Re: [PATCHv3 1/3] thermal: introduce thermal_zone_get_zone_by_name helper function

[Zhang Rui <rui.zhang@intel.com>]

On Fri, 2013-04-05 at 08:32 -0400, Eduardo Valentin wrote:
> This patch adds a helper function to get a reference of
> a thermal zone, based on the zone type name.
> 
> It will perform a zone name lookup and return a reference
> to a thermal zone device that matches the name requested.
> In case the zone is not found or when several zones match
> same name or if the required parameters are invalid, it will return
> the corresponding error code (ERR_PTR).
> 
> Cc: Durgadoss R <durgadoss.r@intel.com>
> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>

refreshed the patch to modify drivers/thermal/thermal_core.c instead of
drivers/thermal/thermal_sys.c and applied to thermal -next.

thanks,
rui
> ---
>  drivers/thermal/thermal_sys.c |   38 ++++++++++++++++++++++++++++++++++++++
>  include/linux/thermal.h       |    1 +
>  2 files changed, 39 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
> index 5bd95d4..e9b636b 100644
> --- a/drivers/thermal/thermal_sys.c
> +++ b/drivers/thermal/thermal_sys.c
> @@ -1790,6 +1790,44 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
>  }
>  EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
>  
> +/**
> + * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
> + * @name: thermal zone name to fetch the temperature
> + *
> + * When only one zone is found with the passed name, returns a reference to it.
> + *
> + * Return: On success returns a reference to an unique thermal zone with
> + * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
> + * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
> + */
> +struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
> +{
> +	struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
> +	unsigned int found = 0;
> +
> +	if (!name)
> +		goto exit;
> +
> +	mutex_lock(&thermal_list_lock);
> +	list_for_each_entry(pos, &thermal_tz_list, node)
> +		if (!strnicmp(name, pos->type, THERMAL_NAME_LENGTH)) {
> +			found++;
> +			ref = pos;
> +		}
> +	mutex_unlock(&thermal_list_lock);
> +
> +	/* nothing has been found, thus an error code for it */
> +	if (found == 0)
> +		ref = ERR_PTR(-ENODEV);
> +	else if (found > 1)
> +	/* Success only when an unique zone is found */
> +		ref = ERR_PTR(-EEXIST);
> +
> +exit:
> +	return ref;
> +}
> +EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
> +
>  #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..0cf9eb5 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 *);
> +struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name);
>  
>  int thermal_zone_trend_get(struct thermal_zone_device *, int);
>  struct thermal_instance *thermal_instance_get(struct thermal_zone_device *,