kernel/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,
 115                 unsigned long *temperature)
 116 {
 117         struct st_thermal_sensor *sensor = th->devdata;
 118         struct device *dev = sensor->dev;
 119         unsigned int temp;
 120         unsigned int overflow;
 121         int ret;
 122
 123         ret = regmap_field_read(sensor->overflow, &overflow);
 124         if (ret)
 125                 return ret;
 126         if (overflow)
 127                 return -EIO;
 128
 129         ret = regmap_field_read(sensor->temp_data, &temp);
 130         if (ret)
 131                 return ret;
 132
 133         temp += sensor->cdata->temp_adjust_val;
 134         temp = mcelsius(temp);
 135
 136         dev_dbg(dev, "temperature: %d\n", temp);
 137
 138         *temperature = temp;
 139
 140         return 0;
 141 }
 142
 143 static int st_thermal_get_trip_type(struct thermal_zone_device *th,
 144                                 int trip, enum thermal_trip_type *type)
 145 {
 146         struct st_thermal_sensor *sensor = th->devdata;
 147         struct device *dev = sensor->dev;
 148
 149         switch (trip) {
 150         case 0:
 151                 *type = THERMAL_TRIP_CRITICAL;
 152                 break;
 153         default:
 154                 dev_err(dev, "invalid trip point\n");
 155                 return -EINVAL;
 156         }
 157
 158         return 0;
 159 }
 160
 161 static int st_thermal_get_trip_temp(struct thermal_zone_device *th,
 162                                     int trip, unsigned long *temp)
 163 {
 164         struct st_thermal_sensor *sensor = th->devdata;
 165         struct device *dev = sensor->dev;
 166
 167         switch (trip) {
 168         case 0:
 169                 *temp = mcelsius(sensor->cdata->crit_temp);
 170                 break;
 171         default:
 172                 dev_err(dev, "Invalid trip point\n");
 173                 return -EINVAL;
 174         }
 175
 176         return 0;
 177 }
 178
 179 static struct thermal_zone_device_ops st_tz_ops = {
 180         .get_temp       = st_thermal_get_temp,
 181         .get_trip_type  = st_thermal_get_trip_type,
 182         .get_trip_temp  = st_thermal_get_trip_temp,
 183 };
 184
 185 int st_thermal_register(struct platform_device *pdev,
 186                         const struct of_device_id *st_thermal_of_match)
 187 {
 188         struct st_thermal_sensor *sensor;
 189         struct device *dev = &pdev->dev;
 190         struct device_node *np = dev->of_node;
 191         const struct of_device_id *match;
 192
 193         int polling_delay;
 194         int ret;
 195
 196         if (!np) {
 197                 dev_err(dev, "device tree node not found\n");
 198                 return -EINVAL;
 199         }
 200
 201         sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
 202         if (!sensor)
 203                 return -ENOMEM;
 204
 205         sensor->dev = dev;
 206
 207         match = of_match_device(st_thermal_of_match, dev);
 208         if (!(match && match->data))
 209                 return -EINVAL;
 210
 211         sensor->cdata = match->data;
 212         if (!sensor->cdata->ops)
 213                 return -EINVAL;
 214
 215         sensor->ops = sensor->cdata->ops;
 216
 217         ret = sensor->ops->regmap_init(sensor);
 218         if (ret)
 219                 return ret;
 220
 221         ret = st_thermal_alloc_regfields(sensor);
 222         if (ret)
 223                 return ret;
 224
 225         sensor->clk = devm_clk_get(dev, "thermal");
 226         if (IS_ERR(sensor->clk)) {
 227                 dev_err(dev, "failed to fetch clock\n");
 228                 return PTR_ERR(sensor->clk);
 229         }
 230
 231         if (sensor->ops->register_enable_irq) {
 232                 ret = sensor->ops->register_enable_irq(sensor);
 233                 if (ret)
 234                         return ret;
 235         }
 236
 237         ret = st_thermal_sensor_on(sensor);
 238         if (ret)
 239                 return ret;
 240
 241         ret = st_thermal_calibration(sensor);
 242         if (ret)
 243                 goto sensor_off;
 244
 245         polling_delay = sensor->ops->register_enable_irq ? 0 : 1000;
 246
 247         sensor->thermal_dev =
 248                 thermal_zone_device_register(dev_name(dev), 1, 0, sensor,
 249                                              &st_tz_ops, NULL, 0, polling_delay);
 250         if (IS_ERR(sensor->thermal_dev)) {
 251                 dev_err(dev, "failed to register thermal zone device\n");
 252                 ret = PTR_ERR(sensor->thermal_dev);
 253                 goto sensor_off;
 254         }
 255
 256         platform_set_drvdata(pdev, sensor);
 257
 258         return 0;
 259
 260 sensor_off:
 261         st_thermal_sensor_off(sensor);
 262
 263         return ret;
 264 }
 265 EXPORT_SYMBOL_GPL(st_thermal_register);
 266
 267 int st_thermal_unregister(struct platform_device *pdev)
 268 {
 269         struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
 270
 271         st_thermal_sensor_off(sensor);
 272         thermal_zone_device_unregister(sensor->thermal_dev);
 273
 274         return 0;
 275 }
 276 EXPORT_SYMBOL_GPL(st_thermal_unregister);
 277
 278 #ifdef CONFIG_PM_SLEEP
 279 static int st_thermal_suspend(struct device *dev)
 280 {
 281         struct platform_device *pdev = to_platform_device(dev);
 282         struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
 283
 284         return st_thermal_sensor_off(sensor);
 285 }
 286
 287 static int st_thermal_resume(struct device *dev)
 288 {
 289         int ret;
 290         struct platform_device *pdev = to_platform_device(dev);
 291         struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
 292
 293         ret = st_thermal_sensor_on(sensor);
 294         if (ret)
 295                 return ret;
 296
 297         ret = st_thermal_calibration(sensor);
 298         if (ret)
 299                 return ret;
 300
 301         if (sensor->ops->enable_irq) {
 302                 ret = sensor->ops->enable_irq(sensor);
 303                 if (ret)
 304                         return ret;
 305         }
 306
 307         return 0;
 308 }
 309 #endif
 310
 311 SIMPLE_DEV_PM_OPS(st_thermal_pm_ops, st_thermal_suspend, st_thermal_resume);
 312 EXPORT_SYMBOL_GPL(st_thermal_pm_ops);
 313
 314 MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
 315 MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
 316 MODULE_LICENSE("GPL v2");