xref: /openbmc/linux/drivers/char/ipmi/ipmi_smic_sm.c (revision 643d1f7f)
1 /*
2  * ipmi_smic_sm.c
3  *
4  * The state-machine driver for an IPMI SMIC driver
5  *
6  * It started as a copy of Corey Minyard's driver for the KSC interface
7  * and the kernel patch "mmcdev-patch-245" by HP
8  *
9  * modified by:	Hannes Schulz <schulz@schwaar.com>
10  *		ipmi@schwaar.com
11  *
12  *
13  * Corey Minyard's driver for the KSC interface has the following
14  * copyright notice:
15  *   Copyright 2002 MontaVista Software Inc.
16  *
17  * the kernel patch "mmcdev-patch-245" by HP has the following
18  * copyright notice:
19  * (c) Copyright 2001 Grant Grundler (c) Copyright
20  * 2001 Hewlett-Packard Company
21  *
22  *
23  *  This program is free software; you can redistribute it and/or modify it
24  *  under the terms of the GNU General Public License as published by the
25  *  Free Software Foundation; either version 2 of the License, or (at your
26  *  option) any later version.
27  *
28  *
29  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
30  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
31  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32  *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
33  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
34  *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
35  *  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
36  *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
37  *  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
38  *  USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39  *
40  *  You should have received a copy of the GNU General Public License along
41  *  with this program; if not, write to the Free Software Foundation, Inc.,
42  *  675 Mass Ave, Cambridge, MA 02139, USA.  */
43 
44 #include <linux/kernel.h> /* For printk. */
45 #include <linux/string.h>
46 #include <linux/module.h>
47 #include <linux/moduleparam.h>
48 #include <linux/ipmi_msgdefs.h>		/* for completion codes */
49 #include "ipmi_si_sm.h"
50 
51 /* smic_debug is a bit-field
52  *	SMIC_DEBUG_ENABLE -	turned on for now
53  *	SMIC_DEBUG_MSG -	commands and their responses
54  *	SMIC_DEBUG_STATES -	state machine
55 */
56 #define SMIC_DEBUG_STATES	4
57 #define SMIC_DEBUG_MSG		2
58 #define	SMIC_DEBUG_ENABLE	1
59 
60 static int smic_debug = 1;
61 module_param(smic_debug, int, 0644);
62 MODULE_PARM_DESC(smic_debug, "debug bitmask, 1=enable, 2=messages, 4=states");
63 
64 enum smic_states {
65 	SMIC_IDLE,
66 	SMIC_START_OP,
67 	SMIC_OP_OK,
68 	SMIC_WRITE_START,
69 	SMIC_WRITE_NEXT,
70 	SMIC_WRITE_END,
71 	SMIC_WRITE2READ,
72 	SMIC_READ_START,
73 	SMIC_READ_NEXT,
74 	SMIC_READ_END,
75 	SMIC_HOSED
76 };
77 
78 #define MAX_SMIC_READ_SIZE 80
79 #define MAX_SMIC_WRITE_SIZE 80
80 #define SMIC_MAX_ERROR_RETRIES 3
81 
82 /* Timeouts in microseconds. */
83 #define SMIC_RETRY_TIMEOUT 2000000
84 
85 /* SMIC Flags Register Bits */
86 #define SMIC_RX_DATA_READY	0x80
87 #define SMIC_TX_DATA_READY	0x40
88 /*
89  * SMIC_SMI and SMIC_EVM_DATA_AVAIL are only used by
90  * a few systems, and then only by Systems Management
91  * Interrupts, not by the OS.  Always ignore these bits.
92  *
93  */
94 #define SMIC_SMI		0x10
95 #define SMIC_EVM_DATA_AVAIL	0x08
96 #define SMIC_SMS_DATA_AVAIL	0x04
97 #define SMIC_FLAG_BSY		0x01
98 
99 /* SMIC Error Codes */
100 #define	EC_NO_ERROR		0x00
101 #define	EC_ABORTED		0x01
102 #define	EC_ILLEGAL_CONTROL	0x02
103 #define	EC_NO_RESPONSE		0x03
104 #define	EC_ILLEGAL_COMMAND	0x04
105 #define	EC_BUFFER_FULL		0x05
106 
107 struct si_sm_data
108 {
109 	enum smic_states state;
110 	struct si_sm_io *io;
111         unsigned char	 write_data[MAX_SMIC_WRITE_SIZE];
112         int		 write_pos;
113         int		 write_count;
114         int		 orig_write_count;
115         unsigned char	 read_data[MAX_SMIC_READ_SIZE];
116         int		 read_pos;
117         int		 truncated;
118         unsigned int	 error_retries;
119         long		 smic_timeout;
120 };
121 
122 static unsigned int init_smic_data (struct si_sm_data *smic,
123 				    struct si_sm_io *io)
124 {
125 	smic->state = SMIC_IDLE;
126 	smic->io = io;
127 	smic->write_pos = 0;
128 	smic->write_count = 0;
129 	smic->orig_write_count = 0;
130 	smic->read_pos = 0;
131 	smic->error_retries = 0;
132 	smic->truncated = 0;
133 	smic->smic_timeout = SMIC_RETRY_TIMEOUT;
134 
135 	/* We use 3 bytes of I/O. */
136 	return 3;
137 }
138 
139 static int start_smic_transaction(struct si_sm_data *smic,
140 				  unsigned char *data, unsigned int size)
141 {
142 	unsigned int i;
143 
144 	if (size < 2)
145 		return IPMI_REQ_LEN_INVALID_ERR;
146 	if (size > MAX_SMIC_WRITE_SIZE)
147 		return IPMI_REQ_LEN_EXCEEDED_ERR;
148 
149 	if ((smic->state != SMIC_IDLE) && (smic->state != SMIC_HOSED))
150 		return IPMI_NOT_IN_MY_STATE_ERR;
151 
152 	if (smic_debug & SMIC_DEBUG_MSG) {
153 		printk(KERN_INFO "start_smic_transaction -");
154 		for (i = 0; i < size; i ++) {
155 			printk (" %02x", (unsigned char) (data [i]));
156 		}
157 		printk ("\n");
158 	}
159 	smic->error_retries = 0;
160 	memcpy(smic->write_data, data, size);
161 	smic->write_count = size;
162 	smic->orig_write_count = size;
163 	smic->write_pos = 0;
164 	smic->read_pos = 0;
165 	smic->state = SMIC_START_OP;
166 	smic->smic_timeout = SMIC_RETRY_TIMEOUT;
167 	return 0;
168 }
169 
170 static int smic_get_result(struct si_sm_data *smic,
171 			   unsigned char *data, unsigned int length)
172 {
173 	int i;
174 
175 	if (smic_debug & SMIC_DEBUG_MSG) {
176 		printk (KERN_INFO "smic_get result -");
177 		for (i = 0; i < smic->read_pos; i ++) {
178 			printk (" %02x", (smic->read_data [i]));
179 		}
180 		printk ("\n");
181 	}
182 	if (length < smic->read_pos) {
183 		smic->read_pos = length;
184 		smic->truncated = 1;
185 	}
186 	memcpy(data, smic->read_data, smic->read_pos);
187 
188 	if ((length >= 3) && (smic->read_pos < 3)) {
189 		data[2] = IPMI_ERR_UNSPECIFIED;
190 		smic->read_pos = 3;
191 	}
192 	if (smic->truncated) {
193 		data[2] = IPMI_ERR_MSG_TRUNCATED;
194 		smic->truncated = 0;
195 	}
196 	return smic->read_pos;
197 }
198 
199 static inline unsigned char read_smic_flags(struct si_sm_data *smic)
200 {
201 	return smic->io->inputb(smic->io, 2);
202 }
203 
204 static inline unsigned char read_smic_status(struct si_sm_data *smic)
205 {
206 	return smic->io->inputb(smic->io, 1);
207 }
208 
209 static inline unsigned char read_smic_data(struct si_sm_data *smic)
210 {
211 	return smic->io->inputb(smic->io, 0);
212 }
213 
214 static inline void write_smic_flags(struct si_sm_data *smic,
215 				    unsigned char   flags)
216 {
217 	smic->io->outputb(smic->io, 2, flags);
218 }
219 
220 static inline void write_smic_control(struct si_sm_data *smic,
221 				      unsigned char   control)
222 {
223 	smic->io->outputb(smic->io, 1, control);
224 }
225 
226 static inline void write_si_sm_data (struct si_sm_data *smic,
227 				   unsigned char   data)
228 {
229 	smic->io->outputb(smic->io, 0, data);
230 }
231 
232 static inline void start_error_recovery(struct si_sm_data *smic, char *reason)
233 {
234 	(smic->error_retries)++;
235 	if (smic->error_retries > SMIC_MAX_ERROR_RETRIES) {
236 		if (smic_debug & SMIC_DEBUG_ENABLE) {
237 			printk(KERN_WARNING
238 			       "ipmi_smic_drv: smic hosed: %s\n", reason);
239 		}
240 		smic->state = SMIC_HOSED;
241 	} else {
242 		smic->write_count = smic->orig_write_count;
243 		smic->write_pos = 0;
244 		smic->read_pos = 0;
245 		smic->state = SMIC_START_OP;
246 		smic->smic_timeout = SMIC_RETRY_TIMEOUT;
247 	}
248 }
249 
250 static inline void write_next_byte(struct si_sm_data *smic)
251 {
252 	write_si_sm_data(smic, smic->write_data[smic->write_pos]);
253 	(smic->write_pos)++;
254 	(smic->write_count)--;
255 }
256 
257 static inline void read_next_byte (struct si_sm_data *smic)
258 {
259 	if (smic->read_pos >= MAX_SMIC_READ_SIZE) {
260 		read_smic_data (smic);
261 		smic->truncated = 1;
262 	} else {
263 		smic->read_data[smic->read_pos] = read_smic_data(smic);
264 		(smic->read_pos)++;
265 	}
266 }
267 
268 /*  SMIC Control/Status Code Components */
269 #define	SMIC_GET_STATUS		0x00	/* Control form's name */
270 #define	SMIC_READY		0x00	/* Status  form's name */
271 #define	SMIC_WR_START		0x01	/* Unified Control/Status names... */
272 #define	SMIC_WR_NEXT		0x02
273 #define	SMIC_WR_END		0x03
274 #define	SMIC_RD_START		0x04
275 #define	SMIC_RD_NEXT		0x05
276 #define	SMIC_RD_END		0x06
277 #define	SMIC_CODE_MASK		0x0f
278 
279 #define	SMIC_CONTROL		0x00
280 #define	SMIC_STATUS		0x80
281 #define	SMIC_CS_MASK		0x80
282 
283 #define	SMIC_SMS		0x40
284 #define	SMIC_SMM		0x60
285 #define	SMIC_STREAM_MASK	0x60
286 
287 /*  SMIC Control Codes */
288 #define	SMIC_CC_SMS_GET_STATUS	(SMIC_CONTROL|SMIC_SMS|SMIC_GET_STATUS)
289 #define	SMIC_CC_SMS_WR_START	(SMIC_CONTROL|SMIC_SMS|SMIC_WR_START)
290 #define	SMIC_CC_SMS_WR_NEXT	(SMIC_CONTROL|SMIC_SMS|SMIC_WR_NEXT)
291 #define	SMIC_CC_SMS_WR_END	(SMIC_CONTROL|SMIC_SMS|SMIC_WR_END)
292 #define	SMIC_CC_SMS_RD_START	(SMIC_CONTROL|SMIC_SMS|SMIC_RD_START)
293 #define	SMIC_CC_SMS_RD_NEXT	(SMIC_CONTROL|SMIC_SMS|SMIC_RD_NEXT)
294 #define	SMIC_CC_SMS_RD_END	(SMIC_CONTROL|SMIC_SMS|SMIC_RD_END)
295 
296 #define	SMIC_CC_SMM_GET_STATUS	(SMIC_CONTROL|SMIC_SMM|SMIC_GET_STATUS)
297 #define	SMIC_CC_SMM_WR_START	(SMIC_CONTROL|SMIC_SMM|SMIC_WR_START)
298 #define	SMIC_CC_SMM_WR_NEXT	(SMIC_CONTROL|SMIC_SMM|SMIC_WR_NEXT)
299 #define	SMIC_CC_SMM_WR_END	(SMIC_CONTROL|SMIC_SMM|SMIC_WR_END)
300 #define	SMIC_CC_SMM_RD_START	(SMIC_CONTROL|SMIC_SMM|SMIC_RD_START)
301 #define	SMIC_CC_SMM_RD_NEXT	(SMIC_CONTROL|SMIC_SMM|SMIC_RD_NEXT)
302 #define	SMIC_CC_SMM_RD_END	(SMIC_CONTROL|SMIC_SMM|SMIC_RD_END)
303 
304 /*  SMIC Status Codes */
305 #define	SMIC_SC_SMS_READY	(SMIC_STATUS|SMIC_SMS|SMIC_READY)
306 #define	SMIC_SC_SMS_WR_START	(SMIC_STATUS|SMIC_SMS|SMIC_WR_START)
307 #define	SMIC_SC_SMS_WR_NEXT	(SMIC_STATUS|SMIC_SMS|SMIC_WR_NEXT)
308 #define	SMIC_SC_SMS_WR_END	(SMIC_STATUS|SMIC_SMS|SMIC_WR_END)
309 #define	SMIC_SC_SMS_RD_START	(SMIC_STATUS|SMIC_SMS|SMIC_RD_START)
310 #define	SMIC_SC_SMS_RD_NEXT	(SMIC_STATUS|SMIC_SMS|SMIC_RD_NEXT)
311 #define	SMIC_SC_SMS_RD_END	(SMIC_STATUS|SMIC_SMS|SMIC_RD_END)
312 
313 #define	SMIC_SC_SMM_READY	(SMIC_STATUS|SMIC_SMM|SMIC_READY)
314 #define	SMIC_SC_SMM_WR_START	(SMIC_STATUS|SMIC_SMM|SMIC_WR_START)
315 #define	SMIC_SC_SMM_WR_NEXT	(SMIC_STATUS|SMIC_SMM|SMIC_WR_NEXT)
316 #define	SMIC_SC_SMM_WR_END	(SMIC_STATUS|SMIC_SMM|SMIC_WR_END)
317 #define	SMIC_SC_SMM_RD_START	(SMIC_STATUS|SMIC_SMM|SMIC_RD_START)
318 #define	SMIC_SC_SMM_RD_NEXT	(SMIC_STATUS|SMIC_SMM|SMIC_RD_NEXT)
319 #define	SMIC_SC_SMM_RD_END	(SMIC_STATUS|SMIC_SMM|SMIC_RD_END)
320 
321 /* these are the control/status codes we actually use
322 	SMIC_CC_SMS_GET_STATUS	0x40
323 	SMIC_CC_SMS_WR_START	0x41
324 	SMIC_CC_SMS_WR_NEXT	0x42
325 	SMIC_CC_SMS_WR_END	0x43
326 	SMIC_CC_SMS_RD_START	0x44
327 	SMIC_CC_SMS_RD_NEXT	0x45
328 	SMIC_CC_SMS_RD_END	0x46
329 
330 	SMIC_SC_SMS_READY	0xC0
331 	SMIC_SC_SMS_WR_START	0xC1
332 	SMIC_SC_SMS_WR_NEXT	0xC2
333 	SMIC_SC_SMS_WR_END	0xC3
334 	SMIC_SC_SMS_RD_START	0xC4
335 	SMIC_SC_SMS_RD_NEXT	0xC5
336 	SMIC_SC_SMS_RD_END	0xC6
337 */
338 
339 static enum si_sm_result smic_event (struct si_sm_data *smic, long time)
340 {
341 	unsigned char status;
342 	unsigned char flags;
343 	unsigned char data;
344 
345 	if (smic->state == SMIC_HOSED) {
346 		init_smic_data(smic, smic->io);
347 		return SI_SM_HOSED;
348 	}
349 	if (smic->state != SMIC_IDLE) {
350 		if (smic_debug & SMIC_DEBUG_STATES) {
351 			printk(KERN_INFO
352 			       "smic_event - smic->smic_timeout = %ld,"
353 			       " time = %ld\n",
354 			       smic->smic_timeout, time);
355 		}
356 /* FIXME: smic_event is sometimes called with time > SMIC_RETRY_TIMEOUT */
357 		if (time < SMIC_RETRY_TIMEOUT) {
358 			smic->smic_timeout -= time;
359 			if (smic->smic_timeout < 0) {
360 				start_error_recovery(smic, "smic timed out.");
361 				return SI_SM_CALL_WITH_DELAY;
362 			}
363 		}
364 	}
365 	flags = read_smic_flags(smic);
366 	if (flags & SMIC_FLAG_BSY)
367 		return SI_SM_CALL_WITH_DELAY;
368 
369 	status = read_smic_status (smic);
370 	if (smic_debug & SMIC_DEBUG_STATES)
371 		printk(KERN_INFO
372 		       "smic_event - state = %d, flags = 0x%02x,"
373 		       " status = 0x%02x\n",
374 		       smic->state, flags, status);
375 
376 	switch (smic->state) {
377 	case SMIC_IDLE:
378 		/* in IDLE we check for available messages */
379 		if (flags & SMIC_SMS_DATA_AVAIL)
380 		{
381 			return SI_SM_ATTN;
382 		}
383 		return SI_SM_IDLE;
384 
385 	case SMIC_START_OP:
386 		/* sanity check whether smic is really idle */
387 		write_smic_control(smic, SMIC_CC_SMS_GET_STATUS);
388 		write_smic_flags(smic, flags | SMIC_FLAG_BSY);
389 		smic->state = SMIC_OP_OK;
390 		break;
391 
392 	case SMIC_OP_OK:
393 		if (status != SMIC_SC_SMS_READY) {
394 				/* this should not happen */
395 			start_error_recovery(smic,
396 					     "state = SMIC_OP_OK,"
397 					     " status != SMIC_SC_SMS_READY");
398 			return SI_SM_CALL_WITH_DELAY;
399 		}
400 		/* OK so far; smic is idle let us start ... */
401 		write_smic_control(smic, SMIC_CC_SMS_WR_START);
402 		write_next_byte(smic);
403 		write_smic_flags(smic, flags | SMIC_FLAG_BSY);
404 		smic->state = SMIC_WRITE_START;
405 		break;
406 
407 	case SMIC_WRITE_START:
408 		if (status != SMIC_SC_SMS_WR_START) {
409 			start_error_recovery(smic,
410 					     "state = SMIC_WRITE_START, "
411 					     "status != SMIC_SC_SMS_WR_START");
412 			return SI_SM_CALL_WITH_DELAY;
413 		}
414 		/* we must not issue WR_(NEXT|END) unless
415                    TX_DATA_READY is set */
416 		if (flags & SMIC_TX_DATA_READY) {
417 			if (smic->write_count == 1) {
418 				/* last byte */
419 				write_smic_control(smic, SMIC_CC_SMS_WR_END);
420 				smic->state = SMIC_WRITE_END;
421 			} else {
422 				write_smic_control(smic, SMIC_CC_SMS_WR_NEXT);
423 				smic->state = SMIC_WRITE_NEXT;
424 			}
425 			write_next_byte(smic);
426 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
427 		}
428 		else {
429 			return SI_SM_CALL_WITH_DELAY;
430 		}
431 		break;
432 
433 	case SMIC_WRITE_NEXT:
434 		if (status != SMIC_SC_SMS_WR_NEXT) {
435 			start_error_recovery(smic,
436 					     "state = SMIC_WRITE_NEXT, "
437 					     "status != SMIC_SC_SMS_WR_NEXT");
438 			return SI_SM_CALL_WITH_DELAY;
439 		}
440 		/* this is the same code as in SMIC_WRITE_START */
441 		if (flags & SMIC_TX_DATA_READY) {
442 			if (smic->write_count == 1) {
443 				write_smic_control(smic, SMIC_CC_SMS_WR_END);
444 				smic->state = SMIC_WRITE_END;
445 			}
446 			else {
447 				write_smic_control(smic, SMIC_CC_SMS_WR_NEXT);
448 				smic->state = SMIC_WRITE_NEXT;
449 			}
450 			write_next_byte(smic);
451 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
452 		}
453 		else {
454 			return SI_SM_CALL_WITH_DELAY;
455 		}
456 		break;
457 
458 	case SMIC_WRITE_END:
459 		if (status != SMIC_SC_SMS_WR_END) {
460 			start_error_recovery (smic,
461 					      "state = SMIC_WRITE_END, "
462 					      "status != SMIC_SC_SMS_WR_END");
463 			return SI_SM_CALL_WITH_DELAY;
464 		}
465 		/* data register holds an error code */
466 		data = read_smic_data(smic);
467 		if (data != 0) {
468 			if (smic_debug & SMIC_DEBUG_ENABLE) {
469 				printk(KERN_INFO
470 				       "SMIC_WRITE_END: data = %02x\n", data);
471 			}
472 			start_error_recovery(smic,
473 					     "state = SMIC_WRITE_END, "
474 					     "data != SUCCESS");
475 			return SI_SM_CALL_WITH_DELAY;
476 		} else {
477 			smic->state = SMIC_WRITE2READ;
478 		}
479 		break;
480 
481 	case SMIC_WRITE2READ:
482 		/* we must wait for RX_DATA_READY to be set before we
483                    can continue */
484 		if (flags & SMIC_RX_DATA_READY) {
485 			write_smic_control(smic, SMIC_CC_SMS_RD_START);
486 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
487 			smic->state = SMIC_READ_START;
488 		} else {
489 			return SI_SM_CALL_WITH_DELAY;
490 		}
491 		break;
492 
493 	case SMIC_READ_START:
494 		if (status != SMIC_SC_SMS_RD_START) {
495 			start_error_recovery(smic,
496 					     "state = SMIC_READ_START, "
497 					     "status != SMIC_SC_SMS_RD_START");
498 			return SI_SM_CALL_WITH_DELAY;
499 		}
500 		if (flags & SMIC_RX_DATA_READY) {
501 			read_next_byte(smic);
502 			write_smic_control(smic, SMIC_CC_SMS_RD_NEXT);
503 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
504 			smic->state = SMIC_READ_NEXT;
505 		} else {
506 			return SI_SM_CALL_WITH_DELAY;
507 		}
508 		break;
509 
510 	case SMIC_READ_NEXT:
511 		switch (status) {
512 		/* smic tells us that this is the last byte to be read
513                    --> clean up */
514 		case SMIC_SC_SMS_RD_END:
515 			read_next_byte(smic);
516 			write_smic_control(smic, SMIC_CC_SMS_RD_END);
517 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
518 			smic->state = SMIC_READ_END;
519 			break;
520 		case SMIC_SC_SMS_RD_NEXT:
521 			if (flags & SMIC_RX_DATA_READY) {
522 				read_next_byte(smic);
523 				write_smic_control(smic, SMIC_CC_SMS_RD_NEXT);
524 				write_smic_flags(smic, flags | SMIC_FLAG_BSY);
525 				smic->state = SMIC_READ_NEXT;
526 			} else {
527 				return SI_SM_CALL_WITH_DELAY;
528 			}
529 			break;
530 		default:
531 			start_error_recovery(
532 				smic,
533 				"state = SMIC_READ_NEXT, "
534 				"status != SMIC_SC_SMS_RD_(NEXT|END)");
535 			return SI_SM_CALL_WITH_DELAY;
536 		}
537 		break;
538 
539 	case SMIC_READ_END:
540 		if (status != SMIC_SC_SMS_READY) {
541 			start_error_recovery(smic,
542 					     "state = SMIC_READ_END, "
543 					     "status != SMIC_SC_SMS_READY");
544 			return SI_SM_CALL_WITH_DELAY;
545 		}
546 		data = read_smic_data(smic);
547 		/* data register holds an error code */
548 		if (data != 0) {
549 			if (smic_debug & SMIC_DEBUG_ENABLE) {
550 				printk(KERN_INFO
551 				       "SMIC_READ_END: data = %02x\n", data);
552 			}
553 			start_error_recovery(smic,
554 					     "state = SMIC_READ_END, "
555 					     "data != SUCCESS");
556 			return SI_SM_CALL_WITH_DELAY;
557 		} else {
558 			smic->state = SMIC_IDLE;
559 			return SI_SM_TRANSACTION_COMPLETE;
560 		}
561 
562 	case SMIC_HOSED:
563 		init_smic_data(smic, smic->io);
564 		return SI_SM_HOSED;
565 
566 	default:
567 		if (smic_debug & SMIC_DEBUG_ENABLE) {
568 			printk(KERN_WARNING "smic->state = %d\n", smic->state);
569 			start_error_recovery(smic, "state = UNKNOWN");
570 			return SI_SM_CALL_WITH_DELAY;
571 		}
572 	}
573 	smic->smic_timeout = SMIC_RETRY_TIMEOUT;
574 	return SI_SM_CALL_WITHOUT_DELAY;
575 }
576 
577 static int smic_detect(struct si_sm_data *smic)
578 {
579 	/* It's impossible for the SMIC fnags register to be all 1's,
580 	   (assuming a properly functioning, self-initialized BMC)
581 	   but that's what you get from reading a bogus address, so we
582 	   test that first. */
583 	if (read_smic_flags(smic) == 0xff)
584 		return 1;
585 
586 	return 0;
587 }
588 
589 static void smic_cleanup(struct si_sm_data *kcs)
590 {
591 }
592 
593 static int smic_size(void)
594 {
595 	return sizeof(struct si_sm_data);
596 }
597 
598 struct si_sm_handlers smic_smi_handlers =
599 {
600 	.init_data         = init_smic_data,
601 	.start_transaction = start_smic_transaction,
602 	.get_result        = smic_get_result,
603 	.event             = smic_event,
604 	.detect            = smic_detect,
605 	.cleanup           = smic_cleanup,
606 	.size              = smic_size,
607 };
608