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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/block/paride/pseudo.h
Initial import
Diffstat (limited to 'drivers/block/paride/pseudo.h')
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diff --git a/drivers/block/paride/pseudo.h b/drivers/block/paride/pseudo.h
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+/*
+ 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(struct work_struct *work);
+
+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_DELAYED_WORK(ps_tq, ps_tq_int);
+
+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_delayed_work(&ps_tq, 0);
+ else
+ schedule_delayed_work(&ps_tq, ps_nice-1);
+ }
+ spin_unlock_irqrestore(&ps_spinlock,flags);
+}
+
+static void ps_tq_int(struct work_struct *work)
+{
+ 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_delayed_work(&ps_tq, 0);
+ else
+ schedule_delayed_work(&ps_tq, ps_nice-1);
+ spin_unlock_irqrestore(&ps_spinlock,flags);
+}
+
+/* end of pseudo.h */
+