The n_gsm driver handles registration of /dev/gsmttyX nodes, so there's
no need to do mknod manually.
Signed-off-by: Martin Hundebøll <[email protected]>
---
Documentation/serial/n_gsm.rst | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)
diff --git a/Documentation/serial/n_gsm.rst b/Documentation/serial/n_gsm.rst
index f3ad9fd26408..4f37198423f7 100644
--- a/Documentation/serial/n_gsm.rst
+++ b/Documentation/serial/n_gsm.rst
@@ -63,24 +63,14 @@ Major parts of the initialization program :
daemon(0,0);
pause();
-4. create the devices corresponding to the "virtual" serial ports (take care,
- each modem has its configuration and some DLC have dedicated functions,
- for example GPS), starting with minor 1 (DLC0 is reserved for the management
- of the mux)::
-
- MAJOR=`cat /proc/devices |grep gsmtty | awk '{print $1}`
- for i in `seq 1 4`; do
- mknod /dev/ttygsm$i c $MAJOR $i
- done
-
-5. use these devices as plain serial ports.
+4. use these devices as plain serial ports.
for example, it's possible:
- and to use gnokii to send / receive SMS on ttygsm1
- to use ppp to establish a datalink on ttygsm2
-6. first close all virtual ports before closing the physical port.
+5. first close all virtual ports before closing the physical port.
Note that after closing the physical port the modem is still in multiplexing
mode. This may prevent a successful re-opening of the port later. To avoid
--
2.22.0
There is no reason to gues the line discipline number when it is
available from tty.h
Signed-off-by: Martin Hundebøll <[email protected]>
---
Documentation/serial/n_gsm.rst | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Documentation/serial/n_gsm.rst b/Documentation/serial/n_gsm.rst
index 4f37198423f7..0ba731ab00b2 100644
--- a/Documentation/serial/n_gsm.rst
+++ b/Documentation/serial/n_gsm.rst
@@ -23,7 +23,7 @@ Major parts of the initialization program :
(a good starting point is util-linux-ng/sys-utils/ldattach.c)::
#include <linux/gsmmux.h>
- #define N_GSM0710 21 /* GSM 0710 Mux */
+ #include <linux/tty.h>
#define DEFAULT_SPEED B115200
#define SERIAL_PORT /dev/ttyS0
--
2.22.0
Make it obvious how the gsm mux number relates to the virtual tty lines
by using helper functions instead of shifting 6 bits.
Signed-off-by: Martin Hundebøll <[email protected]>
---
Changes since v2:
* use unsigned integers in both helper functions
drivers/tty/n_gsm.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index c4e16b31f9ab..a60be591f1fc 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2171,6 +2171,16 @@ static inline void mux_put(struct gsm_mux *gsm)
kref_put(&gsm->ref, gsm_free_muxr);
}
+static inline unsigned int mux_num_to_base(struct gsm_mux *gsm)
+{
+ return gsm->num * NUM_DLCI;
+}
+
+static inline unsigned int mux_line_to_num(unsigned int line)
+{
+ return line / NUM_DLCI;
+}
+
/**
* gsm_alloc_mux - allocate a mux
*
@@ -2351,7 +2361,8 @@ 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, i, base;
+ unsigned int base;
+ int ret, i;
gsm->tty = tty_kref_get(tty);
gsm->output = gsmld_output;
@@ -2361,7 +2372,7 @@ static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
else {
/* Don't register device 0 - this is the control channel and not
a usable tty interface */
- base = gsm->num << 6; /* Base for this MUX */
+ base = mux_num_to_base(gsm); /* Base for this MUX */
for (i = 1; i < NUM_DLCI; i++)
tty_register_device(gsm_tty_driver, base + i, NULL);
}
@@ -2379,8 +2390,8 @@ 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)
{
+ unsigned int base = mux_num_to_base(gsm); /* Base for this MUX */
int i;
- int base = gsm->num << 6; /* Base for this MUX */
WARN_ON(tty != gsm->tty);
for (i = 1; i < NUM_DLCI; i++)
@@ -2908,7 +2919,7 @@ static int gsmtty_install(struct tty_driver *driver, struct tty_struct *tty)
struct gsm_mux *gsm;
struct gsm_dlci *dlci;
unsigned int line = tty->index;
- unsigned int mux = line >> 6;
+ unsigned int mux = mux_line_to_num(line);
bool alloc = false;
int ret;
--
2.22.0
Guessing the first tty for a gsm0710 multiplexed serial device is not
currently possible, which makes it racy to use with multiple modems.
Add a way to map the physical serial tty to its related mux devices
using an ioctl.
Signed-off-by: Martin Hundebøll <[email protected]>
---
Changes since v2:
* rename IOCTL from GSMIOC_GETBASE to GSMIOC_GETFIRST
* return first usable line instead of private control line
* return uint32_t instead of int
Changes since v1:
* use put_user() instead of copy_to_user()
* add missing opening quote
Documentation/serial/n_gsm.rst | 11 +++++++++--
drivers/tty/n_gsm.c | 4 ++++
include/uapi/linux/gsmmux.h | 2 ++
3 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/Documentation/serial/n_gsm.rst b/Documentation/serial/n_gsm.rst
index 0ba731ab00b2..286e7ff4d2d9 100644
--- a/Documentation/serial/n_gsm.rst
+++ b/Documentation/serial/n_gsm.rst
@@ -18,10 +18,13 @@ How to use it
2. switch the serial line to using the n_gsm line discipline by using
TIOCSETD ioctl,
3. configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl,
+4. obtain base gsmtty number for the used serial port,
Major parts of the initialization program :
(a good starting point is util-linux-ng/sys-utils/ldattach.c)::
+ #include <stdio.h>
+ #include <stdint.h>
#include <linux/gsmmux.h>
#include <linux/tty.h>
#define DEFAULT_SPEED B115200
@@ -30,6 +33,7 @@ Major parts of the initialization program :
int ldisc = N_GSM0710;
struct gsm_config c;
struct termios configuration;
+ uint32_t first;
/* open the serial port connected to the modem */
fd = open(SERIAL_PORT, O_RDWR | O_NOCTTY | O_NDELAY);
@@ -58,19 +62,22 @@ Major parts of the initialization program :
c.mtu = 127;
/* set the new configuration */
ioctl(fd, GSMIOC_SETCONF, &c);
+ /* get first gsmtty device node */
+ ioctl(fd, GSMIOC_GETFIRST, &first);
+ printf("first muxed line: /dev/gsmtty%i\n", first);
/* and wait for ever to keep the line discipline enabled */
daemon(0,0);
pause();
-4. use these devices as plain serial ports.
+5. use these devices as plain serial ports.
for example, it's possible:
- and to use gnokii to send / receive SMS on ttygsm1
- to use ppp to establish a datalink on ttygsm2
-5. first close all virtual ports before closing the physical port.
+6. first close all virtual ports before closing the physical port.
Note that after closing the physical port the modem is still in multiplexing
mode. This may prevent a successful re-opening of the port later. To avoid
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index a60be591f1fc..dac98f3ead3d 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2613,6 +2613,7 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
{
struct gsm_config c;
struct gsm_mux *gsm = tty->disc_data;
+ unsigned int base;
switch (cmd) {
case GSMIOC_GETCONF:
@@ -2624,6 +2625,9 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
if (copy_from_user(&c, (void *)arg, sizeof(c)))
return -EFAULT;
return gsm_config(gsm, &c);
+ case GSMIOC_GETFIRST:
+ base = mux_num_to_base(gsm);
+ return put_user(base + 1, (uint32_t __user *)arg);
default:
return n_tty_ioctl_helper(tty, file, cmd, arg);
}
diff --git a/include/uapi/linux/gsmmux.h b/include/uapi/linux/gsmmux.h
index 101d3c469acb..e292869245dc 100644
--- a/include/uapi/linux/gsmmux.h
+++ b/include/uapi/linux/gsmmux.h
@@ -37,5 +37,7 @@ struct gsm_netconfig {
#define GSMIOC_ENABLE_NET _IOW('G', 2, struct gsm_netconfig)
#define GSMIOC_DISABLE_NET _IO('G', 3)
+/* get the base tty number for a configured gsmmux tty */
+#define GSMIOC_GETFIRST _IOR('G', 4, uint32_t)
#endif
--
2.22.0
On Wed, Jul 10, 2019 at 09:26:56PM +0200, Martin Hundeb?ll wrote:
> Guessing the first tty for a gsm0710 multiplexed serial device is not
> currently possible, which makes it racy to use with multiple modems.
>
> Add a way to map the physical serial tty to its related mux devices
> using an ioctl.
>
> Signed-off-by: Martin Hundeb?ll <[email protected]>
> ---
>
> Changes since v2:
> * rename IOCTL from GSMIOC_GETBASE to GSMIOC_GETFIRST
> * return first usable line instead of private control line
> * return uint32_t instead of int
>
> Changes since v1:
> * use put_user() instead of copy_to_user()
> * add missing opening quote
>
> Documentation/serial/n_gsm.rst | 11 +++++++++--
> drivers/tty/n_gsm.c | 4 ++++
> include/uapi/linux/gsmmux.h | 2 ++
> 3 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/serial/n_gsm.rst b/Documentation/serial/n_gsm.rst
> index 0ba731ab00b2..286e7ff4d2d9 100644
> --- a/Documentation/serial/n_gsm.rst
> +++ b/Documentation/serial/n_gsm.rst
> @@ -18,10 +18,13 @@ How to use it
> 2. switch the serial line to using the n_gsm line discipline by using
> TIOCSETD ioctl,
> 3. configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl,
> +4. obtain base gsmtty number for the used serial port,
As this file is in .rst format, do we need the enumerated list anymore?
Just a meta-comment...
>
> Major parts of the initialization program :
> (a good starting point is util-linux-ng/sys-utils/ldattach.c)::
>
> + #include <stdio.h>
> + #include <stdint.h>
> #include <linux/gsmmux.h>
> #include <linux/tty.h>
> #define DEFAULT_SPEED B115200
> @@ -30,6 +33,7 @@ Major parts of the initialization program :
> int ldisc = N_GSM0710;
> struct gsm_config c;
> struct termios configuration;
> + uint32_t first;
>
> /* open the serial port connected to the modem */
> fd = open(SERIAL_PORT, O_RDWR | O_NOCTTY | O_NDELAY);
> @@ -58,19 +62,22 @@ Major parts of the initialization program :
> c.mtu = 127;
> /* set the new configuration */
> ioctl(fd, GSMIOC_SETCONF, &c);
> + /* get first gsmtty device node */
> + ioctl(fd, GSMIOC_GETFIRST, &first);
> + printf("first muxed line: /dev/gsmtty%i\n", first);
>
> /* and wait for ever to keep the line discipline enabled */
> daemon(0,0);
> pause();
>
> -4. use these devices as plain serial ports.
> +5. use these devices as plain serial ports.
>
> for example, it's possible:
>
> - and to use gnokii to send / receive SMS on ttygsm1
> - to use ppp to establish a datalink on ttygsm2
>
> -5. first close all virtual ports before closing the physical port.
> +6. first close all virtual ports before closing the physical port.
>
> Note that after closing the physical port the modem is still in multiplexing
> mode. This may prevent a successful re-opening of the port later. To avoid
> diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
> index a60be591f1fc..dac98f3ead3d 100644
> --- a/drivers/tty/n_gsm.c
> +++ b/drivers/tty/n_gsm.c
> @@ -2613,6 +2613,7 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
> {
> struct gsm_config c;
> struct gsm_mux *gsm = tty->disc_data;
> + unsigned int base;
>
> switch (cmd) {
> case GSMIOC_GETCONF:
> @@ -2624,6 +2625,9 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
> if (copy_from_user(&c, (void *)arg, sizeof(c)))
> return -EFAULT;
> return gsm_config(gsm, &c);
> + case GSMIOC_GETFIRST:
> + base = mux_num_to_base(gsm);
> + return put_user(base + 1, (uint32_t __user *)arg);
> default:
> return n_tty_ioctl_helper(tty, file, cmd, arg);
> }
> diff --git a/include/uapi/linux/gsmmux.h b/include/uapi/linux/gsmmux.h
> index 101d3c469acb..e292869245dc 100644
> --- a/include/uapi/linux/gsmmux.h
> +++ b/include/uapi/linux/gsmmux.h
> @@ -37,5 +37,7 @@ struct gsm_netconfig {
> #define GSMIOC_ENABLE_NET _IOW('G', 2, struct gsm_netconfig)
> #define GSMIOC_DISABLE_NET _IO('G', 3)
>
> +/* get the base tty number for a configured gsmmux tty */
> +#define GSMIOC_GETFIRST _IOR('G', 4, uint32_t)
Variables that cross the boundry from user/kernel should use the correct
type. That would be "__u32" here.
thanks.
greg k-h