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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 | // SPDX-License-Identifier: GPL-2.0-only /* * Kirkwood thermal sensor driver * * Copyright (C) 2012 Nobuhiro Iwamatsu <iwamatsu@nigauri.org> */ #include <linux/device.h> #include <linux/err.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/of.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/thermal.h> #define KIRKWOOD_THERMAL_VALID_OFFSET 9 #define KIRKWOOD_THERMAL_VALID_MASK 0x1 #define KIRKWOOD_THERMAL_TEMP_OFFSET 10 #define KIRKWOOD_THERMAL_TEMP_MASK 0x1FF /* Kirkwood Thermal Sensor Dev Structure */ struct kirkwood_thermal_priv { void __iomem *sensor; }; static int kirkwood_get_temp(struct thermal_zone_device *thermal, int *temp) { unsigned long reg; struct kirkwood_thermal_priv *priv = thermal_zone_device_priv(thermal); reg = readl_relaxed(priv->sensor); /* Valid check */ if (!((reg >> KIRKWOOD_THERMAL_VALID_OFFSET) & KIRKWOOD_THERMAL_VALID_MASK)) return -EIO; /* * Calculate temperature. According to Marvell internal * documentation the formula for this is: * Celsius = (322-reg)/1.3625 */ reg = (reg >> KIRKWOOD_THERMAL_TEMP_OFFSET) & KIRKWOOD_THERMAL_TEMP_MASK; *temp = ((3220000000UL - (10000000UL * reg)) / 13625); return 0; } static struct thermal_zone_device_ops ops = { .get_temp = kirkwood_get_temp, }; static const struct of_device_id kirkwood_thermal_id_table[] = { { .compatible = "marvell,kirkwood-thermal" }, {} }; static int kirkwood_thermal_probe(struct platform_device *pdev) { struct thermal_zone_device *thermal = NULL; struct kirkwood_thermal_priv *priv; int ret; priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->sensor = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); if (IS_ERR(priv->sensor)) return PTR_ERR(priv->sensor); thermal = thermal_zone_device_register("kirkwood_thermal", 0, 0, priv, &ops, NULL, 0, 0); if (IS_ERR(thermal)) { dev_err(&pdev->dev, "Failed to register thermal zone device\n"); return PTR_ERR(thermal); } ret = thermal_zone_device_enable(thermal); if (ret) { thermal_zone_device_unregister(thermal); dev_err(&pdev->dev, "Failed to enable thermal zone device\n"); return ret; } platform_set_drvdata(pdev, thermal); return 0; } static int kirkwood_thermal_exit(struct platform_device *pdev) { struct thermal_zone_device *kirkwood_thermal = platform_get_drvdata(pdev); thermal_zone_device_unregister(kirkwood_thermal); return 0; } MODULE_DEVICE_TABLE(of, kirkwood_thermal_id_table); static struct platform_driver kirkwood_thermal_driver = { .probe = kirkwood_thermal_probe, .remove = kirkwood_thermal_exit, .driver = { .name = "kirkwood_thermal", .of_match_table = kirkwood_thermal_id_table, }, }; module_platform_driver(kirkwood_thermal_driver); MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu@nigauri.org>"); MODULE_DESCRIPTION("kirkwood thermal driver"); MODULE_LICENSE("GPL"); |