From 8f7e29e1f968751fb71210643bd32085827db4c4 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sun, 2 Sep 2018 20:17:30 -0700
Subject: [PATCH] garmin: start decoding notifications and gas change events
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The magic numbers in the decoding are all based on Wojciech Więckowski's
fit2subs python script.

The event decoding is incomplete, but it should be easy enough to add
new events as people figure them out or as the FIT SDK documentation
improves, whichever comes first.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 src/garmin_parser.c | 92 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 91 insertions(+), 1 deletion(-)

diff --git a/src/garmin_parser.c b/src/garmin_parser.c
index b004c09..7e35e32 100644
--- a/src/garmin_parser.c
+++ b/src/garmin_parser.c
@@ -66,10 +66,15 @@ struct record_data {
 	// RECORD_GASMIX
 	int index, gas_status;
 	dc_gasmix_t gasmix;
+
+	// RECORD_EVENT
+	unsigned char event_type, event_nr, event_group;
+	unsigned int event_data, event_unknown;
 };
 
 #define RECORD_GASMIX 1
 #define RECORD_DECO   2
+#define RECORD_EVENT  4
 
 typedef struct garmin_parser_t {
 	dc_parser_t base;
@@ -135,6 +140,54 @@ typedef struct garmin_parser_t {
 
 typedef int (*garmin_data_cb_t)(unsigned char type, const unsigned char *data, int len, void *user);
 
+/*
+ * Decode the event. Numbers from Wojtek's fit2subs python script
+ */
+static void garmin_event(struct garmin_parser_t *garmin,
+		unsigned char event, unsigned char type, unsigned char group,
+		unsigned int data, unsigned int unknown)
+{
+	static const struct {
+		// 1 - state, 2 - notify, 3 - warning, 4 - alarm
+		int severity;
+		const char *name;
+	} event_desc[] = {
+		[0] =  { 2, "Deco required" },
+		[3] =  { 2, "First ceiling" },
+		[4] =  { 3, "ppO2 violation" },
+		[7] =  { 2, "Time alert" },
+		[8] =  { 2, "Depth alert" },
+		[11] = { 3, "Safety stop ceiling broken" },
+		[12] = { 1, "Safety stop completed" },
+		[17] = { 2, "Ascent speed too high" },
+		[22] = { 1, "Safety stop begin" },
+	};
+	dc_sample_value_t sample = {0};
+
+	switch (event) {
+	case 38:
+		break;
+	case 48:
+		break;
+	case 56:
+		if (data >= C_ARRAY_SIZE(event_desc))
+			return;
+
+		sample.event.type = SAMPLE_EVENT_STRING;
+		sample.event.name = event_desc[data].name;
+		sample.event.flags =  event_desc[data].severity << SAMPLE_FLAGS_SEVERITY_SHIFT;
+		if (!sample.event.name)
+			return;
+		garmin->callback(DC_SAMPLE_EVENT, sample, garmin->userdata);
+		return;
+
+	case 57:
+		sample.gasmix = data - 1;
+		garmin->callback(DC_SAMPLE_GASMIX, sample, garmin->userdata);
+		return;
+	}
+}
+
 /*
  * Some data isn't just something we can save off directly: it's a record with
  * multiple fields where one field describes another.
@@ -171,6 +224,11 @@ static void flush_pending_record(struct garmin_parser_t *garmin)
 		sample.deco.depth = record->ceiling;
 		garmin->callback(DC_SAMPLE_DECO, sample, garmin->userdata);
 	}
+
+	if (pending & RECORD_EVENT) {
+		garmin_event(garmin, record->event_nr, record->event_type,
+			record->event_group, record->event_data, record->event_unknown);
+	}
 }
 
 
@@ -459,6 +517,29 @@ DECLARE_FIELD(DIVE_SUMMARY, o2_toxicity, UINT16) { }		// OTUs
 DECLARE_FIELD(DIVE_SUMMARY, dive_number, UINT32) { }
 DECLARE_FIELD(DIVE_SUMMARY, bottom_time, UINT32) { ASSIGN_FIELD(DIVETIME, data / 1000); }
 
+// EVENT
+DECLARE_FIELD(EVENT, event, ENUM)
+{
+	garmin->record_data.event_nr = data;
+	garmin->record_data.pending |= RECORD_EVENT;
+}
+DECLARE_FIELD(EVENT, type, ENUM)
+{
+	garmin->record_data.event_type = data;
+	garmin->record_data.pending |= RECORD_EVENT;
+}
+DECLARE_FIELD(EVENT, data, UINT32)
+{
+	garmin->record_data.event_data = data;
+}
+DECLARE_FIELD(EVENT, event_group, UINT8)
+{
+	garmin->record_data.event_group = data;
+}
+DECLARE_FIELD(EVENT, unknown, UINT32)
+{
+	garmin->record_data.event_unknown = data;
+}
 
 struct msg_desc {
 	unsigned char maxfield;
@@ -571,8 +652,17 @@ DECLARE_MESG(DIVE_SUMMARY) = {
 	}
 };
 
+DECLARE_MESG(EVENT) = {
+	.maxfield = 16,
+	.field = {
+		SET_FIELD(EVENT, 0, event, ENUM),
+		SET_FIELD(EVENT, 1, type, ENUM),
+		SET_FIELD(EVENT, 3, data, UINT32),
+		SET_FIELD(EVENT, 4, event_group, UINT8),
+		SET_FIELD(EVENT, 15, unknown, UINT32),
+	}
+};
 
-DECLARE_MESG(EVENT) = { };
 DECLARE_MESG(DEVICE_INFO) = { };
 DECLARE_MESG(ACTIVITY) = { };
 DECLARE_MESG(FILE_CREATOR) = { };