linux/drivers/thermal/broadcom/ns-thermal.c
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   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
  17struct ns_thermal {
  18        struct thermal_zone_device *tz;
  19        void __iomem *pvtmon;
  20};
  21
  22static 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
  46static const struct thermal_zone_of_device_ops ns_thermal_ops = {
  47        .get_temp = ns_thermal_get_temp,
  48};
  49
  50static 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
  76static 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
  85static const struct of_device_id ns_thermal_of_match[] = {
  86        { .compatible = "brcm,ns-thermal", },
  87        {},
  88};
  89MODULE_DEVICE_TABLE(of, ns_thermal_of_match);
  90
  91static 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};
  99module_platform_driver(ns_thermal_driver);
 100
 101MODULE_AUTHOR("Rafał Miłecki <rafal@milecki.pl>");
 102MODULE_DESCRIPTION("Northstar thermal driver");
 103MODULE_LICENSE("GPL v2");
 104