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thermal: export thermal_zone_parameters to sysfs

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It's useful for tuning to be able to edit thermal_zone_parameters from
userspace.  Export them to the thermal_zone sysfs so that they can be
easily changed.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
This commit is contained in:
Javi Merino 2015-03-26 15:53:02 +00:00 committed by Eduardo Valentin
parent 0cdf97e1ad
commit 9f38271c6f
2 changed files with 153 additions and 0 deletions
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52
Documentation/thermal/sysfs-api.txt
View file

@ -184,6 +184,12 @@ Thermal zone device sys I/F, created once it's registered:
|---trip_point_[0-*]_type: Trip point type
|---trip_point_[0-*]_hyst: Hysteresis value for this trip point
|---emul_temp: Emulated temperature set node
|---sustainable_power: Sustainable dissipatable power
|---k_po: Proportional term during temperature overshoot
|---k_pu: Proportional term during temperature undershoot
|---k_i: PID's integral term in the power allocator gov
|---k_d: PID's derivative term in the power allocator
|---integral_cutoff: Offset above which errors are accumulated
Thermal cooling device sys I/F, created once it's registered:
/sys/class/thermal/cooling_device[0-*]:
@ -307,6 +313,52 @@ emul_temp
because userland can easily disable the thermal policy by simply
flooding this sysfs node with low temperature values.
sustainable_power
An estimate of the sustained power that can be dissipated by
the thermal zone. Used by the power allocator governor. For
more information see Documentation/thermal/power_allocator.txt
Unit: milliwatts
RW, Optional
k_po
The proportional term of the power allocator governor's PID
controller during temperature overshoot. Temperature overshoot
is when the current temperature is above the "desired
temperature" trip point. For more information see
Documentation/thermal/power_allocator.txt
RW, Optional
k_pu
The proportional term of the power allocator governor's PID
controller during temperature undershoot. Temperature undershoot
is when the current temperature is below the "desired
temperature" trip point. For more information see
Documentation/thermal/power_allocator.txt
RW, Optional
k_i
The integral term of the power allocator governor's PID
controller. This term allows the PID controller to compensate
for long term drift. For more information see
Documentation/thermal/power_allocator.txt
RW, Optional
k_d
The derivative term of the power allocator governor's PID
controller. For more information see
Documentation/thermal/power_allocator.txt
RW, Optional
integral_cutoff
Temperature offset from the desired temperature trip point
above which the integral term of the power allocator
governor's PID controller starts accumulating errors. For
example, if integral_cutoff is 0, then the integral term only
accumulates error when temperature is above the desired
temperature trip point. For more information see
Documentation/thermal/power_allocator.txt
RW, Optional
*****************************
* Cooling device attributes *
*****************************

101
drivers/thermal/thermal_core.c
View file

@ -875,6 +875,102 @@ emul_temp_store(struct device *dev, struct device_attribute *attr,
static DEVICE_ATTR(emul_temp, S_IWUSR, NULL, emul_temp_store);
#endif/*CONFIG_THERMAL_EMULATION*/
static ssize_t
sustainable_power_show(struct device *dev, struct device_attribute *devattr,
char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
if (tz->tzp)
return sprintf(buf, "%u\n", tz->tzp->sustainable_power);
else
return -EIO;
}
static ssize_t
sustainable_power_store(struct device *dev, struct device_attribute *devattr,
const char *buf, size_t count)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
u32 sustainable_power;
if (!tz->tzp)
return -EIO;
if (kstrtou32(buf, 10, &sustainable_power))
return -EINVAL;
tz->tzp->sustainable_power = sustainable_power;
return count;
}
static DEVICE_ATTR(sustainable_power, S_IWUSR | S_IRUGO, sustainable_power_show,
sustainable_power_store);
#define create_s32_tzp_attr(name) \
static ssize_t \
name##_show(struct device *dev, struct device_attribute *devattr, \
char *buf) \
{ \
struct thermal_zone_device *tz = to_thermal_zone(dev); \
\
if (tz->tzp) \
return sprintf(buf, "%u\n", tz->tzp->name); \
else \
return -EIO; \
} \
\
static ssize_t \
name##_store(struct device *dev, struct device_attribute *devattr, \
const char *buf, size_t count) \
{ \
struct thermal_zone_device *tz = to_thermal_zone(dev); \
s32 value; \
\
if (!tz->tzp) \
return -EIO; \
\
if (kstrtos32(buf, 10, &value)) \
return -EINVAL; \
\
tz->tzp->name = value; \
\
return count; \
} \
static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, name##_show, name##_store)
create_s32_tzp_attr(k_po);
create_s32_tzp_attr(k_pu);
create_s32_tzp_attr(k_i);
create_s32_tzp_attr(k_d);
create_s32_tzp_attr(integral_cutoff);
#undef create_s32_tzp_attr
static struct device_attribute *dev_tzp_attrs[] = {
&dev_attr_sustainable_power,
&dev_attr_k_po,
&dev_attr_k_pu,
&dev_attr_k_i,
&dev_attr_k_d,
&dev_attr_integral_cutoff,
};
static int create_tzp_attrs(struct device *dev)
{
int i;
for (i = 0; i < ARRAY_SIZE(dev_tzp_attrs); i++) {
int ret;
struct device_attribute *dev_attr = dev_tzp_attrs[i];
ret = device_create_file(dev, dev_attr);
if (ret)
return ret;
}
return 0;
}
/**
* power_actor_get_max_power() - get the maximum power that a cdev can consume
* @cdev: pointer to &thermal_cooling_device
@ -1712,6 +1808,11 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
if (result)
goto unregister;
/* Add thermal zone params */
result = create_tzp_attrs(&tz->device);
if (result)
goto unregister;
/* Update 'this' zone's governor information */
mutex_lock(&thermal_governor_lock);