lm32: interrupt controller model

This patch adds the interrupt controller of the lm32. Because the PIC is
accessed through special control registers and opcodes, there are callbacks
from the lm32 translation code to this model.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>

2 files changed, 201 insertions, 0 deletions

diff --git a/hw/lm32_pic.c b/hw/lm32_pic.c
new file mode 100644
index 0000000000..02941a7d0d
--- /dev/null
+++ b/hw/lm32_pic.c
@@ -0,0 +1,190 @@
+/*
+ *  LatticeMico32 CPU interrupt controller logic.
+ *
+ *  Copyright (c) 2010 Michael Walle <michael@walle.cc>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+
+#include "hw.h"
+#include "pc.h"
+#include "monitor.h"
+#include "sysbus.h"
+#include "trace.h"
+#include "lm32_pic.h"
+
+struct LM32PicState {
+    SysBusDevice busdev;
+    qemu_irq parent_irq;
+    uint32_t im;        /* interrupt mask */
+    uint32_t ip;        /* interrupt pending */
+    uint32_t irq_state;
+
+    /* statistics */
+    uint32_t stats_irq_count[32];
+};
+typedef struct LM32PicState LM32PicState;
+
+static LM32PicState *pic;
+void pic_info(Monitor *mon)
+{
+    if (pic == NULL) {
+        return;
+    }
+
+    monitor_printf(mon, "lm32-pic: im=%08x ip=%08x irq_state=%08x\n",
+            pic->im, pic->ip, pic->irq_state);
+}
+
+void irq_info(Monitor *mon)
+{
+    int i;
+    uint32_t count;
+
+    if (pic == NULL) {
+        return;
+    }
+
+    monitor_printf(mon, "IRQ statistics:\n");
+    for (i = 0; i < 32; i++) {
+        count = pic->stats_irq_count[i];
+        if (count > 0) {
+            monitor_printf(mon, "%2d: %u\n", i, count);
+        }
+    }
+}
+
+static void update_irq(LM32PicState *s)
+{
+    s->ip |= s->irq_state;
+
+    if (s->ip & s->im) {
+        trace_lm32_pic_raise_irq();
+        qemu_irq_raise(s->parent_irq);
+    } else {
+        trace_lm32_pic_lower_irq();
+        qemu_irq_lower(s->parent_irq);
+    }
+}
+
+static void irq_handler(void *opaque, int irq, int level)
+{
+    LM32PicState *s = opaque;
+
+    assert(irq < 32);
+    trace_lm32_pic_interrupt(irq, level);
+
+    if (level) {
+        s->irq_state |= (1 << irq);
+        s->stats_irq_count[irq]++;
+    } else {
+        s->irq_state &= ~(1 << irq);
+    }
+
+    update_irq(s);
+}
+
+void lm32_pic_set_im(DeviceState *d, uint32_t im)
+{
+    LM32PicState *s = container_of(d, LM32PicState, busdev.qdev);
+
+    trace_lm32_pic_set_im(im);
+    s->im = im;
+
+    update_irq(s);
+}
+
+void lm32_pic_set_ip(DeviceState *d, uint32_t ip)
+{
+    LM32PicState *s = container_of(d, LM32PicState, busdev.qdev);
+
+    trace_lm32_pic_set_ip(ip);
+
+    /* ack interrupt */
+    s->ip &= ~ip;
+
+    update_irq(s);
+}
+
+uint32_t lm32_pic_get_im(DeviceState *d)
+{
+    LM32PicState *s = container_of(d, LM32PicState, busdev.qdev);
+
+    trace_lm32_pic_get_im(s->im);
+    return s->im;
+}
+
+uint32_t lm32_pic_get_ip(DeviceState *d)
+{
+    LM32PicState *s = container_of(d, LM32PicState, busdev.qdev);
+
+    trace_lm32_pic_get_ip(s->ip);
+    return s->ip;
+}
+
+static void pic_reset(DeviceState *d)
+{
+    LM32PicState *s = container_of(d, LM32PicState, busdev.qdev);
+    int i;
+
+    s->im = 0;
+    s->ip = 0;
+    s->irq_state = 0;
+    for (i = 0; i < 32; i++) {
+        s->stats_irq_count[i] = 0;
+    }
+}
+
+static int lm32_pic_init(SysBusDevice *dev)
+{
+    LM32PicState *s = FROM_SYSBUS(typeof(*s), dev);
+
+    qdev_init_gpio_in(&dev->qdev, irq_handler, 32);
+    sysbus_init_irq(dev, &s->parent_irq);
+
+    pic = s;
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_lm32_pic = {
+    .name = "lm32-pic",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields      = (VMStateField[]) {
+        VMSTATE_UINT32(im, LM32PicState),
+        VMSTATE_UINT32(ip, LM32PicState),
+        VMSTATE_UINT32(irq_state, LM32PicState),
+        VMSTATE_UINT32_ARRAY(stats_irq_count, LM32PicState, 32),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static SysBusDeviceInfo lm32_pic_info = {
+    .init = lm32_pic_init,
+    .qdev.name  = "lm32-pic",
+    .qdev.size  = sizeof(LM32PicState),
+    .qdev.vmsd  = &vmstate_lm32_pic,
+    .qdev.reset = pic_reset,
+};
+
+static void lm32_pic_register(void)
+{
+    sysbus_register_withprop(&lm32_pic_info);
+}
+
+device_init(lm32_pic_register)
diff --git a/hw/lm32_pic.h b/hw/lm32_pic.h
new file mode 100644
index 0000000000..e6479b8f63
--- /dev/null
+++ b/hw/lm32_pic.h
@@ -0,0 +1,11 @@
+#ifndef QEMU_HW_LM32_PIC_H
+#define QEMU_HW_LM32_PIC_H
+
+#include "qemu-common.h"
+
+uint32_t lm32_pic_get_ip(DeviceState *d);
+uint32_t lm32_pic_get_im(DeviceState *d);
+void lm32_pic_set_ip(DeviceState *d, uint32_t ip);
+void lm32_pic_set_im(DeviceState *d, uint32_t im);
+
+#endif /* QEMU_HW_LM32_PIC_H */