diff --git a/drivers/qmimodem/voice.h b/drivers/qmimodem/voice.h
new file mode 100644
index 00000000..ca146491
--- /dev/null
+++ b/drivers/qmimodem/voice.h
@@ -0,0 +1,62 @@
+/*
+ *
+ *  oFono - Open Source Telephony
+ *
+ *  Copyright (C) 2017 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ */
+
+#define QMI_VOICE_PARAM_USS_DATA 0x01
+
+#define QMI_VOICE_PARAM_ASYNC_USSD_ERROR 0x10
+#define QMI_VOICE_PARAM_ASYNC_USSD_FAILURE_CASE 0x11
+#define QMI_VOICE_PARAM_ASYNC_USSD_DATA 0x12
+
+#define QMI_VOICE_PARAM_USSD_IND_USER_ACTION 0x01
+#define QMI_VOICE_PARAM_USSD_IND_DATA 0x10
+#define QMI_VOICE_PARAM_USSD_IND_UCS2 0x11
+
+/* according to GSM TS 23.038 section 5
+ * coding group 1111, No message class, 8 bit data
+ */
+#define USSD_DCS_8BIT 0xf4
+/* coding group 01xx, Class 0, UCS2 (16 bit) */
+#define USSD_DCS_UCS2 0x48
+/* default alphabet Language unspecific */
+#define USSD_DCS_UNSPECIFIC 0x0f
+
+/* based on qmi ussd definition */
+enum qmi_ussd_dcs {
+	QMI_USSD_DCS_ASCII = 0x1,
+	QMI_USSD_DCS_8BIT,
+	QMI_USSD_DCS_UCS2,
+};
+
+enum qmi_ussd_user_required {
+	QMI_USSD_NO_USER_ACTION_REQUIRED = 0x1,
+	QMI_USSD_USER_ACTION_REQUIRED,
+};
+
+/* QMI service voice. Using an enum to prevent doublicated entries */
+enum voice_commands {
+	QMI_VOICE_CANCEL_USSD =		0x3c,
+	QMI_VOICE_USSD_RELEASE_IND =	0x3d,
+	QMI_VOICE_USSD_IND =		0x3e,
+	QMI_VOICE_SUPS_IND =		0x42,
+	QMI_VOICE_ASYNC_ORIG_USSD =	0x43,
+};
+
+struct qmi_ussd_data {
+	uint8_t dcs;
+	uint8_t length;
+	uint8_t data[0];
+} __attribute__((__packed__));