// SPDX-License-Identifier: GPL-2.0
/*
* of-thermal.c - Generic Thermal Management device tree support.
*
* Copyright (C) 2013 Texas Instruments
* Copyright (C) 2013 Eduardo Valentin <[email protected]>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/err.h>
#include <linux/export.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/thermal.h>
#include <linux/types.h>
#include <linux/string.h>
#include "thermal_core.h"
/*** functions parsing device tree nodes ***/
/*
* It maps 'enum thermal_trip_type' found in include/linux/thermal.h
* into the device tree binding of 'trip', property type.
*/
static const char * const trip_types[] = {
[THERMAL_TRIP_ACTIVE] = "active",
[THERMAL_TRIP_PASSIVE] = "passive",
[THERMAL_TRIP_HOT] = "hot",
[THERMAL_TRIP_CRITICAL] = "critical",
};
/**
* thermal_of_get_trip_type - Get phy mode for given device_node
* @np: Pointer to the given device_node
* @type: Pointer to resulting trip type
*
* The function gets trip type string from property 'type',
* and store its index in trip_types table in @type,
*
* Return: 0 on success, or errno in error case.
*/
static int thermal_of_get_trip_type(struct device_node *np,
enum thermal_trip_type *type)
{
const char *t;
int err, i;
err = of_property_read_string(np, "type", &t);
if (err < 0)
return err;
for (i = 0; i < ARRAY_SIZE(trip_types); i++)
if (!strcasecmp(t, trip_types[i])) {
*type = i;
return 0;
}
return -ENODEV;
}
static int thermal_of_populate_trip(struct device_node *np,
struct thermal_trip *trip)
{
int prop;
int ret;
ret = of_property_read_u32(np, "temperature", &prop);
if (ret < 0) {
pr_err("missing temperature property\n");
return ret;
}
trip->temperature = prop;
ret = of_property_read_u32(np, "hysteresis", &prop);
if (ret < 0) {
pr_err("missing hysteresis property\n");
return ret;
}
trip->hysteresis = prop;
ret = thermal_of_get_trip_type(np, &trip->type);
if (ret < 0) {
pr_err("wrong trip type property\n");
return ret;
}
trip->flags = THERMAL_TRIP_FLAG_RW_TEMP;
trip->priv = np;
return 0;
}
static struct thermal_trip *thermal_of_trips_init(struct device_node *np, int *ntrips)
{
struct thermal_trip *tt;
struct device_node *trips;
int ret, count;
trips = of_get_child_by_name(np, "trips");
if (!trips) {
pr_err("Failed to find 'trips' node\n");
return ERR_PTR(-EINVAL);
}
count = of_get_child_count(trips);
if (!count) {
pr_err("No trip point defined\n");
ret = -EINVAL;
goto out_of_node_put;
}
tt = kzalloc(sizeof(*tt) * count, GFP_KERNEL);
if (!tt) {
ret = -ENOMEM;
goto out_of_node_put;
}
*ntrips = count;
count = 0;
for_each_child_of_node_scoped(trips, trip) {
ret = thermal_of_populate_trip(trip, &tt[count++]);
if (ret)
goto out_kfree;
}
of_node_put(trips);
return tt;
out_kfree:
kfree(tt);
*ntrips = 0;
out_of_node_put:
of_node_put(trips);
return ERR_PTR(ret);
}
static struct device_node *of_thermal_zone_find(struct device_node *sensor, int id)
{
struct device_node *np, *tz;
struct of_phandle_args sensor_specs;
np = of_find_node_by_name(NULL, "thermal-zones");
if (!np) {
pr_debug("No thermal zones description\n");
return ERR_PTR(-ENODEV);
}
/*
* Search for each thermal zone, a defined sensor
* corresponding to the one passed as parameter
*/
for_each_available_child_of_node_scoped(np, child) {
int count, i;
count = of_count_phandle_with_args(child, "thermal-sensors",
"#thermal-sensor-cells");
if (count <= 0) {
pr_err("%pOFn: missing thermal sensor\n", child);
tz = ERR_PTR(-EINVAL);
goto out;
}
for (i = 0; i < count; i++) {
int ret;
ret = of_parse_phandle_with_args(child, "thermal-sensors",
"#thermal-sensor-cells",
i, &sensor_specs);
if (ret < 0) {
pr_err("%pOFn: Failed to read thermal-sensors cells: %d\n", child, ret);
tz = ERR_PTR(ret);
goto out;
}
if ((sensor == sensor_specs.np) && id == (sensor_specs.args_count ?
sensor_specs.args[0] : 0)) {
pr_debug("sensor %pOFn id=%d belongs to %pOFn\n", sensor, id, child);
tz = no_free_ptr(child);
goto out;
}
}
}
tz = ERR_PTR(-ENODEV);
out:
of_node_put(np);
return tz;
}
static int thermal_of_monitor_init(struct device_node *np, int *delay, int *pdelay)
{
int ret;
ret = of_property_read_u32(np, "polling-delay-passive", pdelay);
if (ret == -EINVAL) {
*pdelay = 0;
} else if (ret < 0) {
pr_err("%pOFn: Couldn't get polling-delay-passive: %d\n", np, ret);
return ret;
}
ret = of_property_read_u32(np, "polling-delay", delay);
if (ret == -EINVAL) {
*delay = 0;
} else if (ret < 0) {
pr_err("%pOFn: Couldn't get polling-delay: %d\n", np, ret);
return ret;
}
return 0;
}
static void thermal_of_parameters_init(struct device_node *np,
struct thermal_zone_params *tzp)
{
int coef[2];
int ncoef = ARRAY_SIZE(coef);
int prop, ret;
tzp->no_hwmon = true;
if (!of_property_read_u32(np, "sustainable-power", &prop))
tzp->sustainable_power = prop;
/*
* For now, the thermal framework supports only one sensor per
* thermal zone. Thus, we are considering only the first two
* values as slope and offset.
*/
ret = of_property_read_u32_array(np, "coefficients", coef, ncoef);
if (ret) {
coef[0] = 1;
coef[1] = 0;
}
tzp->slope = coef[0];
tzp->offset = coef[1];
}
static struct device_node *thermal_of_zone_get_by_name(struct thermal_zone_device *tz)
{
struct device_node *np, *tz_np;
np = of_find_node_by_name(NULL, "thermal-zones");
if (!np)
return ERR_PTR(-ENODEV);
tz_np = of_get_child_by_name(np, tz->type);
of_node_put(np);
if (!tz_np)
return ERR_PTR(-ENODEV);
return tz_np;
}
static bool thermal_of_get_cooling_spec(struct device_node *map_np, int index,
struct thermal_cooling_device *cdev,
struct cooling_spec *c)
{
struct of_phandle_args cooling_spec;
int ret, weight = THERMAL_WEIGHT_DEFAULT;
of_property_read_u32(map_np, "contribution", &weight);
ret = of_parse_phandle_with_args(map_np, "cooling-device", "#cooling-cells",
index, &cooling_spec);
if (ret < 0) {
pr_err("Invalid cooling-device entry\n");
return false;
}
of_node_put(cooling_spec.np);
if (cooling_spec.args_count < 2) {
pr_err("wrong reference to cooling device, missing limits\n");
return false;
}
if (cooling_spec.np != cdev->np)
return false;
c->lower = cooling_spec.args[0];
c->upper = cooling_spec.args[1];
c->weight = weight;
return true;
}
static bool thermal_of_should_bind(struct thermal_zone_device *tz,
const struct thermal_trip *trip,
struct thermal_cooling_device *cdev,
struct cooling_spec *c)
{
struct device_node *tz_np, *cm_np, *child;
bool result = false;
tz_np = thermal_of_zone_get_by_name(tz);
if (IS_ERR(tz_np)) {
pr_err("Failed to get node tz by name\n");
return false;
}
cm_np = of_get_child_by_name(tz_np, "cooling-maps");
if (!cm_np)
goto out;
/* Look up the trip and the cdev in the cooling maps. */
for_each_child_of_node(cm_np, child) {
struct device_node *tr_np;
int count, i;
tr_np = of_parse_phandle(child, "trip", 0);
if (tr_np != trip->priv)
continue;
/* The trip has been found, look up the cdev. */
count = of_count_phandle_with_args(child, "cooling-device", "#cooling-cells");
if (count <= 0)
pr_err("Add a cooling_device property with at least one device\n");
for (i = 0; i < count; i++) {
result = thermal_of_get_cooling_spec(child, i, cdev, c);
if (result)
break;
}
of_node_put(child);
break;
}
of_node_put(cm_np);
out:
of_node_put(tz_np);
return result;
}
/**
* thermal_of_zone_unregister - Cleanup the specific allocated ressources
*
* This function disables the thermal zone and frees the different
* ressources allocated specific to the thermal OF.
*
* @tz: a pointer to the thermal zone structure
*/
static void thermal_of_zone_unregister(struct thermal_zone_device *tz)
{
thermal_zone_device_disable(tz);
thermal_zone_device_unregister(tz);
}
/**
* thermal_of_zone_register - Register a thermal zone with device node
* sensor
*
* The thermal_of_zone_register() parses a device tree given a device
* node sensor and identifier. It searches for the thermal zone
* associated to the couple sensor/id and retrieves all the thermal
* zone properties and registers new thermal zone with those
* properties.
*
* @sensor: A device node pointer corresponding to the sensor in the device tree
* @id: An integer as sensor identifier
* @data: A private data to be stored in the thermal zone dedicated private area
* @ops: A set of thermal sensor ops
*
* Return: a valid thermal zone structure pointer on success.
* - EINVAL: if the device tree thermal description is malformed
* - ENOMEM: if one structure can not be allocated
* - Other negative errors are returned by the underlying called functions
*/
static struct thermal_zone_device *thermal_of_zone_register(struct device_node *sensor, int id, void *data,
const struct thermal_zone_device_ops *ops)
{
struct thermal_zone_device_ops of_ops = *ops;
struct thermal_zone_device *tz;
struct thermal_trip *trips;
struct thermal_zone_params tzp = {};
struct device_node *np;
const char *action;
int delay, pdelay;
int ntrips;
int ret;
np = of_thermal_zone_find(sensor, id);
if (IS_ERR(np)) {
if (PTR_ERR(np) != -ENODEV)
pr_err("Failed to find thermal zone for %pOFn id=%d\n", sensor, id);
return ERR_CAST(np);
}
trips = thermal_of_trips_init(np, &ntrips);
if (IS_ERR(trips)) {
pr_err("Failed to find trip points for %pOFn id=%d\n", sensor, id);
ret = PTR_ERR(trips);
goto out_of_node_put;
}
ret = thermal_of_monitor_init(np, &delay, &pdelay);
if (ret) {
pr_err("Failed to initialize monitoring delays from %pOFn\n", np);
goto out_kfree_trips;
}
thermal_of_parameters_init(np, &tzp);
of_ops.should_bind = thermal_of_should_bind;
ret = of_property_read_string(np, "critical-action", &action);
if (!ret)
if (!of_ops.critical && !strcasecmp(action, "reboot"))
of_ops.critical = thermal_zone_device_critical_reboot;
tz = thermal_zone_device_register_with_trips(np->name, trips, ntrips,
data, &of_ops, &tzp,
pdelay, delay);
if (IS_ERR(tz)) {
ret = PTR_ERR(tz);
pr_err("Failed to register thermal zone %pOFn: %d\n", np, ret);
goto out_kfree_trips;
}
of_node_put(np);
kfree(trips);
ret = thermal_zone_device_enable(tz);
if (ret) {
pr_err("Failed to enabled thermal zone '%s', id=%d: %d\n",
tz->type, tz->id, ret);
thermal_of_zone_unregister(tz);
return ERR_PTR(ret);
}
return tz;
out_kfree_trips:
kfree(trips);
out_of_node_put:
of_node_put(np);
return ERR_PTR(ret);
}
static void devm_thermal_of_zone_release(struct device *dev, void *res)
{
thermal_of_zone_unregister(*(struct thermal_zone_device **)res);
}
static int devm_thermal_of_zone_match(struct device *dev, void *res,
void *data)
{
struct thermal_zone_device **r = res;
if (WARN_ON(!r || !*r))
return 0;
return *r == data;
}
/**
* devm_thermal_of_zone_register - register a thermal tied with the sensor life cycle
*
* This function is the device version of the thermal_of_zone_register() function.
*
* @dev: a device structure pointer to sensor to be tied with the thermal zone OF life cycle
* @sensor_id: the sensor identifier
* @data: a pointer to a private data to be stored in the thermal zone 'devdata' field
* @ops: a pointer to the ops structure associated with the sensor
*/
struct thermal_zone_device *devm_thermal_of_zone_register(struct device *dev, int sensor_id, void *data,
const struct thermal_zone_device_ops *ops)
{
struct thermal_zone_device **ptr, *tzd;
ptr = devres_alloc(devm_thermal_of_zone_release, sizeof(*ptr),
GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
tzd = thermal_of_zone_register(dev->of_node, sensor_id, data, ops);
if (IS_ERR(tzd)) {
devres_free(ptr);
return tzd;
}
*ptr = tzd;
devres_add(dev, ptr);
return tzd;
}
EXPORT_SYMBOL_GPL(devm_thermal_of_zone_register);
/**
* devm_thermal_of_zone_unregister - Resource managed version of
* thermal_of_zone_unregister().
* @dev: Device for which which resource was allocated.
* @tz: a pointer to struct thermal_zone where the sensor is registered.
*
* This function removes the sensor callbacks and private data from the
* thermal zone device registered with devm_thermal_zone_of_sensor_register()
* API. It will also silent the zone by remove the .get_temp() and .get_trend()
* thermal zone device callbacks.
* Normally this function will not need to be called and the resource
* management code will ensure that the resource is freed.
*/
void devm_thermal_of_zone_unregister(struct device *dev, struct thermal_zone_device *tz)
{
WARN_ON(devres_release(dev, devm_thermal_of_zone_release,
devm_thermal_of_zone_match, tz));
}
EXPORT_SYMBOL_GPL(devm_thermal_of_zone_unregister);
Codebase Browser
linux