct thermal_cooling_device * > > thermal_cooling_device_register(char *type, void *devdata, > > const struct thermal_cooling_device_ops *ops) -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
