drivers/thermal/ti-soc-thermal/ti-thermal-common.c

   1 /*
   2  * OMAP thermal driver interface
   3  *
   4  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
   5  * Contact:
   6  *   Eduardo Valentin <eduardo.valentin@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  20  * 02110-1301 USA
  21  *
  22  */
  23
  24 #include <linux/device.h>
  25 #include <linux/err.h>
  26 #include <linux/mutex.h>
  27 #include <linux/gfp.h>
  28 #include <linux/kernel.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/thermal.h>
  31 #include <linux/cpufreq.h>
  32 #include <linux/cpumask.h>
  33 #include <linux/cpu_cooling.h>
  34 #include <linux/of.h>
  35
  36 #include "ti-thermal.h"
  37 #include "ti-bandgap.h"
  38
  39 /* common data structures */
  40 struct ti_thermal_data {
  41         struct cpufreq_policy *policy;
  42         struct thermal_zone_device *ti_thermal;
  43         struct thermal_zone_device *pcb_tz;
  44         struct thermal_cooling_device *cool_dev;
  45         struct ti_bandgap *bgp;
  46         enum thermal_device_mode mode;
  47         struct work_struct thermal_wq;
  48         int sensor_id;
  49         bool our_zone;
  50 };
  51
  52 static void ti_thermal_work(struct work_struct *work)
  53 {
  54         struct ti_thermal_data *data = container_of(work,
  55                                         struct ti_thermal_data, thermal_wq);
  56
  57         thermal_zone_device_update(data->ti_thermal, THERMAL_EVENT_UNSPECIFIED);
  58
  59         dev_dbg(&data->ti_thermal->device, "updated thermal zone %s\n",
  60                 data->ti_thermal->type);
  61 }
  62
  63 /**
  64  * ti_thermal_hotspot_temperature - returns sensor extrapolated temperature
  65  * @t:  omap sensor temperature
  66  * @s:  omap sensor slope value
  67  * @c:  omap sensor const value
  68  */
  69 static inline int ti_thermal_hotspot_temperature(int t, int s, int c)
  70 {
  71         int delta = t * s / 1000 + c;
  72
  73         if (delta < 0)
  74                 delta = 0;
  75
  76         return t + delta;
  77 }
  78
  79 /* thermal zone ops */
  80 /* Get temperature callback function for thermal zone */
  81 static inline int __ti_thermal_get_temp(void *devdata, int *temp)
  82 {
  83         struct thermal_zone_device *pcb_tz = NULL;
  84         struct ti_thermal_data *data = devdata;
  85         struct ti_bandgap *bgp;
  86         const struct ti_temp_sensor *s;
  87         int ret, tmp, slope, constant;
  88         int pcb_temp;
  89
  90         if (!data)
  91                 return 0;
  92
  93         bgp = data->bgp;
  94         s = &bgp->conf->sensors[data->sensor_id];
  95
  96         ret = ti_bandgap_read_temperature(bgp, data->sensor_id, &tmp);
  97         if (ret)
  98                 return ret;
  99
 100         /* Default constants */
 101         slope = thermal_zone_get_slope(data->ti_thermal);
 102         constant = thermal_zone_get_offset(data->ti_thermal);
 103
 104         pcb_tz = data->pcb_tz;
 105         /* In case pcb zone is available, use the extrapolation rule with it */
 106         if (!IS_ERR(pcb_tz)) {
 107                 ret = thermal_zone_get_temp(pcb_tz, &pcb_temp);
 108                 if (!ret) {
 109                         tmp -= pcb_temp; /* got a valid PCB temp */
 110                         slope = s->slope_pcb;
 111                         constant = s->constant_pcb;
 112                 } else {
 113                         dev_err(bgp->dev,
 114                                 "Failed to read PCB state. Using defaults\n");
 115                         ret = 0;
 116                 }
 117         }
 118         *temp = ti_thermal_hotspot_temperature(tmp, slope, constant);
 119
 120         return ret;
 121 }
 122
 123 static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
 124                                       int *temp)
 125 {
 126         struct ti_thermal_data *data = thermal->devdata;
 127
 128         return __ti_thermal_get_temp(data, temp);
 129 }
 130
 131 static int __ti_thermal_get_trend(void *p, int trip, enum thermal_trend *trend)
 132 {
 133         struct ti_thermal_data *data = p;
 134         struct ti_bandgap *bgp;
 135         int id, tr, ret = 0;
 136
 137         bgp = data->bgp;
 138         id = data->sensor_id;
 139
 140         ret = ti_bandgap_get_trend(bgp, id, &tr);
 141         if (ret)
 142                 return ret;
 143
 144         if (tr > 0)
 145                 *trend = THERMAL_TREND_RAISING;
 146         else if (tr < 0)
 147                 *trend = THERMAL_TREND_DROPPING;
 148         else
 149                 *trend = THERMAL_TREND_STABLE;
 150
 151         return 0;
 152 }
 153
 154 static const struct thermal_zone_of_device_ops ti_of_thermal_ops = {
 155         .get_temp = __ti_thermal_get_temp,
 156         .get_trend = __ti_thermal_get_trend,
 157 };
 158
 159 static struct ti_thermal_data
 160 *ti_thermal_build_data(struct ti_bandgap *bgp, int id)
 161 {
 162         struct ti_thermal_data *data;
 163
 164         data = devm_kzalloc(bgp->dev, sizeof(*data), GFP_KERNEL);
 165         if (!data) {
 166                 dev_err(bgp->dev, "kzalloc fail\n");
 167                 return NULL;
 168         }
 169         data->sensor_id = id;
 170         data->bgp = bgp;
 171         data->mode = THERMAL_DEVICE_ENABLED;
 172         /* pcb_tz will be either valid or PTR_ERR() */
 173         data->pcb_tz = thermal_zone_get_zone_by_name("pcb");
 174         INIT_WORK(&data->thermal_wq, ti_thermal_work);
 175
 176         return data;
 177 }
 178
 179 int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
 180                              char *domain)
 181 {
 182         struct ti_thermal_data *data;
 183
 184         data = ti_bandgap_get_sensor_data(bgp, id);
 185
 186         if (!data || IS_ERR(data))
 187                 data = ti_thermal_build_data(bgp, id);
 188
 189         if (!data)
 190                 return -EINVAL;
 191
 192         /* in case this is specified by DT */
 193         data->ti_thermal = devm_thermal_zone_of_sensor_register(bgp->dev, id,
 194                                         data, &ti_of_thermal_ops);
 195         if (IS_ERR(data->ti_thermal)) {
 196                 dev_err(bgp->dev, "thermal zone device is NULL\n");
 197                 return PTR_ERR(data->ti_thermal);
 198         }
 199
 200         ti_bandgap_set_sensor_data(bgp, id, data);
 201         ti_bandgap_write_update_interval(bgp, data->sensor_id,
 202                                         data->ti_thermal->polling_delay);
 203
 204         return 0;
 205 }
 206
 207 int ti_thermal_remove_sensor(struct ti_bandgap *bgp, int id)
 208 {
 209         struct ti_thermal_data *data;
 210
 211         data = ti_bandgap_get_sensor_data(bgp, id);
 212
 213         if (data && data->ti_thermal) {
 214                 if (data->our_zone)
 215                         thermal_zone_device_unregister(data->ti_thermal);
 216         }
 217
 218         return 0;
 219 }
 220
 221 int ti_thermal_report_sensor_temperature(struct ti_bandgap *bgp, int id)
 222 {
 223         struct ti_thermal_data *data;
 224
 225         data = ti_bandgap_get_sensor_data(bgp, id);
 226
 227         schedule_work(&data->thermal_wq);
 228
 229         return 0;
 230 }
 231
 232 int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
 233 {
 234         struct ti_thermal_data *data;
 235         struct device_node *np = bgp->dev->of_node;
 236
 237         /*
 238          * We are assuming here that if one deploys the zone
 239          * using DT, then it must be aware that the cooling device
 240          * loading has to happen via cpufreq driver.
 241          */
 242         if (of_find_property(np, "#thermal-sensor-cells", NULL))
 243                 return 0;
 244
 245         data = ti_bandgap_get_sensor_data(bgp, id);
 246         if (!data || IS_ERR(data))
 247                 data = ti_thermal_build_data(bgp, id);
 248
 249         if (!data)
 250                 return -EINVAL;
 251
 252         data->policy = cpufreq_cpu_get(0);
 253         if (!data->policy) {
 254                 pr_debug("%s: CPUFreq policy not found\n", __func__);
 255                 return -EPROBE_DEFER;
 256         }
 257
 258         /* Register cooling device */
 259         data->cool_dev = cpufreq_cooling_register(data->policy);
 260         if (IS_ERR(data->cool_dev)) {
 261                 int ret = PTR_ERR(data->cool_dev);
 262                 dev_err(bgp->dev, "Failed to register cpu cooling device %d\n",
 263                         ret);
 264                 cpufreq_cpu_put(data->policy);
 265
 266                 return ret;
 267         }
 268         ti_bandgap_set_sensor_data(bgp, id, data);
 269
 270         return 0;
 271 }
 272
 273 int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id)
 274 {
 275         struct ti_thermal_data *data;
 276
 277         data = ti_bandgap_get_sensor_data(bgp, id);
 278
 279         if (data) {
 280                 cpufreq_cooling_unregister(data->cool_dev);
 281                 if (data->policy)
 282                         cpufreq_cpu_put(data->policy);
 283         }
 284
 285         return 0;
 286 }