media: v4l2-core: introduce a helper to unregister a i2c subdev

Introduce a new video4linux2 i2c helper, to unregister a subdev.
This allows to get rid of yet another ifdef.

Signed-off-by: Ezequiel Garcia <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
[[e-mail]: fix checkpatch warning]
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/v4l2-core/v4l2-device.c

···
 #include <linux/types.h>
 #include <linux/ioctl.h>
 #include <linux/module.h>
-#include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/videodev2.h>
 #include <media/v4l2-device.h>
···
 	/* Unregister subdevs */
 	list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
 		v4l2_device_unregister_subdev(sd);
-#if IS_ENABLED(CONFIG_I2C)
-		if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
-			struct i2c_client *client = v4l2_get_subdevdata(sd);
-
-			/*
-			 * We need to unregister the i2c client
-			 * explicitly. We cannot rely on
-			 * i2c_del_adapter to always unregister
-			 * clients for us, since if the i2c bus is a
-			 * platform bus, then it is never deleted.
-			 *
-			 * Device tree or ACPI based devices must not
-			 * be unregistered as they have not been
-			 * registered by us, and would not be
-			 * re-created by just probing the V4L2 driver.
-			 */
-			if (client &&
-			    !client->dev.of_node && !client->dev.fwnode)
-				i2c_unregister_device(client);
-			continue;
-		}
-#endif
+		if (sd->flags & V4L2_SUBDEV_FL_IS_I2C)
+			v4l2_i2c_subdev_unregister(sd);
 		else if (sd->flags & V4L2_SUBDEV_FL_IS_SPI)
 			v4l2_spi_subdev_unregister(sd);
 	}

drivers/media/v4l2-core/v4l2-i2c.c

···
 #include <media/v4l2-common.h>
 #include <media/v4l2-device.h>
 
+void v4l2_i2c_subdev_unregister(struct v4l2_subdev *sd)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	/*
+	 * We need to unregister the i2c client
+	 * explicitly. We cannot rely on
+	 * i2c_del_adapter to always unregister
+	 * clients for us, since if the i2c bus is a
+	 * platform bus, then it is never deleted.
+	 *
+	 * Device tree or ACPI based devices must not
+	 * be unregistered as they have not been
+	 * registered by us, and would not be
+	 * re-created by just probing the V4L2 driver.
+	 */
+	if (client && !client->dev.of_node && !client->dev.fwnode)
+		i2c_unregister_device(client);
+}
+
 void v4l2_i2c_subdev_set_name(struct v4l2_subdev *sd, struct i2c_client *client,
 			      const char *devname, const char *postfix)
 {

include/media/v4l2-common.h

···
  */
 const unsigned short *v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type);
 
+/**
+ * v4l2_i2c_subdev_unregister - Unregister a v4l2_subdev
+ *
+ * @sd: pointer to &struct v4l2_subdev
+ */
+void v4l2_i2c_subdev_unregister(struct v4l2_subdev *sd);
+
 #else
 
 static inline struct v4l2_subdev *
···
 {
 	return NULL;
 }
+
+static inline void v4l2_i2c_subdev_unregister(struct v4l2_subdev *sd)
+{}
 
 #endif