xref: /linux/drivers/input/serio/hil_mlc.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1 /*
2  * HIL MLC state machine and serio interface driver
3  *
4  * Copyright (c) 2001 Brian S. Julin
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * Alternatively, this software may be distributed under the terms of the
17  * GNU General Public License ("GPL").
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
23  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  *
29  * References:
30  * HP-HIL Technical Reference Manual.  Hewlett Packard Product No. 45918A
31  *
32  *
33  *	Driver theory of operation:
34  *
35  *	Some access methods and an ISR is defined by the sub-driver
36  *	(e.g. hp_sdc_mlc.c).  These methods are expected to provide a
37  *	few bits of logic in addition to raw access to the HIL MLC,
38  *	specifically, the ISR, which is entirely registered by the
39  *	sub-driver and invoked directly, must check for record
40  *	termination or packet match, at which point a semaphore must
41  *	be cleared and then the hil_mlcs_tasklet must be scheduled.
42  *
43  *	The hil_mlcs_tasklet processes the state machine for all MLCs
44  *	each time it runs, checking each MLC's progress at the current
45  *	node in the state machine, and moving the MLC to subsequent nodes
46  *	in the state machine when appropriate.  It will reschedule
47  *	itself if output is pending.  (This rescheduling should be replaced
48  *	at some point with a sub-driver-specific mechanism.)
49  *
50  *	A timer task prods the tasklet once per second to prevent
51  *	hangups when attached devices do not return expected data
52  *	and to initiate probes of the loop for new devices.
53  */
54 
55 #include <linux/hil_mlc.h>
56 #include <linux/errno.h>
57 #include <linux/kernel.h>
58 #include <linux/module.h>
59 #include <linux/init.h>
60 #include <linux/interrupt.h>
61 #include <linux/slab.h>
62 #include <linux/timer.h>
63 #include <linux/list.h>
64 
65 MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
66 MODULE_DESCRIPTION("HIL MLC serio");
67 MODULE_LICENSE("Dual BSD/GPL");
68 
69 EXPORT_SYMBOL(hil_mlc_register);
70 EXPORT_SYMBOL(hil_mlc_unregister);
71 
72 #define PREFIX "HIL MLC: "
73 
74 static LIST_HEAD(hil_mlcs);
75 static DEFINE_RWLOCK(hil_mlcs_lock);
76 static struct timer_list	hil_mlcs_kicker;
77 static int			hil_mlcs_probe;
78 
79 static void hil_mlcs_process(unsigned long unused);
80 static DECLARE_TASKLET_DISABLED(hil_mlcs_tasklet, hil_mlcs_process, 0);
81 
82 
83 /* #define HIL_MLC_DEBUG */
84 
85 /********************** Device info/instance management **********************/
86 
87 static void hil_mlc_clear_di_map(hil_mlc *mlc, int val)
88 {
89 	int j;
90 
91 	for (j = val; j < 7 ; j++)
92 		mlc->di_map[j] = -1;
93 }
94 
95 static void hil_mlc_clear_di_scratch(hil_mlc *mlc)
96 {
97 	memset(&mlc->di_scratch, 0, sizeof(mlc->di_scratch));
98 }
99 
100 static void hil_mlc_copy_di_scratch(hil_mlc *mlc, int idx)
101 {
102 	memcpy(&mlc->di[idx], &mlc->di_scratch, sizeof(mlc->di_scratch));
103 }
104 
105 static int hil_mlc_match_di_scratch(hil_mlc *mlc)
106 {
107 	int idx;
108 
109 	for (idx = 0; idx < HIL_MLC_DEVMEM; idx++) {
110 		int j, found = 0;
111 
112 		/* In-use slots are not eligible. */
113 		for (j = 0; j < 7 ; j++)
114 			if (mlc->di_map[j] == idx)
115 				found++;
116 
117 		if (found)
118 			continue;
119 
120 		if (!memcmp(mlc->di + idx, &mlc->di_scratch,
121 				sizeof(mlc->di_scratch)))
122 			break;
123 	}
124 	return idx >= HIL_MLC_DEVMEM ? -1 : idx;
125 }
126 
127 static int hil_mlc_find_free_di(hil_mlc *mlc)
128 {
129 	int idx;
130 
131 	/* TODO: Pick all-zero slots first, failing that,
132 	 * randomize the slot picked among those eligible.
133 	 */
134 	for (idx = 0; idx < HIL_MLC_DEVMEM; idx++) {
135 		int j, found = 0;
136 
137 		for (j = 0; j < 7 ; j++)
138 			if (mlc->di_map[j] == idx)
139 				found++;
140 
141 		if (!found)
142 			break;
143 	}
144 
145 	return idx; /* Note: It is guaranteed at least one above will match */
146 }
147 
148 static inline void hil_mlc_clean_serio_map(hil_mlc *mlc)
149 {
150 	int idx;
151 
152 	for (idx = 0; idx < HIL_MLC_DEVMEM; idx++) {
153 		int j, found = 0;
154 
155 		for (j = 0; j < 7 ; j++)
156 			if (mlc->di_map[j] == idx)
157 				found++;
158 
159 		if (!found)
160 			mlc->serio_map[idx].di_revmap = -1;
161 	}
162 }
163 
164 static void hil_mlc_send_polls(hil_mlc *mlc)
165 {
166 	int did, i, cnt;
167 	struct serio *serio;
168 	struct serio_driver *drv;
169 
170 	i = cnt = 0;
171 	did = (mlc->ipacket[0] & HIL_PKT_ADDR_MASK) >> 8;
172 	serio = did ? mlc->serio[mlc->di_map[did - 1]] : NULL;
173 	drv = (serio != NULL) ? serio->drv : NULL;
174 
175 	while (mlc->icount < 15 - i) {
176 		hil_packet p;
177 
178 		p = mlc->ipacket[i];
179 		if (did != (p & HIL_PKT_ADDR_MASK) >> 8) {
180 			if (drv && drv->interrupt) {
181 				drv->interrupt(serio, 0, 0);
182 				drv->interrupt(serio, HIL_ERR_INT >> 16, 0);
183 				drv->interrupt(serio, HIL_PKT_CMD >> 8,  0);
184 				drv->interrupt(serio, HIL_CMD_POL + cnt, 0);
185 			}
186 
187 			did = (p & HIL_PKT_ADDR_MASK) >> 8;
188 			serio = did ? mlc->serio[mlc->di_map[did-1]] : NULL;
189 			drv = (serio != NULL) ? serio->drv : NULL;
190 			cnt = 0;
191 		}
192 
193 		cnt++;
194 		i++;
195 
196 		if (drv && drv->interrupt) {
197 			drv->interrupt(serio, (p >> 24), 0);
198 			drv->interrupt(serio, (p >> 16) & 0xff, 0);
199 			drv->interrupt(serio, (p >> 8) & ~HIL_PKT_ADDR_MASK, 0);
200 			drv->interrupt(serio, p & 0xff, 0);
201 		}
202 	}
203 }
204 
205 /*************************** State engine *********************************/
206 
207 #define HILSEN_SCHED	0x000100	/* Schedule the tasklet		*/
208 #define HILSEN_BREAK	0x000200	/* Wait until next pass		*/
209 #define HILSEN_UP	0x000400	/* relative node#, decrement	*/
210 #define HILSEN_DOWN	0x000800	/* relative node#, increment	*/
211 #define HILSEN_FOLLOW	0x001000	/* use retval as next node#	*/
212 
213 #define HILSEN_MASK	0x0000ff
214 #define HILSEN_START	0
215 #define HILSEN_RESTART	1
216 #define HILSEN_DHR	9
217 #define HILSEN_DHR2	10
218 #define HILSEN_IFC	14
219 #define HILSEN_HEAL0	16
220 #define HILSEN_HEAL	18
221 #define HILSEN_ACF      21
222 #define HILSEN_ACF2	22
223 #define HILSEN_DISC0	25
224 #define HILSEN_DISC	27
225 #define HILSEN_MATCH	40
226 #define HILSEN_OPERATE	41
227 #define HILSEN_PROBE	44
228 #define HILSEN_DSR	52
229 #define HILSEN_REPOLL	55
230 #define HILSEN_IFCACF	58
231 #define HILSEN_END	60
232 
233 #define HILSEN_NEXT	(HILSEN_DOWN | 1)
234 #define HILSEN_SAME	(HILSEN_DOWN | 0)
235 #define HILSEN_LAST	(HILSEN_UP | 1)
236 
237 #define HILSEN_DOZE	(HILSEN_SAME | HILSEN_SCHED | HILSEN_BREAK)
238 #define HILSEN_SLEEP	(HILSEN_SAME | HILSEN_BREAK)
239 
240 static int hilse_match(hil_mlc *mlc, int unused)
241 {
242 	int rc;
243 
244 	rc = hil_mlc_match_di_scratch(mlc);
245 	if (rc == -1) {
246 		rc = hil_mlc_find_free_di(mlc);
247 		if (rc == -1)
248 			goto err;
249 
250 #ifdef HIL_MLC_DEBUG
251 		printk(KERN_DEBUG PREFIX "new in slot %i\n", rc);
252 #endif
253 		hil_mlc_copy_di_scratch(mlc, rc);
254 		mlc->di_map[mlc->ddi] = rc;
255 		mlc->serio_map[rc].di_revmap = mlc->ddi;
256 		hil_mlc_clean_serio_map(mlc);
257 		serio_rescan(mlc->serio[rc]);
258 		return -1;
259 	}
260 
261 	mlc->di_map[mlc->ddi] = rc;
262 #ifdef HIL_MLC_DEBUG
263 	printk(KERN_DEBUG PREFIX "same in slot %i\n", rc);
264 #endif
265 	mlc->serio_map[rc].di_revmap = mlc->ddi;
266 	hil_mlc_clean_serio_map(mlc);
267 	return 0;
268 
269  err:
270 	printk(KERN_ERR PREFIX "Residual device slots exhausted, close some serios!\n");
271 	return 1;
272 }
273 
274 /* An LCV used to prevent runaway loops, forces 5 second sleep when reset. */
275 static int hilse_init_lcv(hil_mlc *mlc, int unused)
276 {
277 	time64_t now = ktime_get_seconds();
278 
279 	if (mlc->lcv && (now - mlc->lcv_time) < 5)
280 		return -1;
281 
282 	mlc->lcv_time = now;
283 	mlc->lcv = 0;
284 
285 	return 0;
286 }
287 
288 static int hilse_inc_lcv(hil_mlc *mlc, int lim)
289 {
290 	return mlc->lcv++ >= lim ? -1 : 0;
291 }
292 
293 #if 0
294 static int hilse_set_lcv(hil_mlc *mlc, int val)
295 {
296 	mlc->lcv = val;
297 
298 	return 0;
299 }
300 #endif
301 
302 /* Management of the discovered device index (zero based, -1 means no devs) */
303 static int hilse_set_ddi(hil_mlc *mlc, int val)
304 {
305 	mlc->ddi = val;
306 	hil_mlc_clear_di_map(mlc, val + 1);
307 
308 	return 0;
309 }
310 
311 static int hilse_dec_ddi(hil_mlc *mlc, int unused)
312 {
313 	mlc->ddi--;
314 	if (mlc->ddi <= -1) {
315 		mlc->ddi = -1;
316 		hil_mlc_clear_di_map(mlc, 0);
317 		return -1;
318 	}
319 	hil_mlc_clear_di_map(mlc, mlc->ddi + 1);
320 
321 	return 0;
322 }
323 
324 static int hilse_inc_ddi(hil_mlc *mlc, int unused)
325 {
326 	BUG_ON(mlc->ddi >= 6);
327 	mlc->ddi++;
328 
329 	return 0;
330 }
331 
332 static int hilse_take_idd(hil_mlc *mlc, int unused)
333 {
334 	int i;
335 
336 	/* Help the state engine:
337 	 * Is this a real IDD response or just an echo?
338 	 *
339 	 * Real IDD response does not start with a command.
340 	 */
341 	if (mlc->ipacket[0] & HIL_PKT_CMD)
342 		goto bail;
343 
344 	/* Should have the command echoed further down. */
345 	for (i = 1; i < 16; i++) {
346 		if (((mlc->ipacket[i] & HIL_PKT_ADDR_MASK) ==
347 		     (mlc->ipacket[0] & HIL_PKT_ADDR_MASK)) &&
348 		    (mlc->ipacket[i] & HIL_PKT_CMD) &&
349 		    ((mlc->ipacket[i] & HIL_PKT_DATA_MASK) == HIL_CMD_IDD))
350 			break;
351 	}
352 	if (i > 15)
353 		goto bail;
354 
355 	/* And the rest of the packets should still be clear. */
356 	while (++i < 16)
357 		if (mlc->ipacket[i])
358 			break;
359 
360 	if (i < 16)
361 		goto bail;
362 
363 	for (i = 0; i < 16; i++)
364 		mlc->di_scratch.idd[i] =
365 			mlc->ipacket[i] & HIL_PKT_DATA_MASK;
366 
367 	/* Next step is to see if RSC supported */
368 	if (mlc->di_scratch.idd[1] & HIL_IDD_HEADER_RSC)
369 		return HILSEN_NEXT;
370 
371 	if (mlc->di_scratch.idd[1] & HIL_IDD_HEADER_EXD)
372 		return HILSEN_DOWN | 4;
373 
374 	return 0;
375 
376  bail:
377 	mlc->ddi--;
378 
379 	return -1; /* This should send us off to ACF */
380 }
381 
382 static int hilse_take_rsc(hil_mlc *mlc, int unused)
383 {
384 	int i;
385 
386 	for (i = 0; i < 16; i++)
387 		mlc->di_scratch.rsc[i] =
388 			mlc->ipacket[i] & HIL_PKT_DATA_MASK;
389 
390 	/* Next step is to see if EXD supported (IDD has already been read) */
391 	if (mlc->di_scratch.idd[1] & HIL_IDD_HEADER_EXD)
392 		return HILSEN_NEXT;
393 
394 	return 0;
395 }
396 
397 static int hilse_take_exd(hil_mlc *mlc, int unused)
398 {
399 	int i;
400 
401 	for (i = 0; i < 16; i++)
402 		mlc->di_scratch.exd[i] =
403 			mlc->ipacket[i] & HIL_PKT_DATA_MASK;
404 
405 	/* Next step is to see if RNM supported. */
406 	if (mlc->di_scratch.exd[0] & HIL_EXD_HEADER_RNM)
407 		return HILSEN_NEXT;
408 
409 	return 0;
410 }
411 
412 static int hilse_take_rnm(hil_mlc *mlc, int unused)
413 {
414 	int i;
415 
416 	for (i = 0; i < 16; i++)
417 		mlc->di_scratch.rnm[i] =
418 			mlc->ipacket[i] & HIL_PKT_DATA_MASK;
419 
420 	printk(KERN_INFO PREFIX "Device name gotten: %16s\n",
421 			mlc->di_scratch.rnm);
422 
423 	return 0;
424 }
425 
426 static int hilse_operate(hil_mlc *mlc, int repoll)
427 {
428 
429 	if (mlc->opercnt == 0)
430 		hil_mlcs_probe = 0;
431 	mlc->opercnt = 1;
432 
433 	hil_mlc_send_polls(mlc);
434 
435 	if (!hil_mlcs_probe)
436 		return 0;
437 	hil_mlcs_probe = 0;
438 	mlc->opercnt = 0;
439 	return 1;
440 }
441 
442 #define FUNC(funct, funct_arg, zero_rc, neg_rc, pos_rc) \
443 { HILSE_FUNC,		{ .func = funct }, funct_arg, zero_rc, neg_rc, pos_rc },
444 #define OUT(pack) \
445 { HILSE_OUT,		{ .packet = pack }, 0, HILSEN_NEXT, HILSEN_DOZE, 0 },
446 #define CTS \
447 { HILSE_CTS,		{ .packet = 0    }, 0, HILSEN_NEXT | HILSEN_SCHED | HILSEN_BREAK, HILSEN_DOZE, 0 },
448 #define EXPECT(comp, to, got, got_wrong, timed_out) \
449 { HILSE_EXPECT,		{ .packet = comp }, to, got, got_wrong, timed_out },
450 #define EXPECT_LAST(comp, to, got, got_wrong, timed_out) \
451 { HILSE_EXPECT_LAST,	{ .packet = comp }, to, got, got_wrong, timed_out },
452 #define EXPECT_DISC(comp, to, got, got_wrong, timed_out) \
453 { HILSE_EXPECT_DISC,	{ .packet = comp }, to, got, got_wrong, timed_out },
454 #define IN(to, got, got_error, timed_out) \
455 { HILSE_IN,		{ .packet = 0    }, to, got, got_error, timed_out },
456 #define OUT_DISC(pack) \
457 { HILSE_OUT_DISC,	{ .packet = pack }, 0, 0, 0, 0 },
458 #define OUT_LAST(pack) \
459 { HILSE_OUT_LAST,	{ .packet = pack }, 0, 0, 0, 0 },
460 
461 static const struct hilse_node hil_mlc_se[HILSEN_END] = {
462 
463 	/* 0  HILSEN_START */
464 	FUNC(hilse_init_lcv, 0,	HILSEN_NEXT,	HILSEN_SLEEP,	0)
465 
466 	/* 1  HILSEN_RESTART */
467 	FUNC(hilse_inc_lcv, 10,	HILSEN_NEXT,	HILSEN_START,  0)
468 	OUT(HIL_CTRL_ONLY)			/* Disable APE */
469 	CTS
470 
471 #define TEST_PACKET(x) \
472 (HIL_PKT_CMD | (x << HIL_PKT_ADDR_SHIFT) | x << 4 | x)
473 
474 	OUT(HIL_DO_ALTER_CTRL | HIL_CTRL_TEST | TEST_PACKET(0x5))
475 	EXPECT(HIL_ERR_INT | TEST_PACKET(0x5),
476 	       2000,		HILSEN_NEXT,	HILSEN_RESTART,	HILSEN_RESTART)
477 	OUT(HIL_DO_ALTER_CTRL | HIL_CTRL_TEST | TEST_PACKET(0xa))
478 	EXPECT(HIL_ERR_INT | TEST_PACKET(0xa),
479 	       2000,		HILSEN_NEXT,	HILSEN_RESTART,	HILSEN_RESTART)
480 	OUT(HIL_CTRL_ONLY | 0)			/* Disable test mode */
481 
482 	/* 9  HILSEN_DHR */
483 	FUNC(hilse_init_lcv, 0,	HILSEN_NEXT,	HILSEN_SLEEP,	0)
484 
485 	/* 10 HILSEN_DHR2 */
486 	FUNC(hilse_inc_lcv, 10,	HILSEN_NEXT,	HILSEN_START,	0)
487 	FUNC(hilse_set_ddi, -1,	HILSEN_NEXT,	0,		0)
488 	OUT(HIL_PKT_CMD | HIL_CMD_DHR)
489 	IN(300000,		HILSEN_DHR2,	HILSEN_DHR2,	HILSEN_NEXT)
490 
491 	/* 14 HILSEN_IFC */
492 	OUT(HIL_PKT_CMD | HIL_CMD_IFC)
493 	EXPECT(HIL_PKT_CMD | HIL_CMD_IFC | HIL_ERR_INT,
494 	       20000,		HILSEN_DISC,	HILSEN_DHR2,	HILSEN_NEXT )
495 
496 	/* If devices are there, they weren't in PUP or other loopback mode.
497 	 * We're more concerned at this point with restoring operation
498 	 * to devices than discovering new ones, so we try to salvage
499 	 * the loop configuration by closing off the loop.
500 	 */
501 
502 	/* 16 HILSEN_HEAL0 */
503 	FUNC(hilse_dec_ddi, 0,	HILSEN_NEXT,	HILSEN_ACF,	0)
504 	FUNC(hilse_inc_ddi, 0,	HILSEN_NEXT,	0,		0)
505 
506 	/* 18 HILSEN_HEAL */
507 	OUT_LAST(HIL_CMD_ELB)
508 	EXPECT_LAST(HIL_CMD_ELB | HIL_ERR_INT,
509 		    20000,	HILSEN_REPOLL,	HILSEN_DSR,	HILSEN_NEXT)
510 	FUNC(hilse_dec_ddi, 0,	HILSEN_HEAL,	HILSEN_NEXT,	0)
511 
512 	/* 21 HILSEN_ACF */
513 	FUNC(hilse_init_lcv, 0,	HILSEN_NEXT,	HILSEN_DOZE,	0)
514 
515 	/* 22 HILSEN_ACF2 */
516 	FUNC(hilse_inc_lcv, 10,	HILSEN_NEXT,	HILSEN_START,	0)
517 	OUT(HIL_PKT_CMD | HIL_CMD_ACF | 1)
518 	IN(20000,		HILSEN_NEXT,	HILSEN_DSR,	HILSEN_NEXT)
519 
520 	/* 25 HILSEN_DISC0 */
521 	OUT_DISC(HIL_PKT_CMD | HIL_CMD_ELB)
522 	EXPECT_DISC(HIL_PKT_CMD | HIL_CMD_ELB | HIL_ERR_INT,
523 	       20000,		HILSEN_NEXT,	HILSEN_DSR,	HILSEN_DSR)
524 
525 	/* Only enter here if response just received */
526 	/* 27 HILSEN_DISC */
527 	OUT_DISC(HIL_PKT_CMD | HIL_CMD_IDD)
528 	EXPECT_DISC(HIL_PKT_CMD | HIL_CMD_IDD | HIL_ERR_INT,
529 	       20000,		HILSEN_NEXT,	HILSEN_DSR,	HILSEN_START)
530 	FUNC(hilse_inc_ddi,  0,	HILSEN_NEXT,	HILSEN_START,	0)
531 	FUNC(hilse_take_idd, 0,	HILSEN_MATCH,	HILSEN_IFCACF,	HILSEN_FOLLOW)
532 	OUT_LAST(HIL_PKT_CMD | HIL_CMD_RSC)
533 	EXPECT_LAST(HIL_PKT_CMD | HIL_CMD_RSC | HIL_ERR_INT,
534 	       30000,		HILSEN_NEXT,	HILSEN_DSR,	HILSEN_DSR)
535 	FUNC(hilse_take_rsc, 0,	HILSEN_MATCH,	0,		HILSEN_FOLLOW)
536 	OUT_LAST(HIL_PKT_CMD | HIL_CMD_EXD)
537 	EXPECT_LAST(HIL_PKT_CMD | HIL_CMD_EXD | HIL_ERR_INT,
538 	       30000,		HILSEN_NEXT,	HILSEN_DSR,	HILSEN_DSR)
539 	FUNC(hilse_take_exd, 0,	HILSEN_MATCH,	0,		HILSEN_FOLLOW)
540 	OUT_LAST(HIL_PKT_CMD | HIL_CMD_RNM)
541 	EXPECT_LAST(HIL_PKT_CMD | HIL_CMD_RNM | HIL_ERR_INT,
542 	       30000,		HILSEN_NEXT,	HILSEN_DSR,	HILSEN_DSR)
543 	FUNC(hilse_take_rnm, 0, HILSEN_MATCH,	0,		0)
544 
545 	/* 40 HILSEN_MATCH */
546 	FUNC(hilse_match, 0,	HILSEN_NEXT,	HILSEN_NEXT,	/* TODO */ 0)
547 
548 	/* 41 HILSEN_OPERATE */
549 	OUT(HIL_PKT_CMD | HIL_CMD_POL)
550 	EXPECT(HIL_PKT_CMD | HIL_CMD_POL | HIL_ERR_INT,
551 	       20000,		HILSEN_NEXT,	HILSEN_DSR,	HILSEN_NEXT)
552 	FUNC(hilse_operate, 0,	HILSEN_OPERATE,	HILSEN_IFC,	HILSEN_NEXT)
553 
554 	/* 44 HILSEN_PROBE */
555 	OUT_LAST(HIL_PKT_CMD | HIL_CMD_EPT)
556 	IN(10000,		HILSEN_DISC,	HILSEN_DSR,	HILSEN_NEXT)
557 	OUT_DISC(HIL_PKT_CMD | HIL_CMD_ELB)
558 	IN(10000,		HILSEN_DISC,	HILSEN_DSR,	HILSEN_NEXT)
559 	OUT(HIL_PKT_CMD | HIL_CMD_ACF | 1)
560 	IN(10000,		HILSEN_DISC0,	HILSEN_DSR,	HILSEN_NEXT)
561 	OUT_LAST(HIL_PKT_CMD | HIL_CMD_ELB)
562 	IN(10000,		HILSEN_OPERATE,	HILSEN_DSR,	HILSEN_DSR)
563 
564 	/* 52 HILSEN_DSR */
565 	FUNC(hilse_set_ddi, -1,	HILSEN_NEXT,	0,		0)
566 	OUT(HIL_PKT_CMD | HIL_CMD_DSR)
567 	IN(20000,		HILSEN_DHR,	HILSEN_DHR,	HILSEN_IFC)
568 
569 	/* 55 HILSEN_REPOLL */
570 	OUT(HIL_PKT_CMD | HIL_CMD_RPL)
571 	EXPECT(HIL_PKT_CMD | HIL_CMD_RPL | HIL_ERR_INT,
572 	       20000,		HILSEN_NEXT,	HILSEN_DSR,	HILSEN_NEXT)
573 	FUNC(hilse_operate, 1,	HILSEN_OPERATE,	HILSEN_IFC,	HILSEN_PROBE)
574 
575 	/* 58 HILSEN_IFCACF */
576 	OUT(HIL_PKT_CMD | HIL_CMD_IFC)
577 	EXPECT(HIL_PKT_CMD | HIL_CMD_IFC | HIL_ERR_INT,
578 	       20000,		HILSEN_ACF2,	HILSEN_DHR2,	HILSEN_HEAL)
579 
580 	/* 60 HILSEN_END */
581 };
582 
583 static inline void hilse_setup_input(hil_mlc *mlc, const struct hilse_node *node)
584 {
585 
586 	switch (node->act) {
587 	case HILSE_EXPECT_DISC:
588 		mlc->imatch = node->object.packet;
589 		mlc->imatch |= ((mlc->ddi + 2) << HIL_PKT_ADDR_SHIFT);
590 		break;
591 	case HILSE_EXPECT_LAST:
592 		mlc->imatch = node->object.packet;
593 		mlc->imatch |= ((mlc->ddi + 1) << HIL_PKT_ADDR_SHIFT);
594 		break;
595 	case HILSE_EXPECT:
596 		mlc->imatch = node->object.packet;
597 		break;
598 	case HILSE_IN:
599 		mlc->imatch = 0;
600 		break;
601 	default:
602 		BUG();
603 	}
604 	mlc->istarted = 1;
605 	mlc->intimeout = usecs_to_jiffies(node->arg);
606 	mlc->instart = jiffies;
607 	mlc->icount = 15;
608 	memset(mlc->ipacket, 0, 16 * sizeof(hil_packet));
609 	BUG_ON(down_trylock(&mlc->isem));
610 }
611 
612 #ifdef HIL_MLC_DEBUG
613 static int doze;
614 static int seidx; /* For debug */
615 #endif
616 
617 static int hilse_donode(hil_mlc *mlc)
618 {
619 	const struct hilse_node *node;
620 	int nextidx = 0;
621 	int sched_long = 0;
622 	unsigned long flags;
623 
624 #ifdef HIL_MLC_DEBUG
625 	if (mlc->seidx && mlc->seidx != seidx &&
626 	    mlc->seidx != 41 && mlc->seidx != 42 && mlc->seidx != 43) {
627 		printk(KERN_DEBUG PREFIX "z%i \n {%i}", doze, mlc->seidx);
628 		doze = 0;
629 	}
630 
631 	seidx = mlc->seidx;
632 #endif
633 	node = hil_mlc_se + mlc->seidx;
634 
635 	switch (node->act) {
636 		int rc;
637 		hil_packet pack;
638 
639 	case HILSE_FUNC:
640 		BUG_ON(node->object.func == NULL);
641 		rc = node->object.func(mlc, node->arg);
642 		nextidx = (rc > 0) ? node->ugly :
643 			((rc < 0) ? node->bad : node->good);
644 		if (nextidx == HILSEN_FOLLOW)
645 			nextidx = rc;
646 		break;
647 
648 	case HILSE_EXPECT_LAST:
649 	case HILSE_EXPECT_DISC:
650 	case HILSE_EXPECT:
651 	case HILSE_IN:
652 		/* Already set up from previous HILSE_OUT_* */
653 		write_lock_irqsave(&mlc->lock, flags);
654 		rc = mlc->in(mlc, node->arg);
655 		if (rc == 2)  {
656 			nextidx = HILSEN_DOZE;
657 			sched_long = 1;
658 			write_unlock_irqrestore(&mlc->lock, flags);
659 			break;
660 		}
661 		if (rc == 1)
662 			nextidx = node->ugly;
663 		else if (rc == 0)
664 			nextidx = node->good;
665 		else
666 			nextidx = node->bad;
667 		mlc->istarted = 0;
668 		write_unlock_irqrestore(&mlc->lock, flags);
669 		break;
670 
671 	case HILSE_OUT_LAST:
672 		write_lock_irqsave(&mlc->lock, flags);
673 		pack = node->object.packet;
674 		pack |= ((mlc->ddi + 1) << HIL_PKT_ADDR_SHIFT);
675 		goto out;
676 
677 	case HILSE_OUT_DISC:
678 		write_lock_irqsave(&mlc->lock, flags);
679 		pack = node->object.packet;
680 		pack |= ((mlc->ddi + 2) << HIL_PKT_ADDR_SHIFT);
681 		goto out;
682 
683 	case HILSE_OUT:
684 		write_lock_irqsave(&mlc->lock, flags);
685 		pack = node->object.packet;
686 	out:
687 		if (!mlc->istarted) {
688 			/* Prepare to receive input */
689 			if ((node + 1)->act & HILSE_IN)
690 				hilse_setup_input(mlc, node + 1);
691 		}
692 
693 		write_unlock_irqrestore(&mlc->lock, flags);
694 
695 		if (down_trylock(&mlc->osem)) {
696 			nextidx = HILSEN_DOZE;
697 			break;
698 		}
699 		up(&mlc->osem);
700 
701 		write_lock_irqsave(&mlc->lock, flags);
702 		if (!mlc->ostarted) {
703 			mlc->ostarted = 1;
704 			mlc->opacket = pack;
705 			mlc->out(mlc);
706 			nextidx = HILSEN_DOZE;
707 			write_unlock_irqrestore(&mlc->lock, flags);
708 			break;
709 		}
710 		mlc->ostarted = 0;
711 		mlc->instart = jiffies;
712 		write_unlock_irqrestore(&mlc->lock, flags);
713 		nextidx = HILSEN_NEXT;
714 		break;
715 
716 	case HILSE_CTS:
717 		write_lock_irqsave(&mlc->lock, flags);
718 		nextidx = mlc->cts(mlc) ? node->bad : node->good;
719 		write_unlock_irqrestore(&mlc->lock, flags);
720 		break;
721 
722 	default:
723 		BUG();
724 	}
725 
726 #ifdef HIL_MLC_DEBUG
727 	if (nextidx == HILSEN_DOZE)
728 		doze++;
729 #endif
730 
731 	while (nextidx & HILSEN_SCHED) {
732 		unsigned long now = jiffies;
733 
734 		if (!sched_long)
735 			goto sched;
736 
737 		if (time_after(now, mlc->instart + mlc->intimeout))
738 			 goto sched;
739 		mod_timer(&hil_mlcs_kicker, mlc->instart + mlc->intimeout);
740 		break;
741 	sched:
742 		tasklet_schedule(&hil_mlcs_tasklet);
743 		break;
744 	}
745 
746 	if (nextidx & HILSEN_DOWN)
747 		mlc->seidx += nextidx & HILSEN_MASK;
748 	else if (nextidx & HILSEN_UP)
749 		mlc->seidx -= nextidx & HILSEN_MASK;
750 	else
751 		mlc->seidx = nextidx & HILSEN_MASK;
752 
753 	if (nextidx & HILSEN_BREAK)
754 		return 1;
755 
756 	return 0;
757 }
758 
759 /******************** tasklet context functions **************************/
760 static void hil_mlcs_process(unsigned long unused)
761 {
762 	struct list_head *tmp;
763 
764 	read_lock(&hil_mlcs_lock);
765 	list_for_each(tmp, &hil_mlcs) {
766 		struct hil_mlc *mlc = list_entry(tmp, hil_mlc, list);
767 		while (hilse_donode(mlc) == 0) {
768 #ifdef HIL_MLC_DEBUG
769 			if (mlc->seidx != 41 &&
770 			    mlc->seidx != 42 &&
771 			    mlc->seidx != 43)
772 				printk(KERN_DEBUG PREFIX " + ");
773 #endif
774 		}
775 	}
776 	read_unlock(&hil_mlcs_lock);
777 }
778 
779 /************************* Keepalive timer task *********************/
780 
781 static void hil_mlcs_timer(struct timer_list *unused)
782 {
783 	hil_mlcs_probe = 1;
784 	tasklet_schedule(&hil_mlcs_tasklet);
785 	/* Re-insert the periodic task. */
786 	if (!timer_pending(&hil_mlcs_kicker))
787 		mod_timer(&hil_mlcs_kicker, jiffies + HZ);
788 }
789 
790 /******************** user/kernel context functions **********************/
791 
792 static int hil_mlc_serio_write(struct serio *serio, unsigned char c)
793 {
794 	struct hil_mlc_serio_map *map;
795 	struct hil_mlc *mlc;
796 	struct serio_driver *drv;
797 	uint8_t *idx, *last;
798 
799 	map = serio->port_data;
800 	BUG_ON(map == NULL);
801 
802 	mlc = map->mlc;
803 	BUG_ON(mlc == NULL);
804 
805 	mlc->serio_opacket[map->didx] |=
806 		((hil_packet)c) << (8 * (3 - mlc->serio_oidx[map->didx]));
807 
808 	if (mlc->serio_oidx[map->didx] >= 3) {
809 		/* for now only commands */
810 		if (!(mlc->serio_opacket[map->didx] & HIL_PKT_CMD))
811 			return -EIO;
812 		switch (mlc->serio_opacket[map->didx] & HIL_PKT_DATA_MASK) {
813 		case HIL_CMD_IDD:
814 			idx = mlc->di[map->didx].idd;
815 			goto emu;
816 		case HIL_CMD_RSC:
817 			idx = mlc->di[map->didx].rsc;
818 			goto emu;
819 		case HIL_CMD_EXD:
820 			idx = mlc->di[map->didx].exd;
821 			goto emu;
822 		case HIL_CMD_RNM:
823 			idx = mlc->di[map->didx].rnm;
824 			goto emu;
825 		default:
826 			break;
827 		}
828 		mlc->serio_oidx[map->didx] = 0;
829 		mlc->serio_opacket[map->didx] = 0;
830 	}
831 
832 	mlc->serio_oidx[map->didx]++;
833 	return -EIO;
834  emu:
835 	drv = serio->drv;
836 	BUG_ON(drv == NULL);
837 
838 	last = idx + 15;
839 	while ((last != idx) && (*last == 0))
840 		last--;
841 
842 	while (idx != last) {
843 		drv->interrupt(serio, 0, 0);
844 		drv->interrupt(serio, HIL_ERR_INT >> 16, 0);
845 		drv->interrupt(serio, 0, 0);
846 		drv->interrupt(serio, *idx, 0);
847 		idx++;
848 	}
849 	drv->interrupt(serio, 0, 0);
850 	drv->interrupt(serio, HIL_ERR_INT >> 16, 0);
851 	drv->interrupt(serio, HIL_PKT_CMD >> 8, 0);
852 	drv->interrupt(serio, *idx, 0);
853 
854 	mlc->serio_oidx[map->didx] = 0;
855 	mlc->serio_opacket[map->didx] = 0;
856 
857 	return 0;
858 }
859 
860 static int hil_mlc_serio_open(struct serio *serio)
861 {
862 	struct hil_mlc_serio_map *map;
863 	struct hil_mlc *mlc;
864 
865 	if (serio_get_drvdata(serio) != NULL)
866 		return -EBUSY;
867 
868 	map = serio->port_data;
869 	BUG_ON(map == NULL);
870 
871 	mlc = map->mlc;
872 	BUG_ON(mlc == NULL);
873 
874 	return 0;
875 }
876 
877 static void hil_mlc_serio_close(struct serio *serio)
878 {
879 	struct hil_mlc_serio_map *map;
880 	struct hil_mlc *mlc;
881 
882 	map = serio->port_data;
883 	BUG_ON(map == NULL);
884 
885 	mlc = map->mlc;
886 	BUG_ON(mlc == NULL);
887 
888 	serio_set_drvdata(serio, NULL);
889 	serio->drv = NULL;
890 	/* TODO wake up interruptable */
891 }
892 
893 static const struct serio_device_id hil_mlc_serio_id = {
894 	.type = SERIO_HIL_MLC,
895 	.proto = SERIO_HIL,
896 	.extra = SERIO_ANY,
897 	.id = SERIO_ANY,
898 };
899 
900 int hil_mlc_register(hil_mlc *mlc)
901 {
902 	int i;
903 	unsigned long flags;
904 
905 	BUG_ON(mlc == NULL);
906 
907 	mlc->istarted = 0;
908 	mlc->ostarted = 0;
909 
910 	rwlock_init(&mlc->lock);
911 	sema_init(&mlc->osem, 1);
912 
913 	sema_init(&mlc->isem, 1);
914 	mlc->icount = -1;
915 	mlc->imatch = 0;
916 
917 	mlc->opercnt = 0;
918 
919 	sema_init(&(mlc->csem), 0);
920 
921 	hil_mlc_clear_di_scratch(mlc);
922 	hil_mlc_clear_di_map(mlc, 0);
923 	for (i = 0; i < HIL_MLC_DEVMEM; i++) {
924 		struct serio *mlc_serio;
925 		hil_mlc_copy_di_scratch(mlc, i);
926 		mlc_serio = kzalloc(sizeof(*mlc_serio), GFP_KERNEL);
927 		mlc->serio[i] = mlc_serio;
928 		if (!mlc->serio[i]) {
929 			for (; i >= 0; i--)
930 				kfree(mlc->serio[i]);
931 			return -ENOMEM;
932 		}
933 		snprintf(mlc_serio->name, sizeof(mlc_serio->name)-1, "HIL_SERIO%d", i);
934 		snprintf(mlc_serio->phys, sizeof(mlc_serio->phys)-1, "HIL%d", i);
935 		mlc_serio->id			= hil_mlc_serio_id;
936 		mlc_serio->id.id		= i; /* HIL port no. */
937 		mlc_serio->write		= hil_mlc_serio_write;
938 		mlc_serio->open			= hil_mlc_serio_open;
939 		mlc_serio->close		= hil_mlc_serio_close;
940 		mlc_serio->port_data		= &(mlc->serio_map[i]);
941 		mlc->serio_map[i].mlc		= mlc;
942 		mlc->serio_map[i].didx		= i;
943 		mlc->serio_map[i].di_revmap	= -1;
944 		mlc->serio_opacket[i]		= 0;
945 		mlc->serio_oidx[i]		= 0;
946 		serio_register_port(mlc_serio);
947 	}
948 
949 	mlc->tasklet = &hil_mlcs_tasklet;
950 
951 	write_lock_irqsave(&hil_mlcs_lock, flags);
952 	list_add_tail(&mlc->list, &hil_mlcs);
953 	mlc->seidx = HILSEN_START;
954 	write_unlock_irqrestore(&hil_mlcs_lock, flags);
955 
956 	tasklet_schedule(&hil_mlcs_tasklet);
957 	return 0;
958 }
959 
960 int hil_mlc_unregister(hil_mlc *mlc)
961 {
962 	struct list_head *tmp;
963 	unsigned long flags;
964 	int i;
965 
966 	BUG_ON(mlc == NULL);
967 
968 	write_lock_irqsave(&hil_mlcs_lock, flags);
969 	list_for_each(tmp, &hil_mlcs)
970 		if (list_entry(tmp, hil_mlc, list) == mlc)
971 			goto found;
972 
973 	/* not found in list */
974 	write_unlock_irqrestore(&hil_mlcs_lock, flags);
975 	tasklet_schedule(&hil_mlcs_tasklet);
976 	return -ENODEV;
977 
978  found:
979 	list_del(tmp);
980 	write_unlock_irqrestore(&hil_mlcs_lock, flags);
981 
982 	for (i = 0; i < HIL_MLC_DEVMEM; i++) {
983 		serio_unregister_port(mlc->serio[i]);
984 		mlc->serio[i] = NULL;
985 	}
986 
987 	tasklet_schedule(&hil_mlcs_tasklet);
988 	return 0;
989 }
990 
991 /**************************** Module interface *************************/
992 
993 static int __init hil_mlc_init(void)
994 {
995 	timer_setup(&hil_mlcs_kicker, &hil_mlcs_timer, 0);
996 	mod_timer(&hil_mlcs_kicker, jiffies + HZ);
997 
998 	tasklet_enable(&hil_mlcs_tasklet);
999 
1000 	return 0;
1001 }
1002 
1003 static void __exit hil_mlc_exit(void)
1004 {
1005 	del_timer_sync(&hil_mlcs_kicker);
1006 	tasklet_kill(&hil_mlcs_tasklet);
1007 }
1008 
1009 module_init(hil_mlc_init);
1010 module_exit(hil_mlc_exit);
1011