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Merge remote-tracking branch 'moduleh/module.h-split'
[linux-2.6/next.git] / drivers / input / touchscreen / ad7879.c
blob3b2e9ed2aeec3482c7ec178b238410fc93424ff2
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
97 enum {
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
108 struct 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
138 static int ad7879_read(struct ad7879 *ts, u8 reg)
139 {
140 return ts->bops->read(ts->dev, reg);
141 }
142
143 static 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
148 static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
149 {
150 return ts->bops->write(ts->dev, reg, val);
151 }
152
153 static 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
214 static 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
223 static void ad7879_timer(unsigned long handle)
224 {
225 struct ad7879 *ts = (void *)handle;
226
227 ad7879_ts_event_release(ts);
228 }
229
230 static 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
242 static 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
251 static 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
264 static 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
275 static 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 void ad7879_suspend(struct ad7879 *ts)
285 {
286 mutex_lock(&ts->input->mutex);
287
288 if (!ts->suspended && !ts->disabled && ts->input->users)
289 __ad7879_disable(ts);
290
291 ts->suspended = true;
292
293 mutex_unlock(&ts->input->mutex);
294 }
295 EXPORT_SYMBOL(ad7879_suspend);
296
297 void ad7879_resume(struct ad7879 *ts)
298 {
299 mutex_lock(&ts->input->mutex);
300
301 if (ts->suspended && !ts->disabled && ts->input->users)
302 __ad7879_enable(ts);
303
304 ts->suspended = false;
305
306 mutex_unlock(&ts->input->mutex);
307 }
308 EXPORT_SYMBOL(ad7879_resume);
309
310 static void ad7879_toggle(struct ad7879 *ts, bool disable)
311 {
312 mutex_lock(&ts->input->mutex);
313
314 if (!ts->suspended && ts->input->users != 0) {
315
316 if (disable) {
317 if (ts->disabled)
318 __ad7879_enable(ts);
319 } else {
320 if (!ts->disabled)
321 __ad7879_disable(ts);
322 }
323 }
324
325 ts->disabled = disable;
326
327 mutex_unlock(&ts->input->mutex);
328 }
329
330 static ssize_t ad7879_disable_show(struct device *dev,
331 struct device_attribute *attr, char *buf)
332 {
333 struct ad7879 *ts = dev_get_drvdata(dev);
334
335 return sprintf(buf, "%u\n", ts->disabled);
336 }
337
338 static ssize_t ad7879_disable_store(struct device *dev,
339 struct device_attribute *attr,
340 const char *buf, size_t count)
341 {
342 struct ad7879 *ts = dev_get_drvdata(dev);
343 unsigned long val;
344 int error;
345
346 error = strict_strtoul(buf, 10, &val);
347 if (error)
348 return error;
349
350 ad7879_toggle(ts, val);
351
352 return count;
353 }
354
355 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
356
357 static struct attribute *ad7879_attributes[] = {
358 &dev_attr_disable.attr,
359 NULL
360 };
361
362 static const struct attribute_group ad7879_attr_group = {
363 .attrs = ad7879_attributes,
364 };
365
366 #ifdef CONFIG_GPIOLIB
367 static int ad7879_gpio_direction_input(struct gpio_chip *chip,
368 unsigned gpio)
369 {
370 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
371 int err;
372
373 mutex_lock(&ts->mutex);
374 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
375 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
376 mutex_unlock(&ts->mutex);
377
378 return err;
379 }
380
381 static int ad7879_gpio_direction_output(struct gpio_chip *chip,
382 unsigned gpio, int level)
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_GPIODIR;
389 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
390 if (level)
391 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
392 else
393 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
394
395 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
396 mutex_unlock(&ts->mutex);
397
398 return err;
399 }
400
401 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
402 {
403 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
404 u16 val;
405
406 mutex_lock(&ts->mutex);
407 val = ad7879_read(ts, AD7879_REG_CTRL2);
408 mutex_unlock(&ts->mutex);
409
410 return !!(val & AD7879_GPIO_DATA);
411 }
412
413 static void ad7879_gpio_set_value(struct gpio_chip *chip,
414 unsigned gpio, int value)
415 {
416 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
417
418 mutex_lock(&ts->mutex);
419 if (value)
420 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
421 else
422 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
423
424 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
425 mutex_unlock(&ts->mutex);
426 }
427
428 static int ad7879_gpio_add(struct ad7879 *ts,
429 const struct ad7879_platform_data *pdata)
430 {
431 int ret = 0;
432
433 mutex_init(&ts->mutex);
434
435 if (pdata->gpio_export) {
436 ts->gc.direction_input = ad7879_gpio_direction_input;
437 ts->gc.direction_output = ad7879_gpio_direction_output;
438 ts->gc.get = ad7879_gpio_get_value;
439 ts->gc.set = ad7879_gpio_set_value;
440 ts->gc.can_sleep = 1;
441 ts->gc.base = pdata->gpio_base;
442 ts->gc.ngpio = 1;
443 ts->gc.label = "AD7879-GPIO";
444 ts->gc.owner = THIS_MODULE;
445 ts->gc.dev = ts->dev;
446
447 ret = gpiochip_add(&ts->gc);
448 if (ret)
449 dev_err(ts->dev, "failed to register gpio %d\n",
450 ts->gc.base);
451 }
452
453 return ret;
454 }
455
456 static void ad7879_gpio_remove(struct ad7879 *ts)
457 {
458 const struct ad7879_platform_data *pdata = ts->dev->platform_data;
459 int ret;
460
461 if (pdata->gpio_export) {
462 ret = gpiochip_remove(&ts->gc);
463 if (ret)
464 dev_err(ts->dev, "failed to remove gpio %d\n",
465 ts->gc.base);
466 }
467 }
468 #else
469 static inline int ad7879_gpio_add(struct ad7879 *ts,
470 const struct ad7879_platform_data *pdata)
471 {
472 return 0;
473 }
474
475 static inline void ad7879_gpio_remove(struct ad7879 *ts)
476 {
477 }
478 #endif
479
480 struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
481 const struct ad7879_bus_ops *bops)
482 {
483 struct ad7879_platform_data *pdata = dev->platform_data;
484 struct ad7879 *ts;
485 struct input_dev *input_dev;
486 int err;
487 u16 revid;
488
489 if (!irq) {
490 dev_err(dev, "no IRQ?\n");
491 err = -EINVAL;
492 goto err_out;
493 }
494
495 if (!pdata) {
496 dev_err(dev, "no platform data?\n");
497 err = -EINVAL;
498 goto err_out;
499 }
500
501 ts = kzalloc(sizeof(*ts), GFP_KERNEL);
502 input_dev = input_allocate_device();
503 if (!ts || !input_dev) {
504 err = -ENOMEM;
505 goto err_free_mem;
506 }
507
508 ts->bops = bops;
509 ts->dev = dev;
510 ts->input = input_dev;
511 ts->irq = irq;
512
513 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
514
515 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
516 ts->pressure_max = pdata->pressure_max ? : ~0;
517
518 ts->first_conversion_delay = pdata->first_conversion_delay;
519 ts->acquisition_time = pdata->acquisition_time;
520 ts->averaging = pdata->averaging;
521 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
522 ts->median = pdata->median;
523
524 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
525
526 input_dev->name = "AD7879 Touchscreen";
527 input_dev->phys = ts->phys;
528 input_dev->dev.parent = dev;
529 input_dev->id.bustype = bops->bustype;
530
531 input_dev->open = ad7879_open;
532 input_dev->close = ad7879_close;
533
534 input_set_drvdata(input_dev, ts);
535
536 __set_bit(EV_ABS, input_dev->evbit);
537 __set_bit(ABS_X, input_dev->absbit);
538 __set_bit(ABS_Y, input_dev->absbit);
539 __set_bit(ABS_PRESSURE, input_dev->absbit);
540
541 __set_bit(EV_KEY, input_dev->evbit);
542 __set_bit(BTN_TOUCH, input_dev->keybit);
543
544 input_set_abs_params(input_dev, ABS_X,
545 pdata->x_min ? : 0,
546 pdata->x_max ? : MAX_12BIT,
547 0, 0);
548 input_set_abs_params(input_dev, ABS_Y,
549 pdata->y_min ? : 0,
550 pdata->y_max ? : MAX_12BIT,
551 0, 0);
552 input_set_abs_params(input_dev, ABS_PRESSURE,
553 pdata->pressure_min, pdata->pressure_max, 0, 0);
554
555 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
556 if (err < 0) {
557 dev_err(dev, "Failed to write %s\n", input_dev->name);
558 goto err_free_mem;
559 }
560
561 revid = ad7879_read(ts, AD7879_REG_REVID);
562 input_dev->id.product = (revid & 0xff);
563 input_dev->id.version = revid >> 8;
564 if (input_dev->id.product != devid) {
565 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
566 input_dev->name, devid, revid);
567 err = -ENODEV;
568 goto err_free_mem;
569 }
570
571 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
572 AD7879_XPLUS_BIT |
573 AD7879_Z2_BIT |
574 AD7879_Z1_BIT |
575 AD7879_TEMPMASK_BIT |
576 AD7879_AUXVBATMASK_BIT |
577 AD7879_GPIOALERTMASK_BIT;
578
579 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
580 AD7879_AVG(ts->averaging) |
581 AD7879_MFS(ts->median) |
582 AD7879_FCD(ts->first_conversion_delay);
583
584 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
585 AD7879_ACQ(ts->acquisition_time) |
586 AD7879_TMR(ts->pen_down_acc_interval);
587
588 err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
589 IRQF_TRIGGER_FALLING,
590 dev_name(dev), ts);
591 if (err) {
592 dev_err(dev, "irq %d busy?\n", ts->irq);
593 goto err_free_mem;
594 }
595
596 __ad7879_disable(ts);
597
598 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
599 if (err)
600 goto err_free_irq;
601
602 err = ad7879_gpio_add(ts, pdata);
603 if (err)
604 goto err_remove_attr;
605
606 err = input_register_device(input_dev);
607 if (err)
608 goto err_remove_gpio;
609
610 return ts;
611
612 err_remove_gpio:
613 ad7879_gpio_remove(ts);
614 err_remove_attr:
615 sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
616 err_free_irq:
617 free_irq(ts->irq, ts);
618 err_free_mem:
619 input_free_device(input_dev);
620 kfree(ts);
621 err_out:
622 return ERR_PTR(err);
623 }
624 EXPORT_SYMBOL(ad7879_probe);
625
626 void ad7879_remove(struct ad7879 *ts)
627 {
628 ad7879_gpio_remove(ts);
629 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
630 free_irq(ts->irq, ts);
631 input_unregister_device(ts->input);
632 kfree(ts);
633 }
634 EXPORT_SYMBOL(ad7879_remove);
635
636 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
637 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
638 MODULE_LICENSE("GPL");
linux-next