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/slab.h>
30 #include <linux/spi/spi.h>
31 #include <linux/i2c.h>
32 #include <linux/gpio.h>
34 #include <linux/input/touchscreen.h>
35 #include <linux/platform_data/ad7879.h>
36 #include <linux/module.h>
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
56 #define AD7879_TMR(x) ((x & 0xFF) << 0)
57 #define AD7879_ACQ(x) ((x & 0x3) << 8)
58 #define AD7879_MODE_NOC (0 << 10) /* Do not convert */
59 #define AD7879_MODE_SCC (1 << 10) /* Single channel conversion */
60 #define AD7879_MODE_SEQ0 (2 << 10) /* Sequence 0 in Slave Mode */
61 #define AD7879_MODE_SEQ1 (3 << 10) /* Sequence 1 in Master Mode */
62 #define AD7879_MODE_INT (1 << 15) /* PENIRQ disabled INT enabled */
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) /* non-differential */
70 #define AD7879_DFR (0 << 9) /* differential */
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)
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)
105 #define MAX_12BIT ((1<<12)-1)
106 #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)
109 const struct ad7879_bus_ops *bops;
112 struct input_dev *input;
113 struct timer_list timer;
114 #ifdef CONFIG_GPIOLIB
119 bool disabled; /* P: input->mutex */
120 bool suspended; /* P: input->mutex */
122 u16 conversion_data[AD7879_NR_SENSE];
124 u8 first_conversion_delay;
127 u8 pen_down_acc_interval;
138 static int ad7879_read(struct ad7879 *ts, u8 reg)
140 return ts->bops->read(ts->dev, reg);
143 static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
145 return ts->bops->multi_read(ts->dev, first_reg, count, buf);
148 static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
150 return ts->bops->write(ts->dev, reg, val);
153 static int ad7879_report(struct ad7879 *ts)
155 struct input_dev *input_dev = ts->input;
159 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
160 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
161 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
162 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
168 * The samples processed here are already preprocessed by the AD7879.
169 * The preprocessing function consists of a median and an averaging
170 * filter. The combination of these two techniques provides a robust
171 * solution, discarding the spurious noise in the signal and keeping
172 * only the data of interest. The size of both filters is
173 * programmable. (dev.platform_data, see linux/platform_data/ad7879.h)
174 * Other user-programmable conversion controls include variable
175 * acquisition time, and first conversion delay. Up to 16 averages can
176 * be taken per conversion.
179 if (likely(x && z1)) {
180 /* compute touch pressure resistance using equation #1 */
181 Rt = (z2 - z1) * x * ts->x_plate_ohms;
183 Rt = (Rt + 2047) >> 12;
186 * Sample found inconsistent, pressure is beyond
187 * the maximum. Don't report it to user space.
189 if (Rt > input_abs_get_max(input_dev, ABS_PRESSURE))
193 * Note that we delay reporting events by one sample.
194 * This is done to avoid reporting last sample of the
195 * touch sequence, which may be incomplete if finger
196 * leaves the surface before last reading is taken.
198 if (timer_pending(&ts->timer)) {
199 /* Touch continues */
200 input_report_key(input_dev, BTN_TOUCH, 1);
201 input_report_abs(input_dev, ABS_X, ts->x);
202 input_report_abs(input_dev, ABS_Y, ts->y);
203 input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
204 input_sync(input_dev);
217 static void ad7879_ts_event_release(struct ad7879 *ts)
219 struct input_dev *input_dev = ts->input;
221 input_report_abs(input_dev, ABS_PRESSURE, 0);
222 input_report_key(input_dev, BTN_TOUCH, 0);
223 input_sync(input_dev);
226 static void ad7879_timer(unsigned long handle)
228 struct ad7879 *ts = (void *)handle;
230 ad7879_ts_event_release(ts);
233 static irqreturn_t ad7879_irq(int irq, void *handle)
235 struct ad7879 *ts = handle;
237 ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
239 if (!ad7879_report(ts))
240 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
245 static void __ad7879_enable(struct ad7879 *ts)
247 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
248 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
249 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
254 static void __ad7879_disable(struct ad7879 *ts)
256 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
257 AD7879_PM(AD7879_PM_SHUTDOWN);
258 disable_irq(ts->irq);
260 if (del_timer_sync(&ts->timer))
261 ad7879_ts_event_release(ts);
263 ad7879_write(ts, AD7879_REG_CTRL2, reg);
267 static int ad7879_open(struct input_dev *input)
269 struct ad7879 *ts = input_get_drvdata(input);
271 /* protected by input->mutex */
272 if (!ts->disabled && !ts->suspended)
278 static void ad7879_close(struct input_dev* input)
280 struct ad7879 *ts = input_get_drvdata(input);
282 /* protected by input->mutex */
283 if (!ts->disabled && !ts->suspended)
284 __ad7879_disable(ts);
287 static int __maybe_unused ad7879_suspend(struct device *dev)
289 struct ad7879 *ts = dev_get_drvdata(dev);
291 mutex_lock(&ts->input->mutex);
293 if (!ts->suspended && !ts->disabled && ts->input->users)
294 __ad7879_disable(ts);
296 ts->suspended = true;
298 mutex_unlock(&ts->input->mutex);
303 static int __maybe_unused ad7879_resume(struct device *dev)
305 struct ad7879 *ts = dev_get_drvdata(dev);
307 mutex_lock(&ts->input->mutex);
309 if (ts->suspended && !ts->disabled && ts->input->users)
312 ts->suspended = false;
314 mutex_unlock(&ts->input->mutex);
319 SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
320 EXPORT_SYMBOL(ad7879_pm_ops);
322 static void ad7879_toggle(struct ad7879 *ts, bool disable)
324 mutex_lock(&ts->input->mutex);
326 if (!ts->suspended && ts->input->users != 0) {
333 __ad7879_disable(ts);
337 ts->disabled = disable;
339 mutex_unlock(&ts->input->mutex);
342 static ssize_t ad7879_disable_show(struct device *dev,
343 struct device_attribute *attr, char *buf)
345 struct ad7879 *ts = dev_get_drvdata(dev);
347 return sprintf(buf, "%u\n", ts->disabled);
350 static ssize_t ad7879_disable_store(struct device *dev,
351 struct device_attribute *attr,
352 const char *buf, size_t count)
354 struct ad7879 *ts = dev_get_drvdata(dev);
358 error = kstrtouint(buf, 10, &val);
362 ad7879_toggle(ts, val);
367 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
369 static struct attribute *ad7879_attributes[] = {
370 &dev_attr_disable.attr,
374 static const struct attribute_group ad7879_attr_group = {
375 .attrs = ad7879_attributes,
378 #ifdef CONFIG_GPIOLIB
379 static int ad7879_gpio_direction_input(struct gpio_chip *chip,
382 struct ad7879 *ts = gpiochip_get_data(chip);
385 mutex_lock(&ts->mutex);
386 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
387 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
388 mutex_unlock(&ts->mutex);
393 static int ad7879_gpio_direction_output(struct gpio_chip *chip,
394 unsigned gpio, int level)
396 struct ad7879 *ts = gpiochip_get_data(chip);
399 mutex_lock(&ts->mutex);
400 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
401 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
403 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
405 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
407 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
408 mutex_unlock(&ts->mutex);
413 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
415 struct ad7879 *ts = gpiochip_get_data(chip);
418 mutex_lock(&ts->mutex);
419 val = ad7879_read(ts, AD7879_REG_CTRL2);
420 mutex_unlock(&ts->mutex);
422 return !!(val & AD7879_GPIO_DATA);
425 static void ad7879_gpio_set_value(struct gpio_chip *chip,
426 unsigned gpio, int value)
428 struct ad7879 *ts = gpiochip_get_data(chip);
430 mutex_lock(&ts->mutex);
432 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
434 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
436 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
437 mutex_unlock(&ts->mutex);
440 static int ad7879_gpio_add(struct ad7879 *ts,
441 const struct ad7879_platform_data *pdata)
445 mutex_init(&ts->mutex);
447 if (pdata->gpio_export) {
448 ts->gc.direction_input = ad7879_gpio_direction_input;
449 ts->gc.direction_output = ad7879_gpio_direction_output;
450 ts->gc.get = ad7879_gpio_get_value;
451 ts->gc.set = ad7879_gpio_set_value;
452 ts->gc.can_sleep = 1;
453 ts->gc.base = pdata->gpio_base;
455 ts->gc.label = "AD7879-GPIO";
456 ts->gc.owner = THIS_MODULE;
457 ts->gc.parent = ts->dev;
459 ret = gpiochip_add_data(&ts->gc, ts);
461 dev_err(ts->dev, "failed to register gpio %d\n",
468 static void ad7879_gpio_remove(struct ad7879 *ts)
470 const struct ad7879_platform_data *pdata = dev_get_platdata(ts->dev);
472 if (pdata && pdata->gpio_export)
473 gpiochip_remove(&ts->gc);
477 static inline int ad7879_gpio_add(struct ad7879 *ts,
478 const struct ad7879_platform_data *pdata)
483 static inline void ad7879_gpio_remove(struct ad7879 *ts)
488 static int ad7879_parse_dt(struct device *dev, struct ad7879 *ts)
493 err = device_property_read_u32(dev, "adi,resistance-plate-x", &tmp);
495 dev_err(dev, "failed to get resistance-plate-x property\n");
498 ts->x_plate_ohms = (u16)tmp;
500 device_property_read_u8(dev, "adi,first-conversion-delay",
501 &ts->first_conversion_delay);
502 device_property_read_u8(dev, "adi,acquisition-time",
503 &ts->acquisition_time);
504 device_property_read_u8(dev, "adi,median-filter-size", &ts->median);
505 device_property_read_u8(dev, "adi,averaging", &ts->averaging);
506 device_property_read_u8(dev, "adi,conversion-interval",
507 &ts->pen_down_acc_interval);
509 ts->swap_xy = device_property_read_bool(dev, "touchscreen-swapped-x-y");
514 struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
515 const struct ad7879_bus_ops *bops)
517 struct ad7879_platform_data *pdata = dev_get_platdata(dev);
519 struct input_dev *input_dev;
524 dev_err(dev, "No IRQ specified\n");
525 return ERR_PTR(-EINVAL);
528 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
530 return ERR_PTR(-ENOMEM);
533 /* Platform data use swapped axis (backward compatibility) */
534 ts->swap_xy = !pdata->swap_xy;
536 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
538 ts->first_conversion_delay = pdata->first_conversion_delay;
539 ts->acquisition_time = pdata->acquisition_time;
540 ts->averaging = pdata->averaging;
541 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
542 ts->median = pdata->median;
543 } else if (dev->of_node) {
544 ad7879_parse_dt(dev, ts);
546 dev_err(dev, "No platform data\n");
547 return ERR_PTR(-EINVAL);
550 input_dev = devm_input_allocate_device(dev);
552 dev_err(dev, "Failed to allocate input device\n");
553 return ERR_PTR(-ENOMEM);
558 ts->input = input_dev;
561 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
562 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
564 input_dev->name = "AD7879 Touchscreen";
565 input_dev->phys = ts->phys;
566 input_dev->dev.parent = dev;
567 input_dev->id.bustype = bops->bustype;
569 input_dev->open = ad7879_open;
570 input_dev->close = ad7879_close;
572 input_set_drvdata(input_dev, ts);
574 __set_bit(EV_ABS, input_dev->evbit);
575 __set_bit(ABS_X, input_dev->absbit);
576 __set_bit(ABS_Y, input_dev->absbit);
577 __set_bit(ABS_PRESSURE, input_dev->absbit);
579 __set_bit(EV_KEY, input_dev->evbit);
580 __set_bit(BTN_TOUCH, input_dev->keybit);
583 input_set_abs_params(input_dev, ABS_X,
585 pdata->x_max ? : MAX_12BIT,
587 input_set_abs_params(input_dev, ABS_Y,
589 pdata->y_max ? : MAX_12BIT,
591 input_set_abs_params(input_dev, ABS_PRESSURE,
593 pdata->pressure_max ? : ~0,
596 input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
597 input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
598 touchscreen_parse_properties(input_dev, false, NULL);
599 if (!input_abs_get_max(input_dev, ABS_PRESSURE)) {
600 dev_err(dev, "Touchscreen pressure is not specified\n");
601 return ERR_PTR(-EINVAL);
605 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
607 dev_err(dev, "Failed to write %s\n", input_dev->name);
611 revid = ad7879_read(ts, AD7879_REG_REVID);
612 input_dev->id.product = (revid & 0xff);
613 input_dev->id.version = revid >> 8;
614 if (input_dev->id.product != devid) {
615 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
616 input_dev->name, devid, revid);
617 return ERR_PTR(-ENODEV);
620 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
624 AD7879_TEMPMASK_BIT |
625 AD7879_AUXVBATMASK_BIT |
626 AD7879_GPIOALERTMASK_BIT;
628 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
629 AD7879_AVG(ts->averaging) |
630 AD7879_MFS(ts->median) |
631 AD7879_FCD(ts->first_conversion_delay);
633 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
634 AD7879_ACQ(ts->acquisition_time) |
635 AD7879_TMR(ts->pen_down_acc_interval);
637 err = devm_request_threaded_irq(dev, ts->irq, NULL, ad7879_irq,
638 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
641 dev_err(dev, "Failed to request IRQ: %d\n", err);
645 __ad7879_disable(ts);
647 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
652 err = ad7879_gpio_add(ts, pdata);
654 goto err_remove_attr;
657 err = input_register_device(input_dev);
659 goto err_remove_gpio;
664 ad7879_gpio_remove(ts);
666 sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
670 EXPORT_SYMBOL(ad7879_probe);
672 void ad7879_remove(struct ad7879 *ts)
674 ad7879_gpio_remove(ts);
675 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
677 EXPORT_SYMBOL(ad7879_remove);
679 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
680 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
681 MODULE_LICENSE("GPL");