qemu/hw/xilinx_intc.c

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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 *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)