Archipelago » qemu

/*

 *  QEMU model of the Milkymist System Controller.

 *

 *  Copyright (c) 2010-2012 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/>.

 *

 *

 * Specification available at:

 *   http://www.milkymist.org/socdoc/sysctl.pdf

 */

#include "hw/hw.h"

#include "hw/sysbus.h"

#include "sysemu/sysemu.h"

#include "trace.h"

#include "qemu/timer.h"

#include "hw/ptimer.h"

#include "qemu/error-report.h"

enum {

    CTRL_ENABLE      = (1<<0),

    CTRL_AUTORESTART = (1<<1),

};

enum {

    ICAP_READY       = (1<<0),

};

enum {

    R_GPIO_IN         = 0,

    R_GPIO_OUT,

    R_GPIO_INTEN,

    R_TIMER0_CONTROL  = 4,

    R_TIMER0_COMPARE,

    R_TIMER0_COUNTER,

    R_TIMER1_CONTROL  = 8,

    R_TIMER1_COMPARE,

    R_TIMER1_COUNTER,

    R_ICAP = 16,

    R_DBG_SCRATCHPAD  = 20,

    R_DBG_WRITE_LOCK,

    R_CLK_FREQUENCY   = 29,

    R_CAPABILITIES,

    R_SYSTEM_ID,

    R_MAX

};

struct MilkymistSysctlState {

    SysBusDevice busdev;

    MemoryRegion regs_region;

    QEMUBH *bh0;

    QEMUBH *bh1;

    ptimer_state *ptimer0;

    ptimer_state *ptimer1;

    uint32_t freq_hz;

    uint32_t capabilities;

    uint32_t systemid;

    uint32_t strappings;

    uint32_t regs[R_MAX];

    qemu_irq gpio_irq;

    qemu_irq timer0_irq;

    qemu_irq timer1_irq;

};

typedef struct MilkymistSysctlState MilkymistSysctlState;

static void sysctl_icap_write(MilkymistSysctlState *s, uint32_t value)

{

    trace_milkymist_sysctl_icap_write(value);

    switch (value & 0xffff) {

    case 0x000e:

        qemu_system_shutdown_request();

        break;

    }

}

static uint64_t sysctl_read(void *opaque, hwaddr addr,

                            unsigned size)

{

    MilkymistSysctlState *s = opaque;

    uint32_t r = 0;

    addr >>= 2;

    switch (addr) {

    case R_TIMER0_COUNTER:

        r = (uint32_t)ptimer_get_count(s->ptimer0);

        /* milkymist timer counts up */

        r = s->regs[R_TIMER0_COMPARE] - r;

        break;

    case R_TIMER1_COUNTER:

        r = (uint32_t)ptimer_get_count(s->ptimer1);

        /* milkymist timer counts up */

        r = s->regs[R_TIMER1_COMPARE] - r;

        break;

    case R_GPIO_IN:

    case R_GPIO_OUT:

    case R_GPIO_INTEN:

    case R_TIMER0_CONTROL:

    case R_TIMER0_COMPARE:

    case R_TIMER1_CONTROL:

    case R_TIMER1_COMPARE:

    case R_ICAP:

    case R_DBG_SCRATCHPAD:

    case R_DBG_WRITE_LOCK:

    case R_CLK_FREQUENCY:

    case R_CAPABILITIES:

    case R_SYSTEM_ID:

        r = s->regs[addr];

        break;

    default:

        error_report("milkymist_sysctl: read access to unknown register 0x"

                TARGET_FMT_plx, addr << 2);

        break;

    }

    trace_milkymist_sysctl_memory_read(addr << 2, r);

    return r;

}

static void sysctl_write(void *opaque, hwaddr addr, uint64_t value,

                         unsigned size)

{

    MilkymistSysctlState *s = opaque;

    trace_milkymist_sysctl_memory_write(addr, value);

    addr >>= 2;

    switch (addr) {

    case R_GPIO_OUT:

    case R_GPIO_INTEN:

    case R_TIMER0_COUNTER:

    case R_TIMER1_COUNTER:

    case R_DBG_SCRATCHPAD:

        s->regs[addr] = value;

        break;

    case R_TIMER0_COMPARE:

        ptimer_set_limit(s->ptimer0, value, 0);

        s->regs[addr] = value;

        break;

    case R_TIMER1_COMPARE:

        ptimer_set_limit(s->ptimer1, value, 0);

        s->regs[addr] = value;

        break;

    case R_TIMER0_CONTROL:

        s->regs[addr] = value;

        if (s->regs[R_TIMER0_CONTROL] & CTRL_ENABLE) {

            trace_milkymist_sysctl_start_timer0();

            ptimer_set_count(s->ptimer0,

                    s->regs[R_TIMER0_COMPARE] - s->regs[R_TIMER0_COUNTER]);

            ptimer_run(s->ptimer0, 0);

        } else {

            trace_milkymist_sysctl_stop_timer0();

            ptimer_stop(s->ptimer0);

        }

        break;

    case R_TIMER1_CONTROL:

        s->regs[addr] = value;

        if (s->regs[R_TIMER1_CONTROL] & CTRL_ENABLE) {

            trace_milkymist_sysctl_start_timer1();

            ptimer_set_count(s->ptimer1,

                    s->regs[R_TIMER1_COMPARE] - s->regs[R_TIMER1_COUNTER]);

            ptimer_run(s->ptimer1, 0);

        } else {

            trace_milkymist_sysctl_stop_timer1();

            ptimer_stop(s->ptimer1);

        }

        break;

    case R_ICAP:

        sysctl_icap_write(s, value);

        break;

    case R_DBG_WRITE_LOCK:

        s->regs[addr] = 1;

        break;

    case R_SYSTEM_ID:

        qemu_system_reset_request();

        break;

    case R_GPIO_IN:

    case R_CLK_FREQUENCY:

    case R_CAPABILITIES:

        error_report("milkymist_sysctl: write to read-only register 0x"

                TARGET_FMT_plx, addr << 2);

        break;

    default:

        error_report("milkymist_sysctl: write access to unknown register 0x"

                TARGET_FMT_plx, addr << 2);

        break;

    }

}

static const MemoryRegionOps sysctl_mmio_ops = {

    .read = sysctl_read,

    .write = sysctl_write,

    .valid = {

        .min_access_size = 4,

        .max_access_size = 4,

    },

    .endianness = DEVICE_NATIVE_ENDIAN,

};

static void timer0_hit(void *opaque)

{

    MilkymistSysctlState *s = opaque;

    if (!(s->regs[R_TIMER0_CONTROL] & CTRL_AUTORESTART)) {

        s->regs[R_TIMER0_CONTROL] &= ~CTRL_ENABLE;

        trace_milkymist_sysctl_stop_timer0();

        ptimer_stop(s->ptimer0);

    }

    trace_milkymist_sysctl_pulse_irq_timer0();

    qemu_irq_pulse(s->timer0_irq);

}

static void timer1_hit(void *opaque)

{

    MilkymistSysctlState *s = opaque;

    if (!(s->regs[R_TIMER1_CONTROL] & CTRL_AUTORESTART)) {

        s->regs[R_TIMER1_CONTROL] &= ~CTRL_ENABLE;

        trace_milkymist_sysctl_stop_timer1();

        ptimer_stop(s->ptimer1);

    }

    trace_milkymist_sysctl_pulse_irq_timer1();

    qemu_irq_pulse(s->timer1_irq);

}

static void milkymist_sysctl_reset(DeviceState *d)

{

    MilkymistSysctlState *s =

            container_of(d, MilkymistSysctlState, busdev.qdev);

    int i;

    for (i = 0; i < R_MAX; i++) {

        s->regs[i] = 0;

    }

    ptimer_stop(s->ptimer0);

    ptimer_stop(s->ptimer1);

    /* defaults */

    s->regs[R_ICAP] = ICAP_READY;

    s->regs[R_SYSTEM_ID] = s->systemid;

    s->regs[R_CLK_FREQUENCY] = s->freq_hz;

    s->regs[R_CAPABILITIES] = s->capabilities;

    s->regs[R_GPIO_IN] = s->strappings;

}

static int milkymist_sysctl_init(SysBusDevice *dev)

{

    MilkymistSysctlState *s = FROM_SYSBUS(typeof(*s), dev);

    sysbus_init_irq(dev, &s->gpio_irq);

    sysbus_init_irq(dev, &s->timer0_irq);

    sysbus_init_irq(dev, &s->timer1_irq);

    s->bh0 = qemu_bh_new(timer0_hit, s);

    s->bh1 = qemu_bh_new(timer1_hit, s);

    s->ptimer0 = ptimer_init(s->bh0);

    s->ptimer1 = ptimer_init(s->bh1);

    ptimer_set_freq(s->ptimer0, s->freq_hz);

    ptimer_set_freq(s->ptimer1, s->freq_hz);

    memory_region_init_io(&s->regs_region, &sysctl_mmio_ops, s,

            "milkymist-sysctl", R_MAX * 4);

    sysbus_init_mmio(dev, &s->regs_region);

    return 0;

}

static const VMStateDescription vmstate_milkymist_sysctl = {

    .name = "milkymist-sysctl",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields      = (VMStateField[]) {

        VMSTATE_UINT32_ARRAY(regs, MilkymistSysctlState, R_MAX),

        VMSTATE_PTIMER(ptimer0, MilkymistSysctlState),

        VMSTATE_PTIMER(ptimer1, MilkymistSysctlState),

        VMSTATE_END_OF_LIST()

    }

};

static Property milkymist_sysctl_properties[] = {

    DEFINE_PROP_UINT32("frequency", MilkymistSysctlState,

    freq_hz, 80000000),

    DEFINE_PROP_UINT32("capabilities", MilkymistSysctlState,

    capabilities, 0x00000000),

    DEFINE_PROP_UINT32("systemid", MilkymistSysctlState,

    systemid, 0x10014d31),

    DEFINE_PROP_UINT32("gpio_strappings", MilkymistSysctlState,

    strappings, 0x00000001),

    DEFINE_PROP_END_OF_LIST(),

};

static void milkymist_sysctl_class_init(ObjectClass *klass, void *data)

{

    DeviceClass *dc = DEVICE_CLASS(klass);

    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);

    k->init = milkymist_sysctl_init;

    dc->reset = milkymist_sysctl_reset;

    dc->vmsd = &vmstate_milkymist_sysctl;

    dc->props = milkymist_sysctl_properties;

}

static const TypeInfo milkymist_sysctl_info = {

    .name          = "milkymist-sysctl",

    .parent        = TYPE_SYS_BUS_DEVICE,

    .instance_size = sizeof(MilkymistSysctlState),

    .class_init    = milkymist_sysctl_class_init,

};

static void milkymist_sysctl_register_types(void)

{

    type_register_static(&milkymist_sysctl_info);

}

type_init(milkymist_sysctl_register_types)