xref: /linux/drivers/char/ipmi/ipmi_smic_sm.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
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) || (size > MAX_SMIC_WRITE_SIZE)) {
145 		return -1;
146 	}
147 	if ((smic->state != SMIC_IDLE) && (smic->state != SMIC_HOSED)) {
148 		return -2;
149 	}
150 	if (smic_debug & SMIC_DEBUG_MSG) {
151 		printk(KERN_INFO "start_smic_transaction -");
152 		for (i = 0; i < size; i ++) {
153 			printk (" %02x", (unsigned char) (data [i]));
154 		}
155 		printk ("\n");
156 	}
157 	smic->error_retries = 0;
158 	memcpy(smic->write_data, data, size);
159 	smic->write_count = size;
160 	smic->orig_write_count = size;
161 	smic->write_pos = 0;
162 	smic->read_pos = 0;
163 	smic->state = SMIC_START_OP;
164 	smic->smic_timeout = SMIC_RETRY_TIMEOUT;
165 	return 0;
166 }
167 
168 static int smic_get_result(struct si_sm_data *smic,
169 			   unsigned char *data, unsigned int length)
170 {
171 	int i;
172 
173 	if (smic_debug & SMIC_DEBUG_MSG) {
174 		printk (KERN_INFO "smic_get result -");
175 		for (i = 0; i < smic->read_pos; i ++) {
176 			printk (" %02x", (smic->read_data [i]));
177 		}
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 		}
238 		smic->state = SMIC_HOSED;
239 	} else {
240 		smic->write_count = smic->orig_write_count;
241 		smic->write_pos = 0;
242 		smic->read_pos = 0;
243 		smic->state = SMIC_START_OP;
244 		smic->smic_timeout = SMIC_RETRY_TIMEOUT;
245 	}
246 }
247 
248 static inline void write_next_byte(struct si_sm_data *smic)
249 {
250 	write_si_sm_data(smic, smic->write_data[smic->write_pos]);
251 	(smic->write_pos)++;
252 	(smic->write_count)--;
253 }
254 
255 static inline void read_next_byte (struct si_sm_data *smic)
256 {
257 	if (smic->read_pos >= MAX_SMIC_READ_SIZE) {
258 		read_smic_data (smic);
259 		smic->truncated = 1;
260 	} else {
261 		smic->read_data[smic->read_pos] = read_smic_data(smic);
262 		(smic->read_pos)++;
263 	}
264 }
265 
266 /*  SMIC Control/Status Code Components */
267 #define	SMIC_GET_STATUS		0x00	/* Control form's name */
268 #define	SMIC_READY		0x00	/* Status  form's name */
269 #define	SMIC_WR_START		0x01	/* Unified Control/Status names... */
270 #define	SMIC_WR_NEXT		0x02
271 #define	SMIC_WR_END		0x03
272 #define	SMIC_RD_START		0x04
273 #define	SMIC_RD_NEXT		0x05
274 #define	SMIC_RD_END		0x06
275 #define	SMIC_CODE_MASK		0x0f
276 
277 #define	SMIC_CONTROL		0x00
278 #define	SMIC_STATUS		0x80
279 #define	SMIC_CS_MASK		0x80
280 
281 #define	SMIC_SMS		0x40
282 #define	SMIC_SMM		0x60
283 #define	SMIC_STREAM_MASK	0x60
284 
285 /*  SMIC Control Codes */
286 #define	SMIC_CC_SMS_GET_STATUS	(SMIC_CONTROL|SMIC_SMS|SMIC_GET_STATUS)
287 #define	SMIC_CC_SMS_WR_START	(SMIC_CONTROL|SMIC_SMS|SMIC_WR_START)
288 #define	SMIC_CC_SMS_WR_NEXT	(SMIC_CONTROL|SMIC_SMS|SMIC_WR_NEXT)
289 #define	SMIC_CC_SMS_WR_END	(SMIC_CONTROL|SMIC_SMS|SMIC_WR_END)
290 #define	SMIC_CC_SMS_RD_START	(SMIC_CONTROL|SMIC_SMS|SMIC_RD_START)
291 #define	SMIC_CC_SMS_RD_NEXT	(SMIC_CONTROL|SMIC_SMS|SMIC_RD_NEXT)
292 #define	SMIC_CC_SMS_RD_END	(SMIC_CONTROL|SMIC_SMS|SMIC_RD_END)
293 
294 #define	SMIC_CC_SMM_GET_STATUS	(SMIC_CONTROL|SMIC_SMM|SMIC_GET_STATUS)
295 #define	SMIC_CC_SMM_WR_START	(SMIC_CONTROL|SMIC_SMM|SMIC_WR_START)
296 #define	SMIC_CC_SMM_WR_NEXT	(SMIC_CONTROL|SMIC_SMM|SMIC_WR_NEXT)
297 #define	SMIC_CC_SMM_WR_END	(SMIC_CONTROL|SMIC_SMM|SMIC_WR_END)
298 #define	SMIC_CC_SMM_RD_START	(SMIC_CONTROL|SMIC_SMM|SMIC_RD_START)
299 #define	SMIC_CC_SMM_RD_NEXT	(SMIC_CONTROL|SMIC_SMM|SMIC_RD_NEXT)
300 #define	SMIC_CC_SMM_RD_END	(SMIC_CONTROL|SMIC_SMM|SMIC_RD_END)
301 
302 /*  SMIC Status Codes */
303 #define	SMIC_SC_SMS_READY	(SMIC_STATUS|SMIC_SMS|SMIC_READY)
304 #define	SMIC_SC_SMS_WR_START	(SMIC_STATUS|SMIC_SMS|SMIC_WR_START)
305 #define	SMIC_SC_SMS_WR_NEXT	(SMIC_STATUS|SMIC_SMS|SMIC_WR_NEXT)
306 #define	SMIC_SC_SMS_WR_END	(SMIC_STATUS|SMIC_SMS|SMIC_WR_END)
307 #define	SMIC_SC_SMS_RD_START	(SMIC_STATUS|SMIC_SMS|SMIC_RD_START)
308 #define	SMIC_SC_SMS_RD_NEXT	(SMIC_STATUS|SMIC_SMS|SMIC_RD_NEXT)
309 #define	SMIC_SC_SMS_RD_END	(SMIC_STATUS|SMIC_SMS|SMIC_RD_END)
310 
311 #define	SMIC_SC_SMM_READY	(SMIC_STATUS|SMIC_SMM|SMIC_READY)
312 #define	SMIC_SC_SMM_WR_START	(SMIC_STATUS|SMIC_SMM|SMIC_WR_START)
313 #define	SMIC_SC_SMM_WR_NEXT	(SMIC_STATUS|SMIC_SMM|SMIC_WR_NEXT)
314 #define	SMIC_SC_SMM_WR_END	(SMIC_STATUS|SMIC_SMM|SMIC_WR_END)
315 #define	SMIC_SC_SMM_RD_START	(SMIC_STATUS|SMIC_SMM|SMIC_RD_START)
316 #define	SMIC_SC_SMM_RD_NEXT	(SMIC_STATUS|SMIC_SMM|SMIC_RD_NEXT)
317 #define	SMIC_SC_SMM_RD_END	(SMIC_STATUS|SMIC_SMM|SMIC_RD_END)
318 
319 /* these are the control/status codes we actually use
320 	SMIC_CC_SMS_GET_STATUS	0x40
321 	SMIC_CC_SMS_WR_START	0x41
322 	SMIC_CC_SMS_WR_NEXT	0x42
323 	SMIC_CC_SMS_WR_END	0x43
324 	SMIC_CC_SMS_RD_START	0x44
325 	SMIC_CC_SMS_RD_NEXT	0x45
326 	SMIC_CC_SMS_RD_END	0x46
327 
328 	SMIC_SC_SMS_READY	0xC0
329 	SMIC_SC_SMS_WR_START	0xC1
330 	SMIC_SC_SMS_WR_NEXT	0xC2
331 	SMIC_SC_SMS_WR_END	0xC3
332 	SMIC_SC_SMS_RD_START	0xC4
333 	SMIC_SC_SMS_RD_NEXT	0xC5
334 	SMIC_SC_SMS_RD_END	0xC6
335 */
336 
337 static enum si_sm_result smic_event (struct si_sm_data *smic, long time)
338 {
339 	unsigned char status;
340 	unsigned char flags;
341 	unsigned char data;
342 
343 	if (smic->state == SMIC_HOSED) {
344 		init_smic_data(smic, smic->io);
345 		return SI_SM_HOSED;
346 	}
347 	if (smic->state != SMIC_IDLE) {
348 		if (smic_debug & SMIC_DEBUG_STATES) {
349 			printk(KERN_INFO
350 			       "smic_event - smic->smic_timeout = %ld,"
351 			       " time = %ld\n",
352 			       smic->smic_timeout, time);
353 		}
354 /* FIXME: smic_event is sometimes called with time > SMIC_RETRY_TIMEOUT */
355 		if (time < SMIC_RETRY_TIMEOUT) {
356 			smic->smic_timeout -= time;
357 			if (smic->smic_timeout < 0) {
358 				start_error_recovery(smic, "smic timed out.");
359 				return SI_SM_CALL_WITH_DELAY;
360 			}
361 		}
362 	}
363 	flags = read_smic_flags(smic);
364 	if (flags & SMIC_FLAG_BSY)
365 		return SI_SM_CALL_WITH_DELAY;
366 
367 	status = read_smic_status (smic);
368 	if (smic_debug & SMIC_DEBUG_STATES)
369 		printk(KERN_INFO
370 		       "smic_event - state = %d, flags = 0x%02x,"
371 		       " status = 0x%02x\n",
372 		       smic->state, flags, status);
373 
374 	switch (smic->state) {
375 	case SMIC_IDLE:
376 		/* in IDLE we check for available messages */
377 		if (flags & SMIC_SMS_DATA_AVAIL)
378 		{
379 			return SI_SM_ATTN;
380 		}
381 		return SI_SM_IDLE;
382 
383 	case SMIC_START_OP:
384 		/* sanity check whether smic is really idle */
385 		write_smic_control(smic, SMIC_CC_SMS_GET_STATUS);
386 		write_smic_flags(smic, flags | SMIC_FLAG_BSY);
387 		smic->state = SMIC_OP_OK;
388 		break;
389 
390 	case SMIC_OP_OK:
391 		if (status != SMIC_SC_SMS_READY) {
392 				/* this should not happen */
393 			start_error_recovery(smic,
394 					     "state = SMIC_OP_OK,"
395 					     " status != SMIC_SC_SMS_READY");
396 			return SI_SM_CALL_WITH_DELAY;
397 		}
398 		/* OK so far; smic is idle let us start ... */
399 		write_smic_control(smic, SMIC_CC_SMS_WR_START);
400 		write_next_byte(smic);
401 		write_smic_flags(smic, flags | SMIC_FLAG_BSY);
402 		smic->state = SMIC_WRITE_START;
403 		break;
404 
405 	case SMIC_WRITE_START:
406 		if (status != SMIC_SC_SMS_WR_START) {
407 			start_error_recovery(smic,
408 					     "state = SMIC_WRITE_START, "
409 					     "status != SMIC_SC_SMS_WR_START");
410 			return SI_SM_CALL_WITH_DELAY;
411 		}
412 		/* we must not issue WR_(NEXT|END) unless
413                    TX_DATA_READY is set */
414 		if (flags & SMIC_TX_DATA_READY) {
415 			if (smic->write_count == 1) {
416 				/* last byte */
417 				write_smic_control(smic, SMIC_CC_SMS_WR_END);
418 				smic->state = SMIC_WRITE_END;
419 			} else {
420 				write_smic_control(smic, SMIC_CC_SMS_WR_NEXT);
421 				smic->state = SMIC_WRITE_NEXT;
422 			}
423 			write_next_byte(smic);
424 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
425 		}
426 		else {
427 			return SI_SM_CALL_WITH_DELAY;
428 		}
429 		break;
430 
431 	case SMIC_WRITE_NEXT:
432 		if (status != SMIC_SC_SMS_WR_NEXT) {
433 			start_error_recovery(smic,
434 					     "state = SMIC_WRITE_NEXT, "
435 					     "status != SMIC_SC_SMS_WR_NEXT");
436 			return SI_SM_CALL_WITH_DELAY;
437 		}
438 		/* this is the same code as in SMIC_WRITE_START */
439 		if (flags & SMIC_TX_DATA_READY) {
440 			if (smic->write_count == 1) {
441 				write_smic_control(smic, SMIC_CC_SMS_WR_END);
442 				smic->state = SMIC_WRITE_END;
443 			}
444 			else {
445 				write_smic_control(smic, SMIC_CC_SMS_WR_NEXT);
446 				smic->state = SMIC_WRITE_NEXT;
447 			}
448 			write_next_byte(smic);
449 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
450 		}
451 		else {
452 			return SI_SM_CALL_WITH_DELAY;
453 		}
454 		break;
455 
456 	case SMIC_WRITE_END:
457 		if (status != SMIC_SC_SMS_WR_END) {
458 			start_error_recovery (smic,
459 					      "state = SMIC_WRITE_END, "
460 					      "status != SMIC_SC_SMS_WR_END");
461 			return SI_SM_CALL_WITH_DELAY;
462 		}
463 		/* data register holds an error code */
464 		data = read_smic_data(smic);
465 		if (data != 0) {
466 			if (smic_debug & SMIC_DEBUG_ENABLE) {
467 				printk(KERN_INFO
468 				       "SMIC_WRITE_END: data = %02x\n", data);
469 			}
470 			start_error_recovery(smic,
471 					     "state = SMIC_WRITE_END, "
472 					     "data != SUCCESS");
473 			return SI_SM_CALL_WITH_DELAY;
474 		} else {
475 			smic->state = SMIC_WRITE2READ;
476 		}
477 		break;
478 
479 	case SMIC_WRITE2READ:
480 		/* we must wait for RX_DATA_READY to be set before we
481                    can continue */
482 		if (flags & SMIC_RX_DATA_READY) {
483 			write_smic_control(smic, SMIC_CC_SMS_RD_START);
484 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
485 			smic->state = SMIC_READ_START;
486 		} else {
487 			return SI_SM_CALL_WITH_DELAY;
488 		}
489 		break;
490 
491 	case SMIC_READ_START:
492 		if (status != SMIC_SC_SMS_RD_START) {
493 			start_error_recovery(smic,
494 					     "state = SMIC_READ_START, "
495 					     "status != SMIC_SC_SMS_RD_START");
496 			return SI_SM_CALL_WITH_DELAY;
497 		}
498 		if (flags & SMIC_RX_DATA_READY) {
499 			read_next_byte(smic);
500 			write_smic_control(smic, SMIC_CC_SMS_RD_NEXT);
501 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
502 			smic->state = SMIC_READ_NEXT;
503 		} else {
504 			return SI_SM_CALL_WITH_DELAY;
505 		}
506 		break;
507 
508 	case SMIC_READ_NEXT:
509 		switch (status) {
510 		/* smic tells us that this is the last byte to be read
511                    --> clean up */
512 		case SMIC_SC_SMS_RD_END:
513 			read_next_byte(smic);
514 			write_smic_control(smic, SMIC_CC_SMS_RD_END);
515 			write_smic_flags(smic, flags | SMIC_FLAG_BSY);
516 			smic->state = SMIC_READ_END;
517 			break;
518 		case SMIC_SC_SMS_RD_NEXT:
519 			if (flags & SMIC_RX_DATA_READY) {
520 				read_next_byte(smic);
521 				write_smic_control(smic, SMIC_CC_SMS_RD_NEXT);
522 				write_smic_flags(smic, flags | SMIC_FLAG_BSY);
523 				smic->state = SMIC_READ_NEXT;
524 			} else {
525 				return SI_SM_CALL_WITH_DELAY;
526 			}
527 			break;
528 		default:
529 			start_error_recovery(
530 				smic,
531 				"state = SMIC_READ_NEXT, "
532 				"status != SMIC_SC_SMS_RD_(NEXT|END)");
533 			return SI_SM_CALL_WITH_DELAY;
534 		}
535 		break;
536 
537 	case SMIC_READ_END:
538 		if (status != SMIC_SC_SMS_READY) {
539 			start_error_recovery(smic,
540 					     "state = SMIC_READ_END, "
541 					     "status != SMIC_SC_SMS_READY");
542 			return SI_SM_CALL_WITH_DELAY;
543 		}
544 		data = read_smic_data(smic);
545 		/* data register holds an error code */
546 		if (data != 0) {
547 			if (smic_debug & SMIC_DEBUG_ENABLE) {
548 				printk(KERN_INFO
549 				       "SMIC_READ_END: data = %02x\n", data);
550 			}
551 			start_error_recovery(smic,
552 					     "state = SMIC_READ_END, "
553 					     "data != SUCCESS");
554 			return SI_SM_CALL_WITH_DELAY;
555 		} else {
556 			smic->state = SMIC_IDLE;
557 			return SI_SM_TRANSACTION_COMPLETE;
558 		}
559 
560 	case SMIC_HOSED:
561 		init_smic_data(smic, smic->io);
562 		return SI_SM_HOSED;
563 
564 	default:
565 		if (smic_debug & SMIC_DEBUG_ENABLE) {
566 			printk(KERN_WARNING "smic->state = %d\n", smic->state);
567 			start_error_recovery(smic, "state = UNKNOWN");
568 			return SI_SM_CALL_WITH_DELAY;
569 		}
570 	}
571 	smic->smic_timeout = SMIC_RETRY_TIMEOUT;
572 	return SI_SM_CALL_WITHOUT_DELAY;
573 }
574 
575 static int smic_detect(struct si_sm_data *smic)
576 {
577 	/* It's impossible for the SMIC fnags register to be all 1's,
578 	   (assuming a properly functioning, self-initialized BMC)
579 	   but that's what you get from reading a bogus address, so we
580 	   test that first. */
581 	if (read_smic_flags(smic) == 0xff)
582 		return 1;
583 
584 	return 0;
585 }
586 
587 static void smic_cleanup(struct si_sm_data *kcs)
588 {
589 }
590 
591 static int smic_size(void)
592 {
593 	return sizeof(struct si_sm_data);
594 }
595 
596 struct si_sm_handlers smic_smi_handlers =
597 {
598 	.init_data         = init_smic_data,
599 	.start_transaction = start_smic_transaction,
600 	.get_result        = smic_get_result,
601 	.event             = smic_event,
602 	.detect            = smic_detect,
603 	.cleanup           = smic_cleanup,
604 	.size              = smic_size,
605 };
606