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]>
---
Changes since v1:
* updated bullet numbering
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
Guessing the base 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 a ioctl.
Signed-off-by: Martin Hundebøll <[email protected]>
---
Changes since v1:
* use put_user() instead of copy_to_user()
* add missing opening quote
Documentation/serial/n_gsm.rst | 12 ++++++++++--
drivers/tty/n_gsm.c | 4 ++++
include/uapi/linux/gsmmux.h | 2 ++
3 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/Documentation/serial/n_gsm.rst b/Documentation/serial/n_gsm.rst
index 0ba731ab00b2..4a52499567f5 100644
--- a/Documentation/serial/n_gsm.rst
+++ b/Documentation/serial/n_gsm.rst
@@ -18,10 +18,12 @@ 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 <linux/gsmmux.h>
#include <linux/tty.h>
#define DEFAULT_SPEED B115200
@@ -30,6 +32,7 @@ Major parts of the initialization program :
int ldisc = N_GSM0710;
struct gsm_config c;
struct termios configuration;
+ int base;
/* open the serial port connected to the modem */
fd = open(SERIAL_PORT, O_RDWR | O_NOCTTY | O_NDELAY);
@@ -58,19 +61,24 @@ Major parts of the initialization program :
c.mtu = 127;
/* set the new configuration */
ioctl(fd, GSMIOC_SETCONF, &c);
+ /* get base gsmtty device node */
+ ioctl(fd, GSMIOC_GETBASE, &base);
+ /* the base node is used for mux control by the driver */
+ printf("first muxed line: /dev/gsmtty%i\n", base + 1);
+
/* 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 cba06063c44a..e7aea4ccbebd 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2612,6 +2612,7 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
{
struct gsm_config c;
struct gsm_mux *gsm = tty->disc_data;
+ int base;
switch (cmd) {
case GSMIOC_GETCONF:
@@ -2623,6 +2624,9 @@ 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_GETBASE:
+ base = mux_num_to_base(gsm);
+ return put_user(base, (int __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..6eb63be3ed9e 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_GETBASE _IOR('G', 4, int)
#endif
--
2.22.0
Make it obvious how the gsm mux number relates to the virtual tty lines
by using helper function instead of shifting 6 bits.
Signed-off-by: Martin Hundebøll <[email protected]>
---
drivers/tty/n_gsm.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index c4e16b31f9ab..cba06063c44a 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 int mux_num_to_base(struct gsm_mux *gsm)
+{
+ return gsm->num * NUM_DLCI;
+}
+
+static inline unsigned int mux_line_to_num(int line)
+{
+ return line / NUM_DLCI;
+}
+
/**
* gsm_alloc_mux - allocate a mux
*
@@ -2361,7 +2371,7 @@ 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);
}
@@ -2380,7 +2390,7 @@ 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 */
+ int base = mux_num_to_base(gsm); /* Base for this MUX */
WARN_ON(tty != gsm->tty);
for (i = 1; i < NUM_DLCI; i++)
@@ -2908,7 +2918,7 @@ 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
On 09. 07. 19, 8:46, Martin Hundebøll wrote:
> @@ -2623,6 +2624,9 @@ 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_GETBASE:
> + base = mux_num_to_base(gsm);
> + return put_user(base, (int __user *)arg);
I am not sure, but do you need the local variable at all?
> default:
> return n_tty_ioctl_helper(tty, file, cmd, arg);
> }
--
js
suse labs
On 09/07/2019 08.49, Jiri Slaby wrote:
> On 09. 07. 19, 8:46, Martin Hundebøll wrote:
>> @@ -2623,6 +2624,9 @@ 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_GETBASE:
>> + base = mux_num_to_base(gsm);
>> + return put_user(base, (int __user *)arg);
> I am not sure, but do you need the local variable at all?
No, I kept it around just to avoid too many parenthesis in the
put_user() call.
Your call.
// Martin
On Tue, 9 Jul 2019 08:46:32 +0200
Martin Hundebøll <[email protected]> wrote:
> Make it obvious how the gsm mux number relates to the virtual tty lines
> by using helper function instead of shifting 6 bits.
>
> Signed-off-by: Martin Hundebøll <[email protected]>
> ---
> drivers/tty/n_gsm.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
> index c4e16b31f9ab..cba06063c44a 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 int mux_num_to_base(struct gsm_mux *gsm)
> +{
> + return gsm->num * NUM_DLCI;
> +}
> +
> +static inline unsigned int mux_line_to_num(int line)
> +{
> + return line / NUM_DLCI;
If you are going to convert shifts to multiply and divide then used
unsigned maths so the compiler can optimize it nicely on some of the low
end processors.
Alan