drivers/thermal/max77620_thermal.c

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