xref: /dragonfly/sys/dev/smbus/atmel_mxt/atmel_mxt.c (revision ed183f8c)
1 /*
2  * Copyright (c) 2014 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
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  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 /*
35  * ATMEL_MXT - Atmel MXT touchscreen driver
36  *
37  *	PRELIMINARY DRIVER PRELIMINARY DRIVER PRELIMINARY DRIVERE
38  *
39  * (everything is pretty much hardwired and we assume the device is already
40  *  operational, which it appears to be.  ONLY TESTED ON ACER C720).
41  *
42  * This driver attaches to Acer TouchScreen MXT chipsets and currently
43  * emulates the ELO touchscreen serial protocol "elographics" for X:
44  *
45  *	Section "InputDevice"
46  *		Identifier  "TouchScreen0"
47  *		Driver      "elographics"
48  *		Option      "Device" "/dev/atmel1-4a"
49  *	EndSection
50  *
51  * The MXT chipsets typically attach on haswell chromebooks on one of the I2C
52  * busses at address 0x4A.  On my Acer C720 it attaches to the ig4 driver's
53  * I2C bus #1 at 0x4A.  kldload ig4; kldload atmel_mxt.
54  *
55  * The kernel driver and test code is written from scratch, but some code has
56  * been snarfed (in separate files) from linux development as referenced
57  * here:
58  *
59  * www.atmel.com/products/touchsolutions/touchscreens/unlimited_touch.aspx
60  * git://github.com/atmel-maxtouch/obp-utils.git
61  *
62  * The linux driver was also consulted, but not used.  Note that the linux
63  * driver appears to be GPL'd but uses code from obp-utils.git on github
64  * which is (c)Copyright by Atmel and uses more of a BSD-like license.  The
65  * obp-* source files contain the snarfed code and include this license.
66  *
67  * The ELO touchscreen serial protocol uses 10-byte fixed-length packets:
68  *
69  *	Byte 0:	    ELO_SYNC_BYTE ('U')
70  *	Byte 1-8:   Packet data
71  *	Byte 9:	    checksum of bytes 0 to 8
72  *
73  * Our interface reads and writes only whole packets and does not do any
74  * buffer stitching.  It is compatible with Xorg.
75  *
76  * Control Commands sent from Userland (only an Ack packet is returned)
77  *
78  *	Byte 0:	    ELO_SYNC_BYTE ('U')
79  *	Byte 1:	    ELO_MODE ('m')
80  *	Byte 2:	    Flags
81  *	    0x80 -
82  *	    0x40 Tracking mode
83  *	    0x20 -
84  *	    0x10 -
85  *	    0x08 Scaling mode
86  *	    0x04 Untouch mode
87  *	    0x02 Streaming mode
88  *	    0x01 Touch mode
89  *
90  *	Byte 0:	    ELO_SYNC_BYTE ('U')
91  *	Byte 1:	    ELO_REPORT ('r')
92  *
93  * Query Command sent from Userland: (expect response packet and Ack packet)
94  *
95  *	Byte 0:	    ELO_SYNC_BYTE ('U')		Request ID
96  *	Byte 1:	    ELO_ID ('i')
97  *
98  *	Byte 0:	    ELO_SYNC_BYTE ('U')`	Request Owner
99  *	Byte 1:	    ELO_OWNER ('o')
100  *
101  * Streaming packets sent from the driver to userland
102  *
103  *	Byte 0:	    ELO_SYNC_BYTE ('U')
104  *	Byte 1:	    ELO_TOUCH ('T')
105  *	Byte 2:	    Packet type
106  *	  Bit 2 : Pen Up	(Release)	0x04
107  *	  Bit 1 : Position	(Stream)	0x02
108  *	  Bit 0 : Pen Down	(Press)		0x01
109  *	Byte 3:	    X coordinate lsb
110  *	Byte 4:	    X coordinate msb
111  *	Byte 5:	    Y coordinate lsb
112  *	Byte 6:	    Y coordinate msb
113  *	Byte 7:	    Z coordinate lsb
114  *	Byte 8:	    Z coordinate msb
115  *
116  * Responses to commands: (one or two packets returned)
117  *
118  *	Byte 0:	    ELO_SYNC_BYTE ('U')		(if in response to query)
119  *	Byte 1:	    toupper(command_byte)	(control commands have no
120  *	Byte 2-8:   ... depends ....		 response)
121  *
122  *	Byte 0:	    ELO_SYNC_BYTE ('U')		(unconditional ack)
123  *	Byte 1:	    'A'ck
124  *	Byte 2-8:   ... depends ....
125  *
126  * NOTE!  For the most part we ignore commands other than doing the handwaving
127  *	  to send a dummied-up response and ack as assumed by the X driver.
128  *	  Also, the read() and write() support only reads and writes whole
129  *	  packets.  There is NO byte-partial buffering.  The X driver appears
130  *	  to be compatible with these restrictions.
131  *
132  * figure out the bootstrapping and commands.
133  *
134  * Unable to locate any datasheet for the device.
135  *
136  *				    FEATURES
137  *
138  * Currently no features.  Only one finger is supported by this attachment
139  * for now and I haven't written any de-jitter and finger-transfer code.
140  * This is good enough for moving and resizing windows (given big enough
141  * widgets), and hitting browser buttons and hotlinks.
142  *
143  * Currently no scrolling control or other features.  We would need to
144  * basically implement either the linux general input even infrastructure
145  * which is a LOT of code, or a mouse emulator to handle scrolling emulation.
146  */
147 #include <sys/kernel.h>
148 #include <sys/param.h>
149 #include <sys/systm.h>
150 #include <sys/device.h>
151 #include <sys/module.h>
152 #include <sys/bus.h>
153 #include <sys/conf.h>
154 #include <sys/uio.h>
155 #include <sys/fcntl.h>
156 #include <sys/vnode.h>
157 #include <sys/sysctl.h>
158 #include <sys/event.h>
159 #include <sys/devfs.h>
160 
161 #include <bus/smbus/smbconf.h>
162 #include <bus/smbus/smbus.h>
163 #include "atmel_mxt.h"
164 
165 #include "smbus_if.h"
166 
167 struct elopacket {
168 	uint8_t	sync;
169 	uint8_t	cmd;
170 	uint8_t	byte2;
171 	uint8_t	byte3;
172 	uint8_t	byte4;
173 	uint8_t	byte5;
174 	uint8_t	byte6;
175 	uint8_t	byte7;
176 	uint8_t	byte8;
177 	uint8_t	csum;
178 } __packed;
179 
180 typedef struct elopacket elopacket_t;
181 
182 typedef struct atmel_track {
183 	uint16_t x;
184 	uint16_t y;
185 	uint16_t pressure;
186 	int	status;
187 	int	report;		/* what we have to report */
188 } atmel_track_t;
189 
190 #define ATMEL_TRACK_RELEASED		0
191 #define ATMEL_TRACK_PRESSED		1
192 
193 #define ATMEL_REPORT_PRESS	0x0001
194 #define ATMEL_REPORT_MOVE	0x0002
195 #define ATMEL_REPORT_RELEASE	0x0004
196 
197 #define ATMEL_MAXTRACK		10
198 
199 struct atmel_mxt_softc {
200 	device_t dev;
201 	int	count;			/* >0 if device opened */
202 	int	unit;
203 	int	addr;
204 	cdev_t	devnode;
205 	struct kqinfo kqinfo;
206 	struct lock lk;
207 
208 	int	poll_flags;
209 	thread_t poll_td;
210 
211 	/*
212 	 * Hardware state
213 	 */
214 	struct mxt_rollup	core;
215 	struct mxt_object	*msgprocobj;
216 	struct mxt_object	*cmdprocobj;
217 
218 	/*
219 	 * Capabilities
220 	 */
221 	short	cap_resx;
222 	short	cap_resy;
223 
224 	/*
225 	 * Emulation
226 	 */
227 	atmel_track_t track[ATMEL_MAXTRACK];
228 	int	tracking;
229 	int	track_fingers;
230 
231 	elopacket_t pend_rep;		/* pending reply to command */
232 	int	pend_ack;		/* pending reply mode */
233 
234 	int	last_active_tick;
235 	int	last_calibrate_tick;
236 	int	data_signal;		/* something ready to read */
237 	int	blocked;		/* someone is blocking */
238 	int	reporting_mode;
239 	int	sample_rate;		/* samples/sec */
240 	int	poll_ticks;
241 };
242 
243 typedef struct atmel_mxt_softc atmel_mxt_softc_t;
244 
245 #define ATMEL_POLL_SHUTDOWN	0x0001
246 
247 #define PEND_ACK_NONE		0	/* no reply to command pending */
248 #define PEND_ACK_RESPOND	1	/* reply w/response and ack */
249 #define PEND_ACK_ACK		2	/* reply w/ack only */
250 
251 #define REPORT_NONE		0x0000
252 #define REPORT_ALL		0x0001
253 
254 /*
255  * Async debug variable commands are executed by the poller and will
256  * auto-clear.
257  */
258 static int atmel_mxt_idle_freq = 1;
259 SYSCTL_INT(_debug, OID_AUTO, atmel_mxt_idle_freq, CTLFLAG_RW,
260 		&atmel_mxt_idle_freq, 0, "");
261 static int atmel_mxt_slow_freq = 20;
262 SYSCTL_INT(_debug, OID_AUTO, atmel_mxt_slow_freq, CTLFLAG_RW,
263 		&atmel_mxt_slow_freq, 0, "");
264 static int atmel_mxt_norm_freq = 100;
265 SYSCTL_INT(_debug, OID_AUTO, atmel_mxt_norm_freq, CTLFLAG_RW,
266 		&atmel_mxt_norm_freq, 0, "");
267 static int atmel_mxt_minpressure = 16;
268 SYSCTL_INT(_debug, OID_AUTO, atmel_mxt_minpressure, CTLFLAG_RW,
269 		&atmel_mxt_minpressure, 0, "");
270 static int atmel_mxt_reset = 0;
271 SYSCTL_INT(_debug, OID_AUTO, atmel_mxt_reset, CTLFLAG_RW,
272 		&atmel_mxt_reset, 0, "");
273 
274 /*
275  * Run a calibration command every N seconds only when idle.  0 to disable.
276  * Default every 30 seconds.
277  */
278 static int atmel_mxt_autocalibrate = 30;
279 SYSCTL_INT(_debug, OID_AUTO, atmel_mxt_autocalibrate, CTLFLAG_RW,
280 		&atmel_mxt_autocalibrate, 0, "");
281 
282 /*
283  * run a calibration on module startup.
284  */
285 static int atmel_mxt_debug = 0;
286 SYSCTL_INT(_debug, OID_AUTO, atmel_mxt_debug, CTLFLAG_RW,
287 		&atmel_mxt_debug, 0, "");
288 
289 static void atmel_mxt_poll_thread(void *arg);
290 static void atmel_find_active_state(atmel_mxt_softc_t *sc);
291 static int atmel_mxt_raw_input(atmel_mxt_softc_t *sc, mxt_message_t *msg);
292 static struct mxt_object *mxt_findobject(struct mxt_rollup *core, int type);
293 static int mxt_read_reg(atmel_mxt_softc_t *sc, uint16_t reg,
294 			void *rbuf, int bytes);
295 static int mxt_write_reg_buf(atmel_mxt_softc_t *sc, uint16_t reg,
296 			void *xbuf, int bytes);
297 static int mxt_write_reg(atmel_mxt_softc_t *sc, uint16_t reg, uint8_t val);
298 static int mxt_read_object(atmel_mxt_softc_t *sc, struct mxt_object *obj,
299 			void *rbuf, int rbytes);
300 static int mxt_write_object_off(atmel_mxt_softc_t *sc, struct mxt_object *obj,
301 			int offset, uint8_t val);
302 static void atmel_reset_device(atmel_mxt_softc_t *sc);
303 
304 static
305 const char *
306 msgflagsstr(uint8_t flags)
307 {
308 	static char buf[9];
309 
310 	buf[0] = (flags & MXT_MSGF_DETECT) ? 'D' : '.';
311 	buf[1] = (flags & MXT_MSGF_PRESS) ? 'P' : '.';
312 	buf[2] = (flags & MXT_MSGF_RELEASE) ? 'R' : '.';
313 	buf[3] = (flags & MXT_MSGF_MOVE) ? 'M' : '.';
314 	buf[4] = (flags & MXT_MSGF_VECTOR) ? 'V' : '.';
315 	buf[5] = (flags & MXT_MSGF_AMP) ? 'A' : '.';
316 	buf[6] = (flags & MXT_MSGF_SUPPRESS) ? 'S' : '.';
317 	buf[7] = (flags & MXT_MSGF_UNGRIP) ? 'U' : '.';
318 
319 	return buf;
320 }
321 
322 static
323 void
324 atmel_mxt_lock(atmel_mxt_softc_t *sc)
325 {
326 	lockmgr(&sc->lk, LK_EXCLUSIVE);
327 }
328 
329 static
330 void
331 atmel_mxt_unlock(atmel_mxt_softc_t *sc)
332 {
333 	lockmgr(&sc->lk, LK_RELEASE);
334 }
335 
336 /*
337  * Notify if possible receive data ready.  Must be called
338  * without the lock held to avoid deadlocking in kqueue.
339  */
340 static
341 void
342 atmel_mxt_notify(atmel_mxt_softc_t *sc)
343 {
344 	if (sc->data_signal) {
345 		KNOTE(&sc->kqinfo.ki_note, 0);
346 		atmel_mxt_lock(sc);
347 		if (sc->blocked) {
348 			sc->blocked = 0;
349 			wakeup(&sc->blocked);
350 		}
351 		atmel_mxt_unlock(sc);
352 	}
353 }
354 
355 /*
356  * Initialize the device
357  */
358 static
359 int
360 init_device(atmel_mxt_softc_t *sc, int probe)
361 {
362 	int blksize;
363 	int totsize;
364 	uint32_t crc;
365 
366 	if (mxt_read_reg(sc, 0, &sc->core.info, sizeof(sc->core.info))) {
367 		device_printf(sc->dev, "init_device read-reg failed\n");
368 		return ENXIO;
369 	}
370 	sc->core.nobjs = sc->core.info.num_objects;
371 	if (!probe) {
372 		device_printf(sc->dev,
373 			      "%d configuration objects\n",
374 			      sc->core.info.num_objects);
375 	}
376 	if (sc->core.nobjs < 0 || sc->core.nobjs > 1024) {
377 		device_printf(sc->dev,
378 			      "init_device nobjs (%d) out of bounds\n",
379 			      sc->core.nobjs);
380 		return ENXIO;
381 	}
382 	blksize = sizeof(sc->core.info) +
383 		  sc->core.nobjs * sizeof(struct mxt_object);
384 	totsize = blksize + sizeof(struct mxt_raw_crc);
385 
386 	sc->core.buf = kmalloc(totsize, M_DEVBUF, M_WAITOK | M_ZERO);
387 	if (mxt_read_reg(sc, 0, sc->core.buf, totsize)) {
388 		device_printf(sc->dev,
389 			      "init_device cannot read configuration space\n");
390 		goto done;
391 	}
392 	kprintf("COREBUF %p %d\n", sc->core.buf, blksize);
393 	crc = obp_convert_crc((void *)((uint8_t *)sc->core.buf + blksize));
394 	if (obp_crc24(sc->core.buf, blksize) != crc) {
395 		device_printf(sc->dev,
396 			      "init_device: configuration space "
397 			      "crc mismatch %08x/%08x\n",
398 			      crc, obp_crc24(sc->core.buf, blksize));
399 		/*goto done;*/
400 	}
401 	{
402 		int i;
403 
404 		kprintf("info:   ");
405 		for (i = 0; i < sizeof(sc->core.info); ++i)
406 			kprintf(" %02x", sc->core.buf[i]);
407 		kprintf("\nconfig: ");
408 		while (i < blksize) {
409 			kprintf(" %02x", sc->core.buf[i]);
410 			++i;
411 		}
412 		kprintf("\n");
413 	}
414 	sc->core.objs = (void *)((uint8_t *)sc->core.buf +
415 				 sizeof(sc->core.info));
416 	sc->msgprocobj = mxt_findobject(&sc->core, MXT_GEN_MESSAGEPROCESSOR);
417 	sc->cmdprocobj = mxt_findobject(&sc->core, MXT_GEN_COMMANDPROCESSOR);
418 	if (sc->msgprocobj == NULL) {
419 		device_printf(sc->dev,
420 			      "init_device: cannot find msgproc config\n");
421 		goto done;
422 	}
423 
424 done:
425 	if (sc->msgprocobj == NULL) {
426 		if (sc->core.buf) {
427 			kfree(sc->core.buf, M_DEVBUF);
428 			sc->core.buf = NULL;
429 		}
430 		return ENXIO;
431 	} else {
432 		if (probe) {
433 			kfree(sc->core.buf, M_DEVBUF);
434 			sc->core.buf = NULL;
435 		} else {
436 			atmel_reset_device(sc);
437 		}
438 		return 0;
439 	}
440 }
441 
442 /*
443  * Device infrastructure
444  */
445 #define ATMEL_SOFTC(unit) \
446 	((atmel_mxt_softc_t *)devclass_get_softc(atmel_mxt_devclass, (unit)))
447 
448 static void atmel_mxt_identify(driver_t *driver, device_t parent);
449 static int atmel_mxt_probe(device_t);
450 static int atmel_mxt_attach(device_t);
451 static int atmel_mxt_detach(device_t);
452 
453 static devclass_t atmel_mxt_devclass;
454 
455 static device_method_t atmel_mxt_methods[] = {
456 	/* device interface */
457 	DEVMETHOD(device_identify,	atmel_mxt_identify),
458 	DEVMETHOD(device_probe,		atmel_mxt_probe),
459 	DEVMETHOD(device_attach,	atmel_mxt_attach),
460 	DEVMETHOD(device_detach,	atmel_mxt_detach),
461 
462 #if 0
463 	/* smbus interface */
464 	DEVMETHOD(smbus_intr,		smbus_generic_intr),
465 #endif
466 
467 	DEVMETHOD_END
468 };
469 
470 static driver_t atmel_mxt_driver = {
471 	"atmel_mxt",
472 	atmel_mxt_methods,
473 	sizeof(atmel_mxt_softc_t),
474 };
475 
476 static	d_open_t	atmel_mxtopen;
477 static	d_close_t	atmel_mxtclose;
478 static	d_ioctl_t	atmel_mxtioctl;
479 static	d_read_t	atmel_mxtread;
480 static	d_write_t	atmel_mxtwrite;
481 static	d_kqfilter_t	atmel_mxtkqfilter;
482 
483 static struct dev_ops atmel_mxt_ops = {
484 	{ "atmel_mxt", 0, 0 },
485 	.d_open =	atmel_mxtopen,
486 	.d_close =	atmel_mxtclose,
487 	.d_ioctl =	atmel_mxtioctl,
488 	.d_read =	atmel_mxtread,
489 	.d_write =	atmel_mxtwrite,
490 	.d_kqfilter =	atmel_mxtkqfilter,
491 };
492 
493 static void
494 atmel_mxt_identify(driver_t *driver, device_t parent)
495 {
496 	if (device_find_child(parent, "atmel_mxt", -1) == NULL)
497 		BUS_ADD_CHILD(parent, parent, 0, "atmel_mxt", -1);
498 }
499 
500 static int
501 atmel_mxt_probe(device_t dev)
502 {
503 	atmel_mxt_softc_t sc;
504 	int error;
505 
506 	bzero(&sc, sizeof(sc));
507 	sc.dev = dev;
508 	sc.unit = device_get_unit(dev);
509 
510 	/*
511 	 * Only match against specific addresses to avoid blowing up
512 	 * other I2C devices (?).  At least for now.
513 	 *
514 	 * 0x400 (from smbus) - means specific device address probe,
515 	 *			rather than generic.
516 	 *
517 	 * 0x4A - cypress trackpad on the acer c720.
518 	 */
519 	if ((sc.unit & 0x04FF) != (0x0400 | 0x04A))
520 		return ENXIO;
521 	sc.addr = sc.unit & 0x3FF;
522 	error = init_device(&sc, 1);
523 	if (error)
524 		return ENXIO;
525 
526 	device_set_desc(dev, "Atmel MXT TouchScreen");
527 
528 	return (BUS_PROBE_VENDOR);
529 }
530 
531 static int
532 atmel_mxt_attach(device_t dev)
533 {
534 	atmel_mxt_softc_t *sc;
535 
536 	sc = (atmel_mxt_softc_t *)device_get_softc(dev);
537 	if (!sc)
538 		return ENOMEM;
539 
540 	bzero(sc, sizeof(*sc));
541 
542 	lockinit(&sc->lk, "atmel_mxt", 0, 0);
543 	sc->reporting_mode = 1;
544 
545 	sc->dev = dev;
546 	sc->unit = device_get_unit(dev);
547 	if ((sc->unit & 0x04FF) != (0x0400 | 0x04A))
548 		return ENXIO;
549 	sc->addr = sc->unit & 0x3FF;
550 	sc->last_active_tick = ticks;
551 	sc->last_calibrate_tick = ticks - atmel_mxt_autocalibrate * hz;
552 
553 	if (init_device(sc, 0))
554 		return ENXIO;
555 
556 	if (sc->unit & 0x0400) {
557 		sc->devnode = make_dev(&atmel_mxt_ops, sc->unit,
558 				UID_ROOT, GID_WHEEL, 0600,
559 				"atmel%d-%02x",
560 				sc->unit >> 11, sc->unit & 1023);
561 	} else {
562 		sc->devnode = make_dev(&atmel_mxt_ops, sc->unit,
563 				UID_ROOT, GID_WHEEL, 0600, "atmel%d", sc->unit);
564 	}
565 	device_printf(dev, "atmel mxt touchscreen driver attached\n");
566 	/* device_printf(dev, "...."); */
567 
568 	/*
569 	 * Start the polling thread.
570 	 */
571 	lwkt_create(atmel_mxt_poll_thread, sc,
572 		    &sc->poll_td, NULL, 0, -1, "atmel_mxt-poll");
573 
574 	return (0);
575 }
576 
577 static int
578 atmel_mxt_detach(device_t dev)
579 {
580 	atmel_mxt_softc_t *sc;
581 
582 	sc = (atmel_mxt_softc_t *)device_get_softc(dev);
583 
584 	/*
585 	 * Cleanup our poller thread
586 	 */
587 	atomic_set_int(&sc->poll_flags, ATMEL_POLL_SHUTDOWN);
588 	while (sc->poll_td) {
589 		wakeup(&sc->poll_flags);
590 		tsleep(&sc->poll_td, 0, "atmel_mxtdet", hz);
591 	}
592 
593 	if (sc->devnode)
594 		dev_ops_remove_minor(&atmel_mxt_ops, device_get_unit(dev));
595 	if (sc->devnode)
596 		devfs_assume_knotes(sc->devnode, &sc->kqinfo);
597 	if (sc->core.buf) {
598 		kfree(sc->core.buf, M_DEVBUF);
599 		sc->core.buf = NULL;
600 	}
601 	sc->msgprocobj = NULL;
602 	sc->cmdprocobj = NULL;
603 
604 	return (0);
605 }
606 
607 /*
608  * USER DEVICE I/O FUNCTIONS
609  */
610 static int
611 atmel_mxtopen (struct dev_open_args *ap)
612 {
613 	cdev_t dev = ap->a_head.a_dev;
614 	atmel_mxt_softc_t *sc = ATMEL_SOFTC(minor(dev));
615 
616 	if (sc == NULL)
617 		return (ENXIO);
618 
619 	if (sc->count != 0)
620 		return (EBUSY);
621 
622 	sc->count++;
623 
624 	return (0);
625 }
626 
627 static int
628 atmel_mxtclose(struct dev_close_args *ap)
629 {
630 	cdev_t dev = ap->a_head.a_dev;
631 	atmel_mxt_softc_t *sc = ATMEL_SOFTC(minor(dev));
632 
633 	if (sc == NULL)
634 		return (ENXIO);
635 
636 	if (sc->count == 0) {
637 		/* This is not supposed to happen. */
638 		return (0);
639 	}
640 
641 	if (sc->count-- == 0) {
642 		sc->reporting_mode = 0;
643 	}
644 
645 	return (0);
646 }
647 
648 static int
649 atmel_mxtread(struct dev_read_args *ap)
650 {
651 	cdev_t dev = ap->a_head.a_dev;
652 	atmel_mxt_softc_t *sc = ATMEL_SOFTC(minor(dev));
653 	int error;
654 	struct uio *uio = ap->a_uio;
655 	int ioflag = ap->a_ioflag;
656 	size_t n;
657 	elopacket_t pkt;
658 	atmel_track_t *track;
659 
660 	/*
661 	 * Load next ready event, block if necessary.
662 	 */
663 	atmel_mxt_lock(sc);
664 	for (;;) {
665 		error = 0;
666 
667 		switch(sc->pend_ack) {
668 		case PEND_ACK_NONE:
669 			if (sc->tracking && sc->track[sc->tracking].report) {
670 				/*
671 				 * Report ready
672 				 */
673 				track = &sc->track[sc->tracking];
674 				bzero(&pkt, sizeof(pkt));
675 				pkt.cmd = 'T';
676 				if (track->report & ATMEL_REPORT_PRESS) {
677 					pkt.byte2 |= 0x01;
678 					track->report &= ~ATMEL_REPORT_PRESS;
679 				} else if (track->report & ATMEL_REPORT_MOVE) {
680 					pkt.byte2 |= 0x02;
681 					track->report &= ~ATMEL_REPORT_MOVE;
682 				} else if (track->report &
683 					   ATMEL_REPORT_RELEASE) {
684 					pkt.byte2 |= 0x04;
685 					track->report &= ~ATMEL_REPORT_RELEASE;
686 				}
687 				pkt.byte3 = track->x & 0xFF;
688 				pkt.byte4 = track->x >> 8;
689 				pkt.byte5 = track->y & 0xFF;
690 				pkt.byte6 = track->y >> 8;
691 				pkt.byte7 = track->pressure & 0xFF;
692 				pkt.byte8 = track->pressure >> 8;
693 			} else if (ioflag & IO_NDELAY) {
694 				/*
695 				 * Non-blocking, nothing ready
696 				 */
697 				error = EWOULDBLOCK;
698 			} else {
699 				/*
700 				 * Blocking, nothing ready
701 				 */
702 				sc->data_signal = 0;
703 				sc->blocked = 1;
704 				error = lksleep(&sc->blocked, &sc->lk,
705 						PCATCH, "atmelw", 0);
706 				if (error == 0)
707 					continue;
708 			}
709 			break;
710 		case PEND_ACK_RESPOND:
711 			pkt = sc->pend_rep;
712 			sc->pend_ack = PEND_ACK_ACK;
713 			break;
714 		case PEND_ACK_ACK:
715 			bzero(&pkt, sizeof(pkt));
716 			pkt.cmd = 'A';
717 			sc->pend_ack = PEND_ACK_NONE;
718 			break;
719 		}
720 		atmel_find_active_state(sc);
721 		break;
722 	}
723 	atmel_mxt_unlock(sc);
724 
725 	/*
726 	 * If no error we can return the event loaded into pkt.
727 	 */
728 	if (error == 0) {
729 		uint8_t csum = 0xAA;
730 		int i;
731 
732 		pkt.sync = 'U';
733 		for (i = 0; i < sizeof(pkt) - 1; ++i)
734 			csum += ((uint8_t *)&pkt)[i];
735 		pkt.csum = csum;
736 		n = uio->uio_resid;
737 		if (n > sizeof(pkt))
738 			n = sizeof(pkt);
739 		error = uiomove((void *)&pkt, n, uio);
740 	}
741 
742 	return error;
743 }
744 
745 static int
746 atmel_mxtwrite(struct dev_write_args *ap)
747 {
748 	cdev_t dev = ap->a_head.a_dev;
749 	atmel_mxt_softc_t *sc = ATMEL_SOFTC(minor(dev));
750 	struct uio *uio = ap->a_uio;
751 	elopacket_t pkt;
752 	int error;
753 	size_t n;
754 
755 	error = 0;
756 
757 	while (uio->uio_resid) {
758 		bzero(&pkt, sizeof(pkt));
759 		n = uio->uio_resid;
760 		if (n > sizeof(pkt))
761 			n = sizeof(pkt);
762 		error = uiomove((void *)&pkt, n, uio);
763 		if (error)
764 			break;
765 		atmel_mxt_lock(sc);
766 		switch(pkt.cmd) {
767 		case 'i':
768 			/*
769 			 * ELO_ID request id
770 			 */
771 			bzero(&sc->pend_rep, sizeof(sc->pend_rep));
772 			sc->pend_rep.cmd = 'I';
773 			sc->pend_ack = PEND_ACK_RESPOND;
774 			break;
775 		case 'o':
776 			/*
777 			 * ELO_OWNER request owner
778 			 */
779 			bzero(&sc->pend_rep, sizeof(sc->pend_rep));
780 			sc->pend_rep.cmd = 'O';
781 			sc->pend_ack = PEND_ACK_RESPOND;
782 			break;
783 		case 'm':
784 			/*
785 			 * ELO_MODE control packet
786 			 */
787 			sc->pend_ack = PEND_ACK_ACK;
788 			break;
789 		case 'r':
790 			/*
791 			 * ELO_REPORT control packet
792 			 */
793 			sc->pend_ack = PEND_ACK_ACK;
794 			break;
795 		}
796 		atmel_mxt_unlock(sc);
797 	}
798 	return error;
799 }
800 
801 static void atmel_mxt_filt_detach(struct knote *);
802 static int atmel_mxt_filt(struct knote *, long);
803 
804 static struct filterops atmel_mxt_filtops =
805         { FILTEROP_ISFD, NULL, atmel_mxt_filt_detach, atmel_mxt_filt };
806 
807 static int
808 atmel_mxtkqfilter(struct dev_kqfilter_args *ap)
809 {
810 	cdev_t dev = ap->a_head.a_dev;
811 	atmel_mxt_softc_t *sc = ATMEL_SOFTC(minor(dev));
812 	struct knote *kn = ap->a_kn;
813 	struct klist *klist;
814 
815 	switch(kn->kn_filter) {
816 	case EVFILT_READ:
817 		kn->kn_fop = &atmel_mxt_filtops;
818 		kn->kn_hook = (void *)sc;
819 		ap->a_result = 0;
820 		break;
821 	default:
822 		ap->a_result = EOPNOTSUPP;
823 		return (0);
824 	}
825 	klist = &sc->kqinfo.ki_note;
826 	knote_insert(klist, kn);
827 
828 	return (0);
829 }
830 
831 static void
832 atmel_mxt_filt_detach(struct knote *kn)
833 {
834 	atmel_mxt_softc_t *sc = (atmel_mxt_softc_t *)kn->kn_hook;
835 	struct klist *klist;
836 
837 	klist = &sc->kqinfo.ki_note;
838 	knote_remove(klist, kn);
839 }
840 
841 static int
842 atmel_mxt_filt(struct knote *kn, long hint)
843 {
844 	atmel_mxt_softc_t *sc = (atmel_mxt_softc_t *)kn->kn_hook;
845 	int ready;
846 
847 	atmel_mxt_lock(sc);
848 	if (sc->data_signal)
849 		ready = 1;
850 	else
851 		ready = 0;
852 	atmel_mxt_unlock(sc);
853 
854 	return (ready);
855 }
856 
857 static int
858 atmel_mxtioctl(struct dev_ioctl_args *ap)
859 {
860 	cdev_t dev = ap->a_head.a_dev;
861 	device_t bus;		/* smbbus */
862 	/*struct atmel_mxtcmd *s = (struct atmel_mxtcmd *)ap->a_data;*/
863 	void *s = NULL;
864 	atmel_mxt_softc_t *sc = ATMEL_SOFTC(minor(dev));
865 	int error;
866 
867 	if (sc == NULL)
868 		return (ENXIO);
869 	if (s == NULL)
870 		return (EINVAL);
871 
872 	/*
873 	 * NOTE: smbus_*() functions automatically recurse the parent to
874 	 *	 get to the actual device driver.
875 	 */
876 	bus = device_get_parent(sc->dev);	/* smbus */
877 
878 	/* Allocate the bus. */
879 	if ((error = smbus_request_bus(bus, sc->dev,
880 			(ap->a_fflag & O_NONBLOCK) ?
881 			SMB_DONTWAIT : (SMB_WAIT | SMB_INTR))))
882 		return (error);
883 
884 	switch (ap->a_cmd) {
885 	default:
886 #if 0
887 		error = inputev_ioctl(&sc->iev, ap->a_cmd, ap->a_data);
888 #endif
889 		error = ENOTTY;
890 		break;
891 	}
892 
893 	smbus_release_bus(bus, sc->dev);
894 
895 	return (error);
896 }
897 
898 /*
899  * MAJOR SUPPORT FUNCTIONS
900  */
901 static
902 void
903 atmel_mxt_poll_thread(void *arg)
904 {
905 	atmel_mxt_softc_t *sc = arg;
906 	int error;
907 	int freq = atmel_mxt_norm_freq;
908 	int isidle = 0;
909 
910 	while ((sc->poll_flags & ATMEL_POLL_SHUTDOWN) == 0) {
911 		if (sc->msgprocobj)
912 			error = 0;
913 		else
914 			error = ENXIO;
915 		if (error == 0) {
916 			mxt_message_t msg;
917 
918 			error = mxt_read_object(sc, sc->msgprocobj,
919 					    &msg, sizeof(msg));
920 			if (error == 0)
921 				isidle = atmel_mxt_raw_input(sc, &msg);
922 			else
923 				isidle = 1;
924 		}
925 
926 		/*
927 		 * don't let the last_active_tick or last_calibrate_tick
928 		 * delta calculation overflow.
929 		 */
930 		if ((ticks - sc->last_active_tick) > 1000 * hz)
931 			sc->last_active_tick = ticks - 1000 * hz;
932 		if ((ticks - sc->last_calibrate_tick) > 1000 * hz)
933 			sc->last_calibrate_tick = ticks - 1000 * hz;
934 
935 		/*
936 		 * Reset if requested
937 		 */
938 		if (atmel_mxt_reset) {
939 			atmel_mxt_reset = 0;
940 			atmel_reset_device(sc);
941 		}
942 
943 		/*
944 		 * Automatically calibrate when the touchpad has been
945 		 * idle atmel_mxt_autocalibrate seconds, and recalibrate
946 		 * on the same interval while it remains idle.
947 		 *
948 		 * If we don't do this the touchscreen can get really out
949 		 * of whack over time and basically stop functioning properly.
950 		 * It's unclear why the device does not do this automatically.
951 		 *
952 		 * Response occurs in the message stream (which we just
953 		 * ignore).
954 		 */
955 		if (sc->cmdprocobj && atmel_mxt_autocalibrate &&
956 		    ((ticks - sc->last_calibrate_tick) >
957 		     atmel_mxt_autocalibrate * hz) &&
958 		    ((ticks - sc->last_active_tick) >
959 		     atmel_mxt_autocalibrate * hz)) {
960 			sc->last_calibrate_tick = ticks;
961 			mxt_write_object_off(sc, sc->cmdprocobj,
962 					 MXT_CMDPROC_CALIBRATE_OFF, 1);
963 		}
964 		tsleep(&sc->poll_flags, 0, "atmpol", (hz + freq - 1) / freq);
965 		++sc->poll_ticks;
966 		if (sc->count == 0)
967 			freq = atmel_mxt_idle_freq;
968 		else if (isidle)
969 			freq = atmel_mxt_slow_freq;
970 		else
971 			freq = atmel_mxt_norm_freq;
972 	}
973 	sc->poll_td = NULL;
974 	wakeup(&sc->poll_td);
975 }
976 
977 static
978 void
979 atmel_reset_device(atmel_mxt_softc_t *sc)
980 {
981 	int dummy;
982 	mxt_write_object_off(sc, sc->cmdprocobj, MXT_CMDPROC_RESET_OFF, 1);
983 	tsleep(&dummy, 0, "atmel_reset", hz * 2);
984 }
985 
986 /*
987  * Calculate currently active state, if any
988  */
989 static
990 void
991 atmel_find_active_state(atmel_mxt_softc_t *sc)
992 {
993 	atmel_track_t *track;
994 	int i;
995 
996 	track = &sc->track[sc->tracking];
997 	if (track->report == 0) {
998 		for (i = 0; i < ATMEL_MAXTRACK; ++i) {
999 			track = &sc->track[i];
1000 			if (track->report) {
1001 				sc->tracking = i;
1002 				break;
1003 			}
1004 		}
1005 	}
1006 	if (track->report == 0 && sc->pend_ack == PEND_ACK_NONE) {
1007 		sc->data_signal = 0;
1008 	} else {
1009 		sc->data_signal = 1;
1010 	}
1011 }
1012 
1013 /*
1014  * Return non-zero if we are idle
1015  */
1016 static
1017 int
1018 atmel_mxt_raw_input(atmel_mxt_softc_t *sc, mxt_message_t *msg)
1019 {
1020 	atmel_track_t *track;
1021 	int donotify = 0;
1022 
1023 	if (atmel_mxt_debug) {
1024 		kprintf("track=%02x f=%s x=%-4d y=%-4d p=%d amp=%d\n",
1025 			msg->any.reportid,
1026 			msgflagsstr(msg->touch.flags),
1027 			(msg->touch.pos[0] << 4) |
1028 				((msg->touch.pos[2] >> 4) & 0x0F),
1029 			(msg->touch.pos[1] << 4) |
1030 				((msg->touch.pos[2]) & 0x0F),
1031 			msg->touch.area,
1032 			msg->touch.amplitude);
1033 	}
1034 	atmel_mxt_lock(sc);
1035 
1036 	/*
1037 	 * If message buffer is empty and no fingers are currently pressed
1038 	 * return idle, else we are not idle.
1039 	 */
1040 	if (msg->any.reportid == 0xFF)
1041 		goto done;
1042 
1043 	/*
1044 	 * Process message buffer.  For now ignore any messages with
1045 	 * reportids that we do not understand.
1046 	 *
1047 	 * note: reportid==1  typicallk acknowledges calibrations (?)
1048 	 */
1049 	if (msg->any.reportid < 3 || msg->any.reportid >= ATMEL_MAXTRACK)
1050 		goto done;
1051 
1052 	sc->last_active_tick = ticks;
1053 
1054 	track = &sc->track[msg->any.reportid];
1055 	track->x = (msg->touch.pos[0] << 4) |
1056 		   ((msg->touch.pos[2] >> 4) & 0x0F);
1057 	track->y = (msg->touch.pos[1] << 4) |
1058 		   (msg->touch.pos[2] & 0x0F);
1059 	track->pressure = msg->touch.amplitude;
1060 
1061 	track->x = track->x * 3000 / 1361;
1062 	track->y = track->y * 3000 / 3064;
1063 
1064 	if (msg->touch.flags & MXT_MSGF_DETECT) {
1065 		track->status = ATMEL_TRACK_PRESSED;
1066 		if (msg->touch.flags & MXT_MSGF_PRESS) {
1067 			track->report |= ATMEL_REPORT_PRESS;
1068 		}
1069 		if (msg->touch.flags & MXT_MSGF_MOVE) {
1070 			track->report |= ATMEL_REPORT_MOVE;
1071 		}
1072 	} else {
1073 		track->status = ATMEL_TRACK_RELEASED;
1074 		track->report |= ATMEL_REPORT_RELEASE;
1075 	}
1076 	atmel_find_active_state(sc);
1077 	donotify = 1;
1078 done:
1079 	atmel_mxt_unlock(sc);
1080 	if (donotify)
1081 		atmel_mxt_notify(sc);
1082 	if (sc->track_fingers)
1083 		return 0;
1084 	else
1085 		return 1;
1086 }
1087 
1088 /*
1089  * Support functions
1090  */
1091 static
1092 struct mxt_object *
1093 mxt_findobject(struct mxt_rollup *core, int type)
1094 {
1095 	int i;
1096 
1097 	for (i = 0; i < core->nobjs; ++i) {
1098 		if (core->objs[i].type == type)
1099 			return(&core->objs[i]);
1100 	}
1101 	return NULL;
1102 }
1103 
1104 static int
1105 mxt_read_reg(atmel_mxt_softc_t *sc, uint16_t reg, void *rbuf, int bytes)
1106 {
1107 	uint8_t wreg[2];
1108 	device_t bus;
1109 	int error;
1110 	int rbytes;
1111 
1112 	wreg[0] = reg & 255;
1113 	wreg[1] = reg >> 8;
1114 
1115 	bus = device_get_parent(sc->dev);
1116 	if ((error = smbus_request_bus(bus, sc->dev, SMB_WAIT | SMB_INTR)) != 0)
1117 		return error;
1118 	error = smbus_trans(bus, sc->addr, 0,
1119 			    SMB_TRANS_NOCNT |
1120 			    SMB_TRANS_NOCMD |
1121 			    SMB_TRANS_7BIT,
1122 			    wreg, 2,
1123 			    rbuf, bytes, &rbytes);
1124 	smbus_release_bus(bus, sc->dev);
1125 
1126 	if (bytes != rbytes) {
1127 		device_printf(sc->dev,
1128 			      "smbus_trans reg %d short read %d/%d\n",
1129 			      reg, bytes, rbytes);
1130 		error = EINVAL;
1131 	}
1132 
1133 	return error;
1134 }
1135 
1136 static int
1137 mxt_write_reg_buf(atmel_mxt_softc_t *sc, uint16_t reg, void *xbuf, int bytes)
1138 {
1139 	uint8_t wbuf[256];
1140 	device_t bus;
1141 	int error;
1142 
1143 	KKASSERT(bytes < sizeof(wbuf) - 2);
1144 	wbuf[0] = reg & 255;
1145 	wbuf[1] = reg >> 8;
1146 	bcopy(xbuf, wbuf + 2, bytes);
1147 
1148 	bus = device_get_parent(sc->dev);
1149 	if ((error = smbus_request_bus(bus, sc->dev, SMB_WAIT | SMB_INTR)) != 0)
1150 		return error;
1151 	error = smbus_trans(bus, sc->addr, 0,
1152 			    SMB_TRANS_NOCNT |
1153 			    SMB_TRANS_NOCMD |
1154 			    SMB_TRANS_7BIT,
1155 			    wbuf, bytes + 2,
1156 			    NULL, 0, NULL);
1157 	smbus_release_bus(bus, sc->dev);
1158 	return error;
1159 }
1160 
1161 static int
1162 mxt_write_reg(atmel_mxt_softc_t *sc, uint16_t reg, uint8_t val)
1163 {
1164 	return mxt_write_reg_buf(sc, reg, &val, 1);
1165 }
1166 
1167 static int
1168 mxt_read_object(atmel_mxt_softc_t *sc, struct mxt_object *obj,
1169 	        void *rbuf, int rbytes)
1170 {
1171 	uint16_t reg = obj->start_pos_lsb + (obj->start_pos_msb << 8);
1172 	int bytes = obj->size_minus_one + 1;
1173 
1174 	if (bytes > rbytes)
1175 		bytes = rbytes;
1176 	return mxt_read_reg(sc, reg, rbuf, bytes);
1177 }
1178 
1179 static int
1180 mxt_write_object_off(atmel_mxt_softc_t *sc, struct mxt_object *obj,
1181 		 int offset, uint8_t val)
1182 {
1183 	uint16_t reg = obj->start_pos_lsb + (obj->start_pos_msb << 8);
1184 
1185 	reg += offset;
1186 	return mxt_write_reg(sc, reg, val);
1187 }
1188 
1189 DRIVER_MODULE(atmel_mxt, smbus, atmel_mxt_driver, atmel_mxt_devclass,
1190 	      NULL, NULL);
1191 MODULE_DEPEND(atmel_mxt, smbus, SMBUS_MINVER, SMBUS_PREFVER, SMBUS_MAXVER);
1192 MODULE_VERSION(atmel_mxt, 1);
1193