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authorJesse Barnes <jbarnes@virtuousgeek.org>2009-09-11 02:28:02 +0400
committerEric Anholt <eric@anholt.net>2009-09-11 03:09:11 +0400
commit7e12715ecc47a8a59154afe2746e48998225bb69 (patch)
tree308e53b58027772bd114585f57c4180eb89239a7 /drivers/acpi/button.c
parentaf729a26ccc3ff9ad834a5e96f455aab20f176cd (diff)
downloadlinux-7e12715ecc47a8a59154afe2746e48998225bb69.tar.xz
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>
Diffstat (limited to 'drivers/acpi/button.c')
-rw-r--r--drivers/acpi/button.c45
1 files changed, 43 insertions, 2 deletions
diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 9195deba9d94..ebb593e9c380 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 */