[1/2] thermal: introduce thermal_zone_lookup_temperature helper function
diff mbox

Message ID 1363986787-28147-2-git-send-email-eduardo.valentin@ti.com
State Changes Requested
Delegated to: Zhang Rui
Headers show

Commit Message

Eduardo Valentin March 22, 2013, 9:13 p.m. UTC
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 <eduardo.valentin@ti.com>
---
 drivers/thermal/thermal_sys.c |   32 ++++++++++++++++++++++++++++++++
 include/linux/thermal.h       |    1 +
 2 files changed, 33 insertions(+), 0 deletions(-)

Comments

Zhang Rui March 25, 2013, 6:10 a.m. UTC | #1
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 <eduardo.valentin@ti.com>
> ---
>  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.
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);

And in thermal_zone_get_zone_by_name(), you should parse all the thermal
zone list and return an error code instead if multiple zones are found.

thanks,
rui
>  #ifdef CONFIG_NET
>  static struct genl_family thermal_event_genl_family = {
>  	.id = GENL_ID_GENERATE,
> diff --git a/include/linux/thermal.h b/include/linux/thermal.h
> index 542a39c..2b2f902 100644
> --- a/include/linux/thermal.h
> +++ b/include/linux/thermal.h
> @@ -237,6 +237,7 @@ void thermal_zone_device_update(struct thermal_zone_device *);
>  struct thermal_cooling_device *thermal_cooling_device_register(char *, void *,
>  		const struct thermal_cooling_device_ops *);
>  void thermal_cooling_device_unregister(struct thermal_cooling_device *);
> +int thermal_zone_lookup_temperature(const char *name, int *temperature);
>  
>  int thermal_zone_trend_get(struct thermal_zone_device *, int);
>  struct thermal_instance *thermal_instance_get(struct thermal_zone_device *,


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durgadoss.r@intel.com March 25, 2013, 6:20 a.m. UTC | #2
> -----Original Message-----

> From: linux-pm-owner@vger.kernel.org [mailto:linux-pm-

> owner@vger.kernel.org] On Behalf Of Zhang Rui

> Sent: Monday, March 25, 2013 11:41 AM

> To: Eduardo Valentin

> Cc: linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org

> 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 <eduardo.valentin@ti.com>

> > ---

> >  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
Zhang Rui March 25, 2013, 6:26 a.m. UTC | #3
On Mon, 2013-03-25 at 00:20 -0600, R, Durgadoss wrote:
> > -----Original Message-----
> > From: linux-pm-owner@vger.kernel.org [mailto:linux-pm-
> > owner@vger.kernel.org] On Behalf Of Zhang Rui
> > Sent: Monday, March 25, 2013 11:41 AM
> > To: Eduardo Valentin
> > Cc: linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org
> > 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 <eduardo.valentin@ti.com>
> > > ---
> > >  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 ?
> 

probably it is because one driver want to get the temperature of a
sensor registered by another driver.

thanks,
rui

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Eduardo Valentin March 25, 2013, 11:25 a.m. UTC | #4
On 25-03-2013 02:26, Zhang Rui wrote:
> On Mon, 2013-03-25 at 00:20 -0600, R, Durgadoss wrote:
>>> -----Original Message-----
>>> From: linux-pm-owner@vger.kernel.org [mailto:linux-pm-
>>> owner@vger.kernel.org] On Behalf Of Zhang Rui
>>> Sent: Monday, March 25, 2013 11:41 AM
>>> To: Eduardo Valentin
>>> Cc: linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org
>>> 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 <eduardo.valentin@ti.com>
>>>> ---
>>>>   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.

OK. I didn't consider this, as I was just resending the patch and the FW 
has evolve since last time I sent it.

>>
>> 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 ?
>>
>
> probably it is because one driver want to get the temperature of a
> sensor registered by another driver.

Unless API 1. can be used on other cases, why do we need two APIs? Why 
not keep the same signature I proposed, but with the same care on 'type' 
you mentioned for 1.?

>
> thanks,
> rui
>
>
>

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Patch
diff mbox

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);
+
 #ifdef CONFIG_NET
 static struct genl_family thermal_event_genl_family = {
 	.id = GENL_ID_GENERATE,
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 542a39c..2b2f902 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -237,6 +237,7 @@  void thermal_zone_device_update(struct thermal_zone_device *);
 struct thermal_cooling_device *thermal_cooling_device_register(char *, void *,
 		const struct thermal_cooling_device_ops *);
 void thermal_cooling_device_unregister(struct thermal_cooling_device *);
+int thermal_zone_lookup_temperature(const char *name, int *temperature);
 
 int thermal_zone_trend_get(struct thermal_zone_device *, int);
 struct thermal_instance *thermal_instance_get(struct thermal_zone_device *,