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 static unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
  45
  46 struct da9062_thermal_config {
  47         const char *name;
  48 };
  49
  50 struct da9062_thermal {
  51         struct da9062 *hw;
  52         struct delayed_work work;
  53         struct thermal_zone_device *zone;
  54         struct mutex lock; /* protection for da9062_thermal temperature */
  55         int temperature;
  56         int irq;
  57         const struct da9062_thermal_config *config;
  58         struct device *dev;
  59 };
  60
  61 static void da9062_thermal_poll_on(struct work_struct *work)
  62 {
  63         struct da9062_thermal *thermal = container_of(work,
  64                                                 struct da9062_thermal,
  65                                                 work.work);
  66         unsigned long delay;
  67         unsigned int val;
  68         int ret;
  69
  70         /* clear E_TEMP */
  71         ret = regmap_write(thermal->hw->regmap,
  72                            DA9062AA_EVENT_B,
  73                            DA9062AA_E_TEMP_MASK);
  74         if (ret < 0) {
  75                 dev_err(thermal->dev,
  76                         "Cannot clear the TJUNC temperature status\n");
  77                 goto err_enable_irq;
  78         }
  79
  80         /* Now read E_TEMP again: it is acting like a status bit.
  81          * If over-temperature, then this status will be true.
  82          * If not over-temperature, this status will be false.
  83          */
  84         ret = regmap_read(thermal->hw->regmap,
  85                           DA9062AA_EVENT_B,
  86                           &val);
  87         if (ret < 0) {
  88                 dev_err(thermal->dev,
  89                         "Cannot check the TJUNC temperature status\n");
  90                 goto err_enable_irq;
  91         }
  92
  93         if (val & DA9062AA_E_TEMP_MASK) {
  94                 mutex_lock(&thermal->lock);
  95                 thermal->temperature = DA9062_MILLI_CELSIUS(125);
  96                 mutex_unlock(&thermal->lock);
  97                 thermal_zone_device_update(thermal->zone,
  98                                            THERMAL_EVENT_UNSPECIFIED);
  99
 100                 /*
 101                  * pp_tmp is between 1s and 10s, so we can round the jiffies
 102                  */
 103                 delay = round_jiffies(msecs_to_jiffies(pp_tmp));
 104                 queue_delayed_work(system_freezable_wq, &thermal->work, delay);
 105                 return;
 106         }
 107
 108         mutex_lock(&thermal->lock);
 109         thermal->temperature = DA9062_MILLI_CELSIUS(0);
 110         mutex_unlock(&thermal->lock);
 111         thermal_zone_device_update(thermal->zone,
 112                                    THERMAL_EVENT_UNSPECIFIED);
 113
 114 err_enable_irq:
 115         enable_irq(thermal->irq);
 116 }
 117
 118 static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
 119 {
 120         struct da9062_thermal *thermal = data;
 121
 122         disable_irq_nosync(thermal->irq);
 123         queue_delayed_work(system_freezable_wq, &thermal->work, 0);
 124
 125         return IRQ_HANDLED;
 126 }
 127
 128 static int da9062_thermal_get_temp(struct thermal_zone_device *z,
 129                                    int *temp)
 130 {
 131         struct da9062_thermal *thermal = thermal_zone_device_priv(z);
 132
 133         mutex_lock(&thermal->lock);
 134         *temp = thermal->temperature;
 135         mutex_unlock(&thermal->lock);
 136
 137         return 0;
 138 }
 139
 140 static struct thermal_zone_device_ops da9062_thermal_ops = {
 141         .get_temp       = da9062_thermal_get_temp,
 142 };
 143
 144 static struct thermal_trip trips[] = {
 145         { .temperature = DA9062_MILLI_CELSIUS(125), .type = THERMAL_TRIP_HOT },
 146 };
 147
 148 static const struct da9062_thermal_config da9062_config = {
 149         .name = "da9062-thermal",
 150 };
 151
 152 static const struct of_device_id da9062_compatible_reg_id_table[] = {
 153         { .compatible = "dlg,da9062-thermal", .data = &da9062_config },
 154         { },
 155 };
 156
 157 MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
 158
 159 static int da9062_thermal_probe(struct platform_device *pdev)
 160 {
 161         struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
 162         struct da9062_thermal *thermal;
 163         const struct of_device_id *match;
 164         int ret = 0;
 165
 166         match = of_match_node(da9062_compatible_reg_id_table,
 167                               pdev->dev.of_node);
 168         if (!match)
 169                 return -ENXIO;
 170
 171         if (pdev->dev.of_node) {
 172                 if (!of_property_read_u32(pdev->dev.of_node,
 173                                           "polling-delay-passive",
 174                                           &pp_tmp)) {
 175                         if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
 176                             pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
 177                                 dev_warn(&pdev->dev,
 178                                          "Out-of-range polling period %d ms\n",
 179                                          pp_tmp);
 180                                 pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
 181                         }
 182                 }
 183         }
 184
 185         thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
 186                                GFP_KERNEL);
 187         if (!thermal) {
 188                 ret = -ENOMEM;
 189                 goto err;
 190         }
 191
 192         thermal->config = match->data;
 193         thermal->hw = chip;
 194         thermal->dev = &pdev->dev;
 195
 196         INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
 197         mutex_init(&thermal->lock);
 198
 199         thermal->zone = thermal_zone_device_register_with_trips(thermal->config->name,
 200                                                                 trips, ARRAY_SIZE(trips), 0, thermal,
 201                                                                 &da9062_thermal_ops, NULL, pp_tmp,
 202                                                                 0);
 203         if (IS_ERR(thermal->zone)) {
 204                 dev_err(&pdev->dev, "Cannot register thermal zone device\n");
 205                 ret = PTR_ERR(thermal->zone);
 206                 goto err;
 207         }
 208         ret = thermal_zone_device_enable(thermal->zone);
 209         if (ret) {
 210                 dev_err(&pdev->dev, "Cannot enable thermal zone device\n");
 211                 goto err_zone;
 212         }
 213
 214         dev_dbg(&pdev->dev,
 215                 "TJUNC temperature polling period set at %d ms\n", pp_tmp);
 216
 217         ret = platform_get_irq_byname(pdev, "THERMAL");
 218         if (ret < 0)
 219                 goto err_zone;
 220
 221         thermal->irq = ret;
 222
 223         ret = request_threaded_irq(thermal->irq, NULL,
 224                                    da9062_thermal_irq_handler,
 225                                    IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 226                                    "THERMAL", thermal);
 227         if (ret) {
 228                 dev_err(&pdev->dev,
 229                         "Failed to request thermal device IRQ.\n");
 230                 goto err_zone;
 231         }
 232
 233         platform_set_drvdata(pdev, thermal);
 234         return 0;
 235
 236 err_zone:
 237         thermal_zone_device_unregister(thermal->zone);
 238 err:
 239         return ret;
 240 }
 241
 242 static int da9062_thermal_remove(struct platform_device *pdev)
 243 {
 244         struct  da9062_thermal *thermal = platform_get_drvdata(pdev);
 245
 246         free_irq(thermal->irq, thermal);
 247         cancel_delayed_work_sync(&thermal->work);
 248         thermal_zone_device_unregister(thermal->zone);
 249         return 0;
 250 }
 251
 252 static struct platform_driver da9062_thermal_driver = {
 253         .probe  = da9062_thermal_probe,
 254         .remove = da9062_thermal_remove,
 255         .driver = {
 256                 .name   = "da9062-thermal",
 257                 .of_match_table = da9062_compatible_reg_id_table,
 258         },
 259 };
 260
 261 module_platform_driver(da9062_thermal_driver);
 262
 263 MODULE_AUTHOR("Steve Twiss");
 264 MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
 265 MODULE_LICENSE("GPL");
 266 MODULE_ALIAS("platform:da9062-thermal");