[PATCH] sim: gpio: update mask a/b signals better

[Mike Frysinger <vapier at gentoo dot org>]

When the mask a/b MMRs are written, the output signal might change levels
(as pins are [un]masked), so make sure we update the output level.

Further, make sure we handle edge ints correctly by first sending a high
signal followed by a low signal.

Committed.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

2011-04-08  Mike Frysinger  <vapier@gentoo.org>

	* dv-bfin_gpio.c (bfin_gpio): Add "int_state" member.
	(bfin_gpio_forward_int, bfin_gpio_forward_ints): New functions.
	(bfin_gpio_io_write_buffer): Call bfin_gpio_forward_int when the
	mask a or mask b MMRs are written.
	(bfin_gpio_port_event): When handling edge gpios, set the bit in
	int_state, call bfin_gpio_forward_ints, and then clear the bit.
	When handling level gpios, clear/set the bit in int_state rather
	than returning immediately.  Call bfin_gpio_forward_ints instead
	of checking mask[ab] and calling HW_TRACE/hw_port_event directly.
---
 sim/bfin/dv-bfin_gpio.c |   49 +++++++++++++++++++++++++++++++++++-----------
 1 files changed, 37 insertions(+), 12 deletions(-)

diff --git a/sim/bfin/dv-bfin_gpio.c b/sim/bfin/dv-bfin_gpio.c
index 23d2610..7a6acb6 100644
--- a/sim/bfin/dv-bfin_gpio.c
+++ b/sim/bfin/dv-bfin_gpio.c
@@ -28,6 +28,8 @@ struct bfin_gpio
 {
   bu32 base;
 
+  bu16 int_state;
+
   /* Order after here is important -- matches hardware MMR layout.  */
   bu16 BFIN_MMR_16(data);
   bu16 BFIN_MMR_16(clear);
@@ -60,6 +62,20 @@ static const char * const mmr_names[] =
 };
 #define mmr_name(off) mmr_names[(off) / 4]
 
+static void
+bfin_gpio_forward_int (struct hw *me, struct bfin_gpio *port, bu32 mask,
+		       int dst_port)
+{
+  HW_TRACE ((me, "resending levels on port %c", 'a' + dst_port));
+  hw_port_event (me, dst_port, !!(port->int_state & mask));
+}
+static void
+bfin_gpio_forward_ints (struct hw *me, struct bfin_gpio *port)
+{
+  bfin_gpio_forward_int (me, port, port->maska, 0);
+  bfin_gpio_forward_int (me, port, port->maskb, 1);
+}
+
 static unsigned
 bfin_gpio_io_write_buffer (struct hw *me, const void *source, int space,
 			   address_word addr, unsigned nr_bytes)
@@ -115,6 +131,17 @@ bfin_gpio_io_write_buffer (struct hw *me, const void *source, int space,
       break;
     }
 
+  /* If updating masks, make sure we send updated port info.  */
+  switch (mmr_off)
+    {
+    case mmr_offset(maska) ... mmr_offset(maska_toggle):
+      bfin_gpio_forward_int (me, port, port->maska, 0);
+      break;
+    case mmr_offset(maskb) ... mmr_offset(maskb_toggle):
+      bfin_gpio_forward_int (me, port, port->maskb, 1);
+      break;
+    }
+
   return nr_bytes;
 }
 
@@ -250,6 +277,11 @@ bfin_gpio_port_event (struct hw *me, int my_port, struct hw *source,
 	      return;
 	    }
 	}
+
+      /* Send the signal up, and then fall through to clear it.  */
+      port->int_state |= bit;
+      bfin_gpio_forward_ints (me, port);
+      port->int_state &= ~bit;
     }
   else
     {
@@ -258,21 +290,14 @@ bfin_gpio_port_event (struct hw *me, int my_port, struct hw *source,
 	{
 	  HW_TRACE ((me, "ignoring int due to EDGE=%i POLAR=%i lvl=%i",
 		     !!(port->edge & bit), !!(port->polar & bit), nlvl));
-	  return;
+	  /* We still need to signal SIC to clear the int, so don't return.  */
+	  port->int_state &= ~bit;
 	}
+      else
+	port->int_state |= bit;
     }
 
-  /* If the masks allow it, push the interrupt even higher.  */
-  if (port->maska & bit)
-    {
-      HW_TRACE ((me, "pin %i triggered an int via mask a", my_port));
-      hw_port_event (me, 0, 1);
-    }
-  if (port->maskb & bit)
-    {
-      HW_TRACE ((me, "pin %i triggered an int via mask b", my_port));
-      hw_port_event (me, 1, 1);
-    }
+  bfin_gpio_forward_ints (me, port);
 }
 
 static void
-- 
1.7.5.rc1