diff options
Diffstat (limited to 'drivers/thermal/of-thermal.c')
| -rw-r--r-- | drivers/thermal/of-thermal.c | 850 |
1 files changed, 850 insertions, 0 deletions
diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c new file mode 100644 index 000000000000..4b2b999b7611 --- /dev/null +++ b/drivers/thermal/of-thermal.c @@ -0,0 +1,850 @@ +/* + * 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->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, + 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); + } +} |