drivers/thermal/da9062-thermal.c

   1 /*
   2  * Thermal device driver for DA9062 and DA9061
   3  * Copyright (C) 2017  Dialog Semiconductor
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 /* When over-temperature is reached, an interrupt from the device will be
  17  * triggered. Following this event the interrupt will be disabled and
  18  * periodic transmission of uevents (HOT trip point) should define the
  19  * first level of temperature supervision. It is expected that any final
  20  * implementation of the thermal driver will include a .notify() function
  21  * to implement these uevents to userspace.
  22  *
  23  * These uevents are intended to indicate non-invasive temperature control
  24  * of the system, where the necessary measures for cooling are the
  25  * responsibility of the host software. Once the temperature falls again,
  26  * the IRQ is re-enabled so the start of a new over-temperature event can
  27  * be detected without constant software monitoring.
  28  */
  29
  30 #include <linux/errno.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/module.h>
  33 #include <linux/of.h>
  34 #include <linux/platform_device.h>
  35 #include <linux/regmap.h>
  36 #include <linux/thermal.h>
  37 #include <linux/workqueue.h>
  38
  39 #include <linux/mfd/da9062/core.h>
  40 #include <linux/mfd/da9062/registers.h>
  41
  42 /* Minimum, maximum and default polling millisecond periods are provided
  43  * here as an example. It is expected that any final implementation to also
  44  * include a modification of these settings to match the required
  45  * application.
  46  */
  47 #define DA9062_DEFAULT_POLLING_MS_PERIOD        3000
  48 #define DA9062_MAX_POLLING_MS_PERIOD            10000
  49 #define DA9062_MIN_POLLING_MS_PERIOD            1000
  50
  51 #define DA9062_MILLI_CELSIUS(t)                 ((t) * 1000)
  52
  53 struct da9062_thermal_config {
  54         const char *name;
  55 };
  56
  57 struct da9062_thermal {
  58         struct da9062 *hw;
  59         struct delayed_work work;
  60         struct thermal_zone_device *zone;
  61         enum thermal_device_mode mode;
  62         struct mutex lock; /* protection for da9062_thermal temperature */
  63         int temperature;
  64         int irq;
  65         const struct da9062_thermal_config *config;
  66         struct device *dev;
  67 };
  68
  69 static void da9062_thermal_poll_on(struct work_struct *work)
  70 {
  71         struct da9062_thermal *thermal = container_of(work,
  72                                                 struct da9062_thermal,
  73                                                 work.work);
  74         unsigned long delay;
  75         unsigned int val;
  76         int ret;
  77
  78         /* clear E_TEMP */
  79         ret = regmap_write(thermal->hw->regmap,
  80                            DA9062AA_EVENT_B,
  81                            DA9062AA_E_TEMP_MASK);
  82         if (ret < 0) {
  83                 dev_err(thermal->dev,
  84                         "Cannot clear the TJUNC temperature status\n");
  85                 goto err_enable_irq;
  86         }
  87
  88         /* Now read E_TEMP again: it is acting like a status bit.
  89          * If over-temperature, then this status will be true.
  90          * If not over-temperature, this status will be false.
  91          */
  92         ret = regmap_read(thermal->hw->regmap,
  93                           DA9062AA_EVENT_B,
  94                           &val);
  95         if (ret < 0) {
  96                 dev_err(thermal->dev,
  97                         "Cannot check the TJUNC temperature status\n");
  98                 goto err_enable_irq;
  99         }
 100
 101         if (val & DA9062AA_E_TEMP_MASK) {
 102                 mutex_lock(&thermal->lock);
 103                 thermal->temperature = DA9062_MILLI_CELSIUS(125);
 104                 mutex_unlock(&thermal->lock);
 105                 thermal_zone_device_update(thermal->zone,
 106                                            THERMAL_EVENT_UNSPECIFIED);
 107
 108                 delay = msecs_to_jiffies(thermal->zone->passive_delay);
 109                 queue_delayed_work(system_freezable_wq, &thermal->work, delay);
 110                 return;
 111         }
 112
 113         mutex_lock(&thermal->lock);
 114         thermal->temperature = DA9062_MILLI_CELSIUS(0);
 115         mutex_unlock(&thermal->lock);
 116         thermal_zone_device_update(thermal->zone,
 117                                    THERMAL_EVENT_UNSPECIFIED);
 118
 119 err_enable_irq:
 120         enable_irq(thermal->irq);
 121 }
 122
 123 static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
 124 {
 125         struct da9062_thermal *thermal = data;
 126
 127         disable_irq_nosync(thermal->irq);
 128         queue_delayed_work(system_freezable_wq, &thermal->work, 0);
 129
 130         return IRQ_HANDLED;
 131 }
 132
 133 static int da9062_thermal_get_mode(struct thermal_zone_device *z,
 134                                    enum thermal_device_mode *mode)
 135 {
 136         struct da9062_thermal *thermal = z->devdata;
 137         *mode = thermal->mode;
 138         return 0;
 139 }
 140
 141 static int da9062_thermal_get_trip_type(struct thermal_zone_device *z,
 142                                         int trip,
 143                                         enum thermal_trip_type *type)
 144 {
 145         struct da9062_thermal *thermal = z->devdata;
 146
 147         switch (trip) {
 148         case 0:
 149                 *type = THERMAL_TRIP_HOT;
 150                 break;
 151         default:
 152                 dev_err(thermal->dev,
 153                         "Driver does not support more than 1 trip-wire\n");
 154                 return -EINVAL;
 155         }
 156
 157         return 0;
 158 }
 159
 160 static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z,
 161                                         int trip,
 162                                         int *temp)
 163 {
 164         struct da9062_thermal *thermal = z->devdata;
 165
 166         switch (trip) {
 167         case 0:
 168                 *temp = DA9062_MILLI_CELSIUS(125);
 169                 break;
 170         default:
 171                 dev_err(thermal->dev,
 172                         "Driver does not support more than 1 trip-wire\n");
 173                 return -EINVAL;
 174         }
 175
 176         return 0;
 177 }
 178
 179 static int da9062_thermal_get_temp(struct thermal_zone_device *z,
 180                                    int *temp)
 181 {
 182         struct da9062_thermal *thermal = z->devdata;
 183
 184         mutex_lock(&thermal->lock);
 185         *temp = thermal->temperature;
 186         mutex_unlock(&thermal->lock);
 187
 188         return 0;
 189 }
 190
 191 static struct thermal_zone_device_ops da9062_thermal_ops = {
 192         .get_temp       = da9062_thermal_get_temp,
 193         .get_mode       = da9062_thermal_get_mode,
 194         .get_trip_type  = da9062_thermal_get_trip_type,
 195         .get_trip_temp  = da9062_thermal_get_trip_temp,
 196 };
 197
 198 static const struct da9062_thermal_config da9062_config = {
 199         .name = "da9062-thermal",
 200 };
 201
 202 static const struct of_device_id da9062_compatible_reg_id_table[] = {
 203         { .compatible = "dlg,da9062-thermal", .data = &da9062_config },
 204         { },
 205 };
 206
 207 MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
 208
 209 static int da9062_thermal_probe(struct platform_device *pdev)
 210 {
 211         struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
 212         struct da9062_thermal *thermal;
 213         unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
 214         const struct of_device_id *match;
 215         int ret = 0;
 216
 217         match = of_match_node(da9062_compatible_reg_id_table,
 218                               pdev->dev.of_node);
 219         if (!match)
 220                 return -ENXIO;
 221
 222         if (pdev->dev.of_node) {
 223                 if (!of_property_read_u32(pdev->dev.of_node,
 224                                           "polling-delay-passive",
 225                                           &pp_tmp)) {
 226                         if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
 227                             pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
 228                                 dev_warn(&pdev->dev,
 229                                          "Out-of-range polling period %d ms\n",
 230                                          pp_tmp);
 231                                 pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
 232                         }
 233                 }
 234         }
 235
 236         thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
 237                                GFP_KERNEL);
 238         if (!thermal) {
 239                 ret = -ENOMEM;
 240                 goto err;
 241         }
 242
 243         thermal->config = match->data;
 244         thermal->hw = chip;
 245         thermal->mode = THERMAL_DEVICE_ENABLED;
 246         thermal->dev = &pdev->dev;
 247
 248         INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
 249         mutex_init(&thermal->lock);
 250
 251         thermal->zone = thermal_zone_device_register(thermal->config->name,
 252                                         1, 0, thermal,
 253                                         &da9062_thermal_ops, NULL, pp_tmp,
 254                                         0);
 255         if (IS_ERR(thermal->zone)) {
 256                 dev_err(&pdev->dev, "Cannot register thermal zone device\n");
 257                 ret = PTR_ERR(thermal->zone);
 258                 goto err;
 259         }
 260
 261         dev_dbg(&pdev->dev,
 262                 "TJUNC temperature polling period set at %d ms\n",
 263                 thermal->zone->passive_delay);
 264
 265         ret = platform_get_irq_byname(pdev, "THERMAL");
 266         if (ret < 0) {
 267                 dev_err(&pdev->dev, "Failed to get platform IRQ.\n");
 268                 goto err_zone;
 269         }
 270         thermal->irq = ret;
 271
 272         ret = request_threaded_irq(thermal->irq, NULL,
 273                                    da9062_thermal_irq_handler,
 274                                    IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 275                                    "THERMAL", thermal);
 276         if (ret) {
 277                 dev_err(&pdev->dev,
 278                         "Failed to request thermal device IRQ.\n");
 279                 goto err_zone;
 280         }
 281
 282         platform_set_drvdata(pdev, thermal);
 283         return 0;
 284
 285 err_zone:
 286         thermal_zone_device_unregister(thermal->zone);
 287 err:
 288         return ret;
 289 }
 290
 291 static int da9062_thermal_remove(struct platform_device *pdev)
 292 {
 293         struct  da9062_thermal *thermal = platform_get_drvdata(pdev);
 294
 295         free_irq(thermal->irq, thermal);
 296         cancel_delayed_work_sync(&thermal->work);
 297         thermal_zone_device_unregister(thermal->zone);
 298         return 0;
 299 }
 300
 301 static struct platform_driver da9062_thermal_driver = {
 302         .probe  = da9062_thermal_probe,
 303         .remove = da9062_thermal_remove,
 304         .driver = {
 305                 .name   = "da9062-thermal",
 306                 .of_match_table = da9062_compatible_reg_id_table,
 307         },
 308 };
 309
 310 module_platform_driver(da9062_thermal_driver);
 311
 312 MODULE_AUTHOR("Steve Twiss");
 313 MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
 314 MODULE_LICENSE("GPL");
 315 MODULE_ALIAS("platform:da9062-thermal");