nios2: Add IIC interrupt controller emulation

Add the Altera Nios2 internal interrupt controller model.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chris Wulff <crwulff@gmail.com>
Cc: Jeff Da Silva <jdasilva@altera.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Sandra Loosemore <sandra@codesourcery.com>
Cc: Yves Vandervennet <yvanderv@altera.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Message-Id: <20170118220146.489-5-marex@denx.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>

hw/intc/Makefile.objs

@@ -41,3 +41,4 @@ obj-$(CONFIG_S390_FLIC_KVM) += s390_flic_kvm.o
 obj-$(CONFIG_ASPEED_SOC) += aspeed_vic.o
 obj-$(CONFIG_ARM_GIC) += arm_gicv3_cpuif.o
 obj-$(CONFIG_MIPS_CPS) += mips_gic.o
+obj-$(CONFIG_NIOS2) += nios2_iic.o

hw/intc/nios2_iic.c

+/*
+ * QEMU Altera Internal Interrupt Controller.
+ *
+ * Copyright (c) 2012 Chris Wulff <crwulff@gmail.com>
+ *
+ * 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 2.1 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/lgpl-2.1.html>
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "qapi/error.h"
+
+#include "hw/sysbus.h"
+#include "cpu.h"
+
+#define TYPE_ALTERA_IIC "altera,iic"
+#define ALTERA_IIC(obj) \
+    OBJECT_CHECK(AlteraIIC, (obj), TYPE_ALTERA_IIC)
+
+typedef struct AlteraIIC {
+    SysBusDevice  parent_obj;
+    void         *cpu;
+    qemu_irq      parent_irq;
+} AlteraIIC;
+
+static void update_irq(AlteraIIC *pv)
+{
+    CPUNios2State *env = &((Nios2CPU *)(pv->cpu))->env;
+
+    qemu_set_irq(pv->parent_irq,
+                 env->regs[CR_IPENDING] & env->regs[CR_IENABLE]);
+}
+
+static void irq_handler(void *opaque, int irq, int level)
+{
+    AlteraIIC *pv = opaque;
+    CPUNios2State *env = &((Nios2CPU *)(pv->cpu))->env;
+
+    env->regs[CR_IPENDING] &= ~(1 << irq);
+    env->regs[CR_IPENDING] |= !!level << irq;
+
+    update_irq(pv);
+}
+
+static void altera_iic_init(Object *obj)
+{
+    AlteraIIC *pv = ALTERA_IIC(obj);
+
+    qdev_init_gpio_in(DEVICE(pv), irq_handler, 32);
+    sysbus_init_irq(SYS_BUS_DEVICE(obj), &pv->parent_irq);
+}
+
+static Property altera_iic_properties[] = {
+    DEFINE_PROP_PTR("cpu", AlteraIIC, cpu),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void altera_iic_realize(DeviceState *dev, Error **errp)
+{
+    struct AlteraIIC *pv = ALTERA_IIC(dev);
+
+    if (!pv->cpu) {
+        error_setg(errp, "altera,iic: CPU not connected");
+        return;
+    }
+}
+
+static void altera_iic_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->props = altera_iic_properties;
+    /* Reason: pointer property "cpu" */
+    dc->cannot_instantiate_with_device_add_yet = true;
+    dc->realize = altera_iic_realize;
+}
+
+static TypeInfo altera_iic_info = {
+    .name          = "altera,iic",
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(AlteraIIC),
+    .instance_init = altera_iic_init,
+    .class_init    = altera_iic_class_init,
+};
+
+static void altera_iic_register(void)
+{
+    type_register_static(&altera_iic_info);
+}
+
+type_init(altera_iic_register)