host1x: Convert to bus methods

The callbacks .probe(), .remove() and .shutdown() for device_drivers
should go away. So migrate to bus methods. There are two differences
that need addressing:

 - The bus remove callback returns void while the driver remove callback
   returns int (the actual value is ignored by the core).
 - The bus shutdown callback is also called for unbound devices, so an
   additional check for dev->driver != NULL is needed.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # tegra20 tegra-video
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/dd55d034c68953268ea416aa5c13e41b158fcbb4.1765355236.git.u.kleine-koenig@baylibre.com

Author: ukleinek

drivers/gpu/host1x/bus.c

@@ -346,6 +346,36 @@ static int host1x_device_uevent(const struct device *dev,
 	return 0;
 }
 
+static int host1x_device_probe(struct device *dev)
+{
+	struct host1x_driver *driver = to_host1x_driver(dev->driver);
+	struct host1x_device *device = to_host1x_device(dev);
+
+	if (driver->probe)
+		return driver->probe(device);
+
+	return 0;
+}
+
+static void host1x_device_remove(struct device *dev)
+{
+	struct host1x_driver *driver = to_host1x_driver(dev->driver);
+	struct host1x_device *device = to_host1x_device(dev);
+
+	if (driver->remove)
+		driver->remove(device);
+}
+
+static void host1x_device_shutdown(struct device *dev)
+{
+	struct host1x_driver *driver = to_host1x_driver(dev->driver);
+	struct host1x_device *device = to_host1x_device(dev);
+
+	if (dev->driver && driver->shutdown)
+		driver->shutdown(device);
+}
+
+
 static const struct dev_pm_ops host1x_device_pm_ops = {
 	.suspend = pm_generic_suspend,
 	.resume = pm_generic_resume,
@@ -359,6 +389,9 @@ const struct bus_type host1x_bus_type = {
 	.name = "host1x",
 	.match = host1x_device_match,
 	.uevent = host1x_device_uevent,
+	.probe = host1x_device_probe,
+	.remove = host1x_device_remove,
+	.shutdown = host1x_device_shutdown,
 	.pm = &host1x_device_pm_ops,
 };
 
@@ -623,37 +656,6 @@ int host1x_unregister(struct host1x *host1x)
 	return 0;
 }
 
-static int host1x_device_probe(struct device *dev)
-{
-	struct host1x_driver *driver = to_host1x_driver(dev->driver);
-	struct host1x_device *device = to_host1x_device(dev);
-
-	if (driver->probe)
-		return driver->probe(device);
-
-	return 0;
-}
-
-static int host1x_device_remove(struct device *dev)
-{
-	struct host1x_driver *driver = to_host1x_driver(dev->driver);
-	struct host1x_device *device = to_host1x_device(dev);
-
-	if (driver->remove)
-		driver->remove(device);
-
-	return 0;
-}
-
-static void host1x_device_shutdown(struct device *dev)
-{
-	struct host1x_driver *driver = to_host1x_driver(dev->driver);
-	struct host1x_device *device = to_host1x_device(dev);
-
-	if (driver->shutdown)
-		driver->shutdown(device);
-}
-
 /**
  * host1x_driver_register_full() - register a host1x driver
  * @driver: host1x driver
@@ -684,9 +686,6 @@ int host1x_driver_register_full(struct host1x_driver *driver,
 
 	driver->driver.bus = &host1x_bus_type;
 	driver->driver.owner = owner;
-	driver->driver.probe = host1x_device_probe;
-	driver->driver.remove = host1x_device_remove;
-	driver->driver.shutdown = host1x_device_shutdown;
 
 	return driver_register(&driver->driver);
 }