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 = thermal->zone->passive_delay_jiffies;
  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_temp(struct thermal_zone_device *z,
 124                                    int *temp)
 125 {
 126         struct da9062_thermal *thermal = z->devdata;
 127
 128         mutex_lock(&thermal->lock);
 129         *temp = thermal->temperature;
 130         mutex_unlock(&thermal->lock);
 131
 132         return 0;
 133 }
 134
 135 static struct thermal_zone_device_ops da9062_thermal_ops = {
 136         .get_temp       = da9062_thermal_get_temp,
 137 };
 138
 139 static struct thermal_trip trips[] = {
 140         { .temperature = DA9062_MILLI_CELSIUS(125), .type = THERMAL_TRIP_HOT },
 141 };
 142
 143 static const struct da9062_thermal_config da9062_config = {
 144         .name = "da9062-thermal",
 145 };
 146
 147 static const struct of_device_id da9062_compatible_reg_id_table[] = {
 148         { .compatible = "dlg,da9062-thermal", .data = &da9062_config },
 149         { },
 150 };
 151
 152 MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
 153
 154 static int da9062_thermal_probe(struct platform_device *pdev)
 155 {
 156         struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
 157         struct da9062_thermal *thermal;
 158         unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
 159         const struct of_device_id *match;
 160         int ret = 0;
 161
 162         match = of_match_node(da9062_compatible_reg_id_table,
 163                               pdev->dev.of_node);
 164         if (!match)
 165                 return -ENXIO;
 166
 167         if (pdev->dev.of_node) {
 168                 if (!of_property_read_u32(pdev->dev.of_node,
 169                                           "polling-delay-passive",
 170                                           &pp_tmp)) {
 171                         if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
 172                             pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
 173                                 dev_warn(&pdev->dev,
 174                                          "Out-of-range polling period %d ms\n",
 175                                          pp_tmp);
 176                                 pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
 177                         }
 178                 }
 179         }
 180
 181         thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
 182                                GFP_KERNEL);
 183         if (!thermal) {
 184                 ret = -ENOMEM;
 185                 goto err;
 186         }
 187
 188         thermal->config = match->data;
 189         thermal->hw = chip;
 190         thermal->dev = &pdev->dev;
 191
 192         INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
 193         mutex_init(&thermal->lock);
 194
 195         thermal->zone = thermal_zone_device_register_with_trips(thermal->config->name,
 196                                                                 trips, ARRAY_SIZE(trips), 0, thermal,
 197                                                                 &da9062_thermal_ops, NULL, pp_tmp,
 198                                                                 0);
 199         if (IS_ERR(thermal->zone)) {
 200                 dev_err(&pdev->dev, "Cannot register thermal zone device\n");
 201                 ret = PTR_ERR(thermal->zone);
 202                 goto err;
 203         }
 204         ret = thermal_zone_device_enable(thermal->zone);
 205         if (ret) {
 206                 dev_err(&pdev->dev, "Cannot enable thermal zone device\n");
 207                 goto err_zone;
 208         }
 209
 210         dev_dbg(&pdev->dev,
 211                 "TJUNC temperature polling period set at %d ms\n",
 212                 jiffies_to_msecs(thermal->zone->passive_delay_jiffies));
 213
 214         ret = platform_get_irq_byname(pdev, "THERMAL");
 215         if (ret < 0)
 216                 goto err_zone;
 217
 218         thermal->irq = ret;
 219
 220         ret = request_threaded_irq(thermal->irq, NULL,
 221                                    da9062_thermal_irq_handler,
 222                                    IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 223                                    "THERMAL", thermal);
 224         if (ret) {
 225                 dev_err(&pdev->dev,
 226                         "Failed to request thermal device IRQ.\n");
 227                 goto err_zone;
 228         }
 229
 230         platform_set_drvdata(pdev, thermal);
 231         return 0;
 232
 233 err_zone:
 234         thermal_zone_device_unregister(thermal->zone);
 235 err:
 236         return ret;
 237 }
 238
 239 static int da9062_thermal_remove(struct platform_device *pdev)
 240 {
 241         struct  da9062_thermal *thermal = platform_get_drvdata(pdev);
 242
 243         free_irq(thermal->irq, thermal);
 244         cancel_delayed_work_sync(&thermal->work);
 245         thermal_zone_device_unregister(thermal->zone);
 246         return 0;
 247 }
 248
 249 static struct platform_driver da9062_thermal_driver = {
 250         .probe  = da9062_thermal_probe,
 251         .remove = da9062_thermal_remove,
 252         .driver = {
 253                 .name   = "da9062-thermal",
 254                 .of_match_table = da9062_compatible_reg_id_table,
 255         },
 256 };
 257
 258 module_platform_driver(da9062_thermal_driver);
 259
 260 MODULE_AUTHOR("Steve Twiss");
 261 MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
 262 MODULE_LICENSE("GPL");
 263 MODULE_ALIAS("platform:da9062-thermal");