Commit 46ec8598 authored by Bjorn Helgaas's avatar Bjorn Helgaas Committed by Len Brown
Browse files

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: default avatarBjorn Helgaas <bjorn.helgaas@hp.com>
Reviewed-by: default avatarAlex Chiang <achiang@hp.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 478c6a43

drivers/acpi/scan.c

+71 −0
Original line number Diff line number Diff line
@@ -359,6 +359,61 @@ static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env) 
	return 0;

}



static void acpi_device_notify(acpi_handle handle, u32 event, void *data)

{

	struct acpi_device *device = data;



	device->driver->ops.notify(device, event);

}



static acpi_status acpi_device_notify_fixed(void *data)

{

	struct acpi_device *device = data;



	acpi_device_notify(device->handle, ACPI_FIXED_HARDWARE_EVENT, device);

	return AE_OK;

}



static int acpi_device_install_notify_handler(struct acpi_device *device)

{

	acpi_status status;

	char *hid;



	hid = acpi_device_hid(device);

	if (!strcmp(hid, ACPI_BUTTON_HID_POWERF))

		status =

		    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,

						     acpi_device_notify_fixed,

						     device);

	else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEPF))

		status =

		    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,

						     acpi_device_notify_fixed,

						     device);

	else

		status = acpi_install_notify_handler(device->handle,

						     ACPI_DEVICE_NOTIFY,

						     acpi_device_notify,

						     device);



	if (ACPI_FAILURE(status))

		return -EINVAL;

	return 0;

}



static void acpi_device_remove_notify_handler(struct acpi_device *device)

{

	if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_POWERF))

		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,

						acpi_device_notify_fixed);

	else if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_SLEEPF))

		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,

						acpi_device_notify_fixed);

	else

		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,

					   acpi_device_notify);

}



static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);

static int acpi_start_single_object(struct acpi_device *);

static int acpi_device_probe(struct device * dev)
@@ -371,6 +426,20 @@ static int acpi_device_probe(struct device * dev) 
	if (!ret) {

		if (acpi_dev->bus_ops.acpi_op_start)

			acpi_start_single_object(acpi_dev);



		if (acpi_drv->ops.notify) {

			ret = acpi_device_install_notify_handler(acpi_dev);

			if (ret) {

				if (acpi_drv->ops.stop)

					acpi_drv->ops.stop(acpi_dev,

						   acpi_dev->removal_type);

				if (acpi_drv->ops.remove)

					acpi_drv->ops.remove(acpi_dev,

						     acpi_dev->removal_type);

				return ret;

			}

		}



		ACPI_DEBUG_PRINT((ACPI_DB_INFO,

			"Found driver [%s] for device [%s]\n",

			acpi_drv->name, acpi_dev->pnp.bus_id));
@@ -385,6 +454,8 @@ static int acpi_device_remove(struct device * dev) 
	struct acpi_driver *acpi_drv = acpi_dev->driver;



	if (acpi_drv) {

		if (acpi_drv->ops.notify)

			acpi_device_remove_notify_handler(acpi_dev);

		if (acpi_drv->ops.stop)

			acpi_drv->ops.stop(acpi_dev, acpi_dev->removal_type);

		if (acpi_drv->ops.remove)

include/acpi/acpi_bus.h

+2 −0
Original line number Diff line number Diff line
@@ -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 {

include/acpi/acpi_drivers.h

+10 −0
Original line number Diff line number Diff line
@@ -67,6 +67,16 @@ 
#define ACPI_BAY_HID			"LNXIOBAY"

#define ACPI_DOCK_HID			"LNXDOCK"



/*

 * For fixed hardware buttons, we fabricate acpi_devices with HID

 * ACPI_BUTTON_HID_POWERF or ACPI_BUTTON_HID_SLEEPF.  Fixed hardware

 * signals only an event; it doesn't supply a notification value.

 * To allow drivers to treat notifications from fixed hardware the

 * same as those from real devices, we turn the events into this

 * notification value.

 */

#define ACPI_FIXED_HARDWARE_EVENT	0x100



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

                                       PCI

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

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