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atapi_wdc.c revision 1.80
      1 /*	$NetBSD: atapi_wdc.c,v 1.80 2004/08/12 21:10:18 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1998, 2001 Manuel Bouyer.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. All advertising materials mentioning features or use of this software
     15  *    must display the following acknowledgement:
     16  *	This product includes software developed by Manuel Bouyer.
     17  * 4. The name of the author may not be used to endorse or promote products
     18  *    derived from this software without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: atapi_wdc.c,v 1.80 2004/08/12 21:10:18 thorpej Exp $");
     34 
     35 #ifndef WDCDEBUG
     36 #define WDCDEBUG
     37 #endif /* WDCDEBUG */
     38 
     39 #include <sys/param.h>
     40 #include <sys/systm.h>
     41 #include <sys/kernel.h>
     42 #include <sys/file.h>
     43 #include <sys/stat.h>
     44 #include <sys/buf.h>
     45 #include <sys/malloc.h>
     46 #include <sys/device.h>
     47 #include <sys/syslog.h>
     48 #include <sys/proc.h>
     49 #include <sys/dvdio.h>
     50 
     51 #include <machine/intr.h>
     52 #include <machine/bus.h>
     53 
     54 #ifndef __BUS_SPACE_HAS_STREAM_METHODS
     55 #define	bus_space_write_multi_stream_2	bus_space_write_multi_2
     56 #define	bus_space_write_multi_stream_4	bus_space_write_multi_4
     57 #define	bus_space_read_multi_stream_2	bus_space_read_multi_2
     58 #define	bus_space_read_multi_stream_4	bus_space_read_multi_4
     59 #endif /* __BUS_SPACE_HAS_STREAM_METHODS */
     60 
     61 #include <dev/ata/atareg.h>
     62 #include <dev/ata/atavar.h>
     63 #include <dev/ic/wdcreg.h>
     64 #include <dev/ic/wdcvar.h>
     65 
     66 #include <dev/scsipi/scsi_all.h> /* for SCSI status */
     67 
     68 #define DEBUG_INTR   0x01
     69 #define DEBUG_XFERS  0x02
     70 #define DEBUG_STATUS 0x04
     71 #define DEBUG_FUNCS  0x08
     72 #define DEBUG_PROBE  0x10
     73 #ifdef WDCDEBUG
     74 int wdcdebug_atapi_mask = 0;
     75 #define WDCDEBUG_PRINT(args, level) \
     76 	if (wdcdebug_atapi_mask & (level)) \
     77 		printf args
     78 #else
     79 #define WDCDEBUG_PRINT(args, level)
     80 #endif
     81 
     82 #define ATAPI_DELAY 10	/* 10 ms, this is used only before sending a cmd */
     83 #define ATAPI_MODE_DELAY 1000	/* 1s, timeout for SET_FEATYRE cmds */
     84 
     85 static int	wdc_atapi_get_params(struct scsipi_channel *, int,
     86 				     struct ataparams *);
     87 static void	wdc_atapi_probe_device(struct atapibus_softc *, int);
     88 static void	wdc_atapi_minphys (struct buf *bp);
     89 static void	wdc_atapi_start(struct wdc_channel *,struct ata_xfer *);
     90 static int	wdc_atapi_intr(struct wdc_channel *, struct ata_xfer *, int);
     91 static void	wdc_atapi_kill_xfer(struct wdc_channel *,
     92 				    struct ata_xfer *, int);
     93 static void	wdc_atapi_phase_complete(struct ata_xfer *);
     94 static void	wdc_atapi_done(struct wdc_channel *, struct ata_xfer *);
     95 static void	wdc_atapi_reset(struct wdc_channel *, struct ata_xfer *);
     96 static void	wdc_atapi_scsipi_request(struct scsipi_channel *,
     97 					 scsipi_adapter_req_t, void *);
     98 static void	wdc_atapi_kill_pending(struct scsipi_periph *);
     99 static void	wdc_atapi_polldsc(void *arg);
    100 
    101 #define MAX_SIZE MAXPHYS
    102 
    103 static const struct scsipi_bustype wdc_atapi_bustype = {
    104 	SCSIPI_BUSTYPE_ATAPI,
    105 	atapi_scsipi_cmd,
    106 	atapi_interpret_sense,
    107 	atapi_print_addr,
    108 	wdc_atapi_kill_pending,
    109 };
    110 
    111 void
    112 wdc_atapibus_attach(struct atabus_softc *ata_sc)
    113 {
    114 	struct wdc_channel *chp = ata_sc->sc_chan;
    115 	struct wdc_softc *wdc = chp->ch_wdc;
    116 	struct scsipi_adapter *adapt = &wdc->sc_atapi_adapter._generic;
    117 	struct scsipi_channel *chan = &chp->ch_atapi_channel;
    118 
    119 	/*
    120 	 * Fill in the scsipi_adapter.
    121 	 */
    122 	adapt->adapt_dev = &wdc->sc_dev;
    123 	adapt->adapt_nchannels = wdc->nchannels;
    124 	adapt->adapt_request = wdc_atapi_scsipi_request;
    125 	adapt->adapt_minphys = wdc_atapi_minphys;
    126 	if (wdc->cap & WDC_CAPABILITY_NOIRQ)
    127 		adapt->adapt_flags |= SCSIPI_ADAPT_POLL_ONLY;
    128 	wdc->sc_atapi_adapter.atapi_probe_device = wdc_atapi_probe_device;
    129 
    130 	/*
    131 	 * Fill in the scsipi_channel.
    132 	 */
    133 	memset(chan, 0, sizeof(*chan));
    134 	chan->chan_adapter = adapt;
    135 	chan->chan_bustype = &wdc_atapi_bustype;
    136 	chan->chan_channel = chp->ch_channel;
    137 	chan->chan_flags = SCSIPI_CHAN_OPENINGS;
    138 	chan->chan_openings = 1;
    139 	chan->chan_max_periph = 1;
    140 	chan->chan_ntargets = 2;
    141 	chan->chan_nluns = 1;
    142 
    143 	chp->atapibus = config_found(&ata_sc->sc_dev, chan, atapiprint);
    144 }
    145 
    146 static void
    147 wdc_atapi_minphys(struct buf *bp)
    148 {
    149 
    150 	if (bp->b_bcount > MAX_SIZE)
    151 		bp->b_bcount = MAX_SIZE;
    152 	minphys(bp);
    153 }
    154 
    155 /*
    156  * Kill off all pending xfers for a periph.
    157  *
    158  * Must be called at splbio().
    159  */
    160 static void
    161 wdc_atapi_kill_pending(struct scsipi_periph *periph)
    162 {
    163 	struct wdc_softc *wdc =
    164 	    (void *)periph->periph_channel->chan_adapter->adapt_dev;
    165 	struct wdc_channel *chp =
    166 	    wdc->channels[periph->periph_channel->chan_channel];
    167 
    168 	wdc_kill_pending(&chp->ch_drive[periph->periph_target]);
    169 }
    170 
    171 static void
    172 wdc_atapi_kill_xfer(struct wdc_channel *chp, struct ata_xfer *xfer, int reason)
    173 {
    174 	struct scsipi_xfer *sc_xfer = xfer->c_cmd;
    175 
    176 	/* remove this command from xfer queue */
    177 	switch (reason) {
    178 	case KILL_GONE:
    179 		sc_xfer->error = XS_DRIVER_STUFFUP;
    180 		break;
    181 	case KILL_RESET:
    182 		sc_xfer->error = XS_RESET;
    183 		break;
    184 	default:
    185 		printf("wdc_ata_bio_kill_xfer: unknown reason %d\n",
    186 		    reason);
    187 		panic("wdc_ata_bio_kill_xfer");
    188 	}
    189 	wdc_free_xfer(chp, xfer);
    190 	scsipi_done(sc_xfer);
    191 }
    192 
    193 static int
    194 wdc_atapi_get_params(struct scsipi_channel *chan, int drive,
    195     struct ataparams *id)
    196 {
    197 	struct wdc_softc *wdc = (void *)chan->chan_adapter->adapt_dev;
    198 	struct wdc_channel *chp = wdc->channels[chan->chan_channel];
    199 	struct ata_command ata_c;
    200 
    201 	/* if no ATAPI device detected at wdc attach time, skip */
    202 	if ((chp->ch_drive[drive].drive_flags & DRIVE_ATAPI) == 0) {
    203 		WDCDEBUG_PRINT(("wdc_atapi_get_params: drive %d not present\n",
    204 		    drive), DEBUG_PROBE);
    205 		return -1;
    206 	}
    207 
    208 	memset(&ata_c, 0, sizeof(struct ata_command));
    209 	ata_c.r_command = ATAPI_SOFT_RESET;
    210 	ata_c.r_st_bmask = 0;
    211 	ata_c.r_st_pmask = 0;
    212 	ata_c.flags = AT_WAIT | AT_POLL;
    213 	ata_c.timeout = WDC_RESET_WAIT;
    214 	if (wdc_exec_command(&chp->ch_drive[drive], &ata_c) != ATACMD_COMPLETE) {
    215 		printf("wdc_atapi_get_params: ATAPI_SOFT_RESET failed for"
    216 		    " drive %s:%d:%d: driver failed\n",
    217 		    wdc->sc_dev.dv_xname, chp->ch_channel, drive);
    218 		panic("wdc_atapi_get_params");
    219 	}
    220 	if (ata_c.flags & (AT_ERROR | AT_TIMEOU | AT_DF)) {
    221 		WDCDEBUG_PRINT(("wdc_atapi_get_params: ATAPI_SOFT_RESET "
    222 		    "failed for drive %s:%d:%d: error 0x%x\n",
    223 		    wdc->sc_dev.dv_xname, chp->ch_channel, drive,
    224 		    ata_c.r_error), DEBUG_PROBE);
    225 		return -1;
    226 	}
    227 	chp->ch_drive[drive].state = 0;
    228 
    229 	bus_space_read_1(chp->cmd_iot, chp->cmd_iohs[wd_status], 0);
    230 
    231 	/* Some ATAPI devices need a bit more time after software reset. */
    232 	delay(5000);
    233 	if (ata_get_params(&chp->ch_drive[drive], AT_WAIT, id) != 0) {
    234 		WDCDEBUG_PRINT(("wdc_atapi_get_params: ATAPI_IDENTIFY_DEVICE "
    235 		    "failed for drive %s:%d:%d: error 0x%x\n",
    236 		    wdc->sc_dev.dv_xname, chp->ch_channel, drive,
    237 		    ata_c.r_error), DEBUG_PROBE);
    238 		return -1;
    239 	}
    240 	return 0;
    241 }
    242 
    243 static void
    244 wdc_atapi_probe_device(struct atapibus_softc *sc, int target)
    245 {
    246 	struct scsipi_channel *chan = sc->sc_channel;
    247 	struct scsipi_periph *periph;
    248 	struct ataparams ids;
    249 	struct ataparams *id = &ids;
    250 	struct wdc_softc *wdc = (void *)chan->chan_adapter->adapt_dev;
    251 	struct wdc_channel *chp = wdc->channels[chan->chan_channel];
    252 	struct ata_drive_datas *drvp = &chp->ch_drive[target];
    253 	struct scsipibus_attach_args sa;
    254 	char serial_number[21], model[41], firmware_revision[9];
    255 
    256 	/* skip if already attached */
    257 	if (scsipi_lookup_periph(chan, target, 0) != NULL)
    258 		return;
    259 
    260 	if (wdc_atapi_get_params(chan, target, id) == 0) {
    261 #ifdef ATAPI_DEBUG_PROBE
    262 		printf("%s drive %d: cmdsz 0x%x drqtype 0x%x\n",
    263 		    sc->sc_dev.dv_xname, target,
    264 		    id->atap_config & ATAPI_CFG_CMD_MASK,
    265 		    id->atap_config & ATAPI_CFG_DRQ_MASK);
    266 #endif
    267 		periph = scsipi_alloc_periph(M_NOWAIT);
    268 		if (periph == NULL) {
    269 			printf("%s: unable to allocate periph for drive %d\n",
    270 			    sc->sc_dev.dv_xname, target);
    271 			return;
    272 		}
    273 		periph->periph_dev = NULL;
    274 		periph->periph_channel = chan;
    275 		periph->periph_switch = &atapi_probe_periphsw;
    276 		periph->periph_target = target;
    277 		periph->periph_lun = 0;
    278 		periph->periph_quirks = PQUIRK_ONLYBIG;
    279 
    280 #ifdef SCSIPI_DEBUG
    281 		if (SCSIPI_DEBUG_TYPE == SCSIPI_BUSTYPE_ATAPI &&
    282 		    SCSIPI_DEBUG_TARGET == target)
    283 			periph->periph_dbflags |= SCSIPI_DEBUG_FLAGS;
    284 #endif
    285 		periph->periph_type = ATAPI_CFG_TYPE(id->atap_config);
    286 		if (id->atap_config & ATAPI_CFG_REMOV)
    287 			periph->periph_flags |= PERIPH_REMOVABLE;
    288 		if (periph->periph_type == T_SEQUENTIAL)
    289 			drvp->drive_flags |= DRIVE_ATAPIST;
    290 
    291 		sa.sa_periph = periph;
    292 		sa.sa_inqbuf.type =  ATAPI_CFG_TYPE(id->atap_config);
    293 		sa.sa_inqbuf.removable = id->atap_config & ATAPI_CFG_REMOV ?
    294 		    T_REMOV : T_FIXED;
    295 		scsipi_strvis(model, 40, id->atap_model, 40);
    296 		scsipi_strvis(serial_number, 20, id->atap_serial, 20);
    297 		scsipi_strvis(firmware_revision, 8, id->atap_revision, 8);
    298 		sa.sa_inqbuf.vendor = model;
    299 		sa.sa_inqbuf.product = serial_number;
    300 		sa.sa_inqbuf.revision = firmware_revision;
    301 
    302 		/*
    303 		 * Determine the operating mode capabilities of the device.
    304 		 */
    305 		if ((id->atap_config & ATAPI_CFG_CMD_MASK) == ATAPI_CFG_CMD_16)
    306 			periph->periph_cap |= PERIPH_CAP_CMD16;
    307 		/* XXX This is gross. */
    308 		periph->periph_cap |= (id->atap_config & ATAPI_CFG_DRQ_MASK);
    309 
    310 		drvp->drv_softc = atapi_probe_device(sc, target, periph, &sa);
    311 
    312 		if (drvp->drv_softc)
    313 			ata_probe_caps(drvp);
    314 		else
    315 			drvp->drive_flags &= ~DRIVE_ATAPI;
    316 	} else {
    317 		drvp->drive_flags &= ~DRIVE_ATAPI;
    318 	}
    319 }
    320 
    321 static void
    322 wdc_atapi_scsipi_request(struct scsipi_channel *chan, scsipi_adapter_req_t req,
    323     void *arg)
    324 {
    325 	struct scsipi_adapter *adapt = chan->chan_adapter;
    326 	struct scsipi_periph *periph;
    327 	struct scsipi_xfer *sc_xfer;
    328 	struct wdc_softc *wdc = (void *)adapt->adapt_dev;
    329 	struct ata_xfer *xfer;
    330 	int channel = chan->chan_channel;
    331 	int drive, s;
    332 
    333 	switch (req) {
    334 	case ADAPTER_REQ_RUN_XFER:
    335 		sc_xfer = arg;
    336 		periph = sc_xfer->xs_periph;
    337 		drive = periph->periph_target;
    338 
    339 		WDCDEBUG_PRINT(("wdc_atapi_scsipi_request %s:%d:%d\n",
    340 		    wdc->sc_dev.dv_xname, channel, drive), DEBUG_XFERS);
    341 		if ((wdc->sc_dev.dv_flags & DVF_ACTIVE) == 0) {
    342 			sc_xfer->error = XS_DRIVER_STUFFUP;
    343 			scsipi_done(sc_xfer);
    344 			return;
    345 		}
    346 
    347 		xfer = wdc_get_xfer(WDC_NOSLEEP);
    348 		if (xfer == NULL) {
    349 			sc_xfer->error = XS_RESOURCE_SHORTAGE;
    350 			scsipi_done(sc_xfer);
    351 			return;
    352 		}
    353 
    354 		if (sc_xfer->xs_control & XS_CTL_POLL)
    355 			xfer->c_flags |= C_POLL;
    356 		if ((wdc->channels[channel]->ch_drive[drive].drive_flags &
    357 		    (DRIVE_DMA | DRIVE_UDMA)) && sc_xfer->datalen > 0)
    358 			xfer->c_flags |= C_DMA;
    359 		xfer->c_drive = drive;
    360 		xfer->c_flags |= C_ATAPI;
    361 		if (sc_xfer->cmd->opcode == GPCMD_REPORT_KEY ||
    362 		    sc_xfer->cmd->opcode == GPCMD_SEND_KEY ||
    363 		    sc_xfer->cmd->opcode == GPCMD_READ_DVD_STRUCTURE) {
    364 			/*
    365 			 * DVD authentication commands must always be done in
    366 			 * PIO mode.
    367 			 */
    368 			xfer->c_flags &= ~C_DMA;
    369 		}
    370 		/*
    371 		 * DMA can't deal with transfers which are not a multiple of
    372 		 * 2 bytes. It's a bug to request such transfers for ATAPI
    373 		 * but as the request can come from userland, we have to
    374 		 * protect against it.
    375 		 * Also some devices seems to not handle DMA xfers of less than
    376 		 * 4 bytes.
    377 		 */
    378 		if (sc_xfer->datalen < 4 || (sc_xfer->datalen & 0x01))
    379 			xfer->c_flags &= ~C_DMA;
    380 
    381 		xfer->c_cmd = sc_xfer;
    382 		xfer->c_databuf = sc_xfer->data;
    383 		xfer->c_bcount = sc_xfer->datalen;
    384 		xfer->c_start = wdc_atapi_start;
    385 		xfer->c_intr = wdc_atapi_intr;
    386 		xfer->c_kill_xfer = wdc_atapi_kill_xfer;
    387 		xfer->c_dscpoll = 0;
    388 		s = splbio();
    389 		wdc_exec_xfer(wdc->channels[channel], xfer);
    390 #ifdef DIAGNOSTIC
    391 		if ((sc_xfer->xs_control & XS_CTL_POLL) != 0 &&
    392 		    (sc_xfer->xs_status & XS_STS_DONE) == 0)
    393 			panic("wdc_atapi_scsipi_request: polled command "
    394 			    "not done");
    395 #endif
    396 		splx(s);
    397 		return;
    398 
    399 	default:
    400 		/* Not supported, nothing to do. */
    401 		;
    402 	}
    403 }
    404 
    405 static void
    406 wdc_atapi_start(struct wdc_channel *chp, struct ata_xfer *xfer)
    407 {
    408 	struct wdc_softc *wdc = chp->ch_wdc;
    409 	struct scsipi_xfer *sc_xfer = xfer->c_cmd;
    410 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->c_drive];
    411 	int wait_flags = (sc_xfer->xs_control & XS_CTL_POLL) ? AT_POLL : 0;
    412 	char *errstring;
    413 
    414 	WDCDEBUG_PRINT(("wdc_atapi_start %s:%d:%d, scsi flags 0x%x \n",
    415 	    wdc->sc_dev.dv_xname, chp->ch_channel, drvp->drive,
    416 	    sc_xfer->xs_control), DEBUG_XFERS);
    417 	if ((xfer->c_flags & C_DMA) && (drvp->n_xfers <= NXFER))
    418 		drvp->n_xfers++;
    419 	/* Do control operations specially. */
    420 	if (__predict_false(drvp->state < READY)) {
    421 		/* If it's not a polled command, we need the kenrel thread */
    422 		if ((sc_xfer->xs_control & XS_CTL_POLL) == 0 &&
    423 		    (chp->ch_flags & WDCF_TH_RUN) == 0) {
    424 			chp->ch_queue->queue_freeze++;
    425 			wakeup(&chp->ch_thread);
    426 			return;
    427 		}
    428 		/*
    429 		 * disable interrupts, all commands here should be quick
    430 		 * enouth to be able to poll, and we don't go here that often
    431 		 */
    432 		 bus_space_write_1(chp->ctl_iot, chp->ctl_ioh, wd_aux_ctlr,
    433 		     WDCTL_4BIT | WDCTL_IDS);
    434 		if (wdc->cap & WDC_CAPABILITY_SELECT)
    435 			wdc->select(chp, xfer->c_drive);
    436 		bus_space_write_1(chp->cmd_iot, chp->cmd_iohs[wd_sdh], 0,
    437 		    WDSD_IBM | (xfer->c_drive << 4));
    438 		/* Don't try to set mode if controller can't be adjusted */
    439 		if ((wdc->cap & WDC_CAPABILITY_MODE) == 0)
    440 			goto ready;
    441 		/* Also don't try if the drive didn't report its mode */
    442 		if ((drvp->drive_flags & DRIVE_MODE) == 0)
    443 			goto ready;
    444 		errstring = "unbusy";
    445 		if (wdc_wait_for_unbusy(chp, ATAPI_DELAY, wait_flags))
    446 			goto timeout;
    447 		wdccommand(chp, drvp->drive, SET_FEATURES, 0, 0, 0,
    448 		    0x08 | drvp->PIO_mode, WDSF_SET_MODE);
    449 		errstring = "piomode";
    450 		if (wdc_wait_for_unbusy(chp, ATAPI_MODE_DELAY, wait_flags))
    451 			goto timeout;
    452 		if (chp->ch_status & WDCS_ERR) {
    453 			if (chp->ch_error == WDCE_ABRT) {
    454 				/*
    455 				 * Some ATAPI drives reject PIO settings.
    456 				 * Fall back to PIO mode 3 since that's the
    457 				 * minimum for ATAPI.
    458 				 */
    459 				printf("%s:%d:%d: PIO mode %d rejected, "
    460 				    "falling back to PIO mode 3\n",
    461 				    wdc->sc_dev.dv_xname,
    462 				    chp->ch_channel, xfer->c_drive,
    463 				    drvp->PIO_mode);
    464 				if (drvp->PIO_mode > 3)
    465 					drvp->PIO_mode = 3;
    466 			} else
    467 				goto error;
    468 		}
    469 		if (drvp->drive_flags & DRIVE_UDMA) {
    470 			wdccommand(chp, drvp->drive, SET_FEATURES, 0, 0, 0,
    471 			    0x40 | drvp->UDMA_mode, WDSF_SET_MODE);
    472 		} else if (drvp->drive_flags & DRIVE_DMA) {
    473 			wdccommand(chp, drvp->drive, SET_FEATURES, 0, 0, 0,
    474 			    0x20 | drvp->DMA_mode, WDSF_SET_MODE);
    475 		} else {
    476 			goto ready;
    477 		}
    478 		errstring = "dmamode";
    479 		if (wdc_wait_for_unbusy(chp, ATAPI_MODE_DELAY, wait_flags))
    480 			goto timeout;
    481 		if (chp->ch_status & WDCS_ERR) {
    482 			if (chp->ch_error == WDCE_ABRT) {
    483 				if (drvp->drive_flags & DRIVE_UDMA)
    484 					goto error;
    485 				else {
    486 					/*
    487 					 * The drive rejected our DMA setting.
    488 					 * Fall back to mode 1.
    489 					 */
    490 					printf("%s:%d:%d: DMA mode %d rejected, "
    491 					    "falling back to DMA mode 0\n",
    492 					    wdc->sc_dev.dv_xname,
    493 					    chp->ch_channel, xfer->c_drive,
    494 					    drvp->DMA_mode);
    495 					if (drvp->DMA_mode > 0)
    496 						drvp->DMA_mode = 0;
    497 				}
    498 			} else
    499 				goto error;
    500 		}
    501 ready:
    502 		drvp->state = READY;
    503 		bus_space_write_1(chp->ctl_iot, chp->ctl_ioh, wd_aux_ctlr,
    504 		    WDCTL_4BIT);
    505 		delay(10); /* some drives need a little delay here */
    506 	}
    507 	/* start timeout machinery */
    508 	if ((sc_xfer->xs_control & XS_CTL_POLL) == 0)
    509 		callout_reset(&chp->ch_callout, mstohz(sc_xfer->timeout),
    510 		    wdctimeout, chp);
    511 
    512 	if (wdc->cap & WDC_CAPABILITY_SELECT)
    513 		wdc->select(chp, xfer->c_drive);
    514 	bus_space_write_1(chp->cmd_iot, chp->cmd_iohs[wd_sdh], 0,
    515 	    WDSD_IBM | (xfer->c_drive << 4));
    516 	switch (wdc_wait_for_unbusy(chp, ATAPI_DELAY, wait_flags)  < 0) {
    517 	case WDCWAIT_OK:
    518 		break;
    519 	case WDCWAIT_TOUT:
    520 		printf("wdc_atapi_start: not ready, st = %02x\n",
    521 		    chp->ch_status);
    522 		sc_xfer->error = XS_TIMEOUT;
    523 		wdc_atapi_reset(chp, xfer);
    524 		return;
    525 	case WDCWAIT_THR:
    526 		return;
    527 	}
    528 
    529 	/*
    530 	 * Even with WDCS_ERR, the device should accept a command packet
    531 	 * Limit length to what can be stuffed into the cylinder register
    532 	 * (16 bits).  Some CD-ROMs seem to interpret '0' as 65536,
    533 	 * but not all devices do that and it's not obvious from the
    534 	 * ATAPI spec that that behaviour should be expected.  If more
    535 	 * data is necessary, multiple data transfer phases will be done.
    536 	 */
    537 
    538 	wdccommand(chp, xfer->c_drive, ATAPI_PKT_CMD,
    539 	    xfer->c_bcount <= 0xffff ? xfer->c_bcount : 0xffff,
    540 	    0, 0, 0,
    541 	    (xfer->c_flags & C_DMA) ? ATAPI_PKT_CMD_FTRE_DMA : 0);
    542 
    543 	/*
    544 	 * If there is no interrupt for CMD input, busy-wait for it (done in
    545 	 * the interrupt routine. If it is a polled command, call the interrupt
    546 	 * routine until command is done.
    547 	 */
    548 	if ((sc_xfer->xs_periph->periph_cap & ATAPI_CFG_DRQ_MASK) !=
    549 	    ATAPI_CFG_IRQ_DRQ || (sc_xfer->xs_control & XS_CTL_POLL)) {
    550 		/* Wait for at last 400ns for status bit to be valid */
    551 		DELAY(1);
    552 		wdc_atapi_intr(chp, xfer, 0);
    553 	} else {
    554 		chp->ch_flags |= WDCF_IRQ_WAIT;
    555 	}
    556 	if (sc_xfer->xs_control & XS_CTL_POLL) {
    557 		if (chp->ch_flags & WDCF_DMA_WAIT) {
    558 			wdc_dmawait(chp, xfer, sc_xfer->timeout);
    559 			chp->ch_flags &= ~WDCF_DMA_WAIT;
    560 		}
    561 		while ((sc_xfer->xs_status & XS_STS_DONE) == 0) {
    562 			/* Wait for at last 400ns for status bit to be valid */
    563 			DELAY(1);
    564 			wdc_atapi_intr(chp, xfer, 0);
    565 		}
    566 	}
    567 	return;
    568 timeout:
    569 	printf("%s:%d:%d: %s timed out\n",
    570 	    wdc->sc_dev.dv_xname, chp->ch_channel, xfer->c_drive,
    571 	    errstring);
    572 	sc_xfer->error = XS_TIMEOUT;
    573 	bus_space_write_1(chp->ctl_iot, chp->ctl_ioh, wd_aux_ctlr, WDCTL_4BIT);
    574 	delay(10); /* some drives need a little delay here */
    575 	wdc_atapi_reset(chp, xfer);
    576 	return;
    577 error:
    578 	printf("%s:%d:%d: %s ",
    579 	    wdc->sc_dev.dv_xname, chp->ch_channel, xfer->c_drive,
    580 	    errstring);
    581 	printf("error (0x%x)\n", chp->ch_error);
    582 	sc_xfer->error = XS_SHORTSENSE;
    583 	sc_xfer->sense.atapi_sense = chp->ch_error;
    584 	bus_space_write_1(chp->ctl_iot, chp->ctl_ioh, wd_aux_ctlr, WDCTL_4BIT);
    585 	delay(10); /* some drives need a little delay here */
    586 	wdc_atapi_reset(chp, xfer);
    587 	return;
    588 }
    589 
    590 static int
    591 wdc_atapi_intr(struct wdc_channel *chp, struct ata_xfer *xfer, int irq)
    592 {
    593 	struct wdc_softc *wdc = chp->ch_wdc;
    594 	struct scsipi_xfer *sc_xfer = xfer->c_cmd;
    595 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->c_drive];
    596 	int len, phase, i, retries=0;
    597 	int ire;
    598 	int dma_flags = 0;
    599 	void *cmd;
    600 
    601 	WDCDEBUG_PRINT(("wdc_atapi_intr %s:%d:%d\n",
    602 	    wdc->sc_dev.dv_xname, chp->ch_channel, drvp->drive),
    603 	    DEBUG_INTR);
    604 
    605 	/* Is it not a transfer, but a control operation? */
    606 	if (drvp->state < READY) {
    607 		printf("%s:%d:%d: bad state %d in wdc_atapi_intr\n",
    608 		    wdc->sc_dev.dv_xname, chp->ch_channel, xfer->c_drive,
    609 		    drvp->state);
    610 		panic("wdc_atapi_intr: bad state");
    611 	}
    612 	/*
    613 	 * If we missed an interrupt in a PIO transfer, reset and restart.
    614 	 * Don't try to continue transfer, we may have missed cycles.
    615 	 */
    616 	if ((xfer->c_flags & (C_TIMEOU | C_DMA)) == C_TIMEOU) {
    617 		sc_xfer->error = XS_TIMEOUT;
    618 		wdc_atapi_reset(chp, xfer);
    619 		return 1;
    620 	}
    621 
    622 	/* Ack interrupt done in wdc_wait_for_unbusy */
    623 	if (wdc->cap & WDC_CAPABILITY_SELECT)
    624 		wdc->select(chp, xfer->c_drive);
    625 	bus_space_write_1(chp->cmd_iot, chp->cmd_iohs[wd_sdh], 0,
    626 	    WDSD_IBM | (xfer->c_drive << 4));
    627 	if (wdc_wait_for_unbusy(chp,
    628 	    (irq == 0) ? sc_xfer->timeout : 0, AT_POLL) == WDCWAIT_TOUT) {
    629 		if (irq && (xfer->c_flags & C_TIMEOU) == 0)
    630 			return 0; /* IRQ was not for us */
    631 		printf("%s:%d:%d: device timeout, c_bcount=%d, c_skip=%d\n",
    632 		    wdc->sc_dev.dv_xname, chp->ch_channel, xfer->c_drive,
    633 		    xfer->c_bcount, xfer->c_skip);
    634 		if (xfer->c_flags & C_DMA) {
    635 			ata_dmaerr(drvp,
    636 			    (xfer->c_flags & C_POLL) ? AT_POLL : 0);
    637 		}
    638 		sc_xfer->error = XS_TIMEOUT;
    639 		wdc_atapi_reset(chp, xfer);
    640 		return 1;
    641 	}
    642 	if (wdc->cap & WDC_CAPABILITY_IRQACK)
    643 		wdc->irqack(chp);
    644 
    645 	/*
    646 	 * If we missed an IRQ and were using DMA, flag it as a DMA error
    647 	 * and reset device.
    648 	 */
    649 	if ((xfer->c_flags & C_TIMEOU) && (xfer->c_flags & C_DMA)) {
    650 		ata_dmaerr(drvp, (xfer->c_flags & C_POLL) ? AT_POLL : 0);
    651 		sc_xfer->error = XS_RESET;
    652 		wdc_atapi_reset(chp, xfer);
    653 		return (1);
    654 	}
    655 	/*
    656 	 * if the request sense command was aborted, report the short sense
    657 	 * previously recorded, else continue normal processing
    658 	 */
    659 
    660 	if (xfer->c_flags & C_DMA)
    661 		dma_flags = (sc_xfer->xs_control & XS_CTL_DATA_IN)
    662 		    ?  WDC_DMA_READ : 0;
    663 again:
    664 	len = bus_space_read_1(chp->cmd_iot, chp->cmd_iohs[wd_cyl_lo], 0) +
    665 	    256 * bus_space_read_1(chp->cmd_iot, chp->cmd_iohs[wd_cyl_hi], 0);
    666 	ire = bus_space_read_1(chp->cmd_iot, chp->cmd_iohs[wd_ireason], 0);
    667 	phase = (ire & (WDCI_CMD | WDCI_IN)) | (chp->ch_status & WDCS_DRQ);
    668 	WDCDEBUG_PRINT(("wdc_atapi_intr: c_bcount %d len %d st 0x%x err 0x%x "
    669 	    "ire 0x%x :", xfer->c_bcount,
    670 	    len, chp->ch_status, chp->ch_error, ire), DEBUG_INTR);
    671 
    672 	switch (phase) {
    673 	case PHASE_CMDOUT:
    674 		cmd = sc_xfer->cmd;
    675 		WDCDEBUG_PRINT(("PHASE_CMDOUT\n"), DEBUG_INTR);
    676 		/* Init the DMA channel if necessary */
    677 		if (xfer->c_flags & C_DMA) {
    678 			if ((*wdc->dma_init)(wdc->dma_arg,
    679 			    chp->ch_channel, xfer->c_drive,
    680 			    xfer->c_databuf, xfer->c_bcount, dma_flags) != 0) {
    681 				sc_xfer->error = XS_DRIVER_STUFFUP;
    682 				break;
    683 			}
    684 		}
    685 
    686 		/* send packet command */
    687 		/* Commands are 12 or 16 bytes long. It's 32-bit aligned */
    688 		wdc->dataout_pio(chp, drvp->drive_flags, cmd, sc_xfer->cmdlen);
    689 
    690 		/* Start the DMA channel if necessary */
    691 		if (xfer->c_flags & C_DMA) {
    692 			(*wdc->dma_start)(wdc->dma_arg,
    693 			    chp->ch_channel, xfer->c_drive);
    694 			chp->ch_flags |= WDCF_DMA_WAIT;
    695 		}
    696 
    697 		if ((sc_xfer->xs_control & XS_CTL_POLL) == 0) {
    698 			chp->ch_flags |= WDCF_IRQ_WAIT;
    699 		}
    700 		return 1;
    701 
    702 	 case PHASE_DATAOUT:
    703 		/* write data */
    704 		WDCDEBUG_PRINT(("PHASE_DATAOUT\n"), DEBUG_INTR);
    705 		if ((sc_xfer->xs_control & XS_CTL_DATA_OUT) == 0 ||
    706 		    (xfer->c_flags & C_DMA) != 0) {
    707 			printf("wdc_atapi_intr: bad data phase DATAOUT\n");
    708 			if (xfer->c_flags & C_DMA) {
    709 				ata_dmaerr(drvp,
    710 				    (xfer->c_flags & C_POLL) ? AT_POLL : 0);
    711 			}
    712 			sc_xfer->error = XS_TIMEOUT;
    713 			wdc_atapi_reset(chp, xfer);
    714 			return 1;
    715 		}
    716 		if (xfer->c_bcount < len) {
    717 			printf("wdc_atapi_intr: warning: write only "
    718 			    "%d of %d requested bytes\n", xfer->c_bcount, len);
    719 			wdc->dataout_pio(chp, drvp->drive_flags,
    720 		    	    (char *)xfer->c_databuf + xfer->c_skip,
    721 			    xfer->c_bcount);
    722 			for (i = xfer->c_bcount; i < len; i += 2)
    723 				bus_space_write_2(chp->cmd_iot,
    724 				    chp->cmd_iohs[wd_data], 0, 0);
    725 			xfer->c_skip += xfer->c_bcount;
    726 			xfer->c_bcount = 0;
    727 		} else {
    728 			wdc->dataout_pio(chp, drvp->drive_flags,
    729 		    	    (char *)xfer->c_databuf + xfer->c_skip, len);
    730 			xfer->c_skip += len;
    731 			xfer->c_bcount -= len;
    732 		}
    733 		if ((sc_xfer->xs_control & XS_CTL_POLL) == 0) {
    734 			chp->ch_flags |= WDCF_IRQ_WAIT;
    735 		}
    736 		return 1;
    737 
    738 	case PHASE_DATAIN:
    739 		/* Read data */
    740 		WDCDEBUG_PRINT(("PHASE_DATAIN\n"), DEBUG_INTR);
    741 		if ((sc_xfer->xs_control & XS_CTL_DATA_IN) == 0 ||
    742 		    (xfer->c_flags & C_DMA) != 0) {
    743 			printf("wdc_atapi_intr: bad data phase DATAIN\n");
    744 			if (xfer->c_flags & C_DMA) {
    745 				ata_dmaerr(drvp,
    746 				    (xfer->c_flags & C_POLL) ? AT_POLL : 0);
    747 			}
    748 			sc_xfer->error = XS_TIMEOUT;
    749 			wdc_atapi_reset(chp, xfer);
    750 			return 1;
    751 		}
    752 		if (xfer->c_bcount < len) {
    753 			printf("wdc_atapi_intr: warning: reading only "
    754 			    "%d of %d bytes\n", xfer->c_bcount, len);
    755 			wdc->datain_pio(chp, drvp->drive_flags,
    756 			    (char *)xfer->c_databuf + xfer->c_skip,
    757 			    xfer->c_bcount);
    758 			wdcbit_bucket(chp, len - xfer->c_bcount);
    759 			xfer->c_skip += xfer->c_bcount;
    760 			xfer->c_bcount = 0;
    761 		} else {
    762 			wdc->datain_pio(chp, drvp->drive_flags,
    763 			    (char *)xfer->c_databuf + xfer->c_skip, len);
    764 			xfer->c_skip += len;
    765 			xfer->c_bcount -=len;
    766 		}
    767 		if ((sc_xfer->xs_control & XS_CTL_POLL) == 0) {
    768 			chp->ch_flags |= WDCF_IRQ_WAIT;
    769 		}
    770 		return 1;
    771 
    772 	case PHASE_ABORTED:
    773 	case PHASE_COMPLETED:
    774 		WDCDEBUG_PRINT(("PHASE_COMPLETED\n"), DEBUG_INTR);
    775 		if (xfer->c_flags & C_DMA) {
    776 			xfer->c_bcount -= sc_xfer->datalen;
    777 		}
    778 		sc_xfer->resid = xfer->c_bcount;
    779 		wdc_atapi_phase_complete(xfer);
    780 		return(1);
    781 
    782 	default:
    783 		if (++retries<500) {
    784 			DELAY(100);
    785 			chp->ch_status = bus_space_read_1(chp->cmd_iot,
    786 			    chp->cmd_iohs[wd_status], 0);
    787 			chp->ch_error = bus_space_read_1(chp->cmd_iot,
    788 			    chp->cmd_iohs[wd_error], 0);
    789 			goto again;
    790 		}
    791 		printf("wdc_atapi_intr: unknown phase 0x%x\n", phase);
    792 		if (chp->ch_status & WDCS_ERR) {
    793 			sc_xfer->error = XS_SHORTSENSE;
    794 			sc_xfer->sense.atapi_sense = chp->ch_error;
    795 		} else {
    796 			if (xfer->c_flags & C_DMA) {
    797 				ata_dmaerr(drvp,
    798 				    (xfer->c_flags & C_POLL) ? AT_POLL : 0);
    799 			}
    800 			sc_xfer->error = XS_RESET;
    801 			wdc_atapi_reset(chp, xfer);
    802 			return (1);
    803 		}
    804 	}
    805 	WDCDEBUG_PRINT(("wdc_atapi_intr: wdc_atapi_done() (end), error 0x%x "
    806 	    "sense 0x%x\n", sc_xfer->error, sc_xfer->sense.atapi_sense),
    807 	    DEBUG_INTR);
    808 	wdc_atapi_done(chp, xfer);
    809 	return (1);
    810 }
    811 
    812 static void
    813 wdc_atapi_phase_complete(struct ata_xfer *xfer)
    814 {
    815 	struct wdc_channel *chp = xfer->c_chp;
    816 	struct wdc_softc *wdc = chp->ch_wdc;
    817 	struct scsipi_xfer *sc_xfer = xfer->c_cmd;
    818 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->c_drive];
    819 
    820 	/* wait for DSC if needed */
    821 	if (drvp->drive_flags & DRIVE_ATAPIST) {
    822 		WDCDEBUG_PRINT(("wdc_atapi_phase_complete(%s:%d:%d) "
    823 		    "polldsc %d\n", wdc->sc_dev.dv_xname, chp->ch_channel,
    824 		    xfer->c_drive, xfer->c_dscpoll), DEBUG_XFERS);
    825 #if 1
    826 		if (cold)
    827 			panic("wdc_atapi_phase_complete: cold");
    828 #endif
    829 		if (wdcwait(chp, WDCS_DSC, WDCS_DSC, 10,
    830 		    AT_POLL) == WDCWAIT_TOUT) {
    831 			/* 10ms not enough, try again in 1 tick */
    832 			if (xfer->c_dscpoll++ >
    833 			    mstohz(sc_xfer->timeout)) {
    834 				printf("%s:%d:%d: wait_for_dsc "
    835 				    "failed\n",
    836 				    wdc->sc_dev.dv_xname,
    837 				    chp->ch_channel, xfer->c_drive);
    838 				sc_xfer->error = XS_TIMEOUT;
    839 				wdc_atapi_reset(chp, xfer);
    840 				return;
    841 			} else
    842 				callout_reset(&chp->ch_callout, 1,
    843 				    wdc_atapi_polldsc, xfer);
    844 			return;
    845 		}
    846 	}
    847 
    848 	/*
    849 	 * Some drive occasionally set WDCS_ERR with
    850 	 * "ATA illegal length indication" in the error
    851 	 * register. If we read some data the sense is valid
    852 	 * anyway, so don't report the error.
    853 	 */
    854 	if (chp->ch_status & WDCS_ERR &&
    855 	    ((sc_xfer->xs_control & XS_CTL_REQSENSE) == 0 ||
    856 	    sc_xfer->resid == sc_xfer->datalen)) {
    857 		/* save the short sense */
    858 		sc_xfer->error = XS_SHORTSENSE;
    859 		sc_xfer->sense.atapi_sense = chp->ch_error;
    860 		if ((sc_xfer->xs_periph->periph_quirks &
    861 		    PQUIRK_NOSENSE) == 0) {
    862 			/* ask scsipi to send a REQUEST_SENSE */
    863 			sc_xfer->error = XS_BUSY;
    864 			sc_xfer->status = SCSI_CHECK;
    865 		} else if (wdc->dma_status &
    866 		    (WDC_DMAST_NOIRQ | WDC_DMAST_ERR)) {
    867 			ata_dmaerr(drvp,
    868 			    (xfer->c_flags & C_POLL) ? AT_POLL : 0);
    869 			sc_xfer->error = XS_RESET;
    870 			wdc_atapi_reset(chp, xfer);
    871 			return;
    872 		}
    873 	}
    874 	if (xfer->c_bcount != 0) {
    875 		WDCDEBUG_PRINT(("wdc_atapi_intr: bcount value is "
    876 		    "%d after io\n", xfer->c_bcount), DEBUG_XFERS);
    877 	}
    878 #ifdef DIAGNOSTIC
    879 	if (xfer->c_bcount < 0) {
    880 		printf("wdc_atapi_intr warning: bcount value "
    881 		    "is %d after io\n", xfer->c_bcount);
    882 	}
    883 #endif
    884 	WDCDEBUG_PRINT(("wdc_atapi_phase_complete: wdc_atapi_done(), "
    885 	    "error 0x%x sense 0x%x\n", sc_xfer->error,
    886 	    sc_xfer->sense.atapi_sense), DEBUG_INTR);
    887 	wdc_atapi_done(chp, xfer);
    888 }
    889 
    890 static void
    891 wdc_atapi_done(struct wdc_channel *chp, struct ata_xfer *xfer)
    892 {
    893 	struct wdc_softc *wdc = chp->ch_wdc;
    894 	struct scsipi_xfer *sc_xfer = xfer->c_cmd;
    895 	int drive = xfer->c_drive;
    896 
    897 	WDCDEBUG_PRINT(("wdc_atapi_done %s:%d:%d: flags 0x%x\n",
    898 	    wdc->sc_dev.dv_xname, chp->ch_channel, xfer->c_drive,
    899 	    (u_int)xfer->c_flags), DEBUG_XFERS);
    900 	callout_stop(&chp->ch_callout);
    901 	/* mark controller inactive and free the command */
    902 	chp->ch_queue->active_xfer = NULL;
    903 	wdc_free_xfer(chp, xfer);
    904 
    905 	if (chp->ch_drive[drive].drive_flags & DRIVE_WAITDRAIN) {
    906 		sc_xfer->error = XS_DRIVER_STUFFUP;
    907 		chp->ch_drive[drive].drive_flags &= ~DRIVE_WAITDRAIN;
    908 		wakeup(&chp->ch_queue->active_xfer);
    909 	}
    910 
    911 	WDCDEBUG_PRINT(("wdc_atapi_done: scsipi_done\n"), DEBUG_XFERS);
    912 	scsipi_done(sc_xfer);
    913 	WDCDEBUG_PRINT(("wdcstart from wdc_atapi_done, flags 0x%x\n",
    914 	    chp->ch_flags), DEBUG_XFERS);
    915 	wdcstart(chp);
    916 }
    917 
    918 static void
    919 wdc_atapi_reset(struct wdc_channel *chp, struct ata_xfer *xfer)
    920 {
    921 	struct wdc_softc *wdc = chp->ch_wdc;
    922 	struct ata_drive_datas *drvp = &chp->ch_drive[xfer->c_drive];
    923 	struct scsipi_xfer *sc_xfer = xfer->c_cmd;
    924 
    925 	wdccommandshort(chp, xfer->c_drive, ATAPI_SOFT_RESET);
    926 	drvp->state = 0;
    927 	if (wdc_wait_for_unbusy(chp, WDC_RESET_WAIT, AT_POLL) != 0) {
    928 		printf("%s:%d:%d: reset failed\n",
    929 		    wdc->sc_dev.dv_xname, chp->ch_channel,
    930 		    xfer->c_drive);
    931 		sc_xfer->error = XS_SELTIMEOUT;
    932 	}
    933 	wdc_atapi_done(chp, xfer);
    934 	return;
    935 }
    936 
    937 static void
    938 wdc_atapi_polldsc(void *arg)
    939 {
    940 
    941 	wdc_atapi_phase_complete(arg);
    942 }
    943