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         struct device *dev;
  57         unsigned long interpolated_temp;
  58         unsigned int cur_index;
  59 };
  60
  61 /* Callback to get current temperature */
  62 static int db8500_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
  63 {
  64         struct db8500_thermal_zone *th = thermal_zone_device_priv(tz);
  65
  66         /*
  67          * TODO: There is no PRCMU interface to get temperature data currently,
  68          * so a pseudo temperature is returned , it works for thermal framework
  69          * and this will be fixed when the PRCMU interface is available.
  70          */
  71         *temp = th->interpolated_temp;
  72
  73         return 0;
  74 }
  75
  76 static const struct thermal_zone_device_ops thdev_ops = {
  77         .get_temp = db8500_thermal_get_temp,
  78 };
  79
  80 static void db8500_thermal_update_config(struct db8500_thermal_zone *th,
  81                                          unsigned int idx,
  82                                          unsigned long next_low,
  83                                          unsigned long next_high)
  84 {
  85         prcmu_stop_temp_sense();
  86
  87         th->cur_index = idx;
  88         th->interpolated_temp = (next_low + next_high)/2;
  89
  90         /*
  91          * The PRCMU accept absolute temperatures in celsius so divide
  92          * down the millicelsius with 1000
  93          */
  94         prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000));
  95         prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);
  96 }
  97
  98 static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data)
  99 {
 100         struct db8500_thermal_zone *th = irq_data;
 101         unsigned int idx = th->cur_index;
 102         unsigned long next_low, next_high;
 103
 104         if (idx == 0)
 105                 /* Meaningless for thermal management, ignoring it */
 106                 return IRQ_HANDLED;
 107
 108         if (idx == 1) {
 109                 next_high = db8500_thermal_points[0];
 110                 next_low = PRCMU_DEFAULT_LOW_TEMP;
 111         } else {
 112                 next_high = db8500_thermal_points[idx - 1];
 113                 next_low = db8500_thermal_points[idx - 2];
 114         }
 115         idx -= 1;
 116
 117         db8500_thermal_update_config(th, idx, next_low, next_high);
 118         dev_dbg(th->dev,
 119                 "PRCMU set max %ld, min %ld\n", next_high, next_low);
 120
 121         thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED);
 122
 123         return IRQ_HANDLED;
 124 }
 125
 126 static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data)
 127 {
 128         struct db8500_thermal_zone *th = irq_data;
 129         unsigned int idx = th->cur_index;
 130         unsigned long next_low, next_high;
 131         int num_points = ARRAY_SIZE(db8500_thermal_points);
 132
 133         if (idx < num_points - 1) {
 134                 next_high = db8500_thermal_points[idx+1];
 135                 next_low = db8500_thermal_points[idx];
 136                 idx += 1;
 137
 138                 db8500_thermal_update_config(th, idx, next_low, next_high);
 139
 140                 dev_dbg(th->dev,
 141                         "PRCMU set max %ld, min %ld\n", next_high, next_low);
 142         } else if (idx == num_points - 1)
 143                 /* So we roof out 1 degree over the max point */
 144                 th->interpolated_temp = db8500_thermal_points[idx] + 1;
 145
 146         thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED);
 147
 148         return IRQ_HANDLED;
 149 }
 150
 151 static int db8500_thermal_probe(struct platform_device *pdev)
 152 {
 153         struct db8500_thermal_zone *th = NULL;
 154         struct device *dev = &pdev->dev;
 155         int low_irq, high_irq, ret = 0;
 156
 157         th = devm_kzalloc(dev, sizeof(*th), GFP_KERNEL);
 158         if (!th)
 159                 return -ENOMEM;
 160
 161         th->dev = dev;
 162
 163         low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW");
 164         if (low_irq < 0)
 165                 return low_irq;
 166
 167         ret = devm_request_threaded_irq(dev, low_irq, NULL,
 168                 prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
 169                 "dbx500_temp_low", th);
 170         if (ret < 0) {
 171                 dev_err(dev, "failed to allocate temp low irq\n");
 172                 return ret;
 173         }
 174
 175         high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH");
 176         if (high_irq < 0)
 177                 return high_irq;
 178
 179         ret = devm_request_threaded_irq(dev, high_irq, NULL,
 180                 prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
 181                 "dbx500_temp_high", th);
 182         if (ret < 0) {
 183                 dev_err(dev, "failed to allocate temp high irq\n");
 184                 return ret;
 185         }
 186
 187         /* register of thermal sensor and get info from DT */
 188         th->tz = devm_thermal_of_zone_register(dev, 0, th, &thdev_ops);
 189         if (IS_ERR(th->tz)) {
 190                 dev_err(dev, "register thermal zone sensor failed\n");
 191                 return PTR_ERR(th->tz);
 192         }
 193         dev_info(dev, "thermal zone sensor registered\n");
 194
 195         /* Start measuring at the lowest point */
 196         db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP,
 197                                      db8500_thermal_points[0]);
 198
 199         platform_set_drvdata(pdev, th);
 200
 201         return 0;
 202 }
 203
 204 static int db8500_thermal_suspend(struct platform_device *pdev,
 205                 pm_message_t state)
 206 {
 207         prcmu_stop_temp_sense();
 208
 209         return 0;
 210 }
 211
 212 static int db8500_thermal_resume(struct platform_device *pdev)
 213 {
 214         struct db8500_thermal_zone *th = platform_get_drvdata(pdev);
 215
 216         /* Resume and start measuring at the lowest point */
 217         db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP,
 218                                      db8500_thermal_points[0]);
 219
 220         return 0;
 221 }
 222
 223 static const struct of_device_id db8500_thermal_match[] = {
 224         { .compatible = "stericsson,db8500-thermal" },
 225         {},
 226 };
 227 MODULE_DEVICE_TABLE(of, db8500_thermal_match);
 228
 229 static struct platform_driver db8500_thermal_driver = {
 230         .driver = {
 231                 .name = "db8500-thermal",
 232                 .of_match_table = db8500_thermal_match,
 233         },
 234         .probe = db8500_thermal_probe,
 235         .suspend = db8500_thermal_suspend,
 236         .resume = db8500_thermal_resume,
 237 };
 238
 239 module_platform_driver(db8500_thermal_driver);
 240
 241 MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>");
 242 MODULE_DESCRIPTION("DB8500 thermal driver");
 243 MODULE_LICENSE("GPL");