121 lines
2.9 KiB
C
121 lines
2.9 KiB
C
// 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->devdata;
|
|
|
|
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;
|
|
struct resource *res;
|
|
int ret;
|
|
|
|
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
|
|
if (!priv)
|
|
return -ENOMEM;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
priv->sensor = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(priv->sensor))
|
|
return PTR_ERR(priv->sensor);
|
|
|
|
thermal = thermal_tripless_zone_device_register("kirkwood_thermal",
|
|
priv, &ops, NULL);
|
|
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");
|