xilinx: Add interrupt controller.

Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@gmail.com>

hw/xilinx_intc.c

+/*
+ * QEMU Xilinx OPB Interrupt Controller.
+ *
+ * Copyright (c) 2009 Edgar E. Iglesias.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "sysbus.h"
+#include "hw.h"
+
+#define D(x)
+
+#define R_ISR       0
+#define R_IPR       1
+#define R_IER       2
+#define R_IAR       3
+#define R_SIE       4
+#define R_CIE       5
+#define R_IVR       6
+#define R_MER       7
+#define R_MAX       8
+
+struct xlx_pic
+{
+    SysBusDevice busdev;
+    qemu_irq parent_irq;
+
+    /* Configuration reg chosen at synthesis-time. QEMU populates
+       the bits at board-setup.  */
+    uint32_t c_kind_of_intr;
+
+    /* Runtime control registers.  */
+    uint32_t regs[R_MAX];
+};
+
+static void update_irq(struct xlx_pic *p)
+{
+    uint32_t i;
+    /* Update the pending register.  */
+    p->regs[R_IPR] = p->regs[R_ISR] & p->regs[R_IER];
+
+    /* Update the vector register.  */
+    for (i = 0; i < 32; i++) {
+        if (p->regs[R_IPR] & (1 << i))
+            break;
+    }
+    if (i == 32)
+        i = ~0;
+
+    p->regs[R_IVR] = i;
+    if ((p->regs[R_MER] & 1) && p->regs[R_IPR]) {
+        qemu_irq_raise(p->parent_irq);
+    } else {
+        qemu_irq_lower(p->parent_irq);
+    }
+}
+
+static uint32_t pic_readl (void *opaque, target_phys_addr_t addr)
+{
+    struct xlx_pic *p = opaque;
+    uint32_t r = 0;
+
+    addr >>= 2;
+    switch (addr)
+    {
+        default:
+            if (addr < ARRAY_SIZE(p->regs))
+                r = p->regs[addr];
+            break;
+
+    }
+    D(printf("%s %x=%x\n", __func__, addr * 4, r));
+    return r;
+}
+
+static void
+pic_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
+{
+    struct xlx_pic *p = opaque;
+
+    addr >>= 2;
+    D(qemu_log("%s addr=%x val=%x\n", __func__, addr * 4, value));
+    switch (addr) 
+    {
+        case R_IAR:
+            p->regs[R_ISR] &= ~value; /* ACK.  */
+            break;
+        case R_SIE:
+            p->regs[R_IER] |= value;  /* Atomic set ie.  */
+            break;
+        case R_CIE:
+            p->regs[R_IER] &= ~value; /* Atomic clear ie.  */
+            break;
+        default:
+            if (addr < ARRAY_SIZE(p->regs))
+                p->regs[addr] = value;
+            break;
+    }
+    update_irq(p);
+}
+
+static CPUReadMemoryFunc *pic_read[] = {
+    NULL, NULL,
+    &pic_readl,
+};
+
+static CPUWriteMemoryFunc *pic_write[] = {
+    NULL, NULL,
+    &pic_writel,
+};
+
+static void irq_handler(void *opaque, int irq, int level)
+{
+    struct xlx_pic *p = opaque;
+
+    if (!(p->regs[R_MER] & 2)) {
+        qemu_irq_lower(p->parent_irq);
+        return;
+    }
+
+    /* Update source flops. Don't clear unless level triggered.
+       Edge triggered interrupts only go away when explicitely acked to
+       the interrupt controller.  */
+    if (!(p->c_kind_of_intr & (1 << irq)) || level) {
+        p->regs[R_ISR] &= ~(1 << irq);
+        p->regs[R_ISR] |= (level << irq);
+    }
+    update_irq(p);
+}
+
+static void xilinx_intc_init(SysBusDevice *dev)
+{
+    struct xlx_pic *p = FROM_SYSBUS(typeof (*p), dev);
+    int pic_regs;
+
+    p->c_kind_of_intr = qdev_get_prop_int(&dev->qdev, "kind-of-intr", 0);
+    qdev_init_gpio_in(&dev->qdev, irq_handler, 32);
+    sysbus_init_irq(dev, &p->parent_irq);
+
+    pic_regs = cpu_register_io_memory(0, pic_read, pic_write, p);
+    sysbus_init_mmio(dev, R_MAX * 4, pic_regs);
+}
+
+static void xilinx_intc_register(void)
+{
+    sysbus_register_dev("xilinx,intc", sizeof (struct xlx_pic),
+                        xilinx_intc_init);
+}
+
+device_init(xilinx_intc_register)