Re: [PATCH v3] thermal: add available policies sysfs attribute

[Wei Ni <wni@nvidia.com>]

Hi, Rui
Will you take this patch?

Thanks.
Wei.

On 2015年07月14日 15:40, Wei Ni wrote:
> The Linux thermal framework support to change thermal governor
> policy in userspace, but it can't show what available policies
> supported.
> 
> This patch adds available_policies attribute to the thermal
> framework, it can list the thermal governors which can be
> used for a particular zone. This attribute is read only.
> 
> Signed-off-by: Wei Ni <wni@nvidia.com>
> Reviewed-by: Javi Merino <javi.merino@arm.com>
> ---
> v3: Initialize "size" as PAGE_SIZE.
> v2: This change had been submitted and discussed in
> http://marc.info/?l=linux-tegra&m=138961183931457&w=2
> https://www.marc.info/?l=linux-pm&m=138986468007449&w=1
> cherry-picked it,and updated to this v2 version.
> 
>  Documentation/thermal/sysfs-api.txt |  6 ++++++
>  drivers/thermal/thermal_core.c      | 28 ++++++++++++++++++++++++++++
>  2 files changed, 34 insertions(+)
> 
> diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
> index c1f6864a8c5d..10f062ea6bc2 100644
> --- a/Documentation/thermal/sysfs-api.txt
> +++ b/Documentation/thermal/sysfs-api.txt
> @@ -180,6 +180,7 @@ Thermal zone device sys I/F, created once it's registered:
>      |---temp:			Current temperature
>      |---mode:			Working mode of the thermal zone
>      |---policy:			Thermal governor used for this zone
> +    |---available_policies:	Available thermal governors for this zone
>      |---trip_point_[0-*]_temp:	Trip point temperature
>      |---trip_point_[0-*]_type:	Trip point type
>      |---trip_point_[0-*]_hyst:	Hysteresis value for this trip point
> @@ -256,6 +257,10 @@ policy
>  	One of the various thermal governors used for a particular zone.
>  	RW, Required
>  
> +available_policies
> +	Available thermal governors which can be used for a particular zone.
> +	RO, Required
> +
>  trip_point_[0-*]_temp
>  	The temperature above which trip point will be fired.
>  	Unit: millidegree Celsius
> @@ -417,6 +422,7 @@ method, the sys I/F structure will be built like this:
>      |---temp:			37000
>      |---mode:			enabled
>      |---policy:			step_wise
> +    |---available_policies:	step_wise fair_share
>      |---trip_point_0_temp:	100000
>      |---trip_point_0_type:	critical
>      |---trip_point_1_temp:	80000
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 04659bfb888b..c4700950e42e 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -847,6 +847,27 @@ policy_show(struct device *dev, struct device_attribute *devattr, char *buf)
>  	return sprintf(buf, "%s\n", tz->governor->name);
>  }
>  
> +static ssize_t
> +available_policies_show(struct device *dev, struct device_attribute *devattr,
> +			char *buf)
> +{
> +	struct thermal_governor *pos;
> +	ssize_t count = 0;
> +	ssize_t size = PAGE_SIZE;
> +
> +	mutex_lock(&thermal_governor_lock);
> +
> +	list_for_each_entry(pos, &thermal_governor_list, governor_list) {
> +		size = PAGE_SIZE - count;
> +		count += scnprintf(buf + count, size, "%s ", pos->name);
> +	}
> +	count += scnprintf(buf + count, size, "\n");
> +
> +	mutex_unlock(&thermal_governor_lock);
> +
> +	return count;
> +}
> +
>  #ifdef CONFIG_THERMAL_EMULATION
>  static ssize_t
>  emul_temp_store(struct device *dev, struct device_attribute *attr,
> @@ -1032,6 +1053,7 @@ static DEVICE_ATTR(temp, 0444, temp_show, NULL);
>  static DEVICE_ATTR(mode, 0644, mode_show, mode_store);
>  static DEVICE_ATTR(passive, S_IRUGO | S_IWUSR, passive_show, passive_store);
>  static DEVICE_ATTR(policy, S_IRUGO | S_IWUSR, policy_show, policy_store);
> +static DEVICE_ATTR(available_policies, S_IRUGO, available_policies_show, NULL);
>  
>  /* sys I/F for cooling device */
>  #define to_cooling_device(_dev)	\
> @@ -1817,6 +1839,11 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
>  	if (result)
>  		goto unregister;
>  
> +	/* Create available_policies attribute */
> +	result = device_create_file(&tz->device, &dev_attr_available_policies);
> +	if (result)
> +		goto unregister;
> +
>  	/* Update 'this' zone's governor information */
>  	mutex_lock(&thermal_governor_lock);
>  
> @@ -1917,6 +1944,7 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
>  	if (tz->ops->get_mode)
>  		device_remove_file(&tz->device, &dev_attr_mode);
>  	device_remove_file(&tz->device, &dev_attr_policy);
> +	device_remove_file(&tz->device, &dev_attr_available_policies);
>  	remove_trip_attrs(tz);
>  	thermal_set_governor(tz, NULL);
>  
> 
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