diff options
| author | Jesse Barnes <jbarnes@virtuousgeek.org> | 2009-09-10 15:28:02 -0700 |
|---|---|---|
| committer | Eric Anholt <eric@anholt.net> | 2009-09-10 16:09:11 -0700 |
| commit | 7e12715ecc47a8a59154afe2746e48998225bb69 (patch) | |
| tree | 308e53b58027772bd114585f57c4180eb89239a7 | |
| parent | af729a26ccc3ff9ad834a5e96f455aab20f176cd (diff) | |
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>
| -rw-r--r-- | drivers/acpi/button.c | 45 | ||||
| -rw-r--r-- | include/acpi/button.h | 10 |
2 files changed, 53 insertions, 2 deletions
diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c index 9195deba9d9..ebb593e9c38 100644 --- a/drivers/acpi/button.c +++ b/drivers/acpi/button.c @@ -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 */ diff --git a/include/acpi/button.h b/include/acpi/button.h new file mode 100644 index 00000000000..bb643a79d65 --- /dev/null +++ b/include/acpi/button.h @@ -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 */ |