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// SPDX-License-Identifier: GPL-2.0+
/*
* Broadcom AVS RO thermal sensor driver
*
* based on brcmstb_thermal
*
* Copyright (C) 2020 Stefan Wahren
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/thermal.h>
#include "../thermal_hwmon.h"
#define AVS_RO_TEMP_STATUS 0x200
#define AVS_RO_TEMP_STATUS_VALID_MSK (BIT(16) | BIT(10))
#define AVS_RO_TEMP_STATUS_DATA_MSK GENMASK(9, 0)
struct bcm2711_thermal_priv {
struct regmap *regmap;
struct thermal_zone_device *thermal;
};
static int bcm2711_get_temp(struct thermal_zone_device *tz, int *temp)
{
struct bcm2711_thermal_priv *priv = thermal_zone_device_priv(tz);
int slope = thermal_zone_get_slope(tz);
int offset = thermal_zone_get_offset(tz);
u32 val;
int ret;
ret = regmap_read(priv->regmap, AVS_RO_TEMP_STATUS, &val);
if (ret)
return ret;
if (!(val & AVS_RO_TEMP_STATUS_VALID_MSK))
return -EIO;
val &= AVS_RO_TEMP_STATUS_DATA_MSK;
/* Convert a HW code to a temperature reading (millidegree celsius) */
*temp = slope * val + offset;
return 0;
}
static const struct thermal_zone_device_ops bcm2711_thermal_of_ops = {
.get_temp = bcm2711_get_temp,
};
static const struct of_device_id bcm2711_thermal_id_table[] = {
{ .compatible = "brcm,bcm2711-thermal" },
{},
};
MODULE_DEVICE_TABLE(of, bcm2711_thermal_id_table);
static int bcm2711_thermal_probe(struct platform_device *pdev)
{
struct thermal_zone_device *thermal;
struct bcm2711_thermal_priv *priv;
struct device *dev = &pdev->dev;
struct device_node *parent;
struct regmap *regmap;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
/* get regmap from syscon node */
parent = of_get_parent(dev->of_node); /* parent should be syscon node */
regmap = syscon_node_to_regmap(parent);
of_node_put(parent);
if (IS_ERR(regmap)) {
ret = PTR_ERR(regmap);
dev_err(dev, "failed to get regmap: %d\n", ret);
return ret;
}
priv->regmap = regmap;
thermal = devm_thermal_of_zone_register(dev, 0, priv,
&bcm2711_thermal_of_ops);
if (IS_ERR(thermal)) {
ret = PTR_ERR(thermal);
dev_err(dev, "could not register sensor: %d\n", ret);
return ret;
}
priv->thermal = thermal;
return thermal_add_hwmon_sysfs(thermal);
}
static struct platform_driver bcm2711_thermal_driver = {
.probe = bcm2711_thermal_probe,
.driver = {
.name = "bcm2711_thermal",
.of_match_table = bcm2711_thermal_id_table,
},
};
module_platform_driver(bcm2711_thermal_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Stefan Wahren");
MODULE_DESCRIPTION("Broadcom AVS RO thermal sensor driver");
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