179 lines
3.8 KiB
C
179 lines
3.8 KiB
C
#include <tty.h>
|
|
#include <tty_ldisc.h>
|
|
|
|
#define DBG_TAG "TTY_LDISC"
|
|
#ifdef RT_TTY_DEBUG
|
|
#define DBG_LVL DBG_LOG
|
|
#else
|
|
#define DBG_LVL DBG_INFO
|
|
#endif /* RT_TTY_DEBUG */
|
|
#include <rtdbg.h>
|
|
|
|
extern struct tty_ldisc_ops n_tty_ops;
|
|
static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS] = {
|
|
&n_tty_ops, /* N_TTY = 0 */
|
|
};
|
|
|
|
static struct rt_spinlock _spinlock = RT_SPINLOCK_INIT;
|
|
|
|
static struct tty_ldisc_ops *get_ldops(int disc)
|
|
{
|
|
struct tty_ldisc_ops *ldops = RT_NULL;
|
|
rt_base_t level = 0;
|
|
level = rt_spin_lock_irqsave(&_spinlock);
|
|
ldops = tty_ldiscs[disc];
|
|
if (ldops)
|
|
{
|
|
ldops->refcount++;
|
|
}
|
|
rt_spin_unlock_irqrestore(&_spinlock, level);
|
|
return ldops;
|
|
}
|
|
|
|
static void put_ldops(struct tty_ldisc_ops *ldops)
|
|
{
|
|
rt_base_t level = 0;
|
|
|
|
level = rt_spin_lock_irqsave(&_spinlock);
|
|
ldops->refcount--;
|
|
rt_spin_unlock_irqrestore(&_spinlock, level);
|
|
}
|
|
|
|
static struct tty_ldisc *tty_ldisc_get(struct tty_struct *tty, int disc)
|
|
{
|
|
struct tty_ldisc *ld = RT_NULL;
|
|
struct tty_ldisc_ops *ldops = RT_NULL;
|
|
|
|
if (disc < N_TTY || disc >= NR_LDISCS)
|
|
{
|
|
return RT_NULL;
|
|
}
|
|
|
|
ldops = get_ldops(disc);
|
|
if (ldops == RT_NULL)
|
|
{
|
|
LOG_E("tty ldisc get error\n");
|
|
return RT_NULL;
|
|
}
|
|
|
|
ld = rt_malloc(sizeof(struct tty_ldisc));
|
|
if (ld == RT_NULL)
|
|
{
|
|
ldops->refcount--;
|
|
return RT_NULL;
|
|
}
|
|
|
|
ld->ops = ldops;
|
|
ld->tty = tty;
|
|
|
|
return ld;
|
|
}
|
|
|
|
/**
|
|
* tty_ldisc_put - release the ldisc
|
|
*
|
|
* Complement of tty_ldisc_get().
|
|
*/
|
|
static void tty_ldisc_put(struct tty_ldisc *ld)
|
|
{
|
|
if (ld)
|
|
{
|
|
put_ldops(ld->ops);
|
|
rt_free(ld);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tty_ldisc_close - close a line discipline
|
|
* @tty: tty we are opening the ldisc on
|
|
* @ld: discipline to close
|
|
*
|
|
* A helper close method. Also a convenient debugging and check
|
|
* point.
|
|
*/
|
|
static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
|
|
{
|
|
if (ld && ld->ops->close)
|
|
{
|
|
ld->ops->close(tty);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tty_ldisc_kill - teardown ldisc
|
|
* @tty: tty being released
|
|
*
|
|
* Perform final close of the ldisc and reset tty->ldisc
|
|
*/
|
|
void tty_ldisc_kill(struct tty_struct *tty)
|
|
{
|
|
if (tty && tty->ldisc)
|
|
{
|
|
/*
|
|
* Now kill off the ldisc
|
|
*/
|
|
tty_ldisc_close(tty, tty->ldisc);
|
|
tty_ldisc_put(tty->ldisc);
|
|
/* Force an oops if we mess this up */
|
|
tty->ldisc = NULL;
|
|
}
|
|
}
|
|
|
|
int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc)
|
|
{
|
|
int ret = 0;
|
|
rt_base_t level = 0;
|
|
|
|
if (disc < N_TTY || disc >= NR_LDISCS)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
level = rt_spin_lock_irqsave(&_spinlock);
|
|
tty_ldiscs[disc] = new_ldisc;
|
|
new_ldisc->num = disc;
|
|
new_ldisc->refcount = 0;
|
|
rt_spin_unlock_irqrestore(&_spinlock, level);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* tty_ldisc_release - release line discipline
|
|
* @tty: tty being shut down (or one end of pty pair)
|
|
*
|
|
* Called during the final close of a tty or a pty pair in order to shut
|
|
* down the line discpline layer. On exit, each tty's ldisc is NULL.
|
|
*/
|
|
|
|
void tty_ldisc_release(struct tty_struct *tty)
|
|
{
|
|
struct tty_struct *o_tty = tty->other_struct;
|
|
|
|
/*
|
|
* Shutdown this line discipline. As this is the final close,
|
|
* it does not race with the set_ldisc code path.
|
|
*/
|
|
tty_ldisc_kill(tty);
|
|
if (o_tty)
|
|
{
|
|
tty_ldisc_kill(o_tty);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* tty_ldisc_init - ldisc setup for new tty
|
|
* @tty: tty being allocated
|
|
*
|
|
* Set up the line discipline objects for a newly allocated tty. Note that
|
|
* the tty structure is not completely set up when this call is made.
|
|
*/
|
|
|
|
void tty_ldisc_init(struct tty_struct *tty)
|
|
{
|
|
if (tty)
|
|
{
|
|
tty->ldisc = tty_ldisc_get(tty, N_TTY);
|
|
}
|
|
}
|