iio: core: move @flags from struct iio_dev to struct iio_dev_opaque

No reason any driver should ever need access to this field, so hide it.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210426174911.397061-9-jic23@kernel.org

drivers/iio/industrialio-core.c

@@ -1720,7 +1720,7 @@ static int iio_chrdev_open(struct inode *inode, struct file *filp)
 	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
 	struct iio_dev_buffer_pair *ib;
 
-	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
+	if (test_and_set_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags))
 		return -EBUSY;
 
 	iio_device_get(indio_dev);
@@ -1728,7 +1728,7 @@ static int iio_chrdev_open(struct inode *inode, struct file *filp)
 	ib = kmalloc(sizeof(*ib), GFP_KERNEL);
 	if (!ib) {
 		iio_device_put(indio_dev);
-		clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
+		clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
 		return -ENOMEM;
 	}
 
@@ -1754,7 +1754,7 @@ static int iio_chrdev_release(struct inode *inode, struct file *filp)
 		container_of(inode->i_cdev, struct iio_dev_opaque, chrdev);
 	struct iio_dev *indio_dev = &iio_dev_opaque->indio_dev;
 	kfree(ib);
-	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
+	clear_bit(IIO_BUSY_BIT_POS, &iio_dev_opaque->flags);
 	iio_device_put(indio_dev);
 
 	return 0;

include/linux/iio/iio-opaque.h

@@ -25,6 +25,7 @@
  * @legacy_buffer_group:	attribute group for legacy buffer attributes group
  * @scan_index_timestamp:	cache of the index to the timestamp
  * @chrdev:			associated character device
+ * @flags:			file ops related flags including busy flag.
  * @debugfs_dentry:		device specific debugfs dentry
  * @cached_reg_addr:		cached register address for debugfs reads
  * @read_buf:			read buffer to be used for the initial reg read
@@ -51,6 +52,7 @@ struct iio_dev_opaque {
 
 	unsigned int			scan_index_timestamp;
 	struct cdev			chrdev;
+	unsigned long			flags;
 
 #if defined(CONFIG_DEBUG_FS)
 	struct dentry			*debugfs_dentry;

include/linux/iio/iio.h

@@ -512,7 +512,6 @@ struct iio_buffer_setup_ops {
  * @clock_id:		[INTERN] timestamping clock posix identifier
  * @setup_ops:		[DRIVER] callbacks to call before and after buffer
  *			enable/disable
- * @flags:		[INTERN] file ops related flags including busy flag.
  * @priv:		[DRIVER] reference to driver's private information
  *			**MUST** be accessed **ONLY** via iio_priv() helper
  */
@@ -542,7 +541,6 @@ struct iio_dev {
 	clockid_t			clock_id;
 	const struct iio_buffer_setup_ops	*setup_ops;
 
-	unsigned long			flags;
 	void				*priv;
 };