[RFC v2 16/16] HoG: Prepend report id to the HID report

["João Paulo Rechi Vita" <jprvita@openbossa.org>]

If the report descriptor has a report id tag it have to be prepended
to the report data to construct the report itself.
---
 input/hog_device.c |   74 ++++++++++++++++++++++++++++++++++++++++++----------
 1 files changed, 60 insertions(+), 14 deletions(-)

diff --git a/input/hog_device.c b/input/hog_device.c
index cfe8f03..b7eea96 100644
--- a/input/hog_device.c
+++ b/input/hog_device.c
@@ -59,10 +59,6 @@
 #define MIN(x, y) ((x) < (y) ? (x) : (y))
 #endif
 
-struct report {
-	struct gatt_char *decl;
-};
-
 struct hog_device {
 	char			*path;
 	struct btd_device	*device;
@@ -72,6 +68,14 @@ struct hog_device {
 	struct gatt_primary	*hog_primary;
 	GSList			*reports;
 	int			uhid_fd;
+	gboolean		prepend_id;
+};
+
+struct report {
+	uint8_t			id;
+	uint8_t			type;
+	struct gatt_char	*decl;
+	struct hog_device	*hogdev;
 };
 
 static GSList *devices = NULL;
@@ -82,12 +86,23 @@ static void report_free(struct report *report)
 	g_free(report);
 }
 
+static gint report_handle_cmp(gconstpointer a, gconstpointer b)
+{
+	const struct report *report = a;
+	uint16_t handle = GPOINTER_TO_UINT(b);
+
+	return report->decl->value_handle - handle;
+}
+
 static void report_value_cb(const uint8_t *pdu, uint16_t len, gpointer user_data)
 {
 	struct hog_device *hogdev = user_data;
 	struct uhid_event ev;
 	uint16_t handle;
 	uint16_t report_size = len - 3;
+	GSList *l;
+	struct report *report;
+	uint8_t *buf;
 
 	if (len < 3) {
 		error("Malformed ATT notification");
@@ -100,10 +115,26 @@ static void report_value_cb(const uint8_t *pdu, uint16_t len, gpointer user_data
 				"0x%02x", handle, pdu[2], pdu[3], pdu[4],
 				pdu[5], pdu[6], pdu[7], pdu[8], pdu[9]);
 
+	l = g_slist_find_custom(hogdev->reports, GUINT_TO_POINTER(handle),
+							report_handle_cmp);
+	if (!l) {
+		error("Invalid report");
+		return;
+	}
+	report = l->data;
+
 	memset(&ev, 0, sizeof(ev));
 	ev.type = UHID_INPUT;
 	ev.u.input.size = MIN(report_size, UHID_DATA_MAX);
-	memcpy(ev.u.input.data, &pdu[3], MIN(report_size, UHID_DATA_MAX));
+
+	buf = ev.u.input.data;
+	if (hogdev->prepend_id) {
+		*buf = report->id;
+		buf++;
+		ev.u.input.size++;
+	}
+
+	memcpy(buf, &pdu[3], MIN(report_size, UHID_DATA_MAX));
 
 	if (write(hogdev->uhid_fd, &ev, sizeof(ev)) < 0)
 		error("UHID write failed: %s", strerror(errno));
@@ -133,6 +164,8 @@ static void write_ccc(uint16_t handle, gpointer user_data)
 static void report_reference_cb(guint8 status, const guint8 *pdu,
 					guint16 plen, gpointer user_data)
 {
+	struct report *report = user_data;
+
 	if (status != 0) {
 		error("Read Report Reference descriptor failed: %s",
 							att_ecode2str(status));
@@ -144,13 +177,16 @@ static void report_reference_cb(guint8 status, const guint8 *pdu,
 		return;
 	}
 
+	report->id = pdu[1];
+	report->type = pdu[2];
 	DBG("Report ID: 0x%02x Report type: 0x%02x", pdu[1], pdu[2]);
 }
 
 static void discover_descriptor_cb(guint8 status, const guint8 *pdu,
 					guint16 len, gpointer user_data)
 {
-	struct hog_device *hogdev = user_data;
+	struct report *report = user_data;
+	struct hog_device *hogdev = report->hogdev;
 	struct att_data_list *list;
 	uint8_t format;
 	int i;
@@ -177,10 +213,10 @@ static void discover_descriptor_cb(guint8 status, const guint8 *pdu,
 		uuid16 = att_get_u16(&value[2]);
 
 		if (uuid16 == GATT_CLIENT_CHARAC_CFG_UUID)
-			write_ccc(handle, user_data);
+			write_ccc(handle, hogdev);
 		else if (uuid16 == GATT_REPORT_REFERENCE)
 			gatt_read_char(hogdev->attrib, handle, 0,
-					report_reference_cb, hogdev);
+					report_reference_cb, report);
 	}
 
 done:
@@ -221,11 +257,20 @@ static void report_map_read_cb(guint8 status, const guint8 *pdu, guint16 plen,
 	}
 
 	DBG("Report MAP:");
-	for (i = 0; i < vlen; i += 2) {
-		if (i + 1 == vlen)
-			DBG("\t %02x", value[i]);
-		else
-			DBG("\t %02x %02x", value[i], value[i + 1]);
+	for (i = 0; i < vlen; i++) {
+		switch (value[i]) {
+			case 0x85:
+			case 0x86:
+			case 0x87:
+				hogdev->prepend_id = TRUE;
+		}
+
+		if (i % 2 == 0) {
+			if (i + 1 == vlen)
+				DBG("\t %02x", value[i]);
+			else
+				DBG("\t %02x %02x", value[i], value[i + 1]);
+		}
 	}
 
 	vendor_src = btd_device_get_vendor_src(hogdev->device);
@@ -281,10 +326,11 @@ static void char_discovered_cb(GSList *chars, guint8 status, gpointer user_data)
 
 		if (bt_uuid_cmp(&uuid, &report_uuid) == 0) {
 			report = g_new0(struct report, 1);
+			report->hogdev = hogdev;
 			report->decl = g_memdup(chr, sizeof(*chr));
 			hogdev->reports = g_slist_append(hogdev->reports,
 								report);
-			discover_descriptor(hogdev->attrib, chr, next, hogdev);
+			discover_descriptor(hogdev->attrib, chr, next, report);
 		} else if (bt_uuid_cmp(&uuid, &report_map_uuid) == 0)
 			gatt_read_char(hogdev->attrib, chr->value_handle, 0,
 						report_map_read_cb, hogdev);
-- 
1.7.7.6