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1/*
2 * Copyright (C) 2006-2008 Michael Hennerich, Analog Devices Inc.
3 *
4 * Description: AD7877 based touchscreen, sensor (ADCs), DAC and GPIO driver
5 * Based on: ads7846.c
6 *
7 * Bugs: Enter bugs at http://blackfin.uclinux.org/
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, see the file COPYING, or write
21 * to the Free Software Foundation, Inc.,
22 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 *
24 * History:
25 * Copyright (c) 2005 David Brownell
26 * Copyright (c) 2006 Nokia Corporation
27 * Various changes: Imre Deak <imre.deak@nokia.com>
28 *
29 * Using code from:
30 * - corgi_ts.c
31 * Copyright (C) 2004-2005 Richard Purdie
32 * - omap_ts.[hc], ads7846.h, ts_osk.c
33 * Copyright (C) 2002 MontaVista Software
34 * Copyright (C) 2004 Texas Instruments
35 * Copyright (C) 2005 Dirk Behme
36 */
37
38
39#include <linux/device.h>
40#include <linux/delay.h>
41#include <linux/input.h>
42#include <linux/interrupt.h>
43#include <linux/pm.h>
44#include <linux/slab.h>
45#include <linux/spi/spi.h>
46#include <linux/spi/ad7877.h>
47#include <linux/module.h>
48#include <asm/irq.h>
49
50#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(100)
51
52#define MAX_SPI_FREQ_HZ 20000000
53#define MAX_12BIT ((1<<12)-1)
54
55#define AD7877_REG_ZEROS 0
56#define AD7877_REG_CTRL1 1
57#define AD7877_REG_CTRL2 2
58#define AD7877_REG_ALERT 3
59#define AD7877_REG_AUX1HIGH 4
60#define AD7877_REG_AUX1LOW 5
61#define AD7877_REG_BAT1HIGH 6
62#define AD7877_REG_BAT1LOW 7
63#define AD7877_REG_BAT2HIGH 8
64#define AD7877_REG_BAT2LOW 9
65#define AD7877_REG_TEMP1HIGH 10
66#define AD7877_REG_TEMP1LOW 11
67#define AD7877_REG_SEQ0 12
68#define AD7877_REG_SEQ1 13
69#define AD7877_REG_DAC 14
70#define AD7877_REG_NONE1 15
71#define AD7877_REG_EXTWRITE 15
72#define AD7877_REG_XPLUS 16
73#define AD7877_REG_YPLUS 17
74#define AD7877_REG_Z2 18
75#define AD7877_REG_aux1 19
76#define AD7877_REG_aux2 20
77#define AD7877_REG_aux3 21
78#define AD7877_REG_bat1 22
79#define AD7877_REG_bat2 23
80#define AD7877_REG_temp1 24
81#define AD7877_REG_temp2 25
82#define AD7877_REG_Z1 26
83#define AD7877_REG_GPIOCTRL1 27
84#define AD7877_REG_GPIOCTRL2 28
85#define AD7877_REG_GPIODATA 29
86#define AD7877_REG_NONE2 30
87#define AD7877_REG_NONE3 31
88
89#define AD7877_SEQ_YPLUS_BIT (1<<11)
90#define AD7877_SEQ_XPLUS_BIT (1<<10)
91#define AD7877_SEQ_Z2_BIT (1<<9)
92#define AD7877_SEQ_AUX1_BIT (1<<8)
93#define AD7877_SEQ_AUX2_BIT (1<<7)
94#define AD7877_SEQ_AUX3_BIT (1<<6)
95#define AD7877_SEQ_BAT1_BIT (1<<5)
96#define AD7877_SEQ_BAT2_BIT (1<<4)
97#define AD7877_SEQ_TEMP1_BIT (1<<3)
98#define AD7877_SEQ_TEMP2_BIT (1<<2)
99#define AD7877_SEQ_Z1_BIT (1<<1)
100
101enum {
102 AD7877_SEQ_YPOS = 0,
103 AD7877_SEQ_XPOS = 1,
104 AD7877_SEQ_Z2 = 2,
105 AD7877_SEQ_AUX1 = 3,
106 AD7877_SEQ_AUX2 = 4,
107 AD7877_SEQ_AUX3 = 5,
108 AD7877_SEQ_BAT1 = 6,
109 AD7877_SEQ_BAT2 = 7,
110 AD7877_SEQ_TEMP1 = 8,
111 AD7877_SEQ_TEMP2 = 9,
112 AD7877_SEQ_Z1 = 10,
113 AD7877_NR_SENSE = 11,
114};
115
116/* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */
117#define AD7877_DAC_CONF 0x1
118
119/* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */
120#define AD7877_EXTW_GPIO_3_CONF 0x1C4
121#define AD7877_EXTW_GPIO_DATA 0x200
122
123/* Control REG 2 */
124#define AD7877_TMR(x) ((x & 0x3) << 0)
125#define AD7877_REF(x) ((x & 0x1) << 2)
126#define AD7877_POL(x) ((x & 0x1) << 3)
127#define AD7877_FCD(x) ((x & 0x3) << 4)
128#define AD7877_PM(x) ((x & 0x3) << 6)
129#define AD7877_ACQ(x) ((x & 0x3) << 8)
130#define AD7877_AVG(x) ((x & 0x3) << 10)
131
132/* Control REG 1 */
133#define AD7877_SER (1 << 11) /* non-differential */
134#define AD7877_DFR (0 << 11) /* differential */
135
136#define AD7877_MODE_NOC (0) /* Do not convert */
137#define AD7877_MODE_SCC (1) /* Single channel conversion */
138#define AD7877_MODE_SEQ0 (2) /* Sequence 0 in Slave Mode */
139#define AD7877_MODE_SEQ1 (3) /* Sequence 1 in Master Mode */
140
141#define AD7877_CHANADD(x) ((x&0xF)<<7)
142#define AD7877_READADD(x) ((x)<<2)
143#define AD7877_WRITEADD(x) ((x)<<12)
144
145#define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \
146 AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \
147 AD7877_READADD(AD7877_REG_ ## x))
148
149#define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \
150 AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT)
151
152/*
153 * Non-touchscreen sensors only use single-ended conversions.
154 */
155
156struct ser_req {
157 u16 reset;
158 u16 ref_on;
159 u16 command;
160 struct spi_message msg;
161 struct spi_transfer xfer[6];
162
163 /*
164 * DMA (thus cache coherency maintenance) requires the
165 * transfer buffers to live in their own cache lines.
166 */
167 u16 sample ____cacheline_aligned;
168};
169
170struct ad7877 {
171 struct input_dev *input;
172 char phys[32];
173
174 struct spi_device *spi;
175 u16 model;
176 u16 vref_delay_usecs;
177 u16 x_plate_ohms;
178 u16 pressure_max;
179
180 u16 cmd_crtl1;
181 u16 cmd_crtl2;
182 u16 cmd_dummy;
183 u16 dac;
184
185 u8 stopacq_polarity;
186 u8 first_conversion_delay;
187 u8 acquisition_time;
188 u8 averaging;
189 u8 pen_down_acc_interval;
190
191 struct spi_transfer xfer[AD7877_NR_SENSE + 2];
192 struct spi_message msg;
193
194 struct mutex mutex;
195 bool disabled; /* P: mutex */
196 bool gpio3; /* P: mutex */
197 bool gpio4; /* P: mutex */
198
199 spinlock_t lock;
200 struct timer_list timer; /* P: lock */
201
202 /*
203 * DMA (thus cache coherency maintenance) requires the
204 * transfer buffers to live in their own cache lines.
205 */
206 u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned;
207};
208
209static bool gpio3;
210module_param(gpio3, bool, 0);
211MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
212
213/*
214 * ad7877_read/write are only used for initial setup and for sysfs controls.
215 * The main traffic is done using spi_async() in the interrupt handler.
216 */
217
218static int ad7877_read(struct spi_device *spi, u16 reg)
219{
220 struct ser_req *req;
221 int status, ret;
222
223 req = kzalloc(sizeof *req, GFP_KERNEL);
224 if (!req)
225 return -ENOMEM;
226
227 spi_message_init(&req->msg);
228
229 req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) |
230 AD7877_READADD(reg));
231 req->xfer[0].tx_buf = &req->command;
232 req->xfer[0].len = 2;
233 req->xfer[0].cs_change = 1;
234
235 req->xfer[1].rx_buf = &req->sample;
236 req->xfer[1].len = 2;
237
238 spi_message_add_tail(&req->xfer[0], &req->msg);
239 spi_message_add_tail(&req->xfer[1], &req->msg);
240
241 status = spi_sync(spi, &req->msg);
242 ret = status ? : req->sample;
243
244 kfree(req);
245
246 return ret;
247}
248
249static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
250{
251 struct ser_req *req;
252 int status;
253
254 req = kzalloc(sizeof *req, GFP_KERNEL);
255 if (!req)
256 return -ENOMEM;
257
258 spi_message_init(&req->msg);
259
260 req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
261 req->xfer[0].tx_buf = &req->command;
262 req->xfer[0].len = 2;
263
264 spi_message_add_tail(&req->xfer[0], &req->msg);
265
266 status = spi_sync(spi, &req->msg);
267
268 kfree(req);
269
270 return status;
271}
272
273static int ad7877_read_adc(struct spi_device *spi, unsigned command)
274{
275 struct ad7877 *ts = spi_get_drvdata(spi);
276 struct ser_req *req;
277 int status;
278 int sample;
279 int i;
280
281 req = kzalloc(sizeof *req, GFP_KERNEL);
282 if (!req)
283 return -ENOMEM;
284
285 spi_message_init(&req->msg);
286
287 /* activate reference, so it has time to settle; */
288 req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) |
289 AD7877_POL(ts->stopacq_polarity) |
290 AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) |
291 AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0);
292
293 req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
294
295 req->command = (u16) command;
296
297 req->xfer[0].tx_buf = &req->reset;
298 req->xfer[0].len = 2;
299 req->xfer[0].cs_change = 1;
300
301 req->xfer[1].tx_buf = &req->ref_on;
302 req->xfer[1].len = 2;
303 req->xfer[1].delay_usecs = ts->vref_delay_usecs;
304 req->xfer[1].cs_change = 1;
305
306 req->xfer[2].tx_buf = &req->command;
307 req->xfer[2].len = 2;
308 req->xfer[2].delay_usecs = ts->vref_delay_usecs;
309 req->xfer[2].cs_change = 1;
310
311 req->xfer[3].rx_buf = &req->sample;
312 req->xfer[3].len = 2;
313 req->xfer[3].cs_change = 1;
314
315 req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/
316 req->xfer[4].len = 2;
317 req->xfer[4].cs_change = 1;
318
319 req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/
320 req->xfer[5].len = 2;
321
322 /* group all the transfers together, so we can't interfere with
323 * reading touchscreen state; disable penirq while sampling
324 */
325 for (i = 0; i < 6; i++)
326 spi_message_add_tail(&req->xfer[i], &req->msg);
327
328 status = spi_sync(spi, &req->msg);
329 sample = req->sample;
330
331 kfree(req);
332
333 return status ? : sample;
334}
335
336static int ad7877_process_data(struct ad7877 *ts)
337{
338 struct input_dev *input_dev = ts->input;
339 unsigned Rt;
340 u16 x, y, z1, z2;
341
342 x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
343 y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
344 z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
345 z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
346
347 /*
348 * The samples processed here are already preprocessed by the AD7877.
349 * The preprocessing function consists of an averaging filter.
350 * The combination of 'first conversion delay' and averaging provides a robust solution,
351 * discarding the spurious noise in the signal and keeping only the data of interest.
352 * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h)
353 * Other user-programmable conversion controls include variable acquisition time,
354 * and first conversion delay. Up to 16 averages can be taken per conversion.
355 */
356
357 if (likely(x && z1)) {
358 /* compute touch pressure resistance using equation #1 */
359 Rt = (z2 - z1) * x * ts->x_plate_ohms;
360 Rt /= z1;
361 Rt = (Rt + 2047) >> 12;
362
363 /*
364 * Sample found inconsistent, pressure is beyond
365 * the maximum. Don't report it to user space.
366 */
367 if (Rt > ts->pressure_max)
368 return -EINVAL;
369
370 if (!timer_pending(&ts->timer))
371 input_report_key(input_dev, BTN_TOUCH, 1);
372
373 input_report_abs(input_dev, ABS_X, x);
374 input_report_abs(input_dev, ABS_Y, y);
375 input_report_abs(input_dev, ABS_PRESSURE, Rt);
376 input_sync(input_dev);
377
378 return 0;
379 }
380
381 return -EINVAL;
382}
383
384static inline void ad7877_ts_event_release(struct ad7877 *ts)
385{
386 struct input_dev *input_dev = ts->input;
387
388 input_report_abs(input_dev, ABS_PRESSURE, 0);
389 input_report_key(input_dev, BTN_TOUCH, 0);
390 input_sync(input_dev);
391}
392
393static void ad7877_timer(unsigned long handle)
394{
395 struct ad7877 *ts = (void *)handle;
396 unsigned long flags;
397
398 spin_lock_irqsave(&ts->lock, flags);
399 ad7877_ts_event_release(ts);
400 spin_unlock_irqrestore(&ts->lock, flags);
401}
402
403static irqreturn_t ad7877_irq(int irq, void *handle)
404{
405 struct ad7877 *ts = handle;
406 unsigned long flags;
407 int error;
408
409 error = spi_sync(ts->spi, &ts->msg);
410 if (error) {
411 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
412 goto out;
413 }
414
415 spin_lock_irqsave(&ts->lock, flags);
416 error = ad7877_process_data(ts);
417 if (!error)
418 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
419 spin_unlock_irqrestore(&ts->lock, flags);
420
421out:
422 return IRQ_HANDLED;
423}
424
425static void ad7877_disable(struct ad7877 *ts)
426{
427 mutex_lock(&ts->mutex);
428
429 if (!ts->disabled) {
430 ts->disabled = true;
431 disable_irq(ts->spi->irq);
432
433 if (del_timer_sync(&ts->timer))
434 ad7877_ts_event_release(ts);
435 }
436
437 /*
438 * We know the chip's in lowpower mode since we always
439 * leave it that way after every request
440 */
441
442 mutex_unlock(&ts->mutex);
443}
444
445static void ad7877_enable(struct ad7877 *ts)
446{
447 mutex_lock(&ts->mutex);
448
449 if (ts->disabled) {
450 ts->disabled = false;
451 enable_irq(ts->spi->irq);
452 }
453
454 mutex_unlock(&ts->mutex);
455}
456
457#define SHOW(name) static ssize_t \
458name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
459{ \
460 struct ad7877 *ts = dev_get_drvdata(dev); \
461 ssize_t v = ad7877_read_adc(ts->spi, \
462 AD7877_READ_CHAN(name)); \
463 if (v < 0) \
464 return v; \
465 return sprintf(buf, "%u\n", (unsigned) v); \
466} \
467static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
468
469SHOW(aux1)
470SHOW(aux2)
471SHOW(aux3)
472SHOW(bat1)
473SHOW(bat2)
474SHOW(temp1)
475SHOW(temp2)
476
477static ssize_t ad7877_disable_show(struct device *dev,
478 struct device_attribute *attr, char *buf)
479{
480 struct ad7877 *ts = dev_get_drvdata(dev);
481
482 return sprintf(buf, "%u\n", ts->disabled);
483}
484
485static ssize_t ad7877_disable_store(struct device *dev,
486 struct device_attribute *attr,
487 const char *buf, size_t count)
488{
489 struct ad7877 *ts = dev_get_drvdata(dev);
490 unsigned int val;
491 int error;
492
493 error = kstrtouint(buf, 10, &val);
494 if (error)
495 return error;
496
497 if (val)
498 ad7877_disable(ts);
499 else
500 ad7877_enable(ts);
501
502 return count;
503}
504
505static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
506
507static ssize_t ad7877_dac_show(struct device *dev,
508 struct device_attribute *attr, char *buf)
509{
510 struct ad7877 *ts = dev_get_drvdata(dev);
511
512 return sprintf(buf, "%u\n", ts->dac);
513}
514
515static ssize_t ad7877_dac_store(struct device *dev,
516 struct device_attribute *attr,
517 const char *buf, size_t count)
518{
519 struct ad7877 *ts = dev_get_drvdata(dev);
520 unsigned int val;
521 int error;
522
523 error = kstrtouint(buf, 10, &val);
524 if (error)
525 return error;
526
527 mutex_lock(&ts->mutex);
528 ts->dac = val & 0xFF;
529 ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
530 mutex_unlock(&ts->mutex);
531
532 return count;
533}
534
535static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
536
537static ssize_t ad7877_gpio3_show(struct device *dev,
538 struct device_attribute *attr, char *buf)
539{
540 struct ad7877 *ts = dev_get_drvdata(dev);
541
542 return sprintf(buf, "%u\n", ts->gpio3);
543}
544
545static ssize_t ad7877_gpio3_store(struct device *dev,
546 struct device_attribute *attr,
547 const char *buf, size_t count)
548{
549 struct ad7877 *ts = dev_get_drvdata(dev);
550 unsigned int val;
551 int error;
552
553 error = kstrtouint(buf, 10, &val);
554 if (error)
555 return error;
556
557 mutex_lock(&ts->mutex);
558 ts->gpio3 = !!val;
559 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
560 (ts->gpio4 << 4) | (ts->gpio3 << 5));
561 mutex_unlock(&ts->mutex);
562
563 return count;
564}
565
566static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
567
568static ssize_t ad7877_gpio4_show(struct device *dev,
569 struct device_attribute *attr, char *buf)
570{
571 struct ad7877 *ts = dev_get_drvdata(dev);
572
573 return sprintf(buf, "%u\n", ts->gpio4);
574}
575
576static ssize_t ad7877_gpio4_store(struct device *dev,
577 struct device_attribute *attr,
578 const char *buf, size_t count)
579{
580 struct ad7877 *ts = dev_get_drvdata(dev);
581 unsigned int val;
582 int error;
583
584 error = kstrtouint(buf, 10, &val);
585 if (error)
586 return error;
587
588 mutex_lock(&ts->mutex);
589 ts->gpio4 = !!val;
590 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
591 (ts->gpio4 << 4) | (ts->gpio3 << 5));
592 mutex_unlock(&ts->mutex);
593
594 return count;
595}
596
597static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
598
599static struct attribute *ad7877_attributes[] = {
600 &dev_attr_temp1.attr,
601 &dev_attr_temp2.attr,
602 &dev_attr_aux1.attr,
603 &dev_attr_aux2.attr,
604 &dev_attr_aux3.attr,
605 &dev_attr_bat1.attr,
606 &dev_attr_bat2.attr,
607 &dev_attr_disable.attr,
608 &dev_attr_dac.attr,
609 &dev_attr_gpio3.attr,
610 &dev_attr_gpio4.attr,
611 NULL
612};
613
614static umode_t ad7877_attr_is_visible(struct kobject *kobj,
615 struct attribute *attr, int n)
616{
617 umode_t mode = attr->mode;
618
619 if (attr == &dev_attr_aux3.attr) {
620 if (gpio3)
621 mode = 0;
622 } else if (attr == &dev_attr_gpio3.attr) {
623 if (!gpio3)
624 mode = 0;
625 }
626
627 return mode;
628}
629
630static const struct attribute_group ad7877_attr_group = {
631 .is_visible = ad7877_attr_is_visible,
632 .attrs = ad7877_attributes,
633};
634
635static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
636{
637 struct spi_message *m;
638 int i;
639
640 ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
641 AD7877_POL(ts->stopacq_polarity) |
642 AD7877_AVG(ts->averaging) | AD7877_PM(1) |
643 AD7877_TMR(ts->pen_down_acc_interval) |
644 AD7877_ACQ(ts->acquisition_time) |
645 AD7877_FCD(ts->first_conversion_delay);
646
647 ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
648
649 ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
650 AD7877_READADD(AD7877_REG_XPLUS-1) |
651 AD7877_MODE_SEQ1 | AD7877_DFR;
652
653 ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
654
655 ts->cmd_dummy = 0;
656
657 m = &ts->msg;
658
659 spi_message_init(m);
660
661 m->context = ts;
662
663 ts->xfer[0].tx_buf = &ts->cmd_crtl1;
664 ts->xfer[0].len = 2;
665 ts->xfer[0].cs_change = 1;
666
667 spi_message_add_tail(&ts->xfer[0], m);
668
669 ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
670 ts->xfer[1].len = 2;
671 ts->xfer[1].cs_change = 1;
672
673 spi_message_add_tail(&ts->xfer[1], m);
674
675 for (i = 0; i < AD7877_NR_SENSE; i++) {
676 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
677 ts->xfer[i + 2].len = 2;
678 if (i < (AD7877_NR_SENSE - 1))
679 ts->xfer[i + 2].cs_change = 1;
680 spi_message_add_tail(&ts->xfer[i + 2], m);
681 }
682}
683
684static int ad7877_probe(struct spi_device *spi)
685{
686 struct ad7877 *ts;
687 struct input_dev *input_dev;
688 struct ad7877_platform_data *pdata = dev_get_platdata(&spi->dev);
689 int err;
690 u16 verify;
691
692 if (!spi->irq) {
693 dev_dbg(&spi->dev, "no IRQ?\n");
694 return -ENODEV;
695 }
696
697 if (!pdata) {
698 dev_dbg(&spi->dev, "no platform data?\n");
699 return -ENODEV;
700 }
701
702 /* don't exceed max specified SPI CLK frequency */
703 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
704 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
705 return -EINVAL;
706 }
707
708 spi->bits_per_word = 16;
709 err = spi_setup(spi);
710 if (err) {
711 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
712 return err;
713 }
714
715 ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
716 input_dev = input_allocate_device();
717 if (!ts || !input_dev) {
718 err = -ENOMEM;
719 goto err_free_mem;
720 }
721
722 spi_set_drvdata(spi, ts);
723 ts->spi = spi;
724 ts->input = input_dev;
725
726 setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts);
727 mutex_init(&ts->mutex);
728 spin_lock_init(&ts->lock);
729
730 ts->model = pdata->model ? : 7877;
731 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
732 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
733 ts->pressure_max = pdata->pressure_max ? : ~0;
734
735 ts->stopacq_polarity = pdata->stopacq_polarity;
736 ts->first_conversion_delay = pdata->first_conversion_delay;
737 ts->acquisition_time = pdata->acquisition_time;
738 ts->averaging = pdata->averaging;
739 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
740
741 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
742
743 input_dev->name = "AD7877 Touchscreen";
744 input_dev->phys = ts->phys;
745 input_dev->dev.parent = &spi->dev;
746
747 __set_bit(EV_KEY, input_dev->evbit);
748 __set_bit(BTN_TOUCH, input_dev->keybit);
749 __set_bit(EV_ABS, input_dev->evbit);
750 __set_bit(ABS_X, input_dev->absbit);
751 __set_bit(ABS_Y, input_dev->absbit);
752 __set_bit(ABS_PRESSURE, input_dev->absbit);
753
754 input_set_abs_params(input_dev, ABS_X,
755 pdata->x_min ? : 0,
756 pdata->x_max ? : MAX_12BIT,
757 0, 0);
758 input_set_abs_params(input_dev, ABS_Y,
759 pdata->y_min ? : 0,
760 pdata->y_max ? : MAX_12BIT,
761 0, 0);
762 input_set_abs_params(input_dev, ABS_PRESSURE,
763 pdata->pressure_min, pdata->pressure_max, 0, 0);
764
765 ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
766
767 verify = ad7877_read(spi, AD7877_REG_SEQ1);
768
769 if (verify != AD7877_MM_SEQUENCE){
770 dev_err(&spi->dev, "%s: Failed to probe %s\n",
771 dev_name(&spi->dev), input_dev->name);
772 err = -ENODEV;
773 goto err_free_mem;
774 }
775
776 if (gpio3)
777 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
778
779 ad7877_setup_ts_def_msg(spi, ts);
780
781 /* Request AD7877 /DAV GPIO interrupt */
782
783 err = request_threaded_irq(spi->irq, NULL, ad7877_irq,
784 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
785 spi->dev.driver->name, ts);
786 if (err) {
787 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
788 goto err_free_mem;
789 }
790
791 err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group);
792 if (err)
793 goto err_free_irq;
794
795 err = input_register_device(input_dev);
796 if (err)
797 goto err_remove_attr_group;
798
799 return 0;
800
801err_remove_attr_group:
802 sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
803err_free_irq:
804 free_irq(spi->irq, ts);
805err_free_mem:
806 input_free_device(input_dev);
807 kfree(ts);
808 return err;
809}
810
811static int ad7877_remove(struct spi_device *spi)
812{
813 struct ad7877 *ts = spi_get_drvdata(spi);
814
815 sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
816
817 ad7877_disable(ts);
818 free_irq(ts->spi->irq, ts);
819
820 input_unregister_device(ts->input);
821 kfree(ts);
822
823 dev_dbg(&spi->dev, "unregistered touchscreen\n");
824
825 return 0;
826}
827
828#ifdef CONFIG_PM_SLEEP
829static int ad7877_suspend(struct device *dev)
830{
831 struct ad7877 *ts = dev_get_drvdata(dev);
832
833 ad7877_disable(ts);
834
835 return 0;
836}
837
838static int ad7877_resume(struct device *dev)
839{
840 struct ad7877 *ts = dev_get_drvdata(dev);
841
842 ad7877_enable(ts);
843
844 return 0;
845}
846#endif
847
848static SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume);
849
850static struct spi_driver ad7877_driver = {
851 .driver = {
852 .name = "ad7877",
853 .owner = THIS_MODULE,
854 .pm = &ad7877_pm,
855 },
856 .probe = ad7877_probe,
857 .remove = ad7877_remove,
858};
859
860module_spi_driver(ad7877_driver);
861
862MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
863MODULE_DESCRIPTION("AD7877 touchscreen Driver");
864MODULE_LICENSE("GPL");
865MODULE_ALIAS("spi:ad7877");
1/*
2 * Copyright (C) 2006-2008 Michael Hennerich, Analog Devices Inc.
3 *
4 * Description: AD7877 based touchscreen, sensor (ADCs), DAC and GPIO driver
5 * Based on: ads7846.c
6 *
7 * Bugs: Enter bugs at http://blackfin.uclinux.org/
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, see the file COPYING, or write
21 * to the Free Software Foundation, Inc.,
22 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 *
24 * History:
25 * Copyright (c) 2005 David Brownell
26 * Copyright (c) 2006 Nokia Corporation
27 * Various changes: Imre Deak <imre.deak@nokia.com>
28 *
29 * Using code from:
30 * - corgi_ts.c
31 * Copyright (C) 2004-2005 Richard Purdie
32 * - omap_ts.[hc], ads7846.h, ts_osk.c
33 * Copyright (C) 2002 MontaVista Software
34 * Copyright (C) 2004 Texas Instruments
35 * Copyright (C) 2005 Dirk Behme
36 */
37
38
39#include <linux/device.h>
40#include <linux/delay.h>
41#include <linux/input.h>
42#include <linux/interrupt.h>
43#include <linux/pm.h>
44#include <linux/slab.h>
45#include <linux/spi/spi.h>
46#include <linux/spi/ad7877.h>
47#include <linux/module.h>
48#include <asm/irq.h>
49
50#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(100)
51
52#define MAX_SPI_FREQ_HZ 20000000
53#define MAX_12BIT ((1<<12)-1)
54
55#define AD7877_REG_ZEROS 0
56#define AD7877_REG_CTRL1 1
57#define AD7877_REG_CTRL2 2
58#define AD7877_REG_ALERT 3
59#define AD7877_REG_AUX1HIGH 4
60#define AD7877_REG_AUX1LOW 5
61#define AD7877_REG_BAT1HIGH 6
62#define AD7877_REG_BAT1LOW 7
63#define AD7877_REG_BAT2HIGH 8
64#define AD7877_REG_BAT2LOW 9
65#define AD7877_REG_TEMP1HIGH 10
66#define AD7877_REG_TEMP1LOW 11
67#define AD7877_REG_SEQ0 12
68#define AD7877_REG_SEQ1 13
69#define AD7877_REG_DAC 14
70#define AD7877_REG_NONE1 15
71#define AD7877_REG_EXTWRITE 15
72#define AD7877_REG_XPLUS 16
73#define AD7877_REG_YPLUS 17
74#define AD7877_REG_Z2 18
75#define AD7877_REG_aux1 19
76#define AD7877_REG_aux2 20
77#define AD7877_REG_aux3 21
78#define AD7877_REG_bat1 22
79#define AD7877_REG_bat2 23
80#define AD7877_REG_temp1 24
81#define AD7877_REG_temp2 25
82#define AD7877_REG_Z1 26
83#define AD7877_REG_GPIOCTRL1 27
84#define AD7877_REG_GPIOCTRL2 28
85#define AD7877_REG_GPIODATA 29
86#define AD7877_REG_NONE2 30
87#define AD7877_REG_NONE3 31
88
89#define AD7877_SEQ_YPLUS_BIT (1<<11)
90#define AD7877_SEQ_XPLUS_BIT (1<<10)
91#define AD7877_SEQ_Z2_BIT (1<<9)
92#define AD7877_SEQ_AUX1_BIT (1<<8)
93#define AD7877_SEQ_AUX2_BIT (1<<7)
94#define AD7877_SEQ_AUX3_BIT (1<<6)
95#define AD7877_SEQ_BAT1_BIT (1<<5)
96#define AD7877_SEQ_BAT2_BIT (1<<4)
97#define AD7877_SEQ_TEMP1_BIT (1<<3)
98#define AD7877_SEQ_TEMP2_BIT (1<<2)
99#define AD7877_SEQ_Z1_BIT (1<<1)
100
101enum {
102 AD7877_SEQ_YPOS = 0,
103 AD7877_SEQ_XPOS = 1,
104 AD7877_SEQ_Z2 = 2,
105 AD7877_SEQ_AUX1 = 3,
106 AD7877_SEQ_AUX2 = 4,
107 AD7877_SEQ_AUX3 = 5,
108 AD7877_SEQ_BAT1 = 6,
109 AD7877_SEQ_BAT2 = 7,
110 AD7877_SEQ_TEMP1 = 8,
111 AD7877_SEQ_TEMP2 = 9,
112 AD7877_SEQ_Z1 = 10,
113 AD7877_NR_SENSE = 11,
114};
115
116/* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */
117#define AD7877_DAC_CONF 0x1
118
119/* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */
120#define AD7877_EXTW_GPIO_3_CONF 0x1C4
121#define AD7877_EXTW_GPIO_DATA 0x200
122
123/* Control REG 2 */
124#define AD7877_TMR(x) ((x & 0x3) << 0)
125#define AD7877_REF(x) ((x & 0x1) << 2)
126#define AD7877_POL(x) ((x & 0x1) << 3)
127#define AD7877_FCD(x) ((x & 0x3) << 4)
128#define AD7877_PM(x) ((x & 0x3) << 6)
129#define AD7877_ACQ(x) ((x & 0x3) << 8)
130#define AD7877_AVG(x) ((x & 0x3) << 10)
131
132/* Control REG 1 */
133#define AD7877_SER (1 << 11) /* non-differential */
134#define AD7877_DFR (0 << 11) /* differential */
135
136#define AD7877_MODE_NOC (0) /* Do not convert */
137#define AD7877_MODE_SCC (1) /* Single channel conversion */
138#define AD7877_MODE_SEQ0 (2) /* Sequence 0 in Slave Mode */
139#define AD7877_MODE_SEQ1 (3) /* Sequence 1 in Master Mode */
140
141#define AD7877_CHANADD(x) ((x&0xF)<<7)
142#define AD7877_READADD(x) ((x)<<2)
143#define AD7877_WRITEADD(x) ((x)<<12)
144
145#define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \
146 AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \
147 AD7877_READADD(AD7877_REG_ ## x))
148
149#define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \
150 AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT)
151
152/*
153 * Non-touchscreen sensors only use single-ended conversions.
154 */
155
156struct ser_req {
157 u16 reset;
158 u16 ref_on;
159 u16 command;
160 struct spi_message msg;
161 struct spi_transfer xfer[6];
162
163 /*
164 * DMA (thus cache coherency maintenance) requires the
165 * transfer buffers to live in their own cache lines.
166 */
167 u16 sample ____cacheline_aligned;
168};
169
170struct ad7877 {
171 struct input_dev *input;
172 char phys[32];
173
174 struct spi_device *spi;
175 u16 model;
176 u16 vref_delay_usecs;
177 u16 x_plate_ohms;
178 u16 pressure_max;
179
180 u16 cmd_crtl1;
181 u16 cmd_crtl2;
182 u16 cmd_dummy;
183 u16 dac;
184
185 u8 stopacq_polarity;
186 u8 first_conversion_delay;
187 u8 acquisition_time;
188 u8 averaging;
189 u8 pen_down_acc_interval;
190
191 struct spi_transfer xfer[AD7877_NR_SENSE + 2];
192 struct spi_message msg;
193
194 struct mutex mutex;
195 bool disabled; /* P: mutex */
196 bool gpio3; /* P: mutex */
197 bool gpio4; /* P: mutex */
198
199 spinlock_t lock;
200 struct timer_list timer; /* P: lock */
201
202 /*
203 * DMA (thus cache coherency maintenance) requires the
204 * transfer buffers to live in their own cache lines.
205 */
206 u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned;
207};
208
209static bool gpio3;
210module_param(gpio3, bool, 0);
211MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
212
213static int ad7877_read(struct spi_device *spi, u16 reg)
214{
215 struct ser_req *req;
216 int status, ret;
217
218 req = kzalloc(sizeof *req, GFP_KERNEL);
219 if (!req)
220 return -ENOMEM;
221
222 spi_message_init(&req->msg);
223
224 req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) |
225 AD7877_READADD(reg));
226 req->xfer[0].tx_buf = &req->command;
227 req->xfer[0].len = 2;
228 req->xfer[0].cs_change = 1;
229
230 req->xfer[1].rx_buf = &req->sample;
231 req->xfer[1].len = 2;
232
233 spi_message_add_tail(&req->xfer[0], &req->msg);
234 spi_message_add_tail(&req->xfer[1], &req->msg);
235
236 status = spi_sync(spi, &req->msg);
237 ret = status ? : req->sample;
238
239 kfree(req);
240
241 return ret;
242}
243
244static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
245{
246 struct ser_req *req;
247 int status;
248
249 req = kzalloc(sizeof *req, GFP_KERNEL);
250 if (!req)
251 return -ENOMEM;
252
253 spi_message_init(&req->msg);
254
255 req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
256 req->xfer[0].tx_buf = &req->command;
257 req->xfer[0].len = 2;
258
259 spi_message_add_tail(&req->xfer[0], &req->msg);
260
261 status = spi_sync(spi, &req->msg);
262
263 kfree(req);
264
265 return status;
266}
267
268static int ad7877_read_adc(struct spi_device *spi, unsigned command)
269{
270 struct ad7877 *ts = spi_get_drvdata(spi);
271 struct ser_req *req;
272 int status;
273 int sample;
274 int i;
275
276 req = kzalloc(sizeof *req, GFP_KERNEL);
277 if (!req)
278 return -ENOMEM;
279
280 spi_message_init(&req->msg);
281
282 /* activate reference, so it has time to settle; */
283 req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) |
284 AD7877_POL(ts->stopacq_polarity) |
285 AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) |
286 AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0);
287
288 req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
289
290 req->command = (u16) command;
291
292 req->xfer[0].tx_buf = &req->reset;
293 req->xfer[0].len = 2;
294 req->xfer[0].cs_change = 1;
295
296 req->xfer[1].tx_buf = &req->ref_on;
297 req->xfer[1].len = 2;
298 req->xfer[1].delay_usecs = ts->vref_delay_usecs;
299 req->xfer[1].cs_change = 1;
300
301 req->xfer[2].tx_buf = &req->command;
302 req->xfer[2].len = 2;
303 req->xfer[2].delay_usecs = ts->vref_delay_usecs;
304 req->xfer[2].cs_change = 1;
305
306 req->xfer[3].rx_buf = &req->sample;
307 req->xfer[3].len = 2;
308 req->xfer[3].cs_change = 1;
309
310 req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/
311 req->xfer[4].len = 2;
312 req->xfer[4].cs_change = 1;
313
314 req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/
315 req->xfer[5].len = 2;
316
317 /* group all the transfers together, so we can't interfere with
318 * reading touchscreen state; disable penirq while sampling
319 */
320 for (i = 0; i < 6; i++)
321 spi_message_add_tail(&req->xfer[i], &req->msg);
322
323 status = spi_sync(spi, &req->msg);
324 sample = req->sample;
325
326 kfree(req);
327
328 return status ? : sample;
329}
330
331static int ad7877_process_data(struct ad7877 *ts)
332{
333 struct input_dev *input_dev = ts->input;
334 unsigned Rt;
335 u16 x, y, z1, z2;
336
337 x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
338 y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
339 z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
340 z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
341
342 /*
343 * The samples processed here are already preprocessed by the AD7877.
344 * The preprocessing function consists of an averaging filter.
345 * The combination of 'first conversion delay' and averaging provides a robust solution,
346 * discarding the spurious noise in the signal and keeping only the data of interest.
347 * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h)
348 * Other user-programmable conversion controls include variable acquisition time,
349 * and first conversion delay. Up to 16 averages can be taken per conversion.
350 */
351
352 if (likely(x && z1)) {
353 /* compute touch pressure resistance using equation #1 */
354 Rt = (z2 - z1) * x * ts->x_plate_ohms;
355 Rt /= z1;
356 Rt = (Rt + 2047) >> 12;
357
358 /*
359 * Sample found inconsistent, pressure is beyond
360 * the maximum. Don't report it to user space.
361 */
362 if (Rt > ts->pressure_max)
363 return -EINVAL;
364
365 if (!timer_pending(&ts->timer))
366 input_report_key(input_dev, BTN_TOUCH, 1);
367
368 input_report_abs(input_dev, ABS_X, x);
369 input_report_abs(input_dev, ABS_Y, y);
370 input_report_abs(input_dev, ABS_PRESSURE, Rt);
371 input_sync(input_dev);
372
373 return 0;
374 }
375
376 return -EINVAL;
377}
378
379static inline void ad7877_ts_event_release(struct ad7877 *ts)
380{
381 struct input_dev *input_dev = ts->input;
382
383 input_report_abs(input_dev, ABS_PRESSURE, 0);
384 input_report_key(input_dev, BTN_TOUCH, 0);
385 input_sync(input_dev);
386}
387
388static void ad7877_timer(struct timer_list *t)
389{
390 struct ad7877 *ts = from_timer(ts, t, timer);
391 unsigned long flags;
392
393 spin_lock_irqsave(&ts->lock, flags);
394 ad7877_ts_event_release(ts);
395 spin_unlock_irqrestore(&ts->lock, flags);
396}
397
398static irqreturn_t ad7877_irq(int irq, void *handle)
399{
400 struct ad7877 *ts = handle;
401 unsigned long flags;
402 int error;
403
404 error = spi_sync(ts->spi, &ts->msg);
405 if (error) {
406 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
407 goto out;
408 }
409
410 spin_lock_irqsave(&ts->lock, flags);
411 error = ad7877_process_data(ts);
412 if (!error)
413 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
414 spin_unlock_irqrestore(&ts->lock, flags);
415
416out:
417 return IRQ_HANDLED;
418}
419
420static void ad7877_disable(void *data)
421{
422 struct ad7877 *ts = data;
423
424 mutex_lock(&ts->mutex);
425
426 if (!ts->disabled) {
427 ts->disabled = true;
428 disable_irq(ts->spi->irq);
429
430 if (del_timer_sync(&ts->timer))
431 ad7877_ts_event_release(ts);
432 }
433
434 /*
435 * We know the chip's in lowpower mode since we always
436 * leave it that way after every request
437 */
438
439 mutex_unlock(&ts->mutex);
440}
441
442static void ad7877_enable(struct ad7877 *ts)
443{
444 mutex_lock(&ts->mutex);
445
446 if (ts->disabled) {
447 ts->disabled = false;
448 enable_irq(ts->spi->irq);
449 }
450
451 mutex_unlock(&ts->mutex);
452}
453
454#define SHOW(name) static ssize_t \
455name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
456{ \
457 struct ad7877 *ts = dev_get_drvdata(dev); \
458 ssize_t v = ad7877_read_adc(ts->spi, \
459 AD7877_READ_CHAN(name)); \
460 if (v < 0) \
461 return v; \
462 return sprintf(buf, "%u\n", (unsigned) v); \
463} \
464static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
465
466SHOW(aux1)
467SHOW(aux2)
468SHOW(aux3)
469SHOW(bat1)
470SHOW(bat2)
471SHOW(temp1)
472SHOW(temp2)
473
474static ssize_t ad7877_disable_show(struct device *dev,
475 struct device_attribute *attr, char *buf)
476{
477 struct ad7877 *ts = dev_get_drvdata(dev);
478
479 return sprintf(buf, "%u\n", ts->disabled);
480}
481
482static ssize_t ad7877_disable_store(struct device *dev,
483 struct device_attribute *attr,
484 const char *buf, size_t count)
485{
486 struct ad7877 *ts = dev_get_drvdata(dev);
487 unsigned int val;
488 int error;
489
490 error = kstrtouint(buf, 10, &val);
491 if (error)
492 return error;
493
494 if (val)
495 ad7877_disable(ts);
496 else
497 ad7877_enable(ts);
498
499 return count;
500}
501
502static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
503
504static ssize_t ad7877_dac_show(struct device *dev,
505 struct device_attribute *attr, char *buf)
506{
507 struct ad7877 *ts = dev_get_drvdata(dev);
508
509 return sprintf(buf, "%u\n", ts->dac);
510}
511
512static ssize_t ad7877_dac_store(struct device *dev,
513 struct device_attribute *attr,
514 const char *buf, size_t count)
515{
516 struct ad7877 *ts = dev_get_drvdata(dev);
517 unsigned int val;
518 int error;
519
520 error = kstrtouint(buf, 10, &val);
521 if (error)
522 return error;
523
524 mutex_lock(&ts->mutex);
525 ts->dac = val & 0xFF;
526 ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
527 mutex_unlock(&ts->mutex);
528
529 return count;
530}
531
532static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
533
534static ssize_t ad7877_gpio3_show(struct device *dev,
535 struct device_attribute *attr, char *buf)
536{
537 struct ad7877 *ts = dev_get_drvdata(dev);
538
539 return sprintf(buf, "%u\n", ts->gpio3);
540}
541
542static ssize_t ad7877_gpio3_store(struct device *dev,
543 struct device_attribute *attr,
544 const char *buf, size_t count)
545{
546 struct ad7877 *ts = dev_get_drvdata(dev);
547 unsigned int val;
548 int error;
549
550 error = kstrtouint(buf, 10, &val);
551 if (error)
552 return error;
553
554 mutex_lock(&ts->mutex);
555 ts->gpio3 = !!val;
556 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
557 (ts->gpio4 << 4) | (ts->gpio3 << 5));
558 mutex_unlock(&ts->mutex);
559
560 return count;
561}
562
563static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
564
565static ssize_t ad7877_gpio4_show(struct device *dev,
566 struct device_attribute *attr, char *buf)
567{
568 struct ad7877 *ts = dev_get_drvdata(dev);
569
570 return sprintf(buf, "%u\n", ts->gpio4);
571}
572
573static ssize_t ad7877_gpio4_store(struct device *dev,
574 struct device_attribute *attr,
575 const char *buf, size_t count)
576{
577 struct ad7877 *ts = dev_get_drvdata(dev);
578 unsigned int val;
579 int error;
580
581 error = kstrtouint(buf, 10, &val);
582 if (error)
583 return error;
584
585 mutex_lock(&ts->mutex);
586 ts->gpio4 = !!val;
587 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
588 (ts->gpio4 << 4) | (ts->gpio3 << 5));
589 mutex_unlock(&ts->mutex);
590
591 return count;
592}
593
594static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
595
596static struct attribute *ad7877_attributes[] = {
597 &dev_attr_temp1.attr,
598 &dev_attr_temp2.attr,
599 &dev_attr_aux1.attr,
600 &dev_attr_aux2.attr,
601 &dev_attr_aux3.attr,
602 &dev_attr_bat1.attr,
603 &dev_attr_bat2.attr,
604 &dev_attr_disable.attr,
605 &dev_attr_dac.attr,
606 &dev_attr_gpio3.attr,
607 &dev_attr_gpio4.attr,
608 NULL
609};
610
611static umode_t ad7877_attr_is_visible(struct kobject *kobj,
612 struct attribute *attr, int n)
613{
614 umode_t mode = attr->mode;
615
616 if (attr == &dev_attr_aux3.attr) {
617 if (gpio3)
618 mode = 0;
619 } else if (attr == &dev_attr_gpio3.attr) {
620 if (!gpio3)
621 mode = 0;
622 }
623
624 return mode;
625}
626
627static const struct attribute_group ad7877_attr_group = {
628 .is_visible = ad7877_attr_is_visible,
629 .attrs = ad7877_attributes,
630};
631
632static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
633{
634 struct spi_message *m;
635 int i;
636
637 ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
638 AD7877_POL(ts->stopacq_polarity) |
639 AD7877_AVG(ts->averaging) | AD7877_PM(1) |
640 AD7877_TMR(ts->pen_down_acc_interval) |
641 AD7877_ACQ(ts->acquisition_time) |
642 AD7877_FCD(ts->first_conversion_delay);
643
644 ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
645
646 ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
647 AD7877_READADD(AD7877_REG_XPLUS-1) |
648 AD7877_MODE_SEQ1 | AD7877_DFR;
649
650 ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
651
652 ts->cmd_dummy = 0;
653
654 m = &ts->msg;
655
656 spi_message_init(m);
657
658 m->context = ts;
659
660 ts->xfer[0].tx_buf = &ts->cmd_crtl1;
661 ts->xfer[0].len = 2;
662 ts->xfer[0].cs_change = 1;
663
664 spi_message_add_tail(&ts->xfer[0], m);
665
666 ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
667 ts->xfer[1].len = 2;
668 ts->xfer[1].cs_change = 1;
669
670 spi_message_add_tail(&ts->xfer[1], m);
671
672 for (i = 0; i < AD7877_NR_SENSE; i++) {
673 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
674 ts->xfer[i + 2].len = 2;
675 if (i < (AD7877_NR_SENSE - 1))
676 ts->xfer[i + 2].cs_change = 1;
677 spi_message_add_tail(&ts->xfer[i + 2], m);
678 }
679}
680
681static int ad7877_probe(struct spi_device *spi)
682{
683 struct ad7877 *ts;
684 struct input_dev *input_dev;
685 struct ad7877_platform_data *pdata = dev_get_platdata(&spi->dev);
686 int err;
687 u16 verify;
688
689 if (!spi->irq) {
690 dev_dbg(&spi->dev, "no IRQ?\n");
691 return -ENODEV;
692 }
693
694 if (!pdata) {
695 dev_dbg(&spi->dev, "no platform data?\n");
696 return -ENODEV;
697 }
698
699 /* don't exceed max specified SPI CLK frequency */
700 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
701 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
702 return -EINVAL;
703 }
704
705 spi->bits_per_word = 16;
706 err = spi_setup(spi);
707 if (err) {
708 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
709 return err;
710 }
711
712 ts = devm_kzalloc(&spi->dev, sizeof(struct ad7877), GFP_KERNEL);
713 if (!ts)
714 return -ENOMEM;
715
716 input_dev = devm_input_allocate_device(&spi->dev);
717 if (!input_dev)
718 return -ENOMEM;
719
720 err = devm_add_action_or_reset(&spi->dev, ad7877_disable, ts);
721 if (err)
722 return err;
723
724 spi_set_drvdata(spi, ts);
725 ts->spi = spi;
726 ts->input = input_dev;
727
728 timer_setup(&ts->timer, ad7877_timer, 0);
729 mutex_init(&ts->mutex);
730 spin_lock_init(&ts->lock);
731
732 ts->model = pdata->model ? : 7877;
733 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
734 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
735 ts->pressure_max = pdata->pressure_max ? : ~0;
736
737 ts->stopacq_polarity = pdata->stopacq_polarity;
738 ts->first_conversion_delay = pdata->first_conversion_delay;
739 ts->acquisition_time = pdata->acquisition_time;
740 ts->averaging = pdata->averaging;
741 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
742
743 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
744
745 input_dev->name = "AD7877 Touchscreen";
746 input_dev->phys = ts->phys;
747 input_dev->dev.parent = &spi->dev;
748
749 __set_bit(EV_KEY, input_dev->evbit);
750 __set_bit(BTN_TOUCH, input_dev->keybit);
751 __set_bit(EV_ABS, input_dev->evbit);
752 __set_bit(ABS_X, input_dev->absbit);
753 __set_bit(ABS_Y, input_dev->absbit);
754 __set_bit(ABS_PRESSURE, input_dev->absbit);
755
756 input_set_abs_params(input_dev, ABS_X,
757 pdata->x_min ? : 0,
758 pdata->x_max ? : MAX_12BIT,
759 0, 0);
760 input_set_abs_params(input_dev, ABS_Y,
761 pdata->y_min ? : 0,
762 pdata->y_max ? : MAX_12BIT,
763 0, 0);
764 input_set_abs_params(input_dev, ABS_PRESSURE,
765 pdata->pressure_min, pdata->pressure_max, 0, 0);
766
767 ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
768
769 verify = ad7877_read(spi, AD7877_REG_SEQ1);
770
771 if (verify != AD7877_MM_SEQUENCE) {
772 dev_err(&spi->dev, "%s: Failed to probe %s\n",
773 dev_name(&spi->dev), input_dev->name);
774 return -ENODEV;
775 }
776
777 if (gpio3)
778 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
779
780 ad7877_setup_ts_def_msg(spi, ts);
781
782 /* Request AD7877 /DAV GPIO interrupt */
783
784 err = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, ad7877_irq,
785 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
786 spi->dev.driver->name, ts);
787 if (err) {
788 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
789 return err;
790 }
791
792 err = devm_device_add_group(&spi->dev, &ad7877_attr_group);
793 if (err)
794 return err;
795
796 err = input_register_device(input_dev);
797 if (err)
798 return err;
799
800 return 0;
801}
802
803static int __maybe_unused ad7877_suspend(struct device *dev)
804{
805 struct ad7877 *ts = dev_get_drvdata(dev);
806
807 ad7877_disable(ts);
808
809 return 0;
810}
811
812static int __maybe_unused ad7877_resume(struct device *dev)
813{
814 struct ad7877 *ts = dev_get_drvdata(dev);
815
816 ad7877_enable(ts);
817
818 return 0;
819}
820
821static SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume);
822
823static struct spi_driver ad7877_driver = {
824 .driver = {
825 .name = "ad7877",
826 .pm = &ad7877_pm,
827 },
828 .probe = ad7877_probe,
829};
830
831module_spi_driver(ad7877_driver);
832
833MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
834MODULE_DESCRIPTION("AD7877 touchscreen Driver");
835MODULE_LICENSE("GPL");
836MODULE_ALIAS("spi:ad7877");