summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/tnetv107x-ts.c
blob: 22a3411e93c56bf7f8577334ab19d7a4e2003111 (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
/*
 * Texas Instruments TNETV107X Touchscreen Driver
 *
 * Copyright (C) 2010 Texas Instruments
 *
 * 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.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/ctype.h>
#include <linux/io.h>
#include <linux/clk.h>

#include <mach/tnetv107x.h>

#define TSC_PENUP_POLL		(HZ / 5)
#define IDLE_TIMEOUT		100 /* msec */

/*
 * The first and last samples of a touch interval are usually garbage and need
 * to be filtered out with these devices.  The following definitions control
 * the number of samples skipped.
 */
#define TSC_HEAD_SKIP		1
#define TSC_TAIL_SKIP		1
#define TSC_SKIP		(TSC_HEAD_SKIP + TSC_TAIL_SKIP + 1)
#define TSC_SAMPLES		(TSC_SKIP + 1)

/* Register Offsets */
struct tsc_regs {
	u32	rev;
	u32	tscm;
	u32	bwcm;
	u32	swc;
	u32	adcchnl;
	u32	adcdata;
	u32	chval[4];
};

/* TSC Mode Configuration Register (tscm) bits */
#define WMODE		BIT(0)
#define TSKIND		BIT(1)
#define ZMEASURE_EN	BIT(2)
#define IDLE		BIT(3)
#define TSC_EN		BIT(4)
#define STOP		BIT(5)
#define ONE_SHOT	BIT(6)
#define SINGLE		BIT(7)
#define AVG		BIT(8)
#define AVGNUM(x)	(((x) & 0x03) <<  9)
#define PVSTC(x)	(((x) & 0x07) << 11)
#define PON		BIT(14)
#define PONBG		BIT(15)
#define AFERST		BIT(16)

/* ADC DATA Capture Register bits */
#define DATA_VALID	BIT(16)

/* Register Access Macros */
#define tsc_read(ts, reg)		__raw_readl(&(ts)->regs->reg)
#define tsc_write(ts, reg, val)		__raw_writel(val, &(ts)->regs->reg);
#define tsc_set_bits(ts, reg, val)	\
	tsc_write(ts, reg, tsc_read(ts, reg) | (val))
#define tsc_clr_bits(ts, reg, val)	\
	tsc_write(ts, reg, tsc_read(ts, reg) & ~(val))

struct sample {
	int x, y, p;
};

struct tsc_data {
	struct input_dev		*input_dev;
	struct resource			*res;
	struct tsc_regs __iomem		*regs;
	struct timer_list		timer;
	spinlock_t			lock;
	struct clk			*clk;
	struct device			*dev;
	int				sample_count;
	struct sample			samples[TSC_SAMPLES];
	int				tsc_irq;
};

static int tsc_read_sample(struct tsc_data *ts, struct sample* sample)
{
	int	x, y, z1, z2, t, p = 0;
	u32	val;

	val = tsc_read(ts, chval[0]);
	if (val & DATA_VALID)
		x = val & 0xffff;
	else
		return -EINVAL;

	y  = tsc_read(ts, chval[1]) & 0xffff;
	z1 = tsc_read(ts, chval[2]) & 0xffff;
	z2 = tsc_read(ts, chval[3]) & 0xffff;

	if (z1) {
		t = ((600 * x) * (z2 - z1));
		p = t / (u32) (z1 << 12);
		if (p < 0)
			p = 0;
	}

	sample->x  = x;
	sample->y  = y;
	sample->p  = p;

	return 0;
}

static void tsc_poll(unsigned long data)
{
	struct tsc_data *ts = (struct tsc_data *)data;
	unsigned long flags;
	int i, val, x, y, p;

	spin_lock_irqsave(&ts->lock, flags);

	if (ts->sample_count >= TSC_SKIP) {
		input_report_abs(ts->input_dev, ABS_PRESSURE, 0);
		input_report_key(ts->input_dev, BTN_TOUCH, 0);
		input_sync(ts->input_dev);
	} else if (ts->sample_count > 0) {
		/*
		 * A touch event lasted less than our skip count.  Salvage and
		 * report anyway.
		 */
		for (i = 0, val = 0; i < ts->sample_count; i++)
			val += ts->samples[i].x;
		x = val / ts->sample_count;

		for (i = 0, val = 0; i < ts->sample_count; i++)
			val += ts->samples[i].y;
		y = val / ts->sample_count;

		for (i = 0, val = 0; i < ts->sample_count; i++)
			val += ts->samples[i].p;
		p = val / ts->sample_count;

		input_report_abs(ts->input_dev, ABS_X, x);
		input_report_abs(ts->input_dev, ABS_Y, y);
		input_report_abs(ts->input_dev, ABS_PRESSURE, p);
		input_report_key(ts->input_dev, BTN_TOUCH, 1);
		input_sync(ts->input_dev);
	}

	ts->sample_count = 0;

	spin_unlock_irqrestore(&ts->lock, flags);
}

static irqreturn_t tsc_irq(int irq, void *dev_id)
{
	struct tsc_data *ts = (struct tsc_data *)dev_id;
	struct sample *sample;
	int index;

	spin_lock(&ts->lock);

	index = ts->sample_count % TSC_SAMPLES;
	sample = &ts->samples[index];
	if (tsc_read_sample(ts, sample) < 0)
		goto out;

	if (++ts->sample_count >= TSC_SKIP) {
		index = (ts->sample_count - TSC_TAIL_SKIP - 1) % TSC_SAMPLES;
		sample = &ts->samples[index];

		input_report_abs(ts->input_dev, ABS_X, sample->x);
		input_report_abs(ts->input_dev, ABS_Y, sample->y);
		input_report_abs(ts->input_dev, ABS_PRESSURE, sample->p);
		if (ts->sample_count == TSC_SKIP)
			input_report_key(ts->input_dev, BTN_TOUCH, 1);
		input_sync(ts->input_dev);
	}
	mod_timer(&ts->timer, jiffies + TSC_PENUP_POLL);
out:
	spin_unlock(&ts->lock);
	return IRQ_HANDLED;
}

static int tsc_start(struct input_dev *dev)
{
	struct tsc_data *ts = input_get_drvdata(dev);
	unsigned long timeout = jiffies + msecs_to_jiffies(IDLE_TIMEOUT);
	u32 val;

	clk_enable(ts->clk);

	/* Go to idle mode, before any initialization */
	while (time_after(timeout, jiffies)) {
		if (tsc_read(ts, tscm) & IDLE)
			break;
	}

	if (time_before(timeout, jiffies)) {
		dev_warn(ts->dev, "timeout waiting for idle\n");
		clk_disable(ts->clk);
		return -EIO;
	}

	/* Configure TSC Control register*/
	val = (PONBG | PON | PVSTC(4) | ONE_SHOT | ZMEASURE_EN);
	tsc_write(ts, tscm, val);

	/* Bring TSC out of reset: Clear AFE reset bit */
	val &= ~(AFERST);
	tsc_write(ts, tscm, val);

	/* Configure all pins for hardware control*/
	tsc_write(ts, bwcm, 0);

	/* Finally enable the TSC */
	tsc_set_bits(ts, tscm, TSC_EN);

	return 0;
}

static void tsc_stop(struct input_dev *dev)
{
	struct tsc_data *ts = input_get_drvdata(dev);

	tsc_clr_bits(ts, tscm, TSC_EN);
	synchronize_irq(ts->tsc_irq);
	del_timer_sync(&ts->timer);
	clk_disable(ts->clk);
}

static int __devinit tsc_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct tsc_data *ts;
	int error = 0;
	u32 rev = 0;

	ts = kzalloc(sizeof(struct tsc_data), GFP_KERNEL);
	if (!ts) {
		dev_err(dev, "cannot allocate device info\n");
		return -ENOMEM;
	}

	ts->dev = dev;
	spin_lock_init(&ts->lock);
	setup_timer(&ts->timer, tsc_poll, (unsigned long)ts);
	platform_set_drvdata(pdev, ts);

	ts->tsc_irq = platform_get_irq(pdev, 0);
	if (ts->tsc_irq < 0) {
		dev_err(dev, "cannot determine device interrupt\n");
		error = -ENODEV;
		goto error_res;
	}

	ts->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!ts->res) {
		dev_err(dev, "cannot determine register area\n");
		error = -ENODEV;
		goto error_res;
	}

	if (!request_mem_region(ts->res->start, resource_size(ts->res),
				pdev->name)) {
		dev_err(dev, "cannot claim register memory\n");
		ts->res = NULL;
		error = -EINVAL;
		goto error_res;
	}

	ts->regs = ioremap(ts->res->start, resource_size(ts->res));
	if (!ts->regs) {
		dev_err(dev, "cannot map register memory\n");
		error = -ENOMEM;
		goto error_map;
	}

	ts->clk = clk_get(dev, NULL);
	if (IS_ERR(ts->clk)) {
		dev_err(dev, "cannot claim device clock\n");
		error = PTR_ERR(ts->clk);
		goto error_clk;
	}

	error = request_threaded_irq(ts->tsc_irq, NULL, tsc_irq, 0,
				     dev_name(dev), ts);
	if (error < 0) {
		dev_err(ts->dev, "Could not allocate ts irq\n");
		goto error_irq;
	}

	ts->input_dev = input_allocate_device();
	if (!ts->input_dev) {
		dev_err(dev, "cannot allocate input device\n");
		error = -ENOMEM;
		goto error_input;
	}
	input_set_drvdata(ts->input_dev, ts);

	ts->input_dev->name       = pdev->name;
	ts->input_dev->id.bustype = BUS_HOST;
	ts->input_dev->dev.parent = &pdev->dev;
	ts->input_dev->open	  = tsc_start;
	ts->input_dev->close	  = tsc_stop;

	clk_enable(ts->clk);
	rev = tsc_read(ts, rev);
	ts->input_dev->id.product = ((rev >>  8) & 0x07);
	ts->input_dev->id.version = ((rev >> 16) & 0xfff);
	clk_disable(ts->clk);

	__set_bit(EV_KEY,    ts->input_dev->evbit);
	__set_bit(EV_ABS,    ts->input_dev->evbit);
	__set_bit(BTN_TOUCH, ts->input_dev->keybit);

	input_set_abs_params(ts->input_dev, ABS_X, 0, 0xffff, 5, 0);
	input_set_abs_params(ts->input_dev, ABS_Y, 0, 0xffff, 5, 0);
	input_set_abs_params(ts->input_dev, ABS_PRESSURE, 0, 4095, 128, 0);

	error = input_register_device(ts->input_dev);
	if (error < 0) {
		dev_err(dev, "failed input device registration\n");
		goto error_reg;
	}

	return 0;

error_reg:
	input_free_device(ts->input_dev);
error_input:
	free_irq(ts->tsc_irq, ts);
error_irq:
	clk_put(ts->clk);
error_clk:
	iounmap(ts->regs);
error_map:
	release_mem_region(ts->res->start, resource_size(ts->res));
error_res:
	platform_set_drvdata(pdev, NULL);
	kfree(ts);

	return error;
}

static int __devexit tsc_remove(struct platform_device *pdev)
{
	struct tsc_data *ts = platform_get_drvdata(pdev);

	input_unregister_device(ts->input_dev);
	free_irq(ts->tsc_irq, ts);
	clk_put(ts->clk);
	iounmap(ts->regs);
	release_mem_region(ts->res->start, resource_size(ts->res));
	platform_set_drvdata(pdev, NULL);
	kfree(ts);

	return 0;
}

static struct platform_driver tsc_driver = {
	.probe		= tsc_probe,
	.remove		= __devexit_p(tsc_remove),
	.driver.name	= "tnetv107x-ts",
	.driver.owner	= THIS_MODULE,
};

static int __init tsc_init(void)
{
	return platform_driver_register(&tsc_driver);
}

static void __exit tsc_exit(void)
{
	platform_driver_unregister(&tsc_driver);
}

module_init(tsc_init);
module_exit(tsc_exit);

MODULE_AUTHOR("Cyril Chemparathy");
MODULE_DESCRIPTION("TNETV107X Touchscreen Driver");
MODULE_ALIAS("platform: tnetv107x-ts");
MODULE_LICENSE("GPL");