1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23#include <linux/device.h>
24#include <linux/delay.h>
25#include <linux/input.h>
26#include <linux/interrupt.h>
27#include <linux/irq.h>
28#include <linux/property.h>
29#include <linux/regmap.h>
30#include <linux/slab.h>
31#include <linux/gpio/driver.h>
32
33#include <linux/input/touchscreen.h>
34#include <linux/module.h>
35#include "ad7879.h"
36
37#define AD7879_REG_ZEROS 0
38#define AD7879_REG_CTRL1 1
39#define AD7879_REG_CTRL2 2
40#define AD7879_REG_CTRL3 3
41#define AD7879_REG_AUX1HIGH 4
42#define AD7879_REG_AUX1LOW 5
43#define AD7879_REG_TEMP1HIGH 6
44#define AD7879_REG_TEMP1LOW 7
45#define AD7879_REG_XPLUS 8
46#define AD7879_REG_YPLUS 9
47#define AD7879_REG_Z1 10
48#define AD7879_REG_Z2 11
49#define AD7879_REG_AUXVBAT 12
50#define AD7879_REG_TEMP 13
51#define AD7879_REG_REVID 14
52
53
54#define AD7879_TMR(x) ((x & 0xFF) << 0)
55#define AD7879_ACQ(x) ((x & 0x3) << 8)
56#define AD7879_MODE_NOC (0 << 10)
57#define AD7879_MODE_SCC (1 << 10)
58#define AD7879_MODE_SEQ0 (2 << 10)
59#define AD7879_MODE_SEQ1 (3 << 10)
60#define AD7879_MODE_INT (1 << 15)
61
62
63#define AD7879_FCD(x) ((x & 0x3) << 0)
64#define AD7879_RESET (1 << 4)
65#define AD7879_MFS(x) ((x & 0x3) << 5)
66#define AD7879_AVG(x) ((x & 0x3) << 7)
67#define AD7879_SER (1 << 9)
68#define AD7879_DFR (0 << 9)
69#define AD7879_GPIOPOL (1 << 10)
70#define AD7879_GPIODIR (1 << 11)
71#define AD7879_GPIO_DATA (1 << 12)
72#define AD7879_GPIO_EN (1 << 13)
73#define AD7879_PM(x) ((x & 0x3) << 14)
74#define AD7879_PM_SHUTDOWN (0)
75#define AD7879_PM_DYN (1)
76#define AD7879_PM_FULLON (2)
77
78
79#define AD7879_TEMPMASK_BIT (1<<15)
80#define AD7879_AUXVBATMASK_BIT (1<<14)
81#define AD7879_INTMODE_BIT (1<<13)
82#define AD7879_GPIOALERTMASK_BIT (1<<12)
83#define AD7879_AUXLOW_BIT (1<<11)
84#define AD7879_AUXHIGH_BIT (1<<10)
85#define AD7879_TEMPLOW_BIT (1<<9)
86#define AD7879_TEMPHIGH_BIT (1<<8)
87#define AD7879_YPLUS_BIT (1<<7)
88#define AD7879_XPLUS_BIT (1<<6)
89#define AD7879_Z1_BIT (1<<5)
90#define AD7879_Z2_BIT (1<<4)
91#define AD7879_AUX_BIT (1<<3)
92#define AD7879_VBAT_BIT (1<<2)
93#define AD7879_TEMP_BIT (1<<1)
94
95enum {
96 AD7879_SEQ_YPOS = 0,
97 AD7879_SEQ_XPOS = 1,
98 AD7879_SEQ_Z1 = 2,
99 AD7879_SEQ_Z2 = 3,
100 AD7879_NR_SENSE = 4,
101};
102
103#define MAX_12BIT ((1<<12)-1)
104#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)
105
106struct ad7879 {
107 struct regmap *regmap;
108 struct device *dev;
109 struct input_dev *input;
110 struct timer_list timer;
111#ifdef CONFIG_GPIOLIB
112 struct gpio_chip gc;
113 struct mutex mutex;
114#endif
115 unsigned int irq;
116 bool disabled;
117 bool suspended;
118 bool swap_xy;
119 u16 conversion_data[AD7879_NR_SENSE];
120 char phys[32];
121 u8 first_conversion_delay;
122 u8 acquisition_time;
123 u8 averaging;
124 u8 pen_down_acc_interval;
125 u8 median;
126 u16 x_plate_ohms;
127 u16 cmd_crtl1;
128 u16 cmd_crtl2;
129 u16 cmd_crtl3;
130 int x;
131 int y;
132 int Rt;
133};
134
135static int ad7879_read(struct ad7879 *ts, u8 reg)
136{
137 unsigned int val;
138 int error;
139
140 error = regmap_read(ts->regmap, reg, &val);
141 if (error) {
142 dev_err(ts->dev, "failed to read register %#02x: %d\n",
143 reg, error);
144 return error;
145 }
146
147 return val;
148}
149
150static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
151{
152 int error;
153
154 error = regmap_write(ts->regmap, reg, val);
155 if (error) {
156 dev_err(ts->dev,
157 "failed to write %#04x to register %#02x: %d\n",
158 val, reg, error);
159 return error;
160 }
161
162 return 0;
163}
164
165static int ad7879_report(struct ad7879 *ts)
166{
167 struct input_dev *input_dev = ts->input;
168 unsigned Rt;
169 u16 x, y, z1, z2;
170
171 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
172 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
173 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
174 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
175
176 if (ts->swap_xy)
177 swap(x, y);
178
179
180
181
182
183
184
185
186
187
188
189
190
191 if (likely(x && z1)) {
192
193 Rt = (z2 - z1) * x * ts->x_plate_ohms;
194 Rt /= z1;
195 Rt = (Rt + 2047) >> 12;
196
197
198
199
200
201 if (Rt > input_abs_get_max(input_dev, ABS_PRESSURE))
202 return -EINVAL;
203
204
205
206
207
208
209
210 if (timer_pending(&ts->timer)) {
211
212 input_report_key(input_dev, BTN_TOUCH, 1);
213 input_report_abs(input_dev, ABS_X, ts->x);
214 input_report_abs(input_dev, ABS_Y, ts->y);
215 input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
216 input_sync(input_dev);
217 }
218
219 ts->x = x;
220 ts->y = y;
221 ts->Rt = Rt;
222
223 return 0;
224 }
225
226 return -EINVAL;
227}
228
229static void ad7879_ts_event_release(struct ad7879 *ts)
230{
231 struct input_dev *input_dev = ts->input;
232
233 input_report_abs(input_dev, ABS_PRESSURE, 0);
234 input_report_key(input_dev, BTN_TOUCH, 0);
235 input_sync(input_dev);
236}
237
238static void ad7879_timer(struct timer_list *t)
239{
240 struct ad7879 *ts = from_timer(ts, t, timer);
241
242 ad7879_ts_event_release(ts);
243}
244
245static irqreturn_t ad7879_irq(int irq, void *handle)
246{
247 struct ad7879 *ts = handle;
248 int error;
249
250 error = regmap_bulk_read(ts->regmap, AD7879_REG_XPLUS,
251 ts->conversion_data, AD7879_NR_SENSE);
252 if (error)
253 dev_err_ratelimited(ts->dev, "failed to read %#02x: %d\n",
254 AD7879_REG_XPLUS, error);
255 else if (!ad7879_report(ts))
256 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
257
258 return IRQ_HANDLED;
259}
260
261static void __ad7879_enable(struct ad7879 *ts)
262{
263 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
264 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
265 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
266
267 enable_irq(ts->irq);
268}
269
270static void __ad7879_disable(struct ad7879 *ts)
271{
272 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
273 AD7879_PM(AD7879_PM_SHUTDOWN);
274 disable_irq(ts->irq);
275
276 if (del_timer_sync(&ts->timer))
277 ad7879_ts_event_release(ts);
278
279 ad7879_write(ts, AD7879_REG_CTRL2, reg);
280}
281
282
283static int ad7879_open(struct input_dev *input)
284{
285 struct ad7879 *ts = input_get_drvdata(input);
286
287
288 if (!ts->disabled && !ts->suspended)
289 __ad7879_enable(ts);
290
291 return 0;
292}
293
294static void ad7879_close(struct input_dev *input)
295{
296 struct ad7879 *ts = input_get_drvdata(input);
297
298
299 if (!ts->disabled && !ts->suspended)
300 __ad7879_disable(ts);
301}
302
303static int __maybe_unused ad7879_suspend(struct device *dev)
304{
305 struct ad7879 *ts = dev_get_drvdata(dev);
306
307 mutex_lock(&ts->input->mutex);
308
309 if (!ts->suspended && !ts->disabled && input_device_enabled(ts->input))
310 __ad7879_disable(ts);
311
312 ts->suspended = true;
313
314 mutex_unlock(&ts->input->mutex);
315
316 return 0;
317}
318
319static int __maybe_unused ad7879_resume(struct device *dev)
320{
321 struct ad7879 *ts = dev_get_drvdata(dev);
322
323 mutex_lock(&ts->input->mutex);
324
325 if (ts->suspended && !ts->disabled && input_device_enabled(ts->input))
326 __ad7879_enable(ts);
327
328 ts->suspended = false;
329
330 mutex_unlock(&ts->input->mutex);
331
332 return 0;
333}
334
335SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
336EXPORT_SYMBOL(ad7879_pm_ops);
337
338static void ad7879_toggle(struct ad7879 *ts, bool disable)
339{
340 mutex_lock(&ts->input->mutex);
341
342 if (!ts->suspended && input_device_enabled(ts->input)) {
343
344 if (disable) {
345 if (ts->disabled)
346 __ad7879_enable(ts);
347 } else {
348 if (!ts->disabled)
349 __ad7879_disable(ts);
350 }
351 }
352
353 ts->disabled = disable;
354
355 mutex_unlock(&ts->input->mutex);
356}
357
358static ssize_t ad7879_disable_show(struct device *dev,
359 struct device_attribute *attr, char *buf)
360{
361 struct ad7879 *ts = dev_get_drvdata(dev);
362
363 return sprintf(buf, "%u\n", ts->disabled);
364}
365
366static ssize_t ad7879_disable_store(struct device *dev,
367 struct device_attribute *attr,
368 const char *buf, size_t count)
369{
370 struct ad7879 *ts = dev_get_drvdata(dev);
371 unsigned int val;
372 int error;
373
374 error = kstrtouint(buf, 10, &val);
375 if (error)
376 return error;
377
378 ad7879_toggle(ts, val);
379
380 return count;
381}
382
383static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
384
385static struct attribute *ad7879_attributes[] = {
386 &dev_attr_disable.attr,
387 NULL
388};
389
390static const struct attribute_group ad7879_attr_group = {
391 .attrs = ad7879_attributes,
392};
393
394#ifdef CONFIG_GPIOLIB
395static int ad7879_gpio_direction_input(struct gpio_chip *chip,
396 unsigned gpio)
397{
398 struct ad7879 *ts = gpiochip_get_data(chip);
399 int err;
400
401 mutex_lock(&ts->mutex);
402 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
403 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
404 mutex_unlock(&ts->mutex);
405
406 return err;
407}
408
409static int ad7879_gpio_direction_output(struct gpio_chip *chip,
410 unsigned gpio, int level)
411{
412 struct ad7879 *ts = gpiochip_get_data(chip);
413 int err;
414
415 mutex_lock(&ts->mutex);
416 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
417 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
418 if (level)
419 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
420 else
421 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
422
423 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
424 mutex_unlock(&ts->mutex);
425
426 return err;
427}
428
429static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
430{
431 struct ad7879 *ts = gpiochip_get_data(chip);
432 u16 val;
433
434 mutex_lock(&ts->mutex);
435 val = ad7879_read(ts, AD7879_REG_CTRL2);
436 mutex_unlock(&ts->mutex);
437
438 return !!(val & AD7879_GPIO_DATA);
439}
440
441static void ad7879_gpio_set_value(struct gpio_chip *chip,
442 unsigned gpio, int value)
443{
444 struct ad7879 *ts = gpiochip_get_data(chip);
445
446 mutex_lock(&ts->mutex);
447 if (value)
448 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
449 else
450 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
451
452 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
453 mutex_unlock(&ts->mutex);
454}
455
456static int ad7879_gpio_add(struct ad7879 *ts)
457{
458 int ret = 0;
459
460 mutex_init(&ts->mutex);
461
462
463 if (!device_property_read_bool(ts->dev, "gpio-controller"))
464 return 0;
465
466 ts->gc.direction_input = ad7879_gpio_direction_input;
467 ts->gc.direction_output = ad7879_gpio_direction_output;
468 ts->gc.get = ad7879_gpio_get_value;
469 ts->gc.set = ad7879_gpio_set_value;
470 ts->gc.can_sleep = 1;
471 ts->gc.base = -1;
472 ts->gc.ngpio = 1;
473 ts->gc.label = "AD7879-GPIO";
474 ts->gc.owner = THIS_MODULE;
475 ts->gc.parent = ts->dev;
476
477 ret = devm_gpiochip_add_data(ts->dev, &ts->gc, ts);
478 if (ret)
479 dev_err(ts->dev, "failed to register gpio %d\n",
480 ts->gc.base);
481
482 return ret;
483}
484#else
485static int ad7879_gpio_add(struct ad7879 *ts)
486{
487 return 0;
488}
489#endif
490
491static int ad7879_parse_dt(struct device *dev, struct ad7879 *ts)
492{
493 int err;
494 u32 tmp;
495
496 err = device_property_read_u32(dev, "adi,resistance-plate-x", &tmp);
497 if (err) {
498 dev_err(dev, "failed to get resistance-plate-x property\n");
499 return err;
500 }
501 ts->x_plate_ohms = (u16)tmp;
502
503 device_property_read_u8(dev, "adi,first-conversion-delay",
504 &ts->first_conversion_delay);
505 device_property_read_u8(dev, "adi,acquisition-time",
506 &ts->acquisition_time);
507 device_property_read_u8(dev, "adi,median-filter-size", &ts->median);
508 device_property_read_u8(dev, "adi,averaging", &ts->averaging);
509 device_property_read_u8(dev, "adi,conversion-interval",
510 &ts->pen_down_acc_interval);
511
512 ts->swap_xy = device_property_read_bool(dev, "touchscreen-swapped-x-y");
513
514 return 0;
515}
516
517int ad7879_probe(struct device *dev, struct regmap *regmap,
518 int irq, u16 bustype, u8 devid)
519{
520 struct ad7879 *ts;
521 struct input_dev *input_dev;
522 int err;
523 u16 revid;
524
525 if (irq <= 0) {
526 dev_err(dev, "No IRQ specified\n");
527 return -EINVAL;
528 }
529
530 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
531 if (!ts)
532 return -ENOMEM;
533
534 err = ad7879_parse_dt(dev, ts);
535 if (err)
536 return err;
537
538 input_dev = devm_input_allocate_device(dev);
539 if (!input_dev) {
540 dev_err(dev, "Failed to allocate input device\n");
541 return -ENOMEM;
542 }
543
544 ts->dev = dev;
545 ts->input = input_dev;
546 ts->irq = irq;
547 ts->regmap = regmap;
548
549 timer_setup(&ts->timer, ad7879_timer, 0);
550 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
551
552 input_dev->name = "AD7879 Touchscreen";
553 input_dev->phys = ts->phys;
554 input_dev->dev.parent = dev;
555 input_dev->id.bustype = bustype;
556
557 input_dev->open = ad7879_open;
558 input_dev->close = ad7879_close;
559
560 input_set_drvdata(input_dev, ts);
561
562 input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
563
564 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
565 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
566 input_set_capability(input_dev, EV_ABS, ABS_PRESSURE);
567 touchscreen_parse_properties(input_dev, false, NULL);
568 if (!input_abs_get_max(input_dev, ABS_PRESSURE)) {
569 dev_err(dev, "Touchscreen pressure is not specified\n");
570 return -EINVAL;
571 }
572
573 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
574 if (err < 0) {
575 dev_err(dev, "Failed to write %s\n", input_dev->name);
576 return err;
577 }
578
579 revid = ad7879_read(ts, AD7879_REG_REVID);
580 input_dev->id.product = (revid & 0xff);
581 input_dev->id.version = revid >> 8;
582 if (input_dev->id.product != devid) {
583 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
584 input_dev->name, devid, revid);
585 return -ENODEV;
586 }
587
588 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
589 AD7879_XPLUS_BIT |
590 AD7879_Z2_BIT |
591 AD7879_Z1_BIT |
592 AD7879_TEMPMASK_BIT |
593 AD7879_AUXVBATMASK_BIT |
594 AD7879_GPIOALERTMASK_BIT;
595
596 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
597 AD7879_AVG(ts->averaging) |
598 AD7879_MFS(ts->median) |
599 AD7879_FCD(ts->first_conversion_delay);
600
601 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
602 AD7879_ACQ(ts->acquisition_time) |
603 AD7879_TMR(ts->pen_down_acc_interval);
604
605 err = devm_request_threaded_irq(dev, ts->irq, NULL, ad7879_irq,
606 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
607 dev_name(dev), ts);
608 if (err) {
609 dev_err(dev, "Failed to request IRQ: %d\n", err);
610 return err;
611 }
612
613 __ad7879_disable(ts);
614
615 err = devm_device_add_group(dev, &ad7879_attr_group);
616 if (err)
617 return err;
618
619 err = ad7879_gpio_add(ts);
620 if (err)
621 return err;
622
623 err = input_register_device(input_dev);
624 if (err)
625 return err;
626
627 dev_set_drvdata(dev, ts);
628
629 return 0;
630}
631EXPORT_SYMBOL(ad7879_probe);
632
633MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
634MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
635MODULE_LICENSE("GPL");
636
