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/*

 * 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 * const pic_read[] = {

    NULL, NULL,

    &pic_readl,

};

static CPUWriteMemoryFunc * const 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 int xilinx_intc_init(SysBusDevice *dev)

{

    struct xlx_pic *p = FROM_SYSBUS(typeof (*p), dev);

    int pic_regs;

    qdev_init_gpio_in(&dev->qdev, irq_handler, 32);

    sysbus_init_irq(dev, &p->parent_irq);

    pic_regs = cpu_register_io_memory(pic_read, pic_write, p);

    sysbus_init_mmio(dev, R_MAX * 4, pic_regs);

    return 0;

}

static SysBusDeviceInfo xilinx_intc_info = {

    .init = xilinx_intc_init,

    .qdev.name  = "xilinx,intc",

    .qdev.size  = sizeof(struct xlx_pic),

    .qdev.props = (Property[]) {

        DEFINE_PROP_UINT32("kind-of-intr", struct xlx_pic, c_kind_of_intr, 0),

        DEFINE_PROP_END_OF_LIST(),

    }

};

static void xilinx_intc_register(void)

{

    sysbus_register_withprop(&xilinx_intc_info);

}

device_init(xilinx_intc_register)