tools:iio:iio_utils: add missing documentation

Fully document public functions and elements.
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

tools/iio/iio_utils.c

@@ -29,6 +29,8 @@ static char * const iio_direction[] = {
  * iioutils_break_up_name() - extract generic name from full channel name
  * @full_name: the full channel name
  * @generic_name: the output generic channel name
+ *
+ * Returns 0 on success, or a negative error code if string extraction failed.
  **/
 int iioutils_break_up_name(const char *full_name,
 				  char **generic_name)
@@ -76,11 +78,15 @@ int iioutils_break_up_name(const char *full_name,
  * iioutils_get_type() - find and process _type attribute data
  * @is_signed: output whether channel is signed
  * @bytes: output how many bytes the channel storage occupies
+ * @bits_used: output number of valid bits of data
+ * @shift: output amount of bits to shift right data before applying bit mask
  * @mask: output a bit mask for the raw data
- * @be: big endian
- * @device_dir: the iio device directory
+ * @be: output if data in big endian
+ * @device_dir: the IIO device directory
  * @name: the channel name
  * @generic_name: the channel type name
+ *
+ * Returns a value >= 0 on success, otherwise a negative error code.
  **/
 int iioutils_get_type(unsigned *is_signed,
 			     unsigned *bytes,
@@ -200,6 +206,16 @@ int iioutils_get_type(unsigned *is_signed,
 	return ret;
 }
 
+/**
+ * iioutils_get_param_float() - read a float value from a channel parameter
+ * @output: output the float value
+ * @param_name: the parameter name to read
+ * @device_dir: the IIO device directory in sysfs
+ * @name: the channel name
+ * @generic_name: the channel type name
+ *
+ * Returns a value >= 0 on success, otherwise a negative error code.
+ **/
 int iioutils_get_param_float(float *output,
 				    const char *param_name,
 				    const char *device_dir,
@@ -266,8 +282,9 @@ int iioutils_get_param_float(float *output,
 }
 
 /**
- * bsort_channel_array_by_index() - reorder so that the array is in index order
- *
+ * bsort_channel_array_by_index() - sort the array in index order
+ * @ci_array: the iio_channel_info array to be sorted
+ * @cnt: the amount of array elements
  **/
 
 void bsort_channel_array_by_index(struct iio_channel_info **ci_array,
@@ -289,7 +306,10 @@ void bsort_channel_array_by_index(struct iio_channel_info **ci_array,
 /**
  * build_channel_array() - function to figure out what channels are present
  * @device_dir: the IIO device directory in sysfs
- * @
+ * @ci_array: output the resulting array of iio_channel_info
+ * @counter: output the amount of array elements
+ *
+ * Returns 0 on success, otherwise a negative error code.
  **/
 int build_channel_array(const char *device_dir,
 			      struct iio_channel_info **ci_array,
@@ -525,8 +545,10 @@ int calc_digits(int num)
 /**
  * find_type_by_name() - function to match top level types by name
  * @name: top level type instance name
- * @type: the type of top level instance being sort
+ * @type: the type of top level instance being searched
  *
+ * Returns the device number of a matched IIO device on success, otherwise a
+ * negative error code.
  * Typical types this is used for are device and trigger.
  **/
 int find_type_by_name(const char *name, const char *type)
@@ -684,11 +706,28 @@ static int _write_sysfs_int(char *filename, char *basedir, int val, int verify)
 	return ret;
 }
 
+/**
+ * write_sysfs_int() - write an integer value to a sysfs file
+ * @filename: name of the file to write to
+ * @basedir: the sysfs directory in which the file is to be found
+ * @val: integer value to write to file
+ *
+ * Returns a value >= 0 on success, otherwise a negative error code.
+ **/
 int write_sysfs_int(char *filename, char *basedir, int val)
 {
 	return _write_sysfs_int(filename, basedir, val, 0);
 }
 
+/**
+ * write_sysfs_int_and_verify() - write an integer value to a sysfs file
+ *				  and verify
+ * @filename: name of the file to write to
+ * @basedir: the sysfs directory in which the file is to be found
+ * @val: integer value to write to file
+ *
+ * Returns a value >= 0 on success, otherwise a negative error code.
+ **/
 int write_sysfs_int_and_verify(char *filename, char *basedir, int val)
 {
 	return _write_sysfs_int(filename, basedir, val, 1);
@@ -770,17 +809,35 @@ static int _write_sysfs_string(char *filename, char *basedir, char *val,
  * @filename: name of file to write to
  * @basedir: the sysfs directory in which the file is to be found
  * @val: the string to write
+ *
+ * Returns a value >= 0 on success, otherwise a negative error code.
  **/
 int write_sysfs_string_and_verify(char *filename, char *basedir, char *val)
 {
 	return _write_sysfs_string(filename, basedir, val, 1);
 }
 
+/**
+ * write_sysfs_string() - write string to a sysfs file
+ * @filename: name of file to write to
+ * @basedir: the sysfs directory in which the file is to be found
+ * @val: the string to write
+ *
+ * Returns a value >= 0 on success, otherwise a negative error code.
+ **/
 int write_sysfs_string(char *filename, char *basedir, char *val)
 {
 	return _write_sysfs_string(filename, basedir, val, 0);
 }
 
+/**
+ * read_sysfs_posint() - read an integer value from file
+ * @filename: name of file to read from
+ * @basedir: the sysfs directory in which the file is to be found
+ *
+ * Returns the read integer value >= 0 on success, otherwise a negative error
+ * code.
+ **/
 int read_sysfs_posint(char *filename, char *basedir)
 {
 	int ret;
@@ -817,6 +874,14 @@ int read_sysfs_posint(char *filename, char *basedir)
 	return ret;
 }
 
+/**
+ * read_sysfs_float() - read a float value from file
+ * @filename: name of file to read from
+ * @basedir: the sysfs directory in which the file is to be found
+ * @val: output the read float value
+ *
+ * Returns a value >= 0 on success, otherwise a negative error code.
+ **/
 int read_sysfs_float(char *filename, char *basedir, float *val)
 {
 	int ret = 0;
@@ -853,6 +918,14 @@ int read_sysfs_float(char *filename, char *basedir, float *val)
 	return ret;
 }
 
+/**
+ * read_sysfs_string() - read a string from file
+ * @filename: name of file to read from
+ * @basedir: the sysfs directory in which the file is to be found
+ * @str: output the read string
+ *
+ * Returns a value >= 0 on success, otherwise a negative error code.
+ **/
 int read_sysfs_string(const char *filename, const char *basedir, char *str)
 {
 	int ret = 0;

tools/iio/iio_utils.h

@@ -28,9 +28,12 @@ extern const char *iio_dir;
  * @offset: offset to be applied for conversion to si units
  * @index: the channel index in the buffer output
  * @bytes: number of bytes occupied in buffer output
+ * @bits_used: number of valid bits of data
+ * @shift: amount of bits to shift right data before applying bit mask
  * @mask: a bit mask for the raw output
+ * @be: flag if data is big endian
  * @is_signed: is the raw value stored signed
- * @enabled: is this channel enabled
+ * @location: data offset for this channel inside the buffer (in bytes)
  **/
 struct iio_channel_info {
 	char *name;