summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/imx6ul_tsc.c
blob: c10fc594f94d9b6ad86b9faf32c8be9b63b2474c (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
// SPDX-License-Identifier: GPL-2.0
//
// Freescale i.MX6UL touchscreen controller driver
//
// Copyright (C) 2015 Freescale Semiconductor, Inc.

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gpio/consumer.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/log2.h>

/* ADC configuration registers field define */
#define ADC_AIEN		(0x1 << 7)
#define ADC_CONV_DISABLE	0x1F
#define ADC_AVGE		(0x1 << 5)
#define ADC_CAL			(0x1 << 7)
#define ADC_CALF		0x2
#define ADC_12BIT_MODE		(0x2 << 2)
#define ADC_CONV_MODE_MASK	(0x3 << 2)
#define ADC_IPG_CLK		0x00
#define ADC_INPUT_CLK_MASK	0x3
#define ADC_CLK_DIV_8		(0x03 << 5)
#define ADC_CLK_DIV_MASK	(0x3 << 5)
#define ADC_SHORT_SAMPLE_MODE	(0x0 << 4)
#define ADC_SAMPLE_MODE_MASK	(0x1 << 4)
#define ADC_HARDWARE_TRIGGER	(0x1 << 13)
#define ADC_AVGS_SHIFT		14
#define ADC_AVGS_MASK		(0x3 << 14)
#define SELECT_CHANNEL_4	0x04
#define SELECT_CHANNEL_1	0x01
#define DISABLE_CONVERSION_INT	(0x0 << 7)

/* ADC registers */
#define REG_ADC_HC0		0x00
#define REG_ADC_HC1		0x04
#define REG_ADC_HC2		0x08
#define REG_ADC_HC3		0x0C
#define REG_ADC_HC4		0x10
#define REG_ADC_HS		0x14
#define REG_ADC_R0		0x18
#define REG_ADC_CFG		0x2C
#define REG_ADC_GC		0x30
#define REG_ADC_GS		0x34

#define ADC_TIMEOUT		msecs_to_jiffies(100)

/* TSC registers */
#define REG_TSC_BASIC_SETING	0x00
#define REG_TSC_PRE_CHARGE_TIME	0x10
#define REG_TSC_FLOW_CONTROL	0x20
#define REG_TSC_MEASURE_VALUE	0x30
#define REG_TSC_INT_EN		0x40
#define REG_TSC_INT_SIG_EN	0x50
#define REG_TSC_INT_STATUS	0x60
#define REG_TSC_DEBUG_MODE	0x70
#define REG_TSC_DEBUG_MODE2	0x80

/* TSC configuration registers field define */
#define DETECT_4_WIRE_MODE	(0x0 << 4)
#define AUTO_MEASURE		0x1
#define MEASURE_SIGNAL		0x1
#define DETECT_SIGNAL		(0x1 << 4)
#define VALID_SIGNAL		(0x1 << 8)
#define MEASURE_INT_EN		0x1
#define MEASURE_SIG_EN		0x1
#define VALID_SIG_EN		(0x1 << 8)
#define DE_GLITCH_2		(0x2 << 29)
#define START_SENSE		(0x1 << 12)
#define TSC_DISABLE		(0x1 << 16)
#define DETECT_MODE		0x2

struct imx6ul_tsc {
	struct device *dev;
	struct input_dev *input;
	void __iomem *tsc_regs;
	void __iomem *adc_regs;
	struct clk *tsc_clk;
	struct clk *adc_clk;
	struct gpio_desc *xnur_gpio;

	u32 measure_delay_time;
	u32 pre_charge_time;
	bool average_enable;
	u32 average_select;

	struct completion completion;
};

/*
 * TSC module need ADC to get the measure value. So
 * before config TSC, we should initialize ADC module.
 */
static int imx6ul_adc_init(struct imx6ul_tsc *tsc)
{
	u32 adc_hc = 0;
	u32 adc_gc;
	u32 adc_gs;
	u32 adc_cfg;
	unsigned long timeout;

	reinit_completion(&tsc->completion);

	adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
	adc_cfg &= ~(ADC_CONV_MODE_MASK | ADC_INPUT_CLK_MASK);
	adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
	adc_cfg &= ~(ADC_CLK_DIV_MASK | ADC_SAMPLE_MODE_MASK);
	adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
	if (tsc->average_enable) {
		adc_cfg &= ~ADC_AVGS_MASK;
		adc_cfg |= (tsc->average_select) << ADC_AVGS_SHIFT;
	}
	adc_cfg &= ~ADC_HARDWARE_TRIGGER;
	writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);

	/* enable calibration interrupt */
	adc_hc |= ADC_AIEN;
	adc_hc |= ADC_CONV_DISABLE;
	writel(adc_hc, tsc->adc_regs + REG_ADC_HC0);

	/* start ADC calibration */
	adc_gc = readl(tsc->adc_regs + REG_ADC_GC);
	adc_gc |= ADC_CAL;
	if (tsc->average_enable)
		adc_gc |= ADC_AVGE;
	writel(adc_gc, tsc->adc_regs + REG_ADC_GC);

	timeout = wait_for_completion_timeout
			(&tsc->completion, ADC_TIMEOUT);
	if (timeout == 0) {
		dev_err(tsc->dev, "Timeout for adc calibration\n");
		return -ETIMEDOUT;
	}

	adc_gs = readl(tsc->adc_regs + REG_ADC_GS);
	if (adc_gs & ADC_CALF) {
		dev_err(tsc->dev, "ADC calibration failed\n");
		return -EINVAL;
	}

	/* TSC need the ADC work in hardware trigger */
	adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
	adc_cfg |= ADC_HARDWARE_TRIGGER;
	writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);

	return 0;
}

/*
 * This is a TSC workaround. Currently TSC misconnect two
 * ADC channels, this function remap channel configure for
 * hardware trigger.
 */
static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc)
{
	u32 adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4;

	adc_hc0 = DISABLE_CONVERSION_INT;
	writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0);

	adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4;
	writel(adc_hc1, tsc->adc_regs + REG_ADC_HC1);

	adc_hc2 = DISABLE_CONVERSION_INT;
	writel(adc_hc2, tsc->adc_regs + REG_ADC_HC2);

	adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1;
	writel(adc_hc3, tsc->adc_regs + REG_ADC_HC3);

	adc_hc4 = DISABLE_CONVERSION_INT;
	writel(adc_hc4, tsc->adc_regs + REG_ADC_HC4);
}

/*
 * TSC setting, confige the pre-charge time and measure delay time.
 * different touch screen may need different pre-charge time and
 * measure delay time.
 */
static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
{
	u32 basic_setting = 0;
	u32 start;

	basic_setting |= tsc->measure_delay_time << 8;
	basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
	writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETING);

	writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2);

	writel(tsc->pre_charge_time, tsc->tsc_regs + REG_TSC_PRE_CHARGE_TIME);
	writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN);
	writel(MEASURE_SIG_EN | VALID_SIG_EN,
		tsc->tsc_regs + REG_TSC_INT_SIG_EN);

	/* start sense detection */
	start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
	start |= START_SENSE;
	start &= ~TSC_DISABLE;
	writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
}

static int imx6ul_tsc_init(struct imx6ul_tsc *tsc)
{
	int err;

	err = imx6ul_adc_init(tsc);
	if (err)
		return err;
	imx6ul_tsc_channel_config(tsc);
	imx6ul_tsc_set(tsc);

	return 0;
}

static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc)
{
	u32 tsc_flow;
	u32 adc_cfg;

	/* TSC controller enters to idle status */
	tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
	tsc_flow |= TSC_DISABLE;
	writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);

	/* ADC controller enters to stop mode */
	adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0);
	adc_cfg |= ADC_CONV_DISABLE;
	writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0);
}

/* Delay some time (max 2ms), wait the pre-charge done. */
static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc)
{
	unsigned long timeout = jiffies + msecs_to_jiffies(2);
	u32 state_machine;
	u32 debug_mode2;

	do {
		if (time_after(jiffies, timeout))
			return false;

		usleep_range(200, 400);
		debug_mode2 = readl(tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
		state_machine = (debug_mode2 >> 20) & 0x7;
	} while (state_machine != DETECT_MODE);

	usleep_range(200, 400);
	return true;
}

static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
{
	struct imx6ul_tsc *tsc = dev_id;
	u32 status;
	u32 value;
	u32 x, y;
	u32 start;

	status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS);

	/* write 1 to clear the bit measure-signal */
	writel(MEASURE_SIGNAL | DETECT_SIGNAL,
		tsc->tsc_regs + REG_TSC_INT_STATUS);

	/* It's a HW self-clean bit. Set this bit and start sense detection */
	start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
	start |= START_SENSE;
	writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);

	if (status & MEASURE_SIGNAL) {
		value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE);
		x = (value >> 16) & 0x0fff;
		y = value & 0x0fff;

		/*
		 * In detect mode, we can get the xnur gpio value,
		 * otherwise assume contact is stiull active.
		 */
		if (!tsc_wait_detect_mode(tsc) ||
		    gpiod_get_value_cansleep(tsc->xnur_gpio)) {
			input_report_key(tsc->input, BTN_TOUCH, 1);
			input_report_abs(tsc->input, ABS_X, x);
			input_report_abs(tsc->input, ABS_Y, y);
		} else {
			input_report_key(tsc->input, BTN_TOUCH, 0);
		}

		input_sync(tsc->input);
	}

	return IRQ_HANDLED;
}

static irqreturn_t adc_irq_fn(int irq, void *dev_id)
{
	struct imx6ul_tsc *tsc = dev_id;
	u32 coco;
	u32 value;

	coco = readl(tsc->adc_regs + REG_ADC_HS);
	if (coco & 0x01) {
		value = readl(tsc->adc_regs + REG_ADC_R0);
		complete(&tsc->completion);
	}

	return IRQ_HANDLED;
}

static int imx6ul_tsc_open(struct input_dev *input_dev)
{
	struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
	int err;

	err = clk_prepare_enable(tsc->adc_clk);
	if (err) {
		dev_err(tsc->dev,
			"Could not prepare or enable the adc clock: %d\n",
			err);
		return err;
	}

	err = clk_prepare_enable(tsc->tsc_clk);
	if (err) {
		dev_err(tsc->dev,
			"Could not prepare or enable the tsc clock: %d\n",
			err);
		goto disable_adc_clk;
	}

	err = imx6ul_tsc_init(tsc);
	if (err)
		goto disable_tsc_clk;

	return 0;

disable_tsc_clk:
	clk_disable_unprepare(tsc->tsc_clk);
disable_adc_clk:
	clk_disable_unprepare(tsc->adc_clk);
	return err;
}

static void imx6ul_tsc_close(struct input_dev *input_dev)
{
	struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);

	imx6ul_tsc_disable(tsc);

	clk_disable_unprepare(tsc->tsc_clk);
	clk_disable_unprepare(tsc->adc_clk);
}

static int imx6ul_tsc_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct imx6ul_tsc *tsc;
	struct input_dev *input_dev;
	struct resource *tsc_mem;
	struct resource *adc_mem;
	int err;
	int tsc_irq;
	int adc_irq;
	u32 average_samples;

	tsc = devm_kzalloc(&pdev->dev, sizeof(*tsc), GFP_KERNEL);
	if (!tsc)
		return -ENOMEM;

	input_dev = devm_input_allocate_device(&pdev->dev);
	if (!input_dev)
		return -ENOMEM;

	input_dev->name = "iMX6UL Touchscreen Controller";
	input_dev->id.bustype = BUS_HOST;

	input_dev->open = imx6ul_tsc_open;
	input_dev->close = imx6ul_tsc_close;

	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
	input_set_abs_params(input_dev, ABS_X, 0, 0xFFF, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, 0xFFF, 0, 0);

	input_set_drvdata(input_dev, tsc);

	tsc->dev = &pdev->dev;
	tsc->input = input_dev;
	init_completion(&tsc->completion);

	tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur", GPIOD_IN);
	if (IS_ERR(tsc->xnur_gpio)) {
		err = PTR_ERR(tsc->xnur_gpio);
		dev_err(&pdev->dev,
			"failed to request GPIO tsc_X- (xnur): %d\n", err);
		return err;
	}

	tsc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	tsc->tsc_regs = devm_ioremap_resource(&pdev->dev, tsc_mem);
	if (IS_ERR(tsc->tsc_regs)) {
		err = PTR_ERR(tsc->tsc_regs);
		dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err);
		return err;
	}

	adc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	tsc->adc_regs = devm_ioremap_resource(&pdev->dev, adc_mem);
	if (IS_ERR(tsc->adc_regs)) {
		err = PTR_ERR(tsc->adc_regs);
		dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err);
		return err;
	}

	tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc");
	if (IS_ERR(tsc->tsc_clk)) {
		err = PTR_ERR(tsc->tsc_clk);
		dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err);
		return err;
	}

	tsc->adc_clk = devm_clk_get(&pdev->dev, "adc");
	if (IS_ERR(tsc->adc_clk)) {
		err = PTR_ERR(tsc->adc_clk);
		dev_err(&pdev->dev, "failed getting adc clock: %d\n", err);
		return err;
	}

	tsc_irq = platform_get_irq(pdev, 0);
	if (tsc_irq < 0) {
		dev_err(&pdev->dev, "no tsc irq resource?\n");
		return tsc_irq;
	}

	adc_irq = platform_get_irq(pdev, 1);
	if (adc_irq < 0) {
		dev_err(&pdev->dev, "no adc irq resource?\n");
		return adc_irq;
	}

	err = devm_request_threaded_irq(tsc->dev, tsc_irq,
					NULL, tsc_irq_fn, IRQF_ONESHOT,
					dev_name(&pdev->dev), tsc);
	if (err) {
		dev_err(&pdev->dev,
			"failed requesting tsc irq %d: %d\n",
			tsc_irq, err);
		return err;
	}

	err = devm_request_irq(tsc->dev, adc_irq, adc_irq_fn, 0,
				dev_name(&pdev->dev), tsc);
	if (err) {
		dev_err(&pdev->dev,
			"failed requesting adc irq %d: %d\n",
			adc_irq, err);
		return err;
	}

	err = of_property_read_u32(np, "measure-delay-time",
				   &tsc->measure_delay_time);
	if (err)
		tsc->measure_delay_time = 0xffff;

	err = of_property_read_u32(np, "pre-charge-time",
				   &tsc->pre_charge_time);
	if (err)
		tsc->pre_charge_time = 0xfff;

	err = of_property_read_u32(np, "touchscreen-average-samples",
				   &average_samples);
	if (err)
		average_samples = 1;

	switch (average_samples) {
	case 1:
		tsc->average_enable = false;
		tsc->average_select = 0; /* value unused; initialize anyway */
		break;
	case 4:
	case 8:
	case 16:
	case 32:
		tsc->average_enable = true;
		tsc->average_select = ilog2(average_samples) - 2;
		break;
	default:
		dev_err(&pdev->dev,
			"touchscreen-average-samples (%u) must be 1, 4, 8, 16 or 32\n",
			average_samples);
		return -EINVAL;
	}

	err = input_register_device(tsc->input);
	if (err) {
		dev_err(&pdev->dev,
			"failed to register input device: %d\n", err);
		return err;
	}

	platform_set_drvdata(pdev, tsc);
	return 0;
}

static int __maybe_unused imx6ul_tsc_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
	struct input_dev *input_dev = tsc->input;

	mutex_lock(&input_dev->mutex);

	if (input_dev->users) {
		imx6ul_tsc_disable(tsc);

		clk_disable_unprepare(tsc->tsc_clk);
		clk_disable_unprepare(tsc->adc_clk);
	}

	mutex_unlock(&input_dev->mutex);

	return 0;
}

static int __maybe_unused imx6ul_tsc_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
	struct input_dev *input_dev = tsc->input;
	int retval = 0;

	mutex_lock(&input_dev->mutex);

	if (input_dev->users) {
		retval = clk_prepare_enable(tsc->adc_clk);
		if (retval)
			goto out;

		retval = clk_prepare_enable(tsc->tsc_clk);
		if (retval) {
			clk_disable_unprepare(tsc->adc_clk);
			goto out;
		}

		retval = imx6ul_tsc_init(tsc);
	}

out:
	mutex_unlock(&input_dev->mutex);
	return retval;
}

static SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops,
			 imx6ul_tsc_suspend, imx6ul_tsc_resume);

static const struct of_device_id imx6ul_tsc_match[] = {
	{ .compatible = "fsl,imx6ul-tsc", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx6ul_tsc_match);

static struct platform_driver imx6ul_tsc_driver = {
	.driver		= {
		.name	= "imx6ul-tsc",
		.of_match_table	= imx6ul_tsc_match,
		.pm	= &imx6ul_tsc_pm_ops,
	},
	.probe		= imx6ul_tsc_probe,
};
module_platform_driver(imx6ul_tsc_driver);

MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>");
MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller driver");
MODULE_LICENSE("GPL v2");