/* * 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 <linux/thermal.h> #include "thermal_core.h" /*** Private data structures to represent thermal device tree data ***/ /** * 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 * @ops: set of callbacks to handle the thermal zone based on DT */ 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; const struct thermal_zone_of_device_ops *ops; }; /*** 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->ops->get_temp) return -EINVAL; return data->ops->get_temp(data->sensor_data, temp); } /** * of_thermal_get_ntrips - function to export number of available trip * points. * @tz: pointer to a thermal zone * * This function is a globally visible wrapper to get number of trip points * stored in the local struct __thermal_zone * * Return: number of available trip points, -ENODEV when data not available */ int of_thermal_get_ntrips(struct thermal_zone_device *tz) { struct __thermal_zone *data = tz->devdata; if (!data || IS_ERR(data)) return -ENODEV; return data->ntrips; } EXPORT_SYMBOL_GPL(of_thermal_get_ntrips); /** * of_thermal_is_trip_valid - function to check if trip point is valid * * @tz: pointer to a thermal zone * @trip: trip point to evaluate * * This function is responsible for checking if passed trip point is valid * * Return: true if trip point is valid, false otherwise */ bool of_thermal_is_trip_valid(struct thermal_zone_device *tz, int trip) { struct __thermal_zone *data = tz->devdata; if (!data || trip >= data->ntrips || trip < 0) return false; return true; } EXPORT_SYMBOL_GPL(of_thermal_is_trip_valid); /** * of_thermal_get_trip_points - function to get access to a globally exported * trip points * * @tz: pointer to a thermal zone * * This function provides a pointer to trip points table * * Return: pointer to trip points table, NULL otherwise */ const struct thermal_trip * of_thermal_get_trip_points(struct thermal_zone_device *tz) { struct __thermal_zone *data = tz->devdata; if (!data) return NULL; return data->trips; } EXPORT_SYMBOL_GPL(of_thermal_get_trip_points); /** * of_thermal_set_emul_temp - function to set emulated temperature * * @tz: pointer to a thermal zone * @temp: temperature to set * * This function gives the ability to set emulated value of temperature, * which is handy for debugging * * Return: zero on success, error code otherwise */ static int of_thermal_set_emul_temp(struct thermal_zone_device *tz, unsigned long temp) { struct __thermal_zone *data = tz->devdata; if (!data->ops || !data->ops->set_emul_temp) return -EINVAL; return data->ops->set_emul_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->ops->get_trend) return -EINVAL; r = data->ops->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->max, tbp->min); 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, const struct thermal_zone_of_device_ops *ops) { 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; if (!ops) return ERR_PTR(-EINVAL); mutex_lock(&tzd->lock); tz->ops = ops; tz->sensor_data = data; tzd->ops->get_temp = of_thermal_get_temp; tzd->ops->get_trend = of_thermal_get_trend; tzd->ops->set_emul_temp = of_thermal_set_emul_temp; 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. * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp. * * 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, const struct thermal_zone_of_device_ops *ops) { struct device_node *np, *child, *sensor_np; struct thermal_zone_device *tzd = ERR_PTR(-ENODEV); np = of_find_node_by_name(NULL, "thermal-zones"); if (!np) return ERR_PTR(-ENODEV); if (!dev || !dev->of_node) { of_node_put(np); return ERR_PTR(-EINVAL); } sensor_np = of_node_get(dev->of_node); for_each_child_of_node(np, child) { struct of_phandle_args sensor_specs; int ret, id; /* Check whether child is enabled or not */ if (!of_device_is_available(child)) continue; /* 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) { tzd = thermal_zone_of_add_sensor(child, sensor_np, data, ops); if (!IS_ERR(tzd)) tzd->ops->set_mode(tzd, THERMAL_DEVICE_ENABLED); of_node_put(sensor_specs.np); of_node_put(child); goto exit; } of_node_put(sensor_specs.np); } exit: of_node_put(sensor_np); of_node_put(np); return tzd; } 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; tzd->ops->set_emul_temp = NULL; tz->ops = 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; of_node_get(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: for (i = 0; i < tz->num_tbps; i++) of_node_put(tz->tbps[i].cooling_device); kfree(tz->tbps); free_trips: for (i = 0; i < tz->ntrips; i++) of_node_put(tz->trips[i].np); kfree(tz->trips); of_node_put(gchild); free_tz: kfree(tz); of_node_put(child); return ERR_PTR(ret); } static inline void of_thermal_free_zone(struct __thermal_zone *tz) { int i; for (i = 0; i < tz->num_tbps; i++) of_node_put(tz->tbps[i].cooling_device); kfree(tz->tbps); for (i = 0; i < tz->ntrips; i++) of_node_put(tz->trips[i].np); 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; /* Check whether child is enabled or not */ if (!of_device_is_available(child)) continue; 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 */ } } of_node_put(np); return 0; exit_free: of_node_put(child); of_node_put(np); 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; /* Check whether child is enabled or not */ if (!of_device_is_available(child)) continue; 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); } of_node_put(np); }