tty: n_gsm: expose gsmtty device nodes at ldisc open time
The n_gsm driver being an ldisc, does not provide a convenient method
e.g. udev to create the tty device nodes automatically when the ldisc
is opened.
The TTY device nodes are now created via calls to tty_register_device
from the ldisc open.
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 09e8c7d..b288ff6 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -169,6 +169,7 @@
struct gsm_mux {
struct tty_struct *tty; /* The tty our ldisc is bound to */
spinlock_t lock;
+ unsigned int num;
/* Events on the GSM channel */
wait_queue_head_t event;
@@ -250,6 +251,8 @@
static struct gsm_mux *gsm_mux[MAX_MUX]; /* GSM muxes */
static spinlock_t gsm_mux_lock;
+static struct tty_driver *gsm_tty_driver;
+
/*
* This section of the driver logic implements the GSM encodings
* both the basic and the 'advanced'. Reliable transport is not
@@ -1996,6 +1999,7 @@
spin_lock(&gsm_mux_lock);
for (i = 0; i < MAX_MUX; i++) {
if (gsm_mux[i] == NULL) {
+ gsm->num = i;
gsm_mux[i] = gsm;
break;
}
@@ -2101,13 +2105,20 @@
static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
{
- int ret;
+ int ret, i;
+ int base = gsm->num << 6; /* Base for this MUX */
gsm->tty = tty_kref_get(tty);
gsm->output = gsmld_output;
ret = gsm_activate_mux(gsm);
if (ret != 0)
tty_kref_put(gsm->tty);
+ else {
+ /* Don't register device 0 - this is the control channel and not
+ a usable tty interface */
+ for (i = 1; i < NUM_DLCI; i++)
+ tty_register_device(gsm_tty_driver, base + i, NULL);
+ }
return ret;
}
@@ -2122,7 +2133,12 @@
static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
{
+ int i;
+ int base = gsm->num << 6; /* Base for this MUX */
+
WARN_ON(tty != gsm->tty);
+ for (i = 1; i < NUM_DLCI; i++)
+ tty_unregister_device(gsm_tty_driver, base + i);
gsm_cleanup_mux(gsm);
tty_kref_put(gsm->tty);
gsm->tty = NULL;
@@ -2712,7 +2728,6 @@
return gsmtty_modem_update(dlci, encode);
}
-static struct tty_driver *gsm_tty_driver;
/* Virtual ttys for the demux */
static const struct tty_operations gsmtty_ops = {