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wdc_obio.c revision 1.47
      1 /*	$NetBSD: wdc_obio.c,v 1.47 2007/10/17 19:55:20 garbled Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998, 2003 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Charles M. Hannum and by Onno van der Linden.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 __KERNEL_RCSID(0, "$NetBSD: wdc_obio.c,v 1.47 2007/10/17 19:55:20 garbled Exp $");
     41 
     42 #include <sys/param.h>
     43 #include <sys/systm.h>
     44 #include <sys/device.h>
     45 #include <sys/malloc.h>
     46 
     47 #include <uvm/uvm_extern.h>
     48 
     49 #include <machine/bus.h>
     50 #include <machine/autoconf.h>
     51 #include <machine/pio.h>
     52 
     53 #include <dev/ata/atareg.h>
     54 #include <dev/ata/atavar.h>
     55 #include <dev/ic/wdcvar.h>
     56 
     57 #include <dev/ofw/openfirm.h>
     58 
     59 #include <macppc/dev/dbdma.h>
     60 
     61 #define WDC_REG_NPORTS		8
     62 #define WDC_AUXREG_OFFSET	0x16
     63 #define WDC_DEFAULT_PIO_IRQ	13	/* XXX */
     64 #define WDC_DEFAULT_DMA_IRQ	2	/* XXX */
     65 
     66 #define WDC_OPTIONS_DMA 0x01
     67 
     68 /*
     69  * XXX This code currently doesn't even try to allow 32-bit data port use.
     70  */
     71 
     72 struct wdc_obio_softc {
     73 	struct wdc_softc sc_wdcdev;
     74 	struct ata_channel *sc_chanptr;
     75 	struct ata_channel sc_channel;
     76 	struct ata_queue sc_chqueue;
     77 	struct wdc_regs sc_wdc_regs;
     78 	bus_space_handle_t sc_dmaregh;
     79 	dbdma_regmap_t *sc_dmareg;
     80 	dbdma_command_t	*sc_dmacmd;
     81 	u_int sc_dmaconf[2];	/* per target value of CONFIG_REG */
     82 	void *sc_ih;
     83 };
     84 
     85 int wdc_obio_probe __P((struct device *, struct cfdata *, void *));
     86 void wdc_obio_attach __P((struct device *, struct device *, void *));
     87 int wdc_obio_detach __P((struct device *, int));
     88 int wdc_obio_dma_init __P((void *, int, int, void *, size_t, int));
     89 void wdc_obio_dma_start __P((void *, int, int));
     90 int wdc_obio_dma_finish __P((void *, int, int, int));
     91 
     92 static void wdc_obio_select __P((struct ata_channel *, int));
     93 static void adjust_timing __P((struct ata_channel *));
     94 static void ata4_adjust_timing __P((struct ata_channel *));
     95 
     96 CFATTACH_DECL(wdc_obio, sizeof(struct wdc_obio_softc),
     97     wdc_obio_probe, wdc_obio_attach, wdc_obio_detach, wdcactivate);
     98 
     99 static const char *ata_names[] = {
    100     "heathrow-ata",
    101     "keylargo-ata",
    102     "ohare-ata",
    103     NULL
    104 };
    105 
    106 int
    107 wdc_obio_probe(parent, match, aux)
    108 	struct device *parent;
    109 	struct cfdata *match;
    110 	void *aux;
    111 {
    112 	struct confargs *ca = aux;
    113 
    114 	/* XXX should not use name */
    115 	if (strcmp(ca->ca_name, "ATA") == 0 ||
    116 	    strcmp(ca->ca_name, "ata") == 0 ||
    117 	    strcmp(ca->ca_name, "ata0") == 0 ||
    118 	    strcmp(ca->ca_name, "ide") == 0)
    119 		return 1;
    120 
    121 	if (of_compatible(ca->ca_node, ata_names) >= 0)
    122 		return 1;
    123 
    124 	return 0;
    125 }
    126 
    127 void
    128 wdc_obio_attach(parent, self, aux)
    129 	struct device *parent, *self;
    130 	void *aux;
    131 {
    132 	struct wdc_obio_softc *sc = (void *)self;
    133 	struct wdc_regs *wdr;
    134 	struct confargs *ca = aux;
    135 	struct ata_channel *chp = &sc->sc_channel;
    136 	int intr, i, type = IST_EDGE;
    137 	int use_dma = 0;
    138 	char path[80];
    139 
    140 	if (device_cfdata(&sc->sc_wdcdev.sc_atac.atac_dev)->cf_flags &
    141 	    WDC_OPTIONS_DMA) {
    142 		if (ca->ca_nreg >= 16 || ca->ca_nintr == -1)
    143 			use_dma = 1;	/* XXX Don't work yet. */
    144 	}
    145 
    146 	if (ca->ca_nintr >= 4 && ca->ca_nreg >= 8) {
    147 		intr = ca->ca_intr[0];
    148 		printf(" irq %d", intr);
    149 		if (ca->ca_nintr > 8) {
    150 			type = ca->ca_intr[1] ? IST_LEVEL : IST_EDGE;
    151 		}
    152 		printf(", %s triggered", (type == IST_EDGE) ? "edge" : "level");
    153 	} else if (ca->ca_nintr == -1) {
    154 		intr = WDC_DEFAULT_PIO_IRQ;
    155 		printf(" irq property not found; using %d", intr);
    156 	} else {
    157 		printf(": couldn't get irq property\n");
    158 		return;
    159 	}
    160 
    161 	if (use_dma)
    162 		printf(": DMA transfer");
    163 
    164 	printf("\n");
    165 
    166 	sc->sc_wdcdev.regs = wdr = &sc->sc_wdc_regs;
    167 
    168 	wdr->cmd_iot = wdr->ctl_iot = ca->ca_tag;
    169 
    170 	if (bus_space_map(wdr->cmd_iot, ca->ca_baseaddr + ca->ca_reg[0],
    171 	    WDC_REG_NPORTS << 4, 0, &wdr->cmd_baseioh) ||
    172 	    bus_space_subregion(wdr->cmd_iot, wdr->cmd_baseioh,
    173 			WDC_AUXREG_OFFSET << 4, 1, &wdr->ctl_ioh)) {
    174 		printf("%s: couldn't map registers\n",
    175 			sc->sc_wdcdev.sc_atac.atac_dev.dv_xname);
    176 		return;
    177 	}
    178 
    179 	for (i = 0; i < WDC_NREG; i++) {
    180 		if (bus_space_subregion(wdr->cmd_iot, wdr->cmd_baseioh, i << 4,
    181 		    i == 0 ? 4 : 1, &wdr->cmd_iohs[i]) != 0) {
    182 			bus_space_unmap(wdr->cmd_iot, wdr->cmd_baseioh,
    183 			    WDC_REG_NPORTS << 4);
    184 			printf("%s: couldn't subregion registers\n",
    185 			    sc->sc_wdcdev.sc_atac.atac_dev.dv_xname);
    186 			return;
    187 		}
    188 	}
    189 #if 0
    190 	wdr->data32iot = wdr->cmd_iot;
    191 	wdr->data32ioh = wdr->cmd_ioh;
    192 #endif
    193 
    194 	sc->sc_ih = intr_establish(intr, type, IPL_BIO, wdcintr, chp);
    195 
    196 	if (use_dma) {
    197 		sc->sc_dmacmd = dbdma_alloc(sizeof(dbdma_command_t) * 20);
    198 		/*
    199 		 * XXX
    200 		 * we don't use ca->ca_reg[3] for size here because at least
    201 		 * on the PB3400c it says 0x200 for both IDE channels ( the
    202 		 * one on the mainboard and the other on the mediabay ) but
    203 		 * their start addresses are only 0x100 apart. Since those
    204 		 * DMA registers are always 0x100 or less we don't really
    205 		 * have to care though
    206 		 */
    207 		if (bus_space_map(wdr->cmd_iot, ca->ca_baseaddr + ca->ca_reg[2],
    208 		    0x100, BUS_SPACE_MAP_LINEAR, &sc->sc_dmaregh)) {
    209 
    210 			aprint_error("%s: unable to map DMA registers (%08x)\n",
    211 			    sc->sc_wdcdev.sc_atac.atac_dev.dv_xname,
    212 			    ca->ca_reg[2]);
    213 			/* should unmap stuff here */
    214 			return;
    215 		}
    216 		sc->sc_dmareg = bus_space_vaddr(wdr->cmd_iot, sc->sc_dmaregh);
    217 
    218 		sc->sc_wdcdev.sc_atac.atac_cap |= ATAC_CAP_DMA;
    219 		sc->sc_wdcdev.sc_atac.atac_dma_cap = 2;
    220 		if (strcmp(ca->ca_name, "ata-4") == 0) {
    221 			sc->sc_wdcdev.sc_atac.atac_cap |= ATAC_CAP_UDMA;
    222 			sc->sc_wdcdev.sc_atac.atac_udma_cap = 4;
    223 			sc->sc_wdcdev.sc_atac.atac_set_modes =
    224 			    ata4_adjust_timing;
    225 		} else {
    226 			sc->sc_wdcdev.sc_atac.atac_set_modes = adjust_timing;
    227 		}
    228 #ifdef notyet
    229 		/* Minimum cycle time is 150ns (DMA MODE 1) on ohare. */
    230 		if (ohare) {
    231 			sc->sc_wdcdev.sc_atac.atac_pio_cap = 3;
    232 			sc->sc_wdcdev.sc_atac.atac_dma_cap = 1;
    233 		}
    234 #endif
    235 	} else {
    236 		/* all non-DMA controllers can use adjust_timing */
    237 		sc->sc_wdcdev.sc_atac.atac_set_modes = adjust_timing;
    238 	}
    239 
    240 	sc->sc_wdcdev.sc_atac.atac_pio_cap = 4;
    241 	sc->sc_wdcdev.sc_atac.atac_cap |= ATAC_CAP_DATA16;
    242 	sc->sc_chanptr = chp;
    243 	sc->sc_wdcdev.sc_atac.atac_channels = &sc->sc_chanptr;
    244 	sc->sc_wdcdev.sc_atac.atac_nchannels = 1;
    245 	sc->sc_wdcdev.dma_arg = sc;
    246 	sc->sc_wdcdev.dma_init = wdc_obio_dma_init;
    247 	sc->sc_wdcdev.dma_start = wdc_obio_dma_start;
    248 	sc->sc_wdcdev.dma_finish = wdc_obio_dma_finish;
    249 	chp->ch_channel = 0;
    250 	chp->ch_atac = &sc->sc_wdcdev.sc_atac;
    251 	chp->ch_queue = &sc->sc_chqueue;
    252 	chp->ch_ndrive = 2;
    253 
    254 	wdc_init_shadow_regs(chp);
    255 
    256 #define OHARE_FEATURE_REG	0xf3000038
    257 
    258 	/* XXX Enable wdc1 by feature reg. */
    259 	memset(path, 0, sizeof(path));
    260 	OF_package_to_path(ca->ca_node, path, sizeof(path));
    261 	if (strcmp(path, "/bandit@F2000000/ohare@10/ata@21000") == 0) {
    262 		u_int x;
    263 
    264 		x = in32rb(OHARE_FEATURE_REG);
    265 		x |= 8;
    266 		out32rb(OHARE_FEATURE_REG, x);
    267 	}
    268 
    269 	wdcattach(chp);
    270 }
    271 
    272 /* Multiword DMA transfer timings */
    273 struct ide_timings {
    274 	int cycle;	/* minimum cycle time [ns] */
    275 	int active;	/* minimum command active time [ns] */
    276 };
    277 static struct ide_timings pio_timing[5] = {
    278 	{ 600, 180 },    /* Mode 0 */
    279 	{ 390, 150 },    /*      1 */
    280 	{ 240, 105 },    /*      2 */
    281 	{ 180,  90 },    /*      3 */
    282 	{ 120,  75 }     /*      4 */
    283 };
    284 static struct ide_timings dma_timing[3] = {
    285 	{ 480, 240 },	/* Mode 0 */
    286 	{ 165,  90 },	/* Mode 1 */
    287 	{ 120,  75 }	/* Mode 2 */
    288 };
    289 
    290 static struct ide_timings udma_timing[5] = {
    291 	{120, 180},	/* Mode 0 */
    292 	{ 90, 150},	/* Mode 1 */
    293 	{ 60, 120},	/* Mode 2 */
    294 	{ 45, 90},	/* Mode 3 */
    295 	{ 30, 90}	/* Mode 4 */
    296 };
    297 
    298 #define TIME_TO_TICK(time) howmany((time), 30)
    299 #define PIO_REC_OFFSET 4
    300 #define PIO_REC_MIN 1
    301 #define PIO_ACT_MIN 1
    302 #define DMA_REC_OFFSET 1
    303 #define DMA_REC_MIN 1
    304 #define DMA_ACT_MIN 1
    305 
    306 #define ATA4_TIME_TO_TICK(time)  howmany((time), 15) /* 15 ns clock */
    307 
    308 #define CONFIG_REG (0x200)		/* IDE access timing register */
    309 
    310 void
    311 wdc_obio_select(chp, drive)
    312 	struct ata_channel *chp;
    313 	int drive;
    314 {
    315 	struct wdc_obio_softc *sc = (struct wdc_obio_softc *)chp->ch_atac;
    316 	struct wdc_regs *wdr = CHAN_TO_WDC_REGS(chp);
    317 
    318 	bus_space_write_4(wdr->cmd_iot, wdr->cmd_baseioh,
    319 			CONFIG_REG, sc->sc_dmaconf[drive]);
    320 }
    321 
    322 void
    323 adjust_timing(chp)
    324 	struct ata_channel *chp;
    325 {
    326 	struct wdc_obio_softc *sc = (struct wdc_obio_softc *)chp->ch_atac;
    327 	int drive;
    328 	int min_cycle = 0, min_active = 0;
    329 	int cycle_tick = 0, act_tick = 0, inact_tick = 0, half_tick;
    330 
    331 	for (drive = 0; drive < 2; drive++) {
    332 		u_int conf = 0;
    333 		struct ata_drive_datas *drvp;
    334 
    335 		drvp = &chp->ch_drive[drive];
    336 		/* set up pio mode timings */
    337 		if (drvp->drive_flags & DRIVE) {
    338 			int piomode = drvp->PIO_mode;
    339 			min_cycle = pio_timing[piomode].cycle;
    340 			min_active = pio_timing[piomode].active;
    341 
    342 			cycle_tick = TIME_TO_TICK(min_cycle);
    343 			act_tick = TIME_TO_TICK(min_active);
    344 			if (act_tick < PIO_ACT_MIN)
    345 				act_tick = PIO_ACT_MIN;
    346 			inact_tick = cycle_tick - act_tick - PIO_REC_OFFSET;
    347 			if (inact_tick < PIO_REC_MIN)
    348 				inact_tick = PIO_REC_MIN;
    349 			/* mask: 0x000007ff */
    350 			conf |= (inact_tick << 5) | act_tick;
    351 		}
    352 		/* Set up DMA mode timings */
    353 		if (drvp->drive_flags & DRIVE_DMA) {
    354 			int dmamode = drvp->DMA_mode;
    355 			min_cycle = dma_timing[dmamode].cycle;
    356 			min_active = dma_timing[dmamode].active;
    357 			cycle_tick = TIME_TO_TICK(min_cycle);
    358 			act_tick = TIME_TO_TICK(min_active);
    359 			inact_tick = cycle_tick - act_tick - DMA_REC_OFFSET;
    360 			if (inact_tick < DMA_REC_MIN)
    361 				inact_tick = DMA_REC_MIN;
    362 			half_tick = 0;	/* XXX */
    363 			/* mask: 0xfffff800 */
    364 			conf |=
    365 					(half_tick << 21) |
    366 					(inact_tick << 16) | (act_tick << 11);
    367 		}
    368 #ifdef DEBUG
    369 		if (conf) {
    370 			printf("conf[%d] = 0x%x, cyc = %d (%d ns), act = %d (%d ns), inact = %d\n",
    371 					drive, conf, cycle_tick, min_cycle, act_tick, min_active, inact_tick);
    372 		}
    373 #endif
    374 		sc->sc_dmaconf[drive] = conf;
    375 	}
    376 	sc->sc_wdcdev.select = 0;
    377 	if (sc->sc_dmaconf[0]) {
    378 		wdc_obio_select(chp,0);
    379 		if (sc->sc_dmaconf[1] &&
    380 		    (sc->sc_dmaconf[0] != sc->sc_dmaconf[1])) {
    381 			sc->sc_wdcdev.select = wdc_obio_select;
    382 		}
    383 	} else if (sc->sc_dmaconf[1]) {
    384 		wdc_obio_select(chp,1);
    385 	}
    386 }
    387 
    388 void
    389 ata4_adjust_timing(chp)
    390 	struct ata_channel *chp;
    391 {
    392 	struct wdc_obio_softc *sc = (struct wdc_obio_softc *)chp->ch_atac;
    393 	int drive;
    394 	int min_cycle = 0, min_active = 0;
    395 	int cycle_tick = 0, act_tick = 0, inact_tick = 0;
    396 
    397 	for (drive = 0; drive < 2; drive++) {
    398 		u_int conf = 0;
    399 		struct ata_drive_datas *drvp;
    400 
    401 		drvp = &chp->ch_drive[drive];
    402 		/* set up pio mode timings */
    403 
    404 		if (drvp->drive_flags & DRIVE) {
    405 			int piomode = drvp->PIO_mode;
    406 			min_cycle = pio_timing[piomode].cycle;
    407 			min_active = pio_timing[piomode].active;
    408 
    409 			cycle_tick = ATA4_TIME_TO_TICK(min_cycle);
    410 			act_tick = ATA4_TIME_TO_TICK(min_active);
    411 			inact_tick = cycle_tick - act_tick;
    412 			/* mask: 0x000003ff */
    413 			conf |= (inact_tick << 5) | act_tick;
    414 		}
    415 		/* set up dma mode timings */
    416 		if (drvp->drive_flags & DRIVE_DMA) {
    417 			int dmamode = drvp->DMA_mode;
    418 			min_cycle = dma_timing[dmamode].cycle;
    419 			min_active = dma_timing[dmamode].active;
    420 			cycle_tick = ATA4_TIME_TO_TICK(min_cycle);
    421 			act_tick = ATA4_TIME_TO_TICK(min_active);
    422 			inact_tick = cycle_tick - act_tick;
    423 			/* mask: 0x001ffc00 */
    424 			conf |= (act_tick << 10) | (inact_tick << 15);
    425 		}
    426 		/* set up udma mode timings */
    427 		if (drvp->drive_flags & DRIVE_UDMA) {
    428 			int udmamode = drvp->UDMA_mode;
    429 			min_cycle = udma_timing[udmamode].cycle;
    430 			min_active = udma_timing[udmamode].active;
    431 			act_tick = ATA4_TIME_TO_TICK(min_active);
    432 			cycle_tick = ATA4_TIME_TO_TICK(min_cycle);
    433 			/* mask: 0x1ff00000 */
    434 			conf |= (cycle_tick << 21) | (act_tick << 25) | 0x100000;
    435 		}
    436 #ifdef DEBUG
    437 		if (conf) {
    438 			printf("ata4 conf[%d] = 0x%x, cyc = %d (%d ns), act = %d (%d ns), inact = %d\n",
    439 					drive, conf, cycle_tick, min_cycle, act_tick, min_active, inact_tick);
    440 		}
    441 #endif
    442 		sc->sc_dmaconf[drive] = conf;
    443 	}
    444 	sc->sc_wdcdev.select = 0;
    445 	if (sc->sc_dmaconf[0]) {
    446 		wdc_obio_select(chp,0);
    447 		if (sc->sc_dmaconf[1] &&
    448 		    (sc->sc_dmaconf[0] != sc->sc_dmaconf[1])) {
    449 			sc->sc_wdcdev.select = wdc_obio_select;
    450 		}
    451 	} else if (sc->sc_dmaconf[1]) {
    452 		wdc_obio_select(chp,1);
    453 	}
    454 }
    455 
    456 int
    457 wdc_obio_detach(self, flags)
    458 	struct device *self;
    459 	int flags;
    460 {
    461 	struct wdc_obio_softc *sc = (void *)self;
    462 	int error;
    463 
    464 	if ((error = wdcdetach(self, flags)) != 0)
    465 		return error;
    466 
    467 	intr_disestablish(sc->sc_ih);
    468 
    469 	/* Unmap our i/o space. */
    470 	bus_space_unmap(sc->sc_wdcdev.regs->cmd_iot,
    471 			sc->sc_wdcdev.regs->cmd_baseioh, WDC_REG_NPORTS << 4);
    472 
    473 	/* Unmap DMA registers. */
    474 	/* XXX unmapiodev(sc->sc_dmareg); */
    475 	/* XXX free(sc->sc_dmacmd); */
    476 
    477 	return 0;
    478 }
    479 
    480 int
    481 wdc_obio_dma_init(v, channel, drive, databuf, datalen, flags)
    482 	void *v;
    483 	void *databuf;
    484 	size_t datalen;
    485 	int flags;
    486 {
    487 	struct wdc_obio_softc *sc = v;
    488 	vaddr_t va = (vaddr_t)databuf;
    489 	dbdma_command_t *cmdp;
    490 	u_int cmd, offset;
    491 	int read = flags & WDC_DMA_READ;
    492 
    493 	cmdp = sc->sc_dmacmd;
    494 	cmd = read ? DBDMA_CMD_IN_MORE : DBDMA_CMD_OUT_MORE;
    495 
    496 	offset = va & PGOFSET;
    497 
    498 	/* if va is not page-aligned, setup the first page */
    499 	if (offset != 0) {
    500 		int rest = PAGE_SIZE - offset;	/* the rest of the page */
    501 
    502 		if (datalen > rest) {		/* if continues to next page */
    503 			DBDMA_BUILD(cmdp, cmd, 0, rest, vtophys(va),
    504 				DBDMA_INT_NEVER, DBDMA_WAIT_NEVER,
    505 				DBDMA_BRANCH_NEVER);
    506 			datalen -= rest;
    507 			va += rest;
    508 			cmdp++;
    509 		}
    510 	}
    511 
    512 	/* now va is page-aligned */
    513 	while (datalen > PAGE_SIZE) {
    514 		DBDMA_BUILD(cmdp, cmd, 0, PAGE_SIZE, vtophys(va),
    515 			DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
    516 		datalen -= PAGE_SIZE;
    517 		va += PAGE_SIZE;
    518 		cmdp++;
    519 	}
    520 
    521 	/* the last page (datalen <= PAGE_SIZE here) */
    522 	cmd = read ? DBDMA_CMD_IN_LAST : DBDMA_CMD_OUT_LAST;
    523 	DBDMA_BUILD(cmdp, cmd, 0, datalen, vtophys(va),
    524 		DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
    525 	cmdp++;
    526 
    527 	DBDMA_BUILD(cmdp, DBDMA_CMD_STOP, 0, 0, 0,
    528 		DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
    529 
    530 	return 0;
    531 }
    532 
    533 void
    534 wdc_obio_dma_start(v, channel, drive)
    535 	void *v;
    536 	int channel, drive;
    537 {
    538 	struct wdc_obio_softc *sc = v;
    539 
    540 	dbdma_start(sc->sc_dmareg, sc->sc_dmacmd);
    541 }
    542 
    543 int
    544 wdc_obio_dma_finish(v, channel, drive, read)
    545 	void *v;
    546 	int channel, drive;
    547 	int read;
    548 {
    549 	struct wdc_obio_softc *sc = v;
    550 
    551 	dbdma_stop(sc->sc_dmareg);
    552 	return 0;
    553 }
    554