1 /*
2 * Copyright (C) 2008 Michael Hennerich, Analog Devices Inc.
3 *
4 * Description: AD7879 based touchscreen, and GPIO driver (I2C/SPI Interface)
5 *
6 * Bugs: Enter bugs at http://blackfin.uclinux.org/
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, see the file COPYING, or write
20 * to the Free Software Foundation, Inc.,
21 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 *
23 * History:
24 * Copyright (c) 2005 David Brownell
25 * Copyright (c) 2006 Nokia Corporation
26 * Various changes: Imre Deak <imre.deak@nokia.com>
27 *
28 * Using code from:
29 * - corgi_ts.c
30 * Copyright (C) 2004-2005 Richard Purdie
31 * - omap_ts.[hc], ads7846.h, ts_osk.c
32 * Copyright (C) 2002 MontaVista Software
33 * Copyright (C) 2004 Texas Instruments
34 * Copyright (C) 2005 Dirk Behme
35 * - ad7877.c
36 * Copyright (C) 2006-2008 Analog Devices Inc.
37 */
38
39 #include <linux/device.h>
40 #include <linux/init.h>
41 #include <linux/delay.h>
42 #include <linux/input.h>
43 #include <linux/interrupt.h>
44 #include <linux/irq.h>
45 #include <linux/slab.h>
46 #include <linux/workqueue.h>
47 #include <linux/spi/spi.h>
48 #include <linux/i2c.h>
49
50 #include <linux/spi/ad7879.h>
51
52 #define AD7879_REG_ZEROS 0
53 #define AD7879_REG_CTRL1 1
54 #define AD7879_REG_CTRL2 2
55 #define AD7879_REG_CTRL3 3
56 #define AD7879_REG_AUX1HIGH 4
57 #define AD7879_REG_AUX1LOW 5
58 #define AD7879_REG_TEMP1HIGH 6
59 #define AD7879_REG_TEMP1LOW 7
60 #define AD7879_REG_XPLUS 8
61 #define AD7879_REG_YPLUS 9
62 #define AD7879_REG_Z1 10
63 #define AD7879_REG_Z2 11
64 #define AD7879_REG_AUXVBAT 12
65 #define AD7879_REG_TEMP 13
66 #define AD7879_REG_REVID 14
67
68 /* Control REG 1 */
69 #define AD7879_TMR(x) ((x & 0xFF) << 0)
70 #define AD7879_ACQ(x) ((x & 0x3) << 8)
71 #define AD7879_MODE_NOC (0 << 10) /* Do not convert */
72 #define AD7879_MODE_SCC (1 << 10) /* Single channel conversion */
73 #define AD7879_MODE_SEQ0 (2 << 10) /* Sequence 0 in Slave Mode */
74 #define AD7879_MODE_SEQ1 (3 << 10) /* Sequence 1 in Master Mode */
75 #define AD7879_MODE_INT (1 << 15) /* PENIRQ disabled INT enabled */
76
77 /* Control REG 2 */
78 #define AD7879_FCD(x) ((x & 0x3) << 0)
79 #define AD7879_RESET (1 << 4)
80 #define AD7879_MFS(x) ((x & 0x3) << 5)
81 #define AD7879_AVG(x) ((x & 0x3) << 7)
82 #define AD7879_SER (1 << 9) /* non-differential */
83 #define AD7879_DFR (0 << 9) /* differential */
84 #define AD7879_GPIOPOL (1 << 10)
85 #define AD7879_GPIODIR (1 << 11)
86 #define AD7879_GPIO_DATA (1 << 12)
87 #define AD7879_GPIO_EN (1 << 13)
88 #define AD7879_PM(x) ((x & 0x3) << 14)
89 #define AD7879_PM_SHUTDOWN (0)
90 #define AD7879_PM_DYN (1)
91 #define AD7879_PM_FULLON (2)
92
93 /* Control REG 3 */
94 #define AD7879_TEMPMASK_BIT (1<<15)
95 #define AD7879_AUXVBATMASK_BIT (1<<14)
96 #define AD7879_INTMODE_BIT (1<<13)
97 #define AD7879_GPIOALERTMASK_BIT (1<<12)
98 #define AD7879_AUXLOW_BIT (1<<11)
99 #define AD7879_AUXHIGH_BIT (1<<10)
100 #define AD7879_TEMPLOW_BIT (1<<9)
101 #define AD7879_TEMPHIGH_BIT (1<<8)
102 #define AD7879_YPLUS_BIT (1<<7)
103 #define AD7879_XPLUS_BIT (1<<6)
104 #define AD7879_Z1_BIT (1<<5)
105 #define AD7879_Z2_BIT (1<<4)
106 #define AD7879_AUX_BIT (1<<3)
107 #define AD7879_VBAT_BIT (1<<2)
108 #define AD7879_TEMP_BIT (1<<1)
109
110 enum {
111 AD7879_SEQ_XPOS = 0,
112 AD7879_SEQ_YPOS = 1,
113 AD7879_SEQ_Z1 = 2,
114 AD7879_SEQ_Z2 = 3,
115 AD7879_NR_SENSE = 4,
116 };
117
118 #define MAX_12BIT ((1<<12)-1)
119 #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)
120
121 #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
122 #define AD7879_DEVID 0x7A
123 typedef struct spi_device bus_device;
124 #elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE)
125 #define AD7879_DEVID 0x79
126 typedef struct i2c_client bus_device;
127 #endif
128
129 struct ad7879 {
130 bus_device *bus;
131 struct input_dev *input;
132 struct work_struct work;
133 struct timer_list timer;
134
135 struct mutex mutex;
136 unsigned disabled:1; /* P: mutex */
137
138 #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
139 struct spi_message msg;
140 struct spi_transfer xfer[AD7879_NR_SENSE + 1];
141 u16 cmd;
142 #endif
143 u16 conversion_data[AD7879_NR_SENSE];
144 char phys[32];
145 u8 first_conversion_delay;
146 u8 acquisition_time;
147 u8 averaging;
148 u8 pen_down_acc_interval;
149 u8 median;
150 u16 x_plate_ohms;
151 u16 pressure_max;
152 u16 gpio_init;
153 u16 cmd_crtl1;
154 u16 cmd_crtl2;
155 u16 cmd_crtl3;
156 unsigned gpio:1;
157 };
158
159 static int ad7879_read(bus_device *, u8);
160 static int ad7879_write(bus_device *, u8, u16);
161 static void ad7879_collect(struct ad7879 *);
162
163 static void ad7879_report(struct ad7879 *ts)
164 {
165 struct input_dev *input_dev = ts->input;
166 unsigned Rt;
167 u16 x, y, z1, z2;
168
169 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
170 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
171 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
172 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
173
174 /*
175 * The samples processed here are already preprocessed by the AD7879.
176 * The preprocessing function consists of a median and an averaging filter.
177 * The combination of these two techniques provides a robust solution,
178 * discarding the spurious noise in the signal and keeping only the data of interest.
179 * The size of both filters is programmable. (dev.platform_data, see linux/spi/ad7879.h)
180 * Other user-programmable conversion controls include variable acquisition time,
181 * and first conversion delay. Up to 16 averages can be taken per conversion.
182 */
183
184 if (likely(x && z1)) {
185 /* compute touch pressure resistance using equation #1 */
186 Rt = (z2 - z1) * x * ts->x_plate_ohms;
187 Rt /= z1;
188 Rt = (Rt + 2047) >> 12;
189
190 input_report_abs(input_dev, ABS_X, x);
191 input_report_abs(input_dev, ABS_Y, y);
192 input_report_abs(input_dev, ABS_PRESSURE, Rt);
193 input_sync(input_dev);
194 }
195 }
196
197 static void ad7879_work(struct work_struct *work)
198 {
199 struct ad7879 *ts = container_of(work, struct ad7879, work);
200
201 /* use keventd context to read the result registers */
202 ad7879_collect(ts);
203 ad7879_report(ts);
204 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
205 }
206
207 static void ad7879_ts_event_release(struct ad7879 *ts)
208 {
209 struct input_dev *input_dev = ts->input;
210
211 input_report_abs(input_dev, ABS_PRESSURE, 0);
212 input_sync(input_dev);
213 }
214
215 static void ad7879_timer(unsigned long handle)
216 {
217 struct ad7879 *ts = (void *)handle;
218
219 ad7879_ts_event_release(ts);
220 }
221
222 static irqreturn_t ad7879_irq(int irq, void *handle)
223 {
224 struct ad7879 *ts = handle;
225
226 /* The repeated conversion sequencer controlled by TMR kicked off too fast.
227 * We ignore the last and process the sample sequence currently in the queue.
228 * It can't be older than 9.4ms
229 */
230
231 if (!work_pending(&ts->work))
232 schedule_work(&ts->work);
233
234 return IRQ_HANDLED;
235 }
236
237 static void ad7879_setup(struct ad7879 *ts)
238 {
239 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
240 AD7879_XPLUS_BIT |
241 AD7879_Z2_BIT |
242 AD7879_Z1_BIT |
243 AD7879_TEMPMASK_BIT |
244 AD7879_AUXVBATMASK_BIT |
245 AD7879_GPIOALERTMASK_BIT;
246
247 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
248 AD7879_AVG(ts->averaging) |
249 AD7879_MFS(ts->median) |
250 AD7879_FCD(ts->first_conversion_delay) |
251 ts->gpio_init;
252
253 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
254 AD7879_ACQ(ts->acquisition_time) |
255 AD7879_TMR(ts->pen_down_acc_interval);
256
257 ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
258 ad7879_write(ts->bus, AD7879_REG_CTRL3, ts->cmd_crtl3);
259 ad7879_write(ts->bus, AD7879_REG_CTRL1, ts->cmd_crtl1);
260 }
261
262 static void ad7879_disable(struct ad7879 *ts)
263 {
264 mutex_lock(&ts->mutex);
265
266 if (!ts->disabled) {
267
268 ts->disabled = 1;
269 disable_irq(ts->bus->irq);
270
271 cancel_work_sync(&ts->work);
272
273 if (del_timer_sync(&ts->timer))
274 ad7879_ts_event_release(ts);
275
276 ad7879_write(ts->bus, AD7879_REG_CTRL2,
277 AD7879_PM(AD7879_PM_SHUTDOWN));
278 }
279
280 mutex_unlock(&ts->mutex);
281 }
282
283 static void ad7879_enable(struct ad7879 *ts)
284 {
285 mutex_lock(&ts->mutex);
286
287 if (ts->disabled) {
288 ad7879_setup(ts);
289 ts->disabled = 0;
290 enable_irq(ts->bus->irq);
291 }
292
293 mutex_unlock(&ts->mutex);
294 }
295
296 static ssize_t ad7879_disable_show(struct device *dev,
297 struct device_attribute *attr, char *buf)
298 {
299 struct ad7879 *ts = dev_get_drvdata(dev);
300
301 return sprintf(buf, "%u\n", ts->disabled);
302 }
303
304 static ssize_t ad7879_disable_store(struct device *dev,
305 struct device_attribute *attr,
306 const char *buf, size_t count)
307 {
308 struct ad7879 *ts = dev_get_drvdata(dev);
309 unsigned long val;
310 int error;
311
312 error = strict_strtoul(buf, 10, &val);
313 if (error)
314 return error;
315
316 if (val)
317 ad7879_disable(ts);
318 else
319 ad7879_enable(ts);
320
321 return count;
322 }
323
324 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
325
326 static ssize_t ad7879_gpio_show(struct device *dev,
327 struct device_attribute *attr, char *buf)
328 {
329 struct ad7879 *ts = dev_get_drvdata(dev);
330
331 return sprintf(buf, "%u\n", ts->gpio);
332 }
333
334 static ssize_t ad7879_gpio_store(struct device *dev,
335 struct device_attribute *attr,
336 const char *buf, size_t count)
337 {
338 struct ad7879 *ts = dev_get_drvdata(dev);
339 unsigned long val;
340 int error;
341
342 error = strict_strtoul(buf, 10, &val);
343 if (error)
344 return error;
345
346 mutex_lock(&ts->mutex);
347 ts->gpio = !!val;
348 error = ad7879_write(ts->bus, AD7879_REG_CTRL2,
349 ts->gpio ?
350 ts->cmd_crtl2 & ~AD7879_GPIO_DATA :
351 ts->cmd_crtl2 | AD7879_GPIO_DATA);
352 mutex_unlock(&ts->mutex);
353
354 return error ? : count;
355 }
356
357 static DEVICE_ATTR(gpio, 0664, ad7879_gpio_show, ad7879_gpio_store);
358
359 static struct attribute *ad7879_attributes[] = {
360 &dev_attr_disable.attr,
361 &dev_attr_gpio.attr,
362 NULL
363 };
364
365 static const struct attribute_group ad7879_attr_group = {
366 .attrs = ad7879_attributes,
367 };
368
369 static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
370 {
371 struct input_dev *input_dev;
372 struct ad7879_platform_data *pdata = bus->dev.platform_data;
373 int err;
374 u16 revid;
375
376 if (!bus->irq) {
377 dev_err(&bus->dev, "no IRQ?\n");
378 return -ENODEV;
379 }
380
381 if (!pdata) {
382 dev_err(&bus->dev, "no platform data?\n");
383 return -ENODEV;
384 }
385
386 input_dev = input_allocate_device();
387 if (!input_dev)
388 return -ENOMEM;
389
390 ts->input = input_dev;
391
392 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
393 INIT_WORK(&ts->work, ad7879_work);
394 mutex_init(&ts->mutex);
395
396 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
397 ts->pressure_max = pdata->pressure_max ? : ~0;
398
399 ts->first_conversion_delay = pdata->first_conversion_delay;
400 ts->acquisition_time = pdata->acquisition_time;
401 ts->averaging = pdata->averaging;
402 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
403 ts->median = pdata->median;
404
405 if (pdata->gpio_output)
406 ts->gpio_init = AD7879_GPIO_EN |
407 (pdata->gpio_default ? 0 : AD7879_GPIO_DATA);
408 else
409 ts->gpio_init = AD7879_GPIO_EN | AD7879_GPIODIR;
410
411 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&bus->dev));
412
413 input_dev->name = "AD7879 Touchscreen";
414 input_dev->phys = ts->phys;
415 input_dev->dev.parent = &bus->dev;
416
417 __set_bit(EV_ABS, input_dev->evbit);
418 __set_bit(ABS_X, input_dev->absbit);
419 __set_bit(ABS_Y, input_dev->absbit);
420 __set_bit(ABS_PRESSURE, input_dev->absbit);
421
422 input_set_abs_params(input_dev, ABS_X,
423 pdata->x_min ? : 0,
424 pdata->x_max ? : MAX_12BIT,
425 0, 0);
426 input_set_abs_params(input_dev, ABS_Y,
427 pdata->y_min ? : 0,
428 pdata->y_max ? : MAX_12BIT,
429 0, 0);
430 input_set_abs_params(input_dev, ABS_PRESSURE,
431 pdata->pressure_min, pdata->pressure_max, 0, 0);
432
433 err = ad7879_write(bus, AD7879_REG_CTRL2, AD7879_RESET);
434
435 if (err < 0) {
436 dev_err(&bus->dev, "Failed to write %s\n", input_dev->name);
437 goto err_free_mem;
438 }
439
440 revid = ad7879_read(bus, AD7879_REG_REVID);
441
442 if ((revid & 0xFF) != AD7879_DEVID) {
443 dev_err(&bus->dev, "Failed to probe %s\n", input_dev->name);
444 err = -ENODEV;
445 goto err_free_mem;
446 }
447
448 ad7879_setup(ts);
449
450 err = request_irq(bus->irq, ad7879_irq,
451 IRQF_TRIGGER_FALLING, bus->dev.driver->name, ts);
452
453 if (err) {
454 dev_err(&bus->dev, "irq %d busy?\n", bus->irq);
455 goto err_free_mem;
456 }
457
458 err = sysfs_create_group(&bus->dev.kobj, &ad7879_attr_group);
459 if (err)
460 goto err_free_irq;
461
462 err = input_register_device(input_dev);
463 if (err)
464 goto err_remove_attr;
465
466 dev_info(&bus->dev, "Rev.%d touchscreen, irq %d\n",
467 revid >> 8, bus->irq);
468
469 return 0;
470
471 err_remove_attr:
472 sysfs_remove_group(&bus->dev.kobj, &ad7879_attr_group);
473 err_free_irq:
474 free_irq(bus->irq, ts);
475 err_free_mem:
476 input_free_device(input_dev);
477
478 return err;
479 }
480
481 static int __devexit ad7879_destroy(bus_device *bus, struct ad7879 *ts)
482 {
483 ad7879_disable(ts);
484 sysfs_remove_group(&ts->bus->dev.kobj, &ad7879_attr_group);
485 free_irq(ts->bus->irq, ts);
486 input_unregister_device(ts->input);
487 dev_dbg(&bus->dev, "unregistered touchscreen\n");
488
489 return 0;
490 }
491
492 #ifdef CONFIG_PM
493 static int ad7879_suspend(bus_device *bus, pm_message_t message)
494 {
495 struct ad7879 *ts = dev_get_drvdata(&bus->dev);
496
497 ad7879_disable(ts);
498
499 return 0;
500 }
501
502 static int ad7879_resume(bus_device *bus)
503 {
504 struct ad7879 *ts = dev_get_drvdata(&bus->dev);
505
506 ad7879_enable(ts);
507
508 return 0;
509 }
510 #else
511 #define ad7879_suspend NULL
512 #define ad7879_resume NULL
513 #endif
514
515 #if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
516 #define MAX_SPI_FREQ_HZ 5000000
517 #define AD7879_CMD_MAGIC 0xE000
518 #define AD7879_CMD_READ (1 << 10)
519 #define AD7879_WRITECMD(reg) (AD7879_CMD_MAGIC | (reg & 0xF))
520 #define AD7879_READCMD(reg) (AD7879_CMD_MAGIC | AD7879_CMD_READ | (reg & 0xF))
521
522 struct ser_req {
523 u16 command;
524 u16 data;
525 struct spi_message msg;
526 struct spi_transfer xfer[2];
527 };
528
529 /*
530 * ad7879_read/write are only used for initial setup and for sysfs controls.
531 * The main traffic is done in ad7879_collect().
532 */
533
534 static int ad7879_read(struct spi_device *spi, u8 reg)
535 {
536 struct ser_req *req;
537 int status, ret;
538
539 req = kzalloc(sizeof *req, GFP_KERNEL);
540 if (!req)
541 return -ENOMEM;
542
543 spi_message_init(&req->msg);
544
545 req->command = (u16) AD7879_READCMD(reg);
546 req->xfer[0].tx_buf = &req->command;
547 req->xfer[0].len = 2;
548
549 req->xfer[1].rx_buf = &req->data;
550 req->xfer[1].len = 2;
551
552 spi_message_add_tail(&req->xfer[0], &req->msg);
553 spi_message_add_tail(&req->xfer[1], &req->msg);
554
555 status = spi_sync(spi, &req->msg);
556 ret = status ? : req->data;
557
558 kfree(req);
559
560 return ret;
561 }
562
563 static int ad7879_write(struct spi_device *spi, u8 reg, u16 val)
564 {
565 struct ser_req *req;
566 int status;
567
568 req = kzalloc(sizeof *req, GFP_KERNEL);
569 if (!req)
570 return -ENOMEM;
571
572 spi_message_init(&req->msg);
573
574 req->command = (u16) AD7879_WRITECMD(reg);
575 req->xfer[0].tx_buf = &req->command;
576 req->xfer[0].len = 2;
577
578 req->data = val;
579 req->xfer[1].tx_buf = &req->data;
580 req->xfer[1].len = 2;
581
582 spi_message_add_tail(&req->xfer[0], &req->msg);
583 spi_message_add_tail(&req->xfer[1], &req->msg);
584
585 status = spi_sync(spi, &req->msg);
586
587 kfree(req);
588
589 return status;
590 }
591
592 static void ad7879_collect(struct ad7879 *ts)
593 {
594 int status = spi_sync(ts->bus, &ts->msg);
595
596 if (status)
597 dev_err(&ts->bus->dev, "spi_sync --> %d\n", status);
598 }
599
600 static void ad7879_setup_ts_def_msg(struct ad7879 *ts)
601 {
602 struct spi_message *m;
603 int i;
604
605 ts->cmd = (u16) AD7879_READCMD(AD7879_REG_XPLUS);
606
607 m = &ts->msg;
608 spi_message_init(m);
609 ts->xfer[0].tx_buf = &ts->cmd;
610 ts->xfer[0].len = 2;
611
612 spi_message_add_tail(&ts->xfer[0], m);
613
614 for (i = 0; i < AD7879_NR_SENSE; i++) {
615 ts->xfer[i + 1].rx_buf = &ts->conversion_data[i];
616 ts->xfer[i + 1].len = 2;
617 spi_message_add_tail(&ts->xfer[i + 1], m);
618 }
619 }
620
621 static int __devinit ad7879_probe(struct spi_device *spi)
622 {
623 struct ad7879 *ts;
624 int error;
625
626 /* don't exceed max specified SPI CLK frequency */
627 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
628 dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
629 return -EINVAL;
630 }
631
632 ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
633 if (!ts)
634 return -ENOMEM;
635
636 dev_set_drvdata(&spi->dev, ts);
637 ts->bus = spi;
638
639 ad7879_setup_ts_def_msg(ts);
640
641 error = ad7879_construct(spi, ts);
642 if (error) {
643 dev_set_drvdata(&spi->dev, NULL);
644 kfree(ts);
645 }
646
647 return 0;
648 }
649
650 static int __devexit ad7879_remove(struct spi_device *spi)
651 {
652 struct ad7879 *ts = dev_get_drvdata(&spi->dev);
653
654 ad7879_destroy(spi, ts);
655 dev_set_drvdata(&spi->dev, NULL);
656 kfree(ts);
657
658 return 0;
659 }
660
661 static struct spi_driver ad7879_driver = {
662 .driver = {
663 .name = "ad7879",
664 .bus = &spi_bus_type,
665 .owner = THIS_MODULE,
666 },
667 .probe = ad7879_probe,
668 .remove = __devexit_p(ad7879_remove),
669 .suspend = ad7879_suspend,
670 .resume = ad7879_resume,
671 };
672
673 static int __init ad7879_init(void)
674 {
675 return spi_register_driver(&ad7879_driver);
676 }
677 module_init(ad7879_init);
678
679 static void __exit ad7879_exit(void)
680 {
681 spi_unregister_driver(&ad7879_driver);
682 }
683 module_exit(ad7879_exit);
684
685 #elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE)
686
687 /* All registers are word-sized.
688 * AD7879 uses a high-byte first convention.
689 */
690 static int ad7879_read(struct i2c_client *client, u8 reg)
691 {
692 return swab16(i2c_smbus_read_word_data(client, reg));
693 }
694
695 static int ad7879_write(struct i2c_client *client, u8 reg, u16 val)
696 {
697 return i2c_smbus_write_word_data(client, reg, swab16(val));
698 }
699
700 static void ad7879_collect(struct ad7879 *ts)
701 {
702 int i;
703
704 for (i = 0; i < AD7879_NR_SENSE; i++)
705 ts->conversion_data[i] = ad7879_read(ts->bus,
706 AD7879_REG_XPLUS + i);
707 }
708
709 static int __devinit ad7879_probe(struct i2c_client *client,
710 const struct i2c_device_id *id)
711 {
712 struct ad7879 *ts;
713 int error;
714
715 if (!i2c_check_functionality(client->adapter,
716 I2C_FUNC_SMBUS_WORD_DATA)) {
717 dev_err(&client->dev, "SMBUS Word Data not Supported\n");
718 return -EIO;
719 }
720
721 ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
722 if (!ts)
723 return -ENOMEM;
724
725 i2c_set_clientdata(client, ts);
726 ts->bus = client;
727
728 error = ad7879_construct(client, ts);
729 if (error) {
730 i2c_set_clientdata(client, NULL);
731 kfree(ts);
732 }
733
734 return 0;
735 }
736
737 static int __devexit ad7879_remove(struct i2c_client *client)
738 {
739 struct ad7879 *ts = dev_get_drvdata(&client->dev);
740
741 ad7879_destroy(client, ts);
742 i2c_set_clientdata(client, NULL);
743 kfree(ts);
744
745 return 0;
746 }
747
748 static const struct i2c_device_id ad7879_id[] = {
749 { "ad7879", 0 },
750 { }
751 };
752 MODULE_DEVICE_TABLE(i2c, ad7879_id);
753
754 static struct i2c_driver ad7879_driver = {
755 .driver = {
756 .name = "ad7879",
757 .owner = THIS_MODULE,
758 },
759 .probe = ad7879_probe,
760 .remove = __devexit_p(ad7879_remove),
761 .suspend = ad7879_suspend,
762 .resume = ad7879_resume,
763 .id_table = ad7879_id,
764 };
765
766 static int __init ad7879_init(void)
767 {
768 return i2c_add_driver(&ad7879_driver);
769 }
770 module_init(ad7879_init);
771
772 static void __exit ad7879_exit(void)
773 {
774 i2c_del_driver(&ad7879_driver);
775 }
776 module_exit(ad7879_exit);
777 #endif
778
779 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
780 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
781 MODULE_LICENSE("GPL");
782
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