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123 lines
3.0 KiB
123 lines
3.0 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Kirkwood thermal sensor driver |
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* |
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* Copyright (C) 2012 Nobuhiro Iwamatsu <[email protected]> |
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*/ |
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/io.h> |
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#include <linux/kernel.h> |
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#include <linux/of.h> |
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#include <linux/module.h> |
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#include <linux/platform_device.h> |
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#include <linux/thermal.h> |
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#define KIRKWOOD_THERMAL_VALID_OFFSET 9 |
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#define KIRKWOOD_THERMAL_VALID_MASK 0x1 |
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#define KIRKWOOD_THERMAL_TEMP_OFFSET 10 |
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#define KIRKWOOD_THERMAL_TEMP_MASK 0x1FF |
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/* Kirkwood Thermal Sensor Dev Structure */ |
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struct kirkwood_thermal_priv { |
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void __iomem *sensor; |
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}; |
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static int kirkwood_get_temp(struct thermal_zone_device *thermal, |
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int *temp) |
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{ |
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unsigned long reg; |
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struct kirkwood_thermal_priv *priv = thermal->devdata; |
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reg = readl_relaxed(priv->sensor); |
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/* Valid check */ |
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if (!((reg >> KIRKWOOD_THERMAL_VALID_OFFSET) & |
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KIRKWOOD_THERMAL_VALID_MASK)) { |
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dev_err(&thermal->device, |
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"Temperature sensor reading not valid\n"); |
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return -EIO; |
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} |
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/* |
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* Calculate temperature. According to Marvell internal |
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* documentation the formula for this is: |
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* Celsius = (322-reg)/1.3625 |
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*/ |
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reg = (reg >> KIRKWOOD_THERMAL_TEMP_OFFSET) & |
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KIRKWOOD_THERMAL_TEMP_MASK; |
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*temp = ((3220000000UL - (10000000UL * reg)) / 13625); |
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return 0; |
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} |
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static struct thermal_zone_device_ops ops = { |
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.get_temp = kirkwood_get_temp, |
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}; |
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static const struct of_device_id kirkwood_thermal_id_table[] = { |
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{ .compatible = "marvell,kirkwood-thermal" }, |
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{} |
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}; |
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static int kirkwood_thermal_probe(struct platform_device *pdev) |
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{ |
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struct thermal_zone_device *thermal = NULL; |
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struct kirkwood_thermal_priv *priv; |
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struct resource *res; |
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int ret; |
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); |
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if (!priv) |
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return -ENOMEM; |
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
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priv->sensor = devm_ioremap_resource(&pdev->dev, res); |
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if (IS_ERR(priv->sensor)) |
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return PTR_ERR(priv->sensor); |
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thermal = thermal_zone_device_register("kirkwood_thermal", 0, 0, |
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priv, &ops, NULL, 0, 0); |
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if (IS_ERR(thermal)) { |
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dev_err(&pdev->dev, |
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"Failed to register thermal zone device\n"); |
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return PTR_ERR(thermal); |
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} |
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ret = thermal_zone_device_enable(thermal); |
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if (ret) { |
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thermal_zone_device_unregister(thermal); |
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dev_err(&pdev->dev, "Failed to enable thermal zone device\n"); |
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return ret; |
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} |
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platform_set_drvdata(pdev, thermal); |
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return 0; |
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} |
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static int kirkwood_thermal_exit(struct platform_device *pdev) |
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{ |
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struct thermal_zone_device *kirkwood_thermal = |
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platform_get_drvdata(pdev); |
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thermal_zone_device_unregister(kirkwood_thermal); |
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return 0; |
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} |
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MODULE_DEVICE_TABLE(of, kirkwood_thermal_id_table); |
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static struct platform_driver kirkwood_thermal_driver = { |
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.probe = kirkwood_thermal_probe, |
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.remove = kirkwood_thermal_exit, |
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.driver = { |
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.name = "kirkwood_thermal", |
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.of_match_table = kirkwood_thermal_id_table, |
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}, |
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}; |
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module_platform_driver(kirkwood_thermal_driver); |
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MODULE_AUTHOR("Nobuhiro Iwamatsu <[email protected]>"); |
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MODULE_DESCRIPTION("kirkwood thermal driver"); |
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MODULE_LICENSE("GPL");
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