From 82c5f9f0f4f3af0a0709b9022f48e0e760f60c15 Mon Sep 17 00:00:00 2001
From: James Cotton <peabody124@gmail.com>
Date: Sun, 4 Sep 2011 12:37:39 -0500
Subject: [PATCH] PIOS_RCVR: Document return values better and use enum for
 them

---
 flight/PiOS/Common/pios_rcvr.c |  9 +++++++++
 flight/PiOS/inc/pios_rcvr.h    | 12 +++++++++---
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/flight/PiOS/Common/pios_rcvr.c b/flight/PiOS/Common/pios_rcvr.c
index b76e04a44..bd8cce3cd 100644
--- a/flight/PiOS/Common/pios_rcvr.c
+++ b/flight/PiOS/Common/pios_rcvr.c
@@ -76,6 +76,15 @@ out_fail:
   return(-1);
 }
 
+/**
+ * @brief Reads an input channel from the appropriate driver
+ * @param[in] rcvr_id driver to read from
+ * @param[in] channel channel to read
+ * @returns Unitless input value
+ *  @retval PIOS_RCVR_TIMEOUT indicates a failsafe or timeout from that channel
+ *  @retval PIOS_RCVR_INVALID invalid channel for this driver (usually out of range supported)
+ *  @retval PIOS_RCVR_NODRIVER driver was not initialized
+ */
 int32_t PIOS_RCVR_Read(uint32_t rcvr_id, uint8_t channel)
 {
   if (rcvr_id == 0) 
diff --git a/flight/PiOS/inc/pios_rcvr.h b/flight/PiOS/inc/pios_rcvr.h
index a61798d8c..ab493cd35 100644
--- a/flight/PiOS/inc/pios_rcvr.h
+++ b/flight/PiOS/inc/pios_rcvr.h
@@ -39,9 +39,15 @@ struct pios_rcvr_driver {
 /* Public Functions */
 extern int32_t PIOS_RCVR_Read(uint32_t rcvr_id, uint8_t channel);
 
-#define PIOS_RCVR_TIMEOUT         0
-#define PIOS_RCVR_NODRIVER        -2
-#define PIOS_RCVR_INVALID         -1
+/*! Define error codes for PIOS_RCVR_Get */
+enum PIOS_RCVR_errors {
+	/*! Indicates that a failsafe condition or missing receiver detected for that channel */
+	PIOS_RCVR_TIMEOUT = 0,
+	/*! Channel is invalid for this driver (usually out of range supported) */
+	PIOS_RCVR_INVALID = -1,
+	/*! Indicates that the driver for this channel has not been initialized */
+	PIOS_RCVR_NODRIVER = -2
+};
 
 #endif /* PIOS_RCVR_H */