linux/drivers/thermal/thermal_helpers.c
Daniel Lezcano 17d399cd9c thermal/core: Precompute the delays from msecs to jiffies
The delays are stored in ms units and when the polling function is
called this delay is converted into jiffies at each call.

Instead of doing the conversion again and again, compute the jiffies
at init time and use the value directly when setting the polling.

Cc: Thara Gopinath <thara.gopinath@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Thara Gopinath <thara.gopinath@linaro.org>
Link: https://lore.kernel.org/r/20201216220337.839878-1-daniel.lezcano@linaro.org
2021-01-19 22:23:38 +01:00

255 lines
6.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* thermal_helpers.c - helper functions to handle thermal devices
*
* Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com>
*
* Highly based on original thermal_core.c
* Copyright (C) 2008 Intel Corp
* Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
* Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/device.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <trace/events/thermal.h>
#include "thermal_core.h"
int get_tz_trend(struct thermal_zone_device *tz, int trip)
{
enum thermal_trend trend;
if (tz->emul_temperature || !tz->ops->get_trend ||
tz->ops->get_trend(tz, trip, &trend)) {
if (tz->temperature > tz->last_temperature)
trend = THERMAL_TREND_RAISING;
else if (tz->temperature < tz->last_temperature)
trend = THERMAL_TREND_DROPPING;
else
trend = THERMAL_TREND_STABLE;
}
return trend;
}
EXPORT_SYMBOL(get_tz_trend);
struct thermal_instance *
get_thermal_instance(struct thermal_zone_device *tz,
struct thermal_cooling_device *cdev, int trip)
{
struct thermal_instance *pos = NULL;
struct thermal_instance *target_instance = NULL;
mutex_lock(&tz->lock);
mutex_lock(&cdev->lock);
list_for_each_entry(pos, &tz->thermal_instances, tz_node) {
if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
target_instance = pos;
break;
}
}
mutex_unlock(&cdev->lock);
mutex_unlock(&tz->lock);
return target_instance;
}
EXPORT_SYMBOL(get_thermal_instance);
/**
* thermal_zone_get_temp() - returns the temperature of a thermal zone
* @tz: a valid pointer to a struct thermal_zone_device
* @temp: a valid pointer to where to store the resulting temperature.
*
* When a valid thermal zone reference is passed, it will fetch its
* temperature and fill @temp.
*
* Return: On success returns 0, an error code otherwise
*/
int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
{
int ret = -EINVAL;
int count;
int crit_temp = INT_MAX;
enum thermal_trip_type type;
if (!tz || IS_ERR(tz) || !tz->ops->get_temp)
goto exit;
mutex_lock(&tz->lock);
ret = tz->ops->get_temp(tz, temp);
if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) {
for (count = 0; count < tz->trips; count++) {
ret = tz->ops->get_trip_type(tz, count, &type);
if (!ret && type == THERMAL_TRIP_CRITICAL) {
ret = tz->ops->get_trip_temp(tz, count,
&crit_temp);
break;
}
}
/*
* Only allow emulating a temperature when the real temperature
* is below the critical temperature so that the emulation code
* cannot hide critical conditions.
*/
if (!ret && *temp < crit_temp)
*temp = tz->emul_temperature;
}
mutex_unlock(&tz->lock);
exit:
return ret;
}
EXPORT_SYMBOL_GPL(thermal_zone_get_temp);
/**
* thermal_zone_set_trips - Computes the next trip points for the driver
* @tz: a pointer to a thermal zone device structure
*
* The function computes the next temperature boundaries by browsing
* the trip points. The result is the closer low and high trip points
* to the current temperature. These values are passed to the backend
* driver to let it set its own notification mechanism (usually an
* interrupt).
*
* It does not return a value
*/
void thermal_zone_set_trips(struct thermal_zone_device *tz)
{
int low = -INT_MAX;
int high = INT_MAX;
int trip_temp, hysteresis;
int i, ret;
mutex_lock(&tz->lock);
if (!tz->ops->set_trips || !tz->ops->get_trip_hyst)
goto exit;
for (i = 0; i < tz->trips; i++) {
int trip_low;
tz->ops->get_trip_temp(tz, i, &trip_temp);
tz->ops->get_trip_hyst(tz, i, &hysteresis);
trip_low = trip_temp - hysteresis;
if (trip_low < tz->temperature && trip_low > low)
low = trip_low;
if (trip_temp > tz->temperature && trip_temp < high)
high = trip_temp;
}
/* No need to change trip points */
if (tz->prev_low_trip == low && tz->prev_high_trip == high)
goto exit;
tz->prev_low_trip = low;
tz->prev_high_trip = high;
dev_dbg(&tz->device,
"new temperature boundaries: %d < x < %d\n", low, high);
/*
* Set a temperature window. When this window is left the driver
* must inform the thermal core via thermal_zone_device_update.
*/
ret = tz->ops->set_trips(tz, low, high);
if (ret)
dev_err(&tz->device, "Failed to set trips: %d\n", ret);
exit:
mutex_unlock(&tz->lock);
}
void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
{
*delay_jiffies = msecs_to_jiffies(delay_ms);
if (delay_ms > 1000)
*delay_jiffies = round_jiffies(*delay_jiffies);
}
static void thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev,
int target)
{
if (cdev->ops->set_cur_state(cdev, target))
return;
thermal_notify_cdev_state_update(cdev->id, target);
thermal_cooling_device_stats_update(cdev, target);
}
void thermal_cdev_update(struct thermal_cooling_device *cdev)
{
struct thermal_instance *instance;
unsigned long target = 0;
mutex_lock(&cdev->lock);
/* cooling device is updated*/
if (cdev->updated) {
mutex_unlock(&cdev->lock);
return;
}
/* Make sure cdev enters the deepest cooling state */
list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) {
dev_dbg(&cdev->device, "zone%d->target=%lu\n",
instance->tz->id, instance->target);
if (instance->target == THERMAL_NO_TARGET)
continue;
if (instance->target > target)
target = instance->target;
}
thermal_cdev_set_cur_state(cdev, target);
cdev->updated = true;
mutex_unlock(&cdev->lock);
trace_cdev_update(cdev, target);
dev_dbg(&cdev->device, "set to state %lu\n", target);
}
EXPORT_SYMBOL(thermal_cdev_update);
/**
* thermal_zone_get_slope - return the slope attribute of the thermal zone
* @tz: thermal zone device with the slope attribute
*
* Return: If the thermal zone device has a slope attribute, return it, else
* return 1.
*/
int thermal_zone_get_slope(struct thermal_zone_device *tz)
{
if (tz && tz->tzp)
return tz->tzp->slope;
return 1;
}
EXPORT_SYMBOL_GPL(thermal_zone_get_slope);
/**
* thermal_zone_get_offset - return the offset attribute of the thermal zone
* @tz: thermal zone device with the offset attribute
*
* Return: If the thermal zone device has a offset attribute, return it, else
* return 0.
*/
int thermal_zone_get_offset(struct thermal_zone_device *tz)
{
if (tz && tz->tzp)
return tz->tzp->offset;
return 0;
}
EXPORT_SYMBOL_GPL(thermal_zone_get_offset);