From d50f6dcaf22a3234a65ae4f6087173e66b7fff56 Mon Sep 17 00:00:00 2001 From: Russ Gorby Date: Tue, 14 Jun 2011 13:35:32 -0700 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/n_gsm.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 09e8c7d53af3..b288ff6cb812 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -169,6 +169,7 @@ struct gsm_control { 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 @@ struct gsm_mux { 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 @@ int gsm_activate_mux(struct gsm_mux *gsm) 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_output(struct gsm_mux *gsm, u8 *data, int len) 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 int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) 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 @@ static int gsmtty_break_ctl(struct tty_struct *tty, int state) 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 = { -- 2.20.1