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/*

 * Samsung exynos4210 Pulse Width Modulation Timer

 *

 * Copyright (c) 2000 - 2011 Samsung Electronics Co., Ltd.

 * All rights reserved.

 *

 * Evgeny Voevodin <e.voevodin@samsung.com>

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the

 * Free Software Foundation; either version 2 of the License, or (at your

 * option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, see <http://www.gnu.org/licenses/>.

 */

#include "hw/sysbus.h"

#include "qemu/timer.h"

#include "qemu-common.h"

#include "hw/ptimer.h"

#include "hw/arm/exynos4210.h"

//#define DEBUG_PWM

#ifdef DEBUG_PWM

#define DPRINTF(fmt, ...) \

        do { fprintf(stdout, "PWM: [%24s:%5d] " fmt, __func__, __LINE__, \

                ## __VA_ARGS__); } while (0)

#else

#define DPRINTF(fmt, ...) do {} while (0)

#endif

#define     EXYNOS4210_PWM_TIMERS_NUM      5

#define     EXYNOS4210_PWM_REG_MEM_SIZE    0x50

#define     TCFG0        0x0000

#define     TCFG1        0x0004

#define     TCON         0x0008

#define     TCNTB0       0x000C

#define     TCMPB0       0x0010

#define     TCNTO0       0x0014

#define     TCNTB1       0x0018

#define     TCMPB1       0x001C

#define     TCNTO1       0x0020

#define     TCNTB2       0x0024

#define     TCMPB2       0x0028

#define     TCNTO2       0x002C

#define     TCNTB3       0x0030

#define     TCMPB3       0x0034

#define     TCNTO3       0x0038

#define     TCNTB4       0x003C

#define     TCNTO4       0x0040

#define     TINT_CSTAT   0x0044

#define     TCNTB(x)    (0xC * (x))

#define     TCMPB(x)    (0xC * (x) + 1)

#define     TCNTO(x)    (0xC * (x) + 2)

#define GET_PRESCALER(reg, x) (((reg) & (0xFF << (8 * (x)))) >> 8 * (x))

#define GET_DIVIDER(reg, x) (1 << (((reg) & (0xF << (4 * (x)))) >> (4 * (x))))

/*

 * Attention! Timer4 doesn't have OUTPUT_INVERTER,

 * so Auto Reload bit is not accessible by macros!

 */

#define     TCON_TIMER_BASE(x)          (((x) ? 1 : 0) * 4 + 4 * (x))

#define     TCON_TIMER_START(x)         (1 << (TCON_TIMER_BASE(x) + 0))

#define     TCON_TIMER_MANUAL_UPD(x)    (1 << (TCON_TIMER_BASE(x) + 1))

#define     TCON_TIMER_OUTPUT_INV(x)    (1 << (TCON_TIMER_BASE(x) + 2))

#define     TCON_TIMER_AUTO_RELOAD(x)   (1 << (TCON_TIMER_BASE(x) + 3))

#define     TCON_TIMER4_AUTO_RELOAD     (1 << 22)

#define     TINT_CSTAT_STATUS(x)        (1 << (5 + (x)))

#define     TINT_CSTAT_ENABLE(x)        (1 << (x))

/* timer struct */

typedef struct {

    uint32_t    id;             /* timer id */

    qemu_irq    irq;            /* local timer irq */

    uint32_t    freq;           /* timer frequency */

    /* use ptimer.c to represent count down timer */

    ptimer_state *ptimer;       /* timer  */

    /* registers */

    uint32_t    reg_tcntb;      /* counter register buffer */

    uint32_t    reg_tcmpb;      /* compare register buffer */

    struct Exynos4210PWMState *parent;

} Exynos4210PWM;

#define TYPE_EXYNOS4210_PWM "exynos4210.pwm"

#define EXYNOS4210_PWM(obj) \

    OBJECT_CHECK(Exynos4210PWMState, (obj), TYPE_EXYNOS4210_PWM)

typedef struct Exynos4210PWMState {

    SysBusDevice parent_obj;

    MemoryRegion iomem;

    uint32_t    reg_tcfg[2];

    uint32_t    reg_tcon;

    uint32_t    reg_tint_cstat;

    Exynos4210PWM timer[EXYNOS4210_PWM_TIMERS_NUM];

} Exynos4210PWMState;

/*** VMState ***/

static const VMStateDescription vmstate_exynos4210_pwm = {

    .name = "exynos4210.pwm.pwm",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields = (VMStateField[]) {

        VMSTATE_UINT32(id, Exynos4210PWM),

        VMSTATE_UINT32(freq, Exynos4210PWM),

        VMSTATE_PTIMER(ptimer, Exynos4210PWM),

        VMSTATE_UINT32(reg_tcntb, Exynos4210PWM),

        VMSTATE_UINT32(reg_tcmpb, Exynos4210PWM),

        VMSTATE_END_OF_LIST()

    }

};

static const VMStateDescription vmstate_exynos4210_pwm_state = {

    .name = "exynos4210.pwm",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields = (VMStateField[]) {

        VMSTATE_UINT32_ARRAY(reg_tcfg, Exynos4210PWMState, 2),

        VMSTATE_UINT32(reg_tcon, Exynos4210PWMState),

        VMSTATE_UINT32(reg_tint_cstat, Exynos4210PWMState),

        VMSTATE_STRUCT_ARRAY(timer, Exynos4210PWMState,

            EXYNOS4210_PWM_TIMERS_NUM, 0,

        vmstate_exynos4210_pwm, Exynos4210PWM),

        VMSTATE_END_OF_LIST()

    }

};

/*

 * PWM update frequency

 */

static void exynos4210_pwm_update_freq(Exynos4210PWMState *s, uint32_t id)

{

    uint32_t freq;

    freq = s->timer[id].freq;

    if (id > 1) {

        s->timer[id].freq = 24000000 /

        ((GET_PRESCALER(s->reg_tcfg[0], 1) + 1) *

                (GET_DIVIDER(s->reg_tcfg[1], id)));

    } else {

        s->timer[id].freq = 24000000 /

        ((GET_PRESCALER(s->reg_tcfg[0], 0) + 1) *

                (GET_DIVIDER(s->reg_tcfg[1], id)));

    }

    if (freq != s->timer[id].freq) {

        ptimer_set_freq(s->timer[id].ptimer, s->timer[id].freq);

        DPRINTF("freq=%dHz\n", s->timer[id].freq);

    }

}

/*

 * Counter tick handler

 */

static void exynos4210_pwm_tick(void *opaque)

{

    Exynos4210PWM *s = (Exynos4210PWM *)opaque;

    Exynos4210PWMState *p = (Exynos4210PWMState *)s->parent;

    uint32_t id = s->id;

    bool cmp;

    DPRINTF("timer %d tick\n", id);

    /* set irq status */

    p->reg_tint_cstat |= TINT_CSTAT_STATUS(id);

    /* raise IRQ */

    if (p->reg_tint_cstat & TINT_CSTAT_ENABLE(id)) {

        DPRINTF("timer %d IRQ\n", id);

        qemu_irq_raise(p->timer[id].irq);

    }

    /* reload timer */

    if (id != 4) {

        cmp = p->reg_tcon & TCON_TIMER_AUTO_RELOAD(id);

    } else {

        cmp = p->reg_tcon & TCON_TIMER4_AUTO_RELOAD;

    }

    if (cmp) {

        DPRINTF("auto reload timer %d count to %x\n", id,

                p->timer[id].reg_tcntb);

        ptimer_set_count(p->timer[id].ptimer, p->timer[id].reg_tcntb);

        ptimer_run(p->timer[id].ptimer, 1);

    } else {

        /* stop timer, set status to STOP, see Basic Timer Operation */

        p->reg_tcon &= ~TCON_TIMER_START(id);

        ptimer_stop(p->timer[id].ptimer);

    }

}

/*

 * PWM Read

 */

static uint64_t exynos4210_pwm_read(void *opaque, hwaddr offset,

        unsigned size)

{

    Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;

    uint32_t value = 0;

    int index;

    switch (offset) {

    case TCFG0: case TCFG1:

        index = (offset - TCFG0) >> 2;

        value = s->reg_tcfg[index];

        break;

    case TCON:

        value = s->reg_tcon;

        break;

    case TCNTB0: case TCNTB1:

    case TCNTB2: case TCNTB3: case TCNTB4:

        index = (offset - TCNTB0) / 0xC;

        value = s->timer[index].reg_tcntb;

        break;

    case TCMPB0: case TCMPB1:

    case TCMPB2: case TCMPB3:

        index = (offset - TCMPB0) / 0xC;

        value = s->timer[index].reg_tcmpb;

        break;

    case TCNTO0: case TCNTO1:

    case TCNTO2: case TCNTO3: case TCNTO4:

        index = (offset == TCNTO4) ? 4 : (offset - TCNTO0) / 0xC;

        value = ptimer_get_count(s->timer[index].ptimer);

        break;

    case TINT_CSTAT:

        value = s->reg_tint_cstat;

        break;

    default:

        fprintf(stderr,

                "[exynos4210.pwm: bad read offset " TARGET_FMT_plx "]\n",

                offset);

        break;

    }

    return value;

}

/*

 * PWM Write

 */

static void exynos4210_pwm_write(void *opaque, hwaddr offset,

        uint64_t value, unsigned size)

{

    Exynos4210PWMState *s = (Exynos4210PWMState *)opaque;

    int index;

    uint32_t new_val;

    int i;

    switch (offset) {

    case TCFG0: case TCFG1:

        index = (offset - TCFG0) >> 2;

        s->reg_tcfg[index] = value;

        /* update timers frequencies */

        for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {

            exynos4210_pwm_update_freq(s, s->timer[i].id);

        }

        break;

    case TCON:

        for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {

            if ((value & TCON_TIMER_MANUAL_UPD(i)) >

            (s->reg_tcon & TCON_TIMER_MANUAL_UPD(i))) {

                /*

                 * TCNTB and TCMPB are loaded into TCNT and TCMP.

                 * Update timers.

                 */

                /* this will start timer to run, this ok, because

                 * during processing start bit timer will be stopped

                 * if needed */

                ptimer_set_count(s->timer[i].ptimer, s->timer[i].reg_tcntb);

                DPRINTF("set timer %d count to %x\n", i,

                        s->timer[i].reg_tcntb);

            }

            if ((value & TCON_TIMER_START(i)) >

            (s->reg_tcon & TCON_TIMER_START(i))) {

                /* changed to start */

                ptimer_run(s->timer[i].ptimer, 1);

                DPRINTF("run timer %d\n", i);

            }

            if ((value & TCON_TIMER_START(i)) <

                    (s->reg_tcon & TCON_TIMER_START(i))) {

                /* changed to stop */

                ptimer_stop(s->timer[i].ptimer);

                DPRINTF("stop timer %d\n", i);

            }

        }

        s->reg_tcon = value;

        break;

    case TCNTB0: case TCNTB1:

    case TCNTB2: case TCNTB3: case TCNTB4:

        index = (offset - TCNTB0) / 0xC;

        s->timer[index].reg_tcntb = value;

        break;

    case TCMPB0: case TCMPB1:

    case TCMPB2: case TCMPB3:

        index = (offset - TCMPB0) / 0xC;

        s->timer[index].reg_tcmpb = value;

        break;

    case TINT_CSTAT:

        new_val = (s->reg_tint_cstat & 0x3E0) + (0x1F & value);

        new_val &= ~(0x3E0 & value);

        for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {

            if ((new_val & TINT_CSTAT_STATUS(i)) <

                    (s->reg_tint_cstat & TINT_CSTAT_STATUS(i))) {

                qemu_irq_lower(s->timer[i].irq);

            }

        }

        s->reg_tint_cstat = new_val;

        break;

    default:

        fprintf(stderr,

                "[exynos4210.pwm: bad write offset " TARGET_FMT_plx "]\n",

                offset);

        break;

    }

}

/*

 * Set default values to timer fields and registers

 */

static void exynos4210_pwm_reset(DeviceState *d)

{

    Exynos4210PWMState *s = EXYNOS4210_PWM(d);

    int i;

    s->reg_tcfg[0] = 0x0101;

    s->reg_tcfg[1] = 0x0;

    s->reg_tcon = 0;

    s->reg_tint_cstat = 0;

    for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {

        s->timer[i].reg_tcmpb = 0;

        s->timer[i].reg_tcntb = 0;

        exynos4210_pwm_update_freq(s, s->timer[i].id);

        ptimer_stop(s->timer[i].ptimer);

    }

}

static const MemoryRegionOps exynos4210_pwm_ops = {

    .read = exynos4210_pwm_read,

    .write = exynos4210_pwm_write,

    .endianness = DEVICE_NATIVE_ENDIAN,

};

/*

 * PWM timer initialization

 */

static int exynos4210_pwm_init(SysBusDevice *dev)

{

    Exynos4210PWMState *s = EXYNOS4210_PWM(dev);

    int i;

    QEMUBH *bh;

    for (i = 0; i < EXYNOS4210_PWM_TIMERS_NUM; i++) {

        bh = qemu_bh_new(exynos4210_pwm_tick, &s->timer[i]);

        sysbus_init_irq(dev, &s->timer[i].irq);

        s->timer[i].ptimer = ptimer_init(bh);

        s->timer[i].id = i;

        s->timer[i].parent = s;

    }

    memory_region_init_io(&s->iomem, OBJECT(s), &exynos4210_pwm_ops, s,

                          "exynos4210-pwm", EXYNOS4210_PWM_REG_MEM_SIZE);

    sysbus_init_mmio(dev, &s->iomem);

    return 0;

}

static void exynos4210_pwm_class_init(ObjectClass *klass, void *data)

{

    DeviceClass *dc = DEVICE_CLASS(klass);

    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);

    k->init = exynos4210_pwm_init;

    dc->reset = exynos4210_pwm_reset;

    dc->vmsd = &vmstate_exynos4210_pwm_state;

}

static const TypeInfo exynos4210_pwm_info = {

    .name          = TYPE_EXYNOS4210_PWM,

    .parent        = TYPE_SYS_BUS_DEVICE,

    .instance_size = sizeof(Exynos4210PWMState),

    .class_init    = exynos4210_pwm_class_init,

};

static void exynos4210_pwm_register_types(void)

{

    type_register_static(&exynos4210_pwm_info);

}

type_init(exynos4210_pwm_register_types)