1 files changed, 123 insertions, 0 deletions
diff --git a/linux/dev/drivers/net/auto_irq.c b/linux/dev/drivers/net/auto_irq.c
new file mode 100644
index 00000000..73cfe346
--- /dev/null
+++ b/linux/dev/drivers/net/auto_irq.c
@@ -0,0 +1,123 @@
+/* auto_irq.c: Auto-configure IRQ lines for linux. */
+/*
+   Written 1994 by Donald Becker.
+
+   The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O
+   Center of Excellence in Space Data and Information Sciences
+   Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771
+
+   This code is a general-purpose IRQ line detector for devices with
+   jumpered IRQ lines.  If you can make the device raise an IRQ (and
+   that IRQ line isn't already being used), these routines will tell
+   you what IRQ line it's using -- perfect for those oh-so-cool boot-time
+   device probes!
+
+   To use this, first call autoirq_setup(timeout). TIMEOUT is how many
+   'jiffies' (1/100 sec.) to detect other devices that have active IRQ lines,
+   and can usually be zero at boot.  'autoirq_setup()' returns the bit
+   vector of nominally-available IRQ lines (lines may be physically in-use,
+   but not yet registered to a device).
+   Next, set up your device to trigger an interrupt.
+   Finally call autoirq_report(TIMEOUT) to find out which IRQ line was
+   most recently active.  The TIMEOUT should usually be zero, but may
+   be set to the number of jiffies to wait for a slow device to raise an IRQ.
+
+   The idea of using the setup timeout to filter out bogus IRQs came from
+   the serial driver.
+ */
+
+
+#ifdef version
+static const char *version =
+"auto_irq.c:v1.11 Donald Becker (becker@cesdis.gsfc.nasa.gov)";
+#endif
+
+#include <sys/types.h>
+#include <mach/mach_types.h>
+#include <mach/vm_param.h>
+
+#define MACH_INCLUDE
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <asm/bitops.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <linux/netdevice.h>
+
+void *irq2dev_map[NR_IRQS] = {0, 0, /* ... zeroed */ };
+
+unsigned long irqs_busy = 0x2147;	/* The set of fixed IRQs (keyboard, timer, etc) */
+unsigned long irqs_used = 0x0001;	/* The set of fixed IRQs sometimes enabled. */
+unsigned long irqs_reserved = 0x0000;	/* An advisory "reserved" table. */
+unsigned long irqs_shared = 0x0000;	/* IRQ lines "shared" among conforming cards. */
+
+static volatile unsigned long irq_bitmap;	/* The irqs we actually found. */
+static unsigned long irq_handled;	/* The irq lines we have a handler on. */
+static volatile int irq_number;	/* The latest irq number we actually found. */
+
+static void 
+autoirq_probe (int irq, void *dev_id, struct pt_regs *regs)
+{
+  irq_number = irq;
+  set_bit (irq, (void *) &irq_bitmap);	/* irq_bitmap |= 1 << irq; */
+  /* This code used to disable the irq. However, the interrupt stub
+   * would then re-enable the interrupt with (potentially) disastrous
+   * consequences
+   */
+  free_irq (irq, dev_id);
+  return;
+}
+
+int 
+autoirq_setup (int waittime)
+{
+  int i;
+  unsigned long timeout = jiffies + waittime;
+  unsigned long boguscount = (waittime * loops_per_sec) / 100;
+
+  irq_handled = 0;
+  irq_bitmap = 0;
+
+  for (i = 0; i < 16; i++)
+    {
+      if (test_bit (i, &irqs_busy) == 0
+	  && request_irq (i, autoirq_probe, SA_INTERRUPT, "irq probe", NULL) == 0)
+	set_bit (i, (void *) &irq_handled);	/* irq_handled |= 1 << i; */
+    }
+  /* Update our USED lists. */
+  irqs_used |= ~irq_handled;
+
+  /* Hang out at least <waittime> jiffies waiting for bogus IRQ hits. */
+  while (timeout > jiffies && --boguscount > 0)
+    ;
+
+  irq_handled &= ~irq_bitmap;
+
+  irq_number = 0;		/* We are interested in new interrupts from now on */
+
+  return irq_handled;
+}
+
+int 
+autoirq_report (int waittime)
+{
+  int i;
+  unsigned long timeout = jiffies + waittime;
+  unsigned long boguscount = (waittime * loops_per_sec) / 100;
+
+  /* Hang out at least <waittime> jiffies waiting for the IRQ. */
+
+  while (timeout > jiffies && --boguscount > 0)
+    if (irq_number)
+      break;
+
+  irq_handled &= ~irq_bitmap;	/* This eliminates the already reset handlers */
+
+  /* Retract the irq handlers that we installed. */
+  for (i = 0; i < 16; i++)
+    {
+      if (test_bit (i, (void *) &irq_handled))
+	free_irq (i, NULL);
+    }
+  return irq_number;
+}