n_gsm: introduce enum gsm_dlci_mode

gsm_dlci->mode is clearly an enumeration. So introduce one and use it
-- compiler now checks if valid values are assigned to the field.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200219084949.28074-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 1d0a140..7fee5a5 100644 (file)
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -107,6 +107,11 @@ enum gsm_dlci_state {
        DLCI_CLOSING,           /* Sending DISC not seen UA/DM */
 };
 
+enum gsm_dlci_mode {
+       DLCI_MODE_ABM,          /* Normal Asynchronous Balanced Mode */
+       DLCI_MODE_ADM,          /* Asynchronous Disconnected Mode */
+};
+
 /*
  *     Each active data link has a gsm_dlci structure associated which ties
  *     the link layer to an optional tty (if the tty side is open). To avoid
@@ -124,9 +129,7 @@ struct gsm_dlci {
        struct mutex mutex;
 
        /* Link layer */
-       int mode;
-#define DLCI_MODE_ABM          0       /* Normal Asynchronous Balanced Mode */
-#define DLCI_MODE_ADM          1       /* Asynchronous Disconnected Mode */
+       enum gsm_dlci_mode mode;
        spinlock_t lock;        /* Protects the internal state */
        struct timer_list t1;   /* Retransmit timer for SABM and UA */
        int retries;