diff --git a/drivers/atmodem/atmodem.c b/drivers/atmodem/atmodem.c
index df32517c..01cbbab2 100644
--- a/drivers/atmodem/atmodem.c
+++ b/drivers/atmodem/atmodem.c
@@ -203,7 +203,7 @@ static void at_query_manufacturer(struct ofono_modem *modem,
 				ofono_modem_attribute_query_cb_t cb, void *data)
 {
 	struct attr_cb_info *info = attr_cb_info_new(cb, data, "+CGMI:");
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (!info)
 		goto error;
@@ -226,7 +226,7 @@ static void at_query_model(struct ofono_modem *modem,
 				ofono_modem_attribute_query_cb_t cb, void *data)
 {
 	struct attr_cb_info *info = attr_cb_info_new(cb, data, "+CGMM:");
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (!info)
 		goto error;
@@ -249,7 +249,7 @@ static void at_query_revision(struct ofono_modem *modem,
 				ofono_modem_attribute_query_cb_t cb, void *data)
 {
 	struct attr_cb_info *info = attr_cb_info_new(cb, data, "+CGMR:");
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (!info)
 		goto error;
@@ -272,7 +272,7 @@ static void at_query_serial(struct ofono_modem *modem,
 				ofono_modem_attribute_query_cb_t cb, void *data)
 {
 	struct attr_cb_info *info = attr_cb_info_new(cb, data, "+CGSN:");
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (!info)
 		goto error;
diff --git a/drivers/atmodem/call-barring.c b/drivers/atmodem/call-barring.c
index f0ba18e9..3af2f8a8 100644
--- a/drivers/atmodem/call-barring.c
+++ b/drivers/atmodem/call-barring.c
@@ -31,6 +31,7 @@
 #include <glib.h>
 
 #include <ofono/log.h>
+#include <ofono/modem.h>
 #include "driver.h"
 
 #include "gatchat.h"
@@ -81,7 +82,7 @@ static void at_call_barring_query(struct ofono_modem *modem, const char *lock,
 					int cls, ofono_call_barring_cb_t cb,
 					void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 	int len;
@@ -120,7 +121,7 @@ static void at_call_barring_set(struct ofono_modem *modem, const char *lock,
 				int enable, const char *passwd, int cls,
 				ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 	int len;
@@ -168,7 +169,7 @@ static void at_call_barring_set_passwd(struct ofono_modem *modem,
 				const char *old_passwd, const char *new_passwd,
 				ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
diff --git a/drivers/atmodem/call-forwarding.c b/drivers/atmodem/call-forwarding.c
index b152b110..0e1e2883 100644
--- a/drivers/atmodem/call-forwarding.c
+++ b/drivers/atmodem/call-forwarding.c
@@ -31,6 +31,7 @@
 #include <glib.h>
 
 #include <ofono/log.h>
+#include <ofono/modem.h>
 #include "driver.h"
 
 #include "gatchat.h"
@@ -124,7 +125,7 @@ out:
 static void at_ccfc_query(struct ofono_modem *modem, int type, int cls,
 				ofono_call_forwarding_query_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
@@ -167,7 +168,7 @@ static void ccfc_set_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_ccfc_set(struct ofono_modem *modem, const char *buf,
 				ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
diff --git a/drivers/atmodem/call-meter.c b/drivers/atmodem/call-meter.c
index e7c55c3a..e5649005 100644
--- a/drivers/atmodem/call-meter.c
+++ b/drivers/atmodem/call-meter.c
@@ -31,6 +31,7 @@
 #include <glib.h>
 
 #include <ofono/log.h>
+#include <ofono/modem.h>
 #include "driver.h"
 
 #include "gatchat.h"
@@ -112,7 +113,7 @@ static void cccm_notify(GAtResult *result, gpointer user_data)
 static void at_caoc_query(struct ofono_modem *modem, ofono_call_meter_query_cb_t cb,
 				void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -136,7 +137,7 @@ error:
 static void at_cacm_query(struct ofono_modem *modem, ofono_call_meter_query_cb_t cb,
 				void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -172,7 +173,7 @@ static void generic_set_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_cacm_set(struct ofono_modem *modem, const char *passwd,
 			ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
@@ -198,7 +199,7 @@ error:
 static void at_camm_query(struct ofono_modem *modem, ofono_call_meter_query_cb_t cb,
 				void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -222,7 +223,7 @@ error:
 static void at_camm_set(struct ofono_modem *modem,	int accmax, const char *passwd,
 			ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
@@ -285,7 +286,7 @@ static void cpuc_query_cb(gboolean ok,
 static void at_cpuc_query(struct ofono_modem *modem,
 				ofono_call_meter_puct_query_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -310,7 +311,7 @@ static void at_cpuc_set(struct ofono_modem *modem, const char *currency,
 			double ppu, const char *passwd, ofono_generic_cb_t cb,
 			void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
@@ -362,7 +363,7 @@ static void at_call_meter_initialized(gboolean ok, GAtResult *result,
 					gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	g_at_chat_register(at->parser, "+CCCM:",
 			cccm_notify, FALSE, modem, NULL);
@@ -374,7 +375,7 @@ static void at_call_meter_initialized(gboolean ok, GAtResult *result,
 
 void at_call_meter_init(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	g_at_chat_send(at->parser, "AT+CAOC=2", NULL, NULL, NULL, NULL);
 	g_at_chat_send(at->parser, "AT+CCWE=1", NULL,
diff --git a/drivers/atmodem/call-settings.c b/drivers/atmodem/call-settings.c
index 30420cec..668bf65b 100644
--- a/drivers/atmodem/call-settings.c
+++ b/drivers/atmodem/call-settings.c
@@ -31,6 +31,7 @@
 #include <glib.h>
 
 #include <ofono/log.h>
+#include <ofono/modem.h>
 #include "driver.h"
 
 #include "gatchat.h"
@@ -79,7 +80,7 @@ out:
 static void at_ccwa_query(struct ofono_modem *modem, int cls,
 				ofono_call_waiting_status_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
@@ -122,7 +123,7 @@ static void ccwa_set_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_ccwa_set(struct ofono_modem *modem, int mode, int cls,
 				ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
@@ -183,7 +184,7 @@ static void clip_query_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_clip_query(struct ofono_modem *modem,
 				ofono_call_setting_status_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -240,7 +241,7 @@ static void colp_query_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_colp_query(struct ofono_modem *modem,
 				ofono_call_setting_status_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -297,7 +298,7 @@ static void clir_query_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_clir_query(struct ofono_modem *modem,
 				ofono_clir_setting_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -332,7 +333,7 @@ static void clir_set_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_clir_set(struct ofono_modem *modem, int mode,
 				ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
diff --git a/drivers/atmodem/network-registration.c b/drivers/atmodem/network-registration.c
index a9a67c46..d283b2d0 100644
--- a/drivers/atmodem/network-registration.c
+++ b/drivers/atmodem/network-registration.c
@@ -31,6 +31,7 @@
 #include <glib.h>
 
 #include <ofono/log.h>
+#include <ofono/modem.h>
 #include "driver.h"
 
 #include "gatchat.h"
@@ -113,7 +114,7 @@ static void at_registration_status(struct ofono_modem *modem,
 					ofono_registration_status_cb_t cb,
 					void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -136,7 +137,7 @@ error:
 static void cops_cb(gboolean ok, GAtResult *result, gpointer user_data)
 {
 	struct cb_data *cbd = user_data;
-	struct at_data *at = ofono_modem_userdata(cbd->modem);
+	struct at_data *at = ofono_modem_get_userdata(cbd->modem);
 	ofono_current_operator_cb_t cb = cbd->cb;
 	struct ofono_network_operator op;
 	GAtResultIter iter;
@@ -206,7 +207,7 @@ error:
 static void cops_numeric_cb(gboolean ok, GAtResult *result, gpointer user_data)
 {
 	struct cb_data *cbd = user_data;
-	struct at_data *at = ofono_modem_userdata(cbd->modem);
+	struct at_data *at = ofono_modem_get_userdata(cbd->modem);
 	GAtResultIter iter;
 	const char *str;
 	int format;
@@ -247,7 +248,7 @@ error:
 static void at_current_operator(struct ofono_modem *modem,
 				ofono_current_operator_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	gboolean ok;
 
@@ -388,7 +389,7 @@ static void cops_list_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_list_operators(struct ofono_modem *modem, ofono_operator_list_cb_t cb,
 				void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -423,7 +424,7 @@ static void register_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_register_auto(struct ofono_modem *modem, ofono_generic_cb_t cb,
 				void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -447,7 +448,7 @@ static void at_register_manual(struct ofono_modem *modem,
 				const struct ofono_network_operator *oper,
 				ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[128];
 
@@ -473,7 +474,7 @@ error:
 static void at_deregister(struct ofono_modem *modem, ofono_generic_cb_t cb,
 				void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -559,7 +560,7 @@ static void csq_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_signal_strength(struct ofono_modem *modem,
 				ofono_signal_strength_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -628,7 +629,7 @@ static void at_network_registration_initialized(gboolean ok, GAtResult *result,
 							gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (!ok) {
 		ofono_error("Unable to initialize Network Registration");
@@ -645,7 +646,7 @@ static void at_network_registration_initialized(gboolean ok, GAtResult *result,
 
 void at_network_registration_init(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	at->netreg = g_try_new0(struct netreg_data, 1);
 
@@ -659,7 +660,7 @@ void at_network_registration_init(struct ofono_modem *modem)
 
 void at_network_registration_exit(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (!at->netreg)
 		return;
diff --git a/drivers/atmodem/phonebook.c b/drivers/atmodem/phonebook.c
index d880c551..f9d7da19 100644
--- a/drivers/atmodem/phonebook.c
+++ b/drivers/atmodem/phonebook.c
@@ -31,6 +31,7 @@
 #include <glib.h>
 
 #include <ofono/log.h>
+#include <ofono/modem.h>
 #include "driver.h"
 #include "util.h"
 
@@ -102,7 +103,7 @@ static void at_cpbr_notify(GAtResult *result, gpointer user_data)
 {
 	struct cb_data *cbd = user_data;
 	struct ofono_modem *modem = cbd->modem;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	GAtResultIter iter;
 	int current;
 
@@ -202,7 +203,7 @@ static void at_cpbr_notify(GAtResult *result, gpointer user_data)
 static void export_failed(struct cb_data *cbd)
 {
 	struct ofono_modem *modem = cbd->modem;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	ofono_generic_cb_t cb = cbd->cb;
 
 	{
@@ -223,7 +224,7 @@ static void at_read_entries_cb(gboolean ok, GAtResult *result,
 {
 	struct cb_data *cbd = user_data;
 	struct ofono_modem *modem = cbd->modem;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	ofono_generic_cb_t cb = cbd->cb;
 	const char *charset;
 	struct ofono_error error;
@@ -247,7 +248,7 @@ static void at_read_entries_cb(gboolean ok, GAtResult *result,
 static void at_read_entries(struct cb_data *cbd)
 {
 	struct ofono_modem *modem = cbd->modem;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	char buf[32];
 
 	sprintf(buf, "AT+CPBR=%d,%d", at->pb->index_min, at->pb->index_max);
@@ -280,7 +281,7 @@ static void at_read_charset_cb(gboolean ok, GAtResult *result,
 {
 	struct cb_data *cbd = user_data;
 	struct ofono_modem *modem = cbd->modem;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	GAtResultIter iter;
 	const char *charset;
 	char buf[32];
@@ -320,7 +321,7 @@ static void at_list_indices_cb(gboolean ok, GAtResult *result,
 {
 	struct cb_data *cbd = user_data;
 	struct ofono_modem *modem = cbd->modem;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	GAtResultIter iter;
 
 	if (!ok)
@@ -356,7 +357,7 @@ static void at_select_storage_cb(gboolean ok, GAtResult *result,
 {
 	struct cb_data *cbd = user_data;
 	struct ofono_modem *modem = cbd->modem;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	dump_response("at_select_storage_cb", ok, result);
 
@@ -374,7 +375,7 @@ error:
 static void at_export_entries(struct ofono_modem *modem, const char *storage,
 				ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[32];
 
@@ -402,7 +403,7 @@ static struct ofono_phonebook_ops ops = {
 
 static void phonebook_not_supported(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	ofono_error("Phonebook not supported by this modem.  If this is in "
 			"error please submit patches to support this hardware");
@@ -459,7 +460,7 @@ static void at_list_charsets_cb(gboolean ok, GAtResult *result,
 					gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	gboolean in_list = FALSE;
 	GAtResultIter iter;
 	const char *charset;
@@ -516,7 +517,7 @@ error:
 
 static void at_list_charsets(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (g_at_chat_send(at->parser, "AT+CSCS=?", cscs_prefix,
 				at_list_charsets_cb, modem, NULL) > 0)
@@ -527,7 +528,7 @@ static void at_list_charsets(struct ofono_modem *modem)
 
 void at_phonebook_init(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	at->pb = phonebook_create();
 	at_list_charsets(modem);
@@ -535,7 +536,7 @@ void at_phonebook_init(struct ofono_modem *modem)
 
 void at_phonebook_exit(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (!at->pb)
 		return;
diff --git a/drivers/atmodem/sim.c b/drivers/atmodem/sim.c
index 41ed6a95..748cf6a2 100644
--- a/drivers/atmodem/sim.c
+++ b/drivers/atmodem/sim.c
@@ -31,6 +31,7 @@
 #include <glib.h>
 
 #include <ofono/log.h>
+#include <ofono/modem.h>
 #include "driver.h"
 
 #include "gatchat.h"
@@ -104,7 +105,7 @@ static void at_sim_read_info(struct ofono_modem *modem, int fileid,
 					ofono_sim_file_info_cb_t cb,
 					void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
@@ -175,7 +176,7 @@ static void at_sim_read_binary(struct ofono_modem *modem, int fileid,
 					int start, int length,
 					ofono_sim_read_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
@@ -203,7 +204,7 @@ static void at_sim_read_record(struct ofono_modem *modem, int fileid,
 					int record, int length,
 					ofono_sim_read_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
@@ -274,7 +275,7 @@ static void at_sim_update_binary(struct ofono_modem *modem, int fileid,
 					const unsigned char *value,
 					ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char *buf = g_try_new(char, 36 + length * 2);
 	int len, ret;
@@ -311,7 +312,7 @@ static void at_sim_update_record(struct ofono_modem *modem, int fileid,
 					const unsigned char *value,
 					ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char *buf = g_try_new(char, 36 + length * 2);
 	int len, ret;
@@ -347,7 +348,7 @@ static void at_sim_update_cyclic(struct ofono_modem *modem, int fileid,
 					int length, const unsigned char *value,
 					ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char *buf = g_try_new(char, 36 + length * 2);
 	int len, ret;
@@ -410,7 +411,7 @@ static void at_cimi_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_read_imsi(struct ofono_modem *modem, ofono_imsi_cb_t cb,
 			void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
diff --git a/drivers/atmodem/sms.c b/drivers/atmodem/sms.c
index c3a9fa61..39cc718b 100644
--- a/drivers/atmodem/sms.c
+++ b/drivers/atmodem/sms.c
@@ -31,6 +31,7 @@
 #include <glib.h>
 
 #include <ofono/log.h>
+#include <ofono/modem.h>
 #include "driver.h"
 #include "smsutil.h"
 #include "util.h"
@@ -108,7 +109,7 @@ static void at_csca_set(struct ofono_modem *modem,
 			const struct ofono_phone_number *sca,
 			ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[64];
 
@@ -183,7 +184,7 @@ err:
 static void at_csca_query(struct ofono_modem *modem, ofono_sca_query_cb_t cb,
 					void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -243,7 +244,7 @@ static void at_cmgs(struct ofono_modem *modem, unsigned char *pdu, int pdu_len,
 			int tpdu_len, int mms, ofono_sms_submit_cb_t cb,
 			void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[512];
 	int len;
@@ -326,7 +327,7 @@ static void at_cbm_notify(GAtResult *result, gpointer user_data)
 static void at_cds_notify(GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	int pdulen;
 	const char *pdu;
 	char buf[256];
@@ -353,7 +354,7 @@ static void at_cds_notify(GAtResult *result, gpointer user_data)
 static void at_cmt_notify(GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	const char *hexpdu;
 	long pdu_len;
 	int tpdu_len;
@@ -435,7 +436,7 @@ static void at_cmti_cpms_cb(gboolean ok, GAtResult *result, gpointer user_data)
 {
 	struct cpms_request *req = user_data;
 	struct ofono_modem *modem = req->modem;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	char buf[128];
 
 	if (!ok) {
@@ -456,7 +457,7 @@ static void at_cmti_cpms_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_cmti_notify(GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	const char *strstore;
 	int store;
 	GAtResultIter iter;
@@ -516,7 +517,7 @@ err:
 
 static void at_sms_initialized(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	g_at_chat_register(at->parser, "+CMTI:", at_cmti_notify, FALSE,
 				modem, NULL);
@@ -536,7 +537,7 @@ static void at_sms_initialized(struct ofono_modem *modem)
 
 static void at_sms_not_supported(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	ofono_error("SMS not supported by this modem.  If this is in error"
 			" please submit patches to support this hardware");
@@ -651,7 +652,7 @@ err:
 static void at_cnmi_query_cb(gboolean ok, GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	GAtResultIter iter;
 	int cnmi_opts[5]; /* See 27.005 Section 3.4.1 */
 	int opt;
@@ -702,7 +703,7 @@ out:
 
 static void at_query_cnmi(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	g_at_chat_send(at->parser, "AT+CNMI=?", cnmi_prefix,
 			at_cnmi_query_cb, modem, NULL);
@@ -711,7 +712,7 @@ static void at_query_cnmi(struct ofono_modem *modem)
 static void at_cpms_set_cb(gboolean ok, GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	dump_response("at_cpms_set_cb", ok, result);
 
@@ -731,7 +732,7 @@ static void at_cpms_set_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static gboolean set_cpms(gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	const char *store = storages[at->sms->store];
 	const char *incoming = storages[at->sms->incoming];
 	char buf[128];
@@ -746,7 +747,7 @@ static gboolean set_cpms(gpointer user_data)
 static void at_cmgf_set_cb(gboolean ok, GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	dump_response("at_cmgf_set_cb", ok, result);
 
@@ -769,7 +770,7 @@ static void at_cmgf_set_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static gboolean set_cmgf(gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	g_at_chat_send(at->parser, "AT+CMGF=0", cmgf_prefix,
 			at_cmgf_set_cb, modem, NULL);
@@ -780,7 +781,7 @@ static void at_cpms_query_cb(gboolean ok, GAtResult *result,
 				gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	gboolean supported = FALSE;
 
 	dump_response("cpms_query_cb", ok, result);
@@ -856,7 +857,7 @@ static void at_cmgf_query_cb(gboolean ok, GAtResult *result,
 				gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	gboolean supported = FALSE;
 
 	dump_response("cmgf_query_cb", ok, result);
@@ -891,7 +892,7 @@ static void at_csms_status_cb(gboolean ok, GAtResult *result,
 				gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	gboolean supported = FALSE;
 
 	dump_response("csms_status_cb", ok, result);
@@ -936,7 +937,7 @@ static void at_csms_set_cb(gboolean ok, GAtResult *result,
 				gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	g_at_chat_send(at->parser, "AT+CSMS?", csms_prefix,
 			at_csms_status_cb, modem, NULL);
@@ -946,7 +947,7 @@ static void at_csms_query_cb(gboolean ok, GAtResult *result,
 				gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	gboolean cnma_supported = FALSE;
 	GAtResultIter iter;
 	int status;
@@ -984,7 +985,7 @@ out:
 
 void at_sms_init(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	g_at_chat_send(at->parser, "AT+CSMS=?", csms_prefix,
 			at_csms_query_cb, modem, NULL);
@@ -992,7 +993,7 @@ void at_sms_init(struct ofono_modem *modem)
 
 void at_sms_exit(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (!at->sms)
 		return;
diff --git a/drivers/atmodem/ussd.c b/drivers/atmodem/ussd.c
index 1bae9ca8..02727155 100644
--- a/drivers/atmodem/ussd.c
+++ b/drivers/atmodem/ussd.c
@@ -31,6 +31,7 @@
 #include <glib.h>
 
 #include <ofono/log.h>
+#include <ofono/modem.h>
 #include "driver.h"
 #include "util.h"
 
@@ -56,7 +57,7 @@ static void cusd_request_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_ussd_request(struct ofono_modem *modem, const char *str,
 				ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	unsigned char *converted;
 	int dcs;
@@ -113,7 +114,7 @@ static void cusd_cancel_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_ussd_cancel(struct ofono_modem *modem,
 				ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
diff --git a/drivers/atmodem/voicecall.c b/drivers/atmodem/voicecall.c
index dd837e72..07e19870 100644
--- a/drivers/atmodem/voicecall.c
+++ b/drivers/atmodem/voicecall.c
@@ -31,6 +31,7 @@
 #include <glib.h>
 
 #include <ofono/log.h>
+#include <ofono/modem.h>
 #include "driver.h"
 
 #include "gatchat.h"
@@ -238,7 +239,7 @@ static GSList *parse_clcc(GAtResult *result)
 static void clcc_poll_cb(gboolean ok, GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	GSList *calls;
 	GSList *n, *o;
 	struct ofono_call *nc, *oc;
@@ -320,7 +321,7 @@ static void clcc_poll_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static gboolean poll_clcc(gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	g_at_chat_send(at->parser, "AT+CLCC", clcc_prefix,
 				clcc_poll_cb, modem, NULL);
@@ -333,7 +334,7 @@ static gboolean poll_clcc(gpointer user_data)
 static void generic_cb(gboolean ok, GAtResult *result, gpointer user_data)
 {
 	struct cb_data *cbd = user_data;
-	struct at_data *at = ofono_modem_userdata(cbd->modem);
+	struct at_data *at = ofono_modem_get_userdata(cbd->modem);
 	ofono_generic_cb_t cb = cbd->cb;
 	unsigned int released_status = GPOINTER_TO_UINT(cbd->user);
 	struct ofono_error error;
@@ -366,7 +367,7 @@ static void release_id_cb(gboolean ok, GAtResult *result,
 				gpointer user_data)
 {
 	struct cb_data *cbd = user_data;
-	struct at_data *at = ofono_modem_userdata(cbd->modem);
+	struct at_data *at = ofono_modem_get_userdata(cbd->modem);
 	ofono_generic_cb_t cb = cbd->cb;
 	struct ofono_error error;
 
@@ -386,7 +387,7 @@ static void release_id_cb(gboolean ok, GAtResult *result,
 static void atd_cb(gboolean ok, GAtResult *result, gpointer user_data)
 {
 	struct cb_data *cbd = user_data;
-	struct at_data *at = ofono_modem_userdata(cbd->modem);
+	struct at_data *at = ofono_modem_get_userdata(cbd->modem);
 	ofono_generic_cb_t cb = cbd->cb;
 	GAtResultIter iter;
 	const char *num;
@@ -446,7 +447,7 @@ static void at_dial(struct ofono_modem *modem,
 			enum ofono_clir_option clir, enum ofono_cug_option cug,
 			ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[256];
 
@@ -497,7 +498,7 @@ static void at_template(const char *cmd, struct ofono_modem *modem,
 			GAtResultFunc result_cb, unsigned int released_status,
 			ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -579,7 +580,7 @@ out:
 static void at_list_calls(struct ofono_modem *modem, ofono_call_list_cb_t cb,
 				void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 
 	if (!cbd)
@@ -629,7 +630,7 @@ static void at_release_all_active(struct ofono_modem *modem, ofono_generic_cb_t
 static void at_release_specific(struct ofono_modem *modem, int id,
 				ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	char buf[32];
 
@@ -708,7 +709,7 @@ static void vts_cb(gboolean ok, GAtResult *result, gpointer user_data)
 static void at_send_dtmf(struct ofono_modem *modem, const char *dtmf,
 			ofono_generic_cb_t cb, void *data)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct cb_data *cbd = cb_data_new(modem, cb, data);
 	int len = strlen(dtmf);
 	int s;
@@ -750,7 +751,7 @@ error:
 static void ring_notify(GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	struct ofono_call *call;
 
 	dump_response("ring_notify", TRUE, result);
@@ -776,7 +777,7 @@ static void ring_notify(GAtResult *result, gpointer user_data)
 static void cring_notify(GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	GAtResultIter iter;
 	const char *line;
 	int type;
@@ -822,7 +823,7 @@ static void cring_notify(GAtResult *result, gpointer user_data)
 static void clip_notify(GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	GAtResultIter iter;
 	const char *num;
 	int type, validity;
@@ -888,7 +889,7 @@ static void clip_notify(GAtResult *result, gpointer user_data)
 static void ccwa_notify(GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 	GAtResultIter iter;
 	const char *num;
 	int num_type, validity, cls;
@@ -943,7 +944,7 @@ static void ccwa_notify(GAtResult *result, gpointer user_data)
 static void no_carrier_notify(GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (at->voicecall->poll_clcc)
 		g_at_chat_send(at->parser, "AT+CLCC", clcc_prefix,
@@ -953,7 +954,7 @@ static void no_carrier_notify(GAtResult *result, gpointer user_data)
 static void no_answer_notify(GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (at->voicecall->poll_clcc)
 		g_at_chat_send(at->parser, "AT+CLCC", clcc_prefix,
@@ -963,7 +964,7 @@ static void no_answer_notify(GAtResult *result, gpointer user_data)
 static void busy_notify(GAtResult *result, gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	/* Call was rejected, most likely due to network congestion
 	 * or UDUB on the other side
@@ -1057,7 +1058,7 @@ static void at_voicecall_initialized(gboolean ok, GAtResult *result,
 					gpointer user_data)
 {
 	struct ofono_modem *modem = user_data;
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	ofono_debug("voicecall_init: registering to notifications");
 
@@ -1089,7 +1090,7 @@ static void at_voicecall_initialized(gboolean ok, GAtResult *result,
 
 void at_voicecall_init(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	at->voicecall = g_try_new0(struct voicecall_data, 1);
 
@@ -1110,7 +1111,7 @@ void at_voicecall_init(struct ofono_modem *modem)
 
 void at_voicecall_exit(struct ofono_modem *modem)
 {
-	struct at_data *at = ofono_modem_userdata(modem);
+	struct at_data *at = ofono_modem_get_userdata(modem);
 
 	if (!at->voicecall)
 		return;
diff --git a/drivers/isimodem/isimodem.c b/drivers/isimodem/isimodem.c
index 6f7bcc66..d4eaa4e1 100644
--- a/drivers/isimodem/isimodem.c
+++ b/drivers/isimodem/isimodem.c
@@ -35,6 +35,7 @@
 
 #include <ofono/plugin.h>
 #include <ofono/log.h>
+#include <ofono/modem.h>
 #include "driver.h"
 
 #include "isi.h"
diff --git a/include/modem.h b/include/modem.h
index a467da27..2c2db2eb 100644
--- a/include/modem.h
+++ b/include/modem.h
@@ -26,6 +26,8 @@
 extern "C" {
 #endif
 
+struct ofono_modem;
+
 void ofono_modem_add_interface(struct ofono_modem *modem,
 				const char *interface);
 
@@ -34,6 +36,9 @@ void ofono_modem_remove_interface(struct ofono_modem *modem,
 
 const char *ofono_modem_get_path(struct ofono_modem *modem);
 
+void ofono_modem_set_userdata(struct ofono_modem *modem, void *data);
+void *ofono_modem_get_userdata(struct ofono_modem *modem);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/driver.h b/src/driver.h
index 928c20a2..f05961be 100644
--- a/src/driver.h
+++ b/src/driver.h
@@ -193,9 +193,6 @@ struct ofono_modem_attribute_ops {
 struct ofono_modem *ofono_modem_register(struct ofono_modem_attribute_ops *ops);
 int ofono_modem_unregister(struct ofono_modem *modem);
 
-void ofono_modem_set_userdata(struct ofono_modem *modem, void *data);
-void *ofono_modem_userdata(struct ofono_modem *modem);
-
 /* Network related functions, including registration status, operator selection
  * and signal strength indicators.
  *
diff --git a/src/modem.c b/src/modem.c
index 904636fc..2334b539 100644
--- a/src/modem.c
+++ b/src/modem.c
@@ -85,7 +85,7 @@ void ofono_modem_set_userdata(struct ofono_modem *modem, void *userdata)
 		modem->userdata = userdata;
 }
 
-void *ofono_modem_userdata(struct ofono_modem *modem)
+void *ofono_modem_get_userdata(struct ofono_modem *modem)
 {
 	if (modem)
 		return modem->userdata;