xref: /freebsd/sys/dev/ichsmb/ichsmb.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
1 /*-
2  * ichsmb.c
3  *
4  * Author: Archie Cobbs <archie@freebsd.org>
5  * Copyright (c) 2000 Whistle Communications, Inc.
6  * All rights reserved.
7  *
8  * Subject to the following obligations and disclaimer of warranty, use and
9  * redistribution of this software, in source or object code forms, with or
10  * without modifications are expressly permitted by Whistle Communications;
11  * provided, however, that:
12  * 1. Any and all reproductions of the source or object code must include the
13  *    copyright notice above and the following disclaimer of warranties; and
14  * 2. No rights are granted, in any manner or form, to use Whistle
15  *    Communications, Inc. trademarks, including the mark "WHISTLE
16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17  *    such appears in the above copyright notice or in the software.
18  *
19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 /*
42  * Support for the SMBus controller logical device which is part of the
43  * Intel 81801AA (ICH) and 81801AB (ICH0) I/O controller hub chips.
44  *
45  * This driver assumes that the generic SMBus code will ensure that
46  * at most one process at a time calls into the SMBus methods below.
47  */
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/errno.h>
53 #include <sys/lock.h>
54 #include <sys/module.h>
55 #include <sys/mutex.h>
56 #include <sys/syslog.h>
57 #include <sys/bus.h>
58 
59 #include <machine/bus.h>
60 #include <sys/rman.h>
61 #include <machine/resource.h>
62 
63 #include <dev/smbus/smbconf.h>
64 
65 #include <dev/ichsmb/ichsmb_var.h>
66 #include <dev/ichsmb/ichsmb_reg.h>
67 
68 /*
69  * Enable debugging by defining ICHSMB_DEBUG to a non-zero value.
70  */
71 #define ICHSMB_DEBUG	0
72 #if ICHSMB_DEBUG != 0 && defined(__CC_SUPPORTS___FUNC__)
73 #define DBG(fmt, args...)	\
74 	do { printf("%s: " fmt, __func__ , ## args); } while (0)
75 #else
76 #define DBG(fmt, args...)	do { } while (0)
77 #endif
78 
79 /*
80  * Our child device driver name
81  */
82 #define DRIVER_SMBUS	"smbus"
83 
84 /*
85  * Internal functions
86  */
87 static int ichsmb_wait(sc_p sc);
88 
89 /********************************************************************
90 		BUS-INDEPENDENT BUS METHODS
91 ********************************************************************/
92 
93 /*
94  * Handle probe-time duties that are independent of the bus
95  * our device lives on.
96  */
97 int
98 ichsmb_probe(device_t dev)
99 {
100 	return (BUS_PROBE_DEFAULT);
101 }
102 
103 /*
104  * Handle attach-time duties that are independent of the bus
105  * our device lives on.
106  */
107 int
108 ichsmb_attach(device_t dev)
109 {
110 	const sc_p sc = device_get_softc(dev);
111 	int error;
112 
113 	/* Create mutex */
114 	mtx_init(&sc->mutex, device_get_nameunit(dev), "ichsmb", MTX_DEF);
115 
116 	/* Add child: an instance of the "smbus" device */
117 	if ((sc->smb = device_add_child(dev, DRIVER_SMBUS, -1)) == NULL) {
118 		device_printf(dev, "no \"%s\" child found\n", DRIVER_SMBUS);
119 		error = ENXIO;
120 		goto fail;
121 	}
122 
123 	/* Clear interrupt conditions */
124 	bus_write_1(sc->io_res, ICH_HST_STA, 0xff);
125 
126 	/* Set up interrupt handler */
127 	error = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
128 	    NULL, ichsmb_device_intr, sc, &sc->irq_handle);
129 	if (error != 0) {
130 		device_printf(dev, "can't setup irq\n");
131 		goto fail;
132 	}
133 
134 	/* Attach "smbus" child */
135 	if ((error = bus_generic_attach(dev)) != 0) {
136 		device_printf(dev, "failed to attach child: %d\n", error);
137 		goto fail;
138 	}
139 
140 	return (0);
141 
142 fail:
143 	mtx_destroy(&sc->mutex);
144 	return (error);
145 }
146 
147 /********************************************************************
148 			SMBUS METHODS
149 ********************************************************************/
150 
151 int
152 ichsmb_callback(device_t dev, int index, void *data)
153 {
154 	int smb_error = 0;
155 
156 	DBG("index=%d how=%d\n", index, data ? *(int *)data : -1);
157 	switch (index) {
158 	case SMB_REQUEST_BUS:
159 		break;
160 	case SMB_RELEASE_BUS:
161 		break;
162 	default:
163 		smb_error = SMB_EABORT;	/* XXX */
164 		break;
165 	}
166 	DBG("smb_error=%d\n", smb_error);
167 	return (smb_error);
168 }
169 
170 int
171 ichsmb_quick(device_t dev, u_char slave, int how)
172 {
173 	const sc_p sc = device_get_softc(dev);
174 	int smb_error;
175 
176 	DBG("slave=0x%02x how=%d\n", slave, how);
177 	KASSERT(sc->ich_cmd == -1,
178 	    ("%s: ich_cmd=%d\n", __func__ , sc->ich_cmd));
179 	switch (how) {
180 	case SMB_QREAD:
181 	case SMB_QWRITE:
182 		mtx_lock(&sc->mutex);
183 		sc->ich_cmd = ICH_HST_CNT_SMB_CMD_QUICK;
184 		bus_write_1(sc->io_res, ICH_XMIT_SLVA,
185 		    slave | (how == SMB_QREAD ?
186 	    		ICH_XMIT_SLVA_READ : ICH_XMIT_SLVA_WRITE));
187 		bus_write_1(sc->io_res, ICH_HST_CNT,
188 		    ICH_HST_CNT_START | ICH_HST_CNT_INTREN | sc->ich_cmd);
189 		smb_error = ichsmb_wait(sc);
190 		mtx_unlock(&sc->mutex);
191 		break;
192 	default:
193 		smb_error = SMB_ENOTSUPP;
194 	}
195 	DBG("smb_error=%d\n", smb_error);
196 	return (smb_error);
197 }
198 
199 int
200 ichsmb_sendb(device_t dev, u_char slave, char byte)
201 {
202 	const sc_p sc = device_get_softc(dev);
203 	int smb_error;
204 
205 	DBG("slave=0x%02x byte=0x%02x\n", slave, (u_char)byte);
206 	KASSERT(sc->ich_cmd == -1,
207 	    ("%s: ich_cmd=%d\n", __func__ , sc->ich_cmd));
208 	mtx_lock(&sc->mutex);
209 	sc->ich_cmd = ICH_HST_CNT_SMB_CMD_BYTE;
210 	bus_write_1(sc->io_res, ICH_XMIT_SLVA,
211 	    slave | ICH_XMIT_SLVA_WRITE);
212 	bus_write_1(sc->io_res, ICH_HST_CMD, byte);
213 	bus_write_1(sc->io_res, ICH_HST_CNT,
214 	    ICH_HST_CNT_START | ICH_HST_CNT_INTREN | sc->ich_cmd);
215 	smb_error = ichsmb_wait(sc);
216 	mtx_unlock(&sc->mutex);
217 	DBG("smb_error=%d\n", smb_error);
218 	return (smb_error);
219 }
220 
221 int
222 ichsmb_recvb(device_t dev, u_char slave, char *byte)
223 {
224 	const sc_p sc = device_get_softc(dev);
225 	int smb_error;
226 
227 	DBG("slave=0x%02x\n", slave);
228 	KASSERT(sc->ich_cmd == -1,
229 	    ("%s: ich_cmd=%d\n", __func__ , sc->ich_cmd));
230 	mtx_lock(&sc->mutex);
231 	sc->ich_cmd = ICH_HST_CNT_SMB_CMD_BYTE;
232 	bus_write_1(sc->io_res, ICH_XMIT_SLVA,
233 	    slave | ICH_XMIT_SLVA_READ);
234 	bus_write_1(sc->io_res, ICH_HST_CNT,
235 	    ICH_HST_CNT_START | ICH_HST_CNT_INTREN | sc->ich_cmd);
236 	if ((smb_error = ichsmb_wait(sc)) == SMB_ENOERR)
237 		*byte = bus_read_1(sc->io_res, ICH_D0);
238 	mtx_unlock(&sc->mutex);
239 	DBG("smb_error=%d byte=0x%02x\n", smb_error, (u_char)*byte);
240 	return (smb_error);
241 }
242 
243 int
244 ichsmb_writeb(device_t dev, u_char slave, char cmd, char byte)
245 {
246 	const sc_p sc = device_get_softc(dev);
247 	int smb_error;
248 
249 	DBG("slave=0x%02x cmd=0x%02x byte=0x%02x\n",
250 	    slave, (u_char)cmd, (u_char)byte);
251 	KASSERT(sc->ich_cmd == -1,
252 	    ("%s: ich_cmd=%d\n", __func__ , sc->ich_cmd));
253 	mtx_lock(&sc->mutex);
254 	sc->ich_cmd = ICH_HST_CNT_SMB_CMD_BYTE_DATA;
255 	bus_write_1(sc->io_res, ICH_XMIT_SLVA,
256 	    slave | ICH_XMIT_SLVA_WRITE);
257 	bus_write_1(sc->io_res, ICH_HST_CMD, cmd);
258 	bus_write_1(sc->io_res, ICH_D0, byte);
259 	bus_write_1(sc->io_res, ICH_HST_CNT,
260 	    ICH_HST_CNT_START | ICH_HST_CNT_INTREN | sc->ich_cmd);
261 	smb_error = ichsmb_wait(sc);
262 	mtx_unlock(&sc->mutex);
263 	DBG("smb_error=%d\n", smb_error);
264 	return (smb_error);
265 }
266 
267 int
268 ichsmb_writew(device_t dev, u_char slave, char cmd, short word)
269 {
270 	const sc_p sc = device_get_softc(dev);
271 	int smb_error;
272 
273 	DBG("slave=0x%02x cmd=0x%02x word=0x%04x\n",
274 	    slave, (u_char)cmd, (u_int16_t)word);
275 	KASSERT(sc->ich_cmd == -1,
276 	    ("%s: ich_cmd=%d\n", __func__ , sc->ich_cmd));
277 	mtx_lock(&sc->mutex);
278 	sc->ich_cmd = ICH_HST_CNT_SMB_CMD_WORD_DATA;
279 	bus_write_1(sc->io_res, ICH_XMIT_SLVA,
280 	    slave | ICH_XMIT_SLVA_WRITE);
281 	bus_write_1(sc->io_res, ICH_HST_CMD, cmd);
282 	bus_write_1(sc->io_res, ICH_D0, word & 0xff);
283 	bus_write_1(sc->io_res, ICH_D1, word >> 8);
284 	bus_write_1(sc->io_res, ICH_HST_CNT,
285 	    ICH_HST_CNT_START | ICH_HST_CNT_INTREN | sc->ich_cmd);
286 	smb_error = ichsmb_wait(sc);
287 	mtx_unlock(&sc->mutex);
288 	DBG("smb_error=%d\n", smb_error);
289 	return (smb_error);
290 }
291 
292 int
293 ichsmb_readb(device_t dev, u_char slave, char cmd, char *byte)
294 {
295 	const sc_p sc = device_get_softc(dev);
296 	int smb_error;
297 
298 	DBG("slave=0x%02x cmd=0x%02x\n", slave, (u_char)cmd);
299 	KASSERT(sc->ich_cmd == -1,
300 	    ("%s: ich_cmd=%d\n", __func__ , sc->ich_cmd));
301 	mtx_lock(&sc->mutex);
302 	sc->ich_cmd = ICH_HST_CNT_SMB_CMD_BYTE_DATA;
303 	bus_write_1(sc->io_res, ICH_XMIT_SLVA,
304 	    slave | ICH_XMIT_SLVA_READ);
305 	bus_write_1(sc->io_res, ICH_HST_CMD, cmd);
306 	bus_write_1(sc->io_res, ICH_HST_CNT,
307 	    ICH_HST_CNT_START | ICH_HST_CNT_INTREN | sc->ich_cmd);
308 	if ((smb_error = ichsmb_wait(sc)) == SMB_ENOERR)
309 		*byte = bus_read_1(sc->io_res, ICH_D0);
310 	mtx_unlock(&sc->mutex);
311 	DBG("smb_error=%d byte=0x%02x\n", smb_error, (u_char)*byte);
312 	return (smb_error);
313 }
314 
315 int
316 ichsmb_readw(device_t dev, u_char slave, char cmd, short *word)
317 {
318 	const sc_p sc = device_get_softc(dev);
319 	int smb_error;
320 
321 	DBG("slave=0x%02x cmd=0x%02x\n", slave, (u_char)cmd);
322 	KASSERT(sc->ich_cmd == -1,
323 	    ("%s: ich_cmd=%d\n", __func__ , sc->ich_cmd));
324 	mtx_lock(&sc->mutex);
325 	sc->ich_cmd = ICH_HST_CNT_SMB_CMD_WORD_DATA;
326 	bus_write_1(sc->io_res, ICH_XMIT_SLVA,
327 	    slave | ICH_XMIT_SLVA_READ);
328 	bus_write_1(sc->io_res, ICH_HST_CMD, cmd);
329 	bus_write_1(sc->io_res, ICH_HST_CNT,
330 	    ICH_HST_CNT_START | ICH_HST_CNT_INTREN | sc->ich_cmd);
331 	if ((smb_error = ichsmb_wait(sc)) == SMB_ENOERR) {
332 		*word = (bus_read_1(sc->io_res,
333 			ICH_D0) & 0xff)
334 		  | (bus_read_1(sc->io_res,
335 			ICH_D1) << 8);
336 	}
337 	mtx_unlock(&sc->mutex);
338 	DBG("smb_error=%d word=0x%04x\n", smb_error, (u_int16_t)*word);
339 	return (smb_error);
340 }
341 
342 int
343 ichsmb_pcall(device_t dev, u_char slave, char cmd, short sdata, short *rdata)
344 {
345 	const sc_p sc = device_get_softc(dev);
346 	int smb_error;
347 
348 	DBG("slave=0x%02x cmd=0x%02x sdata=0x%04x\n",
349 	    slave, (u_char)cmd, (u_int16_t)sdata);
350 	KASSERT(sc->ich_cmd == -1,
351 	    ("%s: ich_cmd=%d\n", __func__ , sc->ich_cmd));
352 	mtx_lock(&sc->mutex);
353 	sc->ich_cmd = ICH_HST_CNT_SMB_CMD_PROC_CALL;
354 	bus_write_1(sc->io_res, ICH_XMIT_SLVA,
355 	    slave | ICH_XMIT_SLVA_WRITE);
356 	bus_write_1(sc->io_res, ICH_HST_CMD, cmd);
357 	bus_write_1(sc->io_res, ICH_D0, sdata & 0xff);
358 	bus_write_1(sc->io_res, ICH_D1, sdata >> 8);
359 	bus_write_1(sc->io_res, ICH_HST_CNT,
360 	    ICH_HST_CNT_START | ICH_HST_CNT_INTREN | sc->ich_cmd);
361 	if ((smb_error = ichsmb_wait(sc)) == SMB_ENOERR) {
362 		*rdata = (bus_read_1(sc->io_res,
363 			ICH_D0) & 0xff)
364 		  | (bus_read_1(sc->io_res,
365 			ICH_D1) << 8);
366 	}
367 	mtx_unlock(&sc->mutex);
368 	DBG("smb_error=%d rdata=0x%04x\n", smb_error, (u_int16_t)*rdata);
369 	return (smb_error);
370 }
371 
372 int
373 ichsmb_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf)
374 {
375 	const sc_p sc = device_get_softc(dev);
376 	int smb_error;
377 
378 	DBG("slave=0x%02x cmd=0x%02x count=%d\n", slave, (u_char)cmd, count);
379 #if ICHSMB_DEBUG
380 #define DISP(ch)	(((ch) < 0x20 || (ch) >= 0x7e) ? '.' : (ch))
381 	{
382 	    u_char *p;
383 
384 	    for (p = (u_char *)buf; p - (u_char *)buf < 32; p += 8) {
385 		DBG("%02x: %02x %02x %02x %02x %02x %02x %02x %02x"
386 		    "  %c%c%c%c%c%c%c%c", (p - (u_char *)buf),
387 		    p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
388 		    DISP(p[0]), DISP(p[1]), DISP(p[2]), DISP(p[3]),
389 		    DISP(p[4]), DISP(p[5]), DISP(p[6]), DISP(p[7]));
390 	    }
391 	}
392 #undef DISP
393 #endif
394 	KASSERT(sc->ich_cmd == -1,
395 	    ("%s: ich_cmd=%d\n", __func__ , sc->ich_cmd));
396 	if (count < 1 || count > 32)
397 		return (SMB_EINVAL);
398 	bcopy(buf, sc->block_data, count);
399 	sc->block_count = count;
400 	sc->block_index = 1;
401 	sc->block_write = 1;
402 
403 	mtx_lock(&sc->mutex);
404 	sc->ich_cmd = ICH_HST_CNT_SMB_CMD_BLOCK;
405 	bus_write_1(sc->io_res, ICH_XMIT_SLVA,
406 	    slave | ICH_XMIT_SLVA_WRITE);
407 	bus_write_1(sc->io_res, ICH_HST_CMD, cmd);
408 	bus_write_1(sc->io_res, ICH_D0, count);
409 	bus_write_1(sc->io_res, ICH_BLOCK_DB, buf[0]);
410 	bus_write_1(sc->io_res, ICH_HST_CNT,
411 	    ICH_HST_CNT_START | ICH_HST_CNT_INTREN | sc->ich_cmd);
412 	smb_error = ichsmb_wait(sc);
413 	mtx_unlock(&sc->mutex);
414 	DBG("smb_error=%d\n", smb_error);
415 	return (smb_error);
416 }
417 
418 int
419 ichsmb_bread(device_t dev, u_char slave, char cmd, u_char *count, char *buf)
420 {
421 	const sc_p sc = device_get_softc(dev);
422 	int smb_error;
423 
424 	DBG("slave=0x%02x cmd=0x%02x count=%d\n", slave, (u_char)cmd, count);
425 	KASSERT(sc->ich_cmd == -1,
426 	    ("%s: ich_cmd=%d\n", __func__ , sc->ich_cmd));
427 	if (*count < 1 || *count > 32)
428 		return (SMB_EINVAL);
429 	bzero(sc->block_data, sizeof(sc->block_data));
430 	sc->block_count = 0;
431 	sc->block_index = 0;
432 	sc->block_write = 0;
433 
434 	mtx_lock(&sc->mutex);
435 	sc->ich_cmd = ICH_HST_CNT_SMB_CMD_BLOCK;
436 	bus_write_1(sc->io_res, ICH_XMIT_SLVA,
437 	    slave | ICH_XMIT_SLVA_READ);
438 	bus_write_1(sc->io_res, ICH_HST_CMD, cmd);
439 	bus_write_1(sc->io_res, ICH_D0, *count); /* XXX? */
440 	bus_write_1(sc->io_res, ICH_HST_CNT,
441 	    ICH_HST_CNT_START | ICH_HST_CNT_INTREN | sc->ich_cmd);
442 	if ((smb_error = ichsmb_wait(sc)) == SMB_ENOERR) {
443 		bcopy(sc->block_data, buf, min(sc->block_count, *count));
444 		*count = sc->block_count;
445 	}
446 	mtx_unlock(&sc->mutex);
447 	DBG("smb_error=%d\n", smb_error);
448 #if ICHSMB_DEBUG
449 #define DISP(ch)	(((ch) < 0x20 || (ch) >= 0x7e) ? '.' : (ch))
450 	{
451 	    u_char *p;
452 
453 	    for (p = (u_char *)buf; p - (u_char *)buf < 32; p += 8) {
454 		DBG("%02x: %02x %02x %02x %02x %02x %02x %02x %02x"
455 		    "  %c%c%c%c%c%c%c%c", (p - (u_char *)buf),
456 		    p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
457 		    DISP(p[0]), DISP(p[1]), DISP(p[2]), DISP(p[3]),
458 		    DISP(p[4]), DISP(p[5]), DISP(p[6]), DISP(p[7]));
459 	    }
460 	}
461 #undef DISP
462 #endif
463 	return (smb_error);
464 }
465 
466 /********************************************************************
467 			OTHER FUNCTIONS
468 ********************************************************************/
469 
470 /*
471  * This table describes what interrupts we should ever expect to
472  * see after each ICH command, not including the SMBALERT interrupt.
473  */
474 static const u_int8_t ichsmb_state_irqs[] = {
475 	/* quick */
476 	(ICH_HST_STA_BUS_ERR | ICH_HST_STA_DEV_ERR | ICH_HST_STA_INTR),
477 	/* byte */
478 	(ICH_HST_STA_BUS_ERR | ICH_HST_STA_DEV_ERR | ICH_HST_STA_INTR),
479 	/* byte data */
480 	(ICH_HST_STA_BUS_ERR | ICH_HST_STA_DEV_ERR | ICH_HST_STA_INTR),
481 	/* word data */
482 	(ICH_HST_STA_BUS_ERR | ICH_HST_STA_DEV_ERR | ICH_HST_STA_INTR),
483 	/* process call */
484 	(ICH_HST_STA_BUS_ERR | ICH_HST_STA_DEV_ERR | ICH_HST_STA_INTR),
485 	/* block */
486 	(ICH_HST_STA_BUS_ERR | ICH_HST_STA_DEV_ERR | ICH_HST_STA_INTR
487 	    | ICH_HST_STA_BYTE_DONE_STS),
488 	/* i2c read (not used) */
489 	(ICH_HST_STA_BUS_ERR | ICH_HST_STA_DEV_ERR | ICH_HST_STA_INTR
490 	    | ICH_HST_STA_BYTE_DONE_STS)
491 };
492 
493 /*
494  * Interrupt handler. This handler is bus-independent. Note that our
495  * interrupt may be shared, so we must handle "false" interrupts.
496  */
497 void
498 ichsmb_device_intr(void *cookie)
499 {
500 	const sc_p sc = cookie;
501 	const device_t dev = sc->dev;
502 	const int maxloops = 16;
503 	u_int8_t status;
504 	u_int8_t ok_bits;
505 	int cmd_index;
506         int count;
507 
508 	mtx_lock(&sc->mutex);
509 	for (count = 0; count < maxloops; count++) {
510 
511 		/* Get and reset status bits */
512 		status = bus_read_1(sc->io_res, ICH_HST_STA);
513 #if ICHSMB_DEBUG
514 		if ((status & ~(ICH_HST_STA_INUSE_STS | ICH_HST_STA_HOST_BUSY))
515 		    || count > 0) {
516 			DBG("%d stat=0x%02x\n", count, status);
517 		}
518 #endif
519 		status &= ~(ICH_HST_STA_INUSE_STS | ICH_HST_STA_HOST_BUSY);
520 		if (status == 0)
521 			break;
522 
523 		/* Check for unexpected interrupt */
524 		ok_bits = ICH_HST_STA_SMBALERT_STS;
525 		cmd_index = sc->ich_cmd >> 2;
526 		if (sc->ich_cmd != -1) {
527 			KASSERT(cmd_index < sizeof(ichsmb_state_irqs),
528 			    ("%s: ich_cmd=%d", device_get_nameunit(dev),
529 			    sc->ich_cmd));
530 			ok_bits |= ichsmb_state_irqs[cmd_index];
531 		}
532 		if ((status & ~ok_bits) != 0) {
533 			device_printf(dev, "irq 0x%02x during %d\n", status,
534 			    cmd_index);
535 			bus_write_1(sc->io_res,
536 			    ICH_HST_STA, (status & ~ok_bits));
537 			continue;
538 		}
539 
540 		/* Handle SMBALERT interrupt */
541 		if (status & ICH_HST_STA_SMBALERT_STS) {
542 			static int smbalert_count = 16;
543 			if (smbalert_count > 0) {
544 				device_printf(dev, "SMBALERT# rec'd\n");
545 				if (--smbalert_count == 0) {
546 					device_printf(dev,
547 					    "not logging anymore\n");
548 				}
549 			}
550 		}
551 
552 		/* Check for bus error */
553 		if (status & ICH_HST_STA_BUS_ERR) {
554 			sc->smb_error = SMB_ECOLLI;	/* XXX SMB_EBUSERR? */
555 			goto finished;
556 		}
557 
558 		/* Check for device error */
559 		if (status & ICH_HST_STA_DEV_ERR) {
560 			sc->smb_error = SMB_ENOACK;	/* or SMB_ETIMEOUT? */
561 			goto finished;
562 		}
563 
564 		/* Check for byte completion in block transfer */
565 		if (status & ICH_HST_STA_BYTE_DONE_STS) {
566 			if (sc->block_write) {
567 				if (sc->block_index < sc->block_count) {
568 
569 					/* Write next byte */
570 					bus_write_1(sc->io_res,
571 					    ICH_BLOCK_DB,
572 					    sc->block_data[sc->block_index++]);
573 				}
574 			} else {
575 
576 				/* First interrupt, get the count also */
577 				if (sc->block_index == 0) {
578 					sc->block_count = bus_read_1(
579 					    sc->io_res, ICH_D0);
580 				}
581 
582 				/* Get next byte, if any */
583 				if (sc->block_index < sc->block_count) {
584 
585 					/* Read next byte */
586 					sc->block_data[sc->block_index++] =
587 					    bus_read_1(sc->io_res,
588 					      ICH_BLOCK_DB);
589 
590 					/* Set "LAST_BYTE" bit before reading
591 					   the last byte of block data */
592 					if (sc->block_index
593 					    >= sc->block_count - 1) {
594 						bus_write_1(sc->io_res,
595 						    ICH_HST_CNT,
596 						    ICH_HST_CNT_LAST_BYTE
597 							| ICH_HST_CNT_INTREN
598 							| sc->ich_cmd);
599 					}
600 				}
601 			}
602 		}
603 
604 		/* Check command completion */
605 		if (status & ICH_HST_STA_INTR) {
606 			sc->smb_error = SMB_ENOERR;
607 finished:
608 			sc->ich_cmd = -1;
609 			bus_write_1(sc->io_res,
610 			    ICH_HST_STA, status);
611 			wakeup(sc);
612 			break;
613 		}
614 
615 		/* Clear status bits and try again */
616 		bus_write_1(sc->io_res, ICH_HST_STA, status);
617 	}
618 	mtx_unlock(&sc->mutex);
619 
620 	/* Too many loops? */
621 	if (count == maxloops) {
622 		device_printf(dev, "interrupt loop, status=0x%02x\n",
623 		    bus_read_1(sc->io_res, ICH_HST_STA));
624 	}
625 }
626 
627 /*
628  * Wait for command completion. Assumes mutex is held.
629  * Returns an SMB_* error code.
630  */
631 static int
632 ichsmb_wait(sc_p sc)
633 {
634 	const device_t dev = sc->dev;
635 	int error, smb_error;
636 
637 	KASSERT(sc->ich_cmd != -1,
638 	    ("%s: ich_cmd=%d\n", __func__ , sc->ich_cmd));
639 	mtx_assert(&sc->mutex, MA_OWNED);
640 	error = msleep(sc, &sc->mutex, PZERO, "ichsmb", hz / 4);
641 	DBG("msleep -> %d\n", error);
642 	switch (error) {
643 	case 0:
644 		smb_error = sc->smb_error;
645 		break;
646 	case EWOULDBLOCK:
647 		device_printf(dev, "device timeout, status=0x%02x\n",
648 		    bus_read_1(sc->io_res, ICH_HST_STA));
649 		sc->ich_cmd = -1;
650 		smb_error = SMB_ETIMEOUT;
651 		break;
652 	default:
653 		smb_error = SMB_EABORT;
654 		break;
655 	}
656 	return (smb_error);
657 }
658 
659 /*
660  * Release resources associated with device.
661  */
662 void
663 ichsmb_release_resources(sc_p sc)
664 {
665 	const device_t dev = sc->dev;
666 
667 	if (sc->irq_handle != NULL) {
668 		bus_teardown_intr(dev, sc->irq_res, sc->irq_handle);
669 		sc->irq_handle = NULL;
670 	}
671 	if (sc->irq_res != NULL) {
672 		bus_release_resource(dev,
673 		    SYS_RES_IRQ, sc->irq_rid, sc->irq_res);
674 		sc->irq_res = NULL;
675 	}
676 	if (sc->io_res != NULL) {
677 		bus_release_resource(dev,
678 		    SYS_RES_IOPORT, sc->io_rid, sc->io_res);
679 		sc->io_res = NULL;
680 	}
681 }
682 
683 int
684 ichsmb_detach(device_t dev)
685 {
686 	const sc_p sc = device_get_softc(dev);
687 	int error;
688 
689 	error = bus_generic_detach(dev);
690 	if (error)
691 		return (error);
692 	device_delete_child(dev, sc->smb);
693 	ichsmb_release_resources(sc);
694 	mtx_destroy(&sc->mutex);
695 
696 	return 0;
697 }
698 
699 DRIVER_MODULE(smbus, ichsmb, smbus_driver, smbus_devclass, 0, 0);
700