xref: /freebsd/sys/arm/ti/ti_adc.c (revision 61ba55bcf70f2340f9c943c9571113b3fd8eda69)
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 #include "opt_evdev.h"
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 
34 #include <sys/conf.h>
35 #include <sys/kernel.h>
36 #include <sys/limits.h>
37 #include <sys/lock.h>
38 #include <sys/module.h>
39 #include <sys/mutex.h>
40 #include <sys/condvar.h>
41 #include <sys/resource.h>
42 #include <sys/rman.h>
43 #include <sys/sysctl.h>
44 #include <sys/selinfo.h>
45 #include <sys/poll.h>
46 #include <sys/uio.h>
47 
48 #include <machine/bus.h>
49 
50 #include <dev/ofw/openfirm.h>
51 #include <dev/ofw/ofw_bus.h>
52 #include <dev/ofw/ofw_bus_subr.h>
53 
54 #ifdef EVDEV_SUPPORT
55 #include <dev/evdev/input.h>
56 #include <dev/evdev/evdev.h>
57 #endif
58 
59 #include <arm/ti/ti_sysc.h>
60 #include <arm/ti/ti_adcreg.h>
61 #include <arm/ti/ti_adcvar.h>
62 
63 #undef	DEBUG_TSC
64 
65 #define	DEFAULT_CHARGE_DELAY	0x400
66 #define	STEPDLY_OPEN		0x98
67 
68 #define	ORDER_XP	0
69 #define	ORDER_XN	1
70 #define	ORDER_YP	2
71 #define	ORDER_YN	3
72 
73 /* Define our 8 steps, one for each input channel. */
74 static struct ti_adc_input ti_adc_inputs[TI_ADC_NPINS] = {
75 	{ .stepconfig = ADC_STEPCFG(1), .stepdelay = ADC_STEPDLY(1) },
76 	{ .stepconfig = ADC_STEPCFG(2), .stepdelay = ADC_STEPDLY(2) },
77 	{ .stepconfig = ADC_STEPCFG(3), .stepdelay = ADC_STEPDLY(3) },
78 	{ .stepconfig = ADC_STEPCFG(4), .stepdelay = ADC_STEPDLY(4) },
79 	{ .stepconfig = ADC_STEPCFG(5), .stepdelay = ADC_STEPDLY(5) },
80 	{ .stepconfig = ADC_STEPCFG(6), .stepdelay = ADC_STEPDLY(6) },
81 	{ .stepconfig = ADC_STEPCFG(7), .stepdelay = ADC_STEPDLY(7) },
82 	{ .stepconfig = ADC_STEPCFG(8), .stepdelay = ADC_STEPDLY(8) },
83 };
84 
85 static int ti_adc_samples[5] = { 0, 2, 4, 8, 16 };
86 
87 static int ti_adc_detach(device_t dev);
88 
89 #ifdef EVDEV_SUPPORT
90 static void
91 ti_adc_ev_report(struct ti_adc_softc *sc)
92 {
93 
94 	evdev_push_event(sc->sc_evdev, EV_ABS, ABS_X, sc->sc_x);
95 	evdev_push_event(sc->sc_evdev, EV_ABS, ABS_Y, sc->sc_y);
96 	evdev_push_event(sc->sc_evdev, EV_KEY, BTN_TOUCH, sc->sc_pen_down);
97 	evdev_sync(sc->sc_evdev);
98 }
99 #endif /* EVDEV */
100 
101 static void
102 ti_adc_enable(struct ti_adc_softc *sc)
103 {
104 	uint32_t reg;
105 
106 	TI_ADC_LOCK_ASSERT(sc);
107 
108 	if (sc->sc_last_state == 1)
109 		return;
110 
111 	/* Enable the FIFO0 threshold and the end of sequence interrupt. */
112 	ADC_WRITE4(sc, ADC_IRQENABLE_SET,
113 	    ADC_IRQ_FIFO0_THRES | ADC_IRQ_FIFO1_THRES | ADC_IRQ_END_OF_SEQ);
114 
115 	reg = ADC_CTRL_STEP_WP | ADC_CTRL_STEP_ID;
116 	if (sc->sc_tsc_wires > 0) {
117 		reg |= ADC_CTRL_TSC_ENABLE;
118 		switch (sc->sc_tsc_wires) {
119 		case 4:
120 			reg |= ADC_CTRL_TSC_4WIRE;
121 			break;
122 		case 5:
123 			reg |= ADC_CTRL_TSC_5WIRE;
124 			break;
125 		case 8:
126 			reg |= ADC_CTRL_TSC_8WIRE;
127 			break;
128 		default:
129 			break;
130 		}
131 	}
132 	reg |= ADC_CTRL_ENABLE;
133 	/* Enable the ADC.  Run thru enabled steps, start the conversions. */
134 	ADC_WRITE4(sc, ADC_CTRL, reg);
135 
136 	sc->sc_last_state = 1;
137 }
138 
139 static void
140 ti_adc_disable(struct ti_adc_softc *sc)
141 {
142 	int count;
143 
144 	TI_ADC_LOCK_ASSERT(sc);
145 
146 	if (sc->sc_last_state == 0)
147 		return;
148 
149 	/* Disable all the enabled steps. */
150 	ADC_WRITE4(sc, ADC_STEPENABLE, 0);
151 
152 	/* Disable the ADC. */
153 	ADC_WRITE4(sc, ADC_CTRL, ADC_READ4(sc, ADC_CTRL) & ~ADC_CTRL_ENABLE);
154 
155 	/* Disable the FIFO0 threshold and the end of sequence interrupt. */
156 	ADC_WRITE4(sc, ADC_IRQENABLE_CLR,
157 	    ADC_IRQ_FIFO0_THRES | ADC_IRQ_FIFO1_THRES | ADC_IRQ_END_OF_SEQ);
158 
159 	/* ACK any pending interrupt. */
160 	ADC_WRITE4(sc, ADC_IRQSTATUS, ADC_READ4(sc, ADC_IRQSTATUS));
161 
162 	/* Drain the FIFO data. */
163 	count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
164 	while (count > 0) {
165 		(void)ADC_READ4(sc, ADC_FIFO0DATA);
166 		count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
167 	}
168 
169 	count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
170 	while (count > 0) {
171 		(void)ADC_READ4(sc, ADC_FIFO1DATA);
172 		count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
173 	}
174 
175 	sc->sc_last_state = 0;
176 }
177 
178 static int
179 ti_adc_setup(struct ti_adc_softc *sc)
180 {
181 	int ain, i;
182 	uint32_t enabled;
183 
184 	TI_ADC_LOCK_ASSERT(sc);
185 
186 	/* Check for enabled inputs. */
187 	enabled = sc->sc_tsc_enabled;
188 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
189 		ain = sc->sc_adc_channels[i];
190 		if (ti_adc_inputs[ain].enable)
191 			enabled |= (1U << (ain + 1));
192 	}
193 
194 	/* Set the ADC global status. */
195 	if (enabled != 0) {
196 		ti_adc_enable(sc);
197 		/* Update the enabled steps. */
198 		if (enabled != ADC_READ4(sc, ADC_STEPENABLE))
199 			ADC_WRITE4(sc, ADC_STEPENABLE, enabled);
200 	} else
201 		ti_adc_disable(sc);
202 
203 	return (0);
204 }
205 
206 static void
207 ti_adc_input_setup(struct ti_adc_softc *sc, int32_t ain)
208 {
209 	struct ti_adc_input *input;
210 	uint32_t reg, val;
211 
212 	TI_ADC_LOCK_ASSERT(sc);
213 
214 	input = &ti_adc_inputs[ain];
215 	reg = input->stepconfig;
216 	val = ADC_READ4(sc, reg);
217 
218 	/* Set single ended operation. */
219 	val &= ~ADC_STEP_DIFF_CNTRL;
220 
221 	/* Set the negative voltage reference. */
222 	val &= ~ADC_STEP_RFM_MSK;
223 
224 	/* Set the positive voltage reference. */
225 	val &= ~ADC_STEP_RFP_MSK;
226 
227 	/* Set the samples average. */
228 	val &= ~ADC_STEP_AVG_MSK;
229 	val |= input->samples << ADC_STEP_AVG_SHIFT;
230 
231 	/* Select the desired input. */
232 	val &= ~ADC_STEP_INP_MSK;
233 	val |= ain << ADC_STEP_INP_SHIFT;
234 
235 	/* Set the ADC to one-shot mode. */
236 	val &= ~ADC_STEP_MODE_MSK;
237 
238 	ADC_WRITE4(sc, reg, val);
239 }
240 
241 static void
242 ti_adc_reset(struct ti_adc_softc *sc)
243 {
244 	int ain, i;
245 
246 	TI_ADC_LOCK_ASSERT(sc);
247 
248 	/* Disable all the inputs. */
249 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
250 		ain = sc->sc_adc_channels[i];
251 		ti_adc_inputs[ain].enable = 0;
252 	}
253 }
254 
255 static int
256 ti_adc_clockdiv_proc(SYSCTL_HANDLER_ARGS)
257 {
258 	int error, reg;
259 	struct ti_adc_softc *sc;
260 
261 	sc = (struct ti_adc_softc *)arg1;
262 
263 	TI_ADC_LOCK(sc);
264 	reg = (int)ADC_READ4(sc, ADC_CLKDIV) + 1;
265 	TI_ADC_UNLOCK(sc);
266 
267 	error = sysctl_handle_int(oidp, &reg, sizeof(reg), req);
268 	if (error != 0 || req->newptr == NULL)
269 		return (error);
270 
271 	/*
272 	 * The actual written value is the prescaler setting - 1.
273 	 * Enforce a minimum value of 10 (i.e. 9) which limits the maximum
274 	 * ADC clock to ~2.4Mhz (CLK_M_OSC / 10).
275 	 */
276 	reg--;
277 	if (reg < 9)
278 		reg = 9;
279 	if (reg > USHRT_MAX)
280 		reg = USHRT_MAX;
281 
282 	TI_ADC_LOCK(sc);
283 	/* Disable the ADC. */
284 	ti_adc_disable(sc);
285 	/* Update the ADC prescaler setting. */
286 	ADC_WRITE4(sc, ADC_CLKDIV, reg);
287 	/* Enable the ADC again. */
288 	ti_adc_setup(sc);
289 	TI_ADC_UNLOCK(sc);
290 
291 	return (0);
292 }
293 
294 static int
295 ti_adc_enable_proc(SYSCTL_HANDLER_ARGS)
296 {
297 	int error;
298 	int32_t enable;
299 	struct ti_adc_softc *sc;
300 	struct ti_adc_input *input;
301 
302 	input = (struct ti_adc_input *)arg1;
303 	sc = input->sc;
304 
305 	enable = input->enable;
306 	error = sysctl_handle_int(oidp, &enable, sizeof(enable),
307 	    req);
308 	if (error != 0 || req->newptr == NULL)
309 		return (error);
310 
311 	if (enable)
312 		enable = 1;
313 
314 	TI_ADC_LOCK(sc);
315 	/* Setup the ADC as needed. */
316 	if (input->enable != enable) {
317 		input->enable = enable;
318 		ti_adc_setup(sc);
319 		if (input->enable == 0)
320 			input->value = 0;
321 	}
322 	TI_ADC_UNLOCK(sc);
323 
324 	return (0);
325 }
326 
327 static int
328 ti_adc_open_delay_proc(SYSCTL_HANDLER_ARGS)
329 {
330 	int error, reg;
331 	struct ti_adc_softc *sc;
332 	struct ti_adc_input *input;
333 
334 	input = (struct ti_adc_input *)arg1;
335 	sc = input->sc;
336 
337 	TI_ADC_LOCK(sc);
338 	reg = (int)ADC_READ4(sc, input->stepdelay) & ADC_STEP_OPEN_DELAY;
339 	TI_ADC_UNLOCK(sc);
340 
341 	error = sysctl_handle_int(oidp, &reg, sizeof(reg), req);
342 	if (error != 0 || req->newptr == NULL)
343 		return (error);
344 
345 	if (reg < 0)
346 		reg = 0;
347 
348 	TI_ADC_LOCK(sc);
349 	ADC_WRITE4(sc, input->stepdelay, reg & ADC_STEP_OPEN_DELAY);
350 	TI_ADC_UNLOCK(sc);
351 
352 	return (0);
353 }
354 
355 static int
356 ti_adc_samples_avg_proc(SYSCTL_HANDLER_ARGS)
357 {
358 	int error, samples, i;
359 	struct ti_adc_softc *sc;
360 	struct ti_adc_input *input;
361 
362 	input = (struct ti_adc_input *)arg1;
363 	sc = input->sc;
364 
365 	if (input->samples > nitems(ti_adc_samples))
366 		input->samples = nitems(ti_adc_samples);
367 	samples = ti_adc_samples[input->samples];
368 
369 	error = sysctl_handle_int(oidp, &samples, 0, req);
370 	if (error != 0 || req->newptr == NULL)
371 		return (error);
372 
373 	TI_ADC_LOCK(sc);
374 	if (samples != ti_adc_samples[input->samples]) {
375 		input->samples = 0;
376 		for (i = 0; i < nitems(ti_adc_samples); i++)
377 			if (samples >= ti_adc_samples[i])
378 				input->samples = i;
379 		ti_adc_input_setup(sc, input->input);
380 	}
381 	TI_ADC_UNLOCK(sc);
382 
383 	return (error);
384 }
385 
386 static void
387 ti_adc_read_data(struct ti_adc_softc *sc)
388 {
389 	int count, ain;
390 	struct ti_adc_input *input;
391 	uint32_t data;
392 
393 	TI_ADC_LOCK_ASSERT(sc);
394 
395 	/* Read the available data. */
396 	count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
397 	while (count > 0) {
398 		data = ADC_READ4(sc, ADC_FIFO0DATA);
399 		ain = (data & ADC_FIFO_STEP_ID_MSK) >> ADC_FIFO_STEP_ID_SHIFT;
400 		input = &ti_adc_inputs[ain];
401 		if (input->enable == 0)
402 			input->value = 0;
403 		else
404 			input->value = (int32_t)(data & ADC_FIFO_DATA_MSK);
405 		count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
406 	}
407 }
408 
409 static int
410 cmp_values(const void *a, const void *b)
411 {
412 	const uint32_t *v1, *v2;
413 	v1 = a;
414 	v2 = b;
415 	if (*v1 < *v2)
416 		return -1;
417 	if (*v1 > *v2)
418 		return 1;
419 
420 	return (0);
421 }
422 
423 static void
424 ti_adc_tsc_read_data(struct ti_adc_softc *sc)
425 {
426 	int count;
427 	uint32_t data[16];
428 	uint32_t x, y;
429 	int i, start, end;
430 
431 	TI_ADC_LOCK_ASSERT(sc);
432 
433 	/* Read the available data. */
434 	count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
435 	if (count == 0)
436 		return;
437 
438 	i = 0;
439 	while (count > 0) {
440 		data[i++] = ADC_READ4(sc, ADC_FIFO1DATA) & ADC_FIFO_DATA_MSK;
441 		count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
442 	}
443 
444 	if (sc->sc_coord_readouts > 3) {
445 		start = 1;
446 		end = sc->sc_coord_readouts - 1;
447 		qsort(data, sc->sc_coord_readouts,
448 			sizeof(data[0]), &cmp_values);
449 		qsort(&data[sc->sc_coord_readouts + 2],
450 			sc->sc_coord_readouts,
451 			sizeof(data[0]), &cmp_values);
452 	}
453 	else {
454 		start = 0;
455 		end = sc->sc_coord_readouts;
456 	}
457 
458 	x = y = 0;
459 	for (i = start; i < end; i++)
460 		y += data[i];
461 	y /= (end - start);
462 
463 	for (i = sc->sc_coord_readouts + 2 + start; i < sc->sc_coord_readouts + 2 + end; i++)
464 		x += data[i];
465 	x /= (end - start);
466 
467 #ifdef DEBUG_TSC
468 	device_printf(sc->sc_dev, "touchscreen x: %d, y: %d\n", x, y);
469 #endif
470 
471 #ifdef EVDEV_SUPPORT
472 	if ((sc->sc_x != x) || (sc->sc_y != y)) {
473 		sc->sc_x = x;
474 		sc->sc_y = y;
475 		ti_adc_ev_report(sc);
476 	}
477 #endif
478 }
479 
480 static void
481 ti_adc_intr_locked(struct ti_adc_softc *sc, uint32_t status)
482 {
483 	/* Read the available data. */
484 	if (status & ADC_IRQ_FIFO0_THRES)
485 		ti_adc_read_data(sc);
486 }
487 
488 static void
489 ti_adc_tsc_intr_locked(struct ti_adc_softc *sc, uint32_t status)
490 {
491 	/* Read the available data. */
492 	if (status & ADC_IRQ_FIFO1_THRES)
493 		ti_adc_tsc_read_data(sc);
494 
495 }
496 
497 static void
498 ti_adc_intr(void *arg)
499 {
500 	struct ti_adc_softc *sc;
501 	uint32_t status, rawstatus;
502 
503 	sc = (struct ti_adc_softc *)arg;
504 
505 	TI_ADC_LOCK(sc);
506 
507 	rawstatus = ADC_READ4(sc, ADC_IRQSTATUS_RAW);
508 	status = ADC_READ4(sc, ADC_IRQSTATUS);
509 
510 	if (rawstatus & ADC_IRQ_HW_PEN_ASYNC) {
511 		sc->sc_pen_down = 1;
512 		status |= ADC_IRQ_HW_PEN_ASYNC;
513 		ADC_WRITE4(sc, ADC_IRQENABLE_CLR,
514 			ADC_IRQ_HW_PEN_ASYNC);
515 #ifdef EVDEV_SUPPORT
516 		ti_adc_ev_report(sc);
517 #endif
518 	}
519 
520 	if (rawstatus & ADC_IRQ_PEN_UP) {
521 		sc->sc_pen_down = 0;
522 		status |= ADC_IRQ_PEN_UP;
523 #ifdef EVDEV_SUPPORT
524 		ti_adc_ev_report(sc);
525 #endif
526 	}
527 
528 	if (status & ADC_IRQ_FIFO0_THRES)
529 		ti_adc_intr_locked(sc, status);
530 
531 	if (status & ADC_IRQ_FIFO1_THRES)
532 		ti_adc_tsc_intr_locked(sc, status);
533 
534 	if (status) {
535 		/* ACK the interrupt. */
536 		ADC_WRITE4(sc, ADC_IRQSTATUS, status);
537 	}
538 
539 	/* Start the next conversion ? */
540 	if (status & ADC_IRQ_END_OF_SEQ)
541 		ti_adc_setup(sc);
542 
543 	TI_ADC_UNLOCK(sc);
544 }
545 
546 static void
547 ti_adc_sysctl_init(struct ti_adc_softc *sc)
548 {
549 	char pinbuf[3];
550 	struct sysctl_ctx_list *ctx;
551 	struct sysctl_oid *tree_node, *inp_node, *inpN_node;
552 	struct sysctl_oid_list *tree, *inp_tree, *inpN_tree;
553 	int ain, i;
554 
555 	/*
556 	 * Add per-pin sysctl tree/handlers.
557 	 */
558 	ctx = device_get_sysctl_ctx(sc->sc_dev);
559 	tree_node = device_get_sysctl_tree(sc->sc_dev);
560 	tree = SYSCTL_CHILDREN(tree_node);
561 	SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "clockdiv",
562 	    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,  sc, 0,
563 	    ti_adc_clockdiv_proc, "IU", "ADC clock prescaler");
564 	inp_node = SYSCTL_ADD_NODE(ctx, tree, OID_AUTO, "ain",
565 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "ADC inputs");
566 	inp_tree = SYSCTL_CHILDREN(inp_node);
567 
568 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
569 		ain = sc->sc_adc_channels[i];
570 
571 		snprintf(pinbuf, sizeof(pinbuf), "%d", ain);
572 		inpN_node = SYSCTL_ADD_NODE(ctx, inp_tree, OID_AUTO, pinbuf,
573 		    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "ADC input");
574 		inpN_tree = SYSCTL_CHILDREN(inpN_node);
575 
576 		SYSCTL_ADD_PROC(ctx, inpN_tree, OID_AUTO, "enable",
577 		    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,
578 		    &ti_adc_inputs[ain], 0,
579 		    ti_adc_enable_proc, "IU", "Enable ADC input");
580 		SYSCTL_ADD_PROC(ctx, inpN_tree, OID_AUTO, "open_delay",
581 		    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,
582 		    &ti_adc_inputs[ain], 0,
583 		    ti_adc_open_delay_proc, "IU", "ADC open delay");
584 		SYSCTL_ADD_PROC(ctx, inpN_tree, OID_AUTO, "samples_avg",
585 		    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,
586 		    &ti_adc_inputs[ain], 0,
587 		    ti_adc_samples_avg_proc, "IU", "ADC samples average");
588 		SYSCTL_ADD_INT(ctx, inpN_tree, OID_AUTO, "input",
589 		    CTLFLAG_RD, &ti_adc_inputs[ain].value, 0,
590 		    "Converted raw value for the ADC input");
591 	}
592 }
593 
594 static void
595 ti_adc_inputs_init(struct ti_adc_softc *sc)
596 {
597 	int ain, i;
598 	struct ti_adc_input *input;
599 
600 	TI_ADC_LOCK(sc);
601 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
602 		ain = sc->sc_adc_channels[i];
603 		input = &ti_adc_inputs[ain];
604 		input->sc = sc;
605 		input->input = ain;
606 		input->value = 0;
607 		input->enable = 0;
608 		input->samples = 0;
609 		ti_adc_input_setup(sc, ain);
610 	}
611 	TI_ADC_UNLOCK(sc);
612 }
613 
614 static void
615 ti_adc_tsc_init(struct ti_adc_softc *sc)
616 {
617 	int i, start_step, end_step;
618 	uint32_t stepconfig, val;
619 
620 	TI_ADC_LOCK(sc);
621 
622 	/* X coordinates */
623 	stepconfig = ADC_STEP_FIFO1 | (4 << ADC_STEP_AVG_SHIFT) |
624 	    ADC_STEP_MODE_HW_ONESHOT | sc->sc_xp_bit;
625 	if (sc->sc_tsc_wires == 4)
626 		stepconfig |= ADC_STEP_INP(sc->sc_yp_inp) | sc->sc_xn_bit;
627 	else if (sc->sc_tsc_wires == 5)
628 		stepconfig |= ADC_STEP_INP(4) |
629 			sc->sc_xn_bit | sc->sc_yn_bit | sc->sc_yp_bit;
630 	else if (sc->sc_tsc_wires == 8)
631 		stepconfig |= ADC_STEP_INP(sc->sc_yp_inp) | sc->sc_xn_bit;
632 
633 	start_step = ADC_STEPS - sc->sc_coord_readouts + 1;
634 	end_step = start_step + sc->sc_coord_readouts - 1;
635 	for (i = start_step; i <= end_step; i++) {
636 		ADC_WRITE4(sc, ADC_STEPCFG(i), stepconfig);
637 		ADC_WRITE4(sc, ADC_STEPDLY(i), STEPDLY_OPEN);
638 	}
639 
640 	/* Y coordinates */
641 	stepconfig = ADC_STEP_FIFO1 | (4 << ADC_STEP_AVG_SHIFT) |
642 	    ADC_STEP_MODE_HW_ONESHOT | sc->sc_yn_bit |
643 	    ADC_STEP_INM(8);
644 	if (sc->sc_tsc_wires == 4)
645 		stepconfig |= ADC_STEP_INP(sc->sc_xp_inp) | sc->sc_yp_bit;
646 	else if (sc->sc_tsc_wires == 5)
647 		stepconfig |= ADC_STEP_INP(4) |
648 			sc->sc_xp_bit | sc->sc_xn_bit | sc->sc_yp_bit;
649 	else if (sc->sc_tsc_wires == 8)
650 		stepconfig |= ADC_STEP_INP(sc->sc_xp_inp) | sc->sc_yp_bit;
651 
652 	start_step = ADC_STEPS - (sc->sc_coord_readouts*2 + 2) + 1;
653 	end_step = start_step + sc->sc_coord_readouts - 1;
654 	for (i = start_step; i <= end_step; i++) {
655 		ADC_WRITE4(sc, ADC_STEPCFG(i), stepconfig);
656 		ADC_WRITE4(sc, ADC_STEPDLY(i), STEPDLY_OPEN);
657 	}
658 
659 	/* Charge config */
660 	val = ADC_READ4(sc, ADC_IDLECONFIG);
661 	ADC_WRITE4(sc, ADC_TC_CHARGE_STEPCONFIG, val);
662 	ADC_WRITE4(sc, ADC_TC_CHARGE_DELAY, sc->sc_charge_delay);
663 
664 	/* 2 steps for Z */
665 	start_step = ADC_STEPS - (sc->sc_coord_readouts + 2) + 1;
666 	stepconfig = ADC_STEP_FIFO1 | (4 << ADC_STEP_AVG_SHIFT) |
667 	    ADC_STEP_MODE_HW_ONESHOT | sc->sc_yp_bit |
668 	    sc->sc_xn_bit | ADC_STEP_INP(sc->sc_xp_inp) |
669 	    ADC_STEP_INM(8);
670 	ADC_WRITE4(sc, ADC_STEPCFG(start_step), stepconfig);
671 	ADC_WRITE4(sc, ADC_STEPDLY(start_step), STEPDLY_OPEN);
672 	start_step++;
673 	stepconfig |= ADC_STEP_INP(sc->sc_yn_inp);
674 	ADC_WRITE4(sc, ADC_STEPCFG(start_step), stepconfig);
675 	ADC_WRITE4(sc, ADC_STEPDLY(start_step), STEPDLY_OPEN);
676 
677 	ADC_WRITE4(sc, ADC_FIFO1THRESHOLD, (sc->sc_coord_readouts*2 + 2) - 1);
678 
679 	sc->sc_tsc_enabled = 1;
680 	start_step = ADC_STEPS - (sc->sc_coord_readouts*2 + 2) + 1;
681 	end_step = ADC_STEPS;
682 	for (i = start_step; i <= end_step; i++) {
683 		sc->sc_tsc_enabled |= (1 << i);
684 	}
685 
686 	TI_ADC_UNLOCK(sc);
687 }
688 
689 static void
690 ti_adc_idlestep_init(struct ti_adc_softc *sc)
691 {
692 	uint32_t val;
693 
694 	val = ADC_STEP_YNN_SW | ADC_STEP_INM(8) | ADC_STEP_INP(8) | ADC_STEP_YPN_SW;
695 
696 	ADC_WRITE4(sc, ADC_IDLECONFIG, val);
697 }
698 
699 static int
700 ti_adc_config_wires(struct ti_adc_softc *sc, int *wire_configs, int nwire_configs)
701 {
702 	int i;
703 	int wire, ai;
704 
705 	for (i = 0; i < nwire_configs; i++) {
706 		wire = wire_configs[i] & 0xf;
707 		ai = (wire_configs[i] >> 4) & 0xf;
708 		switch (wire) {
709 		case ORDER_XP:
710 			sc->sc_xp_bit = ADC_STEP_XPP_SW;
711 			sc->sc_xp_inp = ai;
712 			break;
713 		case ORDER_XN:
714 			sc->sc_xn_bit = ADC_STEP_XNN_SW;
715 			sc->sc_xn_inp = ai;
716 			break;
717 		case ORDER_YP:
718 			sc->sc_yp_bit = ADC_STEP_YPP_SW;
719 			sc->sc_yp_inp = ai;
720 			break;
721 		case ORDER_YN:
722 			sc->sc_yn_bit = ADC_STEP_YNN_SW;
723 			sc->sc_yn_inp = ai;
724 			break;
725 		default:
726 			device_printf(sc->sc_dev, "Invalid wire config\n");
727 			return (-1);
728 		}
729 	}
730 	return (0);
731 }
732 
733 static int
734 ti_adc_probe(device_t dev)
735 {
736 
737 	if (!ofw_bus_is_compatible(dev, "ti,am3359-tscadc"))
738 		return (ENXIO);
739 	device_set_desc(dev, "TI ADC controller");
740 
741 	return (BUS_PROBE_DEFAULT);
742 }
743 
744 static int
745 ti_adc_attach(device_t dev)
746 {
747 	int err, rid, i;
748 	struct ti_adc_softc *sc;
749 	uint32_t rev, reg;
750 	phandle_t node, child;
751 	pcell_t cell;
752 	int *channels;
753 	int nwire_configs;
754 	int *wire_configs;
755 
756 	sc = device_get_softc(dev);
757 	sc->sc_dev = dev;
758 
759 	node = ofw_bus_get_node(dev);
760 
761 	sc->sc_tsc_wires = 0;
762 	sc->sc_coord_readouts = 1;
763 	sc->sc_x_plate_resistance = 0;
764 	sc->sc_charge_delay = DEFAULT_CHARGE_DELAY;
765 	/* Read "tsc" node properties */
766 	child = ofw_bus_find_child(node, "tsc");
767 	if (child != 0 && OF_hasprop(child, "ti,wires")) {
768 		if ((OF_getencprop(child, "ti,wires", &cell, sizeof(cell))) > 0)
769 			sc->sc_tsc_wires = cell;
770 		if ((OF_getencprop(child, "ti,coordinate-readouts", &cell,
771 		    sizeof(cell))) > 0)
772 			sc->sc_coord_readouts = cell;
773 		if ((OF_getencprop(child, "ti,x-plate-resistance", &cell,
774 		    sizeof(cell))) > 0)
775 			sc->sc_x_plate_resistance = cell;
776 		if ((OF_getencprop(child, "ti,charge-delay", &cell,
777 		    sizeof(cell))) > 0)
778 			sc->sc_charge_delay = cell;
779 		nwire_configs = OF_getencprop_alloc_multi(child,
780 		    "ti,wire-config", sizeof(*wire_configs),
781 		    (void **)&wire_configs);
782 		if (nwire_configs != sc->sc_tsc_wires) {
783 			device_printf(sc->sc_dev,
784 			    "invalid number of ti,wire-config: %d (should be %d)\n",
785 			    nwire_configs, sc->sc_tsc_wires);
786 			OF_prop_free(wire_configs);
787 			return (EINVAL);
788 		}
789 		err = ti_adc_config_wires(sc, wire_configs, nwire_configs);
790 		OF_prop_free(wire_configs);
791 		if (err)
792 			return (EINVAL);
793 	}
794 
795 	/* Read "adc" node properties */
796 	child = ofw_bus_find_child(node, "adc");
797 	if (child != 0) {
798 		sc->sc_adc_nchannels = OF_getencprop_alloc_multi(child,
799 		    "ti,adc-channels", sizeof(*channels), (void **)&channels);
800 		if (sc->sc_adc_nchannels > 0) {
801 			for (i = 0; i < sc->sc_adc_nchannels; i++)
802 				sc->sc_adc_channels[i] = channels[i];
803 			OF_prop_free(channels);
804 		}
805 	}
806 
807 	/* Sanity check FDT data */
808 	if (sc->sc_tsc_wires + sc->sc_adc_nchannels > TI_ADC_NPINS) {
809 		device_printf(dev, "total number of channels (%d) is larger than %d\n",
810 		    sc->sc_tsc_wires + sc->sc_adc_nchannels, TI_ADC_NPINS);
811 		return (ENXIO);
812 	}
813 
814 	rid = 0;
815 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
816 	    RF_ACTIVE);
817 	if (!sc->sc_mem_res) {
818 		device_printf(dev, "cannot allocate memory window\n");
819 		return (ENXIO);
820 	}
821 
822 	/* Activate the ADC_TSC module. */
823 	err = ti_sysc_clock_enable(device_get_parent(dev));
824 	if (err)
825 		return (err);
826 
827 	rid = 0;
828 	sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
829 	    RF_ACTIVE);
830 	if (!sc->sc_irq_res) {
831 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
832 		device_printf(dev, "cannot allocate interrupt\n");
833 		return (ENXIO);
834 	}
835 
836 	if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
837 	    NULL, ti_adc_intr, sc, &sc->sc_intrhand) != 0) {
838 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
839 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
840 		device_printf(dev, "Unable to setup the irq handler.\n");
841 		return (ENXIO);
842 	}
843 
844 	/* Check the ADC revision. */
845 	rev = ADC_READ4(sc, ti_sysc_get_rev_address_offset_host(device_get_parent(dev)));
846 	device_printf(dev,
847 	    "scheme: %#x func: %#x rtl: %d rev: %d.%d custom rev: %d\n",
848 	    (rev & ADC_REV_SCHEME_MSK) >> ADC_REV_SCHEME_SHIFT,
849 	    (rev & ADC_REV_FUNC_MSK) >> ADC_REV_FUNC_SHIFT,
850 	    (rev & ADC_REV_RTL_MSK) >> ADC_REV_RTL_SHIFT,
851 	    (rev & ADC_REV_MAJOR_MSK) >> ADC_REV_MAJOR_SHIFT,
852 	    rev & ADC_REV_MINOR_MSK,
853 	    (rev & ADC_REV_CUSTOM_MSK) >> ADC_REV_CUSTOM_SHIFT);
854 
855 	reg = ADC_READ4(sc, ADC_CTRL);
856 	ADC_WRITE4(sc, ADC_CTRL, reg | ADC_CTRL_STEP_WP | ADC_CTRL_STEP_ID);
857 
858 	/*
859 	 * Set the ADC prescaler to 2400 if touchscreen is not enabled
860 	 * and to 24 if it is.  This sets the ADC clock to ~10Khz and
861 	 * ~1Mhz respectively (CLK_M_OSC / prescaler).
862 	 */
863 	if (sc->sc_tsc_wires)
864 		ADC_WRITE4(sc, ADC_CLKDIV, 24 - 1);
865 	else
866 		ADC_WRITE4(sc, ADC_CLKDIV, 2400 - 1);
867 
868 	TI_ADC_LOCK_INIT(sc);
869 
870 	ti_adc_idlestep_init(sc);
871 	ti_adc_inputs_init(sc);
872 	ti_adc_sysctl_init(sc);
873 	ti_adc_tsc_init(sc);
874 
875 	TI_ADC_LOCK(sc);
876 	ti_adc_setup(sc);
877 	TI_ADC_UNLOCK(sc);
878 
879 #ifdef EVDEV_SUPPORT
880 	if (sc->sc_tsc_wires > 0) {
881 		sc->sc_evdev = evdev_alloc();
882 		evdev_set_name(sc->sc_evdev, device_get_desc(dev));
883 		evdev_set_phys(sc->sc_evdev, device_get_nameunit(dev));
884 		evdev_set_id(sc->sc_evdev, BUS_VIRTUAL, 0, 0, 0);
885 		evdev_support_prop(sc->sc_evdev, INPUT_PROP_DIRECT);
886 		evdev_support_event(sc->sc_evdev, EV_SYN);
887 		evdev_support_event(sc->sc_evdev, EV_ABS);
888 		evdev_support_event(sc->sc_evdev, EV_KEY);
889 
890 		evdev_support_abs(sc->sc_evdev, ABS_X, 0,
891 		    ADC_MAX_VALUE, 0, 0, 0);
892 		evdev_support_abs(sc->sc_evdev, ABS_Y, 0,
893 		    ADC_MAX_VALUE, 0, 0, 0);
894 
895 		evdev_support_key(sc->sc_evdev, BTN_TOUCH);
896 
897 		err = evdev_register(sc->sc_evdev);
898 		if (err) {
899 			device_printf(dev,
900 			    "failed to register evdev: error=%d\n", err);
901 			ti_adc_detach(dev);
902 			return (err);
903 		}
904 
905 		sc->sc_pen_down = 0;
906 		sc->sc_x = -1;
907 		sc->sc_y = -1;
908 	}
909 #endif /* EVDEV */
910 
911 	return (0);
912 }
913 
914 static int
915 ti_adc_detach(device_t dev)
916 {
917 	struct ti_adc_softc *sc;
918 
919 	sc = device_get_softc(dev);
920 
921 	/* Turn off the ADC. */
922 	TI_ADC_LOCK(sc);
923 	ti_adc_reset(sc);
924 	ti_adc_setup(sc);
925 
926 #ifdef EVDEV_SUPPORT
927 	evdev_free(sc->sc_evdev);
928 #endif
929 
930 	TI_ADC_UNLOCK(sc);
931 
932 	TI_ADC_LOCK_DESTROY(sc);
933 
934 	if (sc->sc_intrhand)
935 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
936 	if (sc->sc_irq_res)
937 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
938 	if (sc->sc_mem_res)
939 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
940 
941 	return (bus_generic_detach(dev));
942 }
943 
944 static device_method_t ti_adc_methods[] = {
945 	DEVMETHOD(device_probe,		ti_adc_probe),
946 	DEVMETHOD(device_attach,	ti_adc_attach),
947 	DEVMETHOD(device_detach,	ti_adc_detach),
948 
949 	DEVMETHOD_END
950 };
951 
952 static driver_t ti_adc_driver = {
953 	"ti_adc",
954 	ti_adc_methods,
955 	sizeof(struct ti_adc_softc),
956 };
957 
958 DRIVER_MODULE(ti_adc, simplebus, ti_adc_driver, 0, 0);
959 MODULE_VERSION(ti_adc, 1);
960 MODULE_DEPEND(ti_adc, simplebus, 1, 1, 1);
961 MODULE_DEPEND(ti_adc, ti_sysc, 1, 1, 1);
962 #ifdef EVDEV_SUPPORT
963 MODULE_DEPEND(ti_adc, evdev, 1, 1, 1);
964 #endif
965