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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/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>
33
34#include <linux/spi/ad7879.h>
35#include <linux/module.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 bool swap_xy;
121 u16 conversion_data[AD7879_NR_SENSE];
122 char phys[32];
123 u8 first_conversion_delay;
124 u8 acquisition_time;
125 u8 averaging;
126 u8 pen_down_acc_interval;
127 u8 median;
128 u16 x_plate_ohms;
129 u16 pressure_max;
130 u16 cmd_crtl1;
131 u16 cmd_crtl2;
132 u16 cmd_crtl3;
133 int x;
134 int y;
135 int Rt;
136};
137
138static int ad7879_read(struct ad7879 *ts, u8 reg)
139{
140 return ts->bops->read(ts->dev, reg);
141}
142
143static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
144{
145 return ts->bops->multi_read(ts->dev, first_reg, count, buf);
146}
147
148static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
149{
150 return ts->bops->write(ts->dev, reg, val);
151}
152
153static int ad7879_report(struct ad7879 *ts)
154{
155 struct input_dev *input_dev = ts->input;
156 unsigned Rt;
157 u16 x, y, z1, z2;
158
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;
163
164 if (ts->swap_xy)
165 swap(x, y);
166
167 /*
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/spi/ad7879.h) Other
174 * user-programmable conversion controls include variable acquisition
175 * time, and first conversion delay. Up to 16 averages can be taken
176 * per conversion.
177 */
178
179 if (likely(x && z1)) {
180 /* compute touch pressure resistance using equation #1 */
181 Rt = (z2 - z1) * x * ts->x_plate_ohms;
182 Rt /= z1;
183 Rt = (Rt + 2047) >> 12;
184
185 /*
186 * Sample found inconsistent, pressure is beyond
187 * the maximum. Don't report it to user space.
188 */
189 if (Rt > ts->pressure_max)
190 return -EINVAL;
191
192 /*
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.
197 */
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);
205 }
206
207 ts->x = x;
208 ts->y = y;
209 ts->Rt = Rt;
210
211 return 0;
212 }
213
214 return -EINVAL;
215}
216
217static void ad7879_ts_event_release(struct ad7879 *ts)
218{
219 struct input_dev *input_dev = ts->input;
220
221 input_report_abs(input_dev, ABS_PRESSURE, 0);
222 input_report_key(input_dev, BTN_TOUCH, 0);
223 input_sync(input_dev);
224}
225
226static void ad7879_timer(unsigned long handle)
227{
228 struct ad7879 *ts = (void *)handle;
229
230 ad7879_ts_event_release(ts);
231}
232
233static irqreturn_t ad7879_irq(int irq, void *handle)
234{
235 struct ad7879 *ts = handle;
236
237 ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
238
239 if (!ad7879_report(ts))
240 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
241
242 return IRQ_HANDLED;
243}
244
245static void __ad7879_enable(struct ad7879 *ts)
246{
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);
250
251 enable_irq(ts->irq);
252}
253
254static void __ad7879_disable(struct ad7879 *ts)
255{
256 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
257 AD7879_PM(AD7879_PM_SHUTDOWN);
258 disable_irq(ts->irq);
259
260 if (del_timer_sync(&ts->timer))
261 ad7879_ts_event_release(ts);
262
263 ad7879_write(ts, AD7879_REG_CTRL2, reg);
264}
265
266
267static int ad7879_open(struct input_dev *input)
268{
269 struct ad7879 *ts = input_get_drvdata(input);
270
271 /* protected by input->mutex */
272 if (!ts->disabled && !ts->suspended)
273 __ad7879_enable(ts);
274
275 return 0;
276}
277
278static void ad7879_close(struct input_dev* input)
279{
280 struct ad7879 *ts = input_get_drvdata(input);
281
282 /* protected by input->mutex */
283 if (!ts->disabled && !ts->suspended)
284 __ad7879_disable(ts);
285}
286
287#ifdef CONFIG_PM_SLEEP
288static int ad7879_suspend(struct device *dev)
289{
290 struct ad7879 *ts = dev_get_drvdata(dev);
291
292 mutex_lock(&ts->input->mutex);
293
294 if (!ts->suspended && !ts->disabled && ts->input->users)
295 __ad7879_disable(ts);
296
297 ts->suspended = true;
298
299 mutex_unlock(&ts->input->mutex);
300
301 return 0;
302}
303
304static int ad7879_resume(struct device *dev)
305{
306 struct ad7879 *ts = dev_get_drvdata(dev);
307
308 mutex_lock(&ts->input->mutex);
309
310 if (ts->suspended && !ts->disabled && ts->input->users)
311 __ad7879_enable(ts);
312
313 ts->suspended = false;
314
315 mutex_unlock(&ts->input->mutex);
316
317 return 0;
318}
319#endif
320
321SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
322EXPORT_SYMBOL(ad7879_pm_ops);
323
324static void ad7879_toggle(struct ad7879 *ts, bool disable)
325{
326 mutex_lock(&ts->input->mutex);
327
328 if (!ts->suspended && ts->input->users != 0) {
329
330 if (disable) {
331 if (ts->disabled)
332 __ad7879_enable(ts);
333 } else {
334 if (!ts->disabled)
335 __ad7879_disable(ts);
336 }
337 }
338
339 ts->disabled = disable;
340
341 mutex_unlock(&ts->input->mutex);
342}
343
344static ssize_t ad7879_disable_show(struct device *dev,
345 struct device_attribute *attr, char *buf)
346{
347 struct ad7879 *ts = dev_get_drvdata(dev);
348
349 return sprintf(buf, "%u\n", ts->disabled);
350}
351
352static ssize_t ad7879_disable_store(struct device *dev,
353 struct device_attribute *attr,
354 const char *buf, size_t count)
355{
356 struct ad7879 *ts = dev_get_drvdata(dev);
357 unsigned int val;
358 int error;
359
360 error = kstrtouint(buf, 10, &val);
361 if (error)
362 return error;
363
364 ad7879_toggle(ts, val);
365
366 return count;
367}
368
369static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
370
371static struct attribute *ad7879_attributes[] = {
372 &dev_attr_disable.attr,
373 NULL
374};
375
376static const struct attribute_group ad7879_attr_group = {
377 .attrs = ad7879_attributes,
378};
379
380#ifdef CONFIG_GPIOLIB
381static int ad7879_gpio_direction_input(struct gpio_chip *chip,
382 unsigned gpio)
383{
384 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
385 int err;
386
387 mutex_lock(&ts->mutex);
388 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
389 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
390 mutex_unlock(&ts->mutex);
391
392 return err;
393}
394
395static int ad7879_gpio_direction_output(struct gpio_chip *chip,
396 unsigned gpio, int level)
397{
398 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
399 int err;
400
401 mutex_lock(&ts->mutex);
402 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
403 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
404 if (level)
405 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
406 else
407 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
408
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_get_value(struct gpio_chip *chip, unsigned gpio)
416{
417 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
418 u16 val;
419
420 mutex_lock(&ts->mutex);
421 val = ad7879_read(ts, AD7879_REG_CTRL2);
422 mutex_unlock(&ts->mutex);
423
424 return !!(val & AD7879_GPIO_DATA);
425}
426
427static void ad7879_gpio_set_value(struct gpio_chip *chip,
428 unsigned gpio, int value)
429{
430 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
431
432 mutex_lock(&ts->mutex);
433 if (value)
434 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
435 else
436 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
437
438 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
439 mutex_unlock(&ts->mutex);
440}
441
442static int ad7879_gpio_add(struct ad7879 *ts,
443 const struct ad7879_platform_data *pdata)
444{
445 int ret = 0;
446
447 mutex_init(&ts->mutex);
448
449 if (pdata->gpio_export) {
450 ts->gc.direction_input = ad7879_gpio_direction_input;
451 ts->gc.direction_output = ad7879_gpio_direction_output;
452 ts->gc.get = ad7879_gpio_get_value;
453 ts->gc.set = ad7879_gpio_set_value;
454 ts->gc.can_sleep = 1;
455 ts->gc.base = pdata->gpio_base;
456 ts->gc.ngpio = 1;
457 ts->gc.label = "AD7879-GPIO";
458 ts->gc.owner = THIS_MODULE;
459 ts->gc.dev = ts->dev;
460
461 ret = gpiochip_add(&ts->gc);
462 if (ret)
463 dev_err(ts->dev, "failed to register gpio %d\n",
464 ts->gc.base);
465 }
466
467 return ret;
468}
469
470static void ad7879_gpio_remove(struct ad7879 *ts)
471{
472 const struct ad7879_platform_data *pdata = dev_get_platdata(ts->dev);
473 int ret;
474
475 if (pdata->gpio_export) {
476 ret = gpiochip_remove(&ts->gc);
477 if (ret)
478 dev_err(ts->dev, "failed to remove gpio %d\n",
479 ts->gc.base);
480 }
481}
482#else
483static inline int ad7879_gpio_add(struct ad7879 *ts,
484 const struct ad7879_platform_data *pdata)
485{
486 return 0;
487}
488
489static inline void ad7879_gpio_remove(struct ad7879 *ts)
490{
491}
492#endif
493
494struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
495 const struct ad7879_bus_ops *bops)
496{
497 struct ad7879_platform_data *pdata = dev_get_platdata(dev);
498 struct ad7879 *ts;
499 struct input_dev *input_dev;
500 int err;
501 u16 revid;
502
503 if (!irq) {
504 dev_err(dev, "no IRQ?\n");
505 err = -EINVAL;
506 goto err_out;
507 }
508
509 if (!pdata) {
510 dev_err(dev, "no platform data?\n");
511 err = -EINVAL;
512 goto err_out;
513 }
514
515 ts = kzalloc(sizeof(*ts), GFP_KERNEL);
516 input_dev = input_allocate_device();
517 if (!ts || !input_dev) {
518 err = -ENOMEM;
519 goto err_free_mem;
520 }
521
522 ts->bops = bops;
523 ts->dev = dev;
524 ts->input = input_dev;
525 ts->irq = irq;
526 ts->swap_xy = pdata->swap_xy;
527
528 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
529
530 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
531 ts->pressure_max = pdata->pressure_max ? : ~0;
532
533 ts->first_conversion_delay = pdata->first_conversion_delay;
534 ts->acquisition_time = pdata->acquisition_time;
535 ts->averaging = pdata->averaging;
536 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
537 ts->median = pdata->median;
538
539 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
540
541 input_dev->name = "AD7879 Touchscreen";
542 input_dev->phys = ts->phys;
543 input_dev->dev.parent = dev;
544 input_dev->id.bustype = bops->bustype;
545
546 input_dev->open = ad7879_open;
547 input_dev->close = ad7879_close;
548
549 input_set_drvdata(input_dev, ts);
550
551 __set_bit(EV_ABS, input_dev->evbit);
552 __set_bit(ABS_X, input_dev->absbit);
553 __set_bit(ABS_Y, input_dev->absbit);
554 __set_bit(ABS_PRESSURE, input_dev->absbit);
555
556 __set_bit(EV_KEY, input_dev->evbit);
557 __set_bit(BTN_TOUCH, input_dev->keybit);
558
559 input_set_abs_params(input_dev, ABS_X,
560 pdata->x_min ? : 0,
561 pdata->x_max ? : MAX_12BIT,
562 0, 0);
563 input_set_abs_params(input_dev, ABS_Y,
564 pdata->y_min ? : 0,
565 pdata->y_max ? : MAX_12BIT,
566 0, 0);
567 input_set_abs_params(input_dev, ABS_PRESSURE,
568 pdata->pressure_min, pdata->pressure_max, 0, 0);
569
570 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
571 if (err < 0) {
572 dev_err(dev, "Failed to write %s\n", input_dev->name);
573 goto err_free_mem;
574 }
575
576 revid = ad7879_read(ts, AD7879_REG_REVID);
577 input_dev->id.product = (revid & 0xff);
578 input_dev->id.version = revid >> 8;
579 if (input_dev->id.product != devid) {
580 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
581 input_dev->name, devid, revid);
582 err = -ENODEV;
583 goto err_free_mem;
584 }
585
586 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
587 AD7879_XPLUS_BIT |
588 AD7879_Z2_BIT |
589 AD7879_Z1_BIT |
590 AD7879_TEMPMASK_BIT |
591 AD7879_AUXVBATMASK_BIT |
592 AD7879_GPIOALERTMASK_BIT;
593
594 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
595 AD7879_AVG(ts->averaging) |
596 AD7879_MFS(ts->median) |
597 AD7879_FCD(ts->first_conversion_delay);
598
599 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
600 AD7879_ACQ(ts->acquisition_time) |
601 AD7879_TMR(ts->pen_down_acc_interval);
602
603 err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
604 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
605 dev_name(dev), ts);
606 if (err) {
607 dev_err(dev, "irq %d busy?\n", ts->irq);
608 goto err_free_mem;
609 }
610
611 __ad7879_disable(ts);
612
613 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
614 if (err)
615 goto err_free_irq;
616
617 err = ad7879_gpio_add(ts, pdata);
618 if (err)
619 goto err_remove_attr;
620
621 err = input_register_device(input_dev);
622 if (err)
623 goto err_remove_gpio;
624
625 return ts;
626
627err_remove_gpio:
628 ad7879_gpio_remove(ts);
629err_remove_attr:
630 sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
631err_free_irq:
632 free_irq(ts->irq, ts);
633err_free_mem:
634 input_free_device(input_dev);
635 kfree(ts);
636err_out:
637 return ERR_PTR(err);
638}
639EXPORT_SYMBOL(ad7879_probe);
640
641void ad7879_remove(struct ad7879 *ts)
642{
643 ad7879_gpio_remove(ts);
644 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
645 free_irq(ts->irq, ts);
646 input_unregister_device(ts->input);
647 kfree(ts);
648}
649EXPORT_SYMBOL(ad7879_remove);
650
651MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
652MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
653MODULE_LICENSE("GPL");
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 <linux/module.h>
37#include "ad7879.h"
38
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
54
55/* Control REG 1 */
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 */
63
64/* Control REG 2 */
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)
79
80/* Control REG 3 */
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)
96
97enum {
98 AD7879_SEQ_XPOS = 0,
99 AD7879_SEQ_YPOS = 1,
100 AD7879_SEQ_Z1 = 2,
101 AD7879_SEQ_Z2 = 3,
102 AD7879_NR_SENSE = 4,
103};
104
105#define MAX_12BIT ((1<<12)-1)
106#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)
107
108struct ad7879 {
109 const struct ad7879_bus_ops *bops;
110
111 struct device *dev;
112 struct input_dev *input;
113 struct timer_list timer;
114#ifdef CONFIG_GPIOLIB
115 struct gpio_chip gc;
116 struct mutex mutex;
117#endif
118 unsigned int irq;
119 bool disabled; /* P: input->mutex */
120 bool suspended; /* P: input->mutex */
121 u16 conversion_data[AD7879_NR_SENSE];
122 char phys[32];
123 u8 first_conversion_delay;
124 u8 acquisition_time;
125 u8 averaging;
126 u8 pen_down_acc_interval;
127 u8 median;
128 u16 x_plate_ohms;
129 u16 pressure_max;
130 u16 cmd_crtl1;
131 u16 cmd_crtl2;
132 u16 cmd_crtl3;
133 int x;
134 int y;
135 int Rt;
136};
137
138static int ad7879_read(struct ad7879 *ts, u8 reg)
139{
140 return ts->bops->read(ts->dev, reg);
141}
142
143static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
144{
145 return ts->bops->multi_read(ts->dev, first_reg, count, buf);
146}
147
148static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
149{
150 return ts->bops->write(ts->dev, reg, val);
151}
152
153static int ad7879_report(struct ad7879 *ts)
154{
155 struct input_dev *input_dev = ts->input;
156 unsigned Rt;
157 u16 x, y, z1, z2;
158
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;
163
164 /*
165 * The samples processed here are already preprocessed by the AD7879.
166 * The preprocessing function consists of a median and an averaging
167 * filter. The combination of these two techniques provides a robust
168 * solution, discarding the spurious noise in the signal and keeping
169 * only the data of interest. The size of both filters is
170 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other
171 * user-programmable conversion controls include variable acquisition
172 * time, and first conversion delay. Up to 16 averages can be taken
173 * per conversion.
174 */
175
176 if (likely(x && z1)) {
177 /* compute touch pressure resistance using equation #1 */
178 Rt = (z2 - z1) * x * ts->x_plate_ohms;
179 Rt /= z1;
180 Rt = (Rt + 2047) >> 12;
181
182 /*
183 * Sample found inconsistent, pressure is beyond
184 * the maximum. Don't report it to user space.
185 */
186 if (Rt > ts->pressure_max)
187 return -EINVAL;
188
189 /*
190 * Note that we delay reporting events by one sample.
191 * This is done to avoid reporting last sample of the
192 * touch sequence, which may be incomplete if finger
193 * leaves the surface before last reading is taken.
194 */
195 if (timer_pending(&ts->timer)) {
196 /* Touch continues */
197 input_report_key(input_dev, BTN_TOUCH, 1);
198 input_report_abs(input_dev, ABS_X, ts->x);
199 input_report_abs(input_dev, ABS_Y, ts->y);
200 input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
201 input_sync(input_dev);
202 }
203
204 ts->x = x;
205 ts->y = y;
206 ts->Rt = Rt;
207
208 return 0;
209 }
210
211 return -EINVAL;
212}
213
214static void ad7879_ts_event_release(struct ad7879 *ts)
215{
216 struct input_dev *input_dev = ts->input;
217
218 input_report_abs(input_dev, ABS_PRESSURE, 0);
219 input_report_key(input_dev, BTN_TOUCH, 0);
220 input_sync(input_dev);
221}
222
223static void ad7879_timer(unsigned long handle)
224{
225 struct ad7879 *ts = (void *)handle;
226
227 ad7879_ts_event_release(ts);
228}
229
230static irqreturn_t ad7879_irq(int irq, void *handle)
231{
232 struct ad7879 *ts = handle;
233
234 ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
235
236 if (!ad7879_report(ts))
237 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
238
239 return IRQ_HANDLED;
240}
241
242static void __ad7879_enable(struct ad7879 *ts)
243{
244 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
245 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
246 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
247
248 enable_irq(ts->irq);
249}
250
251static void __ad7879_disable(struct ad7879 *ts)
252{
253 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
254 AD7879_PM(AD7879_PM_SHUTDOWN);
255 disable_irq(ts->irq);
256
257 if (del_timer_sync(&ts->timer))
258 ad7879_ts_event_release(ts);
259
260 ad7879_write(ts, AD7879_REG_CTRL2, reg);
261}
262
263
264static int ad7879_open(struct input_dev *input)
265{
266 struct ad7879 *ts = input_get_drvdata(input);
267
268 /* protected by input->mutex */
269 if (!ts->disabled && !ts->suspended)
270 __ad7879_enable(ts);
271
272 return 0;
273}
274
275static void ad7879_close(struct input_dev* input)
276{
277 struct ad7879 *ts = input_get_drvdata(input);
278
279 /* protected by input->mutex */
280 if (!ts->disabled && !ts->suspended)
281 __ad7879_disable(ts);
282}
283
284#ifdef CONFIG_PM_SLEEP
285static int ad7879_suspend(struct device *dev)
286{
287 struct ad7879 *ts = dev_get_drvdata(dev);
288
289 mutex_lock(&ts->input->mutex);
290
291 if (!ts->suspended && !ts->disabled && ts->input->users)
292 __ad7879_disable(ts);
293
294 ts->suspended = true;
295
296 mutex_unlock(&ts->input->mutex);
297
298 return 0;
299}
300
301static int ad7879_resume(struct device *dev)
302{
303 struct ad7879 *ts = dev_get_drvdata(dev);
304
305 mutex_lock(&ts->input->mutex);
306
307 if (ts->suspended && !ts->disabled && ts->input->users)
308 __ad7879_enable(ts);
309
310 ts->suspended = false;
311
312 mutex_unlock(&ts->input->mutex);
313
314 return 0;
315}
316#endif
317
318SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
319EXPORT_SYMBOL(ad7879_pm_ops);
320
321static void ad7879_toggle(struct ad7879 *ts, bool disable)
322{
323 mutex_lock(&ts->input->mutex);
324
325 if (!ts->suspended && ts->input->users != 0) {
326
327 if (disable) {
328 if (ts->disabled)
329 __ad7879_enable(ts);
330 } else {
331 if (!ts->disabled)
332 __ad7879_disable(ts);
333 }
334 }
335
336 ts->disabled = disable;
337
338 mutex_unlock(&ts->input->mutex);
339}
340
341static ssize_t ad7879_disable_show(struct device *dev,
342 struct device_attribute *attr, char *buf)
343{
344 struct ad7879 *ts = dev_get_drvdata(dev);
345
346 return sprintf(buf, "%u\n", ts->disabled);
347}
348
349static ssize_t ad7879_disable_store(struct device *dev,
350 struct device_attribute *attr,
351 const char *buf, size_t count)
352{
353 struct ad7879 *ts = dev_get_drvdata(dev);
354 unsigned int val;
355 int error;
356
357 error = kstrtouint(buf, 10, &val);
358 if (error)
359 return error;
360
361 ad7879_toggle(ts, val);
362
363 return count;
364}
365
366static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
367
368static struct attribute *ad7879_attributes[] = {
369 &dev_attr_disable.attr,
370 NULL
371};
372
373static const struct attribute_group ad7879_attr_group = {
374 .attrs = ad7879_attributes,
375};
376
377#ifdef CONFIG_GPIOLIB
378static int ad7879_gpio_direction_input(struct gpio_chip *chip,
379 unsigned gpio)
380{
381 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
382 int err;
383
384 mutex_lock(&ts->mutex);
385 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
386 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
387 mutex_unlock(&ts->mutex);
388
389 return err;
390}
391
392static int ad7879_gpio_direction_output(struct gpio_chip *chip,
393 unsigned gpio, int level)
394{
395 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
396 int err;
397
398 mutex_lock(&ts->mutex);
399 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
400 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
401 if (level)
402 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
403 else
404 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
405
406 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
407 mutex_unlock(&ts->mutex);
408
409 return err;
410}
411
412static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
413{
414 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
415 u16 val;
416
417 mutex_lock(&ts->mutex);
418 val = ad7879_read(ts, AD7879_REG_CTRL2);
419 mutex_unlock(&ts->mutex);
420
421 return !!(val & AD7879_GPIO_DATA);
422}
423
424static void ad7879_gpio_set_value(struct gpio_chip *chip,
425 unsigned gpio, int value)
426{
427 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
428
429 mutex_lock(&ts->mutex);
430 if (value)
431 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
432 else
433 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
434
435 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
436 mutex_unlock(&ts->mutex);
437}
438
439static int ad7879_gpio_add(struct ad7879 *ts,
440 const struct ad7879_platform_data *pdata)
441{
442 int ret = 0;
443
444 mutex_init(&ts->mutex);
445
446 if (pdata->gpio_export) {
447 ts->gc.direction_input = ad7879_gpio_direction_input;
448 ts->gc.direction_output = ad7879_gpio_direction_output;
449 ts->gc.get = ad7879_gpio_get_value;
450 ts->gc.set = ad7879_gpio_set_value;
451 ts->gc.can_sleep = 1;
452 ts->gc.base = pdata->gpio_base;
453 ts->gc.ngpio = 1;
454 ts->gc.label = "AD7879-GPIO";
455 ts->gc.owner = THIS_MODULE;
456 ts->gc.dev = ts->dev;
457
458 ret = gpiochip_add(&ts->gc);
459 if (ret)
460 dev_err(ts->dev, "failed to register gpio %d\n",
461 ts->gc.base);
462 }
463
464 return ret;
465}
466
467static void ad7879_gpio_remove(struct ad7879 *ts)
468{
469 const struct ad7879_platform_data *pdata = ts->dev->platform_data;
470 int ret;
471
472 if (pdata->gpio_export) {
473 ret = gpiochip_remove(&ts->gc);
474 if (ret)
475 dev_err(ts->dev, "failed to remove gpio %d\n",
476 ts->gc.base);
477 }
478}
479#else
480static inline int ad7879_gpio_add(struct ad7879 *ts,
481 const struct ad7879_platform_data *pdata)
482{
483 return 0;
484}
485
486static inline void ad7879_gpio_remove(struct ad7879 *ts)
487{
488}
489#endif
490
491struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
492 const struct ad7879_bus_ops *bops)
493{
494 struct ad7879_platform_data *pdata = dev->platform_data;
495 struct ad7879 *ts;
496 struct input_dev *input_dev;
497 int err;
498 u16 revid;
499
500 if (!irq) {
501 dev_err(dev, "no IRQ?\n");
502 err = -EINVAL;
503 goto err_out;
504 }
505
506 if (!pdata) {
507 dev_err(dev, "no platform data?\n");
508 err = -EINVAL;
509 goto err_out;
510 }
511
512 ts = kzalloc(sizeof(*ts), GFP_KERNEL);
513 input_dev = input_allocate_device();
514 if (!ts || !input_dev) {
515 err = -ENOMEM;
516 goto err_free_mem;
517 }
518
519 ts->bops = bops;
520 ts->dev = dev;
521 ts->input = input_dev;
522 ts->irq = irq;
523
524 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
525
526 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
527 ts->pressure_max = pdata->pressure_max ? : ~0;
528
529 ts->first_conversion_delay = pdata->first_conversion_delay;
530 ts->acquisition_time = pdata->acquisition_time;
531 ts->averaging = pdata->averaging;
532 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
533 ts->median = pdata->median;
534
535 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
536
537 input_dev->name = "AD7879 Touchscreen";
538 input_dev->phys = ts->phys;
539 input_dev->dev.parent = dev;
540 input_dev->id.bustype = bops->bustype;
541
542 input_dev->open = ad7879_open;
543 input_dev->close = ad7879_close;
544
545 input_set_drvdata(input_dev, ts);
546
547 __set_bit(EV_ABS, input_dev->evbit);
548 __set_bit(ABS_X, input_dev->absbit);
549 __set_bit(ABS_Y, input_dev->absbit);
550 __set_bit(ABS_PRESSURE, input_dev->absbit);
551
552 __set_bit(EV_KEY, input_dev->evbit);
553 __set_bit(BTN_TOUCH, input_dev->keybit);
554
555 input_set_abs_params(input_dev, ABS_X,
556 pdata->x_min ? : 0,
557 pdata->x_max ? : MAX_12BIT,
558 0, 0);
559 input_set_abs_params(input_dev, ABS_Y,
560 pdata->y_min ? : 0,
561 pdata->y_max ? : MAX_12BIT,
562 0, 0);
563 input_set_abs_params(input_dev, ABS_PRESSURE,
564 pdata->pressure_min, pdata->pressure_max, 0, 0);
565
566 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
567 if (err < 0) {
568 dev_err(dev, "Failed to write %s\n", input_dev->name);
569 goto err_free_mem;
570 }
571
572 revid = ad7879_read(ts, AD7879_REG_REVID);
573 input_dev->id.product = (revid & 0xff);
574 input_dev->id.version = revid >> 8;
575 if (input_dev->id.product != devid) {
576 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
577 input_dev->name, devid, revid);
578 err = -ENODEV;
579 goto err_free_mem;
580 }
581
582 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
583 AD7879_XPLUS_BIT |
584 AD7879_Z2_BIT |
585 AD7879_Z1_BIT |
586 AD7879_TEMPMASK_BIT |
587 AD7879_AUXVBATMASK_BIT |
588 AD7879_GPIOALERTMASK_BIT;
589
590 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
591 AD7879_AVG(ts->averaging) |
592 AD7879_MFS(ts->median) |
593 AD7879_FCD(ts->first_conversion_delay);
594
595 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
596 AD7879_ACQ(ts->acquisition_time) |
597 AD7879_TMR(ts->pen_down_acc_interval);
598
599 err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
600 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
601 dev_name(dev), ts);
602 if (err) {
603 dev_err(dev, "irq %d busy?\n", ts->irq);
604 goto err_free_mem;
605 }
606
607 __ad7879_disable(ts);
608
609 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
610 if (err)
611 goto err_free_irq;
612
613 err = ad7879_gpio_add(ts, pdata);
614 if (err)
615 goto err_remove_attr;
616
617 err = input_register_device(input_dev);
618 if (err)
619 goto err_remove_gpio;
620
621 return ts;
622
623err_remove_gpio:
624 ad7879_gpio_remove(ts);
625err_remove_attr:
626 sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
627err_free_irq:
628 free_irq(ts->irq, ts);
629err_free_mem:
630 input_free_device(input_dev);
631 kfree(ts);
632err_out:
633 return ERR_PTR(err);
634}
635EXPORT_SYMBOL(ad7879_probe);
636
637void ad7879_remove(struct ad7879 *ts)
638{
639 ad7879_gpio_remove(ts);
640 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
641 free_irq(ts->irq, ts);
642 input_unregister_device(ts->input);
643 kfree(ts);
644}
645EXPORT_SYMBOL(ad7879_remove);
646
647MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
648MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
649MODULE_LICENSE("GPL");