xref: /linux/drivers/ssb/sdio.c (revision 217188d9f985bd3ce8c9a0cd50ca35be62d0f8c6)
1 /*
2  * Sonics Silicon Backplane
3  * SDIO-Hostbus related functions
4  *
5  * Copyright 2009 Albert Herranz <albert_herranz@yahoo.es>
6  *
7  * Based on drivers/ssb/pcmcia.c
8  * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
9  * Copyright 2007-2008 Michael Buesch <m@bues.ch>
10  *
11  * Licensed under the GNU/GPL. See COPYING for details.
12  *
13  */
14 
15 #include "ssb_private.h"
16 
17 #include <linux/ssb/ssb.h>
18 #include <linux/delay.h>
19 #include <linux/io.h>
20 #include <linux/etherdevice.h>
21 #include <linux/mmc/sdio_func.h>
22 
23 /* Define the following to 1 to enable a printk on each coreswitch. */
24 #define SSB_VERBOSE_SDIOCORESWITCH_DEBUG		0
25 
26 
27 /* Hardware invariants CIS tuples */
28 #define SSB_SDIO_CIS			0x80
29 #define  SSB_SDIO_CIS_SROMREV		0x00
30 #define  SSB_SDIO_CIS_ID		0x01
31 #define  SSB_SDIO_CIS_BOARDREV		0x02
32 #define  SSB_SDIO_CIS_PA		0x03
33 #define   SSB_SDIO_CIS_PA_PA0B0_LO	0
34 #define   SSB_SDIO_CIS_PA_PA0B0_HI	1
35 #define   SSB_SDIO_CIS_PA_PA0B1_LO	2
36 #define   SSB_SDIO_CIS_PA_PA0B1_HI	3
37 #define   SSB_SDIO_CIS_PA_PA0B2_LO	4
38 #define   SSB_SDIO_CIS_PA_PA0B2_HI	5
39 #define   SSB_SDIO_CIS_PA_ITSSI		6
40 #define   SSB_SDIO_CIS_PA_MAXPOW	7
41 #define  SSB_SDIO_CIS_OEMNAME		0x04
42 #define  SSB_SDIO_CIS_CCODE		0x05
43 #define  SSB_SDIO_CIS_ANTENNA		0x06
44 #define  SSB_SDIO_CIS_ANTGAIN		0x07
45 #define  SSB_SDIO_CIS_BFLAGS		0x08
46 #define  SSB_SDIO_CIS_LEDS		0x09
47 
48 #define CISTPL_FUNCE_LAN_NODE_ID        0x04	/* same as in PCMCIA */
49 
50 
51 /*
52  * Function 1 miscellaneous registers.
53  *
54  * Definitions match src/include/sbsdio.h from the
55  * Android Open Source Project
56  * http://android.git.kernel.org/?p=platform/system/wlan/broadcom.git
57  *
58  */
59 #define SBSDIO_FUNC1_SBADDRLOW	0x1000a	/* SB Address window Low (b15) */
60 #define SBSDIO_FUNC1_SBADDRMID	0x1000b	/* SB Address window Mid (b23-b16) */
61 #define SBSDIO_FUNC1_SBADDRHIGH	0x1000c	/* SB Address window High (b24-b31) */
62 
63 /* valid bits in SBSDIO_FUNC1_SBADDRxxx regs */
64 #define SBSDIO_SBADDRLOW_MASK	0x80	/* Valid address bits in SBADDRLOW */
65 #define SBSDIO_SBADDRMID_MASK	0xff	/* Valid address bits in SBADDRMID */
66 #define SBSDIO_SBADDRHIGH_MASK	0xff	/* Valid address bits in SBADDRHIGH */
67 
68 #define SBSDIO_SB_OFT_ADDR_MASK	0x7FFF	/* sb offset addr is <= 15 bits, 32k */
69 
70 /* REVISIT: this flag doesn't seem to matter */
71 #define SBSDIO_SB_ACCESS_2_4B_FLAG	0x8000	/* forces 32-bit SB access */
72 
73 
74 /*
75  * Address map within the SDIO function address space (128K).
76  *
77  *   Start   End     Description
78  *   ------- ------- ------------------------------------------
79  *   0x00000 0x0ffff selected backplane address window (64K)
80  *   0x10000 0x1ffff backplane control registers (max 64K)
81  *
82  * The current address window is configured by writing to registers
83  * SBADDRLOW, SBADDRMID and SBADDRHIGH.
84  *
85  * In order to access the contents of a 32-bit Silicon Backplane address
86  * the backplane address window must be first loaded with the highest
87  * 16 bits of the target address. Then, an access must be done to the
88  * SDIO function address space using the lower 15 bits of the address.
89  * Bit 15 of the address must be set when doing 32 bit accesses.
90  *
91  * 10987654321098765432109876543210
92  * WWWWWWWWWWWWWWWWW                 SB Address Window
93  *                 OOOOOOOOOOOOOOOO  Offset within SB Address Window
94  *                 a                 32-bit access flag
95  */
96 
97 
98 /*
99  * SSB I/O via SDIO.
100  *
101  * NOTE: SDIO address @addr is 17 bits long (SDIO address space is 128K).
102  */
103 
104 static inline struct device *ssb_sdio_dev(struct ssb_bus *bus)
105 {
106 	return &bus->host_sdio->dev;
107 }
108 
109 /* host claimed */
110 static int ssb_sdio_writeb(struct ssb_bus *bus, unsigned int addr, u8 val)
111 {
112 	int error = 0;
113 
114 	sdio_writeb(bus->host_sdio, val, addr, &error);
115 	if (unlikely(error)) {
116 		dev_dbg(ssb_sdio_dev(bus), "%08X <- %02x, error %d\n",
117 			addr, val, error);
118 	}
119 
120 	return error;
121 }
122 
123 #if 0
124 static u8 ssb_sdio_readb(struct ssb_bus *bus, unsigned int addr)
125 {
126 	u8 val;
127 	int error = 0;
128 
129 	val = sdio_readb(bus->host_sdio, addr, &error);
130 	if (unlikely(error)) {
131 		dev_dbg(ssb_sdio_dev(bus), "%08X -> %02x, error %d\n",
132 			addr, val, error);
133 	}
134 
135 	return val;
136 }
137 #endif
138 
139 /* host claimed */
140 static int ssb_sdio_set_sbaddr_window(struct ssb_bus *bus, u32 address)
141 {
142 	int error;
143 
144 	error = ssb_sdio_writeb(bus, SBSDIO_FUNC1_SBADDRLOW,
145 				(address >> 8) & SBSDIO_SBADDRLOW_MASK);
146 	if (error)
147 		goto out;
148 	error = ssb_sdio_writeb(bus, SBSDIO_FUNC1_SBADDRMID,
149 				(address >> 16) & SBSDIO_SBADDRMID_MASK);
150 	if (error)
151 		goto out;
152 	error = ssb_sdio_writeb(bus, SBSDIO_FUNC1_SBADDRHIGH,
153 				(address >> 24) & SBSDIO_SBADDRHIGH_MASK);
154 	if (error)
155 		goto out;
156 	bus->sdio_sbaddr = address;
157 out:
158 	if (error) {
159 		dev_dbg(ssb_sdio_dev(bus), "failed to set address window"
160 			" to 0x%08x, error %d\n", address, error);
161 	}
162 
163 	return error;
164 }
165 
166 /* for enumeration use only */
167 u32 ssb_sdio_scan_read32(struct ssb_bus *bus, u16 offset)
168 {
169 	u32 val;
170 	int error;
171 
172 	sdio_claim_host(bus->host_sdio);
173 	val = sdio_readl(bus->host_sdio, offset, &error);
174 	sdio_release_host(bus->host_sdio);
175 	if (unlikely(error)) {
176 		dev_dbg(ssb_sdio_dev(bus), "%04X:%04X > %08x, error %d\n",
177 			bus->sdio_sbaddr >> 16, offset, val, error);
178 	}
179 
180 	return val;
181 }
182 
183 /* for enumeration use only */
184 int ssb_sdio_scan_switch_coreidx(struct ssb_bus *bus, u8 coreidx)
185 {
186 	u32 sbaddr;
187 	int error;
188 
189 	sbaddr = (coreidx * SSB_CORE_SIZE) + SSB_ENUM_BASE;
190 	sdio_claim_host(bus->host_sdio);
191 	error = ssb_sdio_set_sbaddr_window(bus, sbaddr);
192 	sdio_release_host(bus->host_sdio);
193 	if (error) {
194 		dev_err(ssb_sdio_dev(bus), "failed to switch to core %u,"
195 			" error %d\n", coreidx, error);
196 		goto out;
197 	}
198 out:
199 	return error;
200 }
201 
202 /* host must be already claimed */
203 static int ssb_sdio_switch_core(struct ssb_bus *bus, struct ssb_device *dev)
204 {
205 	u8 coreidx = dev->core_index;
206 	u32 sbaddr;
207 	int error = 0;
208 
209 	sbaddr = (coreidx * SSB_CORE_SIZE) + SSB_ENUM_BASE;
210 	if (unlikely(bus->sdio_sbaddr != sbaddr)) {
211 #if SSB_VERBOSE_SDIOCORESWITCH_DEBUG
212 		dev_info(ssb_sdio_dev(bus),
213 			   "switching to %s core, index %d\n",
214 			   ssb_core_name(dev->id.coreid), coreidx);
215 #endif
216 		error = ssb_sdio_set_sbaddr_window(bus, sbaddr);
217 		if (error) {
218 			dev_dbg(ssb_sdio_dev(bus), "failed to switch to"
219 				" core %u, error %d\n", coreidx, error);
220 			goto out;
221 		}
222 		bus->mapped_device = dev;
223 	}
224 
225 out:
226 	return error;
227 }
228 
229 static u8 ssb_sdio_read8(struct ssb_device *dev, u16 offset)
230 {
231 	struct ssb_bus *bus = dev->bus;
232 	u8 val = 0xff;
233 	int error = 0;
234 
235 	sdio_claim_host(bus->host_sdio);
236 	if (unlikely(ssb_sdio_switch_core(bus, dev)))
237 		goto out;
238 	offset |= bus->sdio_sbaddr & 0xffff;
239 	offset &= SBSDIO_SB_OFT_ADDR_MASK;
240 	val = sdio_readb(bus->host_sdio, offset, &error);
241 	if (error) {
242 		dev_dbg(ssb_sdio_dev(bus), "%04X:%04X > %02x, error %d\n",
243 			bus->sdio_sbaddr >> 16, offset, val, error);
244 	}
245 out:
246 	sdio_release_host(bus->host_sdio);
247 
248 	return val;
249 }
250 
251 static u16 ssb_sdio_read16(struct ssb_device *dev, u16 offset)
252 {
253 	struct ssb_bus *bus = dev->bus;
254 	u16 val = 0xffff;
255 	int error = 0;
256 
257 	sdio_claim_host(bus->host_sdio);
258 	if (unlikely(ssb_sdio_switch_core(bus, dev)))
259 		goto out;
260 	offset |= bus->sdio_sbaddr & 0xffff;
261 	offset &= SBSDIO_SB_OFT_ADDR_MASK;
262 	val = sdio_readw(bus->host_sdio, offset, &error);
263 	if (error) {
264 		dev_dbg(ssb_sdio_dev(bus), "%04X:%04X > %04x, error %d\n",
265 			bus->sdio_sbaddr >> 16, offset, val, error);
266 	}
267 out:
268 	sdio_release_host(bus->host_sdio);
269 
270 	return val;
271 }
272 
273 static u32 ssb_sdio_read32(struct ssb_device *dev, u16 offset)
274 {
275 	struct ssb_bus *bus = dev->bus;
276 	u32 val = 0xffffffff;
277 	int error = 0;
278 
279 	sdio_claim_host(bus->host_sdio);
280 	if (unlikely(ssb_sdio_switch_core(bus, dev)))
281 		goto out;
282 	offset |= bus->sdio_sbaddr & 0xffff;
283 	offset &= SBSDIO_SB_OFT_ADDR_MASK;
284 	offset |= SBSDIO_SB_ACCESS_2_4B_FLAG;	/* 32 bit data access */
285 	val = sdio_readl(bus->host_sdio, offset, &error);
286 	if (error) {
287 		dev_dbg(ssb_sdio_dev(bus), "%04X:%04X > %08x, error %d\n",
288 			bus->sdio_sbaddr >> 16, offset, val, error);
289 	}
290 out:
291 	sdio_release_host(bus->host_sdio);
292 
293 	return val;
294 }
295 
296 #ifdef CONFIG_SSB_BLOCKIO
297 static void ssb_sdio_block_read(struct ssb_device *dev, void *buffer,
298 				  size_t count, u16 offset, u8 reg_width)
299 {
300 	size_t saved_count = count;
301 	struct ssb_bus *bus = dev->bus;
302 	int error = 0;
303 
304 	sdio_claim_host(bus->host_sdio);
305 	if (unlikely(ssb_sdio_switch_core(bus, dev))) {
306 		error = -EIO;
307 		memset(buffer, 0xff, count);
308 		goto err_out;
309 	}
310 	offset |= bus->sdio_sbaddr & 0xffff;
311 	offset &= SBSDIO_SB_OFT_ADDR_MASK;
312 
313 	switch (reg_width) {
314 	case sizeof(u8): {
315 		error = sdio_readsb(bus->host_sdio, buffer, offset, count);
316 		break;
317 	}
318 	case sizeof(u16): {
319 		WARN_ON(count & 1);
320 		error = sdio_readsb(bus->host_sdio, buffer, offset, count);
321 		break;
322 	}
323 	case sizeof(u32): {
324 		WARN_ON(count & 3);
325 		offset |= SBSDIO_SB_ACCESS_2_4B_FLAG;	/* 32 bit data access */
326 		error = sdio_readsb(bus->host_sdio, buffer, offset, count);
327 		break;
328 	}
329 	default:
330 		WARN_ON(1);
331 	}
332 	if (!error)
333 		goto out;
334 
335 err_out:
336 	dev_dbg(ssb_sdio_dev(bus), "%04X:%04X (width=%u, len=%zu), error %d\n",
337 		bus->sdio_sbaddr >> 16, offset, reg_width, saved_count, error);
338 out:
339 	sdio_release_host(bus->host_sdio);
340 }
341 #endif /* CONFIG_SSB_BLOCKIO */
342 
343 static void ssb_sdio_write8(struct ssb_device *dev, u16 offset, u8 val)
344 {
345 	struct ssb_bus *bus = dev->bus;
346 	int error = 0;
347 
348 	sdio_claim_host(bus->host_sdio);
349 	if (unlikely(ssb_sdio_switch_core(bus, dev)))
350 		goto out;
351 	offset |= bus->sdio_sbaddr & 0xffff;
352 	offset &= SBSDIO_SB_OFT_ADDR_MASK;
353 	sdio_writeb(bus->host_sdio, val, offset, &error);
354 	if (error) {
355 		dev_dbg(ssb_sdio_dev(bus), "%04X:%04X < %02x, error %d\n",
356 			bus->sdio_sbaddr >> 16, offset, val, error);
357 	}
358 out:
359 	sdio_release_host(bus->host_sdio);
360 }
361 
362 static void ssb_sdio_write16(struct ssb_device *dev, u16 offset, u16 val)
363 {
364 	struct ssb_bus *bus = dev->bus;
365 	int error = 0;
366 
367 	sdio_claim_host(bus->host_sdio);
368 	if (unlikely(ssb_sdio_switch_core(bus, dev)))
369 		goto out;
370 	offset |= bus->sdio_sbaddr & 0xffff;
371 	offset &= SBSDIO_SB_OFT_ADDR_MASK;
372 	sdio_writew(bus->host_sdio, val, offset, &error);
373 	if (error) {
374 		dev_dbg(ssb_sdio_dev(bus), "%04X:%04X < %04x, error %d\n",
375 			bus->sdio_sbaddr >> 16, offset, val, error);
376 	}
377 out:
378 	sdio_release_host(bus->host_sdio);
379 }
380 
381 static void ssb_sdio_write32(struct ssb_device *dev, u16 offset, u32 val)
382 {
383 	struct ssb_bus *bus = dev->bus;
384 	int error = 0;
385 
386 	sdio_claim_host(bus->host_sdio);
387 	if (unlikely(ssb_sdio_switch_core(bus, dev)))
388 		goto out;
389 	offset |= bus->sdio_sbaddr & 0xffff;
390 	offset &= SBSDIO_SB_OFT_ADDR_MASK;
391 	offset |= SBSDIO_SB_ACCESS_2_4B_FLAG;	/* 32 bit data access */
392 	sdio_writel(bus->host_sdio, val, offset, &error);
393 	if (error) {
394 		dev_dbg(ssb_sdio_dev(bus), "%04X:%04X < %08x, error %d\n",
395 			bus->sdio_sbaddr >> 16, offset, val, error);
396 	}
397 	if (bus->quirks & SSB_QUIRK_SDIO_READ_AFTER_WRITE32)
398 		sdio_readl(bus->host_sdio, 0, &error);
399 out:
400 	sdio_release_host(bus->host_sdio);
401 }
402 
403 #ifdef CONFIG_SSB_BLOCKIO
404 static void ssb_sdio_block_write(struct ssb_device *dev, const void *buffer,
405 				   size_t count, u16 offset, u8 reg_width)
406 {
407 	size_t saved_count = count;
408 	struct ssb_bus *bus = dev->bus;
409 	int error = 0;
410 
411 	sdio_claim_host(bus->host_sdio);
412 	if (unlikely(ssb_sdio_switch_core(bus, dev))) {
413 		error = -EIO;
414 		memset((void *)buffer, 0xff, count);
415 		goto err_out;
416 	}
417 	offset |= bus->sdio_sbaddr & 0xffff;
418 	offset &= SBSDIO_SB_OFT_ADDR_MASK;
419 
420 	switch (reg_width) {
421 	case sizeof(u8):
422 		error = sdio_writesb(bus->host_sdio, offset,
423 				     (void *)buffer, count);
424 		break;
425 	case sizeof(u16):
426 		WARN_ON(count & 1);
427 		error = sdio_writesb(bus->host_sdio, offset,
428 				     (void *)buffer, count);
429 		break;
430 	case sizeof(u32):
431 		WARN_ON(count & 3);
432 		offset |= SBSDIO_SB_ACCESS_2_4B_FLAG;	/* 32 bit data access */
433 		error = sdio_writesb(bus->host_sdio, offset,
434 				     (void *)buffer, count);
435 		break;
436 	default:
437 		WARN_ON(1);
438 	}
439 	if (!error)
440 		goto out;
441 
442 err_out:
443 	dev_dbg(ssb_sdio_dev(bus), "%04X:%04X (width=%u, len=%zu), error %d\n",
444 		bus->sdio_sbaddr >> 16, offset, reg_width, saved_count, error);
445 out:
446 	sdio_release_host(bus->host_sdio);
447 }
448 
449 #endif /* CONFIG_SSB_BLOCKIO */
450 
451 /* Not "static", as it's used in main.c */
452 const struct ssb_bus_ops ssb_sdio_ops = {
453 	.read8		= ssb_sdio_read8,
454 	.read16		= ssb_sdio_read16,
455 	.read32		= ssb_sdio_read32,
456 	.write8		= ssb_sdio_write8,
457 	.write16	= ssb_sdio_write16,
458 	.write32	= ssb_sdio_write32,
459 #ifdef CONFIG_SSB_BLOCKIO
460 	.block_read	= ssb_sdio_block_read,
461 	.block_write	= ssb_sdio_block_write,
462 #endif
463 };
464 
465 #define GOTO_ERROR_ON(condition, description) do {	\
466 	if (unlikely(condition)) {			\
467 		error_description = description;	\
468 		goto error;				\
469 	}						\
470   } while (0)
471 
472 int ssb_sdio_get_invariants(struct ssb_bus *bus,
473 			    struct ssb_init_invariants *iv)
474 {
475 	struct ssb_sprom *sprom = &iv->sprom;
476 	struct ssb_boardinfo *bi = &iv->boardinfo;
477 	const char *error_description = "none";
478 	struct sdio_func_tuple *tuple;
479 	void *mac;
480 
481 	memset(sprom, 0xFF, sizeof(*sprom));
482 	sprom->boardflags_lo = 0;
483 	sprom->boardflags_hi = 0;
484 
485 	tuple = bus->host_sdio->tuples;
486 	while (tuple) {
487 		switch (tuple->code) {
488 		case 0x22: /* extended function */
489 			switch (tuple->data[0]) {
490 			case CISTPL_FUNCE_LAN_NODE_ID:
491 				GOTO_ERROR_ON((tuple->size != 7) &&
492 					      (tuple->data[1] != 6),
493 					      "mac tpl size");
494 				/* fetch the MAC address. */
495 				mac = tuple->data + 2;
496 				memcpy(sprom->il0mac, mac, ETH_ALEN);
497 				memcpy(sprom->et1mac, mac, ETH_ALEN);
498 				break;
499 			default:
500 				break;
501 			}
502 			break;
503 		case 0x80: /* vendor specific tuple */
504 			switch (tuple->data[0]) {
505 			case SSB_SDIO_CIS_SROMREV:
506 				GOTO_ERROR_ON(tuple->size != 2,
507 					      "sromrev tpl size");
508 				sprom->revision = tuple->data[1];
509 				break;
510 			case SSB_SDIO_CIS_ID:
511 				GOTO_ERROR_ON((tuple->size != 5) &&
512 					      (tuple->size != 7),
513 					      "id tpl size");
514 				bi->vendor = tuple->data[1] |
515 					     (tuple->data[2]<<8);
516 				break;
517 			case SSB_SDIO_CIS_BOARDREV:
518 				GOTO_ERROR_ON(tuple->size != 2,
519 					      "boardrev tpl size");
520 				sprom->board_rev = tuple->data[1];
521 				break;
522 			case SSB_SDIO_CIS_PA:
523 				GOTO_ERROR_ON((tuple->size != 9) &&
524 					      (tuple->size != 10),
525 					      "pa tpl size");
526 				sprom->pa0b0 = tuple->data[1] |
527 					 ((u16)tuple->data[2] << 8);
528 				sprom->pa0b1 = tuple->data[3] |
529 					 ((u16)tuple->data[4] << 8);
530 				sprom->pa0b2 = tuple->data[5] |
531 					 ((u16)tuple->data[6] << 8);
532 				sprom->itssi_a = tuple->data[7];
533 				sprom->itssi_bg = tuple->data[7];
534 				sprom->maxpwr_a = tuple->data[8];
535 				sprom->maxpwr_bg = tuple->data[8];
536 				break;
537 			case SSB_SDIO_CIS_OEMNAME:
538 				/* Not present */
539 				break;
540 			case SSB_SDIO_CIS_CCODE:
541 				GOTO_ERROR_ON(tuple->size != 2,
542 					      "ccode tpl size");
543 				sprom->country_code = tuple->data[1];
544 				break;
545 			case SSB_SDIO_CIS_ANTENNA:
546 				GOTO_ERROR_ON(tuple->size != 2,
547 					      "ant tpl size");
548 				sprom->ant_available_a = tuple->data[1];
549 				sprom->ant_available_bg = tuple->data[1];
550 				break;
551 			case SSB_SDIO_CIS_ANTGAIN:
552 				GOTO_ERROR_ON(tuple->size != 2,
553 					      "antg tpl size");
554 				sprom->antenna_gain.a0 = tuple->data[1];
555 				sprom->antenna_gain.a1 = tuple->data[1];
556 				sprom->antenna_gain.a2 = tuple->data[1];
557 				sprom->antenna_gain.a3 = tuple->data[1];
558 				break;
559 			case SSB_SDIO_CIS_BFLAGS:
560 				GOTO_ERROR_ON((tuple->size != 3) &&
561 					      (tuple->size != 5),
562 					      "bfl tpl size");
563 				sprom->boardflags_lo = tuple->data[1] |
564 						 ((u16)tuple->data[2] << 8);
565 				break;
566 			case SSB_SDIO_CIS_LEDS:
567 				GOTO_ERROR_ON(tuple->size != 5,
568 					      "leds tpl size");
569 				sprom->gpio0 = tuple->data[1];
570 				sprom->gpio1 = tuple->data[2];
571 				sprom->gpio2 = tuple->data[3];
572 				sprom->gpio3 = tuple->data[4];
573 				break;
574 			default:
575 				break;
576 			}
577 			break;
578 		default:
579 			break;
580 		}
581 		tuple = tuple->next;
582 	}
583 
584 	return 0;
585 error:
586 	dev_err(ssb_sdio_dev(bus), "failed to fetch device invariants: %s\n",
587 		error_description);
588 	return -ENODEV;
589 }
590 
591 void ssb_sdio_exit(struct ssb_bus *bus)
592 {
593 	if (bus->bustype != SSB_BUSTYPE_SDIO)
594 		return;
595 	/* Nothing to do here. */
596 }
597 
598 int ssb_sdio_init(struct ssb_bus *bus)
599 {
600 	if (bus->bustype != SSB_BUSTYPE_SDIO)
601 		return 0;
602 
603 	bus->sdio_sbaddr = ~0;
604 
605 	return 0;
606 }
607