[PATCH] staging: iio: ad5933: merge ring init function into probe function

[Alexandru Ardelean <alexandru.ardelean@analog.com>]

This is a small cleanup of the driver's init code.
It does not fix anything.

The `devm_iio_kfifo_allocate()` function is used instead of
`iio_kfifo_allocate()`.  This removes the need for explicit deallocation of
the driver's iio_buffer, which will now be handled via
`iio_device_unregister()`.

The `setup_ops` assignment has been moved into the `ad5933_probe()` call,
since it's a one-liner.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---

Note: this change is based on top of `fixes-togreg-post-rc1` branch which
contains commit (7d2b8e6aaf9: staging: iio: ad5933: switch buffer mode to
software)

 drivers/staging/iio/impedance-analyzer/ad5933.c | 35 +++++++------------------
 1 file changed, 10 insertions(+), 25 deletions(-)

diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c b/drivers/staging/iio/impedance-analyzer/ad5933.c
index 3bcf49466361..1cab67b3a81e 100644
--- a/drivers/staging/iio/impedance-analyzer/ad5933.c
+++ b/drivers/staging/iio/impedance-analyzer/ad5933.c
@@ -635,22 +635,6 @@ static const struct iio_buffer_setup_ops ad5933_ring_setup_ops = {
 	.postdisable = ad5933_ring_postdisable,
 };
 
-static int ad5933_register_ring_funcs_and_init(struct iio_dev *indio_dev)
-{
-	struct iio_buffer *buffer;
-
-	buffer = iio_kfifo_allocate();
-	if (!buffer)
-		return -ENOMEM;
-
-	iio_device_attach_buffer(indio_dev, buffer);
-
-	/* Ring buffer functions - here trigger setup related */
-	indio_dev->setup_ops = &ad5933_ring_setup_ops;
-
-	return 0;
-}
-
 static void ad5933_work(struct work_struct *work)
 {
 	struct ad5933_state *st = container_of(work,
@@ -714,12 +698,19 @@ static int ad5933_probe(struct i2c_client *client,
 	int ret, voltage_uv = 0;
 	struct ad5933_platform_data *pdata = dev_get_platdata(&client->dev);
 	struct ad5933_state *st;
+	struct iio_buffer *buffer;
 	struct iio_dev *indio_dev;
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
 	if (!indio_dev)
 		return -ENOMEM;
 
+	buffer = devm_iio_kfifo_allocate(&client->dev);
+	if (!buffer)
+		return -ENOMEM;
+
+	iio_device_attach_buffer(indio_dev, buffer);
+
 	st = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 	st->client = client;
@@ -763,23 +754,18 @@ static int ad5933_probe(struct i2c_client *client,
 	indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE);
 	indio_dev->channels = ad5933_channels;
 	indio_dev->num_channels = ARRAY_SIZE(ad5933_channels);
-
-	ret = ad5933_register_ring_funcs_and_init(indio_dev);
-	if (ret)
-		goto error_disable_reg;
+	indio_dev->setup_ops = &ad5933_ring_setup_ops;
 
 	ret = ad5933_setup(st);
 	if (ret)
-		goto error_unreg_ring;
+		goto error_disable_reg;
 
 	ret = iio_device_register(indio_dev);
 	if (ret)
-		goto error_unreg_ring;
+		goto error_disable_reg;
 
 	return 0;
 
-error_unreg_ring:
-	iio_kfifo_free(indio_dev->buffer);
 error_disable_reg:
 	regulator_disable(st->reg);
 
@@ -792,7 +778,6 @@ static int ad5933_remove(struct i2c_client *client)
 	struct ad5933_state *st = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
-	iio_kfifo_free(indio_dev->buffer);
 	regulator_disable(st->reg);
 
 	return 0;
-- 
2.14.1