gwj / at91sam9263 · Files

/*

 * QEMU ESP/NCR53C9x emulation

 *

 * Copyright (c) 2005-2006 Fabrice Bellard

 *

 * 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 "hw.h"
#include "scsi-disk.h"

#include "scsi.h"

/* debug ESP card */

//#define DEBUG_ESP

/*

 * On Sparc32, this is the ESP (NCR53C90) part of chip STP2000 (Master I/O),
 * also produced as NCR89C100. See

 * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C100.txt
 * and
 * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR53C9X.txt
 */

#ifdef DEBUG_ESP
#define DPRINTF(fmt, args...) \
do { printf("ESP: " fmt , ##args); } while (0)
#else

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

#endif

#define ESP_REGS 16

#define TI_BUFSZ 32

typedef struct ESPState ESPState;

struct ESPState {

    uint32_t it_shift;

    qemu_irq irq;

    uint8_t rregs[ESP_REGS];
    uint8_t wregs[ESP_REGS];

    int32_t ti_size;

    uint32_t ti_rptr, ti_wptr;
    uint8_t ti_buf[TI_BUFSZ];

    uint32_t sense;
    uint32_t dma;

    SCSIDevice *scsi_dev[ESP_MAX_DEVS];

    SCSIDevice *current_dev;

    uint8_t cmdbuf[TI_BUFSZ];

    uint32_t cmdlen;
    uint32_t do_cmd;

    /* The amount of data left in the current DMA transfer.  */

    uint32_t dma_left;

    /* The size of the current DMA transfer.  Zero if no transfer is in
       progress.  */
    uint32_t dma_counter;

    uint8_t *async_buf;

    uint32_t async_len;

    espdma_memory_read_write dma_memory_read;
    espdma_memory_read_write dma_memory_write;

    void *dma_opaque;

};

#define ESP_TCLO   0x0
#define ESP_TCMID  0x1
#define ESP_FIFO   0x2
#define ESP_CMD    0x3
#define ESP_RSTAT  0x4
#define ESP_WBUSID 0x4
#define ESP_RINTR  0x5
#define ESP_WSEL   0x5
#define ESP_RSEQ   0x6
#define ESP_WSYNTP 0x6
#define ESP_RFLAGS 0x7
#define ESP_WSYNO  0x7
#define ESP_CFG1   0x8
#define ESP_RRES1  0x9
#define ESP_WCCF   0x9
#define ESP_RRES2  0xa
#define ESP_WTEST  0xa
#define ESP_CFG2   0xb
#define ESP_CFG3   0xc
#define ESP_RES3   0xd
#define ESP_TCHI   0xe
#define ESP_RES4   0xf

#define CMD_DMA 0x80
#define CMD_CMD 0x7f

#define CMD_NOP      0x00
#define CMD_FLUSH    0x01
#define CMD_RESET    0x02
#define CMD_BUSRESET 0x03
#define CMD_TI       0x10
#define CMD_ICCS     0x11
#define CMD_MSGACC   0x12
#define CMD_SATN     0x1a
#define CMD_SELATN   0x42
#define CMD_SELATNS  0x43
#define CMD_ENSEL    0x44

#define STAT_DO 0x00
#define STAT_DI 0x01
#define STAT_CD 0x02
#define STAT_ST 0x03
#define STAT_MI 0x06
#define STAT_MO 0x07

#define STAT_PIO_MASK 0x06

#define STAT_TC 0x10

#define STAT_PE 0x20
#define STAT_GE 0x40

#define STAT_INT 0x80

#define INTR_FC 0x08
#define INTR_BS 0x10
#define INTR_DC 0x20

#define INTR_RST 0x80

#define SEQ_0 0x0
#define SEQ_CD 0x4

#define CFG1_RESREPT 0x40

#define CFG2_MASK 0x15

#define TCHI_FAS100A 0x4

static void esp_raise_irq(ESPState *s)
{
    if (!(s->rregs[ESP_RSTAT] & STAT_INT)) {
        s->rregs[ESP_RSTAT] |= STAT_INT;
        qemu_irq_raise(s->irq);
    }
}

static void esp_lower_irq(ESPState *s)
{
    if (s->rregs[ESP_RSTAT] & STAT_INT) {
        s->rregs[ESP_RSTAT] &= ~STAT_INT;
        qemu_irq_lower(s->irq);
    }
}

static uint32_t get_cmd(ESPState *s, uint8_t *buf)

{

    uint32_t dmalen;

    int target;

    dmalen = s->rregs[ESP_TCLO] | (s->rregs[ESP_TCMID] << 8);
    target = s->wregs[ESP_WBUSID] & 7;

    DPRINTF("get_cmd: len %d target %d\n", dmalen, target);

    if (s->dma) {

        s->dma_memory_read(s->dma_opaque, buf, dmalen);

    } else {

        buf[0] = 0;
        memcpy(&buf[1], s->ti_buf, dmalen);
        dmalen++;

    }

    s->ti_size = 0;

    s->ti_rptr = 0;
    s->ti_wptr = 0;

    if (s->current_dev) {
        /* Started a new command before the old one finished.  Cancel it.  */

        s->current_dev->cancel_io(s->current_dev, 0);

        s->async_len = 0;
    }

    if (target >= ESP_MAX_DEVS || !s->scsi_dev[target]) {

        // No such drive

        s->rregs[ESP_RSTAT] = 0;

        s->rregs[ESP_RINTR] = INTR_DC;
        s->rregs[ESP_RSEQ] = SEQ_0;

        esp_raise_irq(s);

        return 0;

    }

    s->current_dev = s->scsi_dev[target];

    return dmalen;
}

static void do_cmd(ESPState *s, uint8_t *buf)
{
    int32_t datalen;
    int lun;

    DPRINTF("do_cmd: busid 0x%x\n", buf[0]);
    lun = buf[0] & 7;

    datalen = s->current_dev->send_command(s->current_dev, 0, &buf[1], lun);

    s->ti_size = datalen;
    if (datalen != 0) {

        s->rregs[ESP_RSTAT] = STAT_TC;

        s->dma_left = 0;

        s->dma_counter = 0;

        if (datalen > 0) {

            s->rregs[ESP_RSTAT] |= STAT_DI;

            s->current_dev->read_data(s->current_dev, 0);

        } else {

            s->rregs[ESP_RSTAT] |= STAT_DO;

            s->current_dev->write_data(s->current_dev, 0);

        }

    }

    s->rregs[ESP_RINTR] = INTR_BS | INTR_FC;
    s->rregs[ESP_RSEQ] = SEQ_CD;

    esp_raise_irq(s);

}

static void handle_satn(ESPState *s)
{
    uint8_t buf[32];
    int len;

    len = get_cmd(s, buf);
    if (len)
        do_cmd(s, buf);
}

static void handle_satn_stop(ESPState *s)
{
    s->cmdlen = get_cmd(s, s->cmdbuf);
    if (s->cmdlen) {
        DPRINTF("Set ATN & Stop: cmdlen %d\n", s->cmdlen);
        s->do_cmd = 1;

        s->rregs[ESP_RSTAT] = STAT_TC | STAT_CD;

        s->rregs[ESP_RINTR] = INTR_BS | INTR_FC;
        s->rregs[ESP_RSEQ] = SEQ_CD;

        esp_raise_irq(s);

    }
}

static void write_response(ESPState *s)

{

    DPRINTF("Transfer status (sense=%d)\n", s->sense);
    s->ti_buf[0] = s->sense;
    s->ti_buf[1] = 0;

    if (s->dma) {

        s->dma_memory_write(s->dma_opaque, s->ti_buf, 2);

        s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;

        s->rregs[ESP_RINTR] = INTR_BS | INTR_FC;
        s->rregs[ESP_RSEQ] = SEQ_CD;

    } else {

        s->ti_size = 2;
        s->ti_rptr = 0;
        s->ti_wptr = 0;

        s->rregs[ESP_RFLAGS] = 2;

    }

    esp_raise_irq(s);

}

static void esp_dma_done(ESPState *s)
{

    s->rregs[ESP_RSTAT] |= STAT_TC;

    s->rregs[ESP_RINTR] = INTR_BS;
    s->rregs[ESP_RSEQ] = 0;
    s->rregs[ESP_RFLAGS] = 0;
    s->rregs[ESP_TCLO] = 0;
    s->rregs[ESP_TCMID] = 0;

    esp_raise_irq(s);

}

static void esp_do_dma(ESPState *s)
{

    uint32_t len;

    int to_device;

    to_device = (s->ti_size < 0);

    len = s->dma_left;

    if (s->do_cmd) {
        DPRINTF("command len %d + %d\n", s->cmdlen, len);

        s->dma_memory_read(s->dma_opaque, &s->cmdbuf[s->cmdlen], len);

        s->ti_size = 0;
        s->cmdlen = 0;
        s->do_cmd = 0;
        do_cmd(s, s->cmdbuf);
        return;

    }
    if (s->async_len == 0) {
        /* Defer until data is available.  */
        return;
    }
    if (len > s->async_len) {
        len = s->async_len;
    }
    if (to_device) {

        s->dma_memory_read(s->dma_opaque, s->async_buf, len);

    } else {

        s->dma_memory_write(s->dma_opaque, s->async_buf, len);

    }
    s->dma_left -= len;
    s->async_buf += len;
    s->async_len -= len;

    if (to_device)
        s->ti_size += len;
    else
        s->ti_size -= len;

    if (s->async_len == 0) {

        if (to_device) {

            // ti_size is negative

            s->current_dev->write_data(s->current_dev, 0);

        } else {

            s->current_dev->read_data(s->current_dev, 0);

            /* If there is still data to be read from the device then
               complete the DMA operation immeriately.  Otherwise defer
               until the scsi layer has completed.  */
            if (s->dma_left == 0 && s->ti_size > 0) {
                esp_dma_done(s);
            }

        }

    } else {
        /* Partially filled a scsi buffer. Complete immediately.  */

        esp_dma_done(s);
    }

}

static void esp_command_complete(void *opaque, int reason, uint32_t tag,
                                 uint32_t arg)

{
    ESPState *s = (ESPState *)opaque;

    if (reason == SCSI_REASON_DONE) {
        DPRINTF("SCSI Command complete\n");
        if (s->ti_size != 0)
            DPRINTF("SCSI command completed unexpectedly\n");
        s->ti_size = 0;

        s->dma_left = 0;
        s->async_len = 0;
        if (arg)

            DPRINTF("Command failed\n");

        s->sense = arg;

        s->rregs[ESP_RSTAT] = STAT_ST;

        esp_dma_done(s);
        s->current_dev = NULL;

    } else {
        DPRINTF("transfer %d/%d\n", s->dma_left, s->ti_size);

        s->async_len = arg;

        s->async_buf = s->current_dev->get_buf(s->current_dev, 0);

        if (s->dma_left) {

            esp_do_dma(s);

        } else if (s->dma_counter != 0 && s->ti_size <= 0) {
            /* If this was the last part of a DMA transfer then the
               completion interrupt is deferred to here.  */
            esp_dma_done(s);
        }

    }

}

static void handle_ti(ESPState *s)
{

    uint32_t dmalen, minlen;

    dmalen = s->rregs[ESP_TCLO] | (s->rregs[ESP_TCMID] << 8);

    if (dmalen==0) {
      dmalen=0x10000;
    }

    s->dma_counter = dmalen;

    if (s->do_cmd)
        minlen = (dmalen < 32) ? dmalen : 32;

    else if (s->ti_size < 0)
        minlen = (dmalen < -s->ti_size) ? dmalen : -s->ti_size;

    else
        minlen = (dmalen < s->ti_size) ? dmalen : s->ti_size;

    DPRINTF("Transfer Information len %d\n", minlen);

    if (s->dma) {

        s->dma_left = minlen;

        s->rregs[ESP_RSTAT] &= ~STAT_TC;

        esp_do_dma(s);

    } else if (s->do_cmd) {
        DPRINTF("command len %d\n", s->cmdlen);
        s->ti_size = 0;
        s->cmdlen = 0;
        s->do_cmd = 0;
        do_cmd(s, s->cmdbuf);
        return;
    }

}

static void esp_reset(void *opaque)

{
    ESPState *s = opaque;

    esp_lower_irq(s);

    memset(s->rregs, 0, ESP_REGS);
    memset(s->wregs, 0, ESP_REGS);

    s->rregs[ESP_TCHI] = TCHI_FAS100A; // Indicate fas100a

    s->ti_size = 0;
    s->ti_rptr = 0;
    s->ti_wptr = 0;
    s->dma = 0;

    s->do_cmd = 0;

}

static void parent_esp_reset(void *opaque, int irq, int level)
{
    if (level)
        esp_reset(opaque);
}

static uint32_t esp_mem_readb(void *opaque, target_phys_addr_t addr)
{
    ESPState *s = opaque;
    uint32_t saddr;

    saddr = (addr >> s->it_shift) & (ESP_REGS - 1);

    DPRINTF("read reg[%d]: 0x%2.2x\n", saddr, s->rregs[saddr]);

    switch (saddr) {

    case ESP_FIFO:

        if (s->ti_size > 0) {
            s->ti_size--;

            if ((s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {

                /* Data in/out.  */

                fprintf(stderr, "esp: PIO data read not implemented\n");

                s->rregs[ESP_FIFO] = 0;

            } else {

                s->rregs[ESP_FIFO] = s->ti_buf[s->ti_rptr++];

            }

            esp_raise_irq(s);

        }
        if (s->ti_size == 0) {

            s->ti_rptr = 0;
            s->ti_wptr = 0;
        }

        break;

    case ESP_RINTR:

        // Clear interrupt/error status bits

        s->rregs[ESP_RSTAT] &= ~(STAT_GE | STAT_PE);
        esp_lower_irq(s);

        break;

    default:

        break;

    }

    return s->rregs[saddr];

}

static void esp_mem_writeb(void *opaque, target_phys_addr_t addr, uint32_t val)
{
    ESPState *s = opaque;
    uint32_t saddr;

    saddr = (addr >> s->it_shift) & (ESP_REGS - 1);

    DPRINTF("write reg[%d]: 0x%2.2x -> 0x%2.2x\n", saddr, s->wregs[saddr],
            val);

    switch (saddr) {

    case ESP_TCLO:
    case ESP_TCMID:
        s->rregs[ESP_RSTAT] &= ~STAT_TC;

        break;

    case ESP_FIFO:

        if (s->do_cmd) {
            s->cmdbuf[s->cmdlen++] = val & 0xff;

        } else if ((s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {

            uint8_t buf;
            buf = val & 0xff;
            s->ti_size--;

            fprintf(stderr, "esp: PIO data write not implemented\n");

        } else {
            s->ti_size++;
            s->ti_buf[s->ti_wptr++] = val & 0xff;
        }

        break;

    case ESP_CMD:

        s->rregs[saddr] = val;

        if (val & CMD_DMA) {

            s->dma = 1;

            /* Reload DMA counter.  */

            s->rregs[ESP_TCLO] = s->wregs[ESP_TCLO];
            s->rregs[ESP_TCMID] = s->wregs[ESP_TCMID];

        } else {
            s->dma = 0;
        }

        switch(val & CMD_CMD) {
        case CMD_NOP:

            DPRINTF("NOP (%2.2x)\n", val);
            break;

        case CMD_FLUSH:

            DPRINTF("Flush FIFO (%2.2x)\n", val);

            //s->ti_size = 0;

            s->rregs[ESP_RINTR] = INTR_FC;
            s->rregs[ESP_RSEQ] = 0;

            break;

        case CMD_RESET:

            DPRINTF("Chip reset (%2.2x)\n", val);
            esp_reset(s);
            break;

        case CMD_BUSRESET:

            DPRINTF("Bus reset (%2.2x)\n", val);

            s->rregs[ESP_RINTR] = INTR_RST;
            if (!(s->wregs[ESP_CFG1] & CFG1_RESREPT)) {

                esp_raise_irq(s);

            }

            break;

        case CMD_TI:

            handle_ti(s);
            break;

        case CMD_ICCS:

            DPRINTF("Initiator Command Complete Sequence (%2.2x)\n", val);
            write_response(s);
            break;

        case CMD_MSGACC:

            DPRINTF("Message Accepted (%2.2x)\n", val);
            write_response(s);

            s->rregs[ESP_RINTR] = INTR_DC;
            s->rregs[ESP_RSEQ] = 0;

            break;

        case CMD_SATN:

            DPRINTF("Set ATN (%2.2x)\n", val);
            break;

        case CMD_SELATN:

            DPRINTF("Set ATN (%2.2x)\n", val);
            handle_satn(s);
            break;

        case CMD_SELATNS:

            DPRINTF("Set ATN & stop (%2.2x)\n", val);
            handle_satn_stop(s);
            break;

        case CMD_ENSEL:

            DPRINTF("Enable selection (%2.2x)\n", val);
            break;

        default:
            DPRINTF("Unhandled ESP command (%2.2x)\n", val);
            break;
        }
        break;

    case ESP_WBUSID ... ESP_WSYNO:

        break;

    case ESP_CFG1:

        s->rregs[saddr] = val;
        break;

    case ESP_WCCF ... ESP_WTEST:

        break;