root/drivers/thermal/max77620_thermal.c

DEFINITIONS

1. max77620_thermal_read_temp
2. max77620_thermal_irq
3. max77620_thermal_probe

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Junction temperature thermal driver for Maxim Max77620.
   4  *
   5  * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
   6  *
   7  * Author: Laxman Dewangan <ldewangan@nvidia.com>
   8  *         Mallikarjun Kasoju <mkasoju@nvidia.com>
   9  */
  10 
  11 #include <linux/irq.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/mfd/max77620.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/regmap.h>
  18 #include <linux/slab.h>
  19 #include <linux/thermal.h>
  20 
  21 #define MAX77620_NORMAL_OPERATING_TEMP  100000
  22 #define MAX77620_TJALARM1_TEMP          120000
  23 #define MAX77620_TJALARM2_TEMP          140000
  24 
  25 struct max77620_therm_info {
  26         struct device                   *dev;
  27         struct regmap                   *rmap;
  28         struct thermal_zone_device      *tz_device;
  29         int                             irq_tjalarm1;
  30         int                             irq_tjalarm2;
  31 };
  32 
  33 /**
  34  * max77620_thermal_read_temp: Read PMIC die temperatue.
  35  * @data:       Device specific data.
  36  * temp:        Temperature in millidegrees Celsius
  37  *
  38  * The actual temperature of PMIC die is not available from PMIC.
  39  * PMIC only tells the status if it has crossed or not the threshold level
  40  * of 120degC or 140degC.
  41  * If threshold has not been crossed then assume die temperature as 100degC
  42  * else 120degC or 140deG based on the PMIC die temp threshold status.
  43  *
  44  * Return 0 on success otherwise error number to show reason of failure.
  45  */
  46 
  47 static int max77620_thermal_read_temp(void *data, int *temp)
  48 {
  49         struct max77620_therm_info *mtherm = data;
  50         unsigned int val;
  51         int ret;
  52 
  53         ret = regmap_read(mtherm->rmap, MAX77620_REG_STATLBT, &val);
  54         if (ret < 0) {
  55                 dev_err(mtherm->dev, "Failed to read STATLBT: %d\n", ret);
  56                 return ret;
  57         }
  58 
  59         if (val & MAX77620_IRQ_TJALRM2_MASK)
  60                 *temp = MAX77620_TJALARM2_TEMP;
  61         else if (val & MAX77620_IRQ_TJALRM1_MASK)
  62                 *temp = MAX77620_TJALARM1_TEMP;
  63         else
  64                 *temp = MAX77620_NORMAL_OPERATING_TEMP;
  65 
  66         return 0;
  67 }
  68 
  69 static const struct thermal_zone_of_device_ops max77620_thermal_ops = {
  70         .get_temp = max77620_thermal_read_temp,
  71 };
  72 
  73 static irqreturn_t max77620_thermal_irq(int irq, void *data)
  74 {
  75         struct max77620_therm_info *mtherm = data;
  76 
  77         if (irq == mtherm->irq_tjalarm1)
  78                 dev_warn(mtherm->dev, "Junction Temp Alarm1(120C) occurred\n");
  79         else if (irq == mtherm->irq_tjalarm2)
  80                 dev_crit(mtherm->dev, "Junction Temp Alarm2(140C) occurred\n");
  81 
  82         thermal_zone_device_update(mtherm->tz_device,
  83                                    THERMAL_EVENT_UNSPECIFIED);
  84 
  85         return IRQ_HANDLED;
  86 }
  87 
  88 static int max77620_thermal_probe(struct platform_device *pdev)
  89 {
  90         struct max77620_therm_info *mtherm;
  91         int ret;
  92 
  93         mtherm = devm_kzalloc(&pdev->dev, sizeof(*mtherm), GFP_KERNEL);
  94         if (!mtherm)
  95                 return -ENOMEM;
  96 
  97         mtherm->irq_tjalarm1 = platform_get_irq(pdev, 0);
  98         mtherm->irq_tjalarm2 = platform_get_irq(pdev, 1);
  99         if ((mtherm->irq_tjalarm1 < 0) || (mtherm->irq_tjalarm2 < 0)) {
 100                 dev_err(&pdev->dev, "Alarm irq number not available\n");
 101                 return -EINVAL;
 102         }
 103 
 104         mtherm->dev = &pdev->dev;
 105         mtherm->rmap = dev_get_regmap(pdev->dev.parent, NULL);
 106         if (!mtherm->rmap) {
 107                 dev_err(&pdev->dev, "Failed to get parent regmap\n");
 108                 return -ENODEV;
 109         }
 110 
 111         /*
 112          * The reference taken to the parent's node which will be balanced on
 113          * reprobe or on platform-device release.
 114          */
 115         device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent);
 116 
 117         mtherm->tz_device = devm_thermal_zone_of_sensor_register(&pdev->dev, 0,
 118                                 mtherm, &max77620_thermal_ops);
 119         if (IS_ERR(mtherm->tz_device)) {
 120                 ret = PTR_ERR(mtherm->tz_device);
 121                 dev_err(&pdev->dev, "Failed to register thermal zone: %d\n",
 122                         ret);
 123                 return ret;
 124         }
 125 
 126         ret = devm_request_threaded_irq(&pdev->dev, mtherm->irq_tjalarm1, NULL,
 127                                         max77620_thermal_irq,
 128                                         IRQF_ONESHOT | IRQF_SHARED,
 129                                         dev_name(&pdev->dev), mtherm);
 130         if (ret < 0) {
 131                 dev_err(&pdev->dev, "Failed to request irq1: %d\n", ret);
 132                 return ret;
 133         }
 134 
 135         ret = devm_request_threaded_irq(&pdev->dev, mtherm->irq_tjalarm2, NULL,
 136                                         max77620_thermal_irq,
 137                                         IRQF_ONESHOT | IRQF_SHARED,
 138                                         dev_name(&pdev->dev), mtherm);
 139         if (ret < 0) {
 140                 dev_err(&pdev->dev, "Failed to request irq2: %d\n", ret);
 141                 return ret;
 142         }
 143 
 144         platform_set_drvdata(pdev, mtherm);
 145 
 146         return 0;
 147 }
 148 
 149 static struct platform_device_id max77620_thermal_devtype[] = {
 150         { .name = "max77620-thermal", },
 151         {},
 152 };
 153 MODULE_DEVICE_TABLE(platform, max77620_thermal_devtype);
 154 
 155 static struct platform_driver max77620_thermal_driver = {
 156         .driver = {
 157                 .name = "max77620-thermal",
 158         },
 159         .probe = max77620_thermal_probe,
 160         .id_table = max77620_thermal_devtype,
 161 };
 162 
 163 module_platform_driver(max77620_thermal_driver);
 164 
 165 MODULE_DESCRIPTION("Max77620 Junction temperature Thermal driver");
 166 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 167 MODULE_AUTHOR("Mallikarjun Kasoju <mkasoju@nvidia.com>");
 168 MODULE_LICENSE("GPL v2");