drivers/thermal/armada_thermal.c

   1 /*
   2  * Marvell Armada 370/XP thermal sensor driver
   3  *
   4  * Copyright (C) 2013 Marvell
   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/delay.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/of_device.h>
  25 #include <linux/thermal.h>
  26
  27 #define THERMAL_VALID_OFFSET            9
  28 #define THERMAL_VALID_MASK              0x1
  29 #define THERMAL_TEMP_OFFSET             10
  30 #define THERMAL_TEMP_MASK               0x1ff
  31
  32 /* Thermal Manager Control and Status Register */
  33 #define PMU_TDC0_SW_RST_MASK            (0x1 << 1)
  34 #define PMU_TM_DISABLE_OFFS             0
  35 #define PMU_TM_DISABLE_MASK             (0x1 << PMU_TM_DISABLE_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_OTF_CAL_MASK           (0x1 << 30)
  39 #define PMU_TDC0_START_CAL_MASK         (0x1 << 25)
  40
  41 struct armada_thermal_ops;
  42
  43 /* Marvell EBU Thermal Sensor Dev Structure */
  44 struct armada_thermal_priv {
  45         void __iomem *sensor;
  46         void __iomem *control;
  47         struct armada_thermal_ops *ops;
  48 };
  49
  50 struct armada_thermal_ops {
  51         /* Initialize the sensor */
  52         void (*init_sensor)(struct armada_thermal_priv *);
  53
  54         /* Test for a valid sensor value (optional) */
  55         bool (*is_valid)(struct armada_thermal_priv *);
  56 };
  57
  58 static void armadaxp_init_sensor(struct armada_thermal_priv *priv)
  59 {
  60         unsigned long reg;
  61
  62         reg = readl_relaxed(priv->control);
  63         reg |= PMU_TDC0_OTF_CAL_MASK;
  64         writel(reg, priv->control);
  65
  66         /* Reference calibration value */
  67         reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
  68         reg |= (0xf1 << PMU_TDC0_REF_CAL_CNT_OFFS);
  69         writel(reg, priv->control);
  70
  71         /* Reset the sensor */
  72         reg = readl_relaxed(priv->control);
  73         writel((reg | PMU_TDC0_SW_RST_MASK), priv->control);
  74
  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
  83 static void armada370_init_sensor(struct armada_thermal_priv *priv)
  84 {
  85         unsigned long reg;
  86
  87         reg = readl_relaxed(priv->control);
  88         reg |= PMU_TDC0_OTF_CAL_MASK;
  89         writel(reg, priv->control);
  90
  91         /* Reference calibration value */
  92         reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
  93         reg |= (0xf1 << PMU_TDC0_REF_CAL_CNT_OFFS);
  94         writel(reg, priv->control);
  95
  96         reg &= ~PMU_TDC0_START_CAL_MASK;
  97         writel(reg, priv->control);
  98
  99         mdelay(10);
 100 }
 101
 102 static bool armada_is_valid(struct armada_thermal_priv *priv)
 103 {
 104         unsigned long reg = readl_relaxed(priv->sensor);
 105
 106         return (reg >> THERMAL_VALID_OFFSET) & THERMAL_VALID_MASK;
 107 }
 108
 109 static int armada_get_temp(struct thermal_zone_device *thermal,
 110                           unsigned long *temp)
 111 {
 112         struct armada_thermal_priv *priv = thermal->devdata;
 113         unsigned long reg;
 114
 115         /* Valid check */
 116         if (priv->ops->is_valid && !priv->ops->is_valid(priv)) {
 117                 dev_err(&thermal->device,
 118                         "Temperature sensor reading not valid\n");
 119                 return -EIO;
 120         }
 121
 122         reg = readl_relaxed(priv->sensor);
 123         reg = (reg >> THERMAL_TEMP_OFFSET) & THERMAL_TEMP_MASK;
 124         *temp = (3153000000UL - (10000000UL*reg)) / 13825;
 125         return 0;
 126 }
 127
 128 static struct thermal_zone_device_ops ops = {
 129         .get_temp = armada_get_temp,
 130 };
 131
 132 static const struct armada_thermal_ops armadaxp_ops = {
 133         .init_sensor = armadaxp_init_sensor,
 134 };
 135
 136 static const struct armada_thermal_ops armada370_ops = {
 137         .is_valid = armada_is_valid,
 138         .init_sensor = armada370_init_sensor,
 139 };
 140
 141 static const struct of_device_id armada_thermal_id_table[] = {
 142         {
 143                 .compatible = "marvell,armadaxp-thermal",
 144                 .data       = &armadaxp_ops,
 145         },
 146         {
 147                 .compatible = "marvell,armada370-thermal",
 148                 .data       = &armada370_ops,
 149         },
 150         {
 151                 /* sentinel */
 152         },
 153 };
 154 MODULE_DEVICE_TABLE(of, armada_thermal_id_table);
 155
 156 static int armada_thermal_probe(struct platform_device *pdev)
 157 {
 158         struct thermal_zone_device *thermal;
 159         const struct of_device_id *match;
 160         struct armada_thermal_priv *priv;
 161         struct resource *res;
 162
 163         match = of_match_device(armada_thermal_id_table, &pdev->dev);
 164         if (!match)
 165                 return -ENODEV;
 166
 167         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 168         if (!priv)
 169                 return -ENOMEM;
 170
 171         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 172         priv->sensor = devm_ioremap_resource(&pdev->dev, res);
 173         if (IS_ERR(priv->sensor))
 174                 return PTR_ERR(priv->sensor);
 175
 176         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 177         priv->control = devm_ioremap_resource(&pdev->dev, res);
 178         if (IS_ERR(priv->control))
 179                 return PTR_ERR(priv->control);
 180
 181         priv->ops = (struct armada_thermal_ops *)match->data;
 182         priv->ops->init_sensor(priv);
 183
 184         thermal = thermal_zone_device_register("armada_thermal", 0, 0,
 185                                                priv, &ops, NULL, 0, 0);
 186         if (IS_ERR(thermal)) {
 187                 dev_err(&pdev->dev,
 188                         "Failed to register thermal zone device\n");
 189                 return PTR_ERR(thermal);
 190         }
 191
 192         platform_set_drvdata(pdev, thermal);
 193
 194         return 0;
 195 }
 196
 197 static int armada_thermal_exit(struct platform_device *pdev)
 198 {
 199         struct thermal_zone_device *armada_thermal =
 200                 platform_get_drvdata(pdev);
 201
 202         thermal_zone_device_unregister(armada_thermal);
 203
 204         return 0;
 205 }
 206
 207 static struct platform_driver armada_thermal_driver = {
 208         .probe = armada_thermal_probe,
 209         .remove = armada_thermal_exit,
 210         .driver = {
 211                 .name = "armada_thermal",
 212                 .owner = THIS_MODULE,
 213                 .of_match_table = armada_thermal_id_table,
 214         },
 215 };
 216
 217 module_platform_driver(armada_thermal_driver);
 218
 219 MODULE_AUTHOR("Ezequiel Garcia <ezequiel.garcia@free-electrons.com>");
 220 MODULE_DESCRIPTION("Armada 370/XP thermal driver");
 221 MODULE_LICENSE("GPL v2");