[PATCH v2 1/2] iio: light: adjd_s311: move buffer on adjd_s311_data object

[PATCH v2 1/2] iio: light: adjd_s311: move buffer on adjd_s311_data object

[Alexandru Ardelean]

This change moves the entire buffer on the private adjd_s311_data type.
Since the device has 4 channels, it's not a big waste to just allocate the
maximum possible buffer and use only what's needed.

This is in contrast with free-ing and re-allocating the buffer on the
update_scan_mode hook.

Since the driver pushes buffer data with
iio_push_to_buffers_with_timestamp(), the buffer must also include a
64-bit buffer for the timestamp, for each sample-set.

With this change, the adjd_s311_update_scan_mode() is no longer needed.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
---

Changelog v1 -> v2:
* https://patchwork.kernel.org/project/linux-iio/patch/20210628135132.73682-1-aardelean@deviqon.com/
* split into 2 patches:
  - first patch move the buffer on the adjd_s311_data object (i.e. this
    patch)
  - second patch to do the conversion to devm_ functions

 drivers/iio/light/adjd_s311.c | 25 ++++++-------------------
 1 file changed, 6 insertions(+), 19 deletions(-)

diff --git a/drivers/iio/light/adjd_s311.c b/drivers/iio/light/adjd_s311.c
index 17dac8d0e11d..caf852554897 100644
--- a/drivers/iio/light/adjd_s311.c
+++ b/drivers/iio/light/adjd_s311.c
@@ -54,7 +54,10 @@
 
 struct adjd_s311_data {
 	struct i2c_client *client;
-	u16 *buffer;
+	struct {
+		s16 chans[4];
+		s64 ts __aligned(8);
+	} scan;
 };
 
 enum adjd_s311_channel_idx {
@@ -129,10 +132,10 @@ static irqreturn_t adjd_s311_trigger_handler(int irq, void *p)
 		if (ret < 0)
 			goto done;
 
-		data->buffer[j++] = ret & ADJD_S311_DATA_MASK;
+		data->scan.chans[j++] = ret & ADJD_S311_DATA_MASK;
 	}
 
-	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, time_ns);
+	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, time_ns);
 
 done:
 	iio_trigger_notify_done(indio_dev->trig);
@@ -225,23 +228,9 @@ static int adjd_s311_write_raw(struct iio_dev *indio_dev,
 	return -EINVAL;
 }
 
-static int adjd_s311_update_scan_mode(struct iio_dev *indio_dev,
-	const unsigned long *scan_mask)
-{
-	struct adjd_s311_data *data = iio_priv(indio_dev);
-
-	kfree(data->buffer);
-	data->buffer = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
-	if (data->buffer == NULL)
-		return -ENOMEM;
-
-	return 0;
-}
-
 static const struct iio_info adjd_s311_info = {
 	.read_raw = adjd_s311_read_raw,
 	.write_raw = adjd_s311_write_raw,
-	.update_scan_mode = adjd_s311_update_scan_mode,
 };
 
 static int adjd_s311_probe(struct i2c_client *client,
@@ -286,11 +275,9 @@ static int adjd_s311_probe(struct i2c_client *client,
 static int adjd_s311_remove(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
-	struct adjd_s311_data *data = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
 	iio_triggered_buffer_cleanup(indio_dev);
-	kfree(data->buffer);
 
 	return 0;
 }
-- 
2.31.1

[PATCH v2 2/2] iio: light: adjd_s311: convert probe to device-managed functions

[Alexandru Ardelean]

Now that the driver's buffer is stored on the adjd_s311_data private
object, the driver is a simple conversion to use only device-managed
functions in the probe.

The iio_triggered_buffer_setup() and iio_device_register() functions are
the only ones needing conversion.
And i2c_set_clientdata() is no longer required.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
---
 drivers/iio/light/adjd_s311.c | 28 +++-------------------------
 1 file changed, 3 insertions(+), 25 deletions(-)

diff --git a/drivers/iio/light/adjd_s311.c b/drivers/iio/light/adjd_s311.c
index caf852554897..6b33975c8d73 100644
--- a/drivers/iio/light/adjd_s311.c
+++ b/drivers/iio/light/adjd_s311.c
@@ -245,7 +245,6 @@ static int adjd_s311_probe(struct i2c_client *client,
 		return -ENOMEM;
 
 	data = iio_priv(indio_dev);
-	i2c_set_clientdata(client, indio_dev);
 	data->client = client;
 
 	indio_dev->info = &adjd_s311_info;
@@ -254,32 +253,12 @@ static int adjd_s311_probe(struct i2c_client *client,
 	indio_dev->num_channels = ARRAY_SIZE(adjd_s311_channels);
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
-	err = iio_triggered_buffer_setup(indio_dev, NULL,
-		adjd_s311_trigger_handler, NULL);
+	err = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
+					      adjd_s311_trigger_handler, NULL);
 	if (err < 0)
 		return err;
 
-	err = iio_device_register(indio_dev);
-	if (err)
-		goto exit_unreg_buffer;
-
-	dev_info(&client->dev, "ADJD-S311 color sensor registered\n");
-
-	return 0;
-
-exit_unreg_buffer:
-	iio_triggered_buffer_cleanup(indio_dev);
-	return err;
-}
-
-static int adjd_s311_remove(struct i2c_client *client)
-{
-	struct iio_dev *indio_dev = i2c_get_clientdata(client);
-
-	iio_device_unregister(indio_dev);
-	iio_triggered_buffer_cleanup(indio_dev);
-
-	return 0;
+	return devm_iio_device_register(&client->dev, indio_dev);
 }
 
 static const struct i2c_device_id adjd_s311_id[] = {
@@ -293,7 +272,6 @@ static struct i2c_driver adjd_s311_driver = {
 		.name	= ADJD_S311_DRV_NAME,
 	},
 	.probe		= adjd_s311_probe,
-	.remove		= adjd_s311_remove,
 	.id_table	= adjd_s311_id,
 };
 module_i2c_driver(adjd_s311_driver);
-- 
2.31.1