xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

iio:inkern: Add function to read the processed value

Browse Source 
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>
This commit is contained in:
Lars-Peter Clausen
2012-09-17 13:17:00 +01:00
committed by Jonathan Cameron
parent 45f010baa0
commit 48e44ce0f8
3 changed files with 164 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
include/linux/iio/consumer.h
View File

@@ -70,6 +70,21 @@ void iio_channel_release_all(struct iio_channel *chan);
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.
@@ -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

17
include/linux/iio/iio.h
View File

@@ -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 }