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>

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>
Bjorn Helgaas · Len Brown
1 parent 478c6a43fc
Showing 3 changed files with 83 additions and 0 deletions Side-by-side Diff
drivers/acpi/scan.c
include/acpi/acpi_bus.h
include/acpi/acpi_drivers.h
@@ -359,6 +359,61 @@
 	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 @@
 	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 @@
 	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)
@@ -95,6 +95,7 @@
 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 @@
 	acpi_op_resume resume;
 	acpi_op_bind bind;
 	acpi_op_unbind unbind;
+	acpi_op_notify notify;
 };
  
 struct acpi_driver {
@@ -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
    -------------------------------------------------------------------------- */
...	...	@@ -359,6 +359,61 @@
359	359	return 0;
360	360	}
361	361
	362	+static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
	363	+{
	364	+ struct acpi_device *device = data;
	365	+
	366	+ device->driver->ops.notify(device, event);
	367	+}
	368	+
	369	+static acpi_status acpi_device_notify_fixed(void *data)
	370	+{
	371	+ struct acpi_device *device = data;
	372	+
	373	+ acpi_device_notify(device->handle, ACPI_FIXED_HARDWARE_EVENT, device);
	374	+ return AE_OK;
	375	+}
	376	+
	377	+static int acpi_device_install_notify_handler(struct acpi_device *device)
	378	+{
	379	+ acpi_status status;
	380	+ char *hid;
	381	+
	382	+ hid = acpi_device_hid(device);
	383	+ if (!strcmp(hid, ACPI_BUTTON_HID_POWERF))
	384	+ status =
	385	+ acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
	386	+ acpi_device_notify_fixed,
	387	+ device);
	388	+ else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEPF))
	389	+ status =
	390	+ acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
	391	+ acpi_device_notify_fixed,
	392	+ device);
	393	+ else
	394	+ status = acpi_install_notify_handler(device->handle,
	395	+ ACPI_DEVICE_NOTIFY,
	396	+ acpi_device_notify,
	397	+ device);
	398	+
	399	+ if (ACPI_FAILURE(status))
	400	+ return -EINVAL;
	401	+ return 0;
	402	+}
	403	+
	404	+static void acpi_device_remove_notify_handler(struct acpi_device *device)
	405	+{
	406	+ if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_POWERF))
	407	+ acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
	408	+ acpi_device_notify_fixed);
	409	+ else if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_SLEEPF))
	410	+ acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
	411	+ acpi_device_notify_fixed);
	412	+ else
	413	+ acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
	414	+ acpi_device_notify);
	415	+}
	416	+
362	417	static int acpi_bus_driver_init(struct acpi_device , struct acpi_driver );
363	418	static int acpi_start_single_object(struct acpi_device *);
364	419	static int acpi_device_probe(struct device * dev)
...	...	@@ -371,6 +426,20 @@
371	426	if (!ret) {
372	427	if (acpi_dev->bus_ops.acpi_op_start)
373	428	acpi_start_single_object(acpi_dev);
	429	+
	430	+ if (acpi_drv->ops.notify) {
	431	+ ret = acpi_device_install_notify_handler(acpi_dev);
	432	+ if (ret) {
	433	+ if (acpi_drv->ops.stop)
	434	+ acpi_drv->ops.stop(acpi_dev,
	435	+ acpi_dev->removal_type);
	436	+ if (acpi_drv->ops.remove)
	437	+ acpi_drv->ops.remove(acpi_dev,
	438	+ acpi_dev->removal_type);
	439	+ return ret;
	440	+ }
	441	+ }
	442	+
374	443	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
375	444	"Found driver [%s] for device [%s]\n",
376	445	acpi_drv->name, acpi_dev->pnp.bus_id));
...	...	@@ -385,6 +454,8 @@
385	454	struct acpi_driver *acpi_drv = acpi_dev->driver;
386	455
387	456	if (acpi_drv) {
	457	+ if (acpi_drv->ops.notify)
	458	+ acpi_device_remove_notify_handler(acpi_dev);
388	459	if (acpi_drv->ops.stop)
389	460	acpi_drv->ops.stop(acpi_dev, acpi_dev->removal_type);
390	461	if (acpi_drv->ops.remove)
...	...	@@ -95,6 +95,7 @@
95	95	typedef int (acpi_op_resume) (struct acpi_device device);
96	96	typedef int (acpi_op_bind) (struct acpi_device device);
97	97	typedef int (acpi_op_unbind) (struct acpi_device device);
	98	+typedef void (acpi_op_notify) (struct acpi_device device, u32 event);
98	99
99	100	struct acpi_bus_ops {
100	101	u32 acpi_op_add:1;
...	...	@@ -110,6 +111,7 @@
110	111	acpi_op_resume resume;
111	112	acpi_op_bind bind;
112	113	acpi_op_unbind unbind;
	114	+ acpi_op_notify notify;
113	115	};
114	116
115	117	struct acpi_driver {
...	...	@@ -67,6 +67,16 @@
67	67	#define ACPI_BAY_HID "LNXIOBAY"
68	68	#define ACPI_DOCK_HID "LNXDOCK"
69	69
	70	+/*
	71	+ * For fixed hardware buttons, we fabricate acpi_devices with HID
	72	+ * ACPI_BUTTON_HID_POWERF or ACPI_BUTTON_HID_SLEEPF. Fixed hardware
	73	+ * signals only an event; it doesn't supply a notification value.
	74	+ * To allow drivers to treat notifications from fixed hardware the
	75	+ * same as those from real devices, we turn the events into this
	76	+ * notification value.
	77	+ */
	78	+#define ACPI_FIXED_HARDWARE_EVENT 0x100
	79	+
70	80	/* --------------------------------------------------------------------------
71	81	PCI
72	82	-------------------------------------------------------------------------- */