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/*

 * Intel XScale PXA255/270 DMA controller.

 *

 * Copyright (c) 2006 Openedhand Ltd.

 * Copyright (c) 2006 Thorsten Zitterell

 * Written by Andrzej Zaborowski <balrog@zabor.org>

 *

 * This code is licenced under the GPL.

 */

#include "hw.h"

#include "pxa.h"

typedef struct {

    target_phys_addr_t descr;

    target_phys_addr_t src;

    target_phys_addr_t dest;

    uint32_t cmd;

    uint32_t state;

    int request;

} PXA2xxDMAChannel;

/* Allow the DMA to be used as a PIC.  */

typedef void (*pxa2xx_dma_handler_t)(void *opaque, int irq, int level);

struct PXA2xxDMAState {

    pxa2xx_dma_handler_t handler;

    qemu_irq irq;

    uint32_t stopintr;

    uint32_t eorintr;

    uint32_t rasintr;

    uint32_t startintr;

    uint32_t endintr;

    uint32_t align;

    uint32_t pio;

    int channels;

    PXA2xxDMAChannel *chan;

    uint8_t *req;

    /* Flag to avoid recursive DMA invocations.  */

    int running;

};

#define PXA255_DMA_NUM_CHANNELS        16

#define PXA27X_DMA_NUM_CHANNELS        32

#define PXA2XX_DMA_NUM_REQUESTS        75

#define DCSR0        0x0000        /* DMA Control / Status register for Channel 0 */

#define DCSR31        0x007c        /* DMA Control / Status register for Channel 31 */

#define DALGN        0x00a0        /* DMA Alignment register */

#define DPCSR        0x00a4        /* DMA Programmed I/O Control Status register */

#define DRQSR0        0x00e0        /* DMA DREQ<0> Status register */

#define DRQSR1        0x00e4        /* DMA DREQ<1> Status register */

#define DRQSR2        0x00e8        /* DMA DREQ<2> Status register */

#define DINT        0x00f0        /* DMA Interrupt register */

#define DRCMR0        0x0100        /* Request to Channel Map register 0 */

#define DRCMR63        0x01fc        /* Request to Channel Map register 63 */

#define D_CH0        0x0200        /* Channel 0 Descriptor start */

#define DRCMR64        0x1100        /* Request to Channel Map register 64 */

#define DRCMR74        0x1128        /* Request to Channel Map register 74 */

/* Per-channel register */

#define DDADR        0x00

#define DSADR        0x01

#define DTADR        0x02

#define DCMD        0x03

/* Bit-field masks */

#define DRCMR_CHLNUM                0x1f

#define DRCMR_MAPVLD                (1 << 7)

#define DDADR_STOP                (1 << 0)

#define DDADR_BREN                (1 << 1)

#define DCMD_LEN                0x1fff

#define DCMD_WIDTH(x)                (1 << ((((x) >> 14) & 3) - 1))

#define DCMD_SIZE(x)                (4 << (((x) >> 16) & 3))

#define DCMD_FLYBYT                (1 << 19)

#define DCMD_FLYBYS                (1 << 20)

#define DCMD_ENDIRQEN                (1 << 21)

#define DCMD_STARTIRQEN                (1 << 22)

#define DCMD_CMPEN                (1 << 25)

#define DCMD_FLOWTRG                (1 << 28)

#define DCMD_FLOWSRC                (1 << 29)

#define DCMD_INCTRGADDR                (1 << 30)

#define DCMD_INCSRCADDR                (1 << 31)

#define DCSR_BUSERRINTR                (1 << 0)

#define DCSR_STARTINTR                (1 << 1)

#define DCSR_ENDINTR                (1 << 2)

#define DCSR_STOPINTR                (1 << 3)

#define DCSR_RASINTR                (1 << 4)

#define DCSR_REQPEND                (1 << 8)

#define DCSR_EORINT                (1 << 9)

#define DCSR_CMPST                (1 << 10)

#define DCSR_MASKRUN                (1 << 22)

#define DCSR_RASIRQEN                (1 << 23)

#define DCSR_CLRCMPST                (1 << 24)

#define DCSR_SETCMPST                (1 << 25)

#define DCSR_EORSTOPEN                (1 << 26)

#define DCSR_EORJMPEN                (1 << 27)

#define DCSR_EORIRQEN                (1 << 28)

#define DCSR_STOPIRQEN                (1 << 29)

#define DCSR_NODESCFETCH        (1 << 30)

#define DCSR_RUN                (1 << 31)

static inline void pxa2xx_dma_update(PXA2xxDMAState *s, int ch)

{

    if (ch >= 0) {

        if ((s->chan[ch].state & DCSR_STOPIRQEN) &&

                (s->chan[ch].state & DCSR_STOPINTR))

            s->stopintr |= 1 << ch;

        else

            s->stopintr &= ~(1 << ch);

        if ((s->chan[ch].state & DCSR_EORIRQEN) &&

                (s->chan[ch].state & DCSR_EORINT))

            s->eorintr |= 1 << ch;

        else

            s->eorintr &= ~(1 << ch);

        if ((s->chan[ch].state & DCSR_RASIRQEN) &&

                (s->chan[ch].state & DCSR_RASINTR))

            s->rasintr |= 1 << ch;

        else

            s->rasintr &= ~(1 << ch);

        if (s->chan[ch].state & DCSR_STARTINTR)

            s->startintr |= 1 << ch;

        else

            s->startintr &= ~(1 << ch);

        if (s->chan[ch].state & DCSR_ENDINTR)

            s->endintr |= 1 << ch;

        else

            s->endintr &= ~(1 << ch);

    }

    if (s->stopintr | s->eorintr | s->rasintr | s->startintr | s->endintr)

        qemu_irq_raise(s->irq);

    else

        qemu_irq_lower(s->irq);

}

static inline void pxa2xx_dma_descriptor_fetch(

                PXA2xxDMAState *s, int ch)

{

    uint32_t desc[4];

    target_phys_addr_t daddr = s->chan[ch].descr & ~0xf;

    if ((s->chan[ch].descr & DDADR_BREN) && (s->chan[ch].state & DCSR_CMPST))

        daddr += 32;

    cpu_physical_memory_read(daddr, (uint8_t *) desc, 16);

    s->chan[ch].descr = desc[DDADR];

    s->chan[ch].src = desc[DSADR];

    s->chan[ch].dest = desc[DTADR];

    s->chan[ch].cmd = desc[DCMD];

    if (s->chan[ch].cmd & DCMD_FLOWSRC)

        s->chan[ch].src &= ~3;

    if (s->chan[ch].cmd & DCMD_FLOWTRG)

        s->chan[ch].dest &= ~3;

    if (s->chan[ch].cmd & (DCMD_CMPEN | DCMD_FLYBYS | DCMD_FLYBYT))

        printf("%s: unsupported mode in channel %i\n", __FUNCTION__, ch);

    if (s->chan[ch].cmd & DCMD_STARTIRQEN)

        s->chan[ch].state |= DCSR_STARTINTR;

}

static void pxa2xx_dma_run(PXA2xxDMAState *s)

{

    int c, srcinc, destinc;

    uint32_t n, size;

    uint32_t width;

    uint32_t length;

    uint8_t buffer[32];

    PXA2xxDMAChannel *ch;

    if (s->running ++)

        return;

    while (s->running) {

        s->running = 1;

        for (c = 0; c < s->channels; c ++) {

            ch = &s->chan[c];

            while ((ch->state & DCSR_RUN) && !(ch->state & DCSR_STOPINTR)) {

                /* Test for pending requests */

                if ((ch->cmd & (DCMD_FLOWSRC | DCMD_FLOWTRG)) && !ch->request)

                    break;

                length = ch->cmd & DCMD_LEN;

                size = DCMD_SIZE(ch->cmd);

                width = DCMD_WIDTH(ch->cmd);

                srcinc = (ch->cmd & DCMD_INCSRCADDR) ? width : 0;

                destinc = (ch->cmd & DCMD_INCTRGADDR) ? width : 0;

                while (length) {

                    size = MIN(length, size);

                    for (n = 0; n < size; n += width) {

                        cpu_physical_memory_read(ch->src, buffer + n, width);

                        ch->src += srcinc;

                    }

                    for (n = 0; n < size; n += width) {

                        cpu_physical_memory_write(ch->dest, buffer + n, width);

                        ch->dest += destinc;

                    }

                    length -= size;

                    if ((ch->cmd & (DCMD_FLOWSRC | DCMD_FLOWTRG)) &&

                            !ch->request) {

                        ch->state |= DCSR_EORINT;

                        if (ch->state & DCSR_EORSTOPEN)

                            ch->state |= DCSR_STOPINTR;

                        if ((ch->state & DCSR_EORJMPEN) &&

                                        !(ch->state & DCSR_NODESCFETCH))

                            pxa2xx_dma_descriptor_fetch(s, c);

                        break;

                    }

                }

                ch->cmd = (ch->cmd & ~DCMD_LEN) | length;

                /* Is the transfer complete now? */

                if (!length) {

                    if (ch->cmd & DCMD_ENDIRQEN)

                        ch->state |= DCSR_ENDINTR;

                    if ((ch->state & DCSR_NODESCFETCH) ||

                                (ch->descr & DDADR_STOP) ||

                                (ch->state & DCSR_EORSTOPEN)) {

                        ch->state |= DCSR_STOPINTR;

                        ch->state &= ~DCSR_RUN;

                        break;

                    }

                    ch->state |= DCSR_STOPINTR;

                    break;

                }

            }

        }

        s->running --;

    }

}

static uint32_t pxa2xx_dma_read(void *opaque, target_phys_addr_t offset)

{

    PXA2xxDMAState *s = (PXA2xxDMAState *) opaque;

    unsigned int channel;

    switch (offset) {

    case DRCMR64 ... DRCMR74:

        offset -= DRCMR64 - DRCMR0 - (64 << 2);

        /* Fall through */

    case DRCMR0 ... DRCMR63:

        channel = (offset - DRCMR0) >> 2;

        return s->req[channel];

    case DRQSR0:

    case DRQSR1:

    case DRQSR2:

        return 0;

    case DCSR0 ... DCSR31:

        channel = offset >> 2;

        if (s->chan[channel].request)

            return s->chan[channel].state | DCSR_REQPEND;

        return s->chan[channel].state;

    case DINT:

        return s->stopintr | s->eorintr | s->rasintr |

                s->startintr | s->endintr;

    case DALGN:

        return s->align;

    case DPCSR:

        return s->pio;

    }

    if (offset >= D_CH0 && offset < D_CH0 + (s->channels << 4)) {

        channel = (offset - D_CH0) >> 4;

        switch ((offset & 0x0f) >> 2) {

        case DDADR:

            return s->chan[channel].descr;

        case DSADR:

            return s->chan[channel].src;

        case DTADR:

            return s->chan[channel].dest;

        case DCMD:

            return s->chan[channel].cmd;

        }

    }

    hw_error("%s: Bad offset 0x" TARGET_FMT_plx "\n", __FUNCTION__, offset);

    return 7;

}

static void pxa2xx_dma_write(void *opaque,

                 target_phys_addr_t offset, uint32_t value)

{

    PXA2xxDMAState *s = (PXA2xxDMAState *) opaque;

    unsigned int channel;

    switch (offset) {

    case DRCMR64 ... DRCMR74:

        offset -= DRCMR64 - DRCMR0 - (64 << 2);

        /* Fall through */

    case DRCMR0 ... DRCMR63:

        channel = (offset - DRCMR0) >> 2;

        if (value & DRCMR_MAPVLD)

            if ((value & DRCMR_CHLNUM) > s->channels)

                hw_error("%s: Bad DMA channel %i\n",

                         __FUNCTION__, value & DRCMR_CHLNUM);

        s->req[channel] = value;

        break;

    case DRQSR0:

    case DRQSR1:

    case DRQSR2:

        /* Nothing to do */

        break;

    case DCSR0 ... DCSR31:

        channel = offset >> 2;

        s->chan[channel].state &= 0x0000071f & ~(value &

                        (DCSR_EORINT | DCSR_ENDINTR |

                         DCSR_STARTINTR | DCSR_BUSERRINTR));

        s->chan[channel].state |= value & 0xfc800000;

        if (s->chan[channel].state & DCSR_STOPIRQEN)

            s->chan[channel].state &= ~DCSR_STOPINTR;

        if (value & DCSR_NODESCFETCH) {

            /* No-descriptor-fetch mode */

            if (value & DCSR_RUN) {

                s->chan[channel].state &= ~DCSR_STOPINTR;

                pxa2xx_dma_run(s);

            }

        } else {

            /* Descriptor-fetch mode */

            if (value & DCSR_RUN) {

                s->chan[channel].state &= ~DCSR_STOPINTR;

                pxa2xx_dma_descriptor_fetch(s, channel);

                pxa2xx_dma_run(s);

            }

        }

        /* Shouldn't matter as our DMA is synchronous.  */

        if (!(value & (DCSR_RUN | DCSR_MASKRUN)))

            s->chan[channel].state |= DCSR_STOPINTR;

        if (value & DCSR_CLRCMPST)

            s->chan[channel].state &= ~DCSR_CMPST;

        if (value & DCSR_SETCMPST)

            s->chan[channel].state |= DCSR_CMPST;

        pxa2xx_dma_update(s, channel);

        break;

    case DALGN:

        s->align = value;

        break;

    case DPCSR:

        s->pio = value & 0x80000001;

        break;

    default:

        if (offset >= D_CH0 && offset < D_CH0 + (s->channels << 4)) {

            channel = (offset - D_CH0) >> 4;

            switch ((offset & 0x0f) >> 2) {

            case DDADR:

                s->chan[channel].descr = value;

                break;

            case DSADR:

                s->chan[channel].src = value;

                break;

            case DTADR:

                s->chan[channel].dest = value;

                break;

            case DCMD:

                s->chan[channel].cmd = value;

                break;

            default:

                goto fail;

            }

            break;

        }

    fail:

        hw_error("%s: Bad offset " TARGET_FMT_plx "\n", __FUNCTION__, offset);

    }

}

static uint32_t pxa2xx_dma_readbad(void *opaque, target_phys_addr_t offset)

{

    hw_error("%s: Bad access width\n", __FUNCTION__);

    return 5;

}

static void pxa2xx_dma_writebad(void *opaque,

                 target_phys_addr_t offset, uint32_t value)

{

    hw_error("%s: Bad access width\n", __FUNCTION__);

}

static CPUReadMemoryFunc * const pxa2xx_dma_readfn[] = {

    pxa2xx_dma_readbad,

    pxa2xx_dma_readbad,

    pxa2xx_dma_read

};

static CPUWriteMemoryFunc * const pxa2xx_dma_writefn[] = {

    pxa2xx_dma_writebad,

    pxa2xx_dma_writebad,

    pxa2xx_dma_write

};

static void pxa2xx_dma_save(QEMUFile *f, void *opaque)

{

    PXA2xxDMAState *s = (PXA2xxDMAState *) opaque;

    int i;

    qemu_put_be32(f, s->channels);

    qemu_put_be32s(f, &s->stopintr);

    qemu_put_be32s(f, &s->eorintr);

    qemu_put_be32s(f, &s->rasintr);

    qemu_put_be32s(f, &s->startintr);

    qemu_put_be32s(f, &s->endintr);

    qemu_put_be32s(f, &s->align);

    qemu_put_be32s(f, &s->pio);

    qemu_put_buffer(f, s->req, PXA2XX_DMA_NUM_REQUESTS);

    for (i = 0; i < s->channels; i ++) {

        qemu_put_betl(f, s->chan[i].descr);

        qemu_put_betl(f, s->chan[i].src);

        qemu_put_betl(f, s->chan[i].dest);

        qemu_put_be32s(f, &s->chan[i].cmd);

        qemu_put_be32s(f, &s->chan[i].state);

        qemu_put_be32(f, s->chan[i].request);

    };

}

static int pxa2xx_dma_load(QEMUFile *f, void *opaque, int version_id)

{

    PXA2xxDMAState *s = (PXA2xxDMAState *) opaque;

    int i;

    if (qemu_get_be32(f) != s->channels)

        return -EINVAL;

    qemu_get_be32s(f, &s->stopintr);

    qemu_get_be32s(f, &s->eorintr);

    qemu_get_be32s(f, &s->rasintr);

    qemu_get_be32s(f, &s->startintr);

    qemu_get_be32s(f, &s->endintr);

    qemu_get_be32s(f, &s->align);

    qemu_get_be32s(f, &s->pio);

    qemu_get_buffer(f, s->req, PXA2XX_DMA_NUM_REQUESTS);

    for (i = 0; i < s->channels; i ++) {

        s->chan[i].descr = qemu_get_betl(f);

        s->chan[i].src = qemu_get_betl(f);

        s->chan[i].dest = qemu_get_betl(f);

        qemu_get_be32s(f, &s->chan[i].cmd);

        qemu_get_be32s(f, &s->chan[i].state);

        s->chan[i].request = qemu_get_be32(f);

    };

    return 0;

}

static PXA2xxDMAState *pxa2xx_dma_init(target_phys_addr_t base,

                qemu_irq irq, int channels)

{

    int i, iomemtype;

    PXA2xxDMAState *s;

    s = (PXA2xxDMAState *)

            qemu_mallocz(sizeof(PXA2xxDMAState));

    s->channels = channels;

    s->chan = qemu_mallocz(sizeof(PXA2xxDMAChannel) * s->channels);

    s->irq = irq;

    s->handler = (pxa2xx_dma_handler_t) pxa2xx_dma_request;

    s->req = qemu_mallocz(sizeof(uint8_t) * PXA2XX_DMA_NUM_REQUESTS);

    memset(s->chan, 0, sizeof(PXA2xxDMAChannel) * s->channels);

    for (i = 0; i < s->channels; i ++)

        s->chan[i].state = DCSR_STOPINTR;

    memset(s->req, 0, sizeof(uint8_t) * PXA2XX_DMA_NUM_REQUESTS);

    iomemtype = cpu_register_io_memory(pxa2xx_dma_readfn,

                    pxa2xx_dma_writefn, s);

    cpu_register_physical_memory(base, 0x00010000, iomemtype);

    register_savevm("pxa2xx_dma", 0, 0, pxa2xx_dma_save, pxa2xx_dma_load, s);

    return s;

}

PXA2xxDMAState *pxa27x_dma_init(target_phys_addr_t base,

                qemu_irq irq)

{

    return pxa2xx_dma_init(base, irq, PXA27X_DMA_NUM_CHANNELS);

}

PXA2xxDMAState *pxa255_dma_init(target_phys_addr_t base,

                qemu_irq irq)

{

    return pxa2xx_dma_init(base, irq, PXA255_DMA_NUM_CHANNELS);

}

void pxa2xx_dma_request(PXA2xxDMAState *s, int req_num, int on)

{

    int ch;

    if (req_num < 0 || req_num >= PXA2XX_DMA_NUM_REQUESTS)

        hw_error("%s: Bad DMA request %i\n", __FUNCTION__, req_num);

    if (!(s->req[req_num] & DRCMR_MAPVLD))

        return;

    ch = s->req[req_num] & DRCMR_CHLNUM;

    if (!s->chan[ch].request && on)

        s->chan[ch].state |= DCSR_RASINTR;

    else

        s->chan[ch].state &= ~DCSR_RASINTR;

    if (s->chan[ch].request && !on)

        s->chan[ch].state |= DCSR_EORINT;

    s->chan[ch].request = on;

    if (on) {

        pxa2xx_dma_run(s);

        pxa2xx_dma_update(s, ch);

    }

}