ACPI: support acpi_device_ops .notify methods

This patch adds support for ACPI device driver .notify() methods.  If
such a method is present, Linux/ACPI installs a handler for device
notifications (but not for system notifications such as Bus Check,
Device Check, etc).  When a device notification occurs, Linux/ACPI
passes it on to the driver's .notify() method.

In most cases, this removes the need for drivers to install their own
handlers for device-specific notifications.

For fixed hardware devices like some power and sleep buttons, there's
no notification value because there's no control method to execute a
Notify opcode.  When a fixed hardware device generates an event, we
handle it the same as a regular device notification, except we send
a ACPI_FIXED_HARDWARE_EVENT value.  This is outside the normal 0x0-0xff
range used by Notify opcodes.

Several drivers install their own handlers for system Bus Check and
Device Check notifications so they can support hot-plug.  This patch
doesn't affect that usage.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Reviewed-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 08ec60c8366a..a2228511d4be 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -95,6 +95,7 @@ typedef int (*acpi_op_suspend) (struct acpi_device * device,
 typedef int (*acpi_op_resume) (struct acpi_device * device);
 typedef int (*acpi_op_bind) (struct acpi_device * device);
 typedef int (*acpi_op_unbind) (struct acpi_device * device);
+typedef void (*acpi_op_notify) (struct acpi_device * device, u32 event);
 
 struct acpi_bus_ops {
 	u32 acpi_op_add:1;
@@ -110,6 +111,7 @@ struct acpi_device_ops {
 	acpi_op_resume resume;
 	acpi_op_bind bind;
 	acpi_op_unbind unbind;
+	acpi_op_notify notify;
 };
 
 struct acpi_driver {