143 lines
3.2 KiB
C
143 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* sl28cpld hardware monitoring driver
|
|
*
|
|
* Copyright 2020 Kontron Europe GmbH
|
|
*/
|
|
|
|
#include <linux/bitfield.h>
|
|
#include <linux/hwmon.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mod_devicetable.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/property.h>
|
|
#include <linux/regmap.h>
|
|
|
|
#define FAN_INPUT 0x00
|
|
#define FAN_SCALE_X8 BIT(7)
|
|
#define FAN_VALUE_MASK GENMASK(6, 0)
|
|
|
|
struct sl28cpld_hwmon {
|
|
struct regmap *regmap;
|
|
u32 offset;
|
|
};
|
|
|
|
static umode_t sl28cpld_hwmon_is_visible(const void *data,
|
|
enum hwmon_sensor_types type,
|
|
u32 attr, int channel)
|
|
{
|
|
return 0444;
|
|
}
|
|
|
|
static int sl28cpld_hwmon_read(struct device *dev,
|
|
enum hwmon_sensor_types type, u32 attr,
|
|
int channel, long *input)
|
|
{
|
|
struct sl28cpld_hwmon *hwmon = dev_get_drvdata(dev);
|
|
unsigned int value;
|
|
int ret;
|
|
|
|
switch (attr) {
|
|
case hwmon_fan_input:
|
|
ret = regmap_read(hwmon->regmap, hwmon->offset + FAN_INPUT,
|
|
&value);
|
|
if (ret)
|
|
return ret;
|
|
/*
|
|
* The register has a 7 bit value and 1 bit which indicates the
|
|
* scale. If the MSB is set, then the lower 7 bit has to be
|
|
* multiplied by 8, to get the correct reading.
|
|
*/
|
|
if (value & FAN_SCALE_X8)
|
|
value = FIELD_GET(FAN_VALUE_MASK, value) << 3;
|
|
|
|
/*
|
|
* The counter period is 1000ms and the sysfs specification
|
|
* says we should asssume 2 pulses per revolution.
|
|
*/
|
|
value *= 60 / 2;
|
|
|
|
break;
|
|
default:
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
*input = value;
|
|
return 0;
|
|
}
|
|
|
|
static const u32 sl28cpld_hwmon_fan_config[] = {
|
|
HWMON_F_INPUT,
|
|
0
|
|
};
|
|
|
|
static const struct hwmon_channel_info sl28cpld_hwmon_fan = {
|
|
.type = hwmon_fan,
|
|
.config = sl28cpld_hwmon_fan_config,
|
|
};
|
|
|
|
static const struct hwmon_channel_info *sl28cpld_hwmon_info[] = {
|
|
&sl28cpld_hwmon_fan,
|
|
NULL
|
|
};
|
|
|
|
static const struct hwmon_ops sl28cpld_hwmon_ops = {
|
|
.is_visible = sl28cpld_hwmon_is_visible,
|
|
.read = sl28cpld_hwmon_read,
|
|
};
|
|
|
|
static const struct hwmon_chip_info sl28cpld_hwmon_chip_info = {
|
|
.ops = &sl28cpld_hwmon_ops,
|
|
.info = sl28cpld_hwmon_info,
|
|
};
|
|
|
|
static int sl28cpld_hwmon_probe(struct platform_device *pdev)
|
|
{
|
|
struct sl28cpld_hwmon *hwmon;
|
|
struct device *hwmon_dev;
|
|
int ret;
|
|
|
|
if (!pdev->dev.parent)
|
|
return -ENODEV;
|
|
|
|
hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
|
|
if (!hwmon)
|
|
return -ENOMEM;
|
|
|
|
hwmon->regmap = dev_get_regmap(pdev->dev.parent, NULL);
|
|
if (!hwmon->regmap)
|
|
return -ENODEV;
|
|
|
|
ret = device_property_read_u32(&pdev->dev, "reg", &hwmon->offset);
|
|
if (ret)
|
|
return -EINVAL;
|
|
|
|
hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
|
|
"sl28cpld_hwmon", hwmon,
|
|
&sl28cpld_hwmon_chip_info, NULL);
|
|
if (IS_ERR(hwmon_dev))
|
|
dev_err(&pdev->dev, "failed to register as hwmon device");
|
|
|
|
return PTR_ERR_OR_ZERO(hwmon_dev);
|
|
}
|
|
|
|
static const struct of_device_id sl28cpld_hwmon_of_match[] = {
|
|
{ .compatible = "kontron,sl28cpld-fan" },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(of, sl28cpld_hwmon_of_match);
|
|
|
|
static struct platform_driver sl28cpld_hwmon_driver = {
|
|
.probe = sl28cpld_hwmon_probe,
|
|
.driver = {
|
|
.name = "sl28cpld-fan",
|
|
.of_match_table = sl28cpld_hwmon_of_match,
|
|
},
|
|
};
|
|
module_platform_driver(sl28cpld_hwmon_driver);
|
|
|
|
MODULE_DESCRIPTION("sl28cpld Hardware Monitoring Driver");
|
|
MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
|
|
MODULE_LICENSE("GPL");
|