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

From: Alexandru Ardelean
Date: Mon Jul 05 2021 - 03:15:12 EST


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@xxxxxxxxxxx>
---

Changelog v1 -> v2:
* https://patchwork.kernel.org/project/linux-iio/patch/20210628135132.73682-1-aardelean@xxxxxxxxxxx/
* 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