iio:inkern: Add function to read the processed value
Add a function to read a processed value from a channel. The function will first
attempt to read the IIO_CHAN_INFO_PROCESSED attribute. If that fails it will
read the IIO_CHAN_INFO_RAW attribute and convert the result from a raw value to
a processed value.
The patch also introduces a function to convert raw value to a processed value
and exports it, in case a user needs or wants to do the conversion by itself.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index d539e1e..25b0076 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -238,9 +238,21 @@
}
EXPORT_SYMBOL_GPL(iio_channel_release_all);
+static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
+ enum iio_chan_info_enum info)
+{
+ int unused;
+
+ if (val2 == NULL)
+ val2 = &unused;
+
+ return chan->indio_dev->info->read_raw(chan->indio_dev, chan->channel,
+ val, val2, info);
+}
+
int iio_read_channel_raw(struct iio_channel *chan, int *val)
{
- int val2, ret;
+ int ret;
mutex_lock(&chan->indio_dev->info_exist_lock);
if (chan->indio_dev->info == NULL) {
@@ -248,10 +260,7 @@
goto err_unlock;
}
- ret = chan->indio_dev->info->read_raw(chan->indio_dev,
- chan->channel,
- val, &val2,
- IIO_CHAN_INFO_RAW);
+ ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
err_unlock:
mutex_unlock(&chan->indio_dev->info_exist_lock);
@@ -259,6 +268,100 @@
}
EXPORT_SYMBOL_GPL(iio_read_channel_raw);
+static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
+ int raw, int *processed, unsigned int scale)
+{
+ int scale_type, scale_val, scale_val2, offset;
+ s64 raw64 = raw;
+ int ret;
+
+ ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_SCALE);
+ if (ret == 0)
+ raw64 += offset;
+
+ scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
+ IIO_CHAN_INFO_SCALE);
+ if (scale_type < 0)
+ return scale_type;
+
+ switch (scale_type) {
+ case IIO_VAL_INT:
+ *processed = raw64 * scale_val;
+ break;
+ case IIO_VAL_INT_PLUS_MICRO:
+ if (scale_val2 < 0)
+ *processed = -raw64 * scale_val;
+ else
+ *processed = raw64 * scale_val;
+ *processed += div_s64(raw64 * (s64)scale_val2 * scale,
+ 1000000LL);
+ break;
+ case IIO_VAL_INT_PLUS_NANO:
+ if (scale_val2 < 0)
+ *processed = -raw64 * scale_val;
+ else
+ *processed = raw64 * scale_val;
+ *processed += div_s64(raw64 * (s64)scale_val2 * scale,
+ 1000000000LL);
+ break;
+ case IIO_VAL_FRACTIONAL:
+ *processed = div_s64(raw64 * (s64)scale_val * scale,
+ scale_val2);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
+ int *processed, unsigned int scale)
+{
+ int ret;
+
+ mutex_lock(&chan->indio_dev->info_exist_lock);
+ if (chan->indio_dev->info == NULL) {
+ ret = -ENODEV;
+ goto err_unlock;
+ }
+
+ ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed,
+ scale);
+err_unlock:
+ mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
+
+int iio_read_channel_processed(struct iio_channel *chan, int *val)
+{
+ int ret;
+
+ mutex_lock(&chan->indio_dev->info_exist_lock);
+ if (chan->indio_dev->info == NULL) {
+ ret = -ENODEV;
+ goto err_unlock;
+ }
+
+ if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
+ ret = iio_channel_read(chan, val, NULL,
+ IIO_CHAN_INFO_PROCESSED);
+ } else {
+ ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
+ if (ret < 0)
+ goto err_unlock;
+ ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1);
+ }
+
+err_unlock:
+ mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iio_read_channel_processed);
+
int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
{
int ret;
@@ -269,10 +372,7 @@
goto err_unlock;
}
- ret = chan->indio_dev->info->read_raw(chan->indio_dev,
- chan->channel,
- val, val2,
- IIO_CHAN_INFO_SCALE);
+ ret = iio_channel_read(chan, val, val2, IIO_CHAN_INFO_SCALE);
err_unlock:
mutex_unlock(&chan->indio_dev->info_exist_lock);