Archipelago » qemu

/*

 * TI OMAP2 general purpose timers emulation.

 *

 * Copyright (C) 2007-2008 Nokia Corporation

 * Written by Andrzej Zaborowski <andrew@openedhand.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 or

 * (at your option) any later version of the License.

 *

 * 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.h"

#include "qemu-timer.h"

#include "omap.h"

/* GP timers */

struct omap_gp_timer_s {

    MemoryRegion iomem;

    qemu_irq irq;

    qemu_irq wkup;

    qemu_irq in;

    qemu_irq out;

    omap_clk clk;

    QEMUTimer *timer;

    QEMUTimer *match;

    struct omap_target_agent_s *ta;

    int in_val;

    int out_val;

    int64_t time;

    int64_t rate;

    int64_t ticks_per_sec;

    int16_t config;

    int status;

    int it_ena;

    int wu_ena;

    int enable;

    int inout;

    int capt2;

    int pt;

    enum {

        gpt_trigger_none, gpt_trigger_overflow, gpt_trigger_both

    } trigger;

    enum {

        gpt_capture_none, gpt_capture_rising,

        gpt_capture_falling, gpt_capture_both

    } capture;

    int scpwm;

    int ce;

    int pre;

    int ptv;

    int ar;

    int st;

    int posted;

    uint32_t val;

    uint32_t load_val;

    uint32_t capture_val[2];

    uint32_t match_val;

    int capt_num;

    uint16_t writeh;        /* LSB */

    uint16_t readh;        /* MSB */

};

#define GPT_TCAR_IT        (1 << 2)

#define GPT_OVF_IT        (1 << 1)

#define GPT_MAT_IT        (1 << 0)

static inline void omap_gp_timer_intr(struct omap_gp_timer_s *timer, int it)

{

    if (timer->it_ena & it) {

        if (!timer->status)

            qemu_irq_raise(timer->irq);

        timer->status |= it;

        /* Or are the status bits set even when masked?

         * i.e. is masking applied before or after the status register?  */

    }

    if (timer->wu_ena & it)

        qemu_irq_pulse(timer->wkup);

}

static inline void omap_gp_timer_out(struct omap_gp_timer_s *timer, int level)

{

    if (!timer->inout && timer->out_val != level) {

        timer->out_val = level;

        qemu_set_irq(timer->out, level);

    }

}

static inline uint32_t omap_gp_timer_read(struct omap_gp_timer_s *timer)

{

    uint64_t distance;

    if (timer->st && timer->rate) {

        distance = qemu_get_clock_ns(vm_clock) - timer->time;

        distance = muldiv64(distance, timer->rate, timer->ticks_per_sec);

        if (distance >= 0xffffffff - timer->val)

            return 0xffffffff;

        else

            return timer->val + distance;

    } else

        return timer->val;

}

static inline void omap_gp_timer_sync(struct omap_gp_timer_s *timer)

{

    if (timer->st) {

        timer->val = omap_gp_timer_read(timer);

        timer->time = qemu_get_clock_ns(vm_clock);

    }

}

static inline void omap_gp_timer_update(struct omap_gp_timer_s *timer)

{

    int64_t expires, matches;

    if (timer->st && timer->rate) {

        expires = muldiv64(0x100000000ll - timer->val,

                        timer->ticks_per_sec, timer->rate);

        qemu_mod_timer(timer->timer, timer->time + expires);

        if (timer->ce && timer->match_val >= timer->val) {

            matches = muldiv64(timer->match_val - timer->val,

                            timer->ticks_per_sec, timer->rate);

            qemu_mod_timer(timer->match, timer->time + matches);

        } else

            qemu_del_timer(timer->match);

    } else {

        qemu_del_timer(timer->timer);

        qemu_del_timer(timer->match);

        omap_gp_timer_out(timer, timer->scpwm);

    }

}

static inline void omap_gp_timer_trigger(struct omap_gp_timer_s *timer)

{

    if (timer->pt)

        /* TODO in overflow-and-match mode if the first event to

         * occur is the match, don't toggle.  */

        omap_gp_timer_out(timer, !timer->out_val);

    else

        /* TODO inverted pulse on timer->out_val == 1?  */

        qemu_irq_pulse(timer->out);

}

static void omap_gp_timer_tick(void *opaque)

{

    struct omap_gp_timer_s *timer = (struct omap_gp_timer_s *) opaque;

    if (!timer->ar) {

        timer->st = 0;

        timer->val = 0;

    } else {

        timer->val = timer->load_val;

        timer->time = qemu_get_clock_ns(vm_clock);

    }

    if (timer->trigger == gpt_trigger_overflow ||

                    timer->trigger == gpt_trigger_both)

        omap_gp_timer_trigger(timer);

    omap_gp_timer_intr(timer, GPT_OVF_IT);

    omap_gp_timer_update(timer);

}

static void omap_gp_timer_match(void *opaque)

{

    struct omap_gp_timer_s *timer = (struct omap_gp_timer_s *) opaque;

    if (timer->trigger == gpt_trigger_both)

        omap_gp_timer_trigger(timer);

    omap_gp_timer_intr(timer, GPT_MAT_IT);

}

static void omap_gp_timer_input(void *opaque, int line, int on)

{

    struct omap_gp_timer_s *s = (struct omap_gp_timer_s *) opaque;

    int trigger;

    switch (s->capture) {

    default:

    case gpt_capture_none:

        trigger = 0;

        break;

    case gpt_capture_rising:

        trigger = !s->in_val && on;

        break;

    case gpt_capture_falling:

        trigger = s->in_val && !on;

        break;

    case gpt_capture_both:

        trigger = (s->in_val == !on);

        break;

    }

    s->in_val = on;

    if (s->inout && trigger && s->capt_num < 2) {

        s->capture_val[s->capt_num] = omap_gp_timer_read(s);

        if (s->capt2 == s->capt_num ++)

            omap_gp_timer_intr(s, GPT_TCAR_IT);

    }

}

static void omap_gp_timer_clk_update(void *opaque, int line, int on)

{

    struct omap_gp_timer_s *timer = (struct omap_gp_timer_s *) opaque;

    omap_gp_timer_sync(timer);

    timer->rate = on ? omap_clk_getrate(timer->clk) : 0;

    omap_gp_timer_update(timer);

}

static void omap_gp_timer_clk_setup(struct omap_gp_timer_s *timer)

{

    omap_clk_adduser(timer->clk,

                    qemu_allocate_irqs(omap_gp_timer_clk_update, timer, 1)[0]);

    timer->rate = omap_clk_getrate(timer->clk);

}

void omap_gp_timer_reset(struct omap_gp_timer_s *s)

{

    s->config = 0x000;

    s->status = 0;

    s->it_ena = 0;

    s->wu_ena = 0;

    s->inout = 0;

    s->capt2 = 0;

    s->capt_num = 0;

    s->pt = 0;

    s->trigger = gpt_trigger_none;

    s->capture = gpt_capture_none;

    s->scpwm = 0;

    s->ce = 0;

    s->pre = 0;

    s->ptv = 0;

    s->ar = 0;

    s->st = 0;

    s->posted = 1;

    s->val = 0x00000000;

    s->load_val = 0x00000000;

    s->capture_val[0] = 0x00000000;

    s->capture_val[1] = 0x00000000;

    s->match_val = 0x00000000;

    omap_gp_timer_update(s);

}

static uint32_t omap_gp_timer_readw(void *opaque, hwaddr addr)

{

    struct omap_gp_timer_s *s = (struct omap_gp_timer_s *) opaque;

    switch (addr) {

    case 0x00:        /* TIDR */

        return 0x21;

    case 0x10:        /* TIOCP_CFG */

        return s->config;

    case 0x14:        /* TISTAT */

        /* ??? When's this bit reset? */

        return 1;                                                /* RESETDONE */

    case 0x18:        /* TISR */

        return s->status;

    case 0x1c:        /* TIER */

        return s->it_ena;

    case 0x20:        /* TWER */

        return s->wu_ena;

    case 0x24:        /* TCLR */

        return (s->inout << 14) |

                (s->capt2 << 13) |

                (s->pt << 12) |

                (s->trigger << 10) |

                (s->capture << 8) |

                (s->scpwm << 7) |

                (s->ce << 6) |

                (s->pre << 5) |

                (s->ptv << 2) |

                (s->ar << 1) |

                (s->st << 0);

    case 0x28:        /* TCRR */

        return omap_gp_timer_read(s);

    case 0x2c:        /* TLDR */

        return s->load_val;

    case 0x30:        /* TTGR */

        return 0xffffffff;

    case 0x34:        /* TWPS */

        return 0x00000000;        /* No posted writes pending.  */

    case 0x38:        /* TMAR */

        return s->match_val;

    case 0x3c:        /* TCAR1 */

        return s->capture_val[0];

    case 0x40:        /* TSICR */

        return s->posted << 2;

    case 0x44:        /* TCAR2 */

        return s->capture_val[1];

    }

    OMAP_BAD_REG(addr);

    return 0;

}

static uint32_t omap_gp_timer_readh(void *opaque, hwaddr addr)

{

    struct omap_gp_timer_s *s = (struct omap_gp_timer_s *) opaque;

    uint32_t ret;

    if (addr & 2)

        return s->readh;

    else {

        ret = omap_gp_timer_readw(opaque, addr);

        s->readh = ret >> 16;

        return ret & 0xffff;

    }

}

static void omap_gp_timer_write(void *opaque, hwaddr addr,

                uint32_t value)

{

    struct omap_gp_timer_s *s = (struct omap_gp_timer_s *) opaque;

    switch (addr) {

    case 0x00:        /* TIDR */

    case 0x14:        /* TISTAT */

    case 0x34:        /* TWPS */

    case 0x3c:        /* TCAR1 */

    case 0x44:        /* TCAR2 */

        OMAP_RO_REG(addr);

        break;

    case 0x10:        /* TIOCP_CFG */

        s->config = value & 0x33d;

        if (((value >> 3) & 3) == 3)                                /* IDLEMODE */

            fprintf(stderr, "%s: illegal IDLEMODE value in TIOCP_CFG\n",

                            __FUNCTION__);

        if (value & 2)                                                /* SOFTRESET */

            omap_gp_timer_reset(s);

        break;

    case 0x18:        /* TISR */

        if (value & GPT_TCAR_IT)

            s->capt_num = 0;

        if (s->status && !(s->status &= ~value))

            qemu_irq_lower(s->irq);

        break;

    case 0x1c:        /* TIER */

        s->it_ena = value & 7;

        break;

    case 0x20:        /* TWER */

        s->wu_ena = value & 7;

        break;

    case 0x24:        /* TCLR */

        omap_gp_timer_sync(s);

        s->inout = (value >> 14) & 1;

        s->capt2 = (value >> 13) & 1;

        s->pt = (value >> 12) & 1;

        s->trigger = (value >> 10) & 3;

        if (s->capture == gpt_capture_none &&

                        ((value >> 8) & 3) != gpt_capture_none)

            s->capt_num = 0;

        s->capture = (value >> 8) & 3;

        s->scpwm = (value >> 7) & 1;

        s->ce = (value >> 6) & 1;

        s->pre = (value >> 5) & 1;

        s->ptv = (value >> 2) & 7;

        s->ar = (value >> 1) & 1;

        s->st = (value >> 0) & 1;

        if (s->inout && s->trigger != gpt_trigger_none)

            fprintf(stderr, "%s: GP timer pin must be an output "

                            "for this trigger mode\n", __FUNCTION__);

        if (!s->inout && s->capture != gpt_capture_none)

            fprintf(stderr, "%s: GP timer pin must be an input "

                            "for this capture mode\n", __FUNCTION__);

        if (s->trigger == gpt_trigger_none)

            omap_gp_timer_out(s, s->scpwm);

        /* TODO: make sure this doesn't overflow 32-bits */

        s->ticks_per_sec = get_ticks_per_sec() << (s->pre ? s->ptv + 1 : 0);

        omap_gp_timer_update(s);

        break;

    case 0x28:        /* TCRR */

        s->time = qemu_get_clock_ns(vm_clock);

        s->val = value;

        omap_gp_timer_update(s);

        break;

    case 0x2c:        /* TLDR */

        s->load_val = value;

        break;

    case 0x30:        /* TTGR */

        s->time = qemu_get_clock_ns(vm_clock);

        s->val = s->load_val;

        omap_gp_timer_update(s);

        break;

    case 0x38:        /* TMAR */

        omap_gp_timer_sync(s);

        s->match_val = value;

        omap_gp_timer_update(s);

        break;

    case 0x40:        /* TSICR */

        s->posted = (value >> 2) & 1;

        if (value & 2)        /* How much exactly are we supposed to reset? */

            omap_gp_timer_reset(s);

        break;

    default:

        OMAP_BAD_REG(addr);

    }

}

static void omap_gp_timer_writeh(void *opaque, hwaddr addr,

                uint32_t value)

{

    struct omap_gp_timer_s *s = (struct omap_gp_timer_s *) opaque;

    if (addr & 2)

        return omap_gp_timer_write(opaque, addr, (value << 16) | s->writeh);

    else

        s->writeh = (uint16_t) value;

}

static const MemoryRegionOps omap_gp_timer_ops = {

    .old_mmio = {

        .read = {

            omap_badwidth_read32,

            omap_gp_timer_readh,

            omap_gp_timer_readw,

        },

        .write = {

            omap_badwidth_write32,

            omap_gp_timer_writeh,

            omap_gp_timer_write,

        },

    },

    .endianness = DEVICE_NATIVE_ENDIAN,

};

struct omap_gp_timer_s *omap_gp_timer_init(struct omap_target_agent_s *ta,

                qemu_irq irq, omap_clk fclk, omap_clk iclk)

{

    struct omap_gp_timer_s *s = (struct omap_gp_timer_s *)

            g_malloc0(sizeof(struct omap_gp_timer_s));

    s->ta = ta;

    s->irq = irq;

    s->clk = fclk;

    s->timer = qemu_new_timer_ns(vm_clock, omap_gp_timer_tick, s);

    s->match = qemu_new_timer_ns(vm_clock, omap_gp_timer_match, s);

    s->in = qemu_allocate_irqs(omap_gp_timer_input, s, 1)[0];

    omap_gp_timer_reset(s);

    omap_gp_timer_clk_setup(s);

    memory_region_init_io(&s->iomem, &omap_gp_timer_ops, s, "omap.gptimer",

                          omap_l4_region_size(ta, 0));

    omap_l4_attach(ta, 0, &s->iomem);

    return s;

}