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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: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
hifive-unleashed-5.1
Jesse Barnes 2009-09-10 15:28:02 -07:00 committed by Eric Anholt
parent af729a26cc
commit 7e12715ecc
2 changed files with 53 additions and 2 deletions
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45
drivers/acpi/button.c
View File

@ -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 */

10
include/acpi/button.h 100644
View File

@ -0,0 +1,10 @@
#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 */