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[deliverable/linux.git] / drivers / input / touchscreen / ad7879.c
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
96 enum {
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
107 struct 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 #endif
116 unsigned int irq;
117 struct mutex mutex;
118 bool disabled; /* P: mutex */
119 u16 conversion_data[AD7879_NR_SENSE];
120 char phys[32];
121 u8 first_conversion_delay;
122 u8 acquisition_time;
123 u8 averaging;
124 u8 pen_down_acc_interval;
125 u8 median;
126 u16 x_plate_ohms;
127 u16 pressure_max;
128 u16 cmd_crtl1;
129 u16 cmd_crtl2;
130 u16 cmd_crtl3;
131 };
132
133 static int ad7879_read(struct ad7879 *ts, u8 reg)
134 {
135 return ts->bops->read(ts->dev, reg);
136 }
137
138 static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
139 {
140 return ts->bops->multi_read(ts->dev, first_reg, count, buf);
141 }
142
143 static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
144 {
145 return ts->bops->write(ts->dev, reg, val);
146 }
147
148 static void ad7879_report(struct ad7879 *ts)
149 {
150 struct input_dev *input_dev = ts->input;
151 unsigned Rt;
152 u16 x, y, z1, z2;
153
154 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
155 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
156 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
157 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
158
159 /*
160 * The samples processed here are already preprocessed by the AD7879.
161 * The preprocessing function consists of a median and an averaging
162 * filter. The combination of these two techniques provides a robust
163 * solution, discarding the spurious noise in the signal and keeping
164 * only the data of interest. The size of both filters is
165 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other
166 * user-programmable conversion controls include variable acquisition
167 * time, and first conversion delay. Up to 16 averages can be taken
168 * per conversion.
169 */
170
171 if (likely(x && z1)) {
172 /* compute touch pressure resistance using equation #1 */
173 Rt = (z2 - z1) * x * ts->x_plate_ohms;
174 Rt /= z1;
175 Rt = (Rt + 2047) >> 12;
176
177 input_report_abs(input_dev, ABS_X, x);
178 input_report_abs(input_dev, ABS_Y, y);
179 input_report_abs(input_dev, ABS_PRESSURE, Rt);
180 input_sync(input_dev);
181 }
182 }
183
184 static void ad7879_ts_event_release(struct ad7879 *ts)
185 {
186 struct input_dev *input_dev = ts->input;
187
188 input_report_abs(input_dev, ABS_PRESSURE, 0);
189 input_sync(input_dev);
190 }
191
192 static void ad7879_timer(unsigned long handle)
193 {
194 struct ad7879 *ts = (void *)handle;
195
196 ad7879_ts_event_release(ts);
197 }
198
199 static irqreturn_t ad7879_irq(int irq, void *handle)
200 {
201 struct ad7879 *ts = handle;
202
203 ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
204 ad7879_report(ts);
205
206 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
207
208 return IRQ_HANDLED;
209 }
210
211 static void ad7879_setup(struct ad7879 *ts)
212 {
213 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
214 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
215 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
216 }
217
218 void ad7879_disable(struct ad7879 *ts)
219 {
220 mutex_lock(&ts->mutex);
221
222 if (!ts->disabled) {
223
224 ts->disabled = true;
225 disable_irq(ts->irq);
226
227 if (del_timer_sync(&ts->timer))
228 ad7879_ts_event_release(ts);
229
230 ad7879_write(ts, AD7879_REG_CTRL2,
231 AD7879_PM(AD7879_PM_SHUTDOWN));
232 }
233
234 mutex_unlock(&ts->mutex);
235 }
236 EXPORT_SYMBOL(ad7879_disable);
237
238 void ad7879_enable(struct ad7879 *ts)
239 {
240 mutex_lock(&ts->mutex);
241
242 if (ts->disabled) {
243 ad7879_setup(ts);
244 ts->disabled = false;
245 enable_irq(ts->irq);
246 }
247
248 mutex_unlock(&ts->mutex);
249 }
250 EXPORT_SYMBOL(ad7879_enable);
251
252 static ssize_t ad7879_disable_show(struct device *dev,
253 struct device_attribute *attr, char *buf)
254 {
255 struct ad7879 *ts = dev_get_drvdata(dev);
256
257 return sprintf(buf, "%u\n", ts->disabled);
258 }
259
260 static ssize_t ad7879_disable_store(struct device *dev,
261 struct device_attribute *attr,
262 const char *buf, size_t count)
263 {
264 struct ad7879 *ts = dev_get_drvdata(dev);
265 unsigned long val;
266 int error;
267
268 error = strict_strtoul(buf, 10, &val);
269 if (error)
270 return error;
271
272 if (val)
273 ad7879_disable(ts);
274 else
275 ad7879_enable(ts);
276
277 return count;
278 }
279
280 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
281
282 static struct attribute *ad7879_attributes[] = {
283 &dev_attr_disable.attr,
284 NULL
285 };
286
287 static const struct attribute_group ad7879_attr_group = {
288 .attrs = ad7879_attributes,
289 };
290
291 #ifdef CONFIG_GPIOLIB
292 static int ad7879_gpio_direction_input(struct gpio_chip *chip,
293 unsigned gpio)
294 {
295 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
296 int err;
297
298 mutex_lock(&ts->mutex);
299 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
300 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
301 mutex_unlock(&ts->mutex);
302
303 return err;
304 }
305
306 static int ad7879_gpio_direction_output(struct gpio_chip *chip,
307 unsigned gpio, int level)
308 {
309 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
310 int err;
311
312 mutex_lock(&ts->mutex);
313 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
314 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
315 if (level)
316 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
317 else
318 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
319
320 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
321 mutex_unlock(&ts->mutex);
322
323 return err;
324 }
325
326 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
327 {
328 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
329 u16 val;
330
331 mutex_lock(&ts->mutex);
332 val = ad7879_read(ts, AD7879_REG_CTRL2);
333 mutex_unlock(&ts->mutex);
334
335 return !!(val & AD7879_GPIO_DATA);
336 }
337
338 static void ad7879_gpio_set_value(struct gpio_chip *chip,
339 unsigned gpio, int value)
340 {
341 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
342
343 mutex_lock(&ts->mutex);
344 if (value)
345 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
346 else
347 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
348
349 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
350 mutex_unlock(&ts->mutex);
351 }
352
353 static int ad7879_gpio_add(struct ad7879 *ts,
354 const struct ad7879_platform_data *pdata)
355 {
356 int ret = 0;
357
358 if (pdata->gpio_export) {
359 ts->gc.direction_input = ad7879_gpio_direction_input;
360 ts->gc.direction_output = ad7879_gpio_direction_output;
361 ts->gc.get = ad7879_gpio_get_value;
362 ts->gc.set = ad7879_gpio_set_value;
363 ts->gc.can_sleep = 1;
364 ts->gc.base = pdata->gpio_base;
365 ts->gc.ngpio = 1;
366 ts->gc.label = "AD7879-GPIO";
367 ts->gc.owner = THIS_MODULE;
368 ts->gc.dev = ts->dev;
369
370 ret = gpiochip_add(&ts->gc);
371 if (ret)
372 dev_err(ts->dev, "failed to register gpio %d\n",
373 ts->gc.base);
374 }
375
376 return ret;
377 }
378
379 static void ad7879_gpio_remove(struct ad7879 *ts)
380 {
381 const struct ad7879_platform_data *pdata = ts->dev->platform_data;
382 int ret;
383
384 if (pdata->gpio_export) {
385 ret = gpiochip_remove(&ts->gc);
386 if (ret)
387 dev_err(ts->dev, "failed to remove gpio %d\n",
388 ts->gc.base);
389 }
390 }
391 #else
392 static inline int ad7879_gpio_add(struct ad7879 *ts,
393 const struct ad7879_platform_data *pdata)
394 {
395 return 0;
396 }
397
398 static inline void ad7879_gpio_remove(struct ad7879 *ts)
399 {
400 }
401 #endif
402
403 struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
404 const struct ad7879_bus_ops *bops)
405 {
406 struct ad7879_platform_data *pdata = dev->platform_data;
407 struct ad7879 *ts;
408 struct input_dev *input_dev;
409 int err;
410 u16 revid;
411
412 if (!irq) {
413 dev_err(dev, "no IRQ?\n");
414 err = -EINVAL;
415 goto err_out;
416 }
417
418 if (!pdata) {
419 dev_err(dev, "no platform data?\n");
420 err = -EINVAL;
421 goto err_out;
422 }
423
424 ts = kzalloc(sizeof(*ts), GFP_KERNEL);
425 input_dev = input_allocate_device();
426 if (!ts || !input_dev) {
427 err = -ENOMEM;
428 goto err_free_mem;
429 }
430
431 ts->bops = bops;
432 ts->dev = dev;
433 ts->input = input_dev;
434
435 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
436 mutex_init(&ts->mutex);
437
438 ts->irq = irq;
439
440 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
441 ts->pressure_max = pdata->pressure_max ? : ~0;
442
443 ts->first_conversion_delay = pdata->first_conversion_delay;
444 ts->acquisition_time = pdata->acquisition_time;
445 ts->averaging = pdata->averaging;
446 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
447 ts->median = pdata->median;
448
449 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
450
451 input_dev->name = "AD7879 Touchscreen";
452 input_dev->phys = ts->phys;
453 input_dev->dev.parent = dev;
454 input_dev->id.bustype = bops->bustype;
455
456 __set_bit(EV_ABS, input_dev->evbit);
457 __set_bit(ABS_X, input_dev->absbit);
458 __set_bit(ABS_Y, input_dev->absbit);
459 __set_bit(ABS_PRESSURE, input_dev->absbit);
460
461 input_set_abs_params(input_dev, ABS_X,
462 pdata->x_min ? : 0,
463 pdata->x_max ? : MAX_12BIT,
464 0, 0);
465 input_set_abs_params(input_dev, ABS_Y,
466 pdata->y_min ? : 0,
467 pdata->y_max ? : MAX_12BIT,
468 0, 0);
469 input_set_abs_params(input_dev, ABS_PRESSURE,
470 pdata->pressure_min, pdata->pressure_max, 0, 0);
471
472 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
473 if (err < 0) {
474 dev_err(dev, "Failed to write %s\n", input_dev->name);
475 goto err_free_mem;
476 }
477
478 revid = ad7879_read(ts, AD7879_REG_REVID);
479 input_dev->id.product = (revid & 0xff);
480 input_dev->id.version = revid >> 8;
481 if (input_dev->id.product != devid) {
482 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
483 input_dev->name, devid, revid);
484 err = -ENODEV;
485 goto err_free_mem;
486 }
487
488 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
489 AD7879_XPLUS_BIT |
490 AD7879_Z2_BIT |
491 AD7879_Z1_BIT |
492 AD7879_TEMPMASK_BIT |
493 AD7879_AUXVBATMASK_BIT |
494 AD7879_GPIOALERTMASK_BIT;
495
496 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
497 AD7879_AVG(ts->averaging) |
498 AD7879_MFS(ts->median) |
499 AD7879_FCD(ts->first_conversion_delay);
500
501 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
502 AD7879_ACQ(ts->acquisition_time) |
503 AD7879_TMR(ts->pen_down_acc_interval);
504
505 ad7879_setup(ts);
506
507 err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
508 IRQF_TRIGGER_FALLING,
509 dev_name(dev), ts);
510 if (err) {
511 dev_err(dev, "irq %d busy?\n", ts->irq);
512 goto err_free_mem;
513 }
514
515 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
516 if (err)
517 goto err_free_irq;
518
519 err = ad7879_gpio_add(ts, pdata);
520 if (err)
521 goto err_remove_attr;
522
523 err = input_register_device(input_dev);
524 if (err)
525 goto err_remove_gpio;
526
527 return ts;
528
529 err_remove_gpio:
530 ad7879_gpio_remove(ts);
531 err_remove_attr:
532 sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
533 err_free_irq:
534 free_irq(ts->irq, ts);
535 err_free_mem:
536 input_free_device(input_dev);
537 kfree(ts);
538 err_out:
539 return ERR_PTR(err);
540 }
541 EXPORT_SYMBOL(ad7879_probe);
542
543 void ad7879_remove(struct ad7879 *ts)
544 {
545 ad7879_gpio_remove(ts);
546 ad7879_disable(ts);
547 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
548 free_irq(ts->irq, ts);
549 input_unregister_device(ts->input);
550 kfree(ts);
551 }
552 EXPORT_SYMBOL(ad7879_remove);
553
554 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
555 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
556 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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