/*
* of-thermal.c - Generic Thermal Management device tree support.
*
* Copyright (C) 2013 Texas Instruments
* Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
*
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/thermal.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/string.h>
#include "thermal_core.h"
/*** Private data structures to represent thermal device tree data ***/
/**
* struct __thermal_trip - representation of a point in temperature domain
* @np: pointer to struct device_node that this trip point was created from
* @temperature: temperature value in miliCelsius
* @hysteresis: relative hysteresis in miliCelsius
* @type: trip point type
*/
struct __thermal_trip {
struct device_node *np;
unsigned long int temperature;
unsigned long int hysteresis;
enum thermal_trip_type type;
};
/**
* struct __thermal_bind_param - a match between trip and cooling device
* @cooling_device: a pointer to identify the referred cooling device
* @trip_id: the trip point index
* @usage: the percentage (from 0 to 100) of cooling contribution
* @min: minimum cooling state used at this trip point
* @max: maximum cooling state used at this trip point
*/
struct __thermal_bind_params {
struct device_node *cooling_device;
unsigned int trip_id;
unsigned int usage;
unsigned long min;
unsigned long max;
};
/**
* struct __thermal_zone - internal representation of a thermal zone
* @mode: current thermal zone device mode (enabled/disabled)
* @passive_delay: polling interval while passive cooling is activated
* @polling_delay: zone polling interval
* @ntrips: number of trip points
* @trips: an array of trip points (0..ntrips - 1)
* @num_tbps: number of thermal bind params
* @tbps: an array of thermal bind params (0..num_tbps - 1)
* @sensor_data: sensor private data used while reading temperature and trend
* @get_temp: sensor callback to read temperature
* @get_trend: sensor callback to read temperature trend
*/
struct __thermal_zone {
enum thermal_device_mode mode;
int passive_delay;
int polling_delay;
/* trip data */
int ntrips;
struct __thermal_trip *trips;
/* cooling binding data */
int num_tbps;
struct __thermal_bind_params *tbps;
/* sensor interface */
void *sensor_data;
int (*get_temp)(void *, long *);
int (*get_trend)(void *, long *);
};
/*** DT thermal zone device callbacks ***/
static int of_thermal_get_temp(struct thermal_zone_device *tz,
unsigned long *temp)
{
struct __thermal_zone *data = tz->devdata;
if (!data->get_temp)
return -EINVAL;
return data->get_temp(data->sensor_data, temp);
}
static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
enum thermal_trend *trend)
{
struct __thermal_zone *data = tz->devdata;
long dev_trend;
int r;
if (!data->get_trend)
return -EINVAL;
r = data->get_trend(data->sensor_data, &dev_trend);
if (r)
return r;
/* TODO: These intervals might have some thresholds, but in core code */
if (dev_trend > 0)
*trend = THERMAL_TREND_RAISING;
else if (dev_trend < 0)
*trend = THERMAL_TREND_DROPPING;
else
*trend = THERMAL_TREND_STABLE;
return 0;
}
static int of_thermal_bind(struct thermal_zone_device *thermal,
struct thermal_cooling_device *cdev)
{
struct __thermal_zone *data = thermal->devdata;
int i;
if (!data || IS_ERR(data))
return -ENODEV;
/* find where to bind */
for (i = 0; i < data->num_tbps; i++) {
struct __thermal_bind_params *tbp = data->tbps + i;
if (tbp->cooling_device == cdev->np) {
int ret;
ret = thermal_zone_bind_cooling_device(thermal,
tbp->trip_id, cdev,
tbp->min,
tbp->max);
if (ret)
return ret;
}
}
return 0;
}
static int of_thermal_unbind(struct thermal_zone_device *thermal,
struct thermal_cooling_device *cdev)
{
struct __thermal_zone *data = thermal->devdata;
int i;
if (!data || IS_ERR(data))
return -ENODEV;
/* find where to unbind */
for (i = 0; i < data->num_tbps; i++) {
struct __thermal_bind_params *tbp = data->tbps + i;
if (tbp->cooling_device == cdev->np) {
int ret;
ret = thermal_zone_unbind_cooling_device(thermal,
tbp->trip_id, cdev);
if (ret)
return ret;
}
}
return 0;
}
static int of_thermal_get_mode(struct thermal_zone_device *tz,
enum thermal_device_mode *mode)
{
struct __thermal_zone *data = tz->devdata;
*mode = data->mode;
return 0;
}
static int of_thermal_set_mode(struct thermal_zone_device *tz,
enum thermal_device_mode mode)
{
struct __thermal_zone *data = tz->devdata;
mutex_lock(&tz->lock);
if (mode == THERMAL_DEVICE_ENABLED)
tz->polling_delay = data->polling_delay;
else
tz->polling_delay = 0;
mutex_unlock(&tz->lock);
data->mode = mode;
thermal_zone_device_update(tz);
return 0;
}
static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
enum thermal_trip_type *type)
{
struct __thermal_zone *data = tz->devdata;
if (trip >= data->ntrips || trip < 0)
return -EDOM;
*type = data->trips[trip].type;
return 0;
}
static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
unsigned long *temp)
{
struct __thermal_zone *data = tz->devdata;
if (trip >= data->ntrips || trip < 0)
return -EDOM;
*temp = data->trips[trip].temperature;
return 0;
}
static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
unsigned long temp)
{
struct __thermal_zone *data = tz->devdata;
if (trip >= data->ntrips || trip < 0)
return -EDOM;
/* thermal framework should take care of data->mask & (1 << trip) */
data->trips[trip].temperature = temp;
return 0;
}
static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
unsigned long *hyst)
{
struct __thermal_zone *data = tz->devdata;
if (trip >= data->ntrips || trip < 0)
return -EDOM;
*hyst = data->trips[trip].hysteresis;
return 0;
}
static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
unsigned long hyst)
{
struct __thermal_zone *data = tz->devdata;
if (trip >= data->ntrips || trip < 0)
return -EDOM;
/* thermal framework should take care of data->mask & (1 << trip) */
data->trips[trip].hysteresis = hyst;
return 0;
}
static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
unsigned long *temp)
{
struct __thermal_zone *data = tz->devdata;
int i;
for (i = 0; i < data->ntrips; i++)
if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
*temp = data->trips[i].temperature;
return 0;
}
return -EINVAL;
}
static struct thermal_zone_device_ops of_thermal_ops = {
.get_mode = of_thermal_get_mode,
.set_mode = of_thermal_set_mode,
.get_trip_type = of_thermal_get_trip_type,
.get_trip_temp = of_thermal_get_trip_temp,
.set_trip_temp = of_thermal_set_trip_temp,
.get_trip_hyst = of_thermal_get_trip_hyst,
.set_trip_hyst = of_thermal_set_trip_hyst,
.get_crit_temp = of_thermal_get_crit_temp,
.bind = of_thermal_bind,
.unbind = of_thermal_unbind,
};
/*** sensor API ***/
static struct thermal_zone_device *
thermal_zone_of_add_sensor(struct device_node *zone,
struct device_node *sensor, void *data,
int (*get_temp)(void *, long *),
int (*get_trend)(void *, long *))
{
struct thermal_zone_device *tzd;
struct __thermal_zone *tz;
tzd = thermal_zone_get_zone_by_name(zone->name);
if (IS_ERR(tzd))
return ERR_PTR(-EPROBE_DEFER);
tz = tzd->devdata;
mutex_lock(&tzd->lock);
tz->get_temp = get_temp;
tz->get_trend = get_trend;
tz->sensor_data = data;
tzd->ops->get_temp = of_thermal_get_temp;
tzd->ops->get_trend = of_thermal_get_trend;
mutex_unlock(&tzd->lock);
return tzd;
}
/**
* thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
* @dev: a valid struct device pointer of a sensor device. Must contain
* a valid .of_node, for the sensor node.
* @sensor_id: a sensor identifier, in case the sensor IP has more
* than one sensors
* @data: a private pointer (owned by the caller) that will be passed
* back, when a temperature reading is needed.
* @get_temp: a pointer to a function that reads the sensor temperature.
* @get_trend: a pointer to a function that reads the sensor temperature trend.
*
* This function will search the list of thermal zones described in device
* tree and look for the zone that refer to the sensor device pointed by
* @dev->of_node as temperature providers. For the zone pointing to the
* sensor node, the sensor will be added to the DT thermal zone device.
*
* The thermal zone temperature is provided by the @get_temp function
* pointer. When called, it will have the private pointer @data back.
*
* The thermal zone temperature trend is provided by the @get_trend function
* pointer. When called, it will have the private pointer @data back.
*
* TODO:
* 01 - This function must enqueue the new sensor instead of using
* it as the only source of temperature values.
*
* 02 - There must be a way to match the sensor with all thermal zones
* that refer to it.
*
* Return: On success returns a valid struct thermal_zone_device,
* otherwise, it returns a corresponding ERR_PTR(). Caller must
* check the return value with help of IS_ERR() helper.
*/
struct thermal_zone_device *
thermal_zone_of_sensor_register(struct device *dev, int sensor_id,
void *data, int (*get_temp)(void *, long *),
int (*get_trend)(void *, long *))
{
struct device_node *np, *child, *sensor_np;
np = of_find_node_by_name(NULL, "thermal-zones");
if (!np)
return ERR_PTR(-ENODEV);
if (!dev || !dev->of_node)
return ERR_PTR(-EINVAL);
sensor_np = dev->of_node;
for_each_child_of_node(np, child) {
struct of_phandle_args sensor_specs;
int ret, id;
/* For now, thermal framework supports only 1 sensor per zone */
ret = of_parse_phandle_with_args(child, "thermal-sensors",
"#thermal-sensor-cells",
0, &sensor_specs);
if (ret)
continue;
if (sensor_specs.args_count >= 1) {
id = sensor_specs.args[0];
WARN(sensor_specs.args_count > 1,
"%s: too many cells in sensor specifier %d\n",
sensor_specs.np->name, sensor_specs.args_count);
} else {
id = 0;
}
if (sensor_specs.np == sensor_np && id == sensor_id) {
of_node_put(np);
return thermal_zone_of_add_sensor(child, sensor_np,
data,
get_temp,
get_trend);
}
}
of_node_put(np);
return ERR_PTR(-ENODEV);
}
EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
/**
* thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
* @dev: a valid struct device pointer of a sensor device. Must contain
* a valid .of_node, for the sensor node.
* @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
*
* This function removes the sensor callbacks and private data from the
* thermal zone device registered with thermal_zone_of_sensor_register()
* API. It will also silent the zone by remove the .get_temp() and .get_trend()
* thermal zone device callbacks.
*
* TODO: When the support to several sensors per zone is added, this
* function must search the sensor list based on @dev parameter.
*
*/
void thermal_zone_of_sensor_unregister(struct device *dev,
struct thermal_zone_device *tzd)
{
struct __thermal_zone *tz;
if (!dev || !tzd || !tzd->devdata)
return;
tz = tzd->devdata;
/* no __thermal_zone, nothing to be done */
if (!tz)
return;
mutex_lock(&tzd->lock);
tzd->ops->get_temp = NULL;
tzd->ops->get_trend = NULL;
tz->get_temp = NULL;
tz->get_trend = NULL;
tz->sensor_data = NULL;
mutex_unlock(&tzd->lock);
}
EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
/*** functions parsing device tree nodes ***/
/**
* thermal_of_populate_bind_params - parse and fill cooling map data
* @np: DT node containing a cooling-map node
* @__tbp: data structure to be filled with cooling map info
* @trips: array of thermal zone trip points
* @ntrips: number of trip points inside trips.
*
* This function parses a cooling-map type of node represented by
* @np parameter and fills the read data into @__tbp data structure.
* It needs the already parsed array of trip points of the thermal zone
* in consideration.
*
* Return: 0 on success, proper error code otherwise
*/
static int thermal_of_populate_bind_params(struct device_node *np,
struct __thermal_bind_params *__tbp,
struct __thermal_trip *trips,
int ntrips)
{
struct of_phandle_args cooling_spec;
struct device_node *trip;
int ret, i;
u32 prop;
/* Default weight. Usage is optional */
__tbp->usage = 0;
ret = of_property_read_u32(np, "contribution", &prop);
if (ret == 0)
__tbp->usage = prop;
trip = of_parse_phandle(np, "trip", 0);
if (!trip) {
pr_err("missing trip property\n");
return -ENODEV;
}
/* match using device_node */
for (i = 0; i < ntrips; i++)
if (trip == trips[i].np) {
__tbp->trip_id = i;
break;
}
if (i == ntrips) {
ret = -ENODEV;
goto end;
}
ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
0, &cooling_spec);
if (ret < 0) {
pr_err("missing cooling_device property\n");
goto end;
}
__tbp->cooling_device = cooling_spec.np;
if (cooling_spec.args_count >= 2) { /* at least min and max */
__tbp->min = cooling_spec.args[0];
__tbp->max = cooling_spec.args[1];
} else {
pr_err("wrong reference to cooling device, missing limits\n");
}
end:
of_node_put(trip);
return ret;
}
/**
* 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;
}
/**
* thermal_of_populate_trip - parse and fill one trip point data
* @np: DT node containing a trip point node
* @trip: trip point data structure to be filled up
*
* This function parses a trip point type of node represented by
* @np parameter and fills the read data into @trip data structure.
*
* Return: 0 on success, proper error code otherwise
*/
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;
}
/* Required for cooling map matching */
trip->np = np;
return 0;
}
/**
* thermal_of_build_thermal_zone - parse and fill one thermal zone data
* @np: DT node containing a thermal zone node
*
* This function parses a thermal zone type of node represented by
* @np parameter and fills the read data into a __thermal_zone data structure
* and return this pointer.
*
* TODO: Missing properties to parse: thermal-sensor-names and coefficients
*
* Return: On success returns a valid struct __thermal_zone,
* otherwise, it returns a corresponding ERR_PTR(). Caller must
* check the return value with help of IS_ERR() helper.
*/
static struct __thermal_zone *
thermal_of_build_thermal_zone(struct device_node *np)
{
struct device_node *child = NULL, *gchild;
struct __thermal_zone *tz;
int ret, i;
u32 prop;
if (!np) {
pr_err("no thermal zone np\n");
return ERR_PTR(-EINVAL);
}
tz = kzalloc(sizeof(*tz), GFP_KERNEL);
if (!tz)
return ERR_PTR(-ENOMEM);
ret = of_property_read_u32(np, "polling-delay-passive", &prop);
if (ret < 0) {
pr_err("missing polling-delay-passive property\n");
goto free_tz;
}
tz->passive_delay = prop;
ret = of_property_read_u32(np, "polling-delay", &prop);
if (ret < 0) {
pr_err("missing polling-delay property\n");
goto free_tz;
}
tz->polling_delay = prop;
/* trips */
child = of_get_child_by_name(np, "trips");
/* No trips provided */
if (!child)
goto finish;
tz->ntrips = of_get_child_count(child);
if (tz->ntrips == 0) /* must have at least one child */
goto finish;
tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
if (!tz->trips) {
ret = -ENOMEM;
goto free_tz;
}
i = 0;
for_each_child_of_node(child, gchild) {
ret = thermal_of_populate_trip(gchild, &tz->trips[i++]);
if (ret)
goto free_trips;
}
of_node_put(child);
/* cooling-maps */
child = of_get_child_by_name(np, "cooling-maps");
/* cooling-maps not provided */
if (!child)
goto finish;
tz->num_tbps = of_get_child_count(child);
if (tz->num_tbps == 0)
goto finish;
tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
if (!tz->tbps) {
ret = -ENOMEM;
goto free_trips;
}
i = 0;
for_each_child_of_node(child, gchild)
ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
tz->trips, tz->ntrips);
if (ret)
goto free_tbps;
finish:
of_node_put(child);
tz->mode = THERMAL_DEVICE_DISABLED;
return tz;
free_tbps:
kfree(tz->tbps);
free_trips:
kfree(tz->trips);
free_tz:
kfree(tz);
of_node_put(child);
return ERR_PTR(ret);
}
static inline void of_thermal_free_zone(struct __thermal_zone *tz)
{
kfree(tz->tbps);
kfree(tz->trips);
kfree(tz);
}
/**
* of_parse_thermal_zones - parse device tree thermal data
*
* Initialization function that can be called by machine initialization
* code to parse thermal data and populate the thermal framework
* with hardware thermal zones info. This function only parses thermal zones.
* Cooling devices and sensor devices nodes are supposed to be parsed
* by their respective drivers.
*
* Return: 0 on success, proper error code otherwise
*
*/
int __init of_parse_thermal_zones(void)
{
struct device_node *np, *child;
struct __thermal_zone *tz;
struct thermal_zone_device_ops *ops;
np = of_find_node_by_name(NULL, "thermal-zones");
if (!np) {
pr_debug("unable to find thermal zones\n");
return 0; /* Run successfully on systems without thermal DT */
}
for_each_child_of_node(np, child) {
struct thermal_zone_device *zone;
struct thermal_zone_params *tzp;
tz = thermal_of_build_thermal_zone(child);
if (IS_ERR(tz)) {
pr_err("failed to build thermal zone %s: %ld\n",
child->name,
PTR_ERR(tz));
continue;
}
ops = kmemdup(&of_thermal_ops, sizeof(*ops), GFP_KERNEL);
if (!ops)
goto exit_free;
tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
if (!tzp) {
kfree(ops);
goto exit_free;
}
/* No hwmon because there might be hwmon drivers registering */
tzp->no_hwmon = true;
zone = thermal_zone_device_register(child->name, tz->ntrips,
0, tz,
ops, tzp,
tz->passive_delay,
tz->polling_delay);
if (IS_ERR(zone)) {
pr_err("Failed to build %s zone %ld\n", child->name,
PTR_ERR(zone));
kfree(tzp);
kfree(ops);
of_thermal_free_zone(tz);
/* attempting to build remaining zones still */
}
}
return 0;
exit_free:
of_thermal_free_zone(tz);
/* no memory available, so free what we have built */
of_thermal_destroy_zones();
return -ENOMEM;
}
/**
* of_thermal_destroy_zones - remove all zones parsed and allocated resources
*
* Finds all zones parsed and added to the thermal framework and remove them
* from the system, together with their resources.
*
*/
void of_thermal_destroy_zones(void)
{
struct device_node *np, *child;
np = of_find_node_by_name(NULL, "thermal-zones");
if (!np) {
pr_err("unable to find thermal zones\n");
return;
}
for_each_child_of_node(np, child) {
struct thermal_zone_device *zone;
zone = thermal_zone_get_zone_by_name(child->name);
if (IS_ERR(zone))
continue;
thermal_zone_device_unregister(zone);
kfree(zone->tzp);
kfree(zone->ops);
of_thermal_free_zone(zone->devdata);
}
}