1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
102 lines
2.3 KiB
C
102 lines
2.3 KiB
C
/*
|
|
pseudo.h (c) 1997-8 Grant R. Guenther <grant@torque.net>
|
|
Under the terms of the GNU General Public License.
|
|
|
|
This is the "pseudo-interrupt" logic for parallel port drivers.
|
|
|
|
This module is #included into each driver. It makes one
|
|
function available:
|
|
|
|
ps_set_intr( void (*continuation)(void),
|
|
int (*ready)(void),
|
|
int timeout,
|
|
int nice )
|
|
|
|
Which will arrange for ready() to be evaluated frequently and
|
|
when either it returns true, or timeout jiffies have passed,
|
|
continuation() will be invoked.
|
|
|
|
If nice is 1, the test will done approximately once a
|
|
jiffy. If nice is 0, the test will also be done whenever
|
|
the scheduler runs (by adding it to a task queue). If
|
|
nice is greater than 1, the test will be done once every
|
|
(nice-1) jiffies.
|
|
|
|
*/
|
|
|
|
/* Changes:
|
|
|
|
1.01 1998.05.03 Switched from cli()/sti() to spinlocks
|
|
1.02 1998.12.14 Added support for nice > 1
|
|
*/
|
|
|
|
#define PS_VERSION "1.02"
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/workqueue.h>
|
|
|
|
static void ps_tq_int( void *data);
|
|
|
|
static void (* ps_continuation)(void);
|
|
static int (* ps_ready)(void);
|
|
static unsigned long ps_timeout;
|
|
static int ps_tq_active = 0;
|
|
static int ps_nice = 0;
|
|
|
|
static DEFINE_SPINLOCK(ps_spinlock __attribute__((unused)));
|
|
|
|
static DECLARE_WORK(ps_tq, ps_tq_int, NULL);
|
|
|
|
static void ps_set_intr(void (*continuation)(void),
|
|
int (*ready)(void),
|
|
int timeout, int nice)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ps_spinlock,flags);
|
|
|
|
ps_continuation = continuation;
|
|
ps_ready = ready;
|
|
ps_timeout = jiffies + timeout;
|
|
ps_nice = nice;
|
|
|
|
if (!ps_tq_active) {
|
|
ps_tq_active = 1;
|
|
if (!ps_nice)
|
|
schedule_work(&ps_tq);
|
|
else
|
|
schedule_delayed_work(&ps_tq, ps_nice-1);
|
|
}
|
|
spin_unlock_irqrestore(&ps_spinlock,flags);
|
|
}
|
|
|
|
static void ps_tq_int(void *data)
|
|
{
|
|
void (*con)(void);
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ps_spinlock,flags);
|
|
|
|
con = ps_continuation;
|
|
ps_tq_active = 0;
|
|
|
|
if (!con) {
|
|
spin_unlock_irqrestore(&ps_spinlock,flags);
|
|
return;
|
|
}
|
|
if (!ps_ready || ps_ready() || time_after_eq(jiffies, ps_timeout)) {
|
|
ps_continuation = NULL;
|
|
spin_unlock_irqrestore(&ps_spinlock,flags);
|
|
con();
|
|
return;
|
|
}
|
|
ps_tq_active = 1;
|
|
if (!ps_nice)
|
|
schedule_work(&ps_tq);
|
|
else
|
|
schedule_delayed_work(&ps_tq, ps_nice-1);
|
|
spin_unlock_irqrestore(&ps_spinlock,flags);
|
|
}
|
|
|
|
/* end of pseudo.h */
|
|
|