2 * AD7879/AD7889 based touchscreen and GPIO driver
4 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
6 * Licensed under the GPL-2 or later.
9 * Copyright (c) 2005 David Brownell
10 * Copyright (c) 2006 Nokia Corporation
11 * Various changes: Imre Deak <imre.deak@nokia.com>
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
21 * Copyright (C) 2006-2008 Analog Devices Inc.
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/driver.h>
34 #include <linux/input/touchscreen.h>
35 #include <linux/module.h>
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
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 */
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)
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)
104 #define MAX_12BIT ((1<<12)-1)
105 #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)
108 struct regmap *regmap;
110 struct input_dev *input;
111 struct timer_list timer;
112 #ifdef CONFIG_GPIOLIB
117 bool disabled; /* P: input->mutex */
118 bool suspended; /* P: input->mutex */
120 u16 conversion_data[AD7879_NR_SENSE];
122 u8 first_conversion_delay;
125 u8 pen_down_acc_interval;
136 static int ad7879_read(struct ad7879 *ts, u8 reg)
141 error = regmap_read(ts->regmap, reg, &val);
143 dev_err(ts->dev, "failed to read register %#02x: %d\n",
151 static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
155 error = regmap_write(ts->regmap, reg, val);
158 "failed to write %#04x to register %#02x: %d\n",
166 static int ad7879_report(struct ad7879 *ts)
168 struct input_dev *input_dev = ts->input;
172 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
173 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
174 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
175 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
181 * The samples processed here are already preprocessed by the AD7879.
182 * The preprocessing function consists of a median and an averaging
183 * filter. The combination of these two techniques provides a robust
184 * solution, discarding the spurious noise in the signal and keeping
185 * only the data of interest. The size of both filters is
186 * programmable. (dev.platform_data, see linux/platform_data/ad7879.h)
187 * Other user-programmable conversion controls include variable
188 * acquisition time, and first conversion delay. Up to 16 averages can
189 * be taken per conversion.
192 if (likely(x && z1)) {
193 /* compute touch pressure resistance using equation #1 */
194 Rt = (z2 - z1) * x * ts->x_plate_ohms;
196 Rt = (Rt + 2047) >> 12;
199 * Sample found inconsistent, pressure is beyond
200 * the maximum. Don't report it to user space.
202 if (Rt > input_abs_get_max(input_dev, ABS_PRESSURE))
206 * Note that we delay reporting events by one sample.
207 * This is done to avoid reporting last sample of the
208 * touch sequence, which may be incomplete if finger
209 * leaves the surface before last reading is taken.
211 if (timer_pending(&ts->timer)) {
212 /* Touch continues */
213 input_report_key(input_dev, BTN_TOUCH, 1);
214 input_report_abs(input_dev, ABS_X, ts->x);
215 input_report_abs(input_dev, ABS_Y, ts->y);
216 input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
217 input_sync(input_dev);
230 static void ad7879_ts_event_release(struct ad7879 *ts)
232 struct input_dev *input_dev = ts->input;
234 input_report_abs(input_dev, ABS_PRESSURE, 0);
235 input_report_key(input_dev, BTN_TOUCH, 0);
236 input_sync(input_dev);
239 static void ad7879_timer(struct timer_list *t)
241 struct ad7879 *ts = from_timer(ts, t, timer);
243 ad7879_ts_event_release(ts);
246 static irqreturn_t ad7879_irq(int irq, void *handle)
248 struct ad7879 *ts = handle;
251 error = regmap_bulk_read(ts->regmap, AD7879_REG_XPLUS,
252 ts->conversion_data, AD7879_NR_SENSE);
254 dev_err_ratelimited(ts->dev, "failed to read %#02x: %d\n",
255 AD7879_REG_XPLUS, error);
256 else if (!ad7879_report(ts))
257 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
262 static void __ad7879_enable(struct ad7879 *ts)
264 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
265 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
266 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
271 static void __ad7879_disable(struct ad7879 *ts)
273 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
274 AD7879_PM(AD7879_PM_SHUTDOWN);
275 disable_irq(ts->irq);
277 if (del_timer_sync(&ts->timer))
278 ad7879_ts_event_release(ts);
280 ad7879_write(ts, AD7879_REG_CTRL2, reg);
284 static int ad7879_open(struct input_dev *input)
286 struct ad7879 *ts = input_get_drvdata(input);
288 /* protected by input->mutex */
289 if (!ts->disabled && !ts->suspended)
295 static void ad7879_close(struct input_dev *input)
297 struct ad7879 *ts = input_get_drvdata(input);
299 /* protected by input->mutex */
300 if (!ts->disabled && !ts->suspended)
301 __ad7879_disable(ts);
304 static int __maybe_unused ad7879_suspend(struct device *dev)
306 struct ad7879 *ts = dev_get_drvdata(dev);
308 mutex_lock(&ts->input->mutex);
310 if (!ts->suspended && !ts->disabled && ts->input->users)
311 __ad7879_disable(ts);
313 ts->suspended = true;
315 mutex_unlock(&ts->input->mutex);
320 static int __maybe_unused ad7879_resume(struct device *dev)
322 struct ad7879 *ts = dev_get_drvdata(dev);
324 mutex_lock(&ts->input->mutex);
326 if (ts->suspended && !ts->disabled && ts->input->users)
329 ts->suspended = false;
331 mutex_unlock(&ts->input->mutex);
336 SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
337 EXPORT_SYMBOL(ad7879_pm_ops);
339 static void ad7879_toggle(struct ad7879 *ts, bool disable)
341 mutex_lock(&ts->input->mutex);
343 if (!ts->suspended && ts->input->users != 0) {
350 __ad7879_disable(ts);
354 ts->disabled = disable;
356 mutex_unlock(&ts->input->mutex);
359 static ssize_t ad7879_disable_show(struct device *dev,
360 struct device_attribute *attr, char *buf)
362 struct ad7879 *ts = dev_get_drvdata(dev);
364 return sprintf(buf, "%u\n", ts->disabled);
367 static ssize_t ad7879_disable_store(struct device *dev,
368 struct device_attribute *attr,
369 const char *buf, size_t count)
371 struct ad7879 *ts = dev_get_drvdata(dev);
375 error = kstrtouint(buf, 10, &val);
379 ad7879_toggle(ts, val);
384 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
386 static struct attribute *ad7879_attributes[] = {
387 &dev_attr_disable.attr,
391 static const struct attribute_group ad7879_attr_group = {
392 .attrs = ad7879_attributes,
395 #ifdef CONFIG_GPIOLIB
396 static int ad7879_gpio_direction_input(struct gpio_chip *chip,
399 struct ad7879 *ts = gpiochip_get_data(chip);
402 mutex_lock(&ts->mutex);
403 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
404 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
405 mutex_unlock(&ts->mutex);
410 static int ad7879_gpio_direction_output(struct gpio_chip *chip,
411 unsigned gpio, int level)
413 struct ad7879 *ts = gpiochip_get_data(chip);
416 mutex_lock(&ts->mutex);
417 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
418 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
420 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
422 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
424 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
425 mutex_unlock(&ts->mutex);
430 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
432 struct ad7879 *ts = gpiochip_get_data(chip);
435 mutex_lock(&ts->mutex);
436 val = ad7879_read(ts, AD7879_REG_CTRL2);
437 mutex_unlock(&ts->mutex);
439 return !!(val & AD7879_GPIO_DATA);
442 static void ad7879_gpio_set_value(struct gpio_chip *chip,
443 unsigned gpio, int value)
445 struct ad7879 *ts = gpiochip_get_data(chip);
447 mutex_lock(&ts->mutex);
449 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
451 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
453 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
454 mutex_unlock(&ts->mutex);
457 static int ad7879_gpio_add(struct ad7879 *ts)
461 mutex_init(&ts->mutex);
463 /* Do not create a chip unless flagged for it */
464 if (!device_property_read_bool(ts->dev, "gpio-controller"))
467 ts->gc.direction_input = ad7879_gpio_direction_input;
468 ts->gc.direction_output = ad7879_gpio_direction_output;
469 ts->gc.get = ad7879_gpio_get_value;
470 ts->gc.set = ad7879_gpio_set_value;
471 ts->gc.can_sleep = 1;
474 ts->gc.label = "AD7879-GPIO";
475 ts->gc.owner = THIS_MODULE;
476 ts->gc.parent = ts->dev;
478 ret = devm_gpiochip_add_data(ts->dev, &ts->gc, ts);
480 dev_err(ts->dev, "failed to register gpio %d\n",
486 static int ad7879_gpio_add(struct ad7879 *ts)
492 static int ad7879_parse_dt(struct device *dev, struct ad7879 *ts)
497 err = device_property_read_u32(dev, "adi,resistance-plate-x", &tmp);
499 dev_err(dev, "failed to get resistance-plate-x property\n");
502 ts->x_plate_ohms = (u16)tmp;
504 device_property_read_u8(dev, "adi,first-conversion-delay",
505 &ts->first_conversion_delay);
506 device_property_read_u8(dev, "adi,acquisition-time",
507 &ts->acquisition_time);
508 device_property_read_u8(dev, "adi,median-filter-size", &ts->median);
509 device_property_read_u8(dev, "adi,averaging", &ts->averaging);
510 device_property_read_u8(dev, "adi,conversion-interval",
511 &ts->pen_down_acc_interval);
513 ts->swap_xy = device_property_read_bool(dev, "touchscreen-swapped-x-y");
518 int ad7879_probe(struct device *dev, struct regmap *regmap,
519 int irq, u16 bustype, u8 devid)
522 struct input_dev *input_dev;
527 dev_err(dev, "No IRQ specified\n");
531 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
535 err = ad7879_parse_dt(dev, ts);
539 input_dev = devm_input_allocate_device(dev);
541 dev_err(dev, "Failed to allocate input device\n");
546 ts->input = input_dev;
550 timer_setup(&ts->timer, ad7879_timer, 0);
551 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
553 input_dev->name = "AD7879 Touchscreen";
554 input_dev->phys = ts->phys;
555 input_dev->dev.parent = dev;
556 input_dev->id.bustype = bustype;
558 input_dev->open = ad7879_open;
559 input_dev->close = ad7879_close;
561 input_set_drvdata(input_dev, ts);
563 input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
565 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
566 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
567 input_set_capability(input_dev, EV_ABS, ABS_PRESSURE);
568 touchscreen_parse_properties(input_dev, false, NULL);
569 if (!input_abs_get_max(input_dev, ABS_PRESSURE)) {
570 dev_err(dev, "Touchscreen pressure is not specified\n");
574 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
576 dev_err(dev, "Failed to write %s\n", input_dev->name);
580 revid = ad7879_read(ts, AD7879_REG_REVID);
581 input_dev->id.product = (revid & 0xff);
582 input_dev->id.version = revid >> 8;
583 if (input_dev->id.product != devid) {
584 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
585 input_dev->name, devid, revid);
589 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
593 AD7879_TEMPMASK_BIT |
594 AD7879_AUXVBATMASK_BIT |
595 AD7879_GPIOALERTMASK_BIT;
597 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
598 AD7879_AVG(ts->averaging) |
599 AD7879_MFS(ts->median) |
600 AD7879_FCD(ts->first_conversion_delay);
602 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
603 AD7879_ACQ(ts->acquisition_time) |
604 AD7879_TMR(ts->pen_down_acc_interval);
606 err = devm_request_threaded_irq(dev, ts->irq, NULL, ad7879_irq,
607 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
610 dev_err(dev, "Failed to request IRQ: %d\n", err);
614 __ad7879_disable(ts);
616 err = devm_device_add_group(dev, &ad7879_attr_group);
620 err = ad7879_gpio_add(ts);
624 err = input_register_device(input_dev);
628 dev_set_drvdata(dev, ts);
632 EXPORT_SYMBOL(ad7879_probe);
634 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
635 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
636 MODULE_LICENSE("GPL");