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1// SPDX-License-Identifier: GPL-2.0+2/*3 * Broadcom AVS RO thermal sensor driver4 *5 * based on brcmstb_thermal6 *7 * Copyright (C) 2020 Stefan Wahren8 */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/of.h>19#include <linux/platform_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 0x20026#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(struct thermal_zone_device *tz, int *temp)35{36 struct bcm2711_thermal_priv *priv = thermal_zone_device_priv(tz);37 int slope = thermal_zone_get_slope(tz);38 int offset = thermal_zone_get_offset(tz);39 u32 val;40 int ret;41 42 ret = regmap_read(priv->regmap, AVS_RO_TEMP_STATUS, &val);43 if (ret)44 return ret;45 46 if (!(val & AVS_RO_TEMP_STATUS_VALID_MSK))47 return -EIO;48 49 val &= AVS_RO_TEMP_STATUS_DATA_MSK;50 51 /* Convert a HW code to a temperature reading (millidegree celsius) */52 *temp = slope * val + offset;53 54 return 0;55}56 57static const struct thermal_zone_device_ops bcm2711_thermal_of_ops = {58 .get_temp = bcm2711_get_temp,59};60 61static const struct of_device_id bcm2711_thermal_id_table[] = {62 { .compatible = "brcm,bcm2711-thermal" },63 {},64};65MODULE_DEVICE_TABLE(of, bcm2711_thermal_id_table);66 67static int bcm2711_thermal_probe(struct platform_device *pdev)68{69 struct thermal_zone_device *thermal;70 struct bcm2711_thermal_priv *priv;71 struct device *dev = &pdev->dev;72 struct device_node *parent;73 struct regmap *regmap;74 int ret;75 76 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);77 if (!priv)78 return -ENOMEM;79 80 /* get regmap from syscon node */81 parent = of_get_parent(dev->of_node); /* parent should be syscon node */82 regmap = syscon_node_to_regmap(parent);83 of_node_put(parent);84 if (IS_ERR(regmap)) {85 ret = PTR_ERR(regmap);86 dev_err(dev, "failed to get regmap: %d\n", ret);87 return ret;88 }89 priv->regmap = regmap;90 91 thermal = devm_thermal_of_zone_register(dev, 0, priv,92 &bcm2711_thermal_of_ops);93 if (IS_ERR(thermal)) {94 ret = PTR_ERR(thermal);95 dev_err(dev, "could not register sensor: %d\n", ret);96 return ret;97 }98 99 priv->thermal = thermal;100 101 return thermal_add_hwmon_sysfs(thermal);102}103 104static struct platform_driver bcm2711_thermal_driver = {105 .probe = bcm2711_thermal_probe,106 .driver = {107 .name = "bcm2711_thermal",108 .of_match_table = bcm2711_thermal_id_table,109 },110};111module_platform_driver(bcm2711_thermal_driver);112 113MODULE_LICENSE("GPL");114MODULE_AUTHOR("Stefan Wahren");115MODULE_DESCRIPTION("Broadcom AVS RO thermal sensor driver");116