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_zone_device_priv(thermal);
  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                 return -EIO;
  96
  97         /*
  98          * Calculate temperature. According to Marvell internal
  99          * documentation the formula for this is:
 100          * Celsius = (322-reg)/1.3625
 101          */
 102         reg = readl_relaxed(priv->sensor);
 103         reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK;
 104         *temp = ((3220000000UL - (10000000UL * reg)) / 13625);
 105
 106         return 0;
 107 }
 108
 109 static struct thermal_zone_device_ops ops = {
 110         .get_temp = dove_get_temp,
 111 };
 112
 113 static const struct of_device_id dove_thermal_id_table[] = {
 114         { .compatible = "marvell,dove-thermal" },
 115         {}
 116 };
 117
 118 static int dove_thermal_probe(struct platform_device *pdev)
 119 {
 120         struct thermal_zone_device *thermal = NULL;
 121         struct dove_thermal_priv *priv;
 122         int ret;
 123
 124         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 125         if (!priv)
 126                 return -ENOMEM;
 127
 128         priv->sensor = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
 129         if (IS_ERR(priv->sensor))
 130                 return PTR_ERR(priv->sensor);
 131
 132         priv->control = devm_platform_get_and_ioremap_resource(pdev, 1, NULL);
 133         if (IS_ERR(priv->control))
 134                 return PTR_ERR(priv->control);
 135
 136         ret = dove_init_sensor(priv);
 137         if (ret) {
 138                 dev_err(&pdev->dev, "Failed to initialize sensor\n");
 139                 return ret;
 140         }
 141
 142         thermal = thermal_tripless_zone_device_register("dove_thermal", priv,
 143                                                         &ops, NULL);
 144         if (IS_ERR(thermal)) {
 145                 dev_err(&pdev->dev,
 146                         "Failed to register thermal zone device\n");
 147                 return PTR_ERR(thermal);
 148         }
 149
 150         ret = thermal_zone_device_enable(thermal);
 151         if (ret) {
 152                 thermal_zone_device_unregister(thermal);
 153                 return ret;
 154         }
 155
 156         platform_set_drvdata(pdev, thermal);
 157
 158         return 0;
 159 }
 160
 161 static void 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
 169 MODULE_DEVICE_TABLE(of, dove_thermal_id_table);
 170
 171 static struct platform_driver dove_thermal_driver = {
 172         .probe = dove_thermal_probe,
 173         .remove_new = dove_thermal_exit,
 174         .driver = {
 175                 .name = "dove_thermal",
 176                 .of_match_table = dove_thermal_id_table,
 177         },
 178 };
 179
 180 module_platform_driver(dove_thermal_driver);
 181
 182 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
 183 MODULE_DESCRIPTION("Dove thermal driver");
 184 MODULE_LICENSE("GPL");