diff options
Diffstat (limited to 'include/linux/iio/consumer.h')
| -rw-r--r-- | include/linux/iio/consumer.h | 70 |
1 files changed, 58 insertions, 12 deletions
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h index 6802596b017c..5039558267e4 100644 --- a/include/linux/iio/consumer.h +++ b/include/linux/iio/consumer.h @@ -131,7 +131,8 @@ struct iio_cb_buffer; /** * iio_channel_get_all_cb() - register callback for triggered capture * @dev: Pointer to client device. - * @cb: Callback function. + * @cb: Callback function. Must be safe to call from any context + * (e.g. must not sleep). * @private: Private data passed to callback. * * NB right now we have no ability to mux data from multiple devices. @@ -201,8 +202,9 @@ struct iio_dev * @chan: The channel being queried. * @val: Value read back. * - * Note raw reads from iio channels are in adc counts and hence - * scale will need to be applied if standard units required. + * Note, if standard units are required, raw reads from iio channels + * need the offset (default 0) and scale (default 1) to be applied + * as (raw + offset) * scale. */ int iio_read_channel_raw(struct iio_channel *chan, int *val); @@ -212,8 +214,9 @@ int iio_read_channel_raw(struct iio_channel *chan, * @chan: The channel being queried. * @val: Value read back. * - * Note raw reads from iio channels are in adc counts and hence - * scale will need to be applied if standard units required. + * Note, if standard units are required, raw reads from iio channels + * need the offset (default 0) and scale (default 1) to be applied + * as (raw + offset) * scale. * * In opposit to the normal iio_read_channel_raw this function * returns the average of multiple reads. @@ -281,8 +284,9 @@ int iio_read_channel_attribute(struct iio_channel *chan, int *val, * @chan: The channel being queried. * @val: Value being written. * - * Note raw writes to iio channels are in dac counts and hence - * scale will need to be applied if standard units required. + * Note that for raw writes to iio channels, if the value provided is + * in standard units, the affect of the scale and offset must be removed + * as (value / scale) - offset. */ int iio_write_channel_raw(struct iio_channel *chan, int val); @@ -292,12 +296,25 @@ int iio_write_channel_raw(struct iio_channel *chan, int val); * @chan: The channel being queried. * @val: Value read back. * - * Note raw reads from iio channels are in adc counts and hence - * scale will need to be applied if standard units are required. + * Note, if standard units are required, raw reads from iio channels + * need the offset (default 0) and scale (default 1) to be applied + * as (raw + offset) * scale. */ int iio_read_max_channel_raw(struct iio_channel *chan, int *val); /** + * iio_read_min_channel_raw() - read minimum available raw value from a given + * channel, i.e. the minimum possible value. + * @chan: The channel being queried. + * @val: Value read back. + * + * Note, if standard units are required, raw reads from iio channels + * need the offset (default 0) and scale (default 1) to be applied + * as (raw + offset) * scale. + */ +int iio_read_min_channel_raw(struct iio_channel *chan, int *val); + +/** * iio_read_avail_channel_raw() - read available raw values from a given channel * @chan: The channel being queried. * @vals: Available values read back. @@ -308,8 +325,9 @@ int iio_read_max_channel_raw(struct iio_channel *chan, int *val); * For ranges, three vals are always returned; min, step and max. * For lists, all the possible values are enumerated. * - * Note raw available values from iio channels are in adc counts and - * hence scale will need to be applied if standard units are required. + * Note, if standard units are required, raw available values from iio + * channels need the offset (default 0) and scale (default 1) to be applied + * as (raw + offset) * scale. */ int iio_read_avail_channel_raw(struct iio_channel *chan, const int **vals, int *length); @@ -365,6 +383,24 @@ int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2); /** + * iio_multiply_value() - Multiply an IIO value + * @result: Destination pointer for the multiplication result + * @multiplier: Multiplier. + * @type: One of the IIO_VAL_* constants. This decides how the @val and + * @val2 parameters are interpreted. + * @val: Value being multiplied. + * @val2: Value being multiplied. @val2 use depends on type. + * + * Multiply an IIO value with a s64 multiplier storing the result as + * IIO_VAL_INT. This is typically used for scaling. + * + * Returns: + * IIO_VAL_INT on success or a negative error-number on failure. + */ +int iio_multiply_value(int *result, s64 multiplier, + unsigned int type, 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 @@ -401,7 +437,7 @@ unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan); * @chan: The channel being queried. * @attr: The ext_info attribute to read. * @buf: Where to store the attribute value. Assumed to hold - * at least PAGE_SIZE bytes. + * at least PAGE_SIZE bytes and to be aligned at PAGE_SIZE. * * Returns the number of bytes written to buf (perhaps w/o zero termination; * it need not even be a string), or an error code. @@ -424,4 +460,14 @@ ssize_t iio_read_channel_ext_info(struct iio_channel *chan, ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr, const char *buf, size_t len); +/** + * iio_read_channel_label() - read label for a given channel + * @chan: The channel being queried. + * @buf: Where to store the attribute value. Assumed to hold + * at least PAGE_SIZE bytes and to be aligned at PAGE_SIZE. + * + * Returns the number of bytes written to buf, or an error code. + */ +ssize_t iio_read_channel_label(struct iio_channel *chan, char *buf); + #endif |