Loading...
Note: File does not exist in v3.1.
1/*
2 * TSC2004/TSC2005 touchscreen driver core
3 *
4 * Copyright (C) 2006-2010 Nokia Corporation
5 * Copyright (C) 2015 QWERTY Embedded Design
6 * Copyright (C) 2015 EMAC Inc.
7 *
8 * Author: Lauri Leukkunen <lauri.leukkunen@nokia.com>
9 * based on TSC2301 driver by Klaus K. Pedersen <klaus.k.pedersen@nokia.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/input.h>
25#include <linux/input/touchscreen.h>
26#include <linux/interrupt.h>
27#include <linux/delay.h>
28#include <linux/pm.h>
29#include <linux/of.h>
30#include <linux/regulator/consumer.h>
31#include <linux/regmap.h>
32#include <linux/gpio/consumer.h>
33#include "tsc200x-core.h"
34
35/*
36 * The touchscreen interface operates as follows:
37 *
38 * 1) Pen is pressed against the touchscreen.
39 * 2) TSC200X performs AD conversion.
40 * 3) After the conversion is done TSC200X drives DAV line down.
41 * 4) GPIO IRQ is received and tsc200x_irq_thread() is scheduled.
42 * 5) tsc200x_irq_thread() queues up a transfer to fetch the x, y, z1, z2
43 * values.
44 * 6) tsc200x_irq_thread() reports coordinates to input layer and sets up
45 * tsc200x_penup_timer() to be called after TSC200X_PENUP_TIME_MS (40ms).
46 * 7) When the penup timer expires, there have not been touch or DAV interrupts
47 * during the last 40ms which means the pen has been lifted.
48 *
49 * ESD recovery via a hardware reset is done if the TSC200X doesn't respond
50 * after a configurable period (in ms) of activity. If esd_timeout is 0, the
51 * watchdog is disabled.
52 */
53
54static const struct regmap_range tsc200x_writable_ranges[] = {
55 regmap_reg_range(TSC200X_REG_AUX_HIGH, TSC200X_REG_CFR2),
56};
57
58static const struct regmap_access_table tsc200x_writable_table = {
59 .yes_ranges = tsc200x_writable_ranges,
60 .n_yes_ranges = ARRAY_SIZE(tsc200x_writable_ranges),
61};
62
63const struct regmap_config tsc200x_regmap_config = {
64 .reg_bits = 8,
65 .val_bits = 16,
66 .reg_stride = 0x08,
67 .max_register = 0x78,
68 .read_flag_mask = TSC200X_REG_READ,
69 .write_flag_mask = TSC200X_REG_PND0,
70 .wr_table = &tsc200x_writable_table,
71 .use_single_rw = true,
72};
73EXPORT_SYMBOL_GPL(tsc200x_regmap_config);
74
75struct tsc200x_data {
76 u16 x;
77 u16 y;
78 u16 z1;
79 u16 z2;
80} __packed;
81#define TSC200X_DATA_REGS 4
82
83struct tsc200x {
84 struct device *dev;
85 struct regmap *regmap;
86 __u16 bustype;
87
88 struct input_dev *idev;
89 char phys[32];
90
91 struct mutex mutex;
92
93 /* raw copy of previous x,y,z */
94 int in_x;
95 int in_y;
96 int in_z1;
97 int in_z2;
98
99 spinlock_t lock;
100 struct timer_list penup_timer;
101
102 unsigned int esd_timeout;
103 struct delayed_work esd_work;
104 unsigned long last_valid_interrupt;
105
106 unsigned int x_plate_ohm;
107
108 bool opened;
109 bool suspended;
110
111 bool pen_down;
112
113 struct regulator *vio;
114
115 struct gpio_desc *reset_gpio;
116 int (*tsc200x_cmd)(struct device *dev, u8 cmd);
117 int irq;
118};
119
120static void tsc200x_update_pen_state(struct tsc200x *ts,
121 int x, int y, int pressure)
122{
123 if (pressure) {
124 input_report_abs(ts->idev, ABS_X, x);
125 input_report_abs(ts->idev, ABS_Y, y);
126 input_report_abs(ts->idev, ABS_PRESSURE, pressure);
127 if (!ts->pen_down) {
128 input_report_key(ts->idev, BTN_TOUCH, !!pressure);
129 ts->pen_down = true;
130 }
131 } else {
132 input_report_abs(ts->idev, ABS_PRESSURE, 0);
133 if (ts->pen_down) {
134 input_report_key(ts->idev, BTN_TOUCH, 0);
135 ts->pen_down = false;
136 }
137 }
138 input_sync(ts->idev);
139 dev_dbg(ts->dev, "point(%4d,%4d), pressure (%4d)\n", x, y,
140 pressure);
141}
142
143static irqreturn_t tsc200x_irq_thread(int irq, void *_ts)
144{
145 struct tsc200x *ts = _ts;
146 unsigned long flags;
147 unsigned int pressure;
148 struct tsc200x_data tsdata;
149 int error;
150
151 /* read the coordinates */
152 error = regmap_bulk_read(ts->regmap, TSC200X_REG_X, &tsdata,
153 TSC200X_DATA_REGS);
154 if (unlikely(error))
155 goto out;
156
157 /* validate position */
158 if (unlikely(tsdata.x > MAX_12BIT || tsdata.y > MAX_12BIT))
159 goto out;
160
161 /* Skip reading if the pressure components are out of range */
162 if (unlikely(tsdata.z1 == 0 || tsdata.z2 > MAX_12BIT))
163 goto out;
164 if (unlikely(tsdata.z1 >= tsdata.z2))
165 goto out;
166
167 /*
168 * Skip point if this is a pen down with the exact same values as
169 * the value before pen-up - that implies SPI fed us stale data
170 */
171 if (!ts->pen_down &&
172 ts->in_x == tsdata.x && ts->in_y == tsdata.y &&
173 ts->in_z1 == tsdata.z1 && ts->in_z2 == tsdata.z2) {
174 goto out;
175 }
176
177 /*
178 * At this point we are happy we have a valid and useful reading.
179 * Remember it for later comparisons. We may now begin downsampling.
180 */
181 ts->in_x = tsdata.x;
182 ts->in_y = tsdata.y;
183 ts->in_z1 = tsdata.z1;
184 ts->in_z2 = tsdata.z2;
185
186 /* Compute touch pressure resistance using equation #1 */
187 pressure = tsdata.x * (tsdata.z2 - tsdata.z1) / tsdata.z1;
188 pressure = pressure * ts->x_plate_ohm / 4096;
189 if (unlikely(pressure > MAX_12BIT))
190 goto out;
191
192 spin_lock_irqsave(&ts->lock, flags);
193
194 tsc200x_update_pen_state(ts, tsdata.x, tsdata.y, pressure);
195 mod_timer(&ts->penup_timer,
196 jiffies + msecs_to_jiffies(TSC200X_PENUP_TIME_MS));
197
198 spin_unlock_irqrestore(&ts->lock, flags);
199
200 ts->last_valid_interrupt = jiffies;
201out:
202 return IRQ_HANDLED;
203}
204
205static void tsc200x_penup_timer(struct timer_list *t)
206{
207 struct tsc200x *ts = from_timer(ts, t, penup_timer);
208 unsigned long flags;
209
210 spin_lock_irqsave(&ts->lock, flags);
211 tsc200x_update_pen_state(ts, 0, 0, 0);
212 spin_unlock_irqrestore(&ts->lock, flags);
213}
214
215static void tsc200x_start_scan(struct tsc200x *ts)
216{
217 regmap_write(ts->regmap, TSC200X_REG_CFR0, TSC200X_CFR0_INITVALUE);
218 regmap_write(ts->regmap, TSC200X_REG_CFR1, TSC200X_CFR1_INITVALUE);
219 regmap_write(ts->regmap, TSC200X_REG_CFR2, TSC200X_CFR2_INITVALUE);
220 ts->tsc200x_cmd(ts->dev, TSC200X_CMD_NORMAL);
221}
222
223static void tsc200x_stop_scan(struct tsc200x *ts)
224{
225 ts->tsc200x_cmd(ts->dev, TSC200X_CMD_STOP);
226}
227
228static void tsc200x_reset(struct tsc200x *ts)
229{
230 if (ts->reset_gpio) {
231 gpiod_set_value_cansleep(ts->reset_gpio, 1);
232 usleep_range(100, 500); /* only 10us required */
233 gpiod_set_value_cansleep(ts->reset_gpio, 0);
234 }
235}
236
237/* must be called with ts->mutex held */
238static void __tsc200x_disable(struct tsc200x *ts)
239{
240 tsc200x_stop_scan(ts);
241
242 disable_irq(ts->irq);
243 del_timer_sync(&ts->penup_timer);
244
245 cancel_delayed_work_sync(&ts->esd_work);
246
247 enable_irq(ts->irq);
248}
249
250/* must be called with ts->mutex held */
251static void __tsc200x_enable(struct tsc200x *ts)
252{
253 tsc200x_start_scan(ts);
254
255 if (ts->esd_timeout && ts->reset_gpio) {
256 ts->last_valid_interrupt = jiffies;
257 schedule_delayed_work(&ts->esd_work,
258 round_jiffies_relative(
259 msecs_to_jiffies(ts->esd_timeout)));
260 }
261}
262
263static ssize_t tsc200x_selftest_show(struct device *dev,
264 struct device_attribute *attr,
265 char *buf)
266{
267 struct tsc200x *ts = dev_get_drvdata(dev);
268 unsigned int temp_high;
269 unsigned int temp_high_orig;
270 unsigned int temp_high_test;
271 bool success = true;
272 int error;
273
274 mutex_lock(&ts->mutex);
275
276 /*
277 * Test TSC200X communications via temp high register.
278 */
279 __tsc200x_disable(ts);
280
281 error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high_orig);
282 if (error) {
283 dev_warn(dev, "selftest failed: read error %d\n", error);
284 success = false;
285 goto out;
286 }
287
288 temp_high_test = (temp_high_orig - 1) & MAX_12BIT;
289
290 error = regmap_write(ts->regmap, TSC200X_REG_TEMP_HIGH, temp_high_test);
291 if (error) {
292 dev_warn(dev, "selftest failed: write error %d\n", error);
293 success = false;
294 goto out;
295 }
296
297 error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high);
298 if (error) {
299 dev_warn(dev, "selftest failed: read error %d after write\n",
300 error);
301 success = false;
302 goto out;
303 }
304
305 if (temp_high != temp_high_test) {
306 dev_warn(dev, "selftest failed: %d != %d\n",
307 temp_high, temp_high_test);
308 success = false;
309 }
310
311 /* hardware reset */
312 tsc200x_reset(ts);
313
314 if (!success)
315 goto out;
316
317 /* test that the reset really happened */
318 error = regmap_read(ts->regmap, TSC200X_REG_TEMP_HIGH, &temp_high);
319 if (error) {
320 dev_warn(dev, "selftest failed: read error %d after reset\n",
321 error);
322 success = false;
323 goto out;
324 }
325
326 if (temp_high != temp_high_orig) {
327 dev_warn(dev, "selftest failed after reset: %d != %d\n",
328 temp_high, temp_high_orig);
329 success = false;
330 }
331
332out:
333 __tsc200x_enable(ts);
334 mutex_unlock(&ts->mutex);
335
336 return sprintf(buf, "%d\n", success);
337}
338
339static DEVICE_ATTR(selftest, S_IRUGO, tsc200x_selftest_show, NULL);
340
341static struct attribute *tsc200x_attrs[] = {
342 &dev_attr_selftest.attr,
343 NULL
344};
345
346static umode_t tsc200x_attr_is_visible(struct kobject *kobj,
347 struct attribute *attr, int n)
348{
349 struct device *dev = container_of(kobj, struct device, kobj);
350 struct tsc200x *ts = dev_get_drvdata(dev);
351 umode_t mode = attr->mode;
352
353 if (attr == &dev_attr_selftest.attr) {
354 if (!ts->reset_gpio)
355 mode = 0;
356 }
357
358 return mode;
359}
360
361static const struct attribute_group tsc200x_attr_group = {
362 .is_visible = tsc200x_attr_is_visible,
363 .attrs = tsc200x_attrs,
364};
365
366static void tsc200x_esd_work(struct work_struct *work)
367{
368 struct tsc200x *ts = container_of(work, struct tsc200x, esd_work.work);
369 int error;
370 unsigned int r;
371
372 if (!mutex_trylock(&ts->mutex)) {
373 /*
374 * If the mutex is taken, it means that disable or enable is in
375 * progress. In that case just reschedule the work. If the work
376 * is not needed, it will be canceled by disable.
377 */
378 goto reschedule;
379 }
380
381 if (time_is_after_jiffies(ts->last_valid_interrupt +
382 msecs_to_jiffies(ts->esd_timeout)))
383 goto out;
384
385 /* We should be able to read register without disabling interrupts. */
386 error = regmap_read(ts->regmap, TSC200X_REG_CFR0, &r);
387 if (!error &&
388 !((r ^ TSC200X_CFR0_INITVALUE) & TSC200X_CFR0_RW_MASK)) {
389 goto out;
390 }
391
392 /*
393 * If we could not read our known value from configuration register 0
394 * then we should reset the controller as if from power-up and start
395 * scanning again.
396 */
397 dev_info(ts->dev, "TSC200X not responding - resetting\n");
398
399 disable_irq(ts->irq);
400 del_timer_sync(&ts->penup_timer);
401
402 tsc200x_update_pen_state(ts, 0, 0, 0);
403
404 tsc200x_reset(ts);
405
406 enable_irq(ts->irq);
407 tsc200x_start_scan(ts);
408
409out:
410 mutex_unlock(&ts->mutex);
411reschedule:
412 /* re-arm the watchdog */
413 schedule_delayed_work(&ts->esd_work,
414 round_jiffies_relative(
415 msecs_to_jiffies(ts->esd_timeout)));
416}
417
418static int tsc200x_open(struct input_dev *input)
419{
420 struct tsc200x *ts = input_get_drvdata(input);
421
422 mutex_lock(&ts->mutex);
423
424 if (!ts->suspended)
425 __tsc200x_enable(ts);
426
427 ts->opened = true;
428
429 mutex_unlock(&ts->mutex);
430
431 return 0;
432}
433
434static void tsc200x_close(struct input_dev *input)
435{
436 struct tsc200x *ts = input_get_drvdata(input);
437
438 mutex_lock(&ts->mutex);
439
440 if (!ts->suspended)
441 __tsc200x_disable(ts);
442
443 ts->opened = false;
444
445 mutex_unlock(&ts->mutex);
446}
447
448int tsc200x_probe(struct device *dev, int irq, const struct input_id *tsc_id,
449 struct regmap *regmap,
450 int (*tsc200x_cmd)(struct device *dev, u8 cmd))
451{
452 struct tsc200x *ts;
453 struct input_dev *input_dev;
454 u32 x_plate_ohm;
455 u32 esd_timeout;
456 int error;
457
458 if (irq <= 0) {
459 dev_err(dev, "no irq\n");
460 return -ENODEV;
461 }
462
463 if (IS_ERR(regmap))
464 return PTR_ERR(regmap);
465
466 if (!tsc200x_cmd) {
467 dev_err(dev, "no cmd function\n");
468 return -ENODEV;
469 }
470
471 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
472 if (!ts)
473 return -ENOMEM;
474
475 input_dev = devm_input_allocate_device(dev);
476 if (!input_dev)
477 return -ENOMEM;
478
479 ts->irq = irq;
480 ts->dev = dev;
481 ts->idev = input_dev;
482 ts->regmap = regmap;
483 ts->tsc200x_cmd = tsc200x_cmd;
484
485 error = device_property_read_u32(dev, "ti,x-plate-ohms", &x_plate_ohm);
486 ts->x_plate_ohm = error ? TSC200X_DEF_RESISTOR : x_plate_ohm;
487
488 error = device_property_read_u32(dev, "ti,esd-recovery-timeout-ms",
489 &esd_timeout);
490 ts->esd_timeout = error ? 0 : esd_timeout;
491
492 ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
493 if (IS_ERR(ts->reset_gpio)) {
494 error = PTR_ERR(ts->reset_gpio);
495 dev_err(dev, "error acquiring reset gpio: %d\n", error);
496 return error;
497 }
498
499 ts->vio = devm_regulator_get(dev, "vio");
500 if (IS_ERR(ts->vio)) {
501 error = PTR_ERR(ts->vio);
502 dev_err(dev, "error acquiring vio regulator: %d", error);
503 return error;
504 }
505
506 mutex_init(&ts->mutex);
507
508 spin_lock_init(&ts->lock);
509 timer_setup(&ts->penup_timer, tsc200x_penup_timer, 0);
510
511 INIT_DELAYED_WORK(&ts->esd_work, tsc200x_esd_work);
512
513 snprintf(ts->phys, sizeof(ts->phys),
514 "%s/input-ts", dev_name(dev));
515
516 if (tsc_id->product == 2004) {
517 input_dev->name = "TSC200X touchscreen";
518 } else {
519 input_dev->name = devm_kasprintf(dev, GFP_KERNEL,
520 "TSC%04d touchscreen",
521 tsc_id->product);
522 if (!input_dev->name)
523 return -ENOMEM;
524 }
525
526 input_dev->phys = ts->phys;
527 input_dev->id = *tsc_id;
528
529 input_dev->open = tsc200x_open;
530 input_dev->close = tsc200x_close;
531
532 input_set_drvdata(input_dev, ts);
533
534 __set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
535 input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
536
537 input_set_abs_params(input_dev, ABS_X,
538 0, MAX_12BIT, TSC200X_DEF_X_FUZZ, 0);
539 input_set_abs_params(input_dev, ABS_Y,
540 0, MAX_12BIT, TSC200X_DEF_Y_FUZZ, 0);
541 input_set_abs_params(input_dev, ABS_PRESSURE,
542 0, MAX_12BIT, TSC200X_DEF_P_FUZZ, 0);
543
544 touchscreen_parse_properties(input_dev, false, NULL);
545
546 /* Ensure the touchscreen is off */
547 tsc200x_stop_scan(ts);
548
549 error = devm_request_threaded_irq(dev, irq, NULL,
550 tsc200x_irq_thread,
551 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
552 "tsc200x", ts);
553 if (error) {
554 dev_err(dev, "Failed to request irq, err: %d\n", error);
555 return error;
556 }
557
558 error = regulator_enable(ts->vio);
559 if (error)
560 return error;
561
562 dev_set_drvdata(dev, ts);
563 error = sysfs_create_group(&dev->kobj, &tsc200x_attr_group);
564 if (error) {
565 dev_err(dev,
566 "Failed to create sysfs attributes, err: %d\n", error);
567 goto disable_regulator;
568 }
569
570 error = input_register_device(ts->idev);
571 if (error) {
572 dev_err(dev,
573 "Failed to register input device, err: %d\n", error);
574 goto err_remove_sysfs;
575 }
576
577 irq_set_irq_wake(irq, 1);
578 return 0;
579
580err_remove_sysfs:
581 sysfs_remove_group(&dev->kobj, &tsc200x_attr_group);
582disable_regulator:
583 regulator_disable(ts->vio);
584 return error;
585}
586EXPORT_SYMBOL_GPL(tsc200x_probe);
587
588int tsc200x_remove(struct device *dev)
589{
590 struct tsc200x *ts = dev_get_drvdata(dev);
591
592 sysfs_remove_group(&dev->kobj, &tsc200x_attr_group);
593
594 regulator_disable(ts->vio);
595
596 return 0;
597}
598EXPORT_SYMBOL_GPL(tsc200x_remove);
599
600static int __maybe_unused tsc200x_suspend(struct device *dev)
601{
602 struct tsc200x *ts = dev_get_drvdata(dev);
603
604 mutex_lock(&ts->mutex);
605
606 if (!ts->suspended && ts->opened)
607 __tsc200x_disable(ts);
608
609 ts->suspended = true;
610
611 mutex_unlock(&ts->mutex);
612
613 return 0;
614}
615
616static int __maybe_unused tsc200x_resume(struct device *dev)
617{
618 struct tsc200x *ts = dev_get_drvdata(dev);
619
620 mutex_lock(&ts->mutex);
621
622 if (ts->suspended && ts->opened)
623 __tsc200x_enable(ts);
624
625 ts->suspended = false;
626
627 mutex_unlock(&ts->mutex);
628
629 return 0;
630}
631
632SIMPLE_DEV_PM_OPS(tsc200x_pm_ops, tsc200x_suspend, tsc200x_resume);
633EXPORT_SYMBOL_GPL(tsc200x_pm_ops);
634
635MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>");
636MODULE_DESCRIPTION("TSC200x Touchscreen Driver Core");
637MODULE_LICENSE("GPL");