linux/drivers/hwmon/surface_fan.c

92 lines
2.1 KiB
C
Raw Permalink Normal View History

// SPDX-License-Identifier: GPL-2.0+
/*
* Surface Fan driver for Surface System Aggregator Module. It provides access
* to the fan's rpm through the hwmon system.
*
* Copyright (C) 2023 Ivor Wanders <ivor@iwanders.net>
*/
#include <linux/hwmon.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/surface_aggregator/device.h>
#include <linux/types.h>
// SSAM
SSAM_DEFINE_SYNC_REQUEST_CL_R(__ssam_fan_rpm_get, __le16, {
.target_category = SSAM_SSH_TC_FAN,
.command_id = 0x01,
});
// hwmon
static umode_t surface_fan_hwmon_is_visible(const void *drvdata,
enum hwmon_sensor_types type, u32 attr,
int channel)
{
return 0444;
}
static int surface_fan_hwmon_read(struct device *dev,
enum hwmon_sensor_types type, u32 attr,
int channel, long *val)
{
struct ssam_device *sdev = dev_get_drvdata(dev);
int ret;
__le16 value;
ret = __ssam_fan_rpm_get(sdev, &value);
if (ret)
return ret;
*val = le16_to_cpu(value);
return 0;
}
static const struct hwmon_channel_info *const surface_fan_info[] = {
HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
NULL
};
static const struct hwmon_ops surface_fan_hwmon_ops = {
.is_visible = surface_fan_hwmon_is_visible,
.read = surface_fan_hwmon_read,
};
static const struct hwmon_chip_info surface_fan_chip_info = {
.ops = &surface_fan_hwmon_ops,
.info = surface_fan_info,
};
static int surface_fan_probe(struct ssam_device *sdev)
{
struct device *hdev;
hdev = devm_hwmon_device_register_with_info(&sdev->dev,
"surface_fan", sdev,
&surface_fan_chip_info,
NULL);
return PTR_ERR_OR_ZERO(hdev);
}
static const struct ssam_device_id ssam_fan_match[] = {
{ SSAM_SDEV(FAN, SAM, 0x01, 0x01) },
{},
};
MODULE_DEVICE_TABLE(ssam, ssam_fan_match);
static struct ssam_device_driver surface_fan = {
.probe = surface_fan_probe,
.match_table = ssam_fan_match,
.driver = {
.name = "surface_fan",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
};
module_ssam_device_driver(surface_fan);
MODULE_AUTHOR("Ivor Wanders <ivor@iwanders.net>");
MODULE_DESCRIPTION("Fan Driver for Surface System Aggregator Module");
MODULE_LICENSE("GPL");