diff options
| -rw-r--r-- | drivers/iio/inkern.c | 118 | ||||
| -rw-r--r-- | include/linux/iio/consumer.h | 38 | ||||
| -rw-r--r-- | include/linux/iio/iio.h | 17 |
3 files changed, 164 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); diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h index 62118dd707d7..e875bcf0478f 100644 --- a/include/linux/iio/consumer.h +++ b/include/linux/iio/consumer.h @@ -71,6 +71,21 @@ int iio_read_channel_raw(struct iio_channel *chan, int *val); /** + * iio_read_channel_processed() - read processed value from a given channel + * @chan: The channel being queried. + * @val: Value read back. + * + * Returns an error code or 0. + * + * This function will read a processed value from a channel. A processed value + * means that this value will have the correct unit and not some device internal + * representation. If the device does not support reporting a processed value + * the function will query the raw value and the channels scale and offset and + * do the appropriate transformation. + */ +int iio_read_channel_processed(struct iio_channel *chan, int *val); + +/** * iio_get_channel_type() - get the type of a channel * @channel: The channel being queried. * @type: The type of the channel. @@ -93,4 +108,27 @@ int iio_get_channel_type(struct iio_channel *channel, int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2); +/** + * iio_convert_raw_to_processed() - Converts a raw value to a processed value + * @chan: The channel being queried + * @raw: The raw IIO to convert + * @processed: The result of the conversion + * @scale: Scale factor to apply during the conversion + * + * Returns an error code or 0. + * + * This function converts a raw value to processed value for a specific channel. + * A raw value is the device internal representation of a sample and the value + * returned by iio_read_channel_raw, so the unit of that value is device + * depended. A processed value on the other hand is value has a normed unit + * according with the IIO specification. + * + * The scale factor allows to increase the precession of the returned value. For + * a scale factor of 1 the function will return the result in the normal IIO + * unit for the channel type. E.g. millivolt for voltage channels, if you want + * nanovolts instead pass 1000 as the scale factor. + */ +int iio_convert_raw_to_processed(struct iio_channel *chan, int raw, + int *processed, unsigned int scale); + #endif diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 30affa533a1f..c0ae76ac4e0b 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -40,6 +40,8 @@ enum iio_chan_info_enum { #define IIO_CHAN_INFO_SHARED_BIT(type) BIT(type*2) #define IIO_CHAN_INFO_SEPARATE_BIT(type) BIT(type*2 + 1) +#define IIO_CHAN_INFO_BITS(type) (IIO_CHAN_INFO_SHARED_BIT(type) | \ + IIO_CHAN_INFO_SEPARATE_BIT(type)) #define IIO_CHAN_INFO_RAW_SEPARATE_BIT \ IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_RAW) @@ -261,6 +263,21 @@ struct iio_chan_spec { unsigned differential:1; }; + +/** + * iio_channel_has_info() - Checks whether a channel supports a info attribute + * @chan: The channel to be queried + * @type: Type of the info attribute to be checked + * + * Returns true if the channels supports reporting values for the given info + * attribute type, false otherwise. + */ +static inline bool iio_channel_has_info(const struct iio_chan_spec *chan, + enum iio_chan_info_enum type) +{ + return chan->info_mask & IIO_CHAN_INFO_BITS(type); +} + #define IIO_ST(si, rb, sb, sh) \ { .sign = si, .realbits = rb, .storagebits = sb, .shift = sh } |