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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Kirkwood thermal sensor driver4 *5 * Copyright (C) 2012 Nobuhiro Iwamatsu <iwamatsu@nigauri.org>6 */7#include <linux/device.h>8#include <linux/err.h>9#include <linux/io.h>10#include <linux/kernel.h>11#include <linux/of.h>12#include <linux/module.h>13#include <linux/platform_device.h>14#include <linux/thermal.h>15 16#define KIRKWOOD_THERMAL_VALID_OFFSET 917#define KIRKWOOD_THERMAL_VALID_MASK 0x118#define KIRKWOOD_THERMAL_TEMP_OFFSET 1019#define KIRKWOOD_THERMAL_TEMP_MASK 0x1FF20 21/* Kirkwood Thermal Sensor Dev Structure */22struct kirkwood_thermal_priv {23 void __iomem *sensor;24};25 26static int kirkwood_get_temp(struct thermal_zone_device *thermal,27 int *temp)28{29 unsigned long reg;30 struct kirkwood_thermal_priv *priv = thermal_zone_device_priv(thermal);31 32 reg = readl_relaxed(priv->sensor);33 34 /* Valid check */35 if (!((reg >> KIRKWOOD_THERMAL_VALID_OFFSET) &36 KIRKWOOD_THERMAL_VALID_MASK))37 return -EIO;38 39 /*40 * Calculate temperature. According to Marvell internal41 * documentation the formula for this is:42 * Celsius = (322-reg)/1.362543 */44 reg = (reg >> KIRKWOOD_THERMAL_TEMP_OFFSET) &45 KIRKWOOD_THERMAL_TEMP_MASK;46 *temp = ((3220000000UL - (10000000UL * reg)) / 13625);47 48 return 0;49}50 51static struct thermal_zone_device_ops ops = {52 .get_temp = kirkwood_get_temp,53};54 55static const struct of_device_id kirkwood_thermal_id_table[] = {56 { .compatible = "marvell,kirkwood-thermal" },57 {}58};59 60static int kirkwood_thermal_probe(struct platform_device *pdev)61{62 struct thermal_zone_device *thermal = NULL;63 struct kirkwood_thermal_priv *priv;64 int ret;65 66 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);67 if (!priv)68 return -ENOMEM;69 70 priv->sensor = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);71 if (IS_ERR(priv->sensor))72 return PTR_ERR(priv->sensor);73 74 thermal = thermal_tripless_zone_device_register("kirkwood_thermal",75 priv, &ops, NULL);76 if (IS_ERR(thermal)) {77 dev_err(&pdev->dev,78 "Failed to register thermal zone device\n");79 return PTR_ERR(thermal);80 }81 ret = thermal_zone_device_enable(thermal);82 if (ret) {83 thermal_zone_device_unregister(thermal);84 dev_err(&pdev->dev, "Failed to enable thermal zone device\n");85 return ret;86 }87 88 platform_set_drvdata(pdev, thermal);89 90 return 0;91}92 93static void kirkwood_thermal_exit(struct platform_device *pdev)94{95 struct thermal_zone_device *kirkwood_thermal =96 platform_get_drvdata(pdev);97 98 thermal_zone_device_unregister(kirkwood_thermal);99}100 101MODULE_DEVICE_TABLE(of, kirkwood_thermal_id_table);102 103static struct platform_driver kirkwood_thermal_driver = {104 .probe = kirkwood_thermal_probe,105 .remove_new = kirkwood_thermal_exit,106 .driver = {107 .name = "kirkwood_thermal",108 .of_match_table = kirkwood_thermal_id_table,109 },110};111 112module_platform_driver(kirkwood_thermal_driver);113 114MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu@nigauri.org>");115MODULE_DESCRIPTION("kirkwood thermal driver");116MODULE_LICENSE("GPL");117