106e0121e2
The thermal sensor on BCM2711 is capable of negative temperatures, so don't
clamp the measurements at zero. Since this was the only use for variable t,
drop it.
This change based on a patch by Dom Cobley, who also tested the fix.
Fixes: 59b781352d ("thermal: Add BCM2711 thermal driver")
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220412195423.104511-1-stefan.wahren@i2se.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
117 lines
2.8 KiB
C
117 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Broadcom AVS RO thermal sensor driver
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*
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* based on brcmstb_thermal
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*
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* Copyright (C) 2020 Stefan Wahren
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*/
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#include <linux/bitops.h>
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#include <linux/clk.h>
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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/mfd/syscon.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/of_device.h>
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#include <linux/regmap.h>
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#include <linux/thermal.h>
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#include "../thermal_hwmon.h"
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#define AVS_RO_TEMP_STATUS 0x200
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#define AVS_RO_TEMP_STATUS_VALID_MSK (BIT(16) | BIT(10))
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#define AVS_RO_TEMP_STATUS_DATA_MSK GENMASK(9, 0)
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struct bcm2711_thermal_priv {
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struct regmap *regmap;
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struct thermal_zone_device *thermal;
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};
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static int bcm2711_get_temp(void *data, int *temp)
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{
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struct bcm2711_thermal_priv *priv = data;
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int slope = thermal_zone_get_slope(priv->thermal);
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int offset = thermal_zone_get_offset(priv->thermal);
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u32 val;
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int ret;
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ret = regmap_read(priv->regmap, AVS_RO_TEMP_STATUS, &val);
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if (ret)
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return ret;
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if (!(val & AVS_RO_TEMP_STATUS_VALID_MSK))
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return -EIO;
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val &= AVS_RO_TEMP_STATUS_DATA_MSK;
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/* Convert a HW code to a temperature reading (millidegree celsius) */
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*temp = slope * val + offset;
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return 0;
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}
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static const struct thermal_zone_of_device_ops bcm2711_thermal_of_ops = {
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.get_temp = bcm2711_get_temp,
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};
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static const struct of_device_id bcm2711_thermal_id_table[] = {
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{ .compatible = "brcm,bcm2711-thermal" },
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{},
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};
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MODULE_DEVICE_TABLE(of, bcm2711_thermal_id_table);
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static int bcm2711_thermal_probe(struct platform_device *pdev)
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{
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struct thermal_zone_device *thermal;
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struct bcm2711_thermal_priv *priv;
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struct device *dev = &pdev->dev;
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struct device_node *parent;
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struct regmap *regmap;
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int ret;
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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/* get regmap from syscon node */
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parent = of_get_parent(dev->of_node); /* parent should be syscon node */
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regmap = syscon_node_to_regmap(parent);
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of_node_put(parent);
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if (IS_ERR(regmap)) {
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ret = PTR_ERR(regmap);
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dev_err(dev, "failed to get regmap: %d\n", ret);
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return ret;
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}
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priv->regmap = regmap;
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thermal = devm_thermal_zone_of_sensor_register(dev, 0, priv,
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&bcm2711_thermal_of_ops);
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if (IS_ERR(thermal)) {
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ret = PTR_ERR(thermal);
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dev_err(dev, "could not register sensor: %d\n", ret);
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return ret;
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}
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priv->thermal = thermal;
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thermal->tzp->no_hwmon = false;
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return thermal_add_hwmon_sysfs(thermal);
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}
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static struct platform_driver bcm2711_thermal_driver = {
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.probe = bcm2711_thermal_probe,
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.driver = {
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.name = "bcm2711_thermal",
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.of_match_table = bcm2711_thermal_id_table,
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},
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};
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module_platform_driver(bcm2711_thermal_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Stefan Wahren");
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MODULE_DESCRIPTION("Broadcom AVS RO thermal sensor driver");
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