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24#include <linux/device.h>
25#include <linux/delay.h>
26#include <linux/input.h>
27#include <linux/interrupt.h>
28#include <linux/irq.h>
29#include <linux/property.h>
30#include <linux/regmap.h>
31#include <linux/slab.h>
32#include <linux/gpio.h>
33
34#include <linux/input/touchscreen.h>
35#include <linux/platform_data/ad7879.h>
36#include <linux/module.h>
37#include "ad7879.h"
38
39#define AD7879_REG_ZEROS 0
40#define AD7879_REG_CTRL1 1
41#define AD7879_REG_CTRL2 2
42#define AD7879_REG_CTRL3 3
43#define AD7879_REG_AUX1HIGH 4
44#define AD7879_REG_AUX1LOW 5
45#define AD7879_REG_TEMP1HIGH 6
46#define AD7879_REG_TEMP1LOW 7
47#define AD7879_REG_XPLUS 8
48#define AD7879_REG_YPLUS 9
49#define AD7879_REG_Z1 10
50#define AD7879_REG_Z2 11
51#define AD7879_REG_AUXVBAT 12
52#define AD7879_REG_TEMP 13
53#define AD7879_REG_REVID 14
54
55
56#define AD7879_TMR(x) ((x & 0xFF) << 0)
57#define AD7879_ACQ(x) ((x & 0x3) << 8)
58#define AD7879_MODE_NOC (0 << 10)
59#define AD7879_MODE_SCC (1 << 10)
60#define AD7879_MODE_SEQ0 (2 << 10)
61#define AD7879_MODE_SEQ1 (3 << 10)
62#define AD7879_MODE_INT (1 << 15)
63
64
65#define AD7879_FCD(x) ((x & 0x3) << 0)
66#define AD7879_RESET (1 << 4)
67#define AD7879_MFS(x) ((x & 0x3) << 5)
68#define AD7879_AVG(x) ((x & 0x3) << 7)
69#define AD7879_SER (1 << 9)
70#define AD7879_DFR (0 << 9)
71#define AD7879_GPIOPOL (1 << 10)
72#define AD7879_GPIODIR (1 << 11)
73#define AD7879_GPIO_DATA (1 << 12)
74#define AD7879_GPIO_EN (1 << 13)
75#define AD7879_PM(x) ((x & 0x3) << 14)
76#define AD7879_PM_SHUTDOWN (0)
77#define AD7879_PM_DYN (1)
78#define AD7879_PM_FULLON (2)
79
80
81#define AD7879_TEMPMASK_BIT (1<<15)
82#define AD7879_AUXVBATMASK_BIT (1<<14)
83#define AD7879_INTMODE_BIT (1<<13)
84#define AD7879_GPIOALERTMASK_BIT (1<<12)
85#define AD7879_AUXLOW_BIT (1<<11)
86#define AD7879_AUXHIGH_BIT (1<<10)
87#define AD7879_TEMPLOW_BIT (1<<9)
88#define AD7879_TEMPHIGH_BIT (1<<8)
89#define AD7879_YPLUS_BIT (1<<7)
90#define AD7879_XPLUS_BIT (1<<6)
91#define AD7879_Z1_BIT (1<<5)
92#define AD7879_Z2_BIT (1<<4)
93#define AD7879_AUX_BIT (1<<3)
94#define AD7879_VBAT_BIT (1<<2)
95#define AD7879_TEMP_BIT (1<<1)
96
97enum {
98 AD7879_SEQ_YPOS = 0,
99 AD7879_SEQ_XPOS = 1,
100 AD7879_SEQ_Z1 = 2,
101 AD7879_SEQ_Z2 = 3,
102 AD7879_NR_SENSE = 4,
103};
104
105#define MAX_12BIT ((1<<12)-1)
106#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)
107
108struct ad7879 {
109 struct regmap *regmap;
110 struct device *dev;
111 struct input_dev *input;
112 struct timer_list timer;
113#ifdef CONFIG_GPIOLIB
114 struct gpio_chip gc;
115 struct mutex mutex;
116#endif
117 unsigned int irq;
118 bool disabled;
119 bool suspended;
120 bool swap_xy;
121 u16 conversion_data[AD7879_NR_SENSE];
122 char phys[32];
123 u8 first_conversion_delay;
124 u8 acquisition_time;
125 u8 averaging;
126 u8 pen_down_acc_interval;
127 u8 median;
128 u16 x_plate_ohms;
129 u16 cmd_crtl1;
130 u16 cmd_crtl2;
131 u16 cmd_crtl3;
132 int x;
133 int y;
134 int Rt;
135};
136
137static int ad7879_read(struct ad7879 *ts, u8 reg)
138{
139 unsigned int val;
140 int error;
141
142 error = regmap_read(ts->regmap, reg, &val);
143 if (error) {
144 dev_err(ts->dev, "failed to read register %#02x: %d\n",
145 reg, error);
146 return error;
147 }
148
149 return val;
150}
151
152static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
153{
154 int error;
155
156 error = regmap_write(ts->regmap, reg, val);
157 if (error) {
158 dev_err(ts->dev,
159 "failed to write %#04x to register %#02x: %d\n",
160 val, reg, error);
161 return error;
162 }
163
164 return 0;
165}
166
167static int ad7879_report(struct ad7879 *ts)
168{
169 struct input_dev *input_dev = ts->input;
170 unsigned Rt;
171 u16 x, y, z1, z2;
172
173 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
174 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
175 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
176 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
177
178 if (ts->swap_xy)
179 swap(x, y);
180
181
182
183
184
185
186
187
188
189
190
191
192
193 if (likely(x && z1)) {
194
195 Rt = (z2 - z1) * x * ts->x_plate_ohms;
196 Rt /= z1;
197 Rt = (Rt + 2047) >> 12;
198
199
200
201
202
203 if (Rt > input_abs_get_max(input_dev, ABS_PRESSURE))
204 return -EINVAL;
205
206
207
208
209
210
211
212 if (timer_pending(&ts->timer)) {
213
214 input_report_key(input_dev, BTN_TOUCH, 1);
215 input_report_abs(input_dev, ABS_X, ts->x);
216 input_report_abs(input_dev, ABS_Y, ts->y);
217 input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
218 input_sync(input_dev);
219 }
220
221 ts->x = x;
222 ts->y = y;
223 ts->Rt = Rt;
224
225 return 0;
226 }
227
228 return -EINVAL;
229}
230
231static void ad7879_ts_event_release(struct ad7879 *ts)
232{
233 struct input_dev *input_dev = ts->input;
234
235 input_report_abs(input_dev, ABS_PRESSURE, 0);
236 input_report_key(input_dev, BTN_TOUCH, 0);
237 input_sync(input_dev);
238}
239
240static void ad7879_timer(struct timer_list *t)
241{
242 struct ad7879 *ts = from_timer(ts, t, timer);
243
244 ad7879_ts_event_release(ts);
245}
246
247static irqreturn_t ad7879_irq(int irq, void *handle)
248{
249 struct ad7879 *ts = handle;
250
251 regmap_bulk_read(ts->regmap, AD7879_REG_XPLUS,
252 ts->conversion_data, AD7879_NR_SENSE);
253
254 if (!ad7879_report(ts))
255 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
256
257 return IRQ_HANDLED;
258}
259
260static void __ad7879_enable(struct ad7879 *ts)
261{
262 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
263 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
264 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
265
266 enable_irq(ts->irq);
267}
268
269static void __ad7879_disable(struct ad7879 *ts)
270{
271 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
272 AD7879_PM(AD7879_PM_SHUTDOWN);
273 disable_irq(ts->irq);
274
275 if (del_timer_sync(&ts->timer))
276 ad7879_ts_event_release(ts);
277
278 ad7879_write(ts, AD7879_REG_CTRL2, reg);
279}
280
281
282static int ad7879_open(struct input_dev *input)
283{
284 struct ad7879 *ts = input_get_drvdata(input);
285
286
287 if (!ts->disabled && !ts->suspended)
288 __ad7879_enable(ts);
289
290 return 0;
291}
292
293static void ad7879_close(struct input_dev* input)
294{
295 struct ad7879 *ts = input_get_drvdata(input);
296
297
298 if (!ts->disabled && !ts->suspended)
299 __ad7879_disable(ts);
300}
301
302static int __maybe_unused ad7879_suspend(struct device *dev)
303{
304 struct ad7879 *ts = dev_get_drvdata(dev);
305
306 mutex_lock(&ts->input->mutex);
307
308 if (!ts->suspended && !ts->disabled && ts->input->users)
309 __ad7879_disable(ts);
310
311 ts->suspended = true;
312
313 mutex_unlock(&ts->input->mutex);
314
315 return 0;
316}
317
318static int __maybe_unused ad7879_resume(struct device *dev)
319{
320 struct ad7879 *ts = dev_get_drvdata(dev);
321
322 mutex_lock(&ts->input->mutex);
323
324 if (ts->suspended && !ts->disabled && ts->input->users)
325 __ad7879_enable(ts);
326
327 ts->suspended = false;
328
329 mutex_unlock(&ts->input->mutex);
330
331 return 0;
332}
333
334SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
335EXPORT_SYMBOL(ad7879_pm_ops);
336
337static void ad7879_toggle(struct ad7879 *ts, bool disable)
338{
339 mutex_lock(&ts->input->mutex);
340
341 if (!ts->suspended && ts->input->users != 0) {
342
343 if (disable) {
344 if (ts->disabled)
345 __ad7879_enable(ts);
346 } else {
347 if (!ts->disabled)
348 __ad7879_disable(ts);
349 }
350 }
351
352 ts->disabled = disable;
353
354 mutex_unlock(&ts->input->mutex);
355}
356
357static ssize_t ad7879_disable_show(struct device *dev,
358 struct device_attribute *attr, char *buf)
359{
360 struct ad7879 *ts = dev_get_drvdata(dev);
361
362 return sprintf(buf, "%u\n", ts->disabled);
363}
364
365static ssize_t ad7879_disable_store(struct device *dev,
366 struct device_attribute *attr,
367 const char *buf, size_t count)
368{
369 struct ad7879 *ts = dev_get_drvdata(dev);
370 unsigned int val;
371 int error;
372
373 error = kstrtouint(buf, 10, &val);
374 if (error)
375 return error;
376
377 ad7879_toggle(ts, val);
378
379 return count;
380}
381
382static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
383
384static struct attribute *ad7879_attributes[] = {
385 &dev_attr_disable.attr,
386 NULL
387};
388
389static const struct attribute_group ad7879_attr_group = {
390 .attrs = ad7879_attributes,
391};
392
393#ifdef CONFIG_GPIOLIB
394static int ad7879_gpio_direction_input(struct gpio_chip *chip,
395 unsigned gpio)
396{
397 struct ad7879 *ts = gpiochip_get_data(chip);
398 int err;
399
400 mutex_lock(&ts->mutex);
401 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
402 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
403 mutex_unlock(&ts->mutex);
404
405 return err;
406}
407
408static int ad7879_gpio_direction_output(struct gpio_chip *chip,
409 unsigned gpio, int level)
410{
411 struct ad7879 *ts = gpiochip_get_data(chip);
412 int err;
413
414 mutex_lock(&ts->mutex);
415 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
416 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
417 if (level)
418 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
419 else
420 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
421
422 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
423 mutex_unlock(&ts->mutex);
424
425 return err;
426}
427
428static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
429{
430 struct ad7879 *ts = gpiochip_get_data(chip);
431 u16 val;
432
433 mutex_lock(&ts->mutex);
434 val = ad7879_read(ts, AD7879_REG_CTRL2);
435 mutex_unlock(&ts->mutex);
436
437 return !!(val & AD7879_GPIO_DATA);
438}
439
440static void ad7879_gpio_set_value(struct gpio_chip *chip,
441 unsigned gpio, int value)
442{
443 struct ad7879 *ts = gpiochip_get_data(chip);
444
445 mutex_lock(&ts->mutex);
446 if (value)
447 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
448 else
449 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
450
451 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
452 mutex_unlock(&ts->mutex);
453}
454
455static int ad7879_gpio_add(struct ad7879 *ts,
456 const struct ad7879_platform_data *pdata)
457{
458 bool gpio_export;
459 int gpio_base;
460 int ret = 0;
461
462 if (pdata) {
463 gpio_export = pdata->gpio_export;
464 gpio_base = pdata->gpio_base;
465 } else {
466 gpio_export = device_property_read_bool(ts->dev,
467 "gpio-controller");
468 gpio_base = -1;
469 }
470
471 mutex_init(&ts->mutex);
472
473 if (gpio_export) {
474 ts->gc.direction_input = ad7879_gpio_direction_input;
475 ts->gc.direction_output = ad7879_gpio_direction_output;
476 ts->gc.get = ad7879_gpio_get_value;
477 ts->gc.set = ad7879_gpio_set_value;
478 ts->gc.can_sleep = 1;
479 ts->gc.base = gpio_base;
480 ts->gc.ngpio = 1;
481 ts->gc.label = "AD7879-GPIO";
482 ts->gc.owner = THIS_MODULE;
483 ts->gc.parent = ts->dev;
484
485 ret = devm_gpiochip_add_data(ts->dev, &ts->gc, ts);
486 if (ret)
487 dev_err(ts->dev, "failed to register gpio %d\n",
488 ts->gc.base);
489 }
490
491 return ret;
492}
493#else
494static int ad7879_gpio_add(struct ad7879 *ts,
495 const struct ad7879_platform_data *pdata)
496{
497 return 0;
498}
499#endif
500
501static int ad7879_parse_dt(struct device *dev, struct ad7879 *ts)
502{
503 int err;
504 u32 tmp;
505
506 err = device_property_read_u32(dev, "adi,resistance-plate-x", &tmp);
507 if (err) {
508 dev_err(dev, "failed to get resistance-plate-x property\n");
509 return err;
510 }
511 ts->x_plate_ohms = (u16)tmp;
512
513 device_property_read_u8(dev, "adi,first-conversion-delay",
514 &ts->first_conversion_delay);
515 device_property_read_u8(dev, "adi,acquisition-time",
516 &ts->acquisition_time);
517 device_property_read_u8(dev, "adi,median-filter-size", &ts->median);
518 device_property_read_u8(dev, "adi,averaging", &ts->averaging);
519 device_property_read_u8(dev, "adi,conversion-interval",
520 &ts->pen_down_acc_interval);
521
522 ts->swap_xy = device_property_read_bool(dev, "touchscreen-swapped-x-y");
523
524 return 0;
525}
526
527int ad7879_probe(struct device *dev, struct regmap *regmap,
528 int irq, u16 bustype, u8 devid)
529{
530 struct ad7879_platform_data *pdata = dev_get_platdata(dev);
531 struct ad7879 *ts;
532 struct input_dev *input_dev;
533 int err;
534 u16 revid;
535
536 if (irq <= 0) {
537 dev_err(dev, "No IRQ specified\n");
538 return -EINVAL;
539 }
540
541 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
542 if (!ts)
543 return -ENOMEM;
544
545 if (pdata) {
546
547 ts->swap_xy = !pdata->swap_xy;
548
549 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
550
551 ts->first_conversion_delay = pdata->first_conversion_delay;
552 ts->acquisition_time = pdata->acquisition_time;
553 ts->averaging = pdata->averaging;
554 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
555 ts->median = pdata->median;
556 } else {
557 err = ad7879_parse_dt(dev, ts);
558 if (err)
559 return err;
560 }
561
562 input_dev = devm_input_allocate_device(dev);
563 if (!input_dev) {
564 dev_err(dev, "Failed to allocate input device\n");
565 return -ENOMEM;
566 }
567
568 ts->dev = dev;
569 ts->input = input_dev;
570 ts->irq = irq;
571 ts->regmap = regmap;
572
573 timer_setup(&ts->timer, ad7879_timer, 0);
574 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
575
576 input_dev->name = "AD7879 Touchscreen";
577 input_dev->phys = ts->phys;
578 input_dev->dev.parent = dev;
579 input_dev->id.bustype = bustype;
580
581 input_dev->open = ad7879_open;
582 input_dev->close = ad7879_close;
583
584 input_set_drvdata(input_dev, ts);
585
586 input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
587
588 if (pdata) {
589 input_set_abs_params(input_dev, ABS_X,
590 pdata->x_min ? : 0,
591 pdata->x_max ? : MAX_12BIT,
592 0, 0);
593 input_set_abs_params(input_dev, ABS_Y,
594 pdata->y_min ? : 0,
595 pdata->y_max ? : MAX_12BIT,
596 0, 0);
597 input_set_abs_params(input_dev, ABS_PRESSURE,
598 pdata->pressure_min,
599 pdata->pressure_max ? : ~0,
600 0, 0);
601 } else {
602 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
603 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
604 input_set_capability(input_dev, EV_ABS, ABS_PRESSURE);
605 touchscreen_parse_properties(input_dev, false, NULL);
606 if (!input_abs_get_max(input_dev, ABS_PRESSURE)) {
607 dev_err(dev, "Touchscreen pressure is not specified\n");
608 return -EINVAL;
609 }
610 }
611
612 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
613 if (err < 0) {
614 dev_err(dev, "Failed to write %s\n", input_dev->name);
615 return err;
616 }
617
618 revid = ad7879_read(ts, AD7879_REG_REVID);
619 input_dev->id.product = (revid & 0xff);
620 input_dev->id.version = revid >> 8;
621 if (input_dev->id.product != devid) {
622 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
623 input_dev->name, devid, revid);
624 return -ENODEV;
625 }
626
627 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
628 AD7879_XPLUS_BIT |
629 AD7879_Z2_BIT |
630 AD7879_Z1_BIT |
631 AD7879_TEMPMASK_BIT |
632 AD7879_AUXVBATMASK_BIT |
633 AD7879_GPIOALERTMASK_BIT;
634
635 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
636 AD7879_AVG(ts->averaging) |
637 AD7879_MFS(ts->median) |
638 AD7879_FCD(ts->first_conversion_delay);
639
640 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
641 AD7879_ACQ(ts->acquisition_time) |
642 AD7879_TMR(ts->pen_down_acc_interval);
643
644 err = devm_request_threaded_irq(dev, ts->irq, NULL, ad7879_irq,
645 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
646 dev_name(dev), ts);
647 if (err) {
648 dev_err(dev, "Failed to request IRQ: %d\n", err);
649 return err;
650 }
651
652 __ad7879_disable(ts);
653
654 err = devm_device_add_group(dev, &ad7879_attr_group);
655 if (err)
656 return err;
657
658 err = ad7879_gpio_add(ts, pdata);
659 if (err)
660 return err;
661
662 err = input_register_device(input_dev);
663 if (err)
664 return err;
665
666 dev_set_drvdata(dev, ts);
667
668 return 0;
669}
670EXPORT_SYMBOL(ad7879_probe);
671
672MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
673MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
674MODULE_LICENSE("GPL");
675
