drivers/thermal/spear_thermal.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * SPEAr thermal driver.
   4  *
   5  * Copyright (C) 2011-2012 ST Microelectronics
   6  * Author: Vincenzo Frascino <vincenzo.frascino@st.com>
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/device.h>
  11 #include <linux/err.h>
  12 #include <linux/io.h>
  13 #include <linux/kernel.h>
  14 #include <linux/of.h>
  15 #include <linux/module.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/thermal.h>
  18
  19 #define MD_FACTOR       1000
  20
  21 /* SPEAr Thermal Sensor Dev Structure */
  22 struct spear_thermal_dev {
  23         /* pointer to base address of the thermal sensor */
  24         void __iomem *thermal_base;
  25         /* clk structure */
  26         struct clk *clk;
  27         /* pointer to thermal flags */
  28         unsigned int flags;
  29 };
  30
  31 static inline int thermal_get_temp(struct thermal_zone_device *thermal,
  32                                 int *temp)
  33 {
  34         struct spear_thermal_dev *stdev = thermal_zone_device_priv(thermal);
  35
  36         /*
  37          * Data are ready to be read after 628 usec from POWERDOWN signal
  38          * (PDN) = 1
  39          */
  40         *temp = (readl_relaxed(stdev->thermal_base) & 0x7F) * MD_FACTOR;
  41         return 0;
  42 }
  43
  44 static struct thermal_zone_device_ops ops = {
  45         .get_temp = thermal_get_temp,
  46 };
  47
  48 static int __maybe_unused spear_thermal_suspend(struct device *dev)
  49 {
  50         struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev);
  51         struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal);
  52         unsigned int actual_mask = 0;
  53
  54         /* Disable SPEAr Thermal Sensor */
  55         actual_mask = readl_relaxed(stdev->thermal_base);
  56         writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
  57
  58         clk_disable(stdev->clk);
  59         dev_info(dev, "Suspended.\n");
  60
  61         return 0;
  62 }
  63
  64 static int __maybe_unused spear_thermal_resume(struct device *dev)
  65 {
  66         struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev);
  67         struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal);
  68         unsigned int actual_mask = 0;
  69         int ret = 0;
  70
  71         ret = clk_enable(stdev->clk);
  72         if (ret) {
  73                 dev_err(dev, "Can't enable clock\n");
  74                 return ret;
  75         }
  76
  77         /* Enable SPEAr Thermal Sensor */
  78         actual_mask = readl_relaxed(stdev->thermal_base);
  79         writel_relaxed(actual_mask | stdev->flags, stdev->thermal_base);
  80
  81         dev_info(dev, "Resumed.\n");
  82
  83         return 0;
  84 }
  85
  86 static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend,
  87                 spear_thermal_resume);
  88
  89 static int spear_thermal_probe(struct platform_device *pdev)
  90 {
  91         struct thermal_zone_device *spear_thermal = NULL;
  92         struct spear_thermal_dev *stdev;
  93         struct device_node *np = pdev->dev.of_node;
  94         int ret = 0, val;
  95
  96         if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) {
  97                 dev_err(&pdev->dev, "Failed: DT Pdata not passed\n");
  98                 return -EINVAL;
  99         }
 100
 101         stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL);
 102         if (!stdev)
 103                 return -ENOMEM;
 104
 105         /* Enable thermal sensor */
 106         stdev->thermal_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
 107         if (IS_ERR(stdev->thermal_base))
 108                 return PTR_ERR(stdev->thermal_base);
 109
 110         stdev->clk = devm_clk_get(&pdev->dev, NULL);
 111         if (IS_ERR(stdev->clk)) {
 112                 dev_err(&pdev->dev, "Can't get clock\n");
 113                 return PTR_ERR(stdev->clk);
 114         }
 115
 116         ret = clk_enable(stdev->clk);
 117         if (ret) {
 118                 dev_err(&pdev->dev, "Can't enable clock\n");
 119                 return ret;
 120         }
 121
 122         stdev->flags = val;
 123         writel_relaxed(stdev->flags, stdev->thermal_base);
 124
 125         spear_thermal = thermal_tripless_zone_device_register("spear_thermal",
 126                                                               stdev, &ops, NULL);
 127         if (IS_ERR(spear_thermal)) {
 128                 dev_err(&pdev->dev, "thermal zone device is NULL\n");
 129                 ret = PTR_ERR(spear_thermal);
 130                 goto disable_clk;
 131         }
 132         ret = thermal_zone_device_enable(spear_thermal);
 133         if (ret) {
 134                 dev_err(&pdev->dev, "Cannot enable thermal zone\n");
 135                 goto unregister_tzd;
 136         }
 137
 138         platform_set_drvdata(pdev, spear_thermal);
 139
 140         dev_info(&pdev->dev, "Thermal Sensor Loaded at: 0x%p.\n",
 141                         stdev->thermal_base);
 142
 143         return 0;
 144
 145 unregister_tzd:
 146         thermal_zone_device_unregister(spear_thermal);
 147 disable_clk:
 148         clk_disable(stdev->clk);
 149
 150         return ret;
 151 }
 152
 153 static void spear_thermal_exit(struct platform_device *pdev)
 154 {
 155         unsigned int actual_mask = 0;
 156         struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
 157         struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal);
 158
 159         thermal_zone_device_unregister(spear_thermal);
 160
 161         /* Disable SPEAr Thermal Sensor */
 162         actual_mask = readl_relaxed(stdev->thermal_base);
 163         writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
 164
 165         clk_disable(stdev->clk);
 166 }
 167
 168 static const struct of_device_id spear_thermal_id_table[] = {
 169         { .compatible = "st,thermal-spear1340" },
 170         {}
 171 };
 172 MODULE_DEVICE_TABLE(of, spear_thermal_id_table);
 173
 174 static struct platform_driver spear_thermal_driver = {
 175         .probe = spear_thermal_probe,
 176         .remove = spear_thermal_exit,
 177         .driver = {
 178                 .name = "spear_thermal",
 179                 .pm = &spear_thermal_pm_ops,
 180                 .of_match_table = spear_thermal_id_table,
 181         },
 182 };
 183
 184 module_platform_driver(spear_thermal_driver);
 185
 186 MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>");
 187 MODULE_DESCRIPTION("SPEAr thermal driver");
 188 MODULE_LICENSE("GPL");