diff options
Diffstat (limited to 'drivers/hwmon/surface_fan.c')
-rw-r--r-- | drivers/hwmon/surface_fan.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/drivers/hwmon/surface_fan.c b/drivers/hwmon/surface_fan.c new file mode 100644 index 0000000000..de3c5a2409 --- /dev/null +++ b/drivers/hwmon/surface_fan.c @@ -0,0 +1,91 @@ +// 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"); |