Commit 0670b9ad authored by Armin Wolf's avatar Armin Wolf Committed by Rafael J. Wysocki
Browse files

ACPI: fan: Add basic notification support 



The ACPI specification states that the platform firmware can notify
the ACPI fan device that the fan speed has changed an that the _FST
control method should be reevaluated. Add support for this mechanism
to prepare for future changes.

Signed-off-by: default avatarArmin Wolf <W_Armin@gmx.de>
Link: https://patch.msgid.link/20251024183824.5656-2-W_Armin@gmx.de


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 2e00f7a4

drivers/acpi/fan_core.c

+50 −0
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ 


#include "fan.h"



#define ACPI_FAN_NOTIFY_STATE_CHANGED	0x80



static const struct acpi_device_id fan_device_ids[] = {

	ACPI_FAN_DEVICE_IDS,

	{"", 0},
@@ -308,6 +310,50 @@ static int acpi_fan_get_fps(struct acpi_device *device) 
	return status;

}



static void acpi_fan_notify_handler(acpi_handle handle, u32 event, void *context)

{

	struct device *dev = context;

	struct acpi_fan_fst fst;

	int ret;



	switch (event) {

	case ACPI_FAN_NOTIFY_STATE_CHANGED:

		/*

		 * The ACPI specification says that we must evaluate _FST when we

		 * receive an ACPI event indicating that the fan state has changed.

		 */

		ret = acpi_fan_get_fst(handle, &fst);

		if (ret < 0)

			dev_err(dev, "Error retrieving current fan status: %d\n", ret);



		acpi_bus_generate_netlink_event("fan", dev_name(dev), event, 0);

		break;

	default:

		dev_dbg(dev, "Unsupported ACPI notification 0x%x\n", event);

		break;

	}

}



static void acpi_fan_notify_remove(void *data)

{

	struct acpi_fan *fan = data;



	acpi_remove_notify_handler(fan->handle, ACPI_DEVICE_NOTIFY, acpi_fan_notify_handler);

}



static int devm_acpi_fan_notify_init(struct device *dev)

{

	struct acpi_fan *fan = dev_get_drvdata(dev);

	acpi_status status;



	status = acpi_install_notify_handler(fan->handle, ACPI_DEVICE_NOTIFY,

					     acpi_fan_notify_handler, dev);

	if (ACPI_FAILURE(status))

		return -EIO;



	return devm_add_action_or_reset(dev, acpi_fan_notify_remove, fan);

}



static int acpi_fan_probe(struct platform_device *pdev)

{

	int result = 0;
@@ -351,6 +397,10 @@ static int acpi_fan_probe(struct platform_device *pdev) 
		if (result)

			return result;



		result = devm_acpi_fan_notify_init(&pdev->dev);

		if (result)

			return result;



		result = acpi_fan_create_attributes(device);

		if (result)

			return result;