Initial import

1 files changed, 102 insertions, 0 deletions

diff --git a/drivers/block/paride/pseudo.h b/drivers/block/paride/pseudo.h
new file mode 100644
index 000000000..bc3703294
--- /dev/null
+++ 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 */
+