diff --git a/drivers/bluetooth/btwilink.c b/drivers/bluetooth/btwilink.c
index 24a652f9252b..485281b3f167 100644
--- a/drivers/bluetooth/btwilink.c
+++ b/drivers/bluetooth/btwilink.c
@@ -51,7 +51,7 @@
  */
 struct ti_st {
 	struct hci_dev *hdev;
-	char reg_status;
+	int reg_status;
 	long (*st_write) (struct sk_buff *);
 	struct completion wait_reg_completion;
 };
@@ -83,7 +83,7 @@ static inline void ti_st_tx_complete(struct ti_st *hst, int pkt_type)
  * status.ti_st_open() function will wait for signal from this
  * API when st_register() function returns ST_PENDING.
  */
-static void st_reg_completion_cb(void *priv_data, char data)
+static void st_reg_completion_cb(void *priv_data, int data)
 {
 	struct ti_st *lhst = priv_data;
 
diff --git a/drivers/media/radio/wl128x/fmdrv_common.c b/drivers/media/radio/wl128x/fmdrv_common.c
index 3f9e6df7d837..642b89c66bcb 100644
--- a/drivers/media/radio/wl128x/fmdrv_common.c
+++ b/drivers/media/radio/wl128x/fmdrv_common.c
@@ -1472,7 +1472,7 @@ static long fm_st_receive(void *arg, struct sk_buff *skb)
  * Called by ST layer to indicate protocol registration completion
  * status.
  */
-static void fm_st_reg_comp_cb(void *arg, char data)
+static void fm_st_reg_comp_cb(void *arg, int data)
 {
 	struct fmdev *fmdev;
 
diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
index dcdbd58672cc..00051590e00f 100644
--- a/drivers/misc/ti-st/st_core.c
+++ b/drivers/misc/ti-st/st_core.c
@@ -141,7 +141,7 @@ static void st_send_frame(unsigned char chnl_id, struct st_data_s *st_gdata)
  * This function is being called with spin lock held, protocol drivers are
  * only expected to complete their waits and do nothing more than that.
  */
-static void st_reg_complete(struct st_data_s *st_gdata, char err)
+static void st_reg_complete(struct st_data_s *st_gdata, int err)
 {
 	unsigned char i = 0;
 	pr_info(" %s ", __func__);
diff --git a/drivers/nfc/nfcwilink.c b/drivers/nfc/nfcwilink.c
index f81e500e7650..3fbd18b8e473 100644
--- a/drivers/nfc/nfcwilink.c
+++ b/drivers/nfc/nfcwilink.c
@@ -94,7 +94,7 @@ struct nfcwilink {
 	struct nci_dev			*ndev;
 	unsigned long			flags;
 
-	char				st_register_cb_status;
+	int				st_register_cb_status;
 	long				(*st_write) (struct sk_buff *);
 
 	struct completion		completed;
@@ -320,7 +320,7 @@ exit:
 }
 
 /* Called by ST when registration is complete */
-static void nfcwilink_register_complete(void *priv_data, char data)
+static void nfcwilink_register_complete(void *priv_data, int data)
 {
 	struct nfcwilink *drv = priv_data;
 
diff --git a/include/linux/ti_wilink_st.h b/include/linux/ti_wilink_st.h
index 0a0d56834c8e..f2293028ab9d 100644
--- a/include/linux/ti_wilink_st.h
+++ b/include/linux/ti_wilink_st.h
@@ -71,7 +71,7 @@ struct st_proto_s {
 	enum proto_type type;
 	long (*recv) (void *, struct sk_buff *);
 	unsigned char (*match_packet) (const unsigned char *data);
-	void (*reg_complete_cb) (void *, char data);
+	void (*reg_complete_cb) (void *, int data);
 	long (*write) (struct sk_buff *skb);
 	void *priv_data;