drivers/thermal/st/st_thermal.c

   1 /*
   2  * ST Thermal Sensor Driver core routines
   3  * Author: Ajit Pal Singh <ajitpal.singh@st.com>
   4  *
   5  * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  */
  13
  14 #include <linux/clk.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_device.h>
  18
  19 #include "st_thermal.h"
  20
  21 /* The Thermal Framework expects millidegrees */
  22 #define mcelsius(temp)                  ((temp) * 1000)
  23
  24 /*
  25  * Function to allocate regfields which are common
  26  * between syscfg and memory mapped based sensors
  27  */
  28 static int st_thermal_alloc_regfields(struct st_thermal_sensor *sensor)
  29 {
  30         struct device *dev = sensor->dev;
  31         struct regmap *regmap = sensor->regmap;
  32         const struct reg_field *reg_fields = sensor->cdata->reg_fields;
  33
  34         sensor->dcorrect = devm_regmap_field_alloc(dev, regmap,
  35                                                    reg_fields[DCORRECT]);
  36
  37         sensor->overflow = devm_regmap_field_alloc(dev, regmap,
  38                                                    reg_fields[OVERFLOW]);
  39
  40         sensor->temp_data = devm_regmap_field_alloc(dev, regmap,
  41                                                     reg_fields[DATA]);
  42
  43         if (IS_ERR(sensor->dcorrect) ||
  44             IS_ERR(sensor->overflow) ||
  45             IS_ERR(sensor->temp_data)) {
  46                 dev_err(dev, "failed to allocate common regfields\n");
  47                 return -EINVAL;
  48         }
  49
  50         return sensor->ops->alloc_regfields(sensor);
  51 }
  52
  53 static int st_thermal_sensor_on(struct st_thermal_sensor *sensor)
  54 {
  55         int ret;
  56         struct device *dev = sensor->dev;
  57
  58         ret = clk_prepare_enable(sensor->clk);
  59         if (ret) {
  60                 dev_err(dev, "failed to enable clk\n");
  61                 return ret;
  62         }
  63
  64         ret = sensor->ops->power_ctrl(sensor, POWER_ON);
  65         if (ret) {
  66                 dev_err(dev, "failed to power on sensor\n");
  67                 clk_disable_unprepare(sensor->clk);
  68         }
  69
  70         return ret;
  71 }
  72
  73 static int st_thermal_sensor_off(struct st_thermal_sensor *sensor)
  74 {
  75         int ret;
  76
  77         ret = sensor->ops->power_ctrl(sensor, POWER_OFF);
  78         if (ret)
  79                 return ret;
  80
  81         clk_disable_unprepare(sensor->clk);
  82
  83         return 0;
  84 }
  85
  86 static int st_thermal_calibration(struct st_thermal_sensor *sensor)
  87 {
  88         int ret;
  89         unsigned int val;
  90         struct device *dev = sensor->dev;
  91
  92         /* Check if sensor calibration data is already written */
  93         ret = regmap_field_read(sensor->dcorrect, &val);
  94         if (ret) {
  95                 dev_err(dev, "failed to read calibration data\n");
  96                 return ret;
  97         }
  98
  99         if (!val) {
 100                 /*
 101                  * Sensor calibration value not set by bootloader,
 102                  * default calibration data to be used
 103                  */
 104                 ret = regmap_field_write(sensor->dcorrect,
 105                                          sensor->cdata->calibration_val);
 106                 if (ret)
 107                         dev_err(dev, "failed to set calibration data\n");
 108         }
 109
 110         return ret;
 111 }
 112
 113 /* Callback to get temperature from HW*/
 114 static int st_thermal_get_temp(struct thermal_zone_device *th, int *temperature)
 115 {
 116         struct st_thermal_sensor *sensor = th->devdata;
 117         struct device *dev = sensor->dev;
 118         unsigned int temp;
 119         unsigned int overflow;
 120         int ret;
 121
 122         ret = regmap_field_read(sensor->overflow, &overflow);
 123         if (ret)
 124                 return ret;
 125         if (overflow)
 126                 return -EIO;
 127
 128         ret = regmap_field_read(sensor->temp_data, &temp);
 129         if (ret)
 130                 return ret;
 131
 132         temp += sensor->cdata->temp_adjust_val;
 133         temp = mcelsius(temp);
 134
 135         dev_dbg(dev, "temperature: %d\n", temp);
 136
 137         *temperature = temp;
 138
 139         return 0;
 140 }
 141
 142 static int st_thermal_get_trip_type(struct thermal_zone_device *th,
 143                                 int trip, enum thermal_trip_type *type)
 144 {
 145         struct st_thermal_sensor *sensor = th->devdata;
 146         struct device *dev = sensor->dev;
 147
 148         switch (trip) {
 149         case 0:
 150                 *type = THERMAL_TRIP_CRITICAL;
 151                 break;
 152         default:
 153                 dev_err(dev, "invalid trip point\n");
 154                 return -EINVAL;
 155         }
 156
 157         return 0;
 158 }
 159
 160 static int st_thermal_get_trip_temp(struct thermal_zone_device *th,
 161                                     int trip, int *temp)
 162 {
 163         struct st_thermal_sensor *sensor = th->devdata;
 164         struct device *dev = sensor->dev;
 165
 166         switch (trip) {
 167         case 0:
 168                 *temp = mcelsius(sensor->cdata->crit_temp);
 169                 break;
 170         default:
 171                 dev_err(dev, "Invalid trip point\n");
 172                 return -EINVAL;
 173         }
 174
 175         return 0;
 176 }
 177
 178 static struct thermal_zone_device_ops st_tz_ops = {
 179         .get_temp       = st_thermal_get_temp,
 180         .get_trip_type  = st_thermal_get_trip_type,
 181         .get_trip_temp  = st_thermal_get_trip_temp,
 182 };
 183
 184 int st_thermal_register(struct platform_device *pdev,
 185                         const struct of_device_id *st_thermal_of_match)
 186 {
 187         struct st_thermal_sensor *sensor;
 188         struct device *dev = &pdev->dev;
 189         struct device_node *np = dev->of_node;
 190         const struct of_device_id *match;
 191
 192         int polling_delay;
 193         int ret;
 194
 195         if (!np) {
 196                 dev_err(dev, "device tree node not found\n");
 197                 return -EINVAL;
 198         }
 199
 200         sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
 201         if (!sensor)
 202                 return -ENOMEM;
 203
 204         sensor->dev = dev;
 205
 206         match = of_match_device(st_thermal_of_match, dev);
 207         if (!(match && match->data))
 208                 return -EINVAL;
 209
 210         sensor->cdata = match->data;
 211         if (!sensor->cdata->ops)
 212                 return -EINVAL;
 213
 214         sensor->ops = sensor->cdata->ops;
 215
 216         ret = (sensor->ops->regmap_init)(sensor);
 217         if (ret)
 218                 return ret;
 219
 220         ret = st_thermal_alloc_regfields(sensor);
 221         if (ret)
 222                 return ret;
 223
 224         sensor->clk = devm_clk_get(dev, "thermal");
 225         if (IS_ERR(sensor->clk)) {
 226                 dev_err(dev, "failed to fetch clock\n");
 227                 return PTR_ERR(sensor->clk);
 228         }
 229
 230         if (sensor->ops->register_enable_irq) {
 231                 ret = sensor->ops->register_enable_irq(sensor);
 232                 if (ret)
 233                         return ret;
 234         }
 235
 236         ret = st_thermal_sensor_on(sensor);
 237         if (ret)
 238                 return ret;
 239
 240         ret = st_thermal_calibration(sensor);
 241         if (ret)
 242                 goto sensor_off;
 243
 244         polling_delay = sensor->ops->register_enable_irq ? 0 : 1000;
 245
 246         sensor->thermal_dev =
 247                 thermal_zone_device_register(dev_name(dev), 1, 0, sensor,
 248                                              &st_tz_ops, NULL, 0, polling_delay);
 249         if (IS_ERR(sensor->thermal_dev)) {
 250                 dev_err(dev, "failed to register thermal zone device\n");
 251                 ret = PTR_ERR(sensor->thermal_dev);
 252                 goto sensor_off;
 253         }
 254
 255         platform_set_drvdata(pdev, sensor);
 256
 257         return 0;
 258
 259 sensor_off:
 260         st_thermal_sensor_off(sensor);
 261
 262         return ret;
 263 }
 264 EXPORT_SYMBOL_GPL(st_thermal_register);
 265
 266 int st_thermal_unregister(struct platform_device *pdev)
 267 {
 268         struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
 269
 270         st_thermal_sensor_off(sensor);
 271         thermal_zone_device_unregister(sensor->thermal_dev);
 272
 273         return 0;
 274 }
 275 EXPORT_SYMBOL_GPL(st_thermal_unregister);
 276
 277 #ifdef CONFIG_PM_SLEEP
 278 static int st_thermal_suspend(struct device *dev)
 279 {
 280         struct platform_device *pdev = to_platform_device(dev);
 281         struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
 282
 283         return st_thermal_sensor_off(sensor);
 284 }
 285
 286 static int st_thermal_resume(struct device *dev)
 287 {
 288         int ret;
 289         struct platform_device *pdev = to_platform_device(dev);
 290         struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
 291
 292         ret = st_thermal_sensor_on(sensor);
 293         if (ret)
 294                 return ret;
 295
 296         ret = st_thermal_calibration(sensor);
 297         if (ret)
 298                 return ret;
 299
 300         if (sensor->ops->enable_irq) {
 301                 ret = sensor->ops->enable_irq(sensor);
 302                 if (ret)
 303                         return ret;
 304         }
 305
 306         return 0;
 307 }
 308 #endif
 309
 310 SIMPLE_DEV_PM_OPS(st_thermal_pm_ops, st_thermal_suspend, st_thermal_resume);
 311 EXPORT_SYMBOL_GPL(st_thermal_pm_ops);
 312
 313 MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
 314 MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
 315 MODULE_LICENSE("GPL v2");