LXR linux/drivers/thermal/broadcom/ns-thermal.c

   1/*
   2 * Copyright (C) 2017 Rafał Miłecki <rafal@milecki.pl>
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation.
   7 */
   8
   9#include <linux/module.h>
  10#include <linux/of_address.h>
  11#include <linux/platform_device.h>
  12#include <linux/thermal.h>
  13
  14#define PVTMON_CONTROL0                                 0x00
  15#define PVTMON_CONTROL0_SEL_MASK                        0x0000000e
  16#define PVTMON_CONTROL0_SEL_TEMP_MONITOR                0x00000000
  17#define PVTMON_CONTROL0_SEL_TEST_MODE                   0x0000000e
  18#define PVTMON_STATUS                                   0x08
  19
  20struct ns_thermal {
  21        struct thermal_zone_device *tz;
  22        void __iomem *pvtmon;
  23};
  24
  25static int ns_thermal_get_temp(void *data, int *temp)
  26{
  27        struct ns_thermal *ns_thermal = data;
  28        int offset = thermal_zone_get_offset(ns_thermal->tz);
  29        int slope = thermal_zone_get_slope(ns_thermal->tz);
  30        u32 val;
  31
  32        val = readl(ns_thermal->pvtmon + PVTMON_CONTROL0);
  33        if ((val & PVTMON_CONTROL0_SEL_MASK) != PVTMON_CONTROL0_SEL_TEMP_MONITOR) {
  34                /* Clear current mode selection */
  35                val &= ~PVTMON_CONTROL0_SEL_MASK;
  36
  37                /* Set temp monitor mode (it's the default actually) */
  38                val |= PVTMON_CONTROL0_SEL_TEMP_MONITOR;
  39
  40                writel(val, ns_thermal->pvtmon + PVTMON_CONTROL0);
  41        }
  42
  43        val = readl(ns_thermal->pvtmon + PVTMON_STATUS);
  44        *temp = slope * val + offset;
  45
  46        return 0;
  47}
  48
  49static const struct thermal_zone_of_device_ops ns_thermal_ops = {
  50        .get_temp = ns_thermal_get_temp,
  51};
  52
  53static int ns_thermal_probe(struct platform_device *pdev)
  54{
  55        struct device *dev = &pdev->dev;
  56        struct ns_thermal *ns_thermal;
  57
  58        ns_thermal = devm_kzalloc(dev, sizeof(*ns_thermal), GFP_KERNEL);
  59        if (!ns_thermal)
  60                return -ENOMEM;
  61
  62        ns_thermal->pvtmon = of_iomap(dev_of_node(dev), 0);
  63        if (WARN_ON(!ns_thermal->pvtmon))
  64                return -ENOENT;
  65
  66        ns_thermal->tz = devm_thermal_zone_of_sensor_register(dev, 0,
  67                                                              ns_thermal,
  68                                                              &ns_thermal_ops);
  69        if (IS_ERR(ns_thermal->tz)) {
  70                iounmap(ns_thermal->pvtmon);
  71                return PTR_ERR(ns_thermal->tz);
  72        }
  73
  74        platform_set_drvdata(pdev, ns_thermal);
  75
  76        return 0;
  77}
  78
  79static int ns_thermal_remove(struct platform_device *pdev)
  80{
  81        struct ns_thermal *ns_thermal = platform_get_drvdata(pdev);
  82
  83        iounmap(ns_thermal->pvtmon);
  84
  85        return 0;
  86}
  87
  88static const struct of_device_id ns_thermal_of_match[] = {
  89        { .compatible = "brcm,ns-thermal", },
  90        {},
  91};
  92MODULE_DEVICE_TABLE(of, ns_thermal_of_match);
  93
  94static struct platform_driver ns_thermal_driver = {
  95        .probe          = ns_thermal_probe,
  96        .remove         = ns_thermal_remove,
  97        .driver = {
  98                .name = "ns-thermal",
  99                .of_match_table = ns_thermal_of_match,
 100        },
 101};
 102module_platform_driver(ns_thermal_driver);
 103
 104MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>");
 105MODULE_DESCRIPTION("Northstar thermal driver");
 106MODULE_LICENSE("GPL v2");
 107