/*

 * On-chip DMA controller framework.

 *

 * Copyright (C) 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) version 3 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, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,

 * MA 02111-1307 USA

 */

#include "qemu-common.h"

#include "qemu-timer.h"

#include "soc_dma.h"

static void transfer_mem2mem(struct soc_dma_ch_s *ch)

{

    memcpy(ch->paddr[0], ch->paddr[1], ch->bytes);

    ch->paddr[0] += ch->bytes;

    ch->paddr[1] += ch->bytes;

}

static void transfer_mem2fifo(struct soc_dma_ch_s *ch)

{

    ch->io_fn[1](ch->io_opaque[1], ch->paddr[0], ch->bytes);

    ch->paddr[0] += ch->bytes;

}

static void transfer_fifo2mem(struct soc_dma_ch_s *ch)

{

    ch->io_fn[0](ch->io_opaque[0], ch->paddr[1], ch->bytes);

    ch->paddr[1] += ch->bytes;

}

/* This is further optimisable but isn't very important because often

 * DMA peripherals forbid this kind of transfers and even when they don't,

 * oprating systems may not need to use them.  */

static void *fifo_buf;

static int fifo_size;

static void transfer_fifo2fifo(struct soc_dma_ch_s *ch)

{

    if (ch->bytes > fifo_size)

        fifo_buf = qemu_realloc(fifo_buf, fifo_size = ch->bytes);

    /* Implement as transfer_fifo2linear + transfer_linear2fifo.  */

    ch->io_fn[0](ch->io_opaque[0], fifo_buf, ch->bytes);

    ch->io_fn[1](ch->io_opaque[1], fifo_buf, ch->bytes);

}

struct dma_s {

    struct soc_dma_s soc;

    int chnum;

    uint64_t ch_enable_mask;

    int64_t channel_freq;

    int enabled_count;

    struct memmap_entry_s {

        enum soc_dma_port_type type;

        target_phys_addr_t addr;

        union {

           struct {

               void *opaque;

               soc_dma_io_t fn;

               int out;

           } fifo;

           struct {

               void *base;

               size_t size;

           } mem;

        } u;

    } *memmap;

    int memmap_size;

    struct soc_dma_ch_s ch[0];

};

static void soc_dma_ch_schedule(struct soc_dma_ch_s *ch, int delay_bytes)

{

    int64_t now = qemu_get_clock(vm_clock);

    struct dma_s *dma = (struct dma_s *) ch->dma;

    qemu_mod_timer(ch->timer, now + delay_bytes / dma->channel_freq);

}

static void soc_dma_ch_run(void *opaque)

{

    struct soc_dma_ch_s *ch = (struct soc_dma_ch_s *) opaque;

    ch->running = 1;

    ch->dma->setup_fn(ch);

    ch->transfer_fn(ch);

    ch->running = 0;

    if (ch->enable)

        soc_dma_ch_schedule(ch, ch->bytes);

    ch->bytes = 0;

}

static inline struct memmap_entry_s *soc_dma_lookup(struct dma_s *dma,

                target_phys_addr_t addr)

{

    struct memmap_entry_s *lo;

    int hi;

    lo = dma->memmap;

    hi = dma->memmap_size;

    while (hi > 1) {

        hi /= 2;

        if (lo[hi].addr <= addr)

            lo += hi;

    }

    return lo;

}

static inline enum soc_dma_port_type soc_dma_ch_update_type(

                struct soc_dma_ch_s *ch, int port)

{

    struct dma_s *dma = (struct dma_s *) ch->dma;

    struct memmap_entry_s *entry = soc_dma_lookup(dma, ch->vaddr[port]);

    if (entry->type == soc_dma_port_fifo) {

        while (entry < dma->memmap + dma->memmap_size &&

                        entry->u.fifo.out != port)

            entry ++;

        if (entry->addr != ch->vaddr[port] || entry->u.fifo.out != port)

            return soc_dma_port_other;

        if (ch->type[port] != soc_dma_access_const)

            return soc_dma_port_other;

        ch->io_fn[port] = entry->u.fifo.fn;

        ch->io_opaque[port] = entry->u.fifo.opaque;

        return soc_dma_port_fifo;

    } else if (entry->type == soc_dma_port_mem) {

        if (entry->addr > ch->vaddr[port] ||

                        entry->addr + entry->u.mem.size <= ch->vaddr[port])

            return soc_dma_port_other;

        /* TODO: support constant memory address for source port as used for

         * drawing solid rectangles by PalmOS(R).  */

        if (ch->type[port] != soc_dma_access_const)

            return soc_dma_port_other;

        ch->paddr[port] = (uint8_t *) entry->u.mem.base +

                (ch->vaddr[port] - entry->addr);

        /* TODO: save bytes left to the end of the mapping somewhere so we

         * can check we're not reading beyond it.  */

        return soc_dma_port_mem;

    } else

        return soc_dma_port_other;

}

void soc_dma_ch_update(struct soc_dma_ch_s *ch)

{

    enum soc_dma_port_type src, dst;

    src = soc_dma_ch_update_type(ch, 0);

    if (src == soc_dma_port_other) {

        ch->update = 0;

        ch->transfer_fn = ch->dma->transfer_fn;

        return;

    }

    dst = soc_dma_ch_update_type(ch, 1);

    /* TODO: use src and dst as array indices.  */

    if (src == soc_dma_port_mem && dst == soc_dma_port_mem)

        ch->transfer_fn = transfer_mem2mem;

    else if (src == soc_dma_port_mem && dst == soc_dma_port_fifo)

        ch->transfer_fn = transfer_mem2fifo;

    else if (src == soc_dma_port_fifo && dst == soc_dma_port_mem)

        ch->transfer_fn = transfer_fifo2mem;

    else if (src == soc_dma_port_fifo && dst == soc_dma_port_fifo)

        ch->transfer_fn = transfer_fifo2fifo;

    else

        ch->transfer_fn = ch->dma->transfer_fn;

    ch->update = (dst != soc_dma_port_other);

}

static void soc_dma_ch_freq_update(struct dma_s *s)

{

    if (s->enabled_count)

        /* We completely ignore channel priorities and stuff */

        s->channel_freq = s->soc.freq / s->enabled_count;

    else

        /* TODO: Signal that we want to disable the functional clock and let

         * the platform code decide what to do with it, i.e. check that

         * auto-idle is enabled in the clock controller and if we are stopping

         * the clock, do the same with any parent clocks that had only one

         * user keeping them on and auto-idle enabled.  */;

}

void soc_dma_set_request(struct soc_dma_ch_s *ch, int level)

{

    struct dma_s *dma = (struct dma_s *) ch->dma;

    dma->enabled_count += level - ch->enable;

    if (level)

        dma->ch_enable_mask |= 1 << ch->num;

    else

        dma->ch_enable_mask &= ~(1 << ch->num);

    if (level != ch->enable) {

        soc_dma_ch_freq_update(dma);

        ch->enable = level;

        if (!ch->enable)

            qemu_del_timer(ch->timer);

        else if (!ch->running)

            soc_dma_ch_run(ch);

        else

            soc_dma_ch_schedule(ch, 1);

    }

}

void soc_dma_reset(struct soc_dma_s *soc)

{

    struct dma_s *s = (struct dma_s *) soc;

    s->soc.drqbmp = 0;

    s->ch_enable_mask = 0;

    s->enabled_count = 0;

    soc_dma_ch_freq_update(s);

}

/* TODO: take a functional-clock argument */

struct soc_dma_s *soc_dma_init(int n)

{

    int i;

    struct dma_s *s = qemu_mallocz(sizeof(*s) + n * sizeof(*s->ch));

    s->chnum = n;

    s->soc.ch = s->ch;

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

        s->ch[i].dma = &s->soc;

        s->ch[i].num = i;

        s->ch[i].timer = qemu_new_timer(vm_clock, soc_dma_ch_run, &s->ch[i]);

    }

    soc_dma_reset(&s->soc);

    fifo_size = 0;

    return &s->soc;

}

void soc_dma_port_add_fifo(struct soc_dma_s *soc, target_phys_addr_t virt_base,

                soc_dma_io_t fn, void *opaque, int out)

{

    struct memmap_entry_s *entry;

    struct dma_s *dma = (struct dma_s *) soc;

    dma->memmap = qemu_realloc(dma->memmap, sizeof(*entry) *

                    (dma->memmap_size + 1));

    entry = soc_dma_lookup(dma, virt_base);

    if (dma->memmap_size) {

        if (entry->type == soc_dma_port_mem) {

            if (entry->addr <= virt_base &&

                            entry->addr + entry->u.mem.size > virt_base) {

                fprintf(stderr, "%s: FIFO at " TARGET_FMT_lx

                                " collides with RAM region at " TARGET_FMT_lx

                                "-" TARGET_FMT_lx "\n", __FUNCTION__,

                                (target_ulong) virt_base,

                                (target_ulong) entry->addr, (target_ulong)

                                (entry->addr + entry->u.mem.size));

                exit(-1);

            }

            if (entry->addr <= virt_base)

                entry ++;

        } else

            while (entry < dma->memmap + dma->memmap_size &&

                            entry->addr <= virt_base) {

                if (entry->addr == virt_base && entry->u.fifo.out == out) {

                    fprintf(stderr, "%s: FIFO at " TARGET_FMT_lx

                                    " collides FIFO at " TARGET_FMT_lx "\n",

                                    __FUNCTION__, (target_ulong) virt_base,

                                    (target_ulong) entry->addr);

                    exit(-1);

                }

                entry ++;

            }

        memmove(entry + 1, entry,

                        (uint8_t *) (dma->memmap + dma->memmap_size ++) -

                        (uint8_t *) entry);

    } else

        dma->memmap_size ++;

    entry->addr          = virt_base;

    entry->type          = soc_dma_port_fifo;

    entry->u.fifo.fn     = fn;

    entry->u.fifo.opaque = opaque;

    entry->u.fifo.out    = out;

}

void soc_dma_port_add_mem(struct soc_dma_s *soc, uint8_t *phys_base,

                target_phys_addr_t virt_base, size_t size)

{

    struct memmap_entry_s *entry;

    struct dma_s *dma = (struct dma_s *) soc;

    dma->memmap = qemu_realloc(dma->memmap, sizeof(*entry) *

                    (dma->memmap_size + 1));

    entry = soc_dma_lookup(dma, virt_base);

    if (dma->memmap_size) {

        if (entry->type == soc_dma_port_mem) {

            if ((entry->addr >= virt_base && entry->addr < virt_base + size) ||

                            (entry->addr <= virt_base &&

                             entry->addr + entry->u.mem.size > virt_base)) {

                fprintf(stderr, "%s: RAM at " TARGET_FMT_lx "-" TARGET_FMT_lx

                                " collides with RAM region at " TARGET_FMT_lx

                                "-" TARGET_FMT_lx "\n", __FUNCTION__,

                                (target_ulong) virt_base,

                                (target_ulong) (virt_base + size),

                                (target_ulong) entry->addr, (target_ulong)

                                (entry->addr + entry->u.mem.size));

                exit(-1);

            }

            if (entry->addr <= virt_base)

                entry ++;

        } else {

            if (entry->addr >= virt_base &&

                            entry->addr < virt_base + size) {

                fprintf(stderr, "%s: RAM at " TARGET_FMT_lx "-" TARGET_FMT_lx

                                " collides with FIFO at " TARGET_FMT_lx

                                "\n", __FUNCTION__,

                                (target_ulong) virt_base,

                                (target_ulong) (virt_base + size),

                                (target_ulong) entry->addr);

                exit(-1);

            }

            while (entry < dma->memmap + dma->memmap_size &&

                            entry->addr <= virt_base)

                entry ++;

	}

        memmove(entry + 1, entry,

                        (uint8_t *) (dma->memmap + dma->memmap_size ++) -

                        (uint8_t *) entry);

    } else

        dma->memmap_size ++;

    entry->addr          = virt_base;

    entry->type          = soc_dma_port_mem;

    entry->u.mem.base    = phys_base;

    entry->u.mem.size    = size;

}

/* TODO: port removal for ports like PCMCIA memory */