drivers/thermal/db8500_thermal.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * db8500_thermal.c - DB8500 Thermal Management Implementation
   4  *
   5  * Copyright (C) 2012 ST-Ericsson
   6  * Copyright (C) 2012-2019 Linaro Ltd.
   7  *
   8  * Authors: Hongbo Zhang, Linus Walleij
   9  */
  10
  11 #include <linux/cpu_cooling.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/mfd/dbx500-prcmu.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/slab.h>
  18 #include <linux/thermal.h>
  19
  20 #define PRCMU_DEFAULT_MEASURE_TIME      0xFFF
  21 #define PRCMU_DEFAULT_LOW_TEMP          0
  22
  23 /**
  24  * db8500_thermal_points - the interpolation points that trigger
  25  * interrupts
  26  */
  27 static const unsigned long db8500_thermal_points[] = {
  28         15000,
  29         20000,
  30         25000,
  31         30000,
  32         35000,
  33         40000,
  34         45000,
  35         50000,
  36         55000,
  37         60000,
  38         65000,
  39         70000,
  40         75000,
  41         80000,
  42         /*
  43          * This is where things start to get really bad for the
  44          * SoC and the thermal zones should be set up to trigger
  45          * critical temperature at 85000 mC so we don't get above
  46          * this point.
  47          */
  48         85000,
  49         90000,
  50         95000,
  51         100000,
  52 };
  53
  54 struct db8500_thermal_zone {
  55         struct thermal_zone_device *tz;
  56         unsigned long interpolated_temp;
  57         unsigned int cur_index;
  58 };
  59
  60 /* Callback to get current temperature */
  61 static int db8500_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
  62 {
  63         struct db8500_thermal_zone *th = tz->devdata;
  64
  65         /*
  66          * TODO: There is no PRCMU interface to get temperature data currently,
  67          * so a pseudo temperature is returned , it works for thermal framework
  68          * and this will be fixed when the PRCMU interface is available.
  69          */
  70         *temp = th->interpolated_temp;
  71
  72         return 0;
  73 }
  74
  75 static const struct thermal_zone_device_ops thdev_ops = {
  76         .get_temp = db8500_thermal_get_temp,
  77 };
  78
  79 static void db8500_thermal_update_config(struct db8500_thermal_zone *th,
  80                                          unsigned int idx,
  81                                          unsigned long next_low,
  82                                          unsigned long next_high)
  83 {
  84         prcmu_stop_temp_sense();
  85
  86         th->cur_index = idx;
  87         th->interpolated_temp = (next_low + next_high)/2;
  88
  89         /*
  90          * The PRCMU accept absolute temperatures in celsius so divide
  91          * down the millicelsius with 1000
  92          */
  93         prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000));
  94         prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);
  95 }
  96
  97 static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data)
  98 {
  99         struct db8500_thermal_zone *th = irq_data;
 100         unsigned int idx = th->cur_index;
 101         unsigned long next_low, next_high;
 102
 103         if (idx == 0)
 104                 /* Meaningless for thermal management, ignoring it */
 105                 return IRQ_HANDLED;
 106
 107         if (idx == 1) {
 108                 next_high = db8500_thermal_points[0];
 109                 next_low = PRCMU_DEFAULT_LOW_TEMP;
 110         } else {
 111                 next_high = db8500_thermal_points[idx - 1];
 112                 next_low = db8500_thermal_points[idx - 2];
 113         }
 114         idx -= 1;
 115
 116         db8500_thermal_update_config(th, idx, next_low, next_high);
 117         dev_dbg(&th->tz->device,
 118                 "PRCMU set max %ld, min %ld\n", next_high, next_low);
 119
 120         thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED);
 121
 122         return IRQ_HANDLED;
 123 }
 124
 125 static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data)
 126 {
 127         struct db8500_thermal_zone *th = irq_data;
 128         unsigned int idx = th->cur_index;
 129         unsigned long next_low, next_high;
 130         int num_points = ARRAY_SIZE(db8500_thermal_points);
 131
 132         if (idx < num_points - 1) {
 133                 next_high = db8500_thermal_points[idx+1];
 134                 next_low = db8500_thermal_points[idx];
 135                 idx += 1;
 136
 137                 db8500_thermal_update_config(th, idx, next_low, next_high);
 138
 139                 dev_dbg(&th->tz->device,
 140                         "PRCMU set max %ld, min %ld\n", next_high, next_low);
 141         } else if (idx == num_points - 1)
 142                 /* So we roof out 1 degree over the max point */
 143                 th->interpolated_temp = db8500_thermal_points[idx] + 1;
 144
 145         thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED);
 146
 147         return IRQ_HANDLED;
 148 }
 149
 150 static int db8500_thermal_probe(struct platform_device *pdev)
 151 {
 152         struct db8500_thermal_zone *th = NULL;
 153         struct device *dev = &pdev->dev;
 154         int low_irq, high_irq, ret = 0;
 155
 156         th = devm_kzalloc(dev, sizeof(*th), GFP_KERNEL);
 157         if (!th)
 158                 return -ENOMEM;
 159
 160         low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW");
 161         if (low_irq < 0)
 162                 return low_irq;
 163
 164         ret = devm_request_threaded_irq(dev, low_irq, NULL,
 165                 prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
 166                 "dbx500_temp_low", th);
 167         if (ret < 0) {
 168                 dev_err(dev, "failed to allocate temp low irq\n");
 169                 return ret;
 170         }
 171
 172         high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH");
 173         if (high_irq < 0)
 174                 return high_irq;
 175
 176         ret = devm_request_threaded_irq(dev, high_irq, NULL,
 177                 prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
 178                 "dbx500_temp_high", th);
 179         if (ret < 0) {
 180                 dev_err(dev, "failed to allocate temp high irq\n");
 181                 return ret;
 182         }
 183
 184         /* register of thermal sensor and get info from DT */
 185         th->tz = devm_thermal_of_zone_register(dev, 0, th, &thdev_ops);
 186         if (IS_ERR(th->tz)) {
 187                 dev_err(dev, "register thermal zone sensor failed\n");
 188                 return PTR_ERR(th->tz);
 189         }
 190         dev_info(dev, "thermal zone sensor registered\n");
 191
 192         /* Start measuring at the lowest point */
 193         db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP,
 194                                      db8500_thermal_points[0]);
 195
 196         platform_set_drvdata(pdev, th);
 197
 198         return 0;
 199 }
 200
 201 static int db8500_thermal_suspend(struct platform_device *pdev,
 202                 pm_message_t state)
 203 {
 204         prcmu_stop_temp_sense();
 205
 206         return 0;
 207 }
 208
 209 static int db8500_thermal_resume(struct platform_device *pdev)
 210 {
 211         struct db8500_thermal_zone *th = platform_get_drvdata(pdev);
 212
 213         /* Resume and start measuring at the lowest point */
 214         db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP,
 215                                      db8500_thermal_points[0]);
 216
 217         return 0;
 218 }
 219
 220 static const struct of_device_id db8500_thermal_match[] = {
 221         { .compatible = "stericsson,db8500-thermal" },
 222         {},
 223 };
 224 MODULE_DEVICE_TABLE(of, db8500_thermal_match);
 225
 226 static struct platform_driver db8500_thermal_driver = {
 227         .driver = {
 228                 .name = "db8500-thermal",
 229                 .of_match_table = of_match_ptr(db8500_thermal_match),
 230         },
 231         .probe = db8500_thermal_probe,
 232         .suspend = db8500_thermal_suspend,
 233         .resume = db8500_thermal_resume,
 234 };
 235
 236 module_platform_driver(db8500_thermal_driver);
 237
 238 MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
 239 MODULE_DESCRIPTION("DB8500 thermal driver");
 240 MODULE_LICENSE("GPL");