[PATCH 7/7] hw/misc/mps2-fpgaio: Implement push-buttons

[Philippe Mathieu-Daudé]

The FPGA system control block has 2 push-buttons labelled PB0/PB1.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 include/hw/misc/mps2-fpgaio.h |  1 +
 hw/misc/mps2-fpgaio.c         | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/include/hw/misc/mps2-fpgaio.h b/include/hw/misc/mps2-fpgaio.h
index 69e265cd4b..521900ae81 100644
--- a/include/hw/misc/mps2-fpgaio.h
+++ b/include/hw/misc/mps2-fpgaio.h
@@ -34,6 +34,7 @@ typedef struct {
     MemoryRegion iomem;
 
     uint32_t led0;
+    uint32_t button;
     uint32_t prescale;
     uint32_t misc;
 
diff --git a/hw/misc/mps2-fpgaio.c b/hw/misc/mps2-fpgaio.c
index 2f3fbeef34..655e7a14fc 100644
--- a/hw/misc/mps2-fpgaio.c
+++ b/hw/misc/mps2-fpgaio.c
@@ -18,6 +18,7 @@
 #include "qemu/osdep.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
+#include "qemu/bitops.h"
 #include "qapi/error.h"
 #include "trace.h"
 #include "hw/sysbus.h"
@@ -36,6 +37,13 @@ REG32(PRESCALE, 0x1c)
 REG32(PSCNTR, 0x20)
 REG32(MISC, 0x4c)
 
+static void mps2_fpgaio_push_button(void *opaque, int irq, int level)
+{
+    MPS2FPGAIO *s = MPS2_FPGAIO(opaque);
+
+    s->button = deposit32(s->button, irq, 1, level);
+}
+
 static uint32_t counter_from_tickoff(int64_t now, int64_t tick_offset, int frq)
 {
     return muldiv64(now - tick_offset, frq, NANOSECONDS_PER_SECOND);
@@ -131,7 +139,7 @@ static uint64_t mps2_fpgaio_read(void *opaque, hwaddr 
offset, unsigned size)
         /* User-pressable board buttons. We don't model that, so just return
          * zeroes.
          */
-        r = 0;
+        r = s->button;
         break;
     case A_PRESCALE:
         r = s->prescale;
@@ -232,6 +240,7 @@ static void mps2_fpgaio_reset(DeviceState *dev)
 
     trace_mps2_fpgaio_reset();
     s->led0 = 0;
+    s->button = 0;
     s->prescale = 0;
     s->misc = 0;
     s->clk1hz_tick_offset = tickoff_from_counter(now, 0, 1);
@@ -249,6 +258,8 @@ static void mps2_fpgaio_init(Object *obj)
     memory_region_init_io(&s->iomem, obj, &mps2_fpgaio_ops, s,
                           "mps2-fpgaio", 0x1000);
     sysbus_init_mmio(sbd, &s->iomem);
+
+    qdev_init_gpio_in_named(DEVICE(s), mps2_fpgaio_push_button, "PB", 2);
 }
 
 static bool mps2_fpgaio_counters_needed(void *opaque)
-- 
2.21.3