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");