[PATCH v3 05/12] iio: adc: ad_sigma_delta: use BITS_TO_BYTES() macro

David Lechner
2025-07-01T21:39:36Z

Use the BITS_TO_BYTES() macro instead of dividing by 8 to convert bits
to bytes.

This makes it more obvious what unit conversion is taking place.

In one instance, we also avoid the temporary assignment to a variable
as it was confusing that reg_size was being used with two different
units (bits and bytes).

scan_type is factored out to reduce line wrapping.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
drivers/iio/adc/ad_sigma_delta.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c
index dd15c357d1494bf5718e50e50a514cb4d4556f2b..f91f7ae6dfca05cf3ae632a5f19990f3d153b706 100644
--- a/drivers/iio/adc/ad_sigma_delta.c
+++ b/drivers/iio/adc/ad_sigma_delta.c
@@ -7,6 +7,7 @@
*/

#include <linux/align.h>
+#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
@@ -190,7 +191,7 @@ int ad_sd_reset(struct ad_sigma_delta *sigma_delta)
u8 *buf;
int ret;

- size = DIV_ROUND_UP(reset_length, 8);
+ size = BITS_TO_BYTES(reset_length);
buf = kcalloc(size, sizeof(*buf), GFP_KERNEL);
if (!buf)
return -ENOMEM;
@@ -419,7 +420,7 @@ int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
data_reg = AD_SD_REG_DATA;

ret = ad_sd_read_reg(sigma_delta, data_reg,
- DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8),
+ BITS_TO_BYTES(chan->scan_type.realbits + chan->scan_type.shift),
&raw_sample);

out:
@@ -453,6 +454,7 @@ EXPORT_SYMBOL_NS_GPL(ad_sigma_delta_single_conversion, "IIO_AD_SIGMA_DELTA");
static int ad_sd_buffer_postenable(struct iio_dev *indio_dev)
{
struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
+ const struct iio_scan_type *scan_type = &indio_dev->channels[0].scan_type;
unsigned int i, slot, samples_buf_size;
unsigned int channel;
u8 *samples_buf;
@@ -488,7 +490,7 @@ static int ad_sd_buffer_postenable(struct iio_dev *indio_dev)
return ret;
}

- samples_buf_size = ALIGN(slot * indio_dev->channels[0].scan_type.storagebits / 8,
+ samples_buf_size = ALIGN(slot * BITS_TO_BYTES(scan_type->storagebits),
sizeof(s64));
samples_buf_size += sizeof(s64);
samples_buf = devm_krealloc(&sigma_delta->spi->dev, sigma_delta->samples_buf,
@@ -544,6 +546,7 @@ static irqreturn_t ad_sd_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
+ const struct iio_scan_type *scan_type = &indio_dev->channels[0].scan_type;
struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
u8 *data = sigma_delta->rx_buf;
unsigned int transfer_size;
@@ -553,9 +556,7 @@ static irqreturn_t ad_sd_trigger_handler(int irq, void *p)
unsigned int reg_size;
unsigned int data_reg;

- reg_size = indio_dev->channels[0].scan_type.realbits +
- indio_dev->channels[0].scan_type.shift;
- reg_size = DIV_ROUND_UP(reg_size, 8);
+ reg_size = BITS_TO_BYTES(scan_type->realbits + scan_type->shift);

if (sigma_delta->info->data_reg != 0)
data_reg = sigma_delta->info->data_reg;
@@ -617,7 +618,7 @@ static irqreturn_t ad_sd_trigger_handler(int irq, void *p)
}
}

- sample_size = indio_dev->channels[0].scan_type.storagebits / 8;
+ sample_size = BITS_TO_BYTES(scan_type->storagebits);
sample_pos = sample_size * sigma_delta->current_slot;
memcpy(&sigma_delta->samples_buf[sample_pos], data, sample_size);
sigma_delta->current_slot++;

--
2.43.0