root/drivers/thermal/dove_thermal.c

DEFINITIONS

1. dove_init_sensor
2. dove_get_temp
3. dove_thermal_probe
4. dove_thermal_exit

   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         struct resource *res;
 126         int ret;
 127 
 128         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 129         if (!priv)
 130                 return -ENOMEM;
 131 
 132         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 133         priv->sensor = devm_ioremap_resource(&pdev->dev, res);
 134         if (IS_ERR(priv->sensor))
 135                 return PTR_ERR(priv->sensor);
 136 
 137         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 138         priv->control = devm_ioremap_resource(&pdev->dev, res);
 139         if (IS_ERR(priv->control))
 140                 return PTR_ERR(priv->control);
 141 
 142         ret = dove_init_sensor(priv);
 143         if (ret) {
 144                 dev_err(&pdev->dev, "Failed to initialize sensor\n");
 145                 return ret;
 146         }
 147 
 148         thermal = thermal_zone_device_register("dove_thermal", 0, 0,
 149                                                priv, &ops, NULL, 0, 0);
 150         if (IS_ERR(thermal)) {
 151                 dev_err(&pdev->dev,
 152                         "Failed to register thermal zone device\n");
 153                 return PTR_ERR(thermal);
 154         }
 155 
 156         platform_set_drvdata(pdev, thermal);
 157 
 158         return 0;
 159 }
 160 
 161 static int dove_thermal_exit(struct platform_device *pdev)
 162 {
 163         struct thermal_zone_device *dove_thermal =
 164                 platform_get_drvdata(pdev);
 165 
 166         thermal_zone_device_unregister(dove_thermal);
 167 
 168         return 0;
 169 }
 170 
 171 MODULE_DEVICE_TABLE(of, dove_thermal_id_table);
 172 
 173 static struct platform_driver dove_thermal_driver = {
 174         .probe = dove_thermal_probe,
 175         .remove = dove_thermal_exit,
 176         .driver = {
 177                 .name = "dove_thermal",
 178                 .of_match_table = dove_thermal_id_table,
 179         },
 180 };
 181 
 182 module_platform_driver(dove_thermal_driver);
 183 
 184 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
 185 MODULE_DESCRIPTION("Dove thermal driver");
 186 MODULE_LICENSE("GPL");