LXR linux/drivers/thermal/broadcom/bcm2711

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Broadcom AVS RO thermal sensor driver
   4 *
   5 * based on brcmstb_thermal
   6 *
   7 * Copyright (C) 2020 Stefan Wahren
   8 */
   9
  10#include <linux/bitops.h>
  11#include <linux/clk.h>
  12#include <linux/device.h>
  13#include <linux/err.h>
  14#include <linux/io.h>
  15#include <linux/kernel.h>
  16#include <linux/mfd/syscon.h>
  17#include <linux/module.h>
  18#include <linux/platform_device.h>
  19#include <linux/of_device.h>
  20#include <linux/regmap.h>
  21#include <linux/thermal.h>
  22
  23#include "../thermal_hwmon.h"
  24
  25#define AVS_RO_TEMP_STATUS              0x200
  26#define AVS_RO_TEMP_STATUS_VALID_MSK    (BIT(16) | BIT(10))
  27#define AVS_RO_TEMP_STATUS_DATA_MSK     GENMASK(9, 0)
  28
  29struct bcm2711_thermal_priv {
  30        struct regmap *regmap;
  31        struct thermal_zone_device *thermal;
  32};
  33
  34static int bcm2711_get_temp(void *data, int *temp)
  35{
  36        struct bcm2711_thermal_priv *priv = data;
  37        int slope = thermal_zone_get_slope(priv->thermal);
  38        int offset = thermal_zone_get_offset(priv->thermal);
  39        u32 val;
  40        int ret;
  41        long t;
  42
  43        ret = regmap_read(priv->regmap, AVS_RO_TEMP_STATUS, &val);
  44        if (ret)
  45                return ret;
  46
  47        if (!(val & AVS_RO_TEMP_STATUS_VALID_MSK))
  48                return -EIO;
  49
  50        val &= AVS_RO_TEMP_STATUS_DATA_MSK;
  51
  52        /* Convert a HW code to a temperature reading (millidegree celsius) */
  53        t = slope * val + offset;
  54
  55        *temp = t < 0 ? 0 : t;
  56
  57        return 0;
  58}
  59
  60static const struct thermal_zone_of_device_ops bcm2711_thermal_of_ops = {
  61        .get_temp       = bcm2711_get_temp,
  62};
  63
  64static const struct of_device_id bcm2711_thermal_id_table[] = {
  65        { .compatible = "brcm,bcm2711-thermal" },
  66        {},
  67};
  68MODULE_DEVICE_TABLE(of, bcm2711_thermal_id_table);
  69
  70static int bcm2711_thermal_probe(struct platform_device *pdev)
  71{
  72        struct thermal_zone_device *thermal;
  73        struct bcm2711_thermal_priv *priv;
  74        struct device *dev = &pdev->dev;
  75        struct device_node *parent;
  76        struct regmap *regmap;
  77        int ret;
  78
  79        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  80        if (!priv)
  81                return -ENOMEM;
  82
  83        /* get regmap from syscon node */
  84        parent = of_get_parent(dev->of_node); /* parent should be syscon node */
  85        regmap = syscon_node_to_regmap(parent);
  86        of_node_put(parent);
  87        if (IS_ERR(regmap)) {
  88                ret = PTR_ERR(regmap);
  89                dev_err(dev, "failed to get regmap: %d\n", ret);
  90                return ret;
  91        }
  92        priv->regmap = regmap;
  93
  94        thermal = devm_thermal_zone_of_sensor_register(dev, 0, priv,
  95                                                       &bcm2711_thermal_of_ops);
  96        if (IS_ERR(thermal)) {
  97                ret = PTR_ERR(thermal);
  98                dev_err(dev, "could not register sensor: %d\n", ret);
  99                return ret;
 100        }
 101
 102        priv->thermal = thermal;
 103
 104        thermal->tzp->no_hwmon = false;
 105        return thermal_add_hwmon_sysfs(thermal);
 106}
 107
 108static struct platform_driver bcm2711_thermal_driver = {
 109        .probe = bcm2711_thermal_probe,
 110        .driver = {
 111                .name = "bcm2711_thermal",
 112                .of_match_table = bcm2711_thermal_id_table,
 113        },
 114};
 115module_platform_driver(bcm2711_thermal_driver);
 116
 117MODULE_LICENSE("GPL");
 118MODULE_AUTHOR("Stefan Wahren");
 119MODULE_DESCRIPTION("Broadcom AVS RO thermal sensor driver");
 120