ACPI: bus: Drop driver member of struct acpi_device

struct acpi_device::driver tracks the same information as the driver
member of struct acpi_device::dev.

Fix all users of the former to use the latter and drop the redundant
data from struct acpi_device.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/bus.c

@@ -465,7 +465,6 @@ static void acpi_bus_osc_negotiate_usb_control(void)
 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
 {
 	struct acpi_device *adev;
-	struct acpi_driver *driver;
 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 	bool hotplug_event = false;
 
@@ -517,10 +516,13 @@ static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
 	if (!adev)
 		goto err;
 
-	driver = adev->driver;
-	if (driver && driver->ops.notify &&
-	    (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
-		driver->ops.notify(adev, type);
+	if (adev->dev.driver) {
+		struct acpi_driver *driver = to_acpi_driver(adev->dev.driver);
+
+		if (driver && driver->ops.notify &&
+		    (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
+			driver->ops.notify(adev, type);
+	}
 
 	if (!hotplug_event) {
 		acpi_bus_put_acpi_device(adev);
@@ -539,8 +541,9 @@ static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
 static void acpi_notify_device(acpi_handle handle, u32 event, void *data)
 {
 	struct acpi_device *device = data;
+	struct acpi_driver *acpi_drv = to_acpi_driver(device->dev.driver);
 
-	device->driver->ops.notify(device, event);
+	acpi_drv->ops.notify(device, event);
 }
 
 static void acpi_notify_device_fixed(void *data)
@@ -1033,8 +1036,6 @@ static int acpi_device_probe(struct device *dev)
 	if (ret)
 		return ret;
 
-	acpi_dev->driver = acpi_drv;
-
 	pr_debug("Driver [%s] successfully bound to device [%s]\n",
 		 acpi_drv->name, acpi_dev->pnp.bus_id);
 
@@ -1044,7 +1045,6 @@ static int acpi_device_probe(struct device *dev)
 			if (acpi_drv->ops.remove)
 				acpi_drv->ops.remove(acpi_dev);
 
-			acpi_dev->driver = NULL;
 			acpi_dev->driver_data = NULL;
 			return ret;
 		}
@@ -1060,7 +1060,7 @@ static int acpi_device_probe(struct device *dev)
 static void acpi_device_remove(struct device *dev)
 {
 	struct acpi_device *acpi_dev = to_acpi_device(dev);
-	struct acpi_driver *acpi_drv = acpi_dev->driver;
+	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
 
 	if (acpi_drv->ops.notify)
 		acpi_device_remove_notify_handler(acpi_dev);
@@ -1068,7 +1068,6 @@ static void acpi_device_remove(struct device *dev)
 	if (acpi_drv->ops.remove)
 		acpi_drv->ops.remove(acpi_dev);
 
-	acpi_dev->driver = NULL;
 	acpi_dev->driver_data = NULL;
 
 	put_device(dev);

drivers/acpi/device_sysfs.c

@@ -376,7 +376,7 @@ eject_store(struct device *d, struct device_attribute *attr,
 		return -EINVAL;
 
 	if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
-	    && !acpi_device->driver)
+	    && !d->driver)
 		return -ENODEV;
 
 	status = acpi_get_type(acpi_device->handle, &not_used);

include/acpi/acpi_bus.h

@@ -379,7 +379,6 @@ struct acpi_device {
 	struct acpi_device_data data;
 	struct acpi_scan_handler *handler;
 	struct acpi_hotplug_context *hp;
-	struct acpi_driver *driver;
 	const struct acpi_gpio_mapping *driver_gpios;
 	void *driver_data;
 	struct device dev;