sw_limits: Add documentation

Add documentation for the software limits module.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

Doxyfile

@@ -780,7 +780,7 @@ RECURSIVE              = YES
 
 EXCLUDE                = config.h src/libsigrok-internal.h src/session_driver.c
 EXCLUDE               += src/std.c src/drivers.c src/ezusb.c src/fallback.c
-EXCLUDE               += src/soft-trigger.c src/usb.c
+EXCLUDE               += src/soft-trigger.c src/usb.c src/sw_limits.c
 
 # The EXCLUDE_SYMLINKS tag can be used to select whether or not files or
 # directories that are symbolic links (a Unix file system feature) are excluded

src/sw_limits.c

@@ -17,6 +17,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+/**
+ * @file
+ * Software limits helper functions
+ * @internal
+ */
+
 #include <config.h>
 #include <stdio.h>
 #include <stdint.h>
@@ -25,12 +31,32 @@
 #include <libsigrok/libsigrok.h>
 #include "libsigrok-internal.h"
 
+/**
+ * Initialize a software limit instance
+ *
+ * Must be called before any other operations are performed on a struct
+ * sr_sw_limits and should typically be called after the data structure has been
+ * allocated.
+ *
+ * @param limits the software limit instance to initialize
+ */
 SR_PRIV void sr_sw_limits_init(struct sr_sw_limits *limits)
 {
 	limits->limit_samples = 0;
 	limits->limit_msec = 0;
 }
 
+/**
+ * Get software limit configuration
+ *
+ * Retrieve the currently configured software limit for the specified key.
+ * Should be called from the drivers config_get() callback.
+ *
+ * @param limits software limit instance
+ * @param key config item key
+ * @param data config item data
+ * @return SR_ERR_NA if @p key is not a supported limit, SR_OK otherwise
+ */
 SR_PRIV int sr_sw_limits_config_get(struct sr_sw_limits *limits, uint32_t key,
 	GVariant **data)
 {
@@ -48,6 +74,17 @@ SR_PRIV int sr_sw_limits_config_get(struct sr_sw_limits *limits, uint32_t key,
 	return SR_OK;
 }
 
+/**
+ * Set software limit configuration
+ *
+ * Configure software limit for the specified key. Should be called from the
+ * drivers config_set() callback.
+ *
+ * @param limits software limit instance
+ * @param key config item key
+ * @param data config item data
+ * @return SR_ERR_NA if @p key is not a supported limit, SR_OK otherwise
+ */
 SR_PRIV int sr_sw_limits_config_set(struct sr_sw_limits *limits, uint32_t key,
 	GVariant *data)
 {
@@ -65,12 +102,30 @@ SR_PRIV int sr_sw_limits_config_set(struct sr_sw_limits *limits, uint32_t key,
 	return SR_OK;
 }
 
+/**
+ * Start a new data acquisition session
+ *
+ * Resets the internal accounting for all software limits. Usually should be
+ * called from the drivers acquisition_start() callback.
+ *
+ * @param limits software limits instance
+ */
 SR_PRIV void sr_sw_limits_acquisition_start(struct sr_sw_limits *limits)
 {
 	limits->samples_read = 0;
 	limits->start_time = g_get_monotonic_time();
 }
 
+/**
+ * Check if any of the configured software limits has been reached
+ *
+ * Usually should be called at the end of the drivers work function after all
+ * processing has been done.
+ *
+ * @param limits software limits instance
+ * @returns TRUE if any of the software limits has been reached and the driver
+ *   should stop data acquisition, otherwise FALSE.
+ */
 SR_PRIV gboolean sr_sw_limits_check(struct sr_sw_limits *limits)
 {
 	if (limits->limit_samples) {
@@ -89,6 +144,17 @@ SR_PRIV gboolean sr_sw_limits_check(struct sr_sw_limits *limits)
 	return FALSE;
 }
 
+/**
+ * Update the amount samples that have been read
+ *
+ * Update the amount of samples that have been read in the current data
+ * acquisition run. For each invocation @p samples_read will be accumulated and
+ * once the configured sample limit has been reached sr_sw_limits_check() will
+ * return TRUE.
+ *
+ * @param limits software limits instance
+ * @param samples_read the amount of samples that have been read
+ */
 SR_PRIV void sr_sw_limits_update_samples_read(struct sr_sw_limits *limits,
 	uint64_t samples_read)
 {