drivers/thermal/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 struct ns_thermal {
  18         struct thermal_zone_device *tz;
  19         void __iomem *pvtmon;
  20 };
  21
  22 static int ns_thermal_get_temp(void *data, int *temp)
  23 {
  24         struct ns_thermal *ns_thermal = data;
  25         int offset = thermal_zone_get_offset(ns_thermal->tz);
  26         int slope = thermal_zone_get_slope(ns_thermal->tz);
  27         u32 val;
  28
  29         val = readl(ns_thermal->pvtmon + PVTMON_CONTROL0);
  30         if ((val & PVTMON_CONTROL0_SEL_MASK) != PVTMON_CONTROL0_SEL_TEMP_MONITOR) {
  31                 /* Clear current mode selection */
  32                 val &= ~PVTMON_CONTROL0_SEL_MASK;
  33
  34                 /* Set temp monitor mode (it's the default actually) */
  35                 val |= PVTMON_CONTROL0_SEL_TEMP_MONITOR;
  36
  37                 writel(val, ns_thermal->pvtmon + PVTMON_CONTROL0);
  38         }
  39
  40         val = readl(ns_thermal->pvtmon + PVTMON_STATUS);
  41         *temp = slope * val + offset;
  42
  43         return 0;
  44 }
  45
  46 static const struct thermal_zone_of_device_ops ns_thermal_ops = {
  47         .get_temp = ns_thermal_get_temp,
  48 };
  49
  50 static int ns_thermal_probe(struct platform_device *pdev)
  51 {
  52         struct device *dev = &pdev->dev;
  53         struct ns_thermal *ns_thermal;
  54
  55         ns_thermal = devm_kzalloc(dev, sizeof(*ns_thermal), GFP_KERNEL);
  56         if (!ns_thermal)
  57                 return -ENOMEM;
  58
  59         ns_thermal->pvtmon = of_iomap(dev_of_node(dev), 0);
  60         if (WARN_ON(!ns_thermal->pvtmon))
  61                 return -ENOENT;
  62
  63         ns_thermal->tz = devm_thermal_zone_of_sensor_register(dev, 0,
  64                                                               ns_thermal,
  65                                                               &ns_thermal_ops);
  66         if (IS_ERR(ns_thermal->tz)) {
  67                 iounmap(ns_thermal->pvtmon);
  68                 return PTR_ERR(ns_thermal->tz);
  69         }
  70
  71         platform_set_drvdata(pdev, ns_thermal);
  72
  73         return 0;
  74 }
  75
  76 static int ns_thermal_remove(struct platform_device *pdev)
  77 {
  78         struct ns_thermal *ns_thermal = platform_get_drvdata(pdev);
  79
  80         iounmap(ns_thermal->pvtmon);
  81
  82         return 0;
  83 }
  84
  85 static const struct of_device_id ns_thermal_of_match[] = {
  86         { .compatible = "brcm,ns-thermal", },
  87         {},
  88 };
  89 MODULE_DEVICE_TABLE(of, ns_thermal_of_match);
  90
  91 static struct platform_driver ns_thermal_driver = {
  92         .probe          = ns_thermal_probe,
  93         .remove         = ns_thermal_remove,
  94         .driver = {
  95                 .name = "ns-thermal",
  96                 .of_match_table = ns_thermal_of_match,
  97         },
  98 };
  99 module_platform_driver(ns_thermal_driver);
 100
 101 MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>");
 102 MODULE_DESCRIPTION("Northstar thermal driver");
 103 MODULE_LICENSE("GPL v2");