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->devdata;
  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 = spear_thermal->devdata;
  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 = spear_thermal->devdata;
  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         struct resource *res;
  95         int ret = 0, val;
  96
  97         if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) {
  98                 dev_err(&pdev->dev, "Failed: DT Pdata not passed\n");
  99                 return -EINVAL;
 100         }
 101
 102         stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL);
 103         if (!stdev)
 104                 return -ENOMEM;
 105
 106         /* Enable thermal sensor */
 107         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 108         stdev->thermal_base = devm_ioremap_resource(&pdev->dev, res);
 109         if (IS_ERR(stdev->thermal_base))
 110                 return PTR_ERR(stdev->thermal_base);
 111
 112         stdev->clk = devm_clk_get(&pdev->dev, NULL);
 113         if (IS_ERR(stdev->clk)) {
 114                 dev_err(&pdev->dev, "Can't get clock\n");
 115                 return PTR_ERR(stdev->clk);
 116         }
 117
 118         ret = clk_enable(stdev->clk);
 119         if (ret) {
 120                 dev_err(&pdev->dev, "Can't enable clock\n");
 121                 return ret;
 122         }
 123
 124         stdev->flags = val;
 125         writel_relaxed(stdev->flags, stdev->thermal_base);
 126
 127         spear_thermal = thermal_zone_device_register("spear_thermal", 0, 0,
 128                                 stdev, &ops, NULL, 0, 0);
 129         if (IS_ERR(spear_thermal)) {
 130                 dev_err(&pdev->dev, "thermal zone device is NULL\n");
 131                 ret = PTR_ERR(spear_thermal);
 132                 goto disable_clk;
 133         }
 134
 135         platform_set_drvdata(pdev, spear_thermal);
 136
 137         dev_info(&spear_thermal->device, "Thermal Sensor Loaded at: 0x%p.\n",
 138                         stdev->thermal_base);
 139
 140         return 0;
 141
 142 disable_clk:
 143         clk_disable(stdev->clk);
 144
 145         return ret;
 146 }
 147
 148 static int spear_thermal_exit(struct platform_device *pdev)
 149 {
 150         unsigned int actual_mask = 0;
 151         struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
 152         struct spear_thermal_dev *stdev = spear_thermal->devdata;
 153
 154         thermal_zone_device_unregister(spear_thermal);
 155
 156         /* Disable SPEAr Thermal Sensor */
 157         actual_mask = readl_relaxed(stdev->thermal_base);
 158         writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
 159
 160         clk_disable(stdev->clk);
 161
 162         return 0;
 163 }
 164
 165 static const struct of_device_id spear_thermal_id_table[] = {
 166         { .compatible = "st,thermal-spear1340" },
 167         {}
 168 };
 169 MODULE_DEVICE_TABLE(of, spear_thermal_id_table);
 170
 171 static struct platform_driver spear_thermal_driver = {
 172         .probe = spear_thermal_probe,
 173         .remove = spear_thermal_exit,
 174         .driver = {
 175                 .name = "spear_thermal",
 176                 .pm = &spear_thermal_pm_ops,
 177                 .of_match_table = spear_thermal_id_table,
 178         },
 179 };
 180
 181 module_platform_driver(spear_thermal_driver);
 182
 183 MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>");
 184 MODULE_DESCRIPTION("SPEAr thermal driver");
 185 MODULE_LICENSE("GPL");