xref: /openbmc/linux/drivers/char/ipmi/ipmi_smic_sm.c (revision e3b9f1e8)
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 (2*USEC_PER_SEC)
84 
85 /* SMIC Flags Register Bits */
86 #define SMIC_RX_DATA_READY	0x80
87 #define SMIC_TX_DATA_READY	0x40
88 
89 /*
90  * SMIC_SMI and SMIC_EVM_DATA_AVAIL are only used by
91  * a few systems, and then only by Systems Management
92  * Interrupts, not by the OS.  Always ignore these bits.
93  *
94  */
95 #define SMIC_SMI		0x10
96 #define SMIC_EVM_DATA_AVAIL	0x08
97 #define SMIC_SMS_DATA_AVAIL	0x04
98 #define SMIC_FLAG_BSY		0x01
99 
100 /* SMIC Error Codes */
101 #define	EC_NO_ERROR		0x00
102 #define	EC_ABORTED		0x01
103 #define	EC_ILLEGAL_CONTROL	0x02
104 #define	EC_NO_RESPONSE		0x03
105 #define	EC_ILLEGAL_COMMAND	0x04
106 #define	EC_BUFFER_FULL		0x05
107 
108 struct si_sm_data {
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_DEBUG "start_smic_transaction -");
154 		for (i = 0; i < size; i++)
155 			printk(" %02x", (unsigned char) data[i]);
156 		printk("\n");
157 	}
158 	smic->error_retries = 0;
159 	memcpy(smic->write_data, data, size);
160 	smic->write_count = size;
161 	smic->orig_write_count = size;
162 	smic->write_pos = 0;
163 	smic->read_pos = 0;
164 	smic->state = SMIC_START_OP;
165 	smic->smic_timeout = SMIC_RETRY_TIMEOUT;
166 	return 0;
167 }
168 
169 static int smic_get_result(struct si_sm_data *smic,
170 			   unsigned char *data, unsigned int length)
171 {
172 	int i;
173 
174 	if (smic_debug & SMIC_DEBUG_MSG) {
175 		printk(KERN_DEBUG "smic_get result -");
176 		for (i = 0; i < smic->read_pos; i++)
177 			printk(" %02x", smic->read_data[i]);
178 		printk("\n");
179 	}
180 	if (length < smic->read_pos) {
181 		smic->read_pos = length;
182 		smic->truncated = 1;
183 	}
184 	memcpy(data, smic->read_data, smic->read_pos);
185 
186 	if ((length >= 3) && (smic->read_pos < 3)) {
187 		data[2] = IPMI_ERR_UNSPECIFIED;
188 		smic->read_pos = 3;
189 	}
190 	if (smic->truncated) {
191 		data[2] = IPMI_ERR_MSG_TRUNCATED;
192 		smic->truncated = 0;
193 	}
194 	return smic->read_pos;
195 }
196 
197 static inline unsigned char read_smic_flags(struct si_sm_data *smic)
198 {
199 	return smic->io->inputb(smic->io, 2);
200 }
201 
202 static inline unsigned char read_smic_status(struct si_sm_data *smic)
203 {
204 	return smic->io->inputb(smic->io, 1);
205 }
206 
207 static inline unsigned char read_smic_data(struct si_sm_data *smic)
208 {
209 	return smic->io->inputb(smic->io, 0);
210 }
211 
212 static inline void write_smic_flags(struct si_sm_data *smic,
213 				    unsigned char   flags)
214 {
215 	smic->io->outputb(smic->io, 2, flags);
216 }
217 
218 static inline void write_smic_control(struct si_sm_data *smic,
219 				      unsigned char   control)
220 {
221 	smic->io->outputb(smic->io, 1, control);
222 }
223 
224 static inline void write_si_sm_data(struct si_sm_data *smic,
225 				    unsigned char   data)
226 {
227 	smic->io->outputb(smic->io, 0, data);
228 }
229 
230 static inline void start_error_recovery(struct si_sm_data *smic, char *reason)
231 {
232 	(smic->error_retries)++;
233 	if (smic->error_retries > SMIC_MAX_ERROR_RETRIES) {
234 		if (smic_debug & SMIC_DEBUG_ENABLE)
235 			printk(KERN_WARNING
236 			       "ipmi_smic_drv: smic hosed: %s\n", reason);
237 		smic->state = SMIC_HOSED;
238 	} else {
239 		smic->write_count = smic->orig_write_count;
240 		smic->write_pos = 0;
241 		smic->read_pos = 0;
242 		smic->state = SMIC_START_OP;
243 		smic->smic_timeout = SMIC_RETRY_TIMEOUT;
244 	}
245 }
246 
247 static inline void write_next_byte(struct si_sm_data *smic)
248 {
249 	write_si_sm_data(smic, smic->write_data[smic->write_pos]);
250 	(smic->write_pos)++;
251 	(smic->write_count)--;
252 }
253 
254 static inline void read_next_byte(struct si_sm_data *smic)
255 {
256 	if (smic->read_pos >= MAX_SMIC_READ_SIZE) {
257 		read_smic_data(smic);
258 		smic->truncated = 1;
259 	} else {
260 		smic->read_data[smic->read_pos] = read_smic_data(smic);
261 		smic->read_pos++;
262 	}
263 }
264 
265 /*  SMIC Control/Status Code Components */
266 #define	SMIC_GET_STATUS		0x00	/* Control form's name */
267 #define	SMIC_READY		0x00	/* Status  form's name */
268 #define	SMIC_WR_START		0x01	/* Unified Control/Status names... */
269 #define	SMIC_WR_NEXT		0x02
270 #define	SMIC_WR_END		0x03
271 #define	SMIC_RD_START		0x04
272 #define	SMIC_RD_NEXT		0x05
273 #define	SMIC_RD_END		0x06
274 #define	SMIC_CODE_MASK		0x0f
275 
276 #define	SMIC_CONTROL		0x00
277 #define	SMIC_STATUS		0x80
278 #define	SMIC_CS_MASK		0x80
279 
280 #define	SMIC_SMS		0x40
281 #define	SMIC_SMM		0x60
282 #define	SMIC_STREAM_MASK	0x60
283 
284 /*  SMIC Control Codes */
285 #define	SMIC_CC_SMS_GET_STATUS	(SMIC_CONTROL|SMIC_SMS|SMIC_GET_STATUS)
286 #define	SMIC_CC_SMS_WR_START	(SMIC_CONTROL|SMIC_SMS|SMIC_WR_START)
287 #define	SMIC_CC_SMS_WR_NEXT	(SMIC_CONTROL|SMIC_SMS|SMIC_WR_NEXT)
288 #define	SMIC_CC_SMS_WR_END	(SMIC_CONTROL|SMIC_SMS|SMIC_WR_END)
289 #define	SMIC_CC_SMS_RD_START	(SMIC_CONTROL|SMIC_SMS|SMIC_RD_START)
290 #define	SMIC_CC_SMS_RD_NEXT	(SMIC_CONTROL|SMIC_SMS|SMIC_RD_NEXT)
291 #define	SMIC_CC_SMS_RD_END	(SMIC_CONTROL|SMIC_SMS|SMIC_RD_END)
292 
293 #define	SMIC_CC_SMM_GET_STATUS	(SMIC_CONTROL|SMIC_SMM|SMIC_GET_STATUS)
294 #define	SMIC_CC_SMM_WR_START	(SMIC_CONTROL|SMIC_SMM|SMIC_WR_START)
295 #define	SMIC_CC_SMM_WR_NEXT	(SMIC_CONTROL|SMIC_SMM|SMIC_WR_NEXT)
296 #define	SMIC_CC_SMM_WR_END	(SMIC_CONTROL|SMIC_SMM|SMIC_WR_END)
297 #define	SMIC_CC_SMM_RD_START	(SMIC_CONTROL|SMIC_SMM|SMIC_RD_START)
298 #define	SMIC_CC_SMM_RD_NEXT	(SMIC_CONTROL|SMIC_SMM|SMIC_RD_NEXT)
299 #define	SMIC_CC_SMM_RD_END	(SMIC_CONTROL|SMIC_SMM|SMIC_RD_END)
300 
301 /*  SMIC Status Codes */
302 #define	SMIC_SC_SMS_READY	(SMIC_STATUS|SMIC_SMS|SMIC_READY)
303 #define	SMIC_SC_SMS_WR_START	(SMIC_STATUS|SMIC_SMS|SMIC_WR_START)
304 #define	SMIC_SC_SMS_WR_NEXT	(SMIC_STATUS|SMIC_SMS|SMIC_WR_NEXT)
305 #define	SMIC_SC_SMS_WR_END	(SMIC_STATUS|SMIC_SMS|SMIC_WR_END)
306 #define	SMIC_SC_SMS_RD_START	(SMIC_STATUS|SMIC_SMS|SMIC_RD_START)
307 #define	SMIC_SC_SMS_RD_NEXT	(SMIC_STATUS|SMIC_SMS|SMIC_RD_NEXT)
308 #define	SMIC_SC_SMS_RD_END	(SMIC_STATUS|SMIC_SMS|SMIC_RD_END)
309 
310 #define	SMIC_SC_SMM_READY	(SMIC_STATUS|SMIC_SMM|SMIC_READY)
311 #define	SMIC_SC_SMM_WR_START	(SMIC_STATUS|SMIC_SMM|SMIC_WR_START)
312 #define	SMIC_SC_SMM_WR_NEXT	(SMIC_STATUS|SMIC_SMM|SMIC_WR_NEXT)
313 #define	SMIC_SC_SMM_WR_END	(SMIC_STATUS|SMIC_SMM|SMIC_WR_END)
314 #define	SMIC_SC_SMM_RD_START	(SMIC_STATUS|SMIC_SMM|SMIC_RD_START)
315 #define	SMIC_SC_SMM_RD_NEXT	(SMIC_STATUS|SMIC_SMM|SMIC_RD_NEXT)
316 #define	SMIC_SC_SMM_RD_END	(SMIC_STATUS|SMIC_SMM|SMIC_RD_END)
317 
318 /* these are the control/status codes we actually use
319 	SMIC_CC_SMS_GET_STATUS	0x40
320 	SMIC_CC_SMS_WR_START	0x41
321 	SMIC_CC_SMS_WR_NEXT	0x42
322 	SMIC_CC_SMS_WR_END	0x43
323 	SMIC_CC_SMS_RD_START	0x44
324 	SMIC_CC_SMS_RD_NEXT	0x45
325 	SMIC_CC_SMS_RD_END	0x46
326 
327 	SMIC_SC_SMS_READY	0xC0
328 	SMIC_SC_SMS_WR_START	0xC1
329 	SMIC_SC_SMS_WR_NEXT	0xC2
330 	SMIC_SC_SMS_WR_END	0xC3
331 	SMIC_SC_SMS_RD_START	0xC4
332 	SMIC_SC_SMS_RD_NEXT	0xC5
333 	SMIC_SC_SMS_RD_END	0xC6
334 */
335 
336 static enum si_sm_result smic_event(struct si_sm_data *smic, long time)
337 {
338 	unsigned char status;
339 	unsigned char flags;
340 	unsigned char data;
341 
342 	if (smic->state == SMIC_HOSED) {
343 		init_smic_data(smic, smic->io);
344 		return SI_SM_HOSED;
345 	}
346 	if (smic->state != SMIC_IDLE) {
347 		if (smic_debug & SMIC_DEBUG_STATES)
348 			printk(KERN_DEBUG
349 			       "smic_event - smic->smic_timeout = %ld,"
350 			       " time = %ld\n",
351 			       smic->smic_timeout, time);
352 		/*
353 		 * FIXME: smic_event is sometimes called with time >
354 		 * SMIC_RETRY_TIMEOUT
355 		 */
356 		if (time < SMIC_RETRY_TIMEOUT) {
357 			smic->smic_timeout -= time;
358 			if (smic->smic_timeout < 0) {
359 				start_error_recovery(smic, "smic timed out.");
360 				return SI_SM_CALL_WITH_DELAY;
361 			}
362 		}
363 	}
364 	flags = read_smic_flags(smic);
365 	if (flags & SMIC_FLAG_BSY)
366 		return SI_SM_CALL_WITH_DELAY;
367 
368 	status = read_smic_status(smic);
369 	if (smic_debug & SMIC_DEBUG_STATES)
370 		printk(KERN_DEBUG
371 		       "smic_event - state = %d, flags = 0x%02x,"
372 		       " status = 0x%02x\n",
373 		       smic->state, flags, status);
374 
375 	switch (smic->state) {
376 	case SMIC_IDLE:
377 		/* in IDLE we check for available messages */
378 		if (flags & SMIC_SMS_DATA_AVAIL)
379 			return SI_SM_ATTN;
380 		return SI_SM_IDLE;
381 
382 	case SMIC_START_OP:
383 		/* sanity check whether smic is really idle */
384 		write_smic_control(smic, SMIC_CC_SMS_GET_STATUS);
385 		write_smic_flags(smic, flags | SMIC_FLAG_BSY);
386 		smic->state = SMIC_OP_OK;
387 		break;
388 
389 	case SMIC_OP_OK:
390 		if (status != SMIC_SC_SMS_READY) {
391 			/* this should not happen */
392 			start_error_recovery(smic,
393 					     "state = SMIC_OP_OK,"
394 					     " status != SMIC_SC_SMS_READY");
395 			return SI_SM_CALL_WITH_DELAY;
396 		}
397 		/* OK so far; smic is idle let us start ... */
398 		write_smic_control(smic, SMIC_CC_SMS_WR_START);
399 		write_next_byte(smic);
400 		write_smic_flags(smic, flags | SMIC_FLAG_BSY);
401 		smic->state = SMIC_WRITE_START;
402 		break;
403 
404 	case SMIC_WRITE_START:
405 		if (status != SMIC_SC_SMS_WR_START) {
406 			start_error_recovery(smic,
407 					     "state = SMIC_WRITE_START, "
408 					     "status != SMIC_SC_SMS_WR_START");
409 			return SI_SM_CALL_WITH_DELAY;
410 		}
411 		/*
412 		 * we must not issue WR_(NEXT|END) unless
413 		 * TX_DATA_READY is set
414 		 * */
415 		if (flags & SMIC_TX_DATA_READY) {
416 			if (smic->write_count == 1) {
417 				/* last byte */
418 				write_smic_control(smic, SMIC_CC_SMS_WR_END);
419 				smic->state = SMIC_WRITE_END;
420 			} else {
421 				write_smic_control(smic, SMIC_CC_SMS_WR_NEXT);
422 				smic->state = SMIC_WRITE_NEXT;
423 			}
424 			write_next_byte(smic);
425 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
426 		} else
427 			return SI_SM_CALL_WITH_DELAY;
428 		break;
429 
430 	case SMIC_WRITE_NEXT:
431 		if (status != SMIC_SC_SMS_WR_NEXT) {
432 			start_error_recovery(smic,
433 					     "state = SMIC_WRITE_NEXT, "
434 					     "status != SMIC_SC_SMS_WR_NEXT");
435 			return SI_SM_CALL_WITH_DELAY;
436 		}
437 		/* this is the same code as in SMIC_WRITE_START */
438 		if (flags & SMIC_TX_DATA_READY) {
439 			if (smic->write_count == 1) {
440 				write_smic_control(smic, SMIC_CC_SMS_WR_END);
441 				smic->state = SMIC_WRITE_END;
442 			} else {
443 				write_smic_control(smic, SMIC_CC_SMS_WR_NEXT);
444 				smic->state = SMIC_WRITE_NEXT;
445 			}
446 			write_next_byte(smic);
447 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
448 		} else
449 			return SI_SM_CALL_WITH_DELAY;
450 		break;
451 
452 	case SMIC_WRITE_END:
453 		if (status != SMIC_SC_SMS_WR_END) {
454 			start_error_recovery(smic,
455 					     "state = SMIC_WRITE_END, "
456 					     "status != SMIC_SC_SMS_WR_END");
457 			return SI_SM_CALL_WITH_DELAY;
458 		}
459 		/* data register holds an error code */
460 		data = read_smic_data(smic);
461 		if (data != 0) {
462 			if (smic_debug & SMIC_DEBUG_ENABLE)
463 				printk(KERN_DEBUG
464 				       "SMIC_WRITE_END: data = %02x\n", data);
465 			start_error_recovery(smic,
466 					     "state = SMIC_WRITE_END, "
467 					     "data != SUCCESS");
468 			return SI_SM_CALL_WITH_DELAY;
469 		} else
470 			smic->state = SMIC_WRITE2READ;
471 		break;
472 
473 	case SMIC_WRITE2READ:
474 		/*
475 		 * we must wait for RX_DATA_READY to be set before we
476 		 * can continue
477 		 */
478 		if (flags & SMIC_RX_DATA_READY) {
479 			write_smic_control(smic, SMIC_CC_SMS_RD_START);
480 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
481 			smic->state = SMIC_READ_START;
482 		} else
483 			return SI_SM_CALL_WITH_DELAY;
484 		break;
485 
486 	case SMIC_READ_START:
487 		if (status != SMIC_SC_SMS_RD_START) {
488 			start_error_recovery(smic,
489 					     "state = SMIC_READ_START, "
490 					     "status != SMIC_SC_SMS_RD_START");
491 			return SI_SM_CALL_WITH_DELAY;
492 		}
493 		if (flags & SMIC_RX_DATA_READY) {
494 			read_next_byte(smic);
495 			write_smic_control(smic, SMIC_CC_SMS_RD_NEXT);
496 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
497 			smic->state = SMIC_READ_NEXT;
498 		} else
499 			return SI_SM_CALL_WITH_DELAY;
500 		break;
501 
502 	case SMIC_READ_NEXT:
503 		switch (status) {
504 		/*
505 		 * smic tells us that this is the last byte to be read
506 		 * --> clean up
507 		 */
508 		case SMIC_SC_SMS_RD_END:
509 			read_next_byte(smic);
510 			write_smic_control(smic, SMIC_CC_SMS_RD_END);
511 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
512 			smic->state = SMIC_READ_END;
513 			break;
514 		case SMIC_SC_SMS_RD_NEXT:
515 			if (flags & SMIC_RX_DATA_READY) {
516 				read_next_byte(smic);
517 				write_smic_control(smic, SMIC_CC_SMS_RD_NEXT);
518 				write_smic_flags(smic, flags | SMIC_FLAG_BSY);
519 				smic->state = SMIC_READ_NEXT;
520 			} else
521 				return SI_SM_CALL_WITH_DELAY;
522 			break;
523 		default:
524 			start_error_recovery(
525 				smic,
526 				"state = SMIC_READ_NEXT, "
527 				"status != SMIC_SC_SMS_RD_(NEXT|END)");
528 			return SI_SM_CALL_WITH_DELAY;
529 		}
530 		break;
531 
532 	case SMIC_READ_END:
533 		if (status != SMIC_SC_SMS_READY) {
534 			start_error_recovery(smic,
535 					     "state = SMIC_READ_END, "
536 					     "status != SMIC_SC_SMS_READY");
537 			return SI_SM_CALL_WITH_DELAY;
538 		}
539 		data = read_smic_data(smic);
540 		/* data register holds an error code */
541 		if (data != 0) {
542 			if (smic_debug & SMIC_DEBUG_ENABLE)
543 				printk(KERN_DEBUG
544 				       "SMIC_READ_END: data = %02x\n", data);
545 			start_error_recovery(smic,
546 					     "state = SMIC_READ_END, "
547 					     "data != SUCCESS");
548 			return SI_SM_CALL_WITH_DELAY;
549 		} else {
550 			smic->state = SMIC_IDLE;
551 			return SI_SM_TRANSACTION_COMPLETE;
552 		}
553 
554 	case SMIC_HOSED:
555 		init_smic_data(smic, smic->io);
556 		return SI_SM_HOSED;
557 
558 	default:
559 		if (smic_debug & SMIC_DEBUG_ENABLE) {
560 			printk(KERN_DEBUG "smic->state = %d\n", smic->state);
561 			start_error_recovery(smic, "state = UNKNOWN");
562 			return SI_SM_CALL_WITH_DELAY;
563 		}
564 	}
565 	smic->smic_timeout = SMIC_RETRY_TIMEOUT;
566 	return SI_SM_CALL_WITHOUT_DELAY;
567 }
568 
569 static int smic_detect(struct si_sm_data *smic)
570 {
571 	/*
572 	 * It's impossible for the SMIC fnags register to be all 1's,
573 	 * (assuming a properly functioning, self-initialized BMC)
574 	 * but that's what you get from reading a bogus address, so we
575 	 * test that first.
576 	 */
577 	if (read_smic_flags(smic) == 0xff)
578 		return 1;
579 
580 	return 0;
581 }
582 
583 static void smic_cleanup(struct si_sm_data *kcs)
584 {
585 }
586 
587 static int smic_size(void)
588 {
589 	return sizeof(struct si_sm_data);
590 }
591 
592 const struct si_sm_handlers smic_smi_handlers = {
593 	.init_data         = init_smic_data,
594 	.start_transaction = start_smic_transaction,
595 	.get_result        = smic_get_result,
596 	.event             = smic_event,
597 	.detect            = smic_detect,
598 	.cleanup           = smic_cleanup,
599 	.size              = smic_size,
600 };
601