text: /*	$NetBSD: atapi_wdc.c,v 1.20.2.2 1999/05/05 22:39:04 perry Exp $	*/
  
  /*
   * Copyright (c) 1998 Manuel Bouyer.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   */
  
  #ifndef WDCDEBUG
  #define WDCDEBUG
  #endif /* WDCDEBUG */
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/kernel.h>
  #include <sys/file.h>
  #include <sys/stat.h>
  #include <sys/buf.h>
  #include <sys/malloc.h>
  #include <sys/device.h>
  #include <sys/syslog.h>
  #include <sys/proc.h>
  
  #include <vm/vm.h>
  
  #include <machine/intr.h>
  #include <machine/bus.h>
  
  #ifndef __BUS_SPACE_HAS_STREAM_METHODS
  #define    bus_space_write_multi_stream_2    bus_space_write_multi_2
  #define    bus_space_write_multi_stream_4    bus_space_write_multi_4
  #define    bus_space_read_multi_stream_2    bus_space_read_multi_2
  #define    bus_space_read_multi_stream_4    bus_space_read_multi_4
  #endif /* __BUS_SPACE_HAS_STREAM_METHODS */
  
  #include <dev/ata/atareg.h>
  #include <dev/ata/atavar.h>
  #include <dev/ic/wdcreg.h>
  #include <dev/ic/wdcvar.h>
  #include <dev/scsipi/scsipi_all.h>
  #include <dev/scsipi/scsipiconf.h>
  #include <dev/scsipi/atapiconf.h>
  
  #define DEBUG_INTR   0x01
  #define DEBUG_XFERS  0x02
  #define DEBUG_STATUS 0x04
  #define DEBUG_FUNCS  0x08
  #define DEBUG_PROBE  0x10
  #ifdef WDCDEBUG
  int wdcdebug_atapi_mask = 0;
  #define WDCDEBUG_PRINT(args, level) \
  	if (wdcdebug_atapi_mask & (level)) \
  		printf args
  #else
  #define WDCDEBUG_PRINT(args, level)
  #endif
  
  #define ATAPI_DELAY 10	/* 10 ms, this is used only before sending a cmd */
  
  void  wdc_atapi_minphys  __P((struct buf *bp));
  void  wdc_atapi_start	__P((struct channel_softc *,struct wdc_xfer *));
  int   wdc_atapi_intr	 __P((struct channel_softc *, struct wdc_xfer *, int));
  int   wdc_atapi_ctrl	 __P((struct channel_softc *, struct wdc_xfer *, int));
  void  wdc_atapi_done	 __P((struct channel_softc *, struct wdc_xfer *));
  void  wdc_atapi_reset	 __P((struct channel_softc *, struct wdc_xfer *));
  int   wdc_atapi_send_cmd __P((struct scsipi_xfer *sc_xfer));
  
  #define MAX_SIZE MAXPHYS
  
  void
  wdc_atapibus_attach(chp)
  	struct channel_softc *chp;
  {
  	struct wdc_softc *wdc = chp->wdc;
  	int channel = chp->channel;
  	struct ata_atapi_attach aa_link;
  
  	/*
  	 * Fill in the adapter.
  	 */
  	wdc->sc_atapi_adapter.scsipi_cmd = wdc_atapi_send_cmd;
  	wdc->sc_atapi_adapter.scsipi_minphys = wdc_atapi_minphys;
  
  	memset(&aa_link, 0, sizeof(struct ata_atapi_attach));
  	aa_link.aa_type = T_ATAPI;
  	aa_link.aa_channel = channel;
  	aa_link.aa_openings = 1;
  	aa_link.aa_drv_data = chp->ch_drive; /* pass the whole array */
  	aa_link.aa_bus_private = &wdc->sc_atapi_adapter;
  	(void)config_found(&wdc->sc_dev, (void *)&aa_link, atapi_print);
  }
  
  void
  wdc_atapi_minphys (struct buf *bp)
  {
  	if(bp->b_bcount > MAX_SIZE)
  		bp->b_bcount = MAX_SIZE;
  	minphys(bp);
  }
  
  int
  wdc_atapi_get_params(ab_link, drive, flags, id)
  	struct scsipi_link *ab_link;
  	u_int8_t drive;
  	int flags;
  	struct ataparams *id;
  {
  	struct wdc_softc *wdc = (void*)ab_link->adapter_softc;
  	struct channel_softc *chp =
  	    wdc->channels[ab_link->scsipi_atapi.channel];
  	struct wdc_command wdc_c;
  
  	/* if no ATAPI device detected at wdc attach time, skip */
  	/*
  	 * XXX this will break scsireprobe if this is of any interest for
  	 * ATAPI devices one day.
  	 */
  	if ((chp->ch_drive[drive].drive_flags & DRIVE_ATAPI) == 0) {
  		WDCDEBUG_PRINT(("wdc_atapi_get_params: drive %d not present\n",
  		    drive), DEBUG_PROBE);
  		return -1;
  	}
  	memset(&wdc_c, 0, sizeof(struct wdc_command));
  	wdc_c.r_command = ATAPI_SOFT_RESET;
  	wdc_c.r_st_bmask = 0;
  	wdc_c.r_st_pmask = 0;
  	wdc_c.flags = AT_POLL;
  	wdc_c.timeout = WDC_RESET_WAIT;
  	if (wdc_exec_command(&chp->ch_drive[drive], &wdc_c) != WDC_COMPLETE) {
  		printf("wdc_atapi_get_params: ATAPI_SOFT_RESET failed for"
  		    " drive %s:%d:%d: driver failed\n",
  		    chp->wdc->sc_dev.dv_xname, chp->channel, drive);
  		panic("wdc_atapi_get_params");
  	}
  	if (wdc_c.flags & (AT_ERROR | AT_TIMEOU | AT_DF)) {
  		WDCDEBUG_PRINT(("wdc_atapi_get_params: ATAPI_SOFT_RESET "
  		    "failed for drive %s:%d:%d: error 0x%x\n",
  		    chp->wdc->sc_dev.dv_xname, chp->channel, drive, 
  		    wdc_c.r_error), DEBUG_PROBE);
  		return -1;
  	}
  	chp->ch_drive[drive].state = 0;
  
  	bus_space_read_1(chp->cmd_iot, chp->cmd_ioh, wd_status);
  	
  	/* Some ATAPI devices need a bit more time after software reset. */
  	delay(5000);
  	if (ata_get_params(&chp->ch_drive[drive], AT_POLL, id) != 0) {
  		WDCDEBUG_PRINT(("wdc_atapi_get_params: ATAPI_IDENTIFY_DEVICE "
  		    "failed for drive %s:%d:%d: error 0x%x\n",
  		    chp->wdc->sc_dev.dv_xname, chp->channel, drive, 
  		    wdc_c.r_error), DEBUG_PROBE);
  		return -1;
  	}
  	return COMPLETE;
  }
  
  int
  wdc_atapi_send_cmd(sc_xfer)
  	struct scsipi_xfer *sc_xfer;
  {
  	struct wdc_softc *wdc = (void*)sc_xfer->sc_link->adapter_softc;
  	struct wdc_xfer *xfer;
  	int flags = sc_xfer->flags;
  	int channel = sc_xfer->sc_link->scsipi_atapi.channel;
  	int drive = sc_xfer->sc_link->scsipi_atapi.drive;
  	int s, ret;
  
  	WDCDEBUG_PRINT(("wdc_atapi_send_cmd %s:%d:%d\n",
  	    wdc->sc_dev.dv_xname, channel, drive), DEBUG_XFERS);
  
  	xfer = wdc_get_xfer(flags & SCSI_NOSLEEP ? WDC_NOSLEEP : WDC_CANSLEEP);
  	if (xfer == NULL) {
  		return TRY_AGAIN_LATER;
  	}
  	if (sc_xfer->flags & SCSI_POLL)
  		xfer->c_flags |= C_POLL;
  	xfer->drive = drive;
  	xfer->c_flags |= C_ATAPI;
  	xfer->cmd = sc_xfer;
  	xfer->databuf = sc_xfer->data;
  	xfer->c_bcount = sc_xfer->datalen;
  	xfer->c_start = wdc_atapi_start;
  	xfer->c_intr = wdc_atapi_intr;
  	s = splbio();
  	wdc_exec_xfer(wdc->channels[channel], xfer);
  #ifdef DIAGNOSTIC
  	if ((sc_xfer->flags & SCSI_POLL) != 0 &&
  	    (sc_xfer->flags & ITSDONE) == 0)
  		panic("wdc_atapi_send_cmd: polled command not done");
  #endif
  	ret = (sc_xfer->flags & ITSDONE) ? COMPLETE : SUCCESSFULLY_QUEUED;
  	splx(s);
  	return ret;
  }
  
  void
  wdc_atapi_start(chp, xfer)
  	struct channel_softc *chp;
  	struct wdc_xfer *xfer;
  {
  	struct scsipi_xfer *sc_xfer = xfer->cmd;
  	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
  
  	WDCDEBUG_PRINT(("wdc_atapi_start %s:%d:%d, scsi flags 0x%x \n",
  	    chp->wdc->sc_dev.dv_xname, chp->channel, drvp->drive,
  	    sc_xfer->flags), DEBUG_XFERS);
  	/* Adjust C_DMA, it may have changed if we are requesting sense */
  	if ((drvp->drive_flags & (DRIVE_DMA | DRIVE_UDMA)) &&
  	    (sc_xfer->datalen > 0 || (xfer->c_flags & C_SENSE)))
  		xfer->c_flags |= C_DMA;
  	else
  		xfer->c_flags &= ~C_DMA;
  	/* Do control operations specially. */
  	if (drvp->state < READY) {
  		if (drvp->state != PIOMODE) {
  			printf("%s:%d:%d: bad state %d in wdc_atapi_start\n",
  			    chp->wdc->sc_dev.dv_xname, chp->channel,
  			    xfer->drive, drvp->state);
  			panic("wdc_atapi_start: bad state");
  		}
  		wdc_atapi_ctrl(chp, xfer, 0);
  		return;
  	}
  	bus_space_write_1(chp->cmd_iot, chp->cmd_ioh, wd_sdh,
  	    WDSD_IBM | (xfer->drive << 4));
  	if (wait_for_unbusy(chp, ATAPI_DELAY) < 0) {
  		printf("wdc_atapi_start: not ready, st = %02x\n",
  		    chp->ch_status);
  		sc_xfer->error = XS_TIMEOUT;
  		wdc_atapi_reset(chp, xfer);
  		return;
  	}
  
  	/*
  	 * Even with WDCS_ERR, the device should accept a command packet
  	 * Limit length to what can be stuffed into the cylinder register
  	 * (16 bits).  Some CD-ROMs seem to interpret '0' as 65536,
  	 * but not all devices do that and it's not obvious from the
  	 * ATAPI spec that that behaviour should be expected.  If more
  	 * data is necessary, multiple data transfer phases will be done.
  	 */
  
  	wdccommand(chp, xfer->drive, ATAPI_PKT_CMD, 
  	    sc_xfer->datalen <= 0xffff ? sc_xfer->datalen : 0xffff,
  	    0, 0, 0, 
  	    (xfer->c_flags & C_DMA) ? ATAPI_PKT_CMD_FTRE_DMA : 0);
  	
  	/*
  	 * If there is no interrupt for CMD input, busy-wait for it (done in 
  	 * the interrupt routine. If it is a polled command, call the interrupt
  	 * routine until command is done.
  	 */
  	if ((sc_xfer->sc_link->scsipi_atapi.cap  & ATAPI_CFG_DRQ_MASK) !=
  	    ATAPI_CFG_IRQ_DRQ || (sc_xfer->flags & SCSI_POLL)) {
  		/* Wait for at last 400ns for status bit to be valid */
  		DELAY(1);
  		wdc_atapi_intr(chp, xfer, 0);
  	} else {
  		chp->ch_flags |= WDCF_IRQ_WAIT;
  		timeout(wdctimeout, chp, hz);
  	}
  	if (sc_xfer->flags & SCSI_POLL) {
  		while ((sc_xfer->flags & ITSDONE) == 0) {
  			/* Wait for at last 400ns for status bit to be valid */
  			DELAY(1);
  			wdc_atapi_intr(chp, xfer, 0);
  		}
  	}
  }
  
  int
  wdc_atapi_intr(chp, xfer, irq)
  	struct channel_softc *chp;
  	struct wdc_xfer *xfer;
  	int irq;
  {
  	struct scsipi_xfer *sc_xfer = xfer->cmd;
  	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
  	int len, phase, i, retries=0;
  	int ire, dma_err = 0;
  	int dma_flags = 0;
  	struct scsipi_generic _cmd_reqsense;
  	struct scsipi_sense *cmd_reqsense =
  	    (struct scsipi_sense *)&_cmd_reqsense;
  	void *cmd;
  
  	WDCDEBUG_PRINT(("wdc_atapi_intr %s:%d:%d\n",
  	    chp->wdc->sc_dev.dv_xname, chp->channel, drvp->drive), DEBUG_INTR);
  
  	/* Is it not a transfer, but a control operation? */
  	if (drvp->state < READY) {
  		printf("%s:%d:%d: bad state %d in wdc_atapi_intr\n",
  		    chp->wdc->sc_dev.dv_xname, chp->channel, xfer->drive,
  		    drvp->state);
  		panic("wdc_atapi_intr: bad state\n");
  	}
  	/* Ack interrupt done in wait_for_unbusy */
  	bus_space_write_1(chp->cmd_iot, chp->cmd_ioh, wd_sdh,
  	    WDSD_IBM | (xfer->drive << 4));
  	if (wait_for_unbusy(chp,
  	    (irq == 0) ? sc_xfer->timeout : 0) != 0) {
  		if (irq && (xfer->c_flags & C_TIMEOU) == 0)
  			return 0; /* IRQ was not for us */
  		printf("%s:%d:%d: device timeout, c_bcount=%d, c_skip=%d\n",
  		    chp->wdc->sc_dev.dv_xname, chp->channel, xfer->drive,
  		    xfer->c_bcount, xfer->c_skip);
  		if (xfer->c_flags & C_DMA)
  			drvp->n_dmaerrs++;
  		sc_xfer->error = XS_TIMEOUT;
  		wdc_atapi_reset(chp, xfer);
  		return 1;
  	}
  	/* If we missed an IRQ and were using DMA, flag it as a DMA error */
  	if ((xfer->c_flags & C_TIMEOU) && (xfer->c_flags & C_DMA))
  		drvp->n_dmaerrs++;
  	/* 
  	 * if the request sense command was aborted, report the short sense
  	 * previously recorded, else continue normal processing
  	 */
  
  	if ((xfer->c_flags & C_SENSE) != 0 &&
  	    (chp->ch_status & WDCS_ERR) != 0 &&
  	    (chp->ch_error & WDCE_ABRT) != 0) {
  		WDCDEBUG_PRINT(("wdc_atapi_intr: request_sense aborted, "
  		    "calling wdc_atapi_done(), sense 0x%x\n",
  		    sc_xfer->sense.atapi_sense), DEBUG_INTR);
  		wdc_atapi_done(chp, xfer);
  		return 1;
  	}
  
  	if (xfer->c_flags & C_DMA) {
  		dma_flags = ((sc_xfer->flags & SCSI_DATA_IN) ||
  		    (xfer->c_flags & C_SENSE)) ?  WDC_DMA_READ : 0;
  		dma_flags |= sc_xfer->flags & SCSI_POLL ? WDC_DMA_POLL : 0;
  	}
  again:
  	len = bus_space_read_1(chp->cmd_iot, chp->cmd_ioh, wd_cyl_lo) +
  	    256 * bus_space_read_1(chp->cmd_iot, chp->cmd_ioh, wd_cyl_hi);
  	ire = bus_space_read_1(chp->cmd_iot, chp->cmd_ioh, wd_ireason);
  	phase = (ire & (WDCI_CMD | WDCI_IN)) | (chp->ch_status & WDCS_DRQ);
  	WDCDEBUG_PRINT(("wdc_atapi_intr: c_bcount %d len %d st 0x%x err 0x%x "
  	    "ire 0x%x :", xfer->c_bcount,
  	    len, chp->ch_status, chp->ch_error, ire), DEBUG_INTR);
  
  	switch (phase) {
  	case PHASE_CMDOUT:
  		if (xfer->c_flags & C_SENSE) {
  			memset(cmd_reqsense, 0, sizeof(struct scsipi_generic));
  			cmd_reqsense->opcode = REQUEST_SENSE;
  			cmd_reqsense->length = xfer->c_bcount;
  			cmd = cmd_reqsense;
  		} else {
  			cmd  = sc_xfer->cmd;
  		}
  		WDCDEBUG_PRINT(("PHASE_CMDOUT\n"), DEBUG_INTR);
  		/* Init the DMA channel if necessary */
  		if (xfer->c_flags & C_DMA) {
  			if ((*chp->wdc->dma_init)(chp->wdc->dma_arg,
  			    chp->channel, xfer->drive,
  			    xfer->databuf, xfer->c_bcount, dma_flags) != 0) {
  				sc_xfer->error = XS_DRIVER_STUFFUP;
  				break;
  			}
  		}
  		/* send packet command */
  		/* Commands are 12 or 16 bytes long. It's 32-bit aligned */
  		if ((chp->wdc->cap & WDC_CAPABILITY_ATAPI_NOSTREAM)) {
  			if (drvp->drive_flags & DRIVE_CAP32) {
  				bus_space_write_multi_4(chp->data32iot,
  				    chp->data32ioh, 0,
  				    (u_int32_t *)cmd,
  				    sc_xfer->cmdlen >> 2);
  			} else {
  				bus_space_write_multi_2(chp->cmd_iot,
  				    chp->cmd_ioh, wd_data,
  				    (u_int16_t *)cmd,
  				    sc_xfer->cmdlen >> 1);
  			}
  		} else {
  			if (drvp->drive_flags & DRIVE_CAP32) {
  				bus_space_write_multi_stream_4(chp->data32iot,
  				    chp->data32ioh, 0,
  				    (u_int32_t *)cmd,
  				    sc_xfer->cmdlen >> 2);
  			} else {
  				bus_space_write_multi_stream_2(chp->cmd_iot,
  				    chp->cmd_ioh, wd_data,
  				    (u_int16_t *)cmd,
  				    sc_xfer->cmdlen >> 1);
  			}
  		}
  		/* Start the DMA channel if necessary */
  		if (xfer->c_flags & C_DMA) {
  			(*chp->wdc->dma_start)(chp->wdc->dma_arg,
  			    chp->channel, xfer->drive, dma_flags);
  		}
  
  		if ((sc_xfer->flags & SCSI_POLL) == 0) {
  			chp->ch_flags |= WDCF_IRQ_WAIT;
  			timeout(wdctimeout, chp, sc_xfer->timeout * hz / 1000);
  		}
  		return 1;
  
  	 case PHASE_DATAOUT:
  		/* write data */
  		WDCDEBUG_PRINT(("PHASE_DATAOUT\n"), DEBUG_INTR);
  		if ((sc_xfer->flags & SCSI_DATA_OUT) == 0 ||
  		    (xfer->c_flags & C_DMA) != 0) {
  			printf("wdc_atapi_intr: bad data phase DATAOUT\n");
  			if (xfer->c_flags & C_DMA) {
  				(*chp->wdc->dma_finish)(chp->wdc->dma_arg,
  				    chp->channel, xfer->drive, dma_flags);
  				drvp->n_dmaerrs++;
  			}
  			sc_xfer->error = XS_TIMEOUT;
  			wdc_atapi_reset(chp, xfer);
  			return 1;
  		}
  		if (xfer->c_bcount < len) {
  			printf("wdc_atapi_intr: warning: write only "
  			    "%d of %d requested bytes\n", xfer->c_bcount, len);
  			if ((chp->wdc->cap & WDC_CAPABILITY_ATAPI_NOSTREAM)) {
  				bus_space_write_multi_2(chp->cmd_iot,
  				    chp->cmd_ioh, wd_data,
  				    (u_int16_t *)((char *)xfer->databuf +
  				                  xfer->c_skip),
  				    xfer->c_bcount >> 1);
  			} else {
  				bus_space_write_multi_stream_2(chp->cmd_iot,
  				    chp->cmd_ioh, wd_data,
  				    (u_int16_t *)((char *)xfer->databuf +
  				                  xfer->c_skip),
  				    xfer->c_bcount >> 1);
  			}
  			for (i = xfer->c_bcount; i < len; i += 2)
  				bus_space_write_2(chp->cmd_iot, chp->cmd_ioh,
  				    wd_data, 0);
  			xfer->c_skip += xfer->c_bcount;
  			xfer->c_bcount = 0;
  		} else {
  			if (drvp->drive_flags & DRIVE_CAP32) {
  			    if ((chp->wdc->cap & WDC_CAPABILITY_ATAPI_NOSTREAM))
  				bus_space_write_multi_4(chp->data32iot,
  				    chp->data32ioh, 0,
  				    (u_int32_t *)((char *)xfer->databuf +
  				                  xfer->c_skip),
  				    len >> 2);
  			    else
  				bus_space_write_multi_stream_4(chp->data32iot,
  				    chp->data32ioh, wd_data,
  				    (u_int32_t *)((char *)xfer->databuf +
  				                  xfer->c_skip),
  				    len >> 2);
  
  			    xfer->c_skip += len & 0xfffffffc;
  			    xfer->c_bcount -= len & 0xfffffffc;
  			    len = len & 0x03;
  			}
  			if (len > 0) {
  			    if ((chp->wdc->cap & WDC_CAPABILITY_ATAPI_NOSTREAM))
  				bus_space_write_multi_2(chp->cmd_iot,
  				    chp->cmd_ioh, wd_data,
  				    (u_int16_t *)((char *)xfer->databuf +
  				                  xfer->c_skip),
  				    len >> 1);
  			    else
  				bus_space_write_multi_stream_2(chp->cmd_iot,
  				    chp->cmd_ioh, wd_data,
  				    (u_int16_t *)((char *)xfer->databuf +
  				                  xfer->c_skip),
  				    len >> 1);
  			    xfer->c_skip += len;
  			    xfer->c_bcount -= len;
  			}
  		}
  		if ((sc_xfer->flags & SCSI_POLL) == 0) {
  			chp->ch_flags |= WDCF_IRQ_WAIT;
  			timeout(wdctimeout, chp, sc_xfer->timeout * hz / 1000);
  		}
  		return 1;
  
  	case PHASE_DATAIN:
  		/* Read data */
  		WDCDEBUG_PRINT(("PHASE_DATAIN\n"), DEBUG_INTR);
  		if (((sc_xfer->flags & SCSI_DATA_IN) == 0 &&
  		    (xfer->c_flags & C_SENSE) == 0) || 
  		    (xfer->c_flags & C_DMA) != 0) {
  			printf("wdc_atapi_intr: bad data phase DATAIN\n");
  			if (xfer->c_flags & C_DMA) {
  				(*chp->wdc->dma_finish)(chp->wdc->dma_arg,
  				    chp->channel, xfer->drive, dma_flags);
  				drvp->n_dmaerrs++;
  			}
  			sc_xfer->error = XS_TIMEOUT;
  			wdc_atapi_reset(chp, xfer);
  			return 1;
  		}
  		if (xfer->c_bcount < len) {
  			printf("wdc_atapi_intr: warning: reading only "
  			    "%d of %d bytes\n", xfer->c_bcount, len);
  			if ((chp->wdc->cap & WDC_CAPABILITY_ATAPI_NOSTREAM)) {
  			    bus_space_read_multi_2(chp->cmd_iot,
  			    chp->cmd_ioh, wd_data,
  			    (u_int16_t *)((char *)xfer->databuf +
  			                  xfer->c_skip),
  			    xfer->c_bcount >> 1);
  			} else {
  			    bus_space_read_multi_stream_2(chp->cmd_iot,
  			    chp->cmd_ioh, wd_data,
  			    (u_int16_t *)((char *)xfer->databuf +
  			                  xfer->c_skip),
  			    xfer->c_bcount >> 1);
  			}
  			wdcbit_bucket(chp, len - xfer->c_bcount);
  			xfer->c_skip += xfer->c_bcount;
  			xfer->c_bcount = 0;
  		} else {
  			if (drvp->drive_flags & DRIVE_CAP32) {
  			    if ((chp->wdc->cap & WDC_CAPABILITY_ATAPI_NOSTREAM))
  				bus_space_read_multi_4(chp->data32iot,
  				    chp->data32ioh, 0,
  				    (u_int32_t *)((char *)xfer->databuf +
  				                  xfer->c_skip),
  				    len >> 2);
  			    else
  				bus_space_read_multi_stream_4(chp->data32iot,
  				    chp->data32ioh, wd_data,
  				    (u_int32_t *)((char *)xfer->databuf +
  				                  xfer->c_skip),
  				    len >> 2);
  				
  			    xfer->c_skip += len & 0xfffffffc;
  			    xfer->c_bcount -= len & 0xfffffffc;
  			    len = len & 0x03;
  			}
  			if (len > 0) {
  			    if ((chp->wdc->cap & WDC_CAPABILITY_ATAPI_NOSTREAM))
  				bus_space_read_multi_2(chp->cmd_iot,
  				    chp->cmd_ioh, wd_data,
  				    (u_int16_t *)((char *)xfer->databuf +
  				                  xfer->c_skip), 
  				    len >> 1);
  			    else
  				bus_space_read_multi_stream_2(chp->cmd_iot,
  				    chp->cmd_ioh, wd_data,
  				    (u_int16_t *)((char *)xfer->databuf +
  				                  xfer->c_skip), 
  				    len >> 1);
  			    xfer->c_skip += len;
  			    xfer->c_bcount -=len;
  			}
  		}
  		if ((sc_xfer->flags & SCSI_POLL) == 0) {
  			chp->ch_flags |= WDCF_IRQ_WAIT;
  			timeout(wdctimeout, chp, sc_xfer->timeout * hz / 1000);
  		}
  		return 1;
  
  	case PHASE_ABORTED:
  	case PHASE_COMPLETED:
  		WDCDEBUG_PRINT(("PHASE_COMPLETED\n"), DEBUG_INTR);
  		/* turn off DMA channel */
  		if (xfer->c_flags & C_DMA) {
  			dma_err = (*chp->wdc->dma_finish)(chp->wdc->dma_arg,
  			    chp->channel, xfer->drive, dma_flags);
  			if (xfer->c_flags & C_SENSE)
  				xfer->c_bcount -=
  				    sizeof(sc_xfer->sense.scsi_sense);
  			else
  				xfer->c_bcount -= sc_xfer->datalen;
  		}
  		if (xfer->c_flags & C_SENSE) {
  			if ((chp->ch_status & WDCS_ERR) || dma_err < 0) {
  				/*
  				 * request sense failed ! it's not suppossed
  				 * to be possible
  				 */
  				if (dma_err < 0)
  					drvp->n_dmaerrs++;
  				sc_xfer->error = XS_RESET;
  				wdc_atapi_reset(chp, xfer);
  				return (1);
  			} else if (xfer->c_bcount <
  			    sizeof(sc_xfer->sense.scsi_sense)) {
  				/* use the sense we just read */
  				sc_xfer->error = XS_SENSE;
  			} else {
  				/*
  				 * command completed, but no data was read.
  				 * use the short sense we saved previsouly.
  				 */
  				sc_xfer->error = XS_SHORTSENSE;
  			}
  		} else {
  			sc_xfer->resid = xfer->c_bcount;
  			if (chp->ch_status & WDCS_ERR) {
  				/* save the short sense */
  				sc_xfer->error = XS_SHORTSENSE;
  				sc_xfer->sense.atapi_sense = chp->ch_error;
  				if ((sc_xfer->sc_link->quirks &
  				    ADEV_NOSENSE) == 0) {
  					/*
  					 * let the driver issue a
  					 * 'request sense'
  					 */
  					xfer->databuf = &sc_xfer->sense;
  					xfer->c_bcount =
  					    sizeof(sc_xfer->sense.scsi_sense);
  					xfer->c_skip = 0;
  					xfer->c_flags |= C_SENSE;
  					wdc_atapi_start(chp, xfer);
  					return 1;
  				}
  			} else if (dma_err < 0) {
  				drvp->n_dmaerrs++;
  				sc_xfer->error = XS_RESET;
  				wdc_atapi_reset(chp, xfer);
  				return (1);
  			}
  		}
  		if (xfer->c_bcount != 0) {
  			WDCDEBUG_PRINT(("wdc_atapi_intr: bcount value is "
  			    "%d after io\n", xfer->c_bcount), DEBUG_XFERS);
  		}
  #ifdef DIAGNOSTIC
  		if (xfer->c_bcount < 0) {
  			printf("wdc_atapi_intr warning: bcount value "
  			    "is %d after io\n", xfer->c_bcount);
  		}
  #endif
  		break;
  
  	default:
  		if (++retries<500) {
  			DELAY(100);
  			chp->ch_status = bus_space_read_1(chp->cmd_iot,
  			    chp->cmd_ioh, wd_status);
  			chp->ch_error = bus_space_read_1(chp->cmd_iot,
  			    chp->cmd_ioh, wd_error);
  			goto again;
  		}
  		printf("wdc_atapi_intr: unknown phase 0x%x\n", phase);
  		if (chp->ch_status & WDCS_ERR) {
  			sc_xfer->error = XS_SHORTSENSE;
  			sc_xfer->sense.atapi_sense = chp->ch_error;
  		} else {
  			sc_xfer->error = XS_RESET;
  			wdc_atapi_reset(chp, xfer);
  			return (1);
  		}
  	}
  	WDCDEBUG_PRINT(("wdc_atapi_intr: wdc_atapi_done() (end), error 0x%x "
  	    "sense 0x%x\n", sc_xfer->error, sc_xfer->sense.atapi_sense),
  	    DEBUG_INTR);
  	wdc_atapi_done(chp, xfer);
  	return (1);
  }
  
  int
  wdc_atapi_ctrl(chp, xfer, irq)
  	struct channel_softc *chp;
  	struct wdc_xfer *xfer;
  	int irq;
  {
  	struct scsipi_xfer *sc_xfer = xfer->cmd;
  	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
  	char *errstring = NULL;
  	int delay = (irq == 0) ? ATAPI_DELAY : 0;
  
  	/* Ack interrupt done in wait_for_unbusy */
  again:
  	WDCDEBUG_PRINT(("wdc_atapi_ctrl %s:%d:%d state %d\n",
  	    chp->wdc->sc_dev.dv_xname, chp->channel, drvp->drive, drvp->state),
  	    DEBUG_INTR | DEBUG_FUNCS);
  	bus_space_write_1(chp->cmd_iot, chp->cmd_ioh, wd_sdh,
  	    WDSD_IBM | (xfer->drive << 4));
  	switch (drvp->state) {
  	case PIOMODE:
  		/* Don't try to set mode if controller can't be adjusted */
  		if ((chp->wdc->cap & WDC_CAPABILITY_MODE) == 0)
  			goto ready;
  		/* Also don't try if the drive didn't report its mode */
  		if ((drvp->drive_flags & DRIVE_MODE) == 0)
  			goto ready;;
  		wdccommand(chp, drvp->drive, SET_FEATURES, 0, 0, 0,
  		    0x08 | drvp->PIO_mode, WDSF_SET_MODE);
  		drvp->state = PIOMODE_WAIT;
  		break;
  	case PIOMODE_WAIT:
  		errstring = "piomode";
  		if (wait_for_unbusy(chp, delay))
  			goto timeout;
  		if (chp->ch_status & WDCS_ERR)
  			goto error;
  	/* fall through */
  
  	case DMAMODE:
  		if (drvp->drive_flags & DRIVE_UDMA) {
  			wdccommand(chp, drvp->drive, SET_FEATURES, 0, 0, 0,
  			    0x40 | drvp->UDMA_mode, WDSF_SET_MODE);
  		} else if (drvp->drive_flags & DRIVE_DMA) {
  			wdccommand(chp, drvp->drive, SET_FEATURES, 0, 0, 0,
  			    0x20 | drvp->DMA_mode, WDSF_SET_MODE);
  		} else {
  			goto ready;
  		}
  		drvp->state = DMAMODE_WAIT;
  		break;
  	case DMAMODE_WAIT:
  		errstring = "dmamode";
  		if (wait_for_unbusy(chp, delay))
  			goto timeout;
  		if (chp->ch_status & WDCS_ERR)
  			goto error;
  	/* fall through */
  
  	case READY:
  	ready:
  		drvp->state = READY;
  		xfer->c_intr = wdc_atapi_intr;
  		wdc_atapi_start(chp, xfer);
  		return 1;
  	}
  	if ((sc_xfer->flags & SCSI_POLL) == 0) {
  		chp->ch_flags |= WDCF_IRQ_WAIT;
  		xfer->c_intr = wdc_atapi_ctrl;
  		timeout(wdctimeout, chp, sc_xfer->timeout * hz / 1000);
  	} else {
  		goto again;
  	}
  	return 1;
  
  timeout:
  	if (irq && (xfer->c_flags & C_TIMEOU) == 0) {
  		return 0; /* IRQ was not for us */
  	}
  	printf("%s:%d:%d: %s timed out\n",
  	    chp->wdc->sc_dev.dv_xname, chp->channel, xfer->drive, errstring);
  	sc_xfer->error = XS_TIMEOUT;
  	wdc_atapi_reset(chp, xfer);
  	return 1;
  error:
  	printf("%s:%d:%d: %s ",
  	    chp->wdc->sc_dev.dv_xname, chp->channel, xfer->drive,
  	    errstring);
  	printf("error (0x%x)\n", chp->ch_error);
  	sc_xfer->error = XS_SHORTSENSE;
  	sc_xfer->sense.atapi_sense = chp->ch_error;
  	wdc_atapi_reset(chp, xfer);
  	return 1;
  }
  
  void
  wdc_atapi_done(chp, xfer)
  	struct channel_softc *chp;
  	struct wdc_xfer *xfer;
  {
  	struct scsipi_xfer *sc_xfer = xfer->cmd;
  	int need_done =  xfer->c_flags & C_NEEDDONE;
  	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
  
  	WDCDEBUG_PRINT(("wdc_atapi_done %s:%d:%d: flags 0x%x\n",
  	    chp->wdc->sc_dev.dv_xname, chp->channel, xfer->drive,
  	    (u_int)xfer->c_flags), DEBUG_XFERS);
  	/* remove this command from xfer queue */
  	wdc_free_xfer(chp, xfer);
  	sc_xfer->flags |= ITSDONE;
  	if (drvp->n_dmaerrs ||
  	  (sc_xfer->error != XS_NOERROR && sc_xfer->error != XS_SENSE &&
  	  sc_xfer->error != XS_SHORTSENSE)) {
  		drvp->n_dmaerrs = 0;
  		wdc_downgrade_mode(drvp);
  	}
  	    
  	if (need_done) {
  		WDCDEBUG_PRINT(("wdc_atapi_done: scsipi_done\n"), DEBUG_XFERS);
  		scsipi_done(sc_xfer);
  	}
  	WDCDEBUG_PRINT(("wdcstart from wdc_atapi_done, flags 0x%x\n",
  	    chp->ch_flags), DEBUG_XFERS);
  	wdcstart(chp);
  }
  
  void
  wdc_atapi_reset(chp, xfer)
  	struct channel_softc *chp;
  	struct wdc_xfer *xfer;
  {
  	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->drive];
  	struct scsipi_xfer *sc_xfer = xfer->cmd;
  
  	wdccommandshort(chp, xfer->drive, ATAPI_SOFT_RESET);
  	drvp->state = 0;
  	if (wait_for_unbusy(chp, WDC_RESET_WAIT) != 0) {
  		printf("%s:%d:%d: reset failed\n",
  		    chp->wdc->sc_dev.dv_xname, chp->channel,
  		    xfer->drive);
  		sc_xfer->error = XS_SELTIMEOUT;
  	}
  	wdc_atapi_done(chp, xfer);
  	return;
  }
  