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.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 struct regmap
*regmap
;
111 struct input_dev
*input
;
112 struct timer_list timer
;
113 #ifdef CONFIG_GPIOLIB
118 bool disabled
; /* P: input->mutex */
119 bool suspended
; /* P: input->mutex */
121 u16 conversion_data
[AD7879_NR_SENSE
];
123 u8 first_conversion_delay
;
126 u8 pen_down_acc_interval
;
137 static int ad7879_read(struct ad7879
*ts
, u8 reg
)
142 error
= regmap_read(ts
->regmap
, reg
, &val
);
144 dev_err(ts
->dev
, "failed to read register %#02x: %d\n",
152 static int ad7879_write(struct ad7879
*ts
, u8 reg
, u16 val
)
156 error
= regmap_write(ts
->regmap
, reg
, val
);
159 "failed to write %#04x to register %#02x: %d\n",
167 static int ad7879_report(struct ad7879
*ts
)
169 struct input_dev
*input_dev
= ts
->input
;
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
;
182 * The samples processed here are already preprocessed by the AD7879.
183 * The preprocessing function consists of a median and an averaging
184 * filter. The combination of these two techniques provides a robust
185 * solution, discarding the spurious noise in the signal and keeping
186 * only the data of interest. The size of both filters is
187 * programmable. (dev.platform_data, see linux/platform_data/ad7879.h)
188 * Other user-programmable conversion controls include variable
189 * acquisition time, and first conversion delay. Up to 16 averages can
190 * be taken per conversion.
193 if (likely(x
&& z1
)) {
194 /* compute touch pressure resistance using equation #1 */
195 Rt
= (z2
- z1
) * x
* ts
->x_plate_ohms
;
197 Rt
= (Rt
+ 2047) >> 12;
200 * Sample found inconsistent, pressure is beyond
201 * the maximum. Don't report it to user space.
203 if (Rt
> input_abs_get_max(input_dev
, ABS_PRESSURE
))
207 * Note that we delay reporting events by one sample.
208 * This is done to avoid reporting last sample of the
209 * touch sequence, which may be incomplete if finger
210 * leaves the surface before last reading is taken.
212 if (timer_pending(&ts
->timer
)) {
213 /* Touch continues */
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
);
231 static void ad7879_ts_event_release(struct ad7879
*ts
)
233 struct input_dev
*input_dev
= ts
->input
;
235 input_report_abs(input_dev
, ABS_PRESSURE
, 0);
236 input_report_key(input_dev
, BTN_TOUCH
, 0);
237 input_sync(input_dev
);
240 static void ad7879_timer(unsigned long handle
)
242 struct ad7879
*ts
= (void *)handle
;
244 ad7879_ts_event_release(ts
);
247 static irqreturn_t
ad7879_irq(int irq
, void *handle
)
249 struct ad7879
*ts
= handle
;
251 regmap_bulk_read(ts
->regmap
, AD7879_REG_XPLUS
,
252 ts
->conversion_data
, AD7879_NR_SENSE
);
254 if (!ad7879_report(ts
))
255 mod_timer(&ts
->timer
, jiffies
+ TS_PEN_UP_TIMEOUT
);
260 static void __ad7879_enable(struct ad7879
*ts
)
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
);
269 static void __ad7879_disable(struct ad7879
*ts
)
271 u16 reg
= (ts
->cmd_crtl2
& ~AD7879_PM(-1)) |
272 AD7879_PM(AD7879_PM_SHUTDOWN
);
273 disable_irq(ts
->irq
);
275 if (del_timer_sync(&ts
->timer
))
276 ad7879_ts_event_release(ts
);
278 ad7879_write(ts
, AD7879_REG_CTRL2
, reg
);
282 static int ad7879_open(struct input_dev
*input
)
284 struct ad7879
*ts
= input_get_drvdata(input
);
286 /* protected by input->mutex */
287 if (!ts
->disabled
&& !ts
->suspended
)
293 static void ad7879_close(struct input_dev
* input
)
295 struct ad7879
*ts
= input_get_drvdata(input
);
297 /* protected by input->mutex */
298 if (!ts
->disabled
&& !ts
->suspended
)
299 __ad7879_disable(ts
);
302 static int __maybe_unused
ad7879_suspend(struct device
*dev
)
304 struct ad7879
*ts
= dev_get_drvdata(dev
);
306 mutex_lock(&ts
->input
->mutex
);
308 if (!ts
->suspended
&& !ts
->disabled
&& ts
->input
->users
)
309 __ad7879_disable(ts
);
311 ts
->suspended
= true;
313 mutex_unlock(&ts
->input
->mutex
);
318 static int __maybe_unused
ad7879_resume(struct device
*dev
)
320 struct ad7879
*ts
= dev_get_drvdata(dev
);
322 mutex_lock(&ts
->input
->mutex
);
324 if (ts
->suspended
&& !ts
->disabled
&& ts
->input
->users
)
327 ts
->suspended
= false;
329 mutex_unlock(&ts
->input
->mutex
);
334 SIMPLE_DEV_PM_OPS(ad7879_pm_ops
, ad7879_suspend
, ad7879_resume
);
335 EXPORT_SYMBOL(ad7879_pm_ops
);
337 static void ad7879_toggle(struct ad7879
*ts
, bool disable
)
339 mutex_lock(&ts
->input
->mutex
);
341 if (!ts
->suspended
&& ts
->input
->users
!= 0) {
348 __ad7879_disable(ts
);
352 ts
->disabled
= disable
;
354 mutex_unlock(&ts
->input
->mutex
);
357 static ssize_t
ad7879_disable_show(struct device
*dev
,
358 struct device_attribute
*attr
, char *buf
)
360 struct ad7879
*ts
= dev_get_drvdata(dev
);
362 return sprintf(buf
, "%u\n", ts
->disabled
);
365 static ssize_t
ad7879_disable_store(struct device
*dev
,
366 struct device_attribute
*attr
,
367 const char *buf
, size_t count
)
369 struct ad7879
*ts
= dev_get_drvdata(dev
);
373 error
= kstrtouint(buf
, 10, &val
);
377 ad7879_toggle(ts
, val
);
382 static DEVICE_ATTR(disable
, 0664, ad7879_disable_show
, ad7879_disable_store
);
384 static struct attribute
*ad7879_attributes
[] = {
385 &dev_attr_disable
.attr
,
389 static const struct attribute_group ad7879_attr_group
= {
390 .attrs
= ad7879_attributes
,
393 #ifdef CONFIG_GPIOLIB
394 static int ad7879_gpio_direction_input(struct gpio_chip
*chip
,
397 struct ad7879
*ts
= gpiochip_get_data(chip
);
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
);
408 static int ad7879_gpio_direction_output(struct gpio_chip
*chip
,
409 unsigned gpio
, int level
)
411 struct ad7879
*ts
= gpiochip_get_data(chip
);
414 mutex_lock(&ts
->mutex
);
415 ts
->cmd_crtl2
&= ~AD7879_GPIODIR
;
416 ts
->cmd_crtl2
|= AD7879_GPIO_EN
| AD7879_GPIOPOL
;
418 ts
->cmd_crtl2
|= AD7879_GPIO_DATA
;
420 ts
->cmd_crtl2
&= ~AD7879_GPIO_DATA
;
422 err
= ad7879_write(ts
, AD7879_REG_CTRL2
, ts
->cmd_crtl2
);
423 mutex_unlock(&ts
->mutex
);
428 static int ad7879_gpio_get_value(struct gpio_chip
*chip
, unsigned gpio
)
430 struct ad7879
*ts
= gpiochip_get_data(chip
);
433 mutex_lock(&ts
->mutex
);
434 val
= ad7879_read(ts
, AD7879_REG_CTRL2
);
435 mutex_unlock(&ts
->mutex
);
437 return !!(val
& AD7879_GPIO_DATA
);
440 static void ad7879_gpio_set_value(struct gpio_chip
*chip
,
441 unsigned gpio
, int value
)
443 struct ad7879
*ts
= gpiochip_get_data(chip
);
445 mutex_lock(&ts
->mutex
);
447 ts
->cmd_crtl2
|= AD7879_GPIO_DATA
;
449 ts
->cmd_crtl2
&= ~AD7879_GPIO_DATA
;
451 ad7879_write(ts
, AD7879_REG_CTRL2
, ts
->cmd_crtl2
);
452 mutex_unlock(&ts
->mutex
);
455 static int ad7879_gpio_add(struct ad7879
*ts
,
456 const struct ad7879_platform_data
*pdata
)
463 gpio_export
= pdata
->gpio_export
;
464 gpio_base
= pdata
->gpio_base
;
466 gpio_export
= device_property_read_bool(ts
->dev
,
471 mutex_init(&ts
->mutex
);
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
;
481 ts
->gc
.label
= "AD7879-GPIO";
482 ts
->gc
.owner
= THIS_MODULE
;
483 ts
->gc
.parent
= ts
->dev
;
485 ret
= devm_gpiochip_add_data(ts
->dev
, &ts
->gc
, ts
);
487 dev_err(ts
->dev
, "failed to register gpio %d\n",
494 static int ad7879_gpio_add(struct ad7879
*ts
,
495 const struct ad7879_platform_data
*pdata
)
501 static int ad7879_parse_dt(struct device
*dev
, struct ad7879
*ts
)
506 err
= device_property_read_u32(dev
, "adi,resistance-plate-x", &tmp
);
508 dev_err(dev
, "failed to get resistance-plate-x property\n");
511 ts
->x_plate_ohms
= (u16
)tmp
;
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
);
522 ts
->swap_xy
= device_property_read_bool(dev
, "touchscreen-swapped-x-y");
527 static void ad7879_cleanup_sysfs(void *_ts
)
529 struct ad7879
*ts
= _ts
;
531 sysfs_remove_group(&ts
->dev
->kobj
, &ad7879_attr_group
);
534 int ad7879_probe(struct device
*dev
, struct regmap
*regmap
,
535 int irq
, u16 bustype
, u8 devid
)
537 struct ad7879_platform_data
*pdata
= dev_get_platdata(dev
);
539 struct input_dev
*input_dev
;
544 dev_err(dev
, "No IRQ specified\n");
548 ts
= devm_kzalloc(dev
, sizeof(*ts
), GFP_KERNEL
);
553 /* Platform data use swapped axis (backward compatibility) */
554 ts
->swap_xy
= !pdata
->swap_xy
;
556 ts
->x_plate_ohms
= pdata
->x_plate_ohms
? : 400;
558 ts
->first_conversion_delay
= pdata
->first_conversion_delay
;
559 ts
->acquisition_time
= pdata
->acquisition_time
;
560 ts
->averaging
= pdata
->averaging
;
561 ts
->pen_down_acc_interval
= pdata
->pen_down_acc_interval
;
562 ts
->median
= pdata
->median
;
564 err
= ad7879_parse_dt(dev
, ts
);
569 input_dev
= devm_input_allocate_device(dev
);
571 dev_err(dev
, "Failed to allocate input device\n");
576 ts
->input
= input_dev
;
580 setup_timer(&ts
->timer
, ad7879_timer
, (unsigned long) ts
);
581 snprintf(ts
->phys
, sizeof(ts
->phys
), "%s/input0", dev_name(dev
));
583 input_dev
->name
= "AD7879 Touchscreen";
584 input_dev
->phys
= ts
->phys
;
585 input_dev
->dev
.parent
= dev
;
586 input_dev
->id
.bustype
= bustype
;
588 input_dev
->open
= ad7879_open
;
589 input_dev
->close
= ad7879_close
;
591 input_set_drvdata(input_dev
, ts
);
593 input_set_capability(input_dev
, EV_KEY
, BTN_TOUCH
);
596 input_set_abs_params(input_dev
, ABS_X
,
598 pdata
->x_max
? : MAX_12BIT
,
600 input_set_abs_params(input_dev
, ABS_Y
,
602 pdata
->y_max
? : MAX_12BIT
,
604 input_set_abs_params(input_dev
, ABS_PRESSURE
,
606 pdata
->pressure_max
? : ~0,
609 input_set_abs_params(input_dev
, ABS_X
, 0, MAX_12BIT
, 0, 0);
610 input_set_abs_params(input_dev
, ABS_Y
, 0, MAX_12BIT
, 0, 0);
611 input_set_capability(input_dev
, EV_ABS
, ABS_PRESSURE
);
612 touchscreen_parse_properties(input_dev
, false, NULL
);
613 if (!input_abs_get_max(input_dev
, ABS_PRESSURE
)) {
614 dev_err(dev
, "Touchscreen pressure is not specified\n");
619 err
= ad7879_write(ts
, AD7879_REG_CTRL2
, AD7879_RESET
);
621 dev_err(dev
, "Failed to write %s\n", input_dev
->name
);
625 revid
= ad7879_read(ts
, AD7879_REG_REVID
);
626 input_dev
->id
.product
= (revid
& 0xff);
627 input_dev
->id
.version
= revid
>> 8;
628 if (input_dev
->id
.product
!= devid
) {
629 dev_err(dev
, "Failed to probe %s (%x vs %x)\n",
630 input_dev
->name
, devid
, revid
);
634 ts
->cmd_crtl3
= AD7879_YPLUS_BIT
|
638 AD7879_TEMPMASK_BIT
|
639 AD7879_AUXVBATMASK_BIT
|
640 AD7879_GPIOALERTMASK_BIT
;
642 ts
->cmd_crtl2
= AD7879_PM(AD7879_PM_DYN
) | AD7879_DFR
|
643 AD7879_AVG(ts
->averaging
) |
644 AD7879_MFS(ts
->median
) |
645 AD7879_FCD(ts
->first_conversion_delay
);
647 ts
->cmd_crtl1
= AD7879_MODE_INT
| AD7879_MODE_SEQ1
|
648 AD7879_ACQ(ts
->acquisition_time
) |
649 AD7879_TMR(ts
->pen_down_acc_interval
);
651 err
= devm_request_threaded_irq(dev
, ts
->irq
, NULL
, ad7879_irq
,
652 IRQF_TRIGGER_FALLING
| IRQF_ONESHOT
,
655 dev_err(dev
, "Failed to request IRQ: %d\n", err
);
659 __ad7879_disable(ts
);
661 err
= sysfs_create_group(&dev
->kobj
, &ad7879_attr_group
);
665 err
= devm_add_action_or_reset(dev
, ad7879_cleanup_sysfs
, ts
);
669 err
= ad7879_gpio_add(ts
, pdata
);
673 err
= input_register_device(input_dev
);
677 dev_set_drvdata(dev
, ts
);
681 EXPORT_SYMBOL(ad7879_probe
);
683 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
684 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
685 MODULE_LICENSE("GPL");