broadcom/ns-thermal.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2017 Rafał Miłecki <rafal@milecki.pl>
   4  */
   5
   6 #include <linux/module.h>
   7 #include <linux/of_address.h>
   8 #include <linux/platform_device.h>
   9 #include <linux/thermal.h>
  10
  11 #define PVTMON_CONTROL0                                 0x00
  12 #define PVTMON_CONTROL0_SEL_MASK                        0x0000000e
  13 #define PVTMON_CONTROL0_SEL_TEMP_MONITOR                0x00000000
  14 #define PVTMON_CONTROL0_SEL_TEST_MODE                   0x0000000e
  15 #define PVTMON_STATUS                                   0x08
  16
  17 static int ns_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
  18 {
  19         void __iomem *pvtmon = thermal_zone_device_priv(tz);
  20         int offset = thermal_zone_get_offset(tz);
  21         int slope = thermal_zone_get_slope(tz);
  22         u32 val;
  23
  24         val = readl(pvtmon + PVTMON_CONTROL0);
  25         if ((val & PVTMON_CONTROL0_SEL_MASK) != PVTMON_CONTROL0_SEL_TEMP_MONITOR) {
  26                 /* Clear current mode selection */
  27                 val &= ~PVTMON_CONTROL0_SEL_MASK;
  28
  29                 /* Set temp monitor mode (it's the default actually) */
  30                 val |= PVTMON_CONTROL0_SEL_TEMP_MONITOR;
  31
  32                 writel(val, pvtmon + PVTMON_CONTROL0);
  33         }
  34
  35         val = readl(pvtmon + PVTMON_STATUS);
  36         *temp = slope * val + offset;
  37
  38         return 0;
  39 }
  40
  41 static const struct thermal_zone_device_ops ns_thermal_ops = {
  42         .get_temp = ns_thermal_get_temp,
  43 };
  44
  45 static int ns_thermal_probe(struct platform_device *pdev)
  46 {
  47         struct device *dev = &pdev->dev;
  48         struct thermal_zone_device *tz;
  49         void __iomem *pvtmon;
  50
  51         pvtmon = of_iomap(dev_of_node(dev), 0);
  52         if (WARN_ON(!pvtmon))
  53                 return -ENOENT;
  54
  55         tz = devm_thermal_of_zone_register(dev, 0,
  56                                            pvtmon,
  57                                            &ns_thermal_ops);
  58         if (IS_ERR(tz)) {
  59                 iounmap(pvtmon);
  60                 return PTR_ERR(tz);
  61         }
  62
  63         platform_set_drvdata(pdev, pvtmon);
  64
  65         return 0;
  66 }
  67
  68 static void ns_thermal_remove(struct platform_device *pdev)
  69 {
  70         void __iomem *pvtmon = platform_get_drvdata(pdev);
  71
  72         iounmap(pvtmon);
  73 }
  74
  75 static const struct of_device_id ns_thermal_of_match[] = {
  76         { .compatible = "brcm,ns-thermal", },
  77         {},
  78 };
  79 MODULE_DEVICE_TABLE(of, ns_thermal_of_match);
  80
  81 static struct platform_driver ns_thermal_driver = {
  82         .probe          = ns_thermal_probe,
  83         .remove_new     = ns_thermal_remove,
  84         .driver = {
  85                 .name = "ns-thermal",
  86                 .of_match_table = ns_thermal_of_match,
  87         },
  88 };
  89 module_platform_driver(ns_thermal_driver);
  90
  91 MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>");
  92 MODULE_DESCRIPTION("Northstar thermal driver");
  93 MODULE_LICENSE("GPL v2");