aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/ucb1400_ts.c
blob: 6954f55001080d29b337a37c9398b6c8f867ec1a (plain) (blame)
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
/*
 *  Philips UCB1400 touchscreen driver
 *
 *  Author:	Nicolas Pitre
 *  Created:	September 25, 2006
 *  Copyright:	MontaVista Software, Inc.
 *
 * Spliting done by: Marek Vasut <marek.vasut@gmail.com>
 * If something doesnt work and it worked before spliting, e-mail me,
 * dont bother Nicolas please ;-)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
 * covering the UCB1100, UCB1200 and UCB1300..  Support for the UCB1400 has
 * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/ucb1400.h>

static int adcsync;
static int ts_delay = 55; /* us */
static int ts_delay_pressure;	/* us */

/* Switch to interrupt mode. */
static inline void ucb1400_ts_mode_int(struct snd_ac97 *ac97)
{
	ucb1400_reg_write(ac97, UCB_TS_CR,
			UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
			UCB_TS_CR_MODE_INT);
}

/*
 * Switch to pressure mode, and read pressure.  We don't need to wait
 * here, since both plates are being driven.
 */
static inline unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
{
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
			UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	udelay(ts_delay_pressure);
	return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
}

/*
 * Switch to X position mode and measure Y plate.  We switch the plate
 * configuration in pressure mode, then switch to position mode.  This
 * gives a faster response time.  Even so, we need to wait about 55us
 * for things to stabilise.
 */
static inline unsigned int ucb1400_ts_read_xpos(struct ucb1400_ts *ucb)
{
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
			UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);

	udelay(ts_delay);

	return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
}

/*
 * Switch to Y position mode and measure X plate.  We switch the plate
 * configuration in pressure mode, then switch to position mode.  This
 * gives a faster response time.  Even so, we need to wait about 55us
 * for things to stabilise.
 */
static inline unsigned int ucb1400_ts_read_ypos(struct ucb1400_ts *ucb)
{
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
			UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);

	udelay(ts_delay);

	return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPX, adcsync);
}

/*
 * Switch to X plate resistance mode.  Set MX to ground, PX to
 * supply.  Measure current.
 */
static inline unsigned int ucb1400_ts_read_xres(struct ucb1400_ts *ucb)
{
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	return ucb1400_adc_read(ucb->ac97, 0, adcsync);
}

/*
 * Switch to Y plate resistance mode.  Set MY to ground, PY to
 * supply.  Measure current.
 */
static inline unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
{
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	return ucb1400_adc_read(ucb->ac97, 0, adcsync);
}

static inline int ucb1400_ts_pen_down(struct snd_ac97 *ac97)
{
	unsigned short val = ucb1400_reg_read(ac97, UCB_TS_CR);
	return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
}

static inline void ucb1400_ts_irq_enable(struct snd_ac97 *ac97)
{
	ucb1400_reg_write(ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
	ucb1400_reg_write(ac97, UCB_IE_CLEAR, 0);
	ucb1400_reg_write(ac97, UCB_IE_FAL, UCB_IE_TSPX);
}

static inline void ucb1400_ts_irq_disable(struct snd_ac97 *ac97)
{
	ucb1400_reg_write(ac97, UCB_IE_FAL, 0);
}

static void ucb1400_ts_evt_add(struct input_dev *idev, u16 pressure, u16 x, u16 y)
{
	input_report_abs(idev, ABS_X, x);
	input_report_abs(idev, ABS_Y, y);
	input_report_abs(idev, ABS_PRESSURE, pressure);
	input_report_key(idev, BTN_TOUCH, 1);
	input_sync(idev);
}

static void ucb1400_ts_event_release(struct input_dev *idev)
{
	input_report_abs(idev, ABS_PRESSURE, 0);
	input_report_key(idev, BTN_TOUCH, 0);
	input_sync(idev);
}

static void ucb1400_handle_pending_irq(struct ucb1400_ts *ucb)
{
	unsigned int isr;

	isr = ucb1400_reg_read(ucb->ac97, UCB_IE_STATUS);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, isr);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);

	if (isr & UCB_IE_TSPX) {
		ucb1400_ts_irq_disable(ucb->ac97);
		enable_irq(ucb->irq);
	} else
		printk(KERN_ERR "ucb1400: unexpected IE_STATUS = %#x\n", isr);
}

static int ucb1400_ts_thread(void *_ucb)
{
	struct ucb1400_ts *ucb = _ucb;
	struct task_struct *tsk = current;
	int valid = 0;
	struct sched_param param = { .sched_priority = 1 };

	sched_setscheduler(tsk, SCHED_FIFO, &param);

	set_freezable();
	while (!kthread_should_stop()) {
		unsigned int x, y, p;
		long timeout;

		ucb->ts_restart = 0;

		if (ucb->irq_pending) {
			ucb->irq_pending = 0;
			ucb1400_handle_pending_irq(ucb);
		}

		ucb1400_adc_enable(ucb->ac97);
		x = ucb1400_ts_read_xpos(ucb);
		y = ucb1400_ts_read_ypos(ucb);
		p = ucb1400_ts_read_pressure(ucb);
		ucb1400_adc_disable(ucb->ac97);

		/* Switch back to interrupt mode. */
		ucb1400_ts_mode_int(ucb->ac97);

		msleep(10);

		if (ucb1400_ts_pen_down(ucb->ac97)) {
			ucb1400_ts_irq_enable(ucb->ac97);

			/*
			 * If we spat out a valid sample set last time,
			 * spit out a "pen off" sample here.
			 */
			if (valid) {
				ucb1400_ts_event_release(ucb->ts_idev);
				valid = 0;
			}

			timeout = MAX_SCHEDULE_TIMEOUT;
		} else {
			valid = 1;
			ucb1400_ts_evt_add(ucb->ts_idev, p, x, y);
			timeout = msecs_to_jiffies(10);
		}

		wait_event_freezable_timeout(ucb->ts_wait,
			ucb->irq_pending || ucb->ts_restart ||
			kthread_should_stop(), timeout);
	}

	/* Send the "pen off" if we are stopping with the pen still active */
	if (valid)
		ucb1400_ts_event_release(ucb->ts_idev);

	ucb->ts_task = NULL;
	return 0;
}

/*
 * A restriction with interrupts exists when using the ucb1400, as
 * the codec read/write routines may sleep while waiting for codec
 * access completion and uses semaphores for access control to the
 * AC97 bus.  A complete codec read cycle could take  anywhere from
 * 60 to 100uSec so we *definitely* don't want to spin inside the
 * interrupt handler waiting for codec access.  So, we handle the
 * interrupt by scheduling a RT kernel thread to run in process
 * context instead of interrupt context.
 */
static irqreturn_t ucb1400_hard_irq(int irqnr, void *devid)
{
	struct ucb1400_ts *ucb = devid;

	if (irqnr == ucb->irq) {
		disable_irq_nosync(ucb->irq);
		ucb->irq_pending = 1;
		wake_up(&ucb->ts_wait);
		return IRQ_HANDLED;
	}
	return IRQ_NONE;
}

static int ucb1400_ts_open(struct input_dev *idev)
{
	struct ucb1400_ts *ucb = input_get_drvdata(idev);
	int ret = 0;

	BUG_ON(ucb->ts_task);

	ucb->ts_task = kthread_run(ucb1400_ts_thread, ucb, "UCB1400_ts");
	if (IS_ERR(ucb->ts_task)) {
		ret = PTR_ERR(ucb->ts_task);
		ucb->ts_task = NULL;
	}

	return ret;
}

static void ucb1400_ts_close(struct input_dev *idev)
{
	struct ucb1400_ts *ucb = input_get_drvdata(idev);

	if (ucb->ts_task)
		kthread_stop(ucb->ts_task);

	ucb1400_ts_irq_disable(ucb->ac97);
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
}

#ifndef NO_IRQ
#define NO_IRQ	0
#endif

/*
 * Try to probe our interrupt, rather than relying on lots of
 * hard-coded machine dependencies.
 */
static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb)
{
	unsigned long mask, timeout;

	mask = probe_irq_on();

	/* Enable the ADC interrupt. */
	ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, UCB_IE_ADC);
	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_ADC);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);

	/* Cause an ADC interrupt. */
	ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA);
	ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);

	/* Wait for the conversion to complete. */
	timeout = jiffies + HZ/2;
	while (!(ucb1400_reg_read(ucb->ac97, UCB_ADC_DATA) &
						UCB_ADC_DAT_VALID)) {
		cpu_relax();
		if (time_after(jiffies, timeout)) {
			printk(KERN_ERR "ucb1400: timed out in IRQ probe\n");
			probe_irq_off(mask);
			return -ENODEV;
		}
	}
	ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, 0);

	/* Disable and clear interrupt. */
	ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, 0);
	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);

	/* Read triggered interrupt. */
	ucb->irq = probe_irq_off(mask);
	if (ucb->irq < 0 || ucb->irq == NO_IRQ)
		return -ENODEV;

	return 0;
}

static int ucb1400_ts_probe(struct platform_device *dev)
{
	int error, x_res, y_res;
	struct ucb1400_ts *ucb = dev->dev.platform_data;

	ucb->ts_idev = input_allocate_device();
	if (!ucb->ts_idev) {
		error = -ENOMEM;
		goto err;
	}

	error = ucb1400_ts_detect_irq(ucb);
	if (error) {
		printk(KERN_ERR "UCB1400: IRQ probe failed\n");
		goto err_free_devs;
	}

	init_waitqueue_head(&ucb->ts_wait);

	error = request_irq(ucb->irq, ucb1400_hard_irq, IRQF_TRIGGER_RISING,
				"UCB1400", ucb);
	if (error) {
		printk(KERN_ERR "ucb1400: unable to grab irq%d: %d\n",
				ucb->irq, error);
		goto err_free_devs;
	}
	printk(KERN_DEBUG "UCB1400: found IRQ %d\n", ucb->irq);

	input_set_drvdata(ucb->ts_idev, ucb);

	ucb->ts_idev->dev.parent	= &dev->dev;
	ucb->ts_idev->name		= "UCB1400 touchscreen interface";
	ucb->ts_idev->id.vendor		= ucb1400_reg_read(ucb->ac97,
						AC97_VENDOR_ID1);
	ucb->ts_idev->id.product	= ucb->id;
	ucb->ts_idev->open		= ucb1400_ts_open;
	ucb->ts_idev->close		= ucb1400_ts_close;
	ucb->ts_idev->evbit[0]		= BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
	ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

	ucb1400_adc_enable(ucb->ac97);
	x_res = ucb1400_ts_read_xres(ucb);
	y_res = ucb1400_ts_read_yres(ucb);
	ucb1400_adc_disable(ucb->ac97);
	printk(KERN_DEBUG "UCB1400: x/y = %d/%d\n", x_res, y_res);

	input_set_abs_params(ucb->ts_idev, ABS_X, 0, x_res, 0, 0);
	input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);
	input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);

	error = input_register_device(ucb->ts_idev);
	if (error)
		goto err_free_irq;

	return 0;

err_free_irq:
	free_irq(ucb->irq, ucb);
err_free_devs:
	input_free_device(ucb->ts_idev);
err:
	return error;

}

static int ucb1400_ts_remove(struct platform_device *dev)
{
	struct ucb1400_ts *ucb = dev->dev.platform_data;

	free_irq(ucb->irq, ucb);
	input_unregister_device(ucb->ts_idev);
	return 0;
}

#ifdef CONFIG_PM
static int ucb1400_ts_resume(struct platform_device *dev)
{
	struct ucb1400_ts *ucb = dev->dev.platform_data;

	if (ucb->ts_task) {
		/*
		 * Restart the TS thread to ensure the
		 * TS interrupt mode is set up again
		 * after sleep.
		 */
		ucb->ts_restart = 1;
		wake_up(&ucb->ts_wait);
	}
	return 0;
}
#else
#define ucb1400_ts_resume NULL
#endif

static struct platform_driver ucb1400_ts_driver = {
	.probe	= ucb1400_ts_probe,
	.remove	= ucb1400_ts_remove,
	.resume	= ucb1400_ts_resume,
	.driver	= {
		.name	= "ucb1400_ts",
	},
};

static int __init ucb1400_ts_init(void)
{
	return platform_driver_register(&ucb1400_ts_driver);
}

static void __exit ucb1400_ts_exit(void)
{
	platform_driver_unregister(&ucb1400_ts_driver);
}

module_param(adcsync, bool, 0444);
MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");

module_param(ts_delay, int, 0444);
MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
			    " position read. Default = 55us.");

module_param(ts_delay_pressure, int, 0444);
MODULE_PARM_DESC(ts_delay_pressure,
		"delay between panel setup and pressure read."
		"  Default = 0us.");

module_init(ucb1400_ts_init);
module_exit(ucb1400_ts_exit);

MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
MODULE_LICENSE("GPL");