Archipelago » qemu

/*

 * QEMU model of the Xilinx timer block.

 *

 * 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 "qemu-timer.h"

#define D(x)

#define R_TCSR     0

#define R_TLR      1

#define R_TCR      2

#define R_MAX      4

#define TCSR_MDT        (1<<0)

#define TCSR_UDT        (1<<1)

#define TCSR_GENT       (1<<2)

#define TCSR_CAPT       (1<<3)

#define TCSR_ARHT       (1<<4)

#define TCSR_LOAD       (1<<5)

#define TCSR_ENIT       (1<<6)

#define TCSR_ENT        (1<<7)

#define TCSR_TINT       (1<<8)

#define TCSR_PWMA       (1<<9)

#define TCSR_ENALL      (1<<10)

struct xlx_timer

{

    QEMUBH *bh;

    ptimer_state *ptimer;

    void *parent;

    int nr; /* for debug.  */

    unsigned long timer_div;

    uint32_t regs[R_MAX];

};

struct timerblock

{

    SysBusDevice busdev;

    MemoryRegion mmio;

    qemu_irq irq;

    uint32_t nr_timers;

    uint32_t freq_hz;

    struct xlx_timer *timers;

};

static inline unsigned int timer_from_addr(target_phys_addr_t addr)

{

    /* Timers get a 4x32bit control reg area each.  */

    return addr >> 2;

}

static void timer_update_irq(struct timerblock *t)

{

    unsigned int i, irq = 0;

    uint32_t csr;

    for (i = 0; i < t->nr_timers; i++) {

        csr = t->timers[i].regs[R_TCSR];

        irq |= (csr & TCSR_TINT) && (csr & TCSR_ENIT);

    }

    /* All timers within the same slave share a single IRQ line.  */

    qemu_set_irq(t->irq, !!irq);

}

static uint64_t

timer_read(void *opaque, target_phys_addr_t addr, unsigned int size)

{

    struct timerblock *t = opaque;

    struct xlx_timer *xt;

    uint32_t r = 0;

    unsigned int timer;

    addr >>= 2;

    timer = timer_from_addr(addr);

    xt = &t->timers[timer];

    /* Further decoding to address a specific timers reg.  */

    addr &= 0x3;

    switch (addr)

    {

        case R_TCR:

                r = ptimer_get_count(xt->ptimer);

                if (!(xt->regs[R_TCSR] & TCSR_UDT))

                    r = ~r;

                D(qemu_log("xlx_timer t=%d read counter=%x udt=%d\n",

                         timer, r, xt->regs[R_TCSR] & TCSR_UDT));

            break;

        default:

            if (addr < ARRAY_SIZE(xt->regs))

                r = xt->regs[addr];

            break;

    }

    D(printf("%s timer=%d %x=%x\n", __func__, timer, addr * 4, r));

    return r;

}

static void timer_enable(struct xlx_timer *xt)

{

    uint64_t count;

    D(printf("%s timer=%d down=%d\n", __func__,

              xt->nr, xt->regs[R_TCSR] & TCSR_UDT));

    ptimer_stop(xt->ptimer);

    if (xt->regs[R_TCSR] & TCSR_UDT)

        count = xt->regs[R_TLR];

    else

        count = ~0 - xt->regs[R_TLR];

    ptimer_set_count(xt->ptimer, count);

    ptimer_run(xt->ptimer, 1);

}

static void

timer_write(void *opaque, target_phys_addr_t addr,

            uint64_t val64, unsigned int size)

{

    struct timerblock *t = opaque;

    struct xlx_timer *xt;

    unsigned int timer;

    uint32_t value = val64;

    addr >>= 2;

    timer = timer_from_addr(addr);

    xt = &t->timers[timer];

    D(printf("%s addr=%x val=%x (timer=%d off=%d)\n",

             __func__, addr * 4, value, timer, addr & 3));

    /* Further decoding to address a specific timers reg.  */

    addr &= 3;

    switch (addr) 

    {

        case R_TCSR:

            if (value & TCSR_TINT)

                value &= ~TCSR_TINT;

            xt->regs[addr] = value;

            if (value & TCSR_ENT)

                timer_enable(xt);

            break;

        default:

            if (addr < ARRAY_SIZE(xt->regs))

                xt->regs[addr] = value;

            break;

    }

    timer_update_irq(t);

}

static const MemoryRegionOps timer_ops = {

    .read = timer_read,

    .write = timer_write,

    .endianness = DEVICE_NATIVE_ENDIAN,

    .valid = {

        .min_access_size = 4,

        .max_access_size = 4

    }

};

static void timer_hit(void *opaque)

{

    struct xlx_timer *xt = opaque;

    struct timerblock *t = xt->parent;

    D(printf("%s %d\n", __func__, timer));

    xt->regs[R_TCSR] |= TCSR_TINT;

    if (xt->regs[R_TCSR] & TCSR_ARHT)

        timer_enable(xt);

    timer_update_irq(t);

}

static int xilinx_timer_init(SysBusDevice *dev)

{

    struct timerblock *t = FROM_SYSBUS(typeof (*t), dev);

    unsigned int i;

    /* All timers share a single irq line.  */

    sysbus_init_irq(dev, &t->irq);

    /* Init all the ptimers.  */

    t->timers = g_malloc0(sizeof t->timers[0] * t->nr_timers);

    for (i = 0; i < t->nr_timers; i++) {

        struct xlx_timer *xt = &t->timers[i];

        xt->parent = t;

        xt->nr = i;

        xt->bh = qemu_bh_new(timer_hit, xt);

        xt->ptimer = ptimer_init(xt->bh);

        ptimer_set_freq(xt->ptimer, t->freq_hz);

    }

    memory_region_init_io(&t->mmio, &timer_ops, t, "xilinx-timer",

                          R_MAX * 4 * t->nr_timers);

    sysbus_init_mmio_region(dev, &t->mmio);

    return 0;

}

static SysBusDeviceInfo xilinx_timer_info = {

    .init = xilinx_timer_init,

    .qdev.name  = "xilinx,timer",

    .qdev.size  = sizeof(struct timerblock),

    .qdev.props = (Property[]) {

        DEFINE_PROP_UINT32("frequency", struct timerblock, freq_hz,   0),

        DEFINE_PROP_UINT32("nr-timers", struct timerblock, nr_timers, 0),

        DEFINE_PROP_END_OF_LIST(),

    }

};

static void xilinx_timer_register(void)

{

    sysbus_register_withprop(&xilinx_timer_info);

}

device_init(xilinx_timer_register)