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