aboutsummaryrefslogtreecommitdiff
path: root/drivers/input/touchscreen/intel-mid-touch.c
blob: c0307b22d86fe78f9c74fdb27225b4971567232c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
/*
 * Intel MID Resistive Touch Screen Driver
 *
 * Copyright (C) 2008 Intel Corp
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * Questions/Comments/Bug fixes to Sreedhara (sreedhara.ds@intel.com)
 *			    Ramesh Agarwal (ramesh.agarwal@intel.com)
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * TODO:
 *	review conversion of r/m/w sequences
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/param.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <asm/intel_scu_ipc.h>

/* PMIC Interrupt registers */
#define PMIC_REG_ID1		0x00 /* PMIC ID1 register */

/* PMIC Interrupt registers */
#define PMIC_REG_INT		0x04 /* PMIC interrupt register */
#define PMIC_REG_MINT		0x05 /* PMIC interrupt mask register */

/* ADC Interrupt registers */
#define PMIC_REG_ADCINT		0x5F /* ADC interrupt register */
#define PMIC_REG_MADCINT	0x60 /* ADC interrupt mask register */

/* ADC Control registers */
#define PMIC_REG_ADCCNTL1	0x61 /* ADC control register */

/* ADC Channel Selection registers */
#define PMICADDR0		0xA4
#define END_OF_CHANNEL		0x1F

/* ADC Result register */
#define PMIC_REG_ADCSNS0H	0x64

/* ADC channels for touch screen */
#define MRST_TS_CHAN10		0xA /* Touch screen X+ connection */
#define MRST_TS_CHAN11		0xB /* Touch screen X- connection */
#define MRST_TS_CHAN12		0xC /* Touch screen Y+ connection */
#define MRST_TS_CHAN13		0xD /* Touch screen Y- connection */

/* Touch screen channel BIAS constants */
#define MRST_XBIAS		0x20
#define MRST_YBIAS		0x40
#define MRST_ZBIAS		0x80

/* Touch screen coordinates */
#define MRST_X_MIN		10
#define MRST_X_MAX		1024
#define MRST_X_FUZZ		5
#define MRST_Y_MIN		10
#define MRST_Y_MAX		1024
#define MRST_Y_FUZZ		5
#define MRST_PRESSURE_MIN	0
#define MRST_PRESSURE_NOMINAL	50
#define MRST_PRESSURE_MAX	100

#define WAIT_ADC_COMPLETION	10 /* msec */

/* PMIC ADC round robin delays */
#define ADC_LOOP_DELAY0		0x0 /* Continuous loop */
#define ADC_LOOP_DELAY1		0x1 /* 4.5  ms approximate */

/* PMIC Vendor Identifiers */
#define PMIC_VENDOR_FS		0 /* PMIC vendor FreeScale */
#define PMIC_VENDOR_MAXIM	1 /* PMIC vendor MAXIM */
#define PMIC_VENDOR_NEC		2 /* PMIC vendor NEC */
#define MRSTOUCH_MAX_CHANNELS	32 /* Maximum ADC channels */

/* Touch screen device structure */
struct mrstouch_dev {
	struct device *dev; /* device associated with touch screen */
	struct input_dev *input;
	char phys[32];
	u16 asr;		/* Address selection register */
	int irq;
	unsigned int vendor;	/* PMIC vendor */
	unsigned int rev;	/* PMIC revision */

	int (*read_prepare)(struct mrstouch_dev *tsdev);
	int (*read)(struct mrstouch_dev *tsdev, u16 *x, u16 *y, u16 *z);
	int (*read_finish)(struct mrstouch_dev *tsdev);
};


/*************************** NEC and Maxim Interface ************************/

static int mrstouch_nec_adc_read_prepare(struct mrstouch_dev *tsdev)
{
	return intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0, 0x20);
}

/*
 * Enables PENDET interrupt.
 */
static int mrstouch_nec_adc_read_finish(struct mrstouch_dev *tsdev)
{
	int err;

	err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0x20, 0x20);
	if (!err)
		err = intel_scu_ipc_update_register(PMIC_REG_ADCCNTL1, 0, 0x05);

	return err;
}

/*
 * Reads PMIC ADC touch screen result
 * Reads ADC storage registers for higher 7 and lower 3 bits and
 * converts the two readings into a single value and turns off gain bit
 */
static int mrstouch_ts_chan_read(u16 offset, u16 chan, u16 *vp, u16 *vm)
{
	int err;
	u16 result;
	u32 res;

	result = PMIC_REG_ADCSNS0H + offset;

	if (chan == MRST_TS_CHAN12)
		result += 4;

	err = intel_scu_ipc_ioread32(result, &res);
	if (err)
		return err;

	/* Mash the bits up */

	*vp = (res & 0xFF) << 3;	/* Highest 7 bits */
	*vp |= (res >> 8) & 0x07;	/* Lower 3 bits */
	*vp &= 0x3FF;

	res >>= 16;

	*vm = (res & 0xFF) << 3;	/* Highest 7 bits */
	*vm |= (res >> 8) & 0x07;	/* Lower 3 bits */
	*vm &= 0x3FF;

	return 0;
}

/*
 * Enables X, Y and Z bias values
 * Enables YPYM for X channels and XPXM for Y channels
 */
static int mrstouch_ts_bias_set(uint offset, uint bias)
{
	int count;
	u16 chan, start;
	u16 reg[4];
	u8 data[4];

	chan = PMICADDR0 + offset;
	start = MRST_TS_CHAN10;

	for (count = 0; count <= 3; count++) {
		reg[count] = chan++;
		data[count] = bias | (start + count);
	}

	return intel_scu_ipc_writev(reg, data, 4);
}

/* To read touch screen channel values */
static int mrstouch_nec_adc_read(struct mrstouch_dev *tsdev,
				 u16 *x, u16 *y, u16 *z)
{
	int err;
	u16 xm, ym, zm;

	/* configure Y bias for X channels */
	err = mrstouch_ts_bias_set(tsdev->asr, MRST_YBIAS);
	if (err)
		goto ipc_error;

	msleep(WAIT_ADC_COMPLETION);

	/* read x+ and x- channels */
	err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN10, x, &xm);
	if (err)
		goto ipc_error;

	/* configure x bias for y channels */
	err = mrstouch_ts_bias_set(tsdev->asr, MRST_XBIAS);
	if (err)
		goto ipc_error;

	msleep(WAIT_ADC_COMPLETION);

	/* read y+ and y- channels */
	err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN12, y, &ym);
	if (err)
		goto ipc_error;

	/* configure z bias for x and y channels */
	err = mrstouch_ts_bias_set(tsdev->asr, MRST_ZBIAS);
	if (err)
		goto ipc_error;

	msleep(WAIT_ADC_COMPLETION);

	/* read z+ and z- channels */
	err = mrstouch_ts_chan_read(tsdev->asr, MRST_TS_CHAN10, z, &zm);
	if (err)
		goto ipc_error;

	return 0;

ipc_error:
	dev_err(tsdev->dev, "ipc error during adc read\n");
	return err;
}


/*************************** Freescale Interface ************************/

static int mrstouch_fs_adc_read_prepare(struct mrstouch_dev *tsdev)
{
	int err, count;
	u16 chan;
	u16 reg[5];
	u8 data[5];

	/* Stop the ADC */
	err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0x00, 0x02);
	if (err)
		goto ipc_error;

	chan = PMICADDR0 + tsdev->asr;

	/* Set X BIAS */
	for (count = 0; count <= 3; count++) {
		reg[count] = chan++;
		data[count] = 0x2A;
	}
	reg[count] =  chan++; /* Dummy */
	data[count] = 0;

	err = intel_scu_ipc_writev(reg, data, 5);
	if (err)
		goto ipc_error;

	msleep(WAIT_ADC_COMPLETION);

	/* Set Y BIAS */
	for (count = 0; count <= 3; count++) {
		reg[count] = chan++;
		data[count] = 0x4A;
	}
	reg[count] = chan++; /* Dummy */
	data[count] = 0;

	err = intel_scu_ipc_writev(reg, data, 5);
	if (err)
		goto ipc_error;

	msleep(WAIT_ADC_COMPLETION);

	/* Set Z BIAS */
	err = intel_scu_ipc_iowrite32(chan + 2, 0x8A8A8A8A);
	if (err)
		goto ipc_error;

	msleep(WAIT_ADC_COMPLETION);

	return 0;

ipc_error:
	dev_err(tsdev->dev, "ipc error during %s\n", __func__);
	return err;
}

static int mrstouch_fs_adc_read(struct mrstouch_dev *tsdev,
				u16 *x, u16 *y, u16 *z)
{
	int err;
	u16 result;
	u16 reg[4];
	u8 data[4];

	result = PMIC_REG_ADCSNS0H + tsdev->asr;

	reg[0] = result + 4;
	reg[1] = result + 5;
	reg[2] = result + 16;
	reg[3] = result + 17;

	err = intel_scu_ipc_readv(reg, data, 4);
	if (err)
		goto ipc_error;

	*x = data[0] << 3; /* Higher 7 bits */
	*x |= data[1] & 0x7; /* Lower 3 bits */
	*x &= 0x3FF;

	*y = data[2] << 3; /* Higher 7 bits */
	*y |= data[3] & 0x7; /* Lower 3 bits */
	*y &= 0x3FF;

	/* Read Z value */
	reg[0] = result + 28;
	reg[1] = result + 29;

	err = intel_scu_ipc_readv(reg, data, 4);
	if (err)
		goto ipc_error;

	*z = data[0] << 3; /* Higher 7 bits */
	*z |= data[1] & 0x7; /* Lower 3 bits */
	*z &= 0x3FF;

	return 0;

ipc_error:
	dev_err(tsdev->dev, "ipc error during %s\n", __func__);
	return err;
}

static int mrstouch_fs_adc_read_finish(struct mrstouch_dev *tsdev)
{
	int err, count;
	u16 chan;
	u16 reg[5];
	u8 data[5];

	/* Clear all TS channels */
	chan = PMICADDR0 + tsdev->asr;
	for (count = 0; count <= 4; count++) {
		reg[count] = chan++;
		data[count] = 0;
	}
	err = intel_scu_ipc_writev(reg, data, 5);
	if (err)
		goto ipc_error;

	for (count = 0; count <= 4; count++) {
		reg[count] = chan++;
		data[count] = 0;
	}
	err = intel_scu_ipc_writev(reg, data, 5);
	if (err)
		goto ipc_error;

	err = intel_scu_ipc_iowrite32(chan + 2, 0x00000000);
	if (err)
		goto ipc_error;

	/* Start ADC */
	err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, 0x02, 0x02);
	if (err)
		goto ipc_error;

	return 0;

ipc_error:
	dev_err(tsdev->dev, "ipc error during %s\n", __func__);
	return err;
}

static void mrstouch_report_event(struct input_dev *input,
			unsigned int x, unsigned int y, unsigned int z)
{
	if (z > MRST_PRESSURE_NOMINAL) {
		/* Pen touched, report button touch and coordinates */
		input_report_key(input, BTN_TOUCH, 1);
		input_report_abs(input, ABS_X, x);
		input_report_abs(input, ABS_Y, y);
	} else {
		input_report_key(input, BTN_TOUCH, 0);
	}

	input_report_abs(input, ABS_PRESSURE, z);
	input_sync(input);
}

/* PENDET interrupt handler */
static irqreturn_t mrstouch_pendet_irq(int irq, void *dev_id)
{
	struct mrstouch_dev *tsdev = dev_id;
	u16 x, y, z;

	/*
	 * Should we lower thread priority? Probably not, since we are
	 * not spinning but sleeping...
	 */

	if (tsdev->read_prepare(tsdev))
		goto out;

	do {
		if (tsdev->read(tsdev, &x, &y, &z))
			break;

		mrstouch_report_event(tsdev->input, x, y, z);
	} while (z > MRST_PRESSURE_NOMINAL);

	tsdev->read_finish(tsdev);

out:
	return IRQ_HANDLED;
}

/* Utility to read PMIC ID */
static int __devinit mrstouch_read_pmic_id(uint *vendor, uint *rev)
{
	int err;
	u8 r;

	err = intel_scu_ipc_ioread8(PMIC_REG_ID1, &r);
	if (err)
		return err;

	*vendor = r & 0x7;
	*rev = (r >> 3) & 0x7;

	return 0;
}

/*
 * Parse ADC channels to find end of the channel configured by other ADC user
 * NEC and MAXIM requires 4 channels and FreeScale needs 18 channels
 */
static int __devinit mrstouch_chan_parse(struct mrstouch_dev *tsdev)
{
	int err, i, found;
	u8 r8;

	found = -1;

	for (i = 0; i < MRSTOUCH_MAX_CHANNELS; i++) {
		if (found >= 0)
			break;

		err = intel_scu_ipc_ioread8(PMICADDR0 + i, &r8);
		if (err)
			return err;

		if (r8 == END_OF_CHANNEL) {
			found = i;
			break;
		}
	}
	if (found < 0)
		return 0;

	if (tsdev->vendor == PMIC_VENDOR_FS) {
		if (found && found > (MRSTOUCH_MAX_CHANNELS - 18))
			return -ENOSPC;
	} else {
		if (found && found > (MRSTOUCH_MAX_CHANNELS - 4))
			return -ENOSPC;
	}
	return found;
}


/*
 * Writes touch screen channels to ADC address selection registers
 */
static int __devinit mrstouch_ts_chan_set(uint offset)
{
	u16 chan;

	int ret, count;

	chan = PMICADDR0 + offset;
	for (count = 0; count <= 3; count++) {
		ret = intel_scu_ipc_iowrite8(chan++, MRST_TS_CHAN10 + count);
		if (ret)
			return ret;
	}
	return intel_scu_ipc_iowrite8(chan++, END_OF_CHANNEL);
}

/* Initialize ADC */
static int __devinit mrstouch_adc_init(struct mrstouch_dev *tsdev)
{
	int err, start;
	u8 ra, rm;

	err = mrstouch_read_pmic_id(&tsdev->vendor, &tsdev->rev);
	if (err) {
		dev_err(tsdev->dev, "Unable to read PMIC id\n");
		return err;
	}

	switch (tsdev->vendor) {
	case PMIC_VENDOR_NEC:
	case PMIC_VENDOR_MAXIM:
		tsdev->read_prepare = mrstouch_nec_adc_read_prepare;
		tsdev->read = mrstouch_nec_adc_read;
		tsdev->read_finish = mrstouch_nec_adc_read_finish;
		break;

	case PMIC_VENDOR_FS:
		tsdev->read_prepare = mrstouch_fs_adc_read_prepare;
		tsdev->read = mrstouch_fs_adc_read;
		tsdev->read_finish = mrstouch_fs_adc_read_finish;
		break;

	default:
		dev_err(tsdev->dev,
			"Unsupported touchscreen: %d\n", tsdev->vendor);
		return -ENXIO;
	}

	start = mrstouch_chan_parse(tsdev);
	if (start < 0) {
		dev_err(tsdev->dev, "Unable to parse channels\n");
		return start;
	}

	tsdev->asr = start;

	/*
	 * ADC power on, start, enable PENDET and set loop delay
	 * ADC loop delay is set to 4.5 ms approximately
	 * Loop delay more than this results in jitter in adc readings
	 * Setting loop delay to 0 (continous loop) in MAXIM stops PENDET
	 * interrupt generation sometimes.
	 */

	if (tsdev->vendor == PMIC_VENDOR_FS) {
		ra = 0xE0 | ADC_LOOP_DELAY0;
		rm = 0x5;
	} else {
		/* NEC and MAXIm not consistent with loop delay 0 */
		ra = 0xE0 | ADC_LOOP_DELAY1;
		rm = 0x0;

		/* configure touch screen channels */
		err = mrstouch_ts_chan_set(tsdev->asr);
		if (err)
			return err;
	}

	err = intel_scu_ipc_update_register(PMIC_REG_ADCCNTL1, ra, 0xE7);
	if (err)
		return err;

	err = intel_scu_ipc_update_register(PMIC_REG_MADCINT, rm, 0x03);
	if (err)
		return err;

	return 0;
}


/* Probe function for touch screen driver */
static int __devinit mrstouch_probe(struct platform_device *pdev)
{
	struct mrstouch_dev *tsdev;
	struct input_dev *input;
	int err;
	int irq;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_err(&pdev->dev, "no interrupt assigned\n");
		return -EINVAL;
	}

	tsdev = kzalloc(sizeof(struct mrstouch_dev), GFP_KERNEL);
	input = input_allocate_device();
	if (!tsdev || !input) {
		dev_err(&pdev->dev, "unable to allocate memory\n");
		err = -ENOMEM;
		goto err_free_mem;
	}

	tsdev->dev = &pdev->dev;
	tsdev->input = input;
	tsdev->irq = irq;

	snprintf(tsdev->phys, sizeof(tsdev->phys),
		 "%s/input0", dev_name(tsdev->dev));

	err = mrstouch_adc_init(tsdev);
	if (err) {
		dev_err(&pdev->dev, "ADC initialization failed\n");
		goto err_free_mem;
	}

	input->name = "mrst_touchscreen";
	input->phys = tsdev->phys;
	input->dev.parent = tsdev->dev;

	input->id.vendor = tsdev->vendor;
	input->id.version = tsdev->rev;

	input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

	input_set_abs_params(tsdev->input, ABS_X,
			     MRST_X_MIN, MRST_X_MAX, MRST_X_FUZZ, 0);
	input_set_abs_params(tsdev->input, ABS_Y,
			     MRST_Y_MIN, MRST_Y_MAX, MRST_Y_FUZZ, 0);
	input_set_abs_params(tsdev->input, ABS_PRESSURE,
			     MRST_PRESSURE_MIN, MRST_PRESSURE_MAX, 0, 0);

	err = request_threaded_irq(tsdev->irq, NULL, mrstouch_pendet_irq,
				   0, "mrstouch", tsdev);
	if (err) {
		dev_err(tsdev->dev, "unable to allocate irq\n");
		goto err_free_mem;
	}

	err = input_register_device(tsdev->input);
	if (err) {
		dev_err(tsdev->dev, "unable to register input device\n");
		goto err_free_irq;
	}

	platform_set_drvdata(pdev, tsdev);
	return 0;

err_free_irq:
	free_irq(tsdev->irq, tsdev);
err_free_mem:
	input_free_device(input);
	kfree(tsdev);
	return err;
}

static int __devexit mrstouch_remove(struct platform_device *pdev)
{
	struct mrstouch_dev *tsdev = platform_get_drvdata(pdev);

	free_irq(tsdev->irq, tsdev);
	input_unregister_device(tsdev->input);
	kfree(tsdev);

	platform_set_drvdata(pdev, NULL);

	return 0;
}

static struct platform_driver mrstouch_driver = {
	.driver = {
		.name	= "pmic_touch",
		.owner	= THIS_MODULE,
	},
	.probe		= mrstouch_probe,
	.remove		= __devexit_p(mrstouch_remove),
};

static int __init mrstouch_init(void)
{
	return platform_driver_register(&mrstouch_driver);
}
module_init(mrstouch_init);

static void __exit mrstouch_exit(void)
{
	platform_driver_unregister(&mrstouch_driver);
}
module_exit(mrstouch_exit);

MODULE_AUTHOR("Sreedhara Murthy. D.S, sreedhara.ds@intel.com");
MODULE_DESCRIPTION("Intel Moorestown Resistive Touch Screen Driver");
MODULE_LICENSE("GPL");