> -----Original Message----- > From: [email protected] [mailto:linux-pm- > [email protected]] On Behalf Of Zhang Rui > Sent: Monday, March 25, 2013 11:41 AM > To: Eduardo Valentin > Cc: [email protected]; [email protected] > Subject: Re: [PATCH 1/2] thermal: introduce > thermal_zone_lookup_temperature helper function > > On Fri, 2013-03-22 at 17:13 -0400, Eduardo Valentin wrote: > > This patch adds a helper function to get temperature of > > a thermal zone, based on the zone type name. > > > > It will perform a zone name lookup and return the last > > sensor temperature reading. In case the zone is not found > > or if the required parameters are invalid, it will return > > the corresponding error code. > > > > Signed-off-by: Eduardo Valentin <[email protected]> > > --- > > drivers/thermal/thermal_sys.c | 32 > ++++++++++++++++++++++++++++++++ > > include/linux/thermal.h | 1 + > > 2 files changed, 33 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c > > index 5bd95d4..f0caa13 100644 > > --- a/drivers/thermal/thermal_sys.c > > +++ b/drivers/thermal/thermal_sys.c > > @@ -1790,6 +1790,38 @@ void thermal_zone_device_unregister(struct > thermal_zone_device *tz) > > } > > EXPORT_SYMBOL_GPL(thermal_zone_device_unregister); > > > > +/** > > + * thermal_lookup_temperature - search for a zone and returns its > temperature > > + * @name: thermal zone name to fetch the temperature > > + * @temperature: pointer to store the zone temperature, in case it is > found > > + * > > + * When the zone is found, updates @temperature and returns 0. > > + * > > + * Return: -EINVAL in case of wrong parameters, -ENODEV in case the > zone > > + * is not found and 0 when it is successfully found. > > + */ > > +int thermal_zone_lookup_temperature(const char *name, int > *temperature) > > +{ > > + struct thermal_zone_device *pos = NULL; > > + bool found = false; > > + > > + if (!name || !temperature) > > + return -EINVAL; > > + > > + mutex_lock(&thermal_list_lock); > > + list_for_each_entry(pos, &thermal_tz_list, node) > > + if (!strcmp(pos->type, name)) { > > + found = true; > > + break; > > + } > > + if (found) > > + *temperature = pos->last_temperature; > > + mutex_unlock(&thermal_list_lock); > > + > > + return found ? 0 : -ENODEV; > > +} > > +EXPORT_SYMBOL_GPL(thermal_zone_lookup_temperature); > > + > please do not use thermal zone type as the parameter because unique > thermal zone type string is not a hard rule.
Okay, agree with this. This is what I am implementing in my changes as well. > If this is really needed, I'd prefer two APIs instead > 1. struct thermal_zone_device * thermal_zone_get_zone_by_name(char > *name); > 2. int thermal_zone_get_temperature(struct thermal_zone_device *, int > *temperature); Why do we need this second API? If the driver has a 'tz' pointer, it can use tz->ops->get_temp to retrieve the temperature, right ? Thanks, Durga
