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1/*
2 * AD7879/AD7889 based touchscreen and GPIO driver
3 *
4 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
5 *
6 * Licensed under the GPL-2 or later.
7 *
8 * History:
9 * Copyright (c) 2005 David Brownell
10 * Copyright (c) 2006 Nokia Corporation
11 * Various changes: Imre Deak <imre.deak@nokia.com>
12 *
13 * Using code from:
14 * - corgi_ts.c
15 * Copyright (C) 2004-2005 Richard Purdie
16 * - omap_ts.[hc], ads7846.h, ts_osk.c
17 * Copyright (C) 2002 MontaVista Software
18 * Copyright (C) 2004 Texas Instruments
19 * Copyright (C) 2005 Dirk Behme
20 * - ad7877.c
21 * Copyright (C) 2006-2008 Analog Devices Inc.
22 */
23
24#include <linux/device.h>
25#include <linux/init.h>
26#include <linux/delay.h>
27#include <linux/input.h>
28#include <linux/interrupt.h>
29#include <linux/irq.h>
30#include <linux/slab.h>
31#include <linux/spi/spi.h>
32#include <linux/i2c.h>
33#include <linux/gpio.h>
34
35#include <linux/spi/ad7879.h>
36#include "ad7879.h"
37
38#define AD7879_REG_ZEROS 0
39#define AD7879_REG_CTRL1 1
40#define AD7879_REG_CTRL2 2
41#define AD7879_REG_CTRL3 3
42#define AD7879_REG_AUX1HIGH 4
43#define AD7879_REG_AUX1LOW 5
44#define AD7879_REG_TEMP1HIGH 6
45#define AD7879_REG_TEMP1LOW 7
46#define AD7879_REG_XPLUS 8
47#define AD7879_REG_YPLUS 9
48#define AD7879_REG_Z1 10
49#define AD7879_REG_Z2 11
50#define AD7879_REG_AUXVBAT 12
51#define AD7879_REG_TEMP 13
52#define AD7879_REG_REVID 14
53
54/* Control REG 1 */
55#define AD7879_TMR(x) ((x & 0xFF) << 0)
56#define AD7879_ACQ(x) ((x & 0x3) << 8)
57#define AD7879_MODE_NOC (0 << 10) /* Do not convert */
58#define AD7879_MODE_SCC (1 << 10) /* Single channel conversion */
59#define AD7879_MODE_SEQ0 (2 << 10) /* Sequence 0 in Slave Mode */
60#define AD7879_MODE_SEQ1 (3 << 10) /* Sequence 1 in Master Mode */
61#define AD7879_MODE_INT (1 << 15) /* PENIRQ disabled INT enabled */
62
63/* Control REG 2 */
64#define AD7879_FCD(x) ((x & 0x3) << 0)
65#define AD7879_RESET (1 << 4)
66#define AD7879_MFS(x) ((x & 0x3) << 5)
67#define AD7879_AVG(x) ((x & 0x3) << 7)
68#define AD7879_SER (1 << 9) /* non-differential */
69#define AD7879_DFR (0 << 9) /* differential */
70#define AD7879_GPIOPOL (1 << 10)
71#define AD7879_GPIODIR (1 << 11)
72#define AD7879_GPIO_DATA (1 << 12)
73#define AD7879_GPIO_EN (1 << 13)
74#define AD7879_PM(x) ((x & 0x3) << 14)
75#define AD7879_PM_SHUTDOWN (0)
76#define AD7879_PM_DYN (1)
77#define AD7879_PM_FULLON (2)
78
79/* Control REG 3 */
80#define AD7879_TEMPMASK_BIT (1<<15)
81#define AD7879_AUXVBATMASK_BIT (1<<14)
82#define AD7879_INTMODE_BIT (1<<13)
83#define AD7879_GPIOALERTMASK_BIT (1<<12)
84#define AD7879_AUXLOW_BIT (1<<11)
85#define AD7879_AUXHIGH_BIT (1<<10)
86#define AD7879_TEMPLOW_BIT (1<<9)
87#define AD7879_TEMPHIGH_BIT (1<<8)
88#define AD7879_YPLUS_BIT (1<<7)
89#define AD7879_XPLUS_BIT (1<<6)
90#define AD7879_Z1_BIT (1<<5)
91#define AD7879_Z2_BIT (1<<4)
92#define AD7879_AUX_BIT (1<<3)
93#define AD7879_VBAT_BIT (1<<2)
94#define AD7879_TEMP_BIT (1<<1)
95
96enum {
97 AD7879_SEQ_XPOS = 0,
98 AD7879_SEQ_YPOS = 1,
99 AD7879_SEQ_Z1 = 2,
100 AD7879_SEQ_Z2 = 3,
101 AD7879_NR_SENSE = 4,
102};
103
104#define MAX_12BIT ((1<<12)-1)
105#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)
106
107struct ad7879 {
108 const struct ad7879_bus_ops *bops;
109
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; /* P: input->mutex */
119 bool suspended; /* P: input->mutex */
120 u16 conversion_data[AD7879_NR_SENSE];
121 char phys[32];
122 u8 first_conversion_delay;
123 u8 acquisition_time;
124 u8 averaging;
125 u8 pen_down_acc_interval;
126 u8 median;
127 u16 x_plate_ohms;
128 u16 pressure_max;
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 return ts->bops->read(ts->dev, reg);
140}
141
142static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
143{
144 return ts->bops->multi_read(ts->dev, first_reg, count, buf);
145}
146
147static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
148{
149 return ts->bops->write(ts->dev, reg, val);
150}
151
152static int ad7879_report(struct ad7879 *ts)
153{
154 struct input_dev *input_dev = ts->input;
155 unsigned Rt;
156 u16 x, y, z1, z2;
157
158 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
159 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
160 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
161 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
162
163 /*
164 * The samples processed here are already preprocessed by the AD7879.
165 * The preprocessing function consists of a median and an averaging
166 * filter. The combination of these two techniques provides a robust
167 * solution, discarding the spurious noise in the signal and keeping
168 * only the data of interest. The size of both filters is
169 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other
170 * user-programmable conversion controls include variable acquisition
171 * time, and first conversion delay. Up to 16 averages can be taken
172 * per conversion.
173 */
174
175 if (likely(x && z1)) {
176 /* compute touch pressure resistance using equation #1 */
177 Rt = (z2 - z1) * x * ts->x_plate_ohms;
178 Rt /= z1;
179 Rt = (Rt + 2047) >> 12;
180
181 /*
182 * Sample found inconsistent, pressure is beyond
183 * the maximum. Don't report it to user space.
184 */
185 if (Rt > ts->pressure_max)
186 return -EINVAL;
187
188 /*
189 * Note that we delay reporting events by one sample.
190 * This is done to avoid reporting last sample of the
191 * touch sequence, which may be incomplete if finger
192 * leaves the surface before last reading is taken.
193 */
194 if (timer_pending(&ts->timer)) {
195 /* Touch continues */
196 input_report_key(input_dev, BTN_TOUCH, 1);
197 input_report_abs(input_dev, ABS_X, ts->x);
198 input_report_abs(input_dev, ABS_Y, ts->y);
199 input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
200 input_sync(input_dev);
201 }
202
203 ts->x = x;
204 ts->y = y;
205 ts->Rt = Rt;
206
207 return 0;
208 }
209
210 return -EINVAL;
211}
212
213static void ad7879_ts_event_release(struct ad7879 *ts)
214{
215 struct input_dev *input_dev = ts->input;
216
217 input_report_abs(input_dev, ABS_PRESSURE, 0);
218 input_report_key(input_dev, BTN_TOUCH, 0);
219 input_sync(input_dev);
220}
221
222static void ad7879_timer(unsigned long handle)
223{
224 struct ad7879 *ts = (void *)handle;
225
226 ad7879_ts_event_release(ts);
227}
228
229static irqreturn_t ad7879_irq(int irq, void *handle)
230{
231 struct ad7879 *ts = handle;
232
233 ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
234
235 if (!ad7879_report(ts))
236 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
237
238 return IRQ_HANDLED;
239}
240
241static void __ad7879_enable(struct ad7879 *ts)
242{
243 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
244 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
245 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
246
247 enable_irq(ts->irq);
248}
249
250static void __ad7879_disable(struct ad7879 *ts)
251{
252 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
253 AD7879_PM(AD7879_PM_SHUTDOWN);
254 disable_irq(ts->irq);
255
256 if (del_timer_sync(&ts->timer))
257 ad7879_ts_event_release(ts);
258
259 ad7879_write(ts, AD7879_REG_CTRL2, reg);
260}
261
262
263static int ad7879_open(struct input_dev *input)
264{
265 struct ad7879 *ts = input_get_drvdata(input);
266
267 /* protected by input->mutex */
268 if (!ts->disabled && !ts->suspended)
269 __ad7879_enable(ts);
270
271 return 0;
272}
273
274static void ad7879_close(struct input_dev* input)
275{
276 struct ad7879 *ts = input_get_drvdata(input);
277
278 /* protected by input->mutex */
279 if (!ts->disabled && !ts->suspended)
280 __ad7879_disable(ts);
281}
282
283void ad7879_suspend(struct ad7879 *ts)
284{
285 mutex_lock(&ts->input->mutex);
286
287 if (!ts->suspended && !ts->disabled && ts->input->users)
288 __ad7879_disable(ts);
289
290 ts->suspended = true;
291
292 mutex_unlock(&ts->input->mutex);
293}
294EXPORT_SYMBOL(ad7879_suspend);
295
296void ad7879_resume(struct ad7879 *ts)
297{
298 mutex_lock(&ts->input->mutex);
299
300 if (ts->suspended && !ts->disabled && ts->input->users)
301 __ad7879_enable(ts);
302
303 ts->suspended = false;
304
305 mutex_unlock(&ts->input->mutex);
306}
307EXPORT_SYMBOL(ad7879_resume);
308
309static void ad7879_toggle(struct ad7879 *ts, bool disable)
310{
311 mutex_lock(&ts->input->mutex);
312
313 if (!ts->suspended && ts->input->users != 0) {
314
315 if (disable) {
316 if (ts->disabled)
317 __ad7879_enable(ts);
318 } else {
319 if (!ts->disabled)
320 __ad7879_disable(ts);
321 }
322 }
323
324 ts->disabled = disable;
325
326 mutex_unlock(&ts->input->mutex);
327}
328
329static ssize_t ad7879_disable_show(struct device *dev,
330 struct device_attribute *attr, char *buf)
331{
332 struct ad7879 *ts = dev_get_drvdata(dev);
333
334 return sprintf(buf, "%u\n", ts->disabled);
335}
336
337static ssize_t ad7879_disable_store(struct device *dev,
338 struct device_attribute *attr,
339 const char *buf, size_t count)
340{
341 struct ad7879 *ts = dev_get_drvdata(dev);
342 unsigned long val;
343 int error;
344
345 error = strict_strtoul(buf, 10, &val);
346 if (error)
347 return error;
348
349 ad7879_toggle(ts, val);
350
351 return count;
352}
353
354static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
355
356static struct attribute *ad7879_attributes[] = {
357 &dev_attr_disable.attr,
358 NULL
359};
360
361static const struct attribute_group ad7879_attr_group = {
362 .attrs = ad7879_attributes,
363};
364
365#ifdef CONFIG_GPIOLIB
366static int ad7879_gpio_direction_input(struct gpio_chip *chip,
367 unsigned gpio)
368{
369 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
370 int err;
371
372 mutex_lock(&ts->mutex);
373 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
374 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
375 mutex_unlock(&ts->mutex);
376
377 return err;
378}
379
380static int ad7879_gpio_direction_output(struct gpio_chip *chip,
381 unsigned gpio, int level)
382{
383 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
384 int err;
385
386 mutex_lock(&ts->mutex);
387 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
388 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
389 if (level)
390 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
391 else
392 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
393
394 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
395 mutex_unlock(&ts->mutex);
396
397 return err;
398}
399
400static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
401{
402 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
403 u16 val;
404
405 mutex_lock(&ts->mutex);
406 val = ad7879_read(ts, AD7879_REG_CTRL2);
407 mutex_unlock(&ts->mutex);
408
409 return !!(val & AD7879_GPIO_DATA);
410}
411
412static void ad7879_gpio_set_value(struct gpio_chip *chip,
413 unsigned gpio, int value)
414{
415 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
416
417 mutex_lock(&ts->mutex);
418 if (value)
419 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
420 else
421 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
422
423 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
424 mutex_unlock(&ts->mutex);
425}
426
427static int ad7879_gpio_add(struct ad7879 *ts,
428 const struct ad7879_platform_data *pdata)
429{
430 int ret = 0;
431
432 mutex_init(&ts->mutex);
433
434 if (pdata->gpio_export) {
435 ts->gc.direction_input = ad7879_gpio_direction_input;
436 ts->gc.direction_output = ad7879_gpio_direction_output;
437 ts->gc.get = ad7879_gpio_get_value;
438 ts->gc.set = ad7879_gpio_set_value;
439 ts->gc.can_sleep = 1;
440 ts->gc.base = pdata->gpio_base;
441 ts->gc.ngpio = 1;
442 ts->gc.label = "AD7879-GPIO";
443 ts->gc.owner = THIS_MODULE;
444 ts->gc.dev = ts->dev;
445
446 ret = gpiochip_add(&ts->gc);
447 if (ret)
448 dev_err(ts->dev, "failed to register gpio %d\n",
449 ts->gc.base);
450 }
451
452 return ret;
453}
454
455static void ad7879_gpio_remove(struct ad7879 *ts)
456{
457 const struct ad7879_platform_data *pdata = ts->dev->platform_data;
458 int ret;
459
460 if (pdata->gpio_export) {
461 ret = gpiochip_remove(&ts->gc);
462 if (ret)
463 dev_err(ts->dev, "failed to remove gpio %d\n",
464 ts->gc.base);
465 }
466}
467#else
468static inline int ad7879_gpio_add(struct ad7879 *ts,
469 const struct ad7879_platform_data *pdata)
470{
471 return 0;
472}
473
474static inline void ad7879_gpio_remove(struct ad7879 *ts)
475{
476}
477#endif
478
479struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
480 const struct ad7879_bus_ops *bops)
481{
482 struct ad7879_platform_data *pdata = dev->platform_data;
483 struct ad7879 *ts;
484 struct input_dev *input_dev;
485 int err;
486 u16 revid;
487
488 if (!irq) {
489 dev_err(dev, "no IRQ?\n");
490 err = -EINVAL;
491 goto err_out;
492 }
493
494 if (!pdata) {
495 dev_err(dev, "no platform data?\n");
496 err = -EINVAL;
497 goto err_out;
498 }
499
500 ts = kzalloc(sizeof(*ts), GFP_KERNEL);
501 input_dev = input_allocate_device();
502 if (!ts || !input_dev) {
503 err = -ENOMEM;
504 goto err_free_mem;
505 }
506
507 ts->bops = bops;
508 ts->dev = dev;
509 ts->input = input_dev;
510 ts->irq = irq;
511
512 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
513
514 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
515 ts->pressure_max = pdata->pressure_max ? : ~0;
516
517 ts->first_conversion_delay = pdata->first_conversion_delay;
518 ts->acquisition_time = pdata->acquisition_time;
519 ts->averaging = pdata->averaging;
520 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
521 ts->median = pdata->median;
522
523 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
524
525 input_dev->name = "AD7879 Touchscreen";
526 input_dev->phys = ts->phys;
527 input_dev->dev.parent = dev;
528 input_dev->id.bustype = bops->bustype;
529
530 input_dev->open = ad7879_open;
531 input_dev->close = ad7879_close;
532
533 input_set_drvdata(input_dev, ts);
534
535 __set_bit(EV_ABS, input_dev->evbit);
536 __set_bit(ABS_X, input_dev->absbit);
537 __set_bit(ABS_Y, input_dev->absbit);
538 __set_bit(ABS_PRESSURE, input_dev->absbit);
539
540 __set_bit(EV_KEY, input_dev->evbit);
541 __set_bit(BTN_TOUCH, input_dev->keybit);
542
543 input_set_abs_params(input_dev, ABS_X,
544 pdata->x_min ? : 0,
545 pdata->x_max ? : MAX_12BIT,
546 0, 0);
547 input_set_abs_params(input_dev, ABS_Y,
548 pdata->y_min ? : 0,
549 pdata->y_max ? : MAX_12BIT,
550 0, 0);
551 input_set_abs_params(input_dev, ABS_PRESSURE,
552 pdata->pressure_min, pdata->pressure_max, 0, 0);
553
554 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
555 if (err < 0) {
556 dev_err(dev, "Failed to write %s\n", input_dev->name);
557 goto err_free_mem;
558 }
559
560 revid = ad7879_read(ts, AD7879_REG_REVID);
561 input_dev->id.product = (revid & 0xff);
562 input_dev->id.version = revid >> 8;
563 if (input_dev->id.product != devid) {
564 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
565 input_dev->name, devid, revid);
566 err = -ENODEV;
567 goto err_free_mem;
568 }
569
570 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
571 AD7879_XPLUS_BIT |
572 AD7879_Z2_BIT |
573 AD7879_Z1_BIT |
574 AD7879_TEMPMASK_BIT |
575 AD7879_AUXVBATMASK_BIT |
576 AD7879_GPIOALERTMASK_BIT;
577
578 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
579 AD7879_AVG(ts->averaging) |
580 AD7879_MFS(ts->median) |
581 AD7879_FCD(ts->first_conversion_delay);
582
583 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
584 AD7879_ACQ(ts->acquisition_time) |
585 AD7879_TMR(ts->pen_down_acc_interval);
586
587 err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
588 IRQF_TRIGGER_FALLING,
589 dev_name(dev), ts);
590 if (err) {
591 dev_err(dev, "irq %d busy?\n", ts->irq);
592 goto err_free_mem;
593 }
594
595 __ad7879_disable(ts);
596
597 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
598 if (err)
599 goto err_free_irq;
600
601 err = ad7879_gpio_add(ts, pdata);
602 if (err)
603 goto err_remove_attr;
604
605 err = input_register_device(input_dev);
606 if (err)
607 goto err_remove_gpio;
608
609 return ts;
610
611err_remove_gpio:
612 ad7879_gpio_remove(ts);
613err_remove_attr:
614 sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
615err_free_irq:
616 free_irq(ts->irq, ts);
617err_free_mem:
618 input_free_device(input_dev);
619 kfree(ts);
620err_out:
621 return ERR_PTR(err);
622}
623EXPORT_SYMBOL(ad7879_probe);
624
625void ad7879_remove(struct ad7879 *ts)
626{
627 ad7879_gpio_remove(ts);
628 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
629 free_irq(ts->irq, ts);
630 input_unregister_device(ts->input);
631 kfree(ts);
632}
633EXPORT_SYMBOL(ad7879_remove);
634
635MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
636MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
637MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * AD7879/AD7889 based touchscreen and GPIO driver
4 *
5 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
6 *
7 * History:
8 * Copyright (c) 2005 David Brownell
9 * Copyright (c) 2006 Nokia Corporation
10 * Various changes: Imre Deak <imre.deak@nokia.com>
11 *
12 * Using code from:
13 * - corgi_ts.c
14 * Copyright (C) 2004-2005 Richard Purdie
15 * - omap_ts.[hc], ads7846.h, ts_osk.c
16 * Copyright (C) 2002 MontaVista Software
17 * Copyright (C) 2004 Texas Instruments
18 * Copyright (C) 2005 Dirk Behme
19 * - ad7877.c
20 * Copyright (C) 2006-2008 Analog Devices Inc.
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/* Control REG 1 */
54#define AD7879_TMR(x) ((x & 0xFF) << 0)
55#define AD7879_ACQ(x) ((x & 0x3) << 8)
56#define AD7879_MODE_NOC (0 << 10) /* Do not convert */
57#define AD7879_MODE_SCC (1 << 10) /* Single channel conversion */
58#define AD7879_MODE_SEQ0 (2 << 10) /* Sequence 0 in Slave Mode */
59#define AD7879_MODE_SEQ1 (3 << 10) /* Sequence 1 in Master Mode */
60#define AD7879_MODE_INT (1 << 15) /* PENIRQ disabled INT enabled */
61
62/* Control REG 2 */
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) /* non-differential */
68#define AD7879_DFR (0 << 9) /* differential */
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/* Control REG 3 */
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; /* P: input->mutex */
117 bool suspended; /* P: input->mutex */
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 * The samples processed here are already preprocessed by the AD7879.
181 * The preprocessing function consists of a median and an averaging
182 * filter. The combination of these two techniques provides a robust
183 * solution, discarding the spurious noise in the signal and keeping
184 * only the data of interest. The size of both filters is
185 * programmable. (dev.platform_data, see linux/platform_data/ad7879.h)
186 * Other user-programmable conversion controls include variable
187 * acquisition time, and first conversion delay. Up to 16 averages can
188 * be taken per conversion.
189 */
190
191 if (likely(x && z1)) {
192 /* compute touch pressure resistance using equation #1 */
193 Rt = (z2 - z1) * x * ts->x_plate_ohms;
194 Rt /= z1;
195 Rt = (Rt + 2047) >> 12;
196
197 /*
198 * Sample found inconsistent, pressure is beyond
199 * the maximum. Don't report it to user space.
200 */
201 if (Rt > input_abs_get_max(input_dev, ABS_PRESSURE))
202 return -EINVAL;
203
204 /*
205 * Note that we delay reporting events by one sample.
206 * This is done to avoid reporting last sample of the
207 * touch sequence, which may be incomplete if finger
208 * leaves the surface before last reading is taken.
209 */
210 if (timer_pending(&ts->timer)) {
211 /* Touch continues */
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 /* protected by input->mutex */
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 /* protected by input->mutex */
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
394const struct attribute_group *ad7879_groups[] = {
395 &ad7879_attr_group,
396 NULL
397};
398EXPORT_SYMBOL_GPL(ad7879_groups);
399
400#ifdef CONFIG_GPIOLIB
401static int ad7879_gpio_direction_input(struct gpio_chip *chip,
402 unsigned gpio)
403{
404 struct ad7879 *ts = gpiochip_get_data(chip);
405 int err;
406
407 mutex_lock(&ts->mutex);
408 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
409 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
410 mutex_unlock(&ts->mutex);
411
412 return err;
413}
414
415static int ad7879_gpio_direction_output(struct gpio_chip *chip,
416 unsigned gpio, int level)
417{
418 struct ad7879 *ts = gpiochip_get_data(chip);
419 int err;
420
421 mutex_lock(&ts->mutex);
422 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
423 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
424 if (level)
425 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
426 else
427 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
428
429 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
430 mutex_unlock(&ts->mutex);
431
432 return err;
433}
434
435static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
436{
437 struct ad7879 *ts = gpiochip_get_data(chip);
438 u16 val;
439
440 mutex_lock(&ts->mutex);
441 val = ad7879_read(ts, AD7879_REG_CTRL2);
442 mutex_unlock(&ts->mutex);
443
444 return !!(val & AD7879_GPIO_DATA);
445}
446
447static void ad7879_gpio_set_value(struct gpio_chip *chip,
448 unsigned gpio, int value)
449{
450 struct ad7879 *ts = gpiochip_get_data(chip);
451
452 mutex_lock(&ts->mutex);
453 if (value)
454 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
455 else
456 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
457
458 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
459 mutex_unlock(&ts->mutex);
460}
461
462static int ad7879_gpio_add(struct ad7879 *ts)
463{
464 int ret = 0;
465
466 mutex_init(&ts->mutex);
467
468 /* Do not create a chip unless flagged for it */
469 if (!device_property_read_bool(ts->dev, "gpio-controller"))
470 return 0;
471
472 ts->gc.direction_input = ad7879_gpio_direction_input;
473 ts->gc.direction_output = ad7879_gpio_direction_output;
474 ts->gc.get = ad7879_gpio_get_value;
475 ts->gc.set = ad7879_gpio_set_value;
476 ts->gc.can_sleep = 1;
477 ts->gc.base = -1;
478 ts->gc.ngpio = 1;
479 ts->gc.label = "AD7879-GPIO";
480 ts->gc.owner = THIS_MODULE;
481 ts->gc.parent = ts->dev;
482
483 ret = devm_gpiochip_add_data(ts->dev, &ts->gc, ts);
484 if (ret)
485 dev_err(ts->dev, "failed to register gpio %d\n",
486 ts->gc.base);
487
488 return ret;
489}
490#else
491static int ad7879_gpio_add(struct ad7879 *ts)
492{
493 return 0;
494}
495#endif
496
497static int ad7879_parse_dt(struct device *dev, struct ad7879 *ts)
498{
499 int err;
500 u32 tmp;
501
502 err = device_property_read_u32(dev, "adi,resistance-plate-x", &tmp);
503 if (err) {
504 dev_err(dev, "failed to get resistance-plate-x property\n");
505 return err;
506 }
507 ts->x_plate_ohms = (u16)tmp;
508
509 device_property_read_u8(dev, "adi,first-conversion-delay",
510 &ts->first_conversion_delay);
511 device_property_read_u8(dev, "adi,acquisition-time",
512 &ts->acquisition_time);
513 device_property_read_u8(dev, "adi,median-filter-size", &ts->median);
514 device_property_read_u8(dev, "adi,averaging", &ts->averaging);
515 device_property_read_u8(dev, "adi,conversion-interval",
516 &ts->pen_down_acc_interval);
517
518 ts->swap_xy = device_property_read_bool(dev, "touchscreen-swapped-x-y");
519
520 return 0;
521}
522
523int ad7879_probe(struct device *dev, struct regmap *regmap,
524 int irq, u16 bustype, u8 devid)
525{
526 struct ad7879 *ts;
527 struct input_dev *input_dev;
528 int err;
529 u16 revid;
530
531 if (irq <= 0) {
532 dev_err(dev, "No IRQ specified\n");
533 return -EINVAL;
534 }
535
536 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
537 if (!ts)
538 return -ENOMEM;
539
540 err = ad7879_parse_dt(dev, ts);
541 if (err)
542 return err;
543
544 input_dev = devm_input_allocate_device(dev);
545 if (!input_dev) {
546 dev_err(dev, "Failed to allocate input device\n");
547 return -ENOMEM;
548 }
549
550 ts->dev = dev;
551 ts->input = input_dev;
552 ts->irq = irq;
553 ts->regmap = regmap;
554
555 timer_setup(&ts->timer, ad7879_timer, 0);
556 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
557
558 input_dev->name = "AD7879 Touchscreen";
559 input_dev->phys = ts->phys;
560 input_dev->dev.parent = dev;
561 input_dev->id.bustype = bustype;
562
563 input_dev->open = ad7879_open;
564 input_dev->close = ad7879_close;
565
566 input_set_drvdata(input_dev, ts);
567
568 input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
569
570 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
571 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
572 input_set_capability(input_dev, EV_ABS, ABS_PRESSURE);
573 touchscreen_parse_properties(input_dev, false, NULL);
574 if (!input_abs_get_max(input_dev, ABS_PRESSURE)) {
575 dev_err(dev, "Touchscreen pressure is not specified\n");
576 return -EINVAL;
577 }
578
579 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
580 if (err < 0) {
581 dev_err(dev, "Failed to write %s\n", input_dev->name);
582 return err;
583 }
584
585 revid = ad7879_read(ts, AD7879_REG_REVID);
586 input_dev->id.product = (revid & 0xff);
587 input_dev->id.version = revid >> 8;
588 if (input_dev->id.product != devid) {
589 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
590 input_dev->name, devid, revid);
591 return -ENODEV;
592 }
593
594 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
595 AD7879_XPLUS_BIT |
596 AD7879_Z2_BIT |
597 AD7879_Z1_BIT |
598 AD7879_TEMPMASK_BIT |
599 AD7879_AUXVBATMASK_BIT |
600 AD7879_GPIOALERTMASK_BIT;
601
602 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
603 AD7879_AVG(ts->averaging) |
604 AD7879_MFS(ts->median) |
605 AD7879_FCD(ts->first_conversion_delay);
606
607 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
608 AD7879_ACQ(ts->acquisition_time) |
609 AD7879_TMR(ts->pen_down_acc_interval);
610
611 err = devm_request_threaded_irq(dev, ts->irq, NULL, ad7879_irq,
612 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
613 dev_name(dev), ts);
614 if (err) {
615 dev_err(dev, "Failed to request IRQ: %d\n", err);
616 return err;
617 }
618
619 __ad7879_disable(ts);
620
621 err = ad7879_gpio_add(ts);
622 if (err)
623 return err;
624
625 err = input_register_device(input_dev);
626 if (err)
627 return err;
628
629 dev_set_drvdata(dev, ts);
630
631 return 0;
632}
633EXPORT_SYMBOL(ad7879_probe);
634
635MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
636MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
637MODULE_LICENSE("GPL");