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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/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 "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 u16 conversion_data[AD7879_NR_SENSE];
121 char phys[32];
122 u8 first_conversion_delay;
123 u8 acquisition_time;
124 u8 averaging;
125 u8 pen_down_acc_interval;
126 u8 median;
127 u16 x_plate_ohms;
128 u16 pressure_max;
129 u16 cmd_crtl1;
130 u16 cmd_crtl2;
131 u16 cmd_crtl3;
132 int x;
133 int y;
134 int Rt;
135};
136
137static int ad7879_read(struct ad7879 *ts, u8 reg)
138{
139 return ts->bops->read(ts->dev, reg);
140}
141
142static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
143{
144 return ts->bops->multi_read(ts->dev, first_reg, count, buf);
145}
146
147static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
148{
149 return ts->bops->write(ts->dev, reg, val);
150}
151
152static int ad7879_report(struct ad7879 *ts)
153{
154 struct input_dev *input_dev = ts->input;
155 unsigned Rt;
156 u16 x, y, z1, z2;
157
158 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
159 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
160 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
161 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
162
163 /*
164 * The samples processed here are already preprocessed by the AD7879.
165 * The preprocessing function consists of a median and an averaging
166 * filter. The combination of these two techniques provides a robust
167 * solution, discarding the spurious noise in the signal and keeping
168 * only the data of interest. The size of both filters is
169 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other
170 * user-programmable conversion controls include variable acquisition
171 * time, and first conversion delay. Up to 16 averages can be taken
172 * per conversion.
173 */
174
175 if (likely(x && z1)) {
176 /* compute touch pressure resistance using equation #1 */
177 Rt = (z2 - z1) * x * ts->x_plate_ohms;
178 Rt /= z1;
179 Rt = (Rt + 2047) >> 12;
180
181 /*
182 * Sample found inconsistent, pressure is beyond
183 * the maximum. Don't report it to user space.
184 */
185 if (Rt > ts->pressure_max)
186 return -EINVAL;
187
188 /*
189 * Note that we delay reporting events by one sample.
190 * This is done to avoid reporting last sample of the
191 * touch sequence, which may be incomplete if finger
192 * leaves the surface before last reading is taken.
193 */
194 if (timer_pending(&ts->timer)) {
195 /* Touch continues */
196 input_report_key(input_dev, BTN_TOUCH, 1);
197 input_report_abs(input_dev, ABS_X, ts->x);
198 input_report_abs(input_dev, ABS_Y, ts->y);
199 input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
200 input_sync(input_dev);
201 }
202
203 ts->x = x;
204 ts->y = y;
205 ts->Rt = Rt;
206
207 return 0;
208 }
209
210 return -EINVAL;
211}
212
213static void ad7879_ts_event_release(struct ad7879 *ts)
214{
215 struct input_dev *input_dev = ts->input;
216
217 input_report_abs(input_dev, ABS_PRESSURE, 0);
218 input_report_key(input_dev, BTN_TOUCH, 0);
219 input_sync(input_dev);
220}
221
222static void ad7879_timer(unsigned long handle)
223{
224 struct ad7879 *ts = (void *)handle;
225
226 ad7879_ts_event_release(ts);
227}
228
229static irqreturn_t ad7879_irq(int irq, void *handle)
230{
231 struct ad7879 *ts = handle;
232
233 ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
234
235 if (!ad7879_report(ts))
236 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
237
238 return IRQ_HANDLED;
239}
240
241static void __ad7879_enable(struct ad7879 *ts)
242{
243 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
244 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
245 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
246
247 enable_irq(ts->irq);
248}
249
250static void __ad7879_disable(struct ad7879 *ts)
251{
252 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
253 AD7879_PM(AD7879_PM_SHUTDOWN);
254 disable_irq(ts->irq);
255
256 if (del_timer_sync(&ts->timer))
257 ad7879_ts_event_release(ts);
258
259 ad7879_write(ts, AD7879_REG_CTRL2, reg);
260}
261
262
263static int ad7879_open(struct input_dev *input)
264{
265 struct ad7879 *ts = input_get_drvdata(input);
266
267 /* protected by input->mutex */
268 if (!ts->disabled && !ts->suspended)
269 __ad7879_enable(ts);
270
271 return 0;
272}
273
274static void ad7879_close(struct input_dev* input)
275{
276 struct ad7879 *ts = input_get_drvdata(input);
277
278 /* protected by input->mutex */
279 if (!ts->disabled && !ts->suspended)
280 __ad7879_disable(ts);
281}
282
283void ad7879_suspend(struct ad7879 *ts)
284{
285 mutex_lock(&ts->input->mutex);
286
287 if (!ts->suspended && !ts->disabled && ts->input->users)
288 __ad7879_disable(ts);
289
290 ts->suspended = true;
291
292 mutex_unlock(&ts->input->mutex);
293}
294EXPORT_SYMBOL(ad7879_suspend);
295
296void ad7879_resume(struct ad7879 *ts)
297{
298 mutex_lock(&ts->input->mutex);
299
300 if (ts->suspended && !ts->disabled && ts->input->users)
301 __ad7879_enable(ts);
302
303 ts->suspended = false;
304
305 mutex_unlock(&ts->input->mutex);
306}
307EXPORT_SYMBOL(ad7879_resume);
308
309static void ad7879_toggle(struct ad7879 *ts, bool disable)
310{
311 mutex_lock(&ts->input->mutex);
312
313 if (!ts->suspended && ts->input->users != 0) {
314
315 if (disable) {
316 if (ts->disabled)
317 __ad7879_enable(ts);
318 } else {
319 if (!ts->disabled)
320 __ad7879_disable(ts);
321 }
322 }
323
324 ts->disabled = disable;
325
326 mutex_unlock(&ts->input->mutex);
327}
328
329static ssize_t ad7879_disable_show(struct device *dev,
330 struct device_attribute *attr, char *buf)
331{
332 struct ad7879 *ts = dev_get_drvdata(dev);
333
334 return sprintf(buf, "%u\n", ts->disabled);
335}
336
337static ssize_t ad7879_disable_store(struct device *dev,
338 struct device_attribute *attr,
339 const char *buf, size_t count)
340{
341 struct ad7879 *ts = dev_get_drvdata(dev);
342 unsigned long val;
343 int error;
344
345 error = strict_strtoul(buf, 10, &val);
346 if (error)
347 return error;
348
349 ad7879_toggle(ts, val);
350
351 return count;
352}
353
354static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
355
356static struct attribute *ad7879_attributes[] = {
357 &dev_attr_disable.attr,
358 NULL
359};
360
361static const struct attribute_group ad7879_attr_group = {
362 .attrs = ad7879_attributes,
363};
364
365#ifdef CONFIG_GPIOLIB
366static int ad7879_gpio_direction_input(struct gpio_chip *chip,
367 unsigned gpio)
368{
369 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
370 int err;
371
372 mutex_lock(&ts->mutex);
373 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
374 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
375 mutex_unlock(&ts->mutex);
376
377 return err;
378}
379
380static int ad7879_gpio_direction_output(struct gpio_chip *chip,
381 unsigned gpio, int level)
382{
383 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
384 int err;
385
386 mutex_lock(&ts->mutex);
387 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
388 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
389 if (level)
390 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
391 else
392 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
393
394 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
395 mutex_unlock(&ts->mutex);
396
397 return err;
398}
399
400static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
401{
402 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
403 u16 val;
404
405 mutex_lock(&ts->mutex);
406 val = ad7879_read(ts, AD7879_REG_CTRL2);
407 mutex_unlock(&ts->mutex);
408
409 return !!(val & AD7879_GPIO_DATA);
410}
411
412static void ad7879_gpio_set_value(struct gpio_chip *chip,
413 unsigned gpio, int value)
414{
415 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
416
417 mutex_lock(&ts->mutex);
418 if (value)
419 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
420 else
421 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
422
423 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
424 mutex_unlock(&ts->mutex);
425}
426
427static int ad7879_gpio_add(struct ad7879 *ts,
428 const struct ad7879_platform_data *pdata)
429{
430 int ret = 0;
431
432 mutex_init(&ts->mutex);
433
434 if (pdata->gpio_export) {
435 ts->gc.direction_input = ad7879_gpio_direction_input;
436 ts->gc.direction_output = ad7879_gpio_direction_output;
437 ts->gc.get = ad7879_gpio_get_value;
438 ts->gc.set = ad7879_gpio_set_value;
439 ts->gc.can_sleep = 1;
440 ts->gc.base = pdata->gpio_base;
441 ts->gc.ngpio = 1;
442 ts->gc.label = "AD7879-GPIO";
443 ts->gc.owner = THIS_MODULE;
444 ts->gc.dev = ts->dev;
445
446 ret = gpiochip_add(&ts->gc);
447 if (ret)
448 dev_err(ts->dev, "failed to register gpio %d\n",
449 ts->gc.base);
450 }
451
452 return ret;
453}
454
455static void ad7879_gpio_remove(struct ad7879 *ts)
456{
457 const struct ad7879_platform_data *pdata = ts->dev->platform_data;
458 int ret;
459
460 if (pdata->gpio_export) {
461 ret = gpiochip_remove(&ts->gc);
462 if (ret)
463 dev_err(ts->dev, "failed to remove gpio %d\n",
464 ts->gc.base);
465 }
466}
467#else
468static inline int ad7879_gpio_add(struct ad7879 *ts,
469 const struct ad7879_platform_data *pdata)
470{
471 return 0;
472}
473
474static inline void ad7879_gpio_remove(struct ad7879 *ts)
475{
476}
477#endif
478
479struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
480 const struct ad7879_bus_ops *bops)
481{
482 struct ad7879_platform_data *pdata = dev->platform_data;
483 struct ad7879 *ts;
484 struct input_dev *input_dev;
485 int err;
486 u16 revid;
487
488 if (!irq) {
489 dev_err(dev, "no IRQ?\n");
490 err = -EINVAL;
491 goto err_out;
492 }
493
494 if (!pdata) {
495 dev_err(dev, "no platform data?\n");
496 err = -EINVAL;
497 goto err_out;
498 }
499
500 ts = kzalloc(sizeof(*ts), GFP_KERNEL);
501 input_dev = input_allocate_device();
502 if (!ts || !input_dev) {
503 err = -ENOMEM;
504 goto err_free_mem;
505 }
506
507 ts->bops = bops;
508 ts->dev = dev;
509 ts->input = input_dev;
510 ts->irq = irq;
511
512 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
513
514 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
515 ts->pressure_max = pdata->pressure_max ? : ~0;
516
517 ts->first_conversion_delay = pdata->first_conversion_delay;
518 ts->acquisition_time = pdata->acquisition_time;
519 ts->averaging = pdata->averaging;
520 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
521 ts->median = pdata->median;
522
523 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
524
525 input_dev->name = "AD7879 Touchscreen";
526 input_dev->phys = ts->phys;
527 input_dev->dev.parent = dev;
528 input_dev->id.bustype = bops->bustype;
529
530 input_dev->open = ad7879_open;
531 input_dev->close = ad7879_close;
532
533 input_set_drvdata(input_dev, ts);
534
535 __set_bit(EV_ABS, input_dev->evbit);
536 __set_bit(ABS_X, input_dev->absbit);
537 __set_bit(ABS_Y, input_dev->absbit);
538 __set_bit(ABS_PRESSURE, input_dev->absbit);
539
540 __set_bit(EV_KEY, input_dev->evbit);
541 __set_bit(BTN_TOUCH, input_dev->keybit);
542
543 input_set_abs_params(input_dev, ABS_X,
544 pdata->x_min ? : 0,
545 pdata->x_max ? : MAX_12BIT,
546 0, 0);
547 input_set_abs_params(input_dev, ABS_Y,
548 pdata->y_min ? : 0,
549 pdata->y_max ? : MAX_12BIT,
550 0, 0);
551 input_set_abs_params(input_dev, ABS_PRESSURE,
552 pdata->pressure_min, pdata->pressure_max, 0, 0);
553
554 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
555 if (err < 0) {
556 dev_err(dev, "Failed to write %s\n", input_dev->name);
557 goto err_free_mem;
558 }
559
560 revid = ad7879_read(ts, AD7879_REG_REVID);
561 input_dev->id.product = (revid & 0xff);
562 input_dev->id.version = revid >> 8;
563 if (input_dev->id.product != devid) {
564 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
565 input_dev->name, devid, revid);
566 err = -ENODEV;
567 goto err_free_mem;
568 }
569
570 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
571 AD7879_XPLUS_BIT |
572 AD7879_Z2_BIT |
573 AD7879_Z1_BIT |
574 AD7879_TEMPMASK_BIT |
575 AD7879_AUXVBATMASK_BIT |
576 AD7879_GPIOALERTMASK_BIT;
577
578 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
579 AD7879_AVG(ts->averaging) |
580 AD7879_MFS(ts->median) |
581 AD7879_FCD(ts->first_conversion_delay);
582
583 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
584 AD7879_ACQ(ts->acquisition_time) |
585 AD7879_TMR(ts->pen_down_acc_interval);
586
587 err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
588 IRQF_TRIGGER_FALLING,
589 dev_name(dev), ts);
590 if (err) {
591 dev_err(dev, "irq %d busy?\n", ts->irq);
592 goto err_free_mem;
593 }
594
595 __ad7879_disable(ts);
596
597 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
598 if (err)
599 goto err_free_irq;
600
601 err = ad7879_gpio_add(ts, pdata);
602 if (err)
603 goto err_remove_attr;
604
605 err = input_register_device(input_dev);
606 if (err)
607 goto err_remove_gpio;
608
609 return ts;
610
611err_remove_gpio:
612 ad7879_gpio_remove(ts);
613err_remove_attr:
614 sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
615err_free_irq:
616 free_irq(ts->irq, ts);
617err_free_mem:
618 input_free_device(input_dev);
619 kfree(ts);
620err_out:
621 return ERR_PTR(err);
622}
623EXPORT_SYMBOL(ad7879_probe);
624
625void ad7879_remove(struct ad7879 *ts)
626{
627 ad7879_gpio_remove(ts);
628 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
629 free_irq(ts->irq, ts);
630 input_unregister_device(ts->input);
631 kfree(ts);
632}
633EXPORT_SYMBOL(ad7879_remove);
634
635MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
636MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
637MODULE_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");