drivers/thermal/dove_thermal.c

   1 /*
   2  * Dove thermal sensor driver
   3  *
   4  * Copyright (C) 2013 Andrew Lunn <andrew@lunn.ch>
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  */
  16 #include <linux/device.h>
  17 #include <linux/err.h>
  18 #include <linux/io.h>
  19 #include <linux/kernel.h>
  20 #include <linux/of.h>
  21 #include <linux/module.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/thermal.h>
  24
  25 #define DOVE_THERMAL_TEMP_OFFSET        1
  26 #define DOVE_THERMAL_TEMP_MASK          0x1FF
  27
  28 /* Dove Thermal Manager Control and Status Register */
  29 #define PMU_TM_DISABLE_OFFS             0
  30 #define PMU_TM_DISABLE_MASK             (0x1 << PMU_TM_DISABLE_OFFS)
  31
  32 /* Dove Theraml Diode Control 0 Register */
  33 #define PMU_TDC0_SW_RST_MASK            (0x1 << 1)
  34 #define PMU_TDC0_SEL_VCAL_OFFS          5
  35 #define PMU_TDC0_SEL_VCAL_MASK          (0x3 << PMU_TDC0_SEL_VCAL_OFFS)
  36 #define PMU_TDC0_REF_CAL_CNT_OFFS       11
  37 #define PMU_TDC0_REF_CAL_CNT_MASK       (0x1FF << PMU_TDC0_REF_CAL_CNT_OFFS)
  38 #define PMU_TDC0_AVG_NUM_OFFS           25
  39 #define PMU_TDC0_AVG_NUM_MASK           (0x7 << PMU_TDC0_AVG_NUM_OFFS)
  40
  41 /* Dove Thermal Diode Control 1 Register */
  42 #define PMU_TEMP_DIOD_CTRL1_REG         0x04
  43 #define PMU_TDC1_TEMP_VALID_MASK        (0x1 << 10)
  44
  45 /* Dove Thermal Sensor Dev Structure */
  46 struct dove_thermal_priv {
  47         void __iomem *sensor;
  48         void __iomem *control;
  49 };
  50
  51 static int dove_init_sensor(const struct dove_thermal_priv *priv)
  52 {
  53         u32 reg;
  54         u32 i;
  55
  56         /* Configure the Diode Control Register #0 */
  57         reg = readl_relaxed(priv->control);
  58
  59         /* Use average of 2 */
  60         reg &= ~PMU_TDC0_AVG_NUM_MASK;
  61         reg |= (0x1 << PMU_TDC0_AVG_NUM_OFFS);
  62
  63         /* Reference calibration value */
  64         reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
  65         reg |= (0x0F1 << PMU_TDC0_REF_CAL_CNT_OFFS);
  66
  67         /* Set the high level reference for calibration */
  68         reg &= ~PMU_TDC0_SEL_VCAL_MASK;
  69         reg |= (0x2 << PMU_TDC0_SEL_VCAL_OFFS);
  70         writel(reg, priv->control);
  71
  72         /* Reset the sensor */
  73         reg = readl_relaxed(priv->control);
  74         writel((reg | PMU_TDC0_SW_RST_MASK), priv->control);
  75         writel(reg, priv->control);
  76
  77         /* Enable the sensor */
  78         reg = readl_relaxed(priv->sensor);
  79         reg &= ~PMU_TM_DISABLE_MASK;
  80         writel(reg, priv->sensor);
  81
  82         /* Poll the sensor for the first reading */
  83         for (i = 0; i < 1000000; i++) {
  84                 reg = readl_relaxed(priv->sensor);
  85                 if (reg & DOVE_THERMAL_TEMP_MASK)
  86                         break;
  87         }
  88
  89         if (i == 1000000)
  90                 return -EIO;
  91
  92         return 0;
  93 }
  94
  95 static int dove_get_temp(struct thermal_zone_device *thermal,
  96                           unsigned long *temp)
  97 {
  98         unsigned long reg;
  99         struct dove_thermal_priv *priv = thermal->devdata;
 100
 101         /* Valid check */
 102         reg = readl_relaxed(priv->control + PMU_TEMP_DIOD_CTRL1_REG);
 103         if ((reg & PMU_TDC1_TEMP_VALID_MASK) == 0x0) {
 104                 dev_err(&thermal->device,
 105                         "Temperature sensor reading not valid\n");
 106                 return -EIO;
 107         }
 108
 109         /*
 110          * Calculate temperature. See Section 8.10.1 of 88AP510,
 111          * Documentation/arm/Marvell/README
 112          */
 113         reg = readl_relaxed(priv->sensor);
 114         reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK;
 115         *temp = ((2281638UL - (7298*reg)) / 10);
 116
 117         return 0;
 118 }
 119
 120 static struct thermal_zone_device_ops ops = {
 121         .get_temp = dove_get_temp,
 122 };
 123
 124 static const struct of_device_id dove_thermal_id_table[] = {
 125         { .compatible = "marvell,dove-thermal" },
 126         {}
 127 };
 128
 129 static int dove_thermal_probe(struct platform_device *pdev)
 130 {
 131         struct thermal_zone_device *thermal = NULL;
 132         struct dove_thermal_priv *priv;
 133         struct resource *res;
 134         int ret;
 135
 136         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 137         if (!res) {
 138                 dev_err(&pdev->dev, "Failed to get platform resource\n");
 139                 return -ENODEV;
 140         }
 141
 142         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 143         if (!priv)
 144                 return -ENOMEM;
 145
 146         priv->sensor = devm_ioremap_resource(&pdev->dev, res);
 147         if (IS_ERR(priv->sensor))
 148                 return PTR_ERR(priv->sensor);
 149
 150         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 151         if (!res) {
 152                 dev_err(&pdev->dev, "Failed to get platform resource\n");
 153                 return -ENODEV;
 154         }
 155         priv->control = devm_ioremap_resource(&pdev->dev, res);
 156         if (IS_ERR(priv->control))
 157                 return PTR_ERR(priv->control);
 158
 159         ret = dove_init_sensor(priv);
 160         if (ret) {
 161                 dev_err(&pdev->dev, "Failed to initialize sensor\n");
 162                 return ret;
 163         }
 164
 165         thermal = thermal_zone_device_register("dove_thermal", 0, 0,
 166                                                priv, &ops, NULL, 0, 0);
 167         if (IS_ERR(thermal)) {
 168                 dev_err(&pdev->dev,
 169                         "Failed to register thermal zone device\n");
 170                 return PTR_ERR(thermal);
 171         }
 172
 173         platform_set_drvdata(pdev, thermal);
 174
 175         return 0;
 176 }
 177
 178 static int dove_thermal_exit(struct platform_device *pdev)
 179 {
 180         struct thermal_zone_device *dove_thermal =
 181                 platform_get_drvdata(pdev);
 182
 183         thermal_zone_device_unregister(dove_thermal);
 184         platform_set_drvdata(pdev, NULL);
 185
 186         return 0;
 187 }
 188
 189 MODULE_DEVICE_TABLE(of, dove_thermal_id_table);
 190
 191 static struct platform_driver dove_thermal_driver = {
 192         .probe = dove_thermal_probe,
 193         .remove = dove_thermal_exit,
 194         .driver = {
 195                 .name = "dove_thermal",
 196                 .owner = THIS_MODULE,
 197                 .of_match_table = of_match_ptr(dove_thermal_id_table),
 198         },
 199 };
 200
 201 module_platform_driver(dove_thermal_driver);
 202
 203 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
 204 MODULE_DESCRIPTION("Dove thermal driver");
 205 MODULE_LICENSE("GPL");