diff options
Diffstat (limited to 'include/linux/iio/consumer.h')
| -rw-r--r-- | include/linux/iio/consumer.h | 94 |
1 files changed, 83 insertions, 11 deletions
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h index c4118dcb8e05..6a4479616479 100644 --- a/include/linux/iio/consumer.h +++ b/include/linux/iio/consumer.h @@ -13,6 +13,7 @@ struct iio_dev; struct iio_chan_spec; struct device; +struct fwnode_handle; /** * struct iio_channel - everything needed for a consumer to use a channel @@ -97,6 +98,35 @@ void iio_channel_release_all(struct iio_channel *chan); */ struct iio_channel *devm_iio_channel_get_all(struct device *dev); +/** + * fwnode_iio_channel_get_by_name() - get description of all that is needed to access channel. + * @fwnode: Pointer to consumer Firmware node + * @consumer_channel: Unique name to identify the channel on the consumer + * side. This typically describes the channels use within + * the consumer. E.g. 'battery_voltage' + */ +struct iio_channel *fwnode_iio_channel_get_by_name(struct fwnode_handle *fwnode, + const char *name); + +/** + * devm_fwnode_iio_channel_get_by_name() - Resource managed version of + * fwnode_iio_channel_get_by_name(). + * @dev: Pointer to consumer device. + * @fwnode: Pointer to consumer Firmware node + * @consumer_channel: Unique name to identify the channel on the consumer + * side. This typically describes the channels use within + * the consumer. E.g. 'battery_voltage' + * + * Returns a pointer to negative errno if it is not able to get the iio channel + * otherwise returns valid pointer for iio channel. + * + * The allocated iio channel is automatically released when the device is + * unbound. + */ +struct iio_channel *devm_fwnode_iio_channel_get_by_name(struct device *dev, + struct fwnode_handle *fwnode, + const char *consumer_channel); + struct iio_cb_buffer; /** * iio_channel_get_all_cb() - register callback for triggered capture @@ -171,8 +201,9 @@ 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); @@ -182,8 +213,9 @@ 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. @@ -206,6 +238,21 @@ int iio_read_channel_average_raw(struct iio_channel *chan, int *val); int iio_read_channel_processed(struct iio_channel *chan, int *val); /** + * iio_read_channel_processed_scale() - read and scale a processed value + * @chan: The channel being queried. + * @val: Value read back. + * @scale: Scale factor to apply during the conversion + * + * Returns an error code or 0. + * + * This function will read a processed value from a channel. This will work + * like @iio_read_channel_processed() but also scale with an additional + * scale factor while attempting to minimize any precision loss. + */ +int iio_read_channel_processed_scale(struct iio_channel *chan, int *val, + unsigned int scale); + +/** * iio_write_channel_attribute() - Write values to the device attribute. * @chan: The channel being queried. * @val: Value being written. @@ -236,8 +283,9 @@ 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); @@ -247,12 +295,25 @@ 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. @@ -263,8 +324,9 @@ 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); @@ -356,7 +418,7 @@ 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. @@ -379,4 +441,14 @@ 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 |