Archipelago » qemu

/*

 * QEMU ETRAX Timers

 *

 * Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.

 *

 * 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 "sysemu.h"

#include "qemu-timer.h"

#define D(x)

#define RW_TMR0_DIV   0x00

#define R_TMR0_DATA   0x04

#define RW_TMR0_CTRL  0x08

#define RW_TMR1_DIV   0x10

#define R_TMR1_DATA   0x14

#define RW_TMR1_CTRL  0x18

#define R_TIME        0x38

#define RW_WD_CTRL    0x40

#define R_WD_STAT     0x44

#define RW_INTR_MASK  0x48

#define RW_ACK_INTR   0x4c

#define R_INTR        0x50

#define R_MASKED_INTR 0x54

struct etrax_timer {

    SysBusDevice busdev;

    MemoryRegion mmio;

    qemu_irq irq;

    qemu_irq nmi;

    QEMUBH *bh_t0;

    QEMUBH *bh_t1;

    QEMUBH *bh_wd;

    ptimer_state *ptimer_t0;

    ptimer_state *ptimer_t1;

    ptimer_state *ptimer_wd;

    int wd_hits;

    /* Control registers.  */

    uint32_t rw_tmr0_div;

    uint32_t r_tmr0_data;

    uint32_t rw_tmr0_ctrl;

    uint32_t rw_tmr1_div;

    uint32_t r_tmr1_data;

    uint32_t rw_tmr1_ctrl;

    uint32_t rw_wd_ctrl;

    uint32_t rw_intr_mask;

    uint32_t rw_ack_intr;

    uint32_t r_intr;

    uint32_t r_masked_intr;

};

static uint64_t

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

{

    struct etrax_timer *t = opaque;

    uint32_t r = 0;

    switch (addr) {

    case R_TMR0_DATA:

        r = ptimer_get_count(t->ptimer_t0);

        break;

    case R_TMR1_DATA:

        r = ptimer_get_count(t->ptimer_t1);

        break;

    case R_TIME:

        r = qemu_get_clock_ns(vm_clock) / 10;

        break;

    case RW_INTR_MASK:

        r = t->rw_intr_mask;

        break;

    case R_MASKED_INTR:

        r = t->r_intr & t->rw_intr_mask;

        break;

    default:

        D(printf ("%s %x\n", __func__, addr));

        break;

    }

    return r;

}

static void update_ctrl(struct etrax_timer *t, int tnum)

{

    unsigned int op;

    unsigned int freq;

    unsigned int freq_hz;

    unsigned int div;

    uint32_t ctrl;

    ptimer_state *timer;

    if (tnum == 0) {

        ctrl = t->rw_tmr0_ctrl;

        div = t->rw_tmr0_div;

        timer = t->ptimer_t0;

    } else {

        ctrl = t->rw_tmr1_ctrl;

        div = t->rw_tmr1_div;

        timer = t->ptimer_t1;

    }

    op = ctrl & 3;

    freq = ctrl >> 2;

    freq_hz = 32000000;

    switch (freq)

    {

    case 0:

    case 1:

        D(printf ("extern or disabled timer clock?\n"));

        break;

    case 4: freq_hz =  29493000; break;

    case 5: freq_hz =  32000000; break;

    case 6: freq_hz =  32768000; break;

    case 7: freq_hz = 100000000; break;

    default:

        abort();

        break;

    }

    D(printf ("freq_hz=%d div=%d\n", freq_hz, div));

    ptimer_set_freq(timer, freq_hz);

    ptimer_set_limit(timer, div, 0);

    switch (op)

    {

        case 0:

            /* Load.  */

            ptimer_set_limit(timer, div, 1);

            break;

        case 1:

            /* Hold.  */

            ptimer_stop(timer);

            break;

        case 2:

            /* Run.  */

            ptimer_run(timer, 0);

            break;

        default:

            abort();

            break;

    }

}

static void timer_update_irq(struct etrax_timer *t)

{

    t->r_intr &= ~(t->rw_ack_intr);

    t->r_masked_intr = t->r_intr & t->rw_intr_mask;

    D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));

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

}

static void timer0_hit(void *opaque)

{

    struct etrax_timer *t = opaque;

    t->r_intr |= 1;

    timer_update_irq(t);

}

static void timer1_hit(void *opaque)

{

    struct etrax_timer *t = opaque;

    t->r_intr |= 2;

    timer_update_irq(t);

}

static void watchdog_hit(void *opaque)

{

    struct etrax_timer *t = opaque;

    if (t->wd_hits == 0) {

        /* real hw gives a single tick before reseting but we are

           a bit friendlier to compensate for our slower execution.  */

        ptimer_set_count(t->ptimer_wd, 10);

        ptimer_run(t->ptimer_wd, 1);

        qemu_irq_raise(t->nmi);

    }

    else

        qemu_system_reset_request();

    t->wd_hits++;

}

static inline void timer_watchdog_update(struct etrax_timer *t, uint32_t value)

{

    unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);

    unsigned int wd_key = t->rw_wd_ctrl >> 9;

    unsigned int wd_cnt = t->rw_wd_ctrl & 511;

    unsigned int new_key = value >> 9 & ((1 << 7) - 1);

    unsigned int new_cmd = (value >> 8) & 1;

    /* If the watchdog is enabled, they written key must match the

       complement of the previous.  */

    wd_key = ~wd_key & ((1 << 7) - 1);

    if (wd_en && wd_key != new_key)

        return;

    D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n", 

         wd_en, new_key, wd_key, new_cmd, wd_cnt));

    if (t->wd_hits)

        qemu_irq_lower(t->nmi);

    t->wd_hits = 0;

    ptimer_set_freq(t->ptimer_wd, 760);

    if (wd_cnt == 0)

        wd_cnt = 256;

    ptimer_set_count(t->ptimer_wd, wd_cnt);

    if (new_cmd)

        ptimer_run(t->ptimer_wd, 1);

    else

        ptimer_stop(t->ptimer_wd);

    t->rw_wd_ctrl = value;

}

static void

timer_write(void *opaque, target_phys_addr_t addr,

            uint64_t val64, unsigned int size)

{

    struct etrax_timer *t = opaque;

    uint32_t value = val64;

    switch (addr)

    {

        case RW_TMR0_DIV:

            t->rw_tmr0_div = value;

            break;

        case RW_TMR0_CTRL:

            D(printf ("RW_TMR0_CTRL=%x\n", value));

            t->rw_tmr0_ctrl = value;

            update_ctrl(t, 0);

            break;

        case RW_TMR1_DIV:

            t->rw_tmr1_div = value;

            break;

        case RW_TMR1_CTRL:

            D(printf ("RW_TMR1_CTRL=%x\n", value));

            t->rw_tmr1_ctrl = value;

            update_ctrl(t, 1);

            break;

        case RW_INTR_MASK:

            D(printf ("RW_INTR_MASK=%x\n", value));

            t->rw_intr_mask = value;

            timer_update_irq(t);

            break;

        case RW_WD_CTRL:

            timer_watchdog_update(t, value);

            break;

        case RW_ACK_INTR:

            t->rw_ack_intr = value;

            timer_update_irq(t);

            t->rw_ack_intr = 0;

            break;

        default:

            printf ("%s " TARGET_FMT_plx " %x\n",

                __func__, addr, value);

            break;

    }

}

static const MemoryRegionOps timer_ops = {

    .read = timer_read,

    .write = timer_write,

    .endianness = DEVICE_LITTLE_ENDIAN,

    .valid = {

        .min_access_size = 4,

        .max_access_size = 4

    }

};

static void etraxfs_timer_reset(void *opaque)

{

    struct etrax_timer *t = opaque;

    ptimer_stop(t->ptimer_t0);

    ptimer_stop(t->ptimer_t1);

    ptimer_stop(t->ptimer_wd);

    t->rw_wd_ctrl = 0;

    t->r_intr = 0;

    t->rw_intr_mask = 0;

    qemu_irq_lower(t->irq);

}

static int etraxfs_timer_init(SysBusDevice *dev)

{

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

    t->bh_t0 = qemu_bh_new(timer0_hit, t);

    t->bh_t1 = qemu_bh_new(timer1_hit, t);

    t->bh_wd = qemu_bh_new(watchdog_hit, t);

    t->ptimer_t0 = ptimer_init(t->bh_t0);

    t->ptimer_t1 = ptimer_init(t->bh_t1);

    t->ptimer_wd = ptimer_init(t->bh_wd);

    sysbus_init_irq(dev, &t->irq);

    sysbus_init_irq(dev, &t->nmi);

    memory_region_init_io(&t->mmio, &timer_ops, t, "etraxfs-timer", 0x5c);

    sysbus_init_mmio_region(dev, &t->mmio);

    qemu_register_reset(etraxfs_timer_reset, t);

    return 0;

}

static void etraxfs_timer_register(void)

{

    sysbus_register_dev("etraxfs,timer", sizeof (struct etrax_timer),

                        etraxfs_timer_init);

}

device_init(etraxfs_timer_register)