drivers/thermal/st/st_thermal.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * ST Thermal Sensor Driver core routines
   4  * Author: Ajit Pal Singh <ajitpal.singh@st.com>
   5  *
   6  * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/module.h>
  11 #include <linux/of.h>
  12 #include <linux/of_device.h>
  13
  14 #include "st_thermal.h"
  15
  16 /* The Thermal Framework expects millidegrees */
  17 #define mcelsius(temp)                  ((temp) * 1000)
  18
  19 /*
  20  * Function to allocate regfields which are common
  21  * between syscfg and memory mapped based sensors
  22  */
  23 static int st_thermal_alloc_regfields(struct st_thermal_sensor *sensor)
  24 {
  25         struct device *dev = sensor->dev;
  26         struct regmap *regmap = sensor->regmap;
  27         const struct reg_field *reg_fields = sensor->cdata->reg_fields;
  28
  29         sensor->dcorrect = devm_regmap_field_alloc(dev, regmap,
  30                                                    reg_fields[DCORRECT]);
  31
  32         sensor->overflow = devm_regmap_field_alloc(dev, regmap,
  33                                                    reg_fields[OVERFLOW]);
  34
  35         sensor->temp_data = devm_regmap_field_alloc(dev, regmap,
  36                                                     reg_fields[DATA]);
  37
  38         if (IS_ERR(sensor->dcorrect) ||
  39             IS_ERR(sensor->overflow) ||
  40             IS_ERR(sensor->temp_data)) {
  41                 dev_err(dev, "failed to allocate common regfields\n");
  42                 return -EINVAL;
  43         }
  44
  45         return sensor->ops->alloc_regfields(sensor);
  46 }
  47
  48 static int st_thermal_sensor_on(struct st_thermal_sensor *sensor)
  49 {
  50         int ret;
  51         struct device *dev = sensor->dev;
  52
  53         ret = clk_prepare_enable(sensor->clk);
  54         if (ret) {
  55                 dev_err(dev, "failed to enable clk\n");
  56                 return ret;
  57         }
  58
  59         ret = sensor->ops->power_ctrl(sensor, POWER_ON);
  60         if (ret) {
  61                 dev_err(dev, "failed to power on sensor\n");
  62                 clk_disable_unprepare(sensor->clk);
  63         }
  64
  65         return ret;
  66 }
  67
  68 static int st_thermal_sensor_off(struct st_thermal_sensor *sensor)
  69 {
  70         int ret;
  71
  72         ret = sensor->ops->power_ctrl(sensor, POWER_OFF);
  73         if (ret)
  74                 return ret;
  75
  76         clk_disable_unprepare(sensor->clk);
  77
  78         return 0;
  79 }
  80
  81 static int st_thermal_calibration(struct st_thermal_sensor *sensor)
  82 {
  83         int ret;
  84         unsigned int val;
  85         struct device *dev = sensor->dev;
  86
  87         /* Check if sensor calibration data is already written */
  88         ret = regmap_field_read(sensor->dcorrect, &val);
  89         if (ret) {
  90                 dev_err(dev, "failed to read calibration data\n");
  91                 return ret;
  92         }
  93
  94         if (!val) {
  95                 /*
  96                  * Sensor calibration value not set by bootloader,
  97                  * default calibration data to be used
  98                  */
  99                 ret = regmap_field_write(sensor->dcorrect,
 100                                          sensor->cdata->calibration_val);
 101                 if (ret)
 102                         dev_err(dev, "failed to set calibration data\n");
 103         }
 104
 105         return ret;
 106 }
 107
 108 /* Callback to get temperature from HW*/
 109 static int st_thermal_get_temp(struct thermal_zone_device *th, int *temperature)
 110 {
 111         struct st_thermal_sensor *sensor = thermal_zone_device_priv(th);
 112         unsigned int temp;
 113         unsigned int overflow;
 114         int ret;
 115
 116         ret = regmap_field_read(sensor->overflow, &overflow);
 117         if (ret)
 118                 return ret;
 119         if (overflow)
 120                 return -EIO;
 121
 122         ret = regmap_field_read(sensor->temp_data, &temp);
 123         if (ret)
 124                 return ret;
 125
 126         temp += sensor->cdata->temp_adjust_val;
 127         temp = mcelsius(temp);
 128
 129         *temperature = temp;
 130
 131         return 0;
 132 }
 133
 134 static struct thermal_zone_device_ops st_tz_ops = {
 135         .get_temp       = st_thermal_get_temp,
 136 };
 137
 138 static struct thermal_trip trip;
 139
 140 int st_thermal_register(struct platform_device *pdev,
 141                         const struct of_device_id *st_thermal_of_match)
 142 {
 143         struct st_thermal_sensor *sensor;
 144         struct device *dev = &pdev->dev;
 145         struct device_node *np = dev->of_node;
 146         const struct of_device_id *match;
 147
 148         int polling_delay;
 149         int ret;
 150
 151         if (!np) {
 152                 dev_err(dev, "device tree node not found\n");
 153                 return -EINVAL;
 154         }
 155
 156         sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
 157         if (!sensor)
 158                 return -ENOMEM;
 159
 160         sensor->dev = dev;
 161
 162         match = of_match_device(st_thermal_of_match, dev);
 163         if (!(match && match->data))
 164                 return -EINVAL;
 165
 166         sensor->cdata = match->data;
 167         if (!sensor->cdata->ops)
 168                 return -EINVAL;
 169
 170         sensor->ops = sensor->cdata->ops;
 171
 172         ret = (sensor->ops->regmap_init)(sensor);
 173         if (ret)
 174                 return ret;
 175
 176         ret = st_thermal_alloc_regfields(sensor);
 177         if (ret)
 178                 return ret;
 179
 180         sensor->clk = devm_clk_get(dev, "thermal");
 181         if (IS_ERR(sensor->clk)) {
 182                 dev_err(dev, "failed to fetch clock\n");
 183                 return PTR_ERR(sensor->clk);
 184         }
 185
 186         if (sensor->ops->register_enable_irq) {
 187                 ret = sensor->ops->register_enable_irq(sensor);
 188                 if (ret)
 189                         return ret;
 190         }
 191
 192         ret = st_thermal_sensor_on(sensor);
 193         if (ret)
 194                 return ret;
 195
 196         ret = st_thermal_calibration(sensor);
 197         if (ret)
 198                 goto sensor_off;
 199
 200         polling_delay = sensor->ops->register_enable_irq ? 0 : 1000;
 201
 202         trip.temperature = sensor->cdata->crit_temp;
 203         trip.type = THERMAL_TRIP_CRITICAL;
 204
 205         sensor->thermal_dev =
 206                 thermal_zone_device_register_with_trips(dev_name(dev), &trip, 1, 0, sensor,
 207                                                         &st_tz_ops, NULL, 0, polling_delay);
 208         if (IS_ERR(sensor->thermal_dev)) {
 209                 dev_err(dev, "failed to register thermal zone device\n");
 210                 ret = PTR_ERR(sensor->thermal_dev);
 211                 goto sensor_off;
 212         }
 213         ret = thermal_zone_device_enable(sensor->thermal_dev);
 214         if (ret)
 215                 goto tzd_unregister;
 216
 217         platform_set_drvdata(pdev, sensor);
 218
 219         return 0;
 220
 221 tzd_unregister:
 222         thermal_zone_device_unregister(sensor->thermal_dev);
 223 sensor_off:
 224         st_thermal_sensor_off(sensor);
 225
 226         return ret;
 227 }
 228 EXPORT_SYMBOL_GPL(st_thermal_register);
 229
 230 void st_thermal_unregister(struct platform_device *pdev)
 231 {
 232         struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
 233
 234         st_thermal_sensor_off(sensor);
 235         thermal_zone_device_unregister(sensor->thermal_dev);
 236 }
 237 EXPORT_SYMBOL_GPL(st_thermal_unregister);
 238
 239 #ifdef CONFIG_PM_SLEEP
 240 static int st_thermal_suspend(struct device *dev)
 241 {
 242         struct st_thermal_sensor *sensor = dev_get_drvdata(dev);
 243
 244         return st_thermal_sensor_off(sensor);
 245 }
 246
 247 static int st_thermal_resume(struct device *dev)
 248 {
 249         int ret;
 250         struct st_thermal_sensor *sensor = dev_get_drvdata(dev);
 251
 252         ret = st_thermal_sensor_on(sensor);
 253         if (ret)
 254                 return ret;
 255
 256         ret = st_thermal_calibration(sensor);
 257         if (ret)
 258                 return ret;
 259
 260         if (sensor->ops->enable_irq) {
 261                 ret = sensor->ops->enable_irq(sensor);
 262                 if (ret)
 263                         return ret;
 264         }
 265
 266         return 0;
 267 }
 268 #endif
 269
 270 SIMPLE_DEV_PM_OPS(st_thermal_pm_ops, st_thermal_suspend, st_thermal_resume);
 271 EXPORT_SYMBOL_GPL(st_thermal_pm_ops);
 272
 273 MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
 274 MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
 275 MODULE_LICENSE("GPL v2");