[PATCH v2 2/3] iio: buffer: use struct iio_scan_type to simplify code

From: David Lechner
Date: Fri May 24 2024 - 16:18:47 EST


By using struct iio_scan_type, we can simplify the code by removing
lots of duplicate pointer dereferences. This make the code a bit easier
to read.

This also prepares for a future where channels may have more than one
scan_type.

Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
---
v2 changes:
* fixed spelling of dereferences in commit message
---
drivers/iio/industrialio-buffer.c | 48 +++++++++++++++++++++++----------------
1 file changed, 28 insertions(+), 20 deletions(-)

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index cec58a604d73..08103a9e77f7 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -366,7 +366,8 @@ static ssize_t iio_show_fixed_type(struct device *dev,
char *buf)
{
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
- u8 type = this_attr->c->scan_type.endianness;
+ const struct iio_scan_type *scan_type = &this_attr->c->scan_type;
+ u8 type = scan_type->endianness;

if (type == IIO_CPU) {
#ifdef __LITTLE_ENDIAN
@@ -375,21 +376,21 @@ static ssize_t iio_show_fixed_type(struct device *dev,
type = IIO_BE;
#endif
}
- if (this_attr->c->scan_type.repeat > 1)
+ if (scan_type->repeat > 1)
return sysfs_emit(buf, "%s:%c%d/%dX%d>>%u\n",
iio_endian_prefix[type],
- this_attr->c->scan_type.sign,
- this_attr->c->scan_type.realbits,
- this_attr->c->scan_type.storagebits,
- this_attr->c->scan_type.repeat,
- this_attr->c->scan_type.shift);
+ scan_type->sign,
+ scan_type->realbits,
+ scan_type->storagebits,
+ scan_type->repeat,
+ scan_type->shift);
else
return sysfs_emit(buf, "%s:%c%d/%d>>%u\n",
iio_endian_prefix[type],
- this_attr->c->scan_type.sign,
- this_attr->c->scan_type.realbits,
- this_attr->c->scan_type.storagebits,
- this_attr->c->scan_type.shift);
+ scan_type->sign,
+ scan_type->realbits,
+ scan_type->storagebits,
+ scan_type->shift);
}

static ssize_t iio_scan_el_show(struct device *dev,
@@ -694,12 +695,16 @@ static unsigned int iio_storage_bytes_for_si(struct iio_dev *indio_dev,
unsigned int scan_index)
{
const struct iio_chan_spec *ch;
+ const struct iio_scan_type *scan_type;
unsigned int bytes;

ch = iio_find_channel_from_si(indio_dev, scan_index);
- bytes = ch->scan_type.storagebits / 8;
- if (ch->scan_type.repeat > 1)
- bytes *= ch->scan_type.repeat;
+ scan_type = &ch->scan_type;
+ bytes = scan_type->storagebits / 8;
+
+ if (scan_type->repeat > 1)
+ bytes *= scan_type->repeat;
+
return bytes;
}

@@ -1616,18 +1621,21 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
if (channels) {
/* new magic */
for (i = 0; i < indio_dev->num_channels; i++) {
+ const struct iio_scan_type *scan_type;
+
if (channels[i].scan_index < 0)
continue;

+ scan_type = &channels[i].scan_type;
+
/* Verify that sample bits fit into storage */
- if (channels[i].scan_type.storagebits <
- channels[i].scan_type.realbits +
- channels[i].scan_type.shift) {
+ if (scan_type->storagebits <
+ scan_type->realbits + scan_type->shift) {
dev_err(&indio_dev->dev,
"Channel %d storagebits (%d) < shifted realbits (%d + %d)\n",
- i, channels[i].scan_type.storagebits,
- channels[i].scan_type.realbits,
- channels[i].scan_type.shift);
+ i, scan_type->storagebits,
+ scan_type->realbits,
+ scan_type->shift);
ret = -EINVAL;
goto error_cleanup_dynamic;
}

--
2.45.1