drivers/thermal/da9062-thermal.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Thermal device driver for DA9062 and DA9061
   4  * Copyright (C) 2017  Dialog Semiconductor
   5  */
   6
   7 /* When over-temperature is reached, an interrupt from the device will be
   8  * triggered. Following this event the interrupt will be disabled and
   9  * periodic transmission of uevents (HOT trip point) should define the
  10  * first level of temperature supervision. It is expected that any final
  11  * implementation of the thermal driver will include a .notify() function
  12  * to implement these uevents to userspace.
  13  *
  14  * These uevents are intended to indicate non-invasive temperature control
  15  * of the system, where the necessary measures for cooling are the
  16  * responsibility of the host software. Once the temperature falls again,
  17  * the IRQ is re-enabled so the start of a new over-temperature event can
  18  * be detected without constant software monitoring.
  19  */
  20
  21 #include <linux/errno.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/module.h>
  24 #include <linux/of.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/regmap.h>
  27 #include <linux/thermal.h>
  28 #include <linux/workqueue.h>
  29
  30 #include <linux/mfd/da9062/core.h>
  31 #include <linux/mfd/da9062/registers.h>
  32
  33 /* Minimum, maximum and default polling millisecond periods are provided
  34  * here as an example. It is expected that any final implementation to also
  35  * include a modification of these settings to match the required
  36  * application.
  37  */
  38 #define DA9062_DEFAULT_POLLING_MS_PERIOD        3000
  39 #define DA9062_MAX_POLLING_MS_PERIOD            10000
  40 #define DA9062_MIN_POLLING_MS_PERIOD            1000
  41
  42 #define DA9062_MILLI_CELSIUS(t)                 ((t) * 1000)
  43
  44 struct da9062_thermal_config {
  45         const char *name;
  46 };
  47
  48 struct da9062_thermal {
  49         struct da9062 *hw;
  50         struct delayed_work work;
  51         struct thermal_zone_device *zone;
  52         struct mutex lock; /* protection for da9062_thermal temperature */
  53         int temperature;
  54         int irq;
  55         const struct da9062_thermal_config *config;
  56         struct device *dev;
  57 };
  58
  59 static void da9062_thermal_poll_on(struct work_struct *work)
  60 {
  61         struct da9062_thermal *thermal = container_of(work,
  62                                                 struct da9062_thermal,
  63                                                 work.work);
  64         unsigned long delay;
  65         unsigned int val;
  66         int ret;
  67
  68         /* clear E_TEMP */
  69         ret = regmap_write(thermal->hw->regmap,
  70                            DA9062AA_EVENT_B,
  71                            DA9062AA_E_TEMP_MASK);
  72         if (ret < 0) {
  73                 dev_err(thermal->dev,
  74                         "Cannot clear the TJUNC temperature status\n");
  75                 goto err_enable_irq;
  76         }
  77
  78         /* Now read E_TEMP again: it is acting like a status bit.
  79          * If over-temperature, then this status will be true.
  80          * If not over-temperature, this status will be false.
  81          */
  82         ret = regmap_read(thermal->hw->regmap,
  83                           DA9062AA_EVENT_B,
  84                           &val);
  85         if (ret < 0) {
  86                 dev_err(thermal->dev,
  87                         "Cannot check the TJUNC temperature status\n");
  88                 goto err_enable_irq;
  89         }
  90
  91         if (val & DA9062AA_E_TEMP_MASK) {
  92                 mutex_lock(&thermal->lock);
  93                 thermal->temperature = DA9062_MILLI_CELSIUS(125);
  94                 mutex_unlock(&thermal->lock);
  95                 thermal_zone_device_update(thermal->zone,
  96                                            THERMAL_EVENT_UNSPECIFIED);
  97
  98                 delay = msecs_to_jiffies(thermal->zone->passive_delay);
  99                 queue_delayed_work(system_freezable_wq, &thermal->work, delay);
 100                 return;
 101         }
 102
 103         mutex_lock(&thermal->lock);
 104         thermal->temperature = DA9062_MILLI_CELSIUS(0);
 105         mutex_unlock(&thermal->lock);
 106         thermal_zone_device_update(thermal->zone,
 107                                    THERMAL_EVENT_UNSPECIFIED);
 108
 109 err_enable_irq:
 110         enable_irq(thermal->irq);
 111 }
 112
 113 static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
 114 {
 115         struct da9062_thermal *thermal = data;
 116
 117         disable_irq_nosync(thermal->irq);
 118         queue_delayed_work(system_freezable_wq, &thermal->work, 0);
 119
 120         return IRQ_HANDLED;
 121 }
 122
 123 static int da9062_thermal_get_trip_type(struct thermal_zone_device *z,
 124                                         int trip,
 125                                         enum thermal_trip_type *type)
 126 {
 127         struct da9062_thermal *thermal = z->devdata;
 128
 129         switch (trip) {
 130         case 0:
 131                 *type = THERMAL_TRIP_HOT;
 132                 break;
 133         default:
 134                 dev_err(thermal->dev,
 135                         "Driver does not support more than 1 trip-wire\n");
 136                 return -EINVAL;
 137         }
 138
 139         return 0;
 140 }
 141
 142 static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z,
 143                                         int trip,
 144                                         int *temp)
 145 {
 146         struct da9062_thermal *thermal = z->devdata;
 147
 148         switch (trip) {
 149         case 0:
 150                 *temp = DA9062_MILLI_CELSIUS(125);
 151                 break;
 152         default:
 153                 dev_err(thermal->dev,
 154                         "Driver does not support more than 1 trip-wire\n");
 155                 return -EINVAL;
 156         }
 157
 158         return 0;
 159 }
 160
 161 static int da9062_thermal_get_temp(struct thermal_zone_device *z,
 162                                    int *temp)
 163 {
 164         struct da9062_thermal *thermal = z->devdata;
 165
 166         mutex_lock(&thermal->lock);
 167         *temp = thermal->temperature;
 168         mutex_unlock(&thermal->lock);
 169
 170         return 0;
 171 }
 172
 173 static struct thermal_zone_device_ops da9062_thermal_ops = {
 174         .get_temp       = da9062_thermal_get_temp,
 175         .get_trip_type  = da9062_thermal_get_trip_type,
 176         .get_trip_temp  = da9062_thermal_get_trip_temp,
 177 };
 178
 179 static const struct da9062_thermal_config da9062_config = {
 180         .name = "da9062-thermal",
 181 };
 182
 183 static const struct of_device_id da9062_compatible_reg_id_table[] = {
 184         { .compatible = "dlg,da9062-thermal", .data = &da9062_config },
 185         { },
 186 };
 187
 188 MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
 189
 190 static int da9062_thermal_probe(struct platform_device *pdev)
 191 {
 192         struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
 193         struct da9062_thermal *thermal;
 194         unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
 195         const struct of_device_id *match;
 196         int ret = 0;
 197
 198         match = of_match_node(da9062_compatible_reg_id_table,
 199                               pdev->dev.of_node);
 200         if (!match)
 201                 return -ENXIO;
 202
 203         if (pdev->dev.of_node) {
 204                 if (!of_property_read_u32(pdev->dev.of_node,
 205                                           "polling-delay-passive",
 206                                           &pp_tmp)) {
 207                         if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
 208                             pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
 209                                 dev_warn(&pdev->dev,
 210                                          "Out-of-range polling period %d ms\n",
 211                                          pp_tmp);
 212                                 pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
 213                         }
 214                 }
 215         }
 216
 217         thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
 218                                GFP_KERNEL);
 219         if (!thermal) {
 220                 ret = -ENOMEM;
 221                 goto err;
 222         }
 223
 224         thermal->config = match->data;
 225         thermal->hw = chip;
 226         thermal->dev = &pdev->dev;
 227
 228         INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
 229         mutex_init(&thermal->lock);
 230
 231         thermal->zone = thermal_zone_device_register(thermal->config->name,
 232                                         1, 0, thermal,
 233                                         &da9062_thermal_ops, NULL, pp_tmp,
 234                                         0);
 235         if (IS_ERR(thermal->zone)) {
 236                 dev_err(&pdev->dev, "Cannot register thermal zone device\n");
 237                 ret = PTR_ERR(thermal->zone);
 238                 goto err;
 239         }
 240         ret = thermal_zone_device_enable(thermal->zone);
 241         if (ret) {
 242                 dev_err(&pdev->dev, "Cannot enable thermal zone device\n");
 243                 goto err_zone;
 244         }
 245
 246         dev_dbg(&pdev->dev,
 247                 "TJUNC temperature polling period set at %d ms\n",
 248                 thermal->zone->passive_delay);
 249
 250         ret = platform_get_irq_byname(pdev, "THERMAL");
 251         if (ret < 0) {
 252                 dev_err(&pdev->dev, "Failed to get platform IRQ.\n");
 253                 goto err_zone;
 254         }
 255         thermal->irq = ret;
 256
 257         ret = request_threaded_irq(thermal->irq, NULL,
 258                                    da9062_thermal_irq_handler,
 259                                    IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 260                                    "THERMAL", thermal);
 261         if (ret) {
 262                 dev_err(&pdev->dev,
 263                         "Failed to request thermal device IRQ.\n");
 264                 goto err_zone;
 265         }
 266
 267         platform_set_drvdata(pdev, thermal);
 268         return 0;
 269
 270 err_zone:
 271         thermal_zone_device_unregister(thermal->zone);
 272 err:
 273         return ret;
 274 }
 275
 276 static int da9062_thermal_remove(struct platform_device *pdev)
 277 {
 278         struct  da9062_thermal *thermal = platform_get_drvdata(pdev);
 279
 280         free_irq(thermal->irq, thermal);
 281         cancel_delayed_work_sync(&thermal->work);
 282         thermal_zone_device_unregister(thermal->zone);
 283         return 0;
 284 }
 285
 286 static struct platform_driver da9062_thermal_driver = {
 287         .probe  = da9062_thermal_probe,
 288         .remove = da9062_thermal_remove,
 289         .driver = {
 290                 .name   = "da9062-thermal",
 291                 .of_match_table = da9062_compatible_reg_id_table,
 292         },
 293 };
 294
 295 module_platform_driver(da9062_thermal_driver);
 296
 297 MODULE_AUTHOR("Steve Twiss");
 298 MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
 299 MODULE_LICENSE("GPL");
 300 MODULE_ALIAS("platform:da9062-thermal");