Commit 7e12715e authored by Jesse Barnes's avatar Jesse Barnes Committed by Eric Anholt
Browse files

ACPI button: provide lid status functions 



Some drivers need to know when a lid event occurs and get the current
status.  This can be useful for when a platform firmware clobbers some
hardware state at lid time, and a driver needs to restore things when
the lid is opened again.

Acked-by: default avatarMatthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: default avatarEric Anholt <eric@anholt.net>
parent af729a26

drivers/acpi/button.c

+43 −2
Original line number Diff line number Diff line
@@ -113,6 +113,9 @@ static const struct file_operations acpi_button_state_fops = { 
	.release = single_release,

};



static BLOCKING_NOTIFIER_HEAD(acpi_lid_notifier);

static struct acpi_device *lid_device;



/* --------------------------------------------------------------------------

                              FS Interface (/proc)

   -------------------------------------------------------------------------- */
@@ -229,11 +232,38 @@ static int acpi_button_remove_fs(struct acpi_device *device) 
/* --------------------------------------------------------------------------

                                Driver Interface

   -------------------------------------------------------------------------- */

int acpi_lid_notifier_register(struct notifier_block *nb)

{

	return blocking_notifier_chain_register(&acpi_lid_notifier, nb);

}

EXPORT_SYMBOL(acpi_lid_notifier_register);



int acpi_lid_notifier_unregister(struct notifier_block *nb)

{

	return blocking_notifier_chain_unregister(&acpi_lid_notifier, nb);

}

EXPORT_SYMBOL(acpi_lid_notifier_unregister);



int acpi_lid_open(void)

{

	acpi_status status;

	unsigned long long state;



	status = acpi_evaluate_integer(lid_device->handle, "_LID", NULL,

				       &state);

	if (ACPI_FAILURE(status))

		return -ENODEV;



	return !!state;

}

EXPORT_SYMBOL(acpi_lid_open);



static int acpi_lid_send_state(struct acpi_device *device)

{

	struct acpi_button *button = acpi_driver_data(device);

	unsigned long long state;

	acpi_status status;

	int ret;



	status = acpi_evaluate_integer(device->handle, "_LID", NULL, &state);

	if (ACPI_FAILURE(status))
@@ -242,7 +272,12 @@ static int acpi_lid_send_state(struct acpi_device *device) 
	/* input layer checks if event is redundant */

	input_report_switch(button->input, SW_LID, !state);

	input_sync(button->input);

	return 0;



	ret = blocking_notifier_call_chain(&acpi_lid_notifier, state, device);

	if (ret == NOTIFY_DONE)

		ret = blocking_notifier_call_chain(&acpi_lid_notifier, state,

						   device);

	return ret;

}



static void acpi_button_notify(struct acpi_device *device, u32 event)
@@ -364,8 +399,14 @@ static int acpi_button_add(struct acpi_device *device) 
	error = input_register_device(input);

	if (error)

		goto err_remove_fs;

	if (button->type == ACPI_BUTTON_TYPE_LID)

	if (button->type == ACPI_BUTTON_TYPE_LID) {

		acpi_lid_send_state(device);

		/*

		 * This assumes there's only one lid device, or if there are

		 * more we only care about the last one...

		 */

		lid_device = device;

	}



	if (device->wakeup.flags.valid) {

		/* Button's GPE is run-wake GPE */

include/acpi/button.h

0 → 100644
+10 −0
Original line number Diff line number Diff line 
#ifndef ACPI_BUTTON_H

#define ACPI_BUTTON_H



#include <linux/notifier.h>



extern int acpi_lid_notifier_register(struct notifier_block *nb);

extern int acpi_lid_notifier_unregister(struct notifier_block *nb);

extern int acpi_lid_open(void);



#endif /* ACPI_BUTTON_H */

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