xref: /freebsd/sys/arm/ti/ti_adc.c (revision 349cc55c9796c4596a5b9904cd3281af295f878f)
1 /*-
2  * Copyright 2014 Luiz Otavio O Souza <loos@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_evdev.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 
36 #include <sys/conf.h>
37 #include <sys/kernel.h>
38 #include <sys/limits.h>
39 #include <sys/lock.h>
40 #include <sys/module.h>
41 #include <sys/mutex.h>
42 #include <sys/condvar.h>
43 #include <sys/resource.h>
44 #include <sys/rman.h>
45 #include <sys/sysctl.h>
46 #include <sys/selinfo.h>
47 #include <sys/poll.h>
48 #include <sys/uio.h>
49 
50 #include <machine/bus.h>
51 
52 #include <dev/ofw/openfirm.h>
53 #include <dev/ofw/ofw_bus.h>
54 #include <dev/ofw/ofw_bus_subr.h>
55 
56 #ifdef EVDEV_SUPPORT
57 #include <dev/evdev/input.h>
58 #include <dev/evdev/evdev.h>
59 #endif
60 
61 #include <arm/ti/ti_sysc.h>
62 #include <arm/ti/ti_adcreg.h>
63 #include <arm/ti/ti_adcvar.h>
64 
65 #undef	DEBUG_TSC
66 
67 #define	DEFAULT_CHARGE_DELAY	0x400
68 #define	STEPDLY_OPEN		0x98
69 
70 #define	ORDER_XP	0
71 #define	ORDER_XN	1
72 #define	ORDER_YP	2
73 #define	ORDER_YN	3
74 
75 /* Define our 8 steps, one for each input channel. */
76 static struct ti_adc_input ti_adc_inputs[TI_ADC_NPINS] = {
77 	{ .stepconfig = ADC_STEPCFG(1), .stepdelay = ADC_STEPDLY(1) },
78 	{ .stepconfig = ADC_STEPCFG(2), .stepdelay = ADC_STEPDLY(2) },
79 	{ .stepconfig = ADC_STEPCFG(3), .stepdelay = ADC_STEPDLY(3) },
80 	{ .stepconfig = ADC_STEPCFG(4), .stepdelay = ADC_STEPDLY(4) },
81 	{ .stepconfig = ADC_STEPCFG(5), .stepdelay = ADC_STEPDLY(5) },
82 	{ .stepconfig = ADC_STEPCFG(6), .stepdelay = ADC_STEPDLY(6) },
83 	{ .stepconfig = ADC_STEPCFG(7), .stepdelay = ADC_STEPDLY(7) },
84 	{ .stepconfig = ADC_STEPCFG(8), .stepdelay = ADC_STEPDLY(8) },
85 };
86 
87 static int ti_adc_samples[5] = { 0, 2, 4, 8, 16 };
88 
89 static int ti_adc_detach(device_t dev);
90 
91 #ifdef EVDEV_SUPPORT
92 static void
93 ti_adc_ev_report(struct ti_adc_softc *sc)
94 {
95 
96 	evdev_push_event(sc->sc_evdev, EV_ABS, ABS_X, sc->sc_x);
97 	evdev_push_event(sc->sc_evdev, EV_ABS, ABS_Y, sc->sc_y);
98 	evdev_push_event(sc->sc_evdev, EV_KEY, BTN_TOUCH, sc->sc_pen_down);
99 	evdev_sync(sc->sc_evdev);
100 }
101 #endif /* EVDEV */
102 
103 static void
104 ti_adc_enable(struct ti_adc_softc *sc)
105 {
106 	uint32_t reg;
107 
108 	TI_ADC_LOCK_ASSERT(sc);
109 
110 	if (sc->sc_last_state == 1)
111 		return;
112 
113 	/* Enable the FIFO0 threshold and the end of sequence interrupt. */
114 	ADC_WRITE4(sc, ADC_IRQENABLE_SET,
115 	    ADC_IRQ_FIFO0_THRES | ADC_IRQ_FIFO1_THRES | ADC_IRQ_END_OF_SEQ);
116 
117 	reg = ADC_CTRL_STEP_WP | ADC_CTRL_STEP_ID;
118 	if (sc->sc_tsc_wires > 0) {
119 		reg |= ADC_CTRL_TSC_ENABLE;
120 		switch (sc->sc_tsc_wires) {
121 		case 4:
122 			reg |= ADC_CTRL_TSC_4WIRE;
123 			break;
124 		case 5:
125 			reg |= ADC_CTRL_TSC_5WIRE;
126 			break;
127 		case 8:
128 			reg |= ADC_CTRL_TSC_8WIRE;
129 			break;
130 		default:
131 			break;
132 		}
133 	}
134 	reg |= ADC_CTRL_ENABLE;
135 	/* Enable the ADC.  Run thru enabled steps, start the conversions. */
136 	ADC_WRITE4(sc, ADC_CTRL, reg);
137 
138 	sc->sc_last_state = 1;
139 }
140 
141 static void
142 ti_adc_disable(struct ti_adc_softc *sc)
143 {
144 	int count;
145 
146 	TI_ADC_LOCK_ASSERT(sc);
147 
148 	if (sc->sc_last_state == 0)
149 		return;
150 
151 	/* Disable all the enabled steps. */
152 	ADC_WRITE4(sc, ADC_STEPENABLE, 0);
153 
154 	/* Disable the ADC. */
155 	ADC_WRITE4(sc, ADC_CTRL, ADC_READ4(sc, ADC_CTRL) & ~ADC_CTRL_ENABLE);
156 
157 	/* Disable the FIFO0 threshold and the end of sequence interrupt. */
158 	ADC_WRITE4(sc, ADC_IRQENABLE_CLR,
159 	    ADC_IRQ_FIFO0_THRES | ADC_IRQ_FIFO1_THRES | ADC_IRQ_END_OF_SEQ);
160 
161 	/* ACK any pending interrupt. */
162 	ADC_WRITE4(sc, ADC_IRQSTATUS, ADC_READ4(sc, ADC_IRQSTATUS));
163 
164 	/* Drain the FIFO data. */
165 	count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
166 	while (count > 0) {
167 		(void)ADC_READ4(sc, ADC_FIFO0DATA);
168 		count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
169 	}
170 
171 	count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
172 	while (count > 0) {
173 		(void)ADC_READ4(sc, ADC_FIFO1DATA);
174 		count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
175 	}
176 
177 	sc->sc_last_state = 0;
178 }
179 
180 static int
181 ti_adc_setup(struct ti_adc_softc *sc)
182 {
183 	int ain, i;
184 	uint32_t enabled;
185 
186 	TI_ADC_LOCK_ASSERT(sc);
187 
188 	/* Check for enabled inputs. */
189 	enabled = sc->sc_tsc_enabled;
190 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
191 		ain = sc->sc_adc_channels[i];
192 		if (ti_adc_inputs[ain].enable)
193 			enabled |= (1U << (ain + 1));
194 	}
195 
196 	/* Set the ADC global status. */
197 	if (enabled != 0) {
198 		ti_adc_enable(sc);
199 		/* Update the enabled steps. */
200 		if (enabled != ADC_READ4(sc, ADC_STEPENABLE))
201 			ADC_WRITE4(sc, ADC_STEPENABLE, enabled);
202 	} else
203 		ti_adc_disable(sc);
204 
205 	return (0);
206 }
207 
208 static void
209 ti_adc_input_setup(struct ti_adc_softc *sc, int32_t ain)
210 {
211 	struct ti_adc_input *input;
212 	uint32_t reg, val;
213 
214 	TI_ADC_LOCK_ASSERT(sc);
215 
216 	input = &ti_adc_inputs[ain];
217 	reg = input->stepconfig;
218 	val = ADC_READ4(sc, reg);
219 
220 	/* Set single ended operation. */
221 	val &= ~ADC_STEP_DIFF_CNTRL;
222 
223 	/* Set the negative voltage reference. */
224 	val &= ~ADC_STEP_RFM_MSK;
225 
226 	/* Set the positive voltage reference. */
227 	val &= ~ADC_STEP_RFP_MSK;
228 
229 	/* Set the samples average. */
230 	val &= ~ADC_STEP_AVG_MSK;
231 	val |= input->samples << ADC_STEP_AVG_SHIFT;
232 
233 	/* Select the desired input. */
234 	val &= ~ADC_STEP_INP_MSK;
235 	val |= ain << ADC_STEP_INP_SHIFT;
236 
237 	/* Set the ADC to one-shot mode. */
238 	val &= ~ADC_STEP_MODE_MSK;
239 
240 	ADC_WRITE4(sc, reg, val);
241 }
242 
243 static void
244 ti_adc_reset(struct ti_adc_softc *sc)
245 {
246 	int ain, i;
247 
248 	TI_ADC_LOCK_ASSERT(sc);
249 
250 	/* Disable all the inputs. */
251 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
252 		ain = sc->sc_adc_channels[i];
253 		ti_adc_inputs[ain].enable = 0;
254 	}
255 }
256 
257 static int
258 ti_adc_clockdiv_proc(SYSCTL_HANDLER_ARGS)
259 {
260 	int error, reg;
261 	struct ti_adc_softc *sc;
262 
263 	sc = (struct ti_adc_softc *)arg1;
264 
265 	TI_ADC_LOCK(sc);
266 	reg = (int)ADC_READ4(sc, ADC_CLKDIV) + 1;
267 	TI_ADC_UNLOCK(sc);
268 
269 	error = sysctl_handle_int(oidp, &reg, sizeof(reg), req);
270 	if (error != 0 || req->newptr == NULL)
271 		return (error);
272 
273 	/*
274 	 * The actual written value is the prescaler setting - 1.
275 	 * Enforce a minimum value of 10 (i.e. 9) which limits the maximum
276 	 * ADC clock to ~2.4Mhz (CLK_M_OSC / 10).
277 	 */
278 	reg--;
279 	if (reg < 9)
280 		reg = 9;
281 	if (reg > USHRT_MAX)
282 		reg = USHRT_MAX;
283 
284 	TI_ADC_LOCK(sc);
285 	/* Disable the ADC. */
286 	ti_adc_disable(sc);
287 	/* Update the ADC prescaler setting. */
288 	ADC_WRITE4(sc, ADC_CLKDIV, reg);
289 	/* Enable the ADC again. */
290 	ti_adc_setup(sc);
291 	TI_ADC_UNLOCK(sc);
292 
293 	return (0);
294 }
295 
296 static int
297 ti_adc_enable_proc(SYSCTL_HANDLER_ARGS)
298 {
299 	int error;
300 	int32_t enable;
301 	struct ti_adc_softc *sc;
302 	struct ti_adc_input *input;
303 
304 	input = (struct ti_adc_input *)arg1;
305 	sc = input->sc;
306 
307 	enable = input->enable;
308 	error = sysctl_handle_int(oidp, &enable, sizeof(enable),
309 	    req);
310 	if (error != 0 || req->newptr == NULL)
311 		return (error);
312 
313 	if (enable)
314 		enable = 1;
315 
316 	TI_ADC_LOCK(sc);
317 	/* Setup the ADC as needed. */
318 	if (input->enable != enable) {
319 		input->enable = enable;
320 		ti_adc_setup(sc);
321 		if (input->enable == 0)
322 			input->value = 0;
323 	}
324 	TI_ADC_UNLOCK(sc);
325 
326 	return (0);
327 }
328 
329 static int
330 ti_adc_open_delay_proc(SYSCTL_HANDLER_ARGS)
331 {
332 	int error, reg;
333 	struct ti_adc_softc *sc;
334 	struct ti_adc_input *input;
335 
336 	input = (struct ti_adc_input *)arg1;
337 	sc = input->sc;
338 
339 	TI_ADC_LOCK(sc);
340 	reg = (int)ADC_READ4(sc, input->stepdelay) & ADC_STEP_OPEN_DELAY;
341 	TI_ADC_UNLOCK(sc);
342 
343 	error = sysctl_handle_int(oidp, &reg, sizeof(reg), req);
344 	if (error != 0 || req->newptr == NULL)
345 		return (error);
346 
347 	if (reg < 0)
348 		reg = 0;
349 
350 	TI_ADC_LOCK(sc);
351 	ADC_WRITE4(sc, input->stepdelay, reg & ADC_STEP_OPEN_DELAY);
352 	TI_ADC_UNLOCK(sc);
353 
354 	return (0);
355 }
356 
357 static int
358 ti_adc_samples_avg_proc(SYSCTL_HANDLER_ARGS)
359 {
360 	int error, samples, i;
361 	struct ti_adc_softc *sc;
362 	struct ti_adc_input *input;
363 
364 	input = (struct ti_adc_input *)arg1;
365 	sc = input->sc;
366 
367 	if (input->samples > nitems(ti_adc_samples))
368 		input->samples = nitems(ti_adc_samples);
369 	samples = ti_adc_samples[input->samples];
370 
371 	error = sysctl_handle_int(oidp, &samples, 0, req);
372 	if (error != 0 || req->newptr == NULL)
373 		return (error);
374 
375 	TI_ADC_LOCK(sc);
376 	if (samples != ti_adc_samples[input->samples]) {
377 		input->samples = 0;
378 		for (i = 0; i < nitems(ti_adc_samples); i++)
379 			if (samples >= ti_adc_samples[i])
380 				input->samples = i;
381 		ti_adc_input_setup(sc, input->input);
382 	}
383 	TI_ADC_UNLOCK(sc);
384 
385 	return (error);
386 }
387 
388 static void
389 ti_adc_read_data(struct ti_adc_softc *sc)
390 {
391 	int count, ain;
392 	struct ti_adc_input *input;
393 	uint32_t data;
394 
395 	TI_ADC_LOCK_ASSERT(sc);
396 
397 	/* Read the available data. */
398 	count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
399 	while (count > 0) {
400 		data = ADC_READ4(sc, ADC_FIFO0DATA);
401 		ain = (data & ADC_FIFO_STEP_ID_MSK) >> ADC_FIFO_STEP_ID_SHIFT;
402 		input = &ti_adc_inputs[ain];
403 		if (input->enable == 0)
404 			input->value = 0;
405 		else
406 			input->value = (int32_t)(data & ADC_FIFO_DATA_MSK);
407 		count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
408 	}
409 }
410 
411 static int
412 cmp_values(const void *a, const void *b)
413 {
414 	const uint32_t *v1, *v2;
415 	v1 = a;
416 	v2 = b;
417 	if (*v1 < *v2)
418 		return -1;
419 	if (*v1 > *v2)
420 		return 1;
421 
422 	return (0);
423 }
424 
425 static void
426 ti_adc_tsc_read_data(struct ti_adc_softc *sc)
427 {
428 	int count;
429 	uint32_t data[16];
430 	uint32_t x, y;
431 	int i, start, end;
432 
433 	TI_ADC_LOCK_ASSERT(sc);
434 
435 	/* Read the available data. */
436 	count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
437 	if (count == 0)
438 		return;
439 
440 	i = 0;
441 	while (count > 0) {
442 		data[i++] = ADC_READ4(sc, ADC_FIFO1DATA) & ADC_FIFO_DATA_MSK;
443 		count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
444 	}
445 
446 	if (sc->sc_coord_readouts > 3) {
447 		start = 1;
448 		end = sc->sc_coord_readouts - 1;
449 		qsort(data, sc->sc_coord_readouts,
450 			sizeof(data[0]), &cmp_values);
451 		qsort(&data[sc->sc_coord_readouts + 2],
452 			sc->sc_coord_readouts,
453 			sizeof(data[0]), &cmp_values);
454 	}
455 	else {
456 		start = 0;
457 		end = sc->sc_coord_readouts;
458 	}
459 
460 	x = y = 0;
461 	for (i = start; i < end; i++)
462 		y += data[i];
463 	y /= (end - start);
464 
465 	for (i = sc->sc_coord_readouts + 2 + start; i < sc->sc_coord_readouts + 2 + end; i++)
466 		x += data[i];
467 	x /= (end - start);
468 
469 #ifdef DEBUG_TSC
470 	device_printf(sc->sc_dev, "touchscreen x: %d, y: %d\n", x, y);
471 #endif
472 
473 #ifdef EVDEV_SUPPORT
474 	if ((sc->sc_x != x) || (sc->sc_y != y)) {
475 		sc->sc_x = x;
476 		sc->sc_y = y;
477 		ti_adc_ev_report(sc);
478 	}
479 #endif
480 }
481 
482 static void
483 ti_adc_intr_locked(struct ti_adc_softc *sc, uint32_t status)
484 {
485 	/* Read the available data. */
486 	if (status & ADC_IRQ_FIFO0_THRES)
487 		ti_adc_read_data(sc);
488 }
489 
490 static void
491 ti_adc_tsc_intr_locked(struct ti_adc_softc *sc, uint32_t status)
492 {
493 	/* Read the available data. */
494 	if (status & ADC_IRQ_FIFO1_THRES)
495 		ti_adc_tsc_read_data(sc);
496 
497 }
498 
499 static void
500 ti_adc_intr(void *arg)
501 {
502 	struct ti_adc_softc *sc;
503 	uint32_t status, rawstatus;
504 
505 	sc = (struct ti_adc_softc *)arg;
506 
507 	TI_ADC_LOCK(sc);
508 
509 	rawstatus = ADC_READ4(sc, ADC_IRQSTATUS_RAW);
510 	status = ADC_READ4(sc, ADC_IRQSTATUS);
511 
512 	if (rawstatus & ADC_IRQ_HW_PEN_ASYNC) {
513 		sc->sc_pen_down = 1;
514 		status |= ADC_IRQ_HW_PEN_ASYNC;
515 		ADC_WRITE4(sc, ADC_IRQENABLE_CLR,
516 			ADC_IRQ_HW_PEN_ASYNC);
517 #ifdef EVDEV_SUPPORT
518 		ti_adc_ev_report(sc);
519 #endif
520 	}
521 
522 	if (rawstatus & ADC_IRQ_PEN_UP) {
523 		sc->sc_pen_down = 0;
524 		status |= ADC_IRQ_PEN_UP;
525 #ifdef EVDEV_SUPPORT
526 		ti_adc_ev_report(sc);
527 #endif
528 	}
529 
530 	if (status & ADC_IRQ_FIFO0_THRES)
531 		ti_adc_intr_locked(sc, status);
532 
533 	if (status & ADC_IRQ_FIFO1_THRES)
534 		ti_adc_tsc_intr_locked(sc, status);
535 
536 	if (status) {
537 		/* ACK the interrupt. */
538 		ADC_WRITE4(sc, ADC_IRQSTATUS, status);
539 	}
540 
541 	/* Start the next conversion ? */
542 	if (status & ADC_IRQ_END_OF_SEQ)
543 		ti_adc_setup(sc);
544 
545 	TI_ADC_UNLOCK(sc);
546 }
547 
548 static void
549 ti_adc_sysctl_init(struct ti_adc_softc *sc)
550 {
551 	char pinbuf[3];
552 	struct sysctl_ctx_list *ctx;
553 	struct sysctl_oid *tree_node, *inp_node, *inpN_node;
554 	struct sysctl_oid_list *tree, *inp_tree, *inpN_tree;
555 	int ain, i;
556 
557 	/*
558 	 * Add per-pin sysctl tree/handlers.
559 	 */
560 	ctx = device_get_sysctl_ctx(sc->sc_dev);
561 	tree_node = device_get_sysctl_tree(sc->sc_dev);
562 	tree = SYSCTL_CHILDREN(tree_node);
563 	SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "clockdiv",
564 	    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,  sc, 0,
565 	    ti_adc_clockdiv_proc, "IU", "ADC clock prescaler");
566 	inp_node = SYSCTL_ADD_NODE(ctx, tree, OID_AUTO, "ain",
567 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "ADC inputs");
568 	inp_tree = SYSCTL_CHILDREN(inp_node);
569 
570 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
571 		ain = sc->sc_adc_channels[i];
572 
573 		snprintf(pinbuf, sizeof(pinbuf), "%d", ain);
574 		inpN_node = SYSCTL_ADD_NODE(ctx, inp_tree, OID_AUTO, pinbuf,
575 		    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "ADC input");
576 		inpN_tree = SYSCTL_CHILDREN(inpN_node);
577 
578 		SYSCTL_ADD_PROC(ctx, inpN_tree, OID_AUTO, "enable",
579 		    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,
580 		    &ti_adc_inputs[ain], 0,
581 		    ti_adc_enable_proc, "IU", "Enable ADC input");
582 		SYSCTL_ADD_PROC(ctx, inpN_tree, OID_AUTO, "open_delay",
583 		    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,
584 		    &ti_adc_inputs[ain], 0,
585 		    ti_adc_open_delay_proc, "IU", "ADC open delay");
586 		SYSCTL_ADD_PROC(ctx, inpN_tree, OID_AUTO, "samples_avg",
587 		    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,
588 		    &ti_adc_inputs[ain], 0,
589 		    ti_adc_samples_avg_proc, "IU", "ADC samples average");
590 		SYSCTL_ADD_INT(ctx, inpN_tree, OID_AUTO, "input",
591 		    CTLFLAG_RD, &ti_adc_inputs[ain].value, 0,
592 		    "Converted raw value for the ADC input");
593 	}
594 }
595 
596 static void
597 ti_adc_inputs_init(struct ti_adc_softc *sc)
598 {
599 	int ain, i;
600 	struct ti_adc_input *input;
601 
602 	TI_ADC_LOCK(sc);
603 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
604 		ain = sc->sc_adc_channels[i];
605 		input = &ti_adc_inputs[ain];
606 		input->sc = sc;
607 		input->input = ain;
608 		input->value = 0;
609 		input->enable = 0;
610 		input->samples = 0;
611 		ti_adc_input_setup(sc, ain);
612 	}
613 	TI_ADC_UNLOCK(sc);
614 }
615 
616 static void
617 ti_adc_tsc_init(struct ti_adc_softc *sc)
618 {
619 	int i, start_step, end_step;
620 	uint32_t stepconfig, val;
621 
622 	TI_ADC_LOCK(sc);
623 
624 	/* X coordinates */
625 	stepconfig = ADC_STEP_FIFO1 | (4 << ADC_STEP_AVG_SHIFT) |
626 	    ADC_STEP_MODE_HW_ONESHOT | sc->sc_xp_bit;
627 	if (sc->sc_tsc_wires == 4)
628 		stepconfig |= ADC_STEP_INP(sc->sc_yp_inp) | sc->sc_xn_bit;
629 	else if (sc->sc_tsc_wires == 5)
630 		stepconfig |= ADC_STEP_INP(4) |
631 			sc->sc_xn_bit | sc->sc_yn_bit | sc->sc_yp_bit;
632 	else if (sc->sc_tsc_wires == 8)
633 		stepconfig |= ADC_STEP_INP(sc->sc_yp_inp) | sc->sc_xn_bit;
634 
635 	start_step = ADC_STEPS - sc->sc_coord_readouts + 1;
636 	end_step = start_step + sc->sc_coord_readouts - 1;
637 	for (i = start_step; i <= end_step; i++) {
638 		ADC_WRITE4(sc, ADC_STEPCFG(i), stepconfig);
639 		ADC_WRITE4(sc, ADC_STEPDLY(i), STEPDLY_OPEN);
640 	}
641 
642 	/* Y coordinates */
643 	stepconfig = ADC_STEP_FIFO1 | (4 << ADC_STEP_AVG_SHIFT) |
644 	    ADC_STEP_MODE_HW_ONESHOT | sc->sc_yn_bit |
645 	    ADC_STEP_INM(8);
646 	if (sc->sc_tsc_wires == 4)
647 		stepconfig |= ADC_STEP_INP(sc->sc_xp_inp) | sc->sc_yp_bit;
648 	else if (sc->sc_tsc_wires == 5)
649 		stepconfig |= ADC_STEP_INP(4) |
650 			sc->sc_xp_bit | sc->sc_xn_bit | sc->sc_yp_bit;
651 	else if (sc->sc_tsc_wires == 8)
652 		stepconfig |= ADC_STEP_INP(sc->sc_xp_inp) | sc->sc_yp_bit;
653 
654 	start_step = ADC_STEPS - (sc->sc_coord_readouts*2 + 2) + 1;
655 	end_step = start_step + sc->sc_coord_readouts - 1;
656 	for (i = start_step; i <= end_step; i++) {
657 		ADC_WRITE4(sc, ADC_STEPCFG(i), stepconfig);
658 		ADC_WRITE4(sc, ADC_STEPDLY(i), STEPDLY_OPEN);
659 	}
660 
661 	/* Charge config */
662 	val = ADC_READ4(sc, ADC_IDLECONFIG);
663 	ADC_WRITE4(sc, ADC_TC_CHARGE_STEPCONFIG, val);
664 	ADC_WRITE4(sc, ADC_TC_CHARGE_DELAY, sc->sc_charge_delay);
665 
666 	/* 2 steps for Z */
667 	start_step = ADC_STEPS - (sc->sc_coord_readouts + 2) + 1;
668 	stepconfig = ADC_STEP_FIFO1 | (4 << ADC_STEP_AVG_SHIFT) |
669 	    ADC_STEP_MODE_HW_ONESHOT | sc->sc_yp_bit |
670 	    sc->sc_xn_bit | ADC_STEP_INP(sc->sc_xp_inp) |
671 	    ADC_STEP_INM(8);
672 	ADC_WRITE4(sc, ADC_STEPCFG(start_step), stepconfig);
673 	ADC_WRITE4(sc, ADC_STEPDLY(start_step), STEPDLY_OPEN);
674 	start_step++;
675 	stepconfig |= ADC_STEP_INP(sc->sc_yn_inp);
676 	ADC_WRITE4(sc, ADC_STEPCFG(start_step), stepconfig);
677 	ADC_WRITE4(sc, ADC_STEPDLY(start_step), STEPDLY_OPEN);
678 
679 	ADC_WRITE4(sc, ADC_FIFO1THRESHOLD, (sc->sc_coord_readouts*2 + 2) - 1);
680 
681 	sc->sc_tsc_enabled = 1;
682 	start_step = ADC_STEPS - (sc->sc_coord_readouts*2 + 2) + 1;
683 	end_step = ADC_STEPS;
684 	for (i = start_step; i <= end_step; i++) {
685 		sc->sc_tsc_enabled |= (1 << i);
686 	}
687 
688 	TI_ADC_UNLOCK(sc);
689 }
690 
691 static void
692 ti_adc_idlestep_init(struct ti_adc_softc *sc)
693 {
694 	uint32_t val;
695 
696 	val = ADC_STEP_YNN_SW | ADC_STEP_INM(8) | ADC_STEP_INP(8) | ADC_STEP_YPN_SW;
697 
698 	ADC_WRITE4(sc, ADC_IDLECONFIG, val);
699 }
700 
701 static int
702 ti_adc_config_wires(struct ti_adc_softc *sc, int *wire_configs, int nwire_configs)
703 {
704 	int i;
705 	int wire, ai;
706 
707 	for (i = 0; i < nwire_configs; i++) {
708 		wire = wire_configs[i] & 0xf;
709 		ai = (wire_configs[i] >> 4) & 0xf;
710 		switch (wire) {
711 		case ORDER_XP:
712 			sc->sc_xp_bit = ADC_STEP_XPP_SW;
713 			sc->sc_xp_inp = ai;
714 			break;
715 		case ORDER_XN:
716 			sc->sc_xn_bit = ADC_STEP_XNN_SW;
717 			sc->sc_xn_inp = ai;
718 			break;
719 		case ORDER_YP:
720 			sc->sc_yp_bit = ADC_STEP_YPP_SW;
721 			sc->sc_yp_inp = ai;
722 			break;
723 		case ORDER_YN:
724 			sc->sc_yn_bit = ADC_STEP_YNN_SW;
725 			sc->sc_yn_inp = ai;
726 			break;
727 		default:
728 			device_printf(sc->sc_dev, "Invalid wire config\n");
729 			return (-1);
730 		}
731 	}
732 	return (0);
733 }
734 
735 static int
736 ti_adc_probe(device_t dev)
737 {
738 
739 	if (!ofw_bus_is_compatible(dev, "ti,am3359-tscadc"))
740 		return (ENXIO);
741 	device_set_desc(dev, "TI ADC controller");
742 
743 	return (BUS_PROBE_DEFAULT);
744 }
745 
746 static int
747 ti_adc_attach(device_t dev)
748 {
749 	int err, rid, i;
750 	struct ti_adc_softc *sc;
751 	uint32_t rev, reg;
752 	phandle_t node, child;
753 	pcell_t cell;
754 	int *channels;
755 	int nwire_configs;
756 	int *wire_configs;
757 
758 	sc = device_get_softc(dev);
759 	sc->sc_dev = dev;
760 
761 	node = ofw_bus_get_node(dev);
762 
763 	sc->sc_tsc_wires = 0;
764 	sc->sc_coord_readouts = 1;
765 	sc->sc_x_plate_resistance = 0;
766 	sc->sc_charge_delay = DEFAULT_CHARGE_DELAY;
767 	/* Read "tsc" node properties */
768 	child = ofw_bus_find_child(node, "tsc");
769 	if (child != 0 && OF_hasprop(child, "ti,wires")) {
770 		if ((OF_getencprop(child, "ti,wires", &cell, sizeof(cell))) > 0)
771 			sc->sc_tsc_wires = cell;
772 		if ((OF_getencprop(child, "ti,coordinate-readouts", &cell,
773 		    sizeof(cell))) > 0)
774 			sc->sc_coord_readouts = cell;
775 		if ((OF_getencprop(child, "ti,x-plate-resistance", &cell,
776 		    sizeof(cell))) > 0)
777 			sc->sc_x_plate_resistance = cell;
778 		if ((OF_getencprop(child, "ti,charge-delay", &cell,
779 		    sizeof(cell))) > 0)
780 			sc->sc_charge_delay = cell;
781 		nwire_configs = OF_getencprop_alloc_multi(child,
782 		    "ti,wire-config", sizeof(*wire_configs),
783 		    (void **)&wire_configs);
784 		if (nwire_configs != sc->sc_tsc_wires) {
785 			device_printf(sc->sc_dev,
786 			    "invalid number of ti,wire-config: %d (should be %d)\n",
787 			    nwire_configs, sc->sc_tsc_wires);
788 			OF_prop_free(wire_configs);
789 			return (EINVAL);
790 		}
791 		err = ti_adc_config_wires(sc, wire_configs, nwire_configs);
792 		OF_prop_free(wire_configs);
793 		if (err)
794 			return (EINVAL);
795 	}
796 
797 	/* Read "adc" node properties */
798 	child = ofw_bus_find_child(node, "adc");
799 	if (child != 0) {
800 		sc->sc_adc_nchannels = OF_getencprop_alloc_multi(child,
801 		    "ti,adc-channels", sizeof(*channels), (void **)&channels);
802 		if (sc->sc_adc_nchannels > 0) {
803 			for (i = 0; i < sc->sc_adc_nchannels; i++)
804 				sc->sc_adc_channels[i] = channels[i];
805 			OF_prop_free(channels);
806 		}
807 	}
808 
809 	/* Sanity check FDT data */
810 	if (sc->sc_tsc_wires + sc->sc_adc_nchannels > TI_ADC_NPINS) {
811 		device_printf(dev, "total number of channels (%d) is larger than %d\n",
812 		    sc->sc_tsc_wires + sc->sc_adc_nchannels, TI_ADC_NPINS);
813 		return (ENXIO);
814 	}
815 
816 	rid = 0;
817 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
818 	    RF_ACTIVE);
819 	if (!sc->sc_mem_res) {
820 		device_printf(dev, "cannot allocate memory window\n");
821 		return (ENXIO);
822 	}
823 
824 	/* Activate the ADC_TSC module. */
825 	err = ti_sysc_clock_enable(device_get_parent(dev));
826 	if (err)
827 		return (err);
828 
829 	rid = 0;
830 	sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
831 	    RF_ACTIVE);
832 	if (!sc->sc_irq_res) {
833 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
834 		device_printf(dev, "cannot allocate interrupt\n");
835 		return (ENXIO);
836 	}
837 
838 	if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
839 	    NULL, ti_adc_intr, sc, &sc->sc_intrhand) != 0) {
840 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
841 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
842 		device_printf(dev, "Unable to setup the irq handler.\n");
843 		return (ENXIO);
844 	}
845 
846 	/* Check the ADC revision. */
847 	rev = ADC_READ4(sc, ti_sysc_get_rev_address_offset_host(device_get_parent(dev)));
848 	device_printf(dev,
849 	    "scheme: %#x func: %#x rtl: %d rev: %d.%d custom rev: %d\n",
850 	    (rev & ADC_REV_SCHEME_MSK) >> ADC_REV_SCHEME_SHIFT,
851 	    (rev & ADC_REV_FUNC_MSK) >> ADC_REV_FUNC_SHIFT,
852 	    (rev & ADC_REV_RTL_MSK) >> ADC_REV_RTL_SHIFT,
853 	    (rev & ADC_REV_MAJOR_MSK) >> ADC_REV_MAJOR_SHIFT,
854 	    rev & ADC_REV_MINOR_MSK,
855 	    (rev & ADC_REV_CUSTOM_MSK) >> ADC_REV_CUSTOM_SHIFT);
856 
857 	reg = ADC_READ4(sc, ADC_CTRL);
858 	ADC_WRITE4(sc, ADC_CTRL, reg | ADC_CTRL_STEP_WP | ADC_CTRL_STEP_ID);
859 
860 	/*
861 	 * Set the ADC prescaler to 2400 if touchscreen is not enabled
862 	 * and to 24 if it is.  This sets the ADC clock to ~10Khz and
863 	 * ~1Mhz respectively (CLK_M_OSC / prescaler).
864 	 */
865 	if (sc->sc_tsc_wires)
866 		ADC_WRITE4(sc, ADC_CLKDIV, 24 - 1);
867 	else
868 		ADC_WRITE4(sc, ADC_CLKDIV, 2400 - 1);
869 
870 	TI_ADC_LOCK_INIT(sc);
871 
872 	ti_adc_idlestep_init(sc);
873 	ti_adc_inputs_init(sc);
874 	ti_adc_sysctl_init(sc);
875 	ti_adc_tsc_init(sc);
876 
877 	TI_ADC_LOCK(sc);
878 	ti_adc_setup(sc);
879 	TI_ADC_UNLOCK(sc);
880 
881 #ifdef EVDEV_SUPPORT
882 	if (sc->sc_tsc_wires > 0) {
883 		sc->sc_evdev = evdev_alloc();
884 		evdev_set_name(sc->sc_evdev, device_get_desc(dev));
885 		evdev_set_phys(sc->sc_evdev, device_get_nameunit(dev));
886 		evdev_set_id(sc->sc_evdev, BUS_VIRTUAL, 0, 0, 0);
887 		evdev_support_prop(sc->sc_evdev, INPUT_PROP_DIRECT);
888 		evdev_support_event(sc->sc_evdev, EV_SYN);
889 		evdev_support_event(sc->sc_evdev, EV_ABS);
890 		evdev_support_event(sc->sc_evdev, EV_KEY);
891 
892 		evdev_support_abs(sc->sc_evdev, ABS_X, 0,
893 		    ADC_MAX_VALUE, 0, 0, 0);
894 		evdev_support_abs(sc->sc_evdev, ABS_Y, 0,
895 		    ADC_MAX_VALUE, 0, 0, 0);
896 
897 		evdev_support_key(sc->sc_evdev, BTN_TOUCH);
898 
899 		err = evdev_register(sc->sc_evdev);
900 		if (err) {
901 			device_printf(dev,
902 			    "failed to register evdev: error=%d\n", err);
903 			ti_adc_detach(dev);
904 			return (err);
905 		}
906 
907 		sc->sc_pen_down = 0;
908 		sc->sc_x = -1;
909 		sc->sc_y = -1;
910 	}
911 #endif /* EVDEV */
912 
913 	return (0);
914 }
915 
916 static int
917 ti_adc_detach(device_t dev)
918 {
919 	struct ti_adc_softc *sc;
920 
921 	sc = device_get_softc(dev);
922 
923 	/* Turn off the ADC. */
924 	TI_ADC_LOCK(sc);
925 	ti_adc_reset(sc);
926 	ti_adc_setup(sc);
927 
928 #ifdef EVDEV_SUPPORT
929 	evdev_free(sc->sc_evdev);
930 #endif
931 
932 	TI_ADC_UNLOCK(sc);
933 
934 	TI_ADC_LOCK_DESTROY(sc);
935 
936 	if (sc->sc_intrhand)
937 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
938 	if (sc->sc_irq_res)
939 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
940 	if (sc->sc_mem_res)
941 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
942 
943 	return (bus_generic_detach(dev));
944 }
945 
946 static device_method_t ti_adc_methods[] = {
947 	DEVMETHOD(device_probe,		ti_adc_probe),
948 	DEVMETHOD(device_attach,	ti_adc_attach),
949 	DEVMETHOD(device_detach,	ti_adc_detach),
950 
951 	DEVMETHOD_END
952 };
953 
954 static driver_t ti_adc_driver = {
955 	"ti_adc",
956 	ti_adc_methods,
957 	sizeof(struct ti_adc_softc),
958 };
959 
960 DRIVER_MODULE(ti_adc, simplebus, ti_adc_driver, 0, 0);
961 MODULE_VERSION(ti_adc, 1);
962 MODULE_DEPEND(ti_adc, simplebus, 1, 1, 1);
963 MODULE_DEPEND(ti_adc, ti_sysc, 1, 1, 1);
964 #ifdef EVDEV_SUPPORT
965 MODULE_DEPEND(ti_adc, evdev, 1, 1, 1);
966 #endif
967