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author | Lars-Peter Clausen <lars@metafoo.de> | 2012-09-17 13:17:00 +0100 |
---|---|---|
committer | Jonathan Cameron <jic23@kernel.org> | 2012-09-17 21:48:51 +0100 |
commit | 48e44ce0f8810b530fc83a4f5eb67149280d9b82 (patch) | |
tree | ce32b7a0917edb95fe5b4c3de1edd33e8d0f7ed6 /drivers/iio | |
parent | 45f010baa0292c367168b1f62d5494965b905b5d (diff) | |
download | linux-stable-48e44ce0f8810b530fc83a4f5eb67149280d9b82.tar.gz linux-stable-48e44ce0f8810b530fc83a4f5eb67149280d9b82.tar.bz2 linux-stable-48e44ce0f8810b530fc83a4f5eb67149280d9b82.zip |
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>
Diffstat (limited to 'drivers/iio')
-rw-r--r-- | drivers/iio/inkern.c | 118 |
1 files changed, 109 insertions, 9 deletions
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index d539e1e297ba..25b00761005a 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -238,9 +238,21 @@ void iio_channel_release_all(struct iio_channel *channels) } 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 @@ int iio_read_channel_raw(struct iio_channel *chan, int *val) 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 @@ err_unlock: } 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 @@ int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2) 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); |