xref: /freebsd/sys/arm/broadcom/bcm2835/bcm2835_sdhci.c (revision 545ddfbe7d4fe8adfb862903b24eac1d5896c1ef)
1 /*-
2  * Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  */
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bio.h>
33 #include <sys/bus.h>
34 #include <sys/conf.h>
35 #include <sys/endian.h>
36 #include <sys/kernel.h>
37 #include <sys/kthread.h>
38 #include <sys/lock.h>
39 #include <sys/malloc.h>
40 #include <sys/module.h>
41 #include <sys/mutex.h>
42 #include <sys/queue.h>
43 #include <sys/resource.h>
44 #include <sys/rman.h>
45 #include <sys/sysctl.h>
46 #include <sys/taskqueue.h>
47 #include <sys/time.h>
48 #include <sys/timetc.h>
49 #include <sys/watchdog.h>
50 
51 #include <sys/kdb.h>
52 
53 #include <machine/bus.h>
54 #include <machine/cpu.h>
55 #include <machine/cpufunc.h>
56 #include <machine/resource.h>
57 #include <machine/intr.h>
58 
59 #include <dev/fdt/fdt_common.h>
60 #include <dev/ofw/ofw_bus.h>
61 #include <dev/ofw/ofw_bus_subr.h>
62 
63 #include <dev/mmc/bridge.h>
64 #include <dev/mmc/mmcreg.h>
65 #include <dev/mmc/mmcbrvar.h>
66 
67 #include <dev/sdhci/sdhci.h>
68 #include "sdhci_if.h"
69 
70 #include "bcm2835_dma.h"
71 #include "bcm2835_vcbus.h"
72 
73 #define	BCM2835_DEFAULT_SDHCI_FREQ	50
74 
75 #define	BCM_SDHCI_BUFFER_SIZE		512
76 #define	NUM_DMA_SEGS			2
77 
78 #ifdef DEBUG
79 #define dprintf(fmt, args...) do { printf("%s(): ", __func__);   \
80     printf(fmt,##args); } while (0)
81 #else
82 #define dprintf(fmt, args...)
83 #endif
84 
85 /*
86  * Arasan HC seems to have problem with Data CRC on lower frequencies.
87  * Use this tunable to cap initialization sequence frequency at higher
88  * value.  Default is standard 400kHz.
89  * HS mode brings too many problems for most of cards, so disable HS mode
90  * until a better fix comes up.
91  * HS mode still can be enabled with the tunable.
92  */
93 static int bcm2835_sdhci_min_freq = 400000;
94 static int bcm2835_sdhci_hs = 1;
95 static int bcm2835_sdhci_pio_mode = 0;
96 
97 TUNABLE_INT("hw.bcm2835.sdhci.min_freq", &bcm2835_sdhci_min_freq);
98 TUNABLE_INT("hw.bcm2835.sdhci.hs", &bcm2835_sdhci_hs);
99 TUNABLE_INT("hw.bcm2835.sdhci.pio_mode", &bcm2835_sdhci_pio_mode);
100 
101 struct bcm_sdhci_softc {
102 	device_t		sc_dev;
103 	struct mtx		sc_mtx;
104 	struct resource *	sc_mem_res;
105 	struct resource *	sc_irq_res;
106 	bus_space_tag_t		sc_bst;
107 	bus_space_handle_t	sc_bsh;
108 	void *			sc_intrhand;
109 	struct mmc_request *	sc_req;
110 	struct mmc_data *	sc_data;
111 	uint32_t		sc_flags;
112 #define	LPC_SD_FLAGS_IGNORECRC		(1 << 0)
113 	int			sc_xfer_direction;
114 #define	DIRECTION_READ		0
115 #define	DIRECTION_WRITE		1
116 	int			sc_xfer_done;
117 	int			sc_bus_busy;
118 	struct sdhci_slot	sc_slot;
119 	int			sc_dma_inuse;
120 	int			sc_dma_ch;
121 	bus_dma_tag_t		sc_dma_tag;
122 	bus_dmamap_t		sc_dma_map;
123 	vm_paddr_t		sc_sdhci_buffer_phys;
124 	uint32_t		cmd_and_mode;
125 	bus_addr_t		dmamap_seg_addrs[NUM_DMA_SEGS];
126 	bus_size_t		dmamap_seg_sizes[NUM_DMA_SEGS];
127 	int			dmamap_seg_count;
128 	int			dmamap_seg_index;
129 	int			dmamap_status;
130 };
131 
132 static int bcm_sdhci_probe(device_t);
133 static int bcm_sdhci_attach(device_t);
134 static int bcm_sdhci_detach(device_t);
135 static void bcm_sdhci_intr(void *);
136 
137 static int bcm_sdhci_get_ro(device_t, device_t);
138 static void bcm_sdhci_dma_intr(int ch, void *arg);
139 
140 #define	bcm_sdhci_lock(_sc)						\
141     mtx_lock(&_sc->sc_mtx);
142 #define	bcm_sdhci_unlock(_sc)						\
143     mtx_unlock(&_sc->sc_mtx);
144 
145 static void
146 bcm_sdhci_dmacb(void *arg, bus_dma_segment_t *segs, int nseg, int err)
147 {
148 	struct bcm_sdhci_softc *sc = arg;
149 	int i;
150 
151 	sc->dmamap_status = err;
152 	sc->dmamap_seg_count = nseg;
153 
154 	/* Note nseg is guaranteed to be zero if err is non-zero. */
155 	for (i = 0; i < nseg; i++) {
156 		sc->dmamap_seg_addrs[i] = segs[i].ds_addr;
157 		sc->dmamap_seg_sizes[i] = segs[i].ds_len;
158 	}
159 }
160 
161 static int
162 bcm_sdhci_probe(device_t dev)
163 {
164 
165 	if (!ofw_bus_status_okay(dev))
166 		return (ENXIO);
167 
168 	if (!ofw_bus_is_compatible(dev, "broadcom,bcm2835-sdhci"))
169 		return (ENXIO);
170 
171 	device_set_desc(dev, "Broadcom 2708 SDHCI controller");
172 	return (BUS_PROBE_DEFAULT);
173 }
174 
175 static int
176 bcm_sdhci_attach(device_t dev)
177 {
178 	struct bcm_sdhci_softc *sc = device_get_softc(dev);
179 	int rid, err;
180 	phandle_t node;
181 	pcell_t cell;
182 	int default_freq;
183 
184 	sc->sc_dev = dev;
185 	sc->sc_req = NULL;
186 	err = 0;
187 
188 	default_freq = BCM2835_DEFAULT_SDHCI_FREQ;
189 	node = ofw_bus_get_node(sc->sc_dev);
190 	if ((OF_getprop(node, "clock-frequency", &cell, sizeof(cell))) > 0)
191 		default_freq = (int)fdt32_to_cpu(cell)/1000000;
192 
193 	dprintf("SDHCI frequency: %dMHz\n", default_freq);
194 
195 	mtx_init(&sc->sc_mtx, "bcm sdhci", "sdhci", MTX_DEF);
196 
197 	rid = 0;
198 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
199 	    RF_ACTIVE);
200 	if (!sc->sc_mem_res) {
201 		device_printf(dev, "cannot allocate memory window\n");
202 		err = ENXIO;
203 		goto fail;
204 	}
205 
206 	sc->sc_bst = rman_get_bustag(sc->sc_mem_res);
207 	sc->sc_bsh = rman_get_bushandle(sc->sc_mem_res);
208 
209 	rid = 0;
210 	sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
211 	    RF_ACTIVE);
212 	if (!sc->sc_irq_res) {
213 		device_printf(dev, "cannot allocate interrupt\n");
214 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
215 		err = ENXIO;
216 		goto fail;
217 	}
218 
219 	if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_BIO | INTR_MPSAFE,
220 	    NULL, bcm_sdhci_intr, sc, &sc->sc_intrhand))
221 	{
222 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
223 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
224 		device_printf(dev, "cannot setup interrupt handler\n");
225 		err = ENXIO;
226 		goto fail;
227 	}
228 
229 	if (!bcm2835_sdhci_pio_mode)
230 		sc->sc_slot.opt = SDHCI_PLATFORM_TRANSFER;
231 
232 	sc->sc_slot.caps = SDHCI_CAN_VDD_330 | SDHCI_CAN_VDD_180;
233 	if (bcm2835_sdhci_hs)
234 		sc->sc_slot.caps |= SDHCI_CAN_DO_HISPD;
235 	sc->sc_slot.caps |= (default_freq << SDHCI_CLOCK_BASE_SHIFT);
236 	sc->sc_slot.quirks = SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK
237 		| SDHCI_QUIRK_BROKEN_TIMEOUT_VAL
238 		| SDHCI_QUIRK_DONT_SET_HISPD_BIT
239 		| SDHCI_QUIRK_MISSING_CAPS;
240 
241 	sdhci_init_slot(dev, &sc->sc_slot, 0);
242 
243 	sc->sc_dma_ch = bcm_dma_allocate(BCM_DMA_CH_FAST1);
244 	if (sc->sc_dma_ch == BCM_DMA_CH_INVALID)
245 		sc->sc_dma_ch = bcm_dma_allocate(BCM_DMA_CH_FAST2);
246 	if (sc->sc_dma_ch == BCM_DMA_CH_INVALID)
247 		sc->sc_dma_ch = bcm_dma_allocate(BCM_DMA_CH_ANY);
248 	if (sc->sc_dma_ch == BCM_DMA_CH_INVALID)
249 		goto fail;
250 
251 	bcm_dma_setup_intr(sc->sc_dma_ch, bcm_sdhci_dma_intr, sc);
252 
253 	/* Allocate bus_dma resources. */
254 	err = bus_dma_tag_create(bus_get_dma_tag(dev),
255 	    1, 0, BUS_SPACE_MAXADDR_32BIT,
256 	    BUS_SPACE_MAXADDR, NULL, NULL,
257 	    BCM_SDHCI_BUFFER_SIZE, NUM_DMA_SEGS, BCM_SDHCI_BUFFER_SIZE,
258 	    BUS_DMA_ALLOCNOW, NULL, NULL,
259 	    &sc->sc_dma_tag);
260 
261 	if (err) {
262 		device_printf(dev, "failed allocate DMA tag");
263 		goto fail;
264 	}
265 
266 	err = bus_dmamap_create(sc->sc_dma_tag, 0, &sc->sc_dma_map);
267 	if (err) {
268 		device_printf(dev, "bus_dmamap_create failed\n");
269 		goto fail;
270 	}
271 
272 	sc->sc_sdhci_buffer_phys = BUS_SPACE_PHYSADDR(sc->sc_mem_res,
273 	    SDHCI_BUFFER);
274 
275 	bus_generic_probe(dev);
276 	bus_generic_attach(dev);
277 
278 	sdhci_start_slot(&sc->sc_slot);
279 
280 	return (0);
281 
282 fail:
283 	if (sc->sc_intrhand)
284 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
285 	if (sc->sc_irq_res)
286 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
287 	if (sc->sc_mem_res)
288 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
289 
290 	return (err);
291 }
292 
293 static int
294 bcm_sdhci_detach(device_t dev)
295 {
296 
297 	return (EBUSY);
298 }
299 
300 static void
301 bcm_sdhci_intr(void *arg)
302 {
303 	struct bcm_sdhci_softc *sc = arg;
304 
305 	sdhci_generic_intr(&sc->sc_slot);
306 }
307 
308 static int
309 bcm_sdhci_get_ro(device_t bus, device_t child)
310 {
311 
312 	return (0);
313 }
314 
315 static inline uint32_t
316 RD4(struct bcm_sdhci_softc *sc, bus_size_t off)
317 {
318 	uint32_t val = bus_space_read_4(sc->sc_bst, sc->sc_bsh, off);
319 	return val;
320 }
321 
322 static inline void
323 WR4(struct bcm_sdhci_softc *sc, bus_size_t off, uint32_t val)
324 {
325 
326 	bus_space_write_4(sc->sc_bst, sc->sc_bsh, off, val);
327 	/*
328 	 * The Arasan HC has a bug where it may lose the content of
329 	 * consecutive writes to registers that are within two SD-card
330 	 * clock cycles of each other (a clock domain crossing problem).
331 	 */
332 	if (sc->sc_slot.clock > 0)
333 		DELAY(((2 * 1000000) / sc->sc_slot.clock) + 1);
334 }
335 
336 static uint8_t
337 bcm_sdhci_read_1(device_t dev, struct sdhci_slot *slot, bus_size_t off)
338 {
339 	struct bcm_sdhci_softc *sc = device_get_softc(dev);
340 	uint32_t val = RD4(sc, off & ~3);
341 
342 	return ((val >> (off & 3)*8) & 0xff);
343 }
344 
345 static uint16_t
346 bcm_sdhci_read_2(device_t dev, struct sdhci_slot *slot, bus_size_t off)
347 {
348 	struct bcm_sdhci_softc *sc = device_get_softc(dev);
349 	uint32_t val = RD4(sc, off & ~3);
350 
351 	/*
352 	 * Standard 32-bit handling of command and transfer mode.
353 	 */
354 	if (off == SDHCI_TRANSFER_MODE) {
355 		return (sc->cmd_and_mode >> 16);
356 	} else if (off == SDHCI_COMMAND_FLAGS) {
357 		return (sc->cmd_and_mode & 0x0000ffff);
358 	}
359 	return ((val >> (off & 3)*8) & 0xffff);
360 }
361 
362 static uint32_t
363 bcm_sdhci_read_4(device_t dev, struct sdhci_slot *slot, bus_size_t off)
364 {
365 	struct bcm_sdhci_softc *sc = device_get_softc(dev);
366 
367 	return RD4(sc, off);
368 }
369 
370 static void
371 bcm_sdhci_read_multi_4(device_t dev, struct sdhci_slot *slot, bus_size_t off,
372     uint32_t *data, bus_size_t count)
373 {
374 	struct bcm_sdhci_softc *sc = device_get_softc(dev);
375 
376 	bus_space_read_multi_4(sc->sc_bst, sc->sc_bsh, off, data, count);
377 }
378 
379 static void
380 bcm_sdhci_write_1(device_t dev, struct sdhci_slot *slot, bus_size_t off, uint8_t val)
381 {
382 	struct bcm_sdhci_softc *sc = device_get_softc(dev);
383 	uint32_t val32 = RD4(sc, off & ~3);
384 	val32 &= ~(0xff << (off & 3)*8);
385 	val32 |= (val << (off & 3)*8);
386 	WR4(sc, off & ~3, val32);
387 }
388 
389 static void
390 bcm_sdhci_write_2(device_t dev, struct sdhci_slot *slot, bus_size_t off, uint16_t val)
391 {
392 	struct bcm_sdhci_softc *sc = device_get_softc(dev);
393 	uint32_t val32;
394 	if (off == SDHCI_COMMAND_FLAGS)
395 		val32 = sc->cmd_and_mode;
396 	else
397 		val32 = RD4(sc, off & ~3);
398 	val32 &= ~(0xffff << (off & 3)*8);
399 	val32 |= (val << (off & 3)*8);
400 	if (off == SDHCI_TRANSFER_MODE)
401 		sc->cmd_and_mode = val32;
402 	else {
403 		WR4(sc, off & ~3, val32);
404 		if (off == SDHCI_COMMAND_FLAGS)
405 			sc->cmd_and_mode = val32;
406 	}
407 }
408 
409 static void
410 bcm_sdhci_write_4(device_t dev, struct sdhci_slot *slot, bus_size_t off, uint32_t val)
411 {
412 	struct bcm_sdhci_softc *sc = device_get_softc(dev);
413 	WR4(sc, off, val);
414 }
415 
416 static void
417 bcm_sdhci_write_multi_4(device_t dev, struct sdhci_slot *slot, bus_size_t off,
418     uint32_t *data, bus_size_t count)
419 {
420 	struct bcm_sdhci_softc *sc = device_get_softc(dev);
421 
422 	bus_space_write_multi_4(sc->sc_bst, sc->sc_bsh, off, data, count);
423 }
424 
425 static uint32_t
426 bcm_sdhci_min_freq(device_t dev, struct sdhci_slot *slot)
427 {
428 
429 	return bcm2835_sdhci_min_freq;
430 }
431 
432 static void
433 bcm_sdhci_start_dma_seg(struct bcm_sdhci_softc *sc)
434 {
435 	struct sdhci_slot *slot;
436 	vm_paddr_t pdst, psrc;
437 	int err, idx, len, sync_op;
438 
439 	slot = &sc->sc_slot;
440 	idx = sc->dmamap_seg_index++;
441 	len = sc->dmamap_seg_sizes[idx];
442 	slot->offset += len;
443 
444 	if (slot->curcmd->data->flags & MMC_DATA_READ) {
445 		bcm_dma_setup_src(sc->sc_dma_ch, BCM_DMA_DREQ_EMMC,
446 		    BCM_DMA_SAME_ADDR, BCM_DMA_32BIT);
447 		bcm_dma_setup_dst(sc->sc_dma_ch, BCM_DMA_DREQ_NONE,
448 		    BCM_DMA_INC_ADDR,
449 		    (len & 0xf) ? BCM_DMA_32BIT : BCM_DMA_128BIT);
450 		psrc = sc->sc_sdhci_buffer_phys;
451 		pdst = sc->dmamap_seg_addrs[idx];
452 		sync_op = BUS_DMASYNC_PREREAD;
453 	} else {
454 		bcm_dma_setup_src(sc->sc_dma_ch, BCM_DMA_DREQ_NONE,
455 		    BCM_DMA_INC_ADDR,
456 		    (len & 0xf) ? BCM_DMA_32BIT : BCM_DMA_128BIT);
457 		bcm_dma_setup_dst(sc->sc_dma_ch, BCM_DMA_DREQ_EMMC,
458 		    BCM_DMA_SAME_ADDR, BCM_DMA_32BIT);
459 		psrc = sc->dmamap_seg_addrs[idx];
460 		pdst = sc->sc_sdhci_buffer_phys;
461 		sync_op = BUS_DMASYNC_PREWRITE;
462 	}
463 
464 	/*
465 	 * When starting a new DMA operation do the busdma sync operation, and
466 	 * disable SDCHI data interrrupts because we'll be driven by DMA
467 	 * interrupts (or SDHCI error interrupts) until the IO is done.
468 	 */
469 	if (idx == 0) {
470 		bus_dmamap_sync(sc->sc_dma_tag, sc->sc_dma_map, sync_op);
471 		slot->intmask &= ~(SDHCI_INT_DATA_AVAIL |
472 		    SDHCI_INT_SPACE_AVAIL | SDHCI_INT_DATA_END);
473 		bcm_sdhci_write_4(sc->sc_dev, &sc->sc_slot, SDHCI_SIGNAL_ENABLE,
474 		    slot->intmask);
475 	}
476 
477 	/*
478 	 * Start the DMA transfer.  Only programming errors (like failing to
479 	 * allocate a channel) cause a non-zero return from bcm_dma_start().
480 	 */
481 	err = bcm_dma_start(sc->sc_dma_ch, psrc, pdst, len);
482 	KASSERT((err == 0), ("bcm2835_sdhci: failed DMA start"));
483 }
484 
485 static void
486 bcm_sdhci_dma_intr(int ch, void *arg)
487 {
488 	struct bcm_sdhci_softc *sc = (struct bcm_sdhci_softc *)arg;
489 	struct sdhci_slot *slot = &sc->sc_slot;
490 	uint32_t reg, mask;
491 	int left, sync_op;
492 
493 	mtx_lock(&slot->mtx);
494 
495 	/*
496 	 * If there are more segments for the current dma, start the next one.
497 	 * Otherwise unload the dma map and decide what to do next based on the
498 	 * status of the sdhci controller and whether there's more data left.
499 	 */
500 	if (sc->dmamap_seg_index < sc->dmamap_seg_count) {
501 		bcm_sdhci_start_dma_seg(sc);
502 		mtx_unlock(&slot->mtx);
503 		return;
504 	}
505 
506 	if (slot->curcmd->data->flags & MMC_DATA_READ) {
507 		sync_op = BUS_DMASYNC_POSTREAD;
508 		mask = SDHCI_INT_DATA_AVAIL;
509 	} else {
510 		sync_op = BUS_DMASYNC_POSTWRITE;
511 		mask = SDHCI_INT_SPACE_AVAIL;
512 	}
513 	bus_dmamap_sync(sc->sc_dma_tag, sc->sc_dma_map, sync_op);
514 	bus_dmamap_unload(sc->sc_dma_tag, sc->sc_dma_map);
515 
516 	sc->dmamap_seg_count = 0;
517 	sc->dmamap_seg_index = 0;
518 
519 	left = min(BCM_SDHCI_BUFFER_SIZE,
520 	    slot->curcmd->data->len - slot->offset);
521 
522 	/* DATA END? */
523 	reg = bcm_sdhci_read_4(slot->bus, slot, SDHCI_INT_STATUS);
524 
525 	if (reg & SDHCI_INT_DATA_END) {
526 		/* ACK for all outstanding interrupts */
527 		bcm_sdhci_write_4(slot->bus, slot, SDHCI_INT_STATUS, reg);
528 
529 		/* enable INT */
530 		slot->intmask |= SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL
531 		    | SDHCI_INT_DATA_END;
532 		bcm_sdhci_write_4(slot->bus, slot, SDHCI_SIGNAL_ENABLE,
533 		    slot->intmask);
534 
535 		/* finish this data */
536 		sdhci_finish_data(slot);
537 	}
538 	else {
539 		/* already available? */
540 		if (reg & mask) {
541 
542 			/* ACK for DATA_AVAIL or SPACE_AVAIL */
543 			bcm_sdhci_write_4(slot->bus, slot,
544 			    SDHCI_INT_STATUS, mask);
545 
546 			/* continue next DMA transfer */
547 			if (bus_dmamap_load(sc->sc_dma_tag, sc->sc_dma_map,
548 			    (uint8_t *)slot->curcmd->data->data +
549 			    slot->offset, left, bcm_sdhci_dmacb, sc,
550 			    BUS_DMA_NOWAIT) != 0 || sc->dmamap_status != 0) {
551 				slot->curcmd->error = MMC_ERR_NO_MEMORY;
552 				sdhci_finish_data(slot);
553 			} else {
554 				bcm_sdhci_start_dma_seg(sc);
555 			}
556 		} else {
557 			/* wait for next data by INT */
558 
559 			/* enable INT */
560 			slot->intmask |= SDHCI_INT_DATA_AVAIL |
561 			    SDHCI_INT_SPACE_AVAIL | SDHCI_INT_DATA_END;
562 			bcm_sdhci_write_4(slot->bus, slot, SDHCI_SIGNAL_ENABLE,
563 			    slot->intmask);
564 		}
565 	}
566 
567 	mtx_unlock(&slot->mtx);
568 }
569 
570 static void
571 bcm_sdhci_read_dma(device_t dev, struct sdhci_slot *slot)
572 {
573 	struct bcm_sdhci_softc *sc = device_get_softc(slot->bus);
574 	size_t left;
575 
576 	if (sc->dmamap_seg_count != 0) {
577 		device_printf(sc->sc_dev, "DMA in use\n");
578 		return;
579 	}
580 
581 	left = min(BCM_SDHCI_BUFFER_SIZE,
582 	    slot->curcmd->data->len - slot->offset);
583 
584 	KASSERT((left & 3) == 0,
585 	    ("%s: len = %d, not word-aligned", __func__, left));
586 
587 	if (bus_dmamap_load(sc->sc_dma_tag, sc->sc_dma_map,
588 	    (uint8_t *)slot->curcmd->data->data + slot->offset, left,
589 	    bcm_sdhci_dmacb, sc, BUS_DMA_NOWAIT) != 0 ||
590 	    sc->dmamap_status != 0) {
591 		slot->curcmd->error = MMC_ERR_NO_MEMORY;
592 		return;
593 	}
594 
595 	/* DMA start */
596 	bcm_sdhci_start_dma_seg(sc);
597 }
598 
599 static void
600 bcm_sdhci_write_dma(device_t dev, struct sdhci_slot *slot)
601 {
602 	struct bcm_sdhci_softc *sc = device_get_softc(slot->bus);
603 	size_t left;
604 
605 	if (sc->dmamap_seg_count != 0) {
606 		device_printf(sc->sc_dev, "DMA in use\n");
607 		return;
608 	}
609 
610 	left = min(BCM_SDHCI_BUFFER_SIZE,
611 	    slot->curcmd->data->len - slot->offset);
612 
613 	KASSERT((left & 3) == 0,
614 	    ("%s: len = %d, not word-aligned", __func__, left));
615 
616 	if (bus_dmamap_load(sc->sc_dma_tag, sc->sc_dma_map,
617 	    (uint8_t *)slot->curcmd->data->data + slot->offset, left,
618 	    bcm_sdhci_dmacb, sc, BUS_DMA_NOWAIT) != 0 ||
619 	    sc->dmamap_status != 0) {
620 		slot->curcmd->error = MMC_ERR_NO_MEMORY;
621 		return;
622 	}
623 
624 	/* DMA start */
625 	bcm_sdhci_start_dma_seg(sc);
626 }
627 
628 static int
629 bcm_sdhci_will_handle_transfer(device_t dev, struct sdhci_slot *slot)
630 {
631 	size_t left;
632 
633 	/*
634 	 * Do not use DMA for transfers less than block size or with a length
635 	 * that is not a multiple of four.
636 	 */
637 	left = min(BCM_DMA_BLOCK_SIZE,
638 	    slot->curcmd->data->len - slot->offset);
639 	if (left < BCM_DMA_BLOCK_SIZE)
640 		return (0);
641 	if (left & 0x03)
642 		return (0);
643 
644 	return (1);
645 }
646 
647 static void
648 bcm_sdhci_start_transfer(device_t dev, struct sdhci_slot *slot,
649     uint32_t *intmask)
650 {
651 
652 	/* DMA transfer FIFO 1KB */
653 	if (slot->curcmd->data->flags & MMC_DATA_READ)
654 		bcm_sdhci_read_dma(dev, slot);
655 	else
656 		bcm_sdhci_write_dma(dev, slot);
657 }
658 
659 static void
660 bcm_sdhci_finish_transfer(device_t dev, struct sdhci_slot *slot)
661 {
662 
663 	sdhci_finish_data(slot);
664 }
665 
666 static device_method_t bcm_sdhci_methods[] = {
667 	/* Device interface */
668 	DEVMETHOD(device_probe,		bcm_sdhci_probe),
669 	DEVMETHOD(device_attach,	bcm_sdhci_attach),
670 	DEVMETHOD(device_detach,	bcm_sdhci_detach),
671 
672 	/* Bus interface */
673 	DEVMETHOD(bus_read_ivar,	sdhci_generic_read_ivar),
674 	DEVMETHOD(bus_write_ivar,	sdhci_generic_write_ivar),
675 	DEVMETHOD(bus_print_child,	bus_generic_print_child),
676 
677 	/* MMC bridge interface */
678 	DEVMETHOD(mmcbr_update_ios,	sdhci_generic_update_ios),
679 	DEVMETHOD(mmcbr_request,	sdhci_generic_request),
680 	DEVMETHOD(mmcbr_get_ro,		bcm_sdhci_get_ro),
681 	DEVMETHOD(mmcbr_acquire_host,	sdhci_generic_acquire_host),
682 	DEVMETHOD(mmcbr_release_host,	sdhci_generic_release_host),
683 
684 	DEVMETHOD(sdhci_min_freq,	bcm_sdhci_min_freq),
685 	/* Platform transfer methods */
686 	DEVMETHOD(sdhci_platform_will_handle,		bcm_sdhci_will_handle_transfer),
687 	DEVMETHOD(sdhci_platform_start_transfer,	bcm_sdhci_start_transfer),
688 	DEVMETHOD(sdhci_platform_finish_transfer,	bcm_sdhci_finish_transfer),
689 	/* SDHCI registers accessors */
690 	DEVMETHOD(sdhci_read_1,		bcm_sdhci_read_1),
691 	DEVMETHOD(sdhci_read_2,		bcm_sdhci_read_2),
692 	DEVMETHOD(sdhci_read_4,		bcm_sdhci_read_4),
693 	DEVMETHOD(sdhci_read_multi_4,	bcm_sdhci_read_multi_4),
694 	DEVMETHOD(sdhci_write_1,	bcm_sdhci_write_1),
695 	DEVMETHOD(sdhci_write_2,	bcm_sdhci_write_2),
696 	DEVMETHOD(sdhci_write_4,	bcm_sdhci_write_4),
697 	DEVMETHOD(sdhci_write_multi_4,	bcm_sdhci_write_multi_4),
698 
699 	{ 0, 0 }
700 };
701 
702 static devclass_t bcm_sdhci_devclass;
703 
704 static driver_t bcm_sdhci_driver = {
705 	"sdhci_bcm",
706 	bcm_sdhci_methods,
707 	sizeof(struct bcm_sdhci_softc),
708 };
709 
710 DRIVER_MODULE(sdhci_bcm, simplebus, bcm_sdhci_driver, bcm_sdhci_devclass, 0, 0);
711 MODULE_DEPEND(sdhci_bcm, sdhci, 1, 1, 1);
712