drivers/thermal/dove_thermal.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Dove thermal sensor driver
   4  *
   5  * Copyright (C) 2013 Andrew Lunn <andrew@lunn.ch>
   6  */
   7 #include <linux/device.h>
   8 #include <linux/err.h>
   9 #include <linux/io.h>
  10 #include <linux/kernel.h>
  11 #include <linux/of.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/thermal.h>
  15
  16 #define DOVE_THERMAL_TEMP_OFFSET        1
  17 #define DOVE_THERMAL_TEMP_MASK          0x1FF
  18
  19 /* Dove Thermal Manager Control and Status Register */
  20 #define PMU_TM_DISABLE_OFFS             0
  21 #define PMU_TM_DISABLE_MASK             (0x1 << PMU_TM_DISABLE_OFFS)
  22
  23 /* Dove Theraml Diode Control 0 Register */
  24 #define PMU_TDC0_SW_RST_MASK            (0x1 << 1)
  25 #define PMU_TDC0_SEL_VCAL_OFFS          5
  26 #define PMU_TDC0_SEL_VCAL_MASK          (0x3 << PMU_TDC0_SEL_VCAL_OFFS)
  27 #define PMU_TDC0_REF_CAL_CNT_OFFS       11
  28 #define PMU_TDC0_REF_CAL_CNT_MASK       (0x1FF << PMU_TDC0_REF_CAL_CNT_OFFS)
  29 #define PMU_TDC0_AVG_NUM_OFFS           25
  30 #define PMU_TDC0_AVG_NUM_MASK           (0x7 << PMU_TDC0_AVG_NUM_OFFS)
  31
  32 /* Dove Thermal Diode Control 1 Register */
  33 #define PMU_TEMP_DIOD_CTRL1_REG         0x04
  34 #define PMU_TDC1_TEMP_VALID_MASK        (0x1 << 10)
  35
  36 /* Dove Thermal Sensor Dev Structure */
  37 struct dove_thermal_priv {
  38         void __iomem *sensor;
  39         void __iomem *control;
  40 };
  41
  42 static int dove_init_sensor(const struct dove_thermal_priv *priv)
  43 {
  44         u32 reg;
  45         u32 i;
  46
  47         /* Configure the Diode Control Register #0 */
  48         reg = readl_relaxed(priv->control);
  49
  50         /* Use average of 2 */
  51         reg &= ~PMU_TDC0_AVG_NUM_MASK;
  52         reg |= (0x1 << PMU_TDC0_AVG_NUM_OFFS);
  53
  54         /* Reference calibration value */
  55         reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
  56         reg |= (0x0F1 << PMU_TDC0_REF_CAL_CNT_OFFS);
  57
  58         /* Set the high level reference for calibration */
  59         reg &= ~PMU_TDC0_SEL_VCAL_MASK;
  60         reg |= (0x2 << PMU_TDC0_SEL_VCAL_OFFS);
  61         writel(reg, priv->control);
  62
  63         /* Reset the sensor */
  64         reg = readl_relaxed(priv->control);
  65         writel((reg | PMU_TDC0_SW_RST_MASK), priv->control);
  66         writel(reg, priv->control);
  67
  68         /* Enable the sensor */
  69         reg = readl_relaxed(priv->sensor);
  70         reg &= ~PMU_TM_DISABLE_MASK;
  71         writel(reg, priv->sensor);
  72
  73         /* Poll the sensor for the first reading */
  74         for (i = 0; i < 1000000; i++) {
  75                 reg = readl_relaxed(priv->sensor);
  76                 if (reg & DOVE_THERMAL_TEMP_MASK)
  77                         break;
  78         }
  79
  80         if (i == 1000000)
  81                 return -EIO;
  82
  83         return 0;
  84 }
  85
  86 static int dove_get_temp(struct thermal_zone_device *thermal,
  87                           int *temp)
  88 {
  89         unsigned long reg;
  90         struct dove_thermal_priv *priv = thermal->devdata;
  91
  92         /* Valid check */
  93         reg = readl_relaxed(priv->control + PMU_TEMP_DIOD_CTRL1_REG);
  94         if ((reg & PMU_TDC1_TEMP_VALID_MASK) == 0x0) {
  95                 dev_err(&thermal->device,
  96                         "Temperature sensor reading not valid\n");
  97                 return -EIO;
  98         }
  99
 100         /*
 101          * Calculate temperature. According to Marvell internal
 102          * documentation the formula for this is:
 103          * Celsius = (322-reg)/1.3625
 104          */
 105         reg = readl_relaxed(priv->sensor);
 106         reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK;
 107         *temp = ((3220000000UL - (10000000UL * reg)) / 13625);
 108
 109         return 0;
 110 }
 111
 112 static struct thermal_zone_device_ops ops = {
 113         .get_temp = dove_get_temp,
 114 };
 115
 116 static const struct of_device_id dove_thermal_id_table[] = {
 117         { .compatible = "marvell,dove-thermal" },
 118         {}
 119 };
 120
 121 static int dove_thermal_probe(struct platform_device *pdev)
 122 {
 123         struct thermal_zone_device *thermal = NULL;
 124         struct dove_thermal_priv *priv;
 125         int ret;
 126
 127         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 128         if (!priv)
 129                 return -ENOMEM;
 130
 131         priv->sensor = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
 132         if (IS_ERR(priv->sensor))
 133                 return PTR_ERR(priv->sensor);
 134
 135         priv->control = devm_platform_get_and_ioremap_resource(pdev, 1, NULL);
 136         if (IS_ERR(priv->control))
 137                 return PTR_ERR(priv->control);
 138
 139         ret = dove_init_sensor(priv);
 140         if (ret) {
 141                 dev_err(&pdev->dev, "Failed to initialize sensor\n");
 142                 return ret;
 143         }
 144
 145         thermal = thermal_zone_device_register("dove_thermal", 0, 0,
 146                                                priv, &ops, NULL, 0, 0);
 147         if (IS_ERR(thermal)) {
 148                 dev_err(&pdev->dev,
 149                         "Failed to register thermal zone device\n");
 150                 return PTR_ERR(thermal);
 151         }
 152
 153         ret = thermal_zone_device_enable(thermal);
 154         if (ret) {
 155                 thermal_zone_device_unregister(thermal);
 156                 return ret;
 157         }
 158
 159         platform_set_drvdata(pdev, thermal);
 160
 161         return 0;
 162 }
 163
 164 static int dove_thermal_exit(struct platform_device *pdev)
 165 {
 166         struct thermal_zone_device *dove_thermal =
 167                 platform_get_drvdata(pdev);
 168
 169         thermal_zone_device_unregister(dove_thermal);
 170
 171         return 0;
 172 }
 173
 174 MODULE_DEVICE_TABLE(of, dove_thermal_id_table);
 175
 176 static struct platform_driver dove_thermal_driver = {
 177         .probe = dove_thermal_probe,
 178         .remove = dove_thermal_exit,
 179         .driver = {
 180                 .name = "dove_thermal",
 181                 .of_match_table = dove_thermal_id_table,
 182         },
 183 };
 184
 185 module_platform_driver(dove_thermal_driver);
 186
 187 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
 188 MODULE_DESCRIPTION("Dove thermal driver");
 189 MODULE_LICENSE("GPL");