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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2006-2008 Michael Hennerich, Analog Devices Inc.
4 *
5 * Description: AD7877 based touchscreen, sensor (ADCs), DAC and GPIO driver
6 * Based on: ads7846.c
7 *
8 * Bugs: Enter bugs at http://blackfin.uclinux.org/
9 *
10 * History:
11 * Copyright (c) 2005 David Brownell
12 * Copyright (c) 2006 Nokia Corporation
13 * Various changes: Imre Deak <imre.deak@nokia.com>
14 *
15 * Using code from:
16 * - corgi_ts.c
17 * Copyright (C) 2004-2005 Richard Purdie
18 * - omap_ts.[hc], ads7846.h, ts_osk.c
19 * Copyright (C) 2002 MontaVista Software
20 * Copyright (C) 2004 Texas Instruments
21 * Copyright (C) 2005 Dirk Behme
22 */
23
24
25#include <linux/device.h>
26#include <linux/delay.h>
27#include <linux/input.h>
28#include <linux/interrupt.h>
29#include <linux/pm.h>
30#include <linux/slab.h>
31#include <linux/spi/spi.h>
32#include <linux/spi/ad7877.h>
33#include <linux/module.h>
34#include <asm/irq.h>
35
36#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(100)
37
38#define MAX_SPI_FREQ_HZ 20000000
39#define MAX_12BIT ((1<<12)-1)
40
41#define AD7877_REG_ZEROS 0
42#define AD7877_REG_CTRL1 1
43#define AD7877_REG_CTRL2 2
44#define AD7877_REG_ALERT 3
45#define AD7877_REG_AUX1HIGH 4
46#define AD7877_REG_AUX1LOW 5
47#define AD7877_REG_BAT1HIGH 6
48#define AD7877_REG_BAT1LOW 7
49#define AD7877_REG_BAT2HIGH 8
50#define AD7877_REG_BAT2LOW 9
51#define AD7877_REG_TEMP1HIGH 10
52#define AD7877_REG_TEMP1LOW 11
53#define AD7877_REG_SEQ0 12
54#define AD7877_REG_SEQ1 13
55#define AD7877_REG_DAC 14
56#define AD7877_REG_NONE1 15
57#define AD7877_REG_EXTWRITE 15
58#define AD7877_REG_XPLUS 16
59#define AD7877_REG_YPLUS 17
60#define AD7877_REG_Z2 18
61#define AD7877_REG_aux1 19
62#define AD7877_REG_aux2 20
63#define AD7877_REG_aux3 21
64#define AD7877_REG_bat1 22
65#define AD7877_REG_bat2 23
66#define AD7877_REG_temp1 24
67#define AD7877_REG_temp2 25
68#define AD7877_REG_Z1 26
69#define AD7877_REG_GPIOCTRL1 27
70#define AD7877_REG_GPIOCTRL2 28
71#define AD7877_REG_GPIODATA 29
72#define AD7877_REG_NONE2 30
73#define AD7877_REG_NONE3 31
74
75#define AD7877_SEQ_YPLUS_BIT (1<<11)
76#define AD7877_SEQ_XPLUS_BIT (1<<10)
77#define AD7877_SEQ_Z2_BIT (1<<9)
78#define AD7877_SEQ_AUX1_BIT (1<<8)
79#define AD7877_SEQ_AUX2_BIT (1<<7)
80#define AD7877_SEQ_AUX3_BIT (1<<6)
81#define AD7877_SEQ_BAT1_BIT (1<<5)
82#define AD7877_SEQ_BAT2_BIT (1<<4)
83#define AD7877_SEQ_TEMP1_BIT (1<<3)
84#define AD7877_SEQ_TEMP2_BIT (1<<2)
85#define AD7877_SEQ_Z1_BIT (1<<1)
86
87enum {
88 AD7877_SEQ_YPOS = 0,
89 AD7877_SEQ_XPOS = 1,
90 AD7877_SEQ_Z2 = 2,
91 AD7877_SEQ_AUX1 = 3,
92 AD7877_SEQ_AUX2 = 4,
93 AD7877_SEQ_AUX3 = 5,
94 AD7877_SEQ_BAT1 = 6,
95 AD7877_SEQ_BAT2 = 7,
96 AD7877_SEQ_TEMP1 = 8,
97 AD7877_SEQ_TEMP2 = 9,
98 AD7877_SEQ_Z1 = 10,
99 AD7877_NR_SENSE = 11,
100};
101
102/* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */
103#define AD7877_DAC_CONF 0x1
104
105/* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */
106#define AD7877_EXTW_GPIO_3_CONF 0x1C4
107#define AD7877_EXTW_GPIO_DATA 0x200
108
109/* Control REG 2 */
110#define AD7877_TMR(x) ((x & 0x3) << 0)
111#define AD7877_REF(x) ((x & 0x1) << 2)
112#define AD7877_POL(x) ((x & 0x1) << 3)
113#define AD7877_FCD(x) ((x & 0x3) << 4)
114#define AD7877_PM(x) ((x & 0x3) << 6)
115#define AD7877_ACQ(x) ((x & 0x3) << 8)
116#define AD7877_AVG(x) ((x & 0x3) << 10)
117
118/* Control REG 1 */
119#define AD7877_SER (1 << 11) /* non-differential */
120#define AD7877_DFR (0 << 11) /* differential */
121
122#define AD7877_MODE_NOC (0) /* Do not convert */
123#define AD7877_MODE_SCC (1) /* Single channel conversion */
124#define AD7877_MODE_SEQ0 (2) /* Sequence 0 in Slave Mode */
125#define AD7877_MODE_SEQ1 (3) /* Sequence 1 in Master Mode */
126
127#define AD7877_CHANADD(x) ((x&0xF)<<7)
128#define AD7877_READADD(x) ((x)<<2)
129#define AD7877_WRITEADD(x) ((x)<<12)
130
131#define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \
132 AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \
133 AD7877_READADD(AD7877_REG_ ## x))
134
135#define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \
136 AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT)
137
138/*
139 * Non-touchscreen sensors only use single-ended conversions.
140 */
141
142struct ser_req {
143 u16 reset;
144 u16 ref_on;
145 u16 command;
146 struct spi_message msg;
147 struct spi_transfer xfer[6];
148
149 /*
150 * DMA (thus cache coherency maintenance) requires the
151 * transfer buffers to live in their own cache lines.
152 */
153 u16 sample ____cacheline_aligned;
154};
155
156struct ad7877 {
157 struct input_dev *input;
158 char phys[32];
159
160 struct spi_device *spi;
161 u16 model;
162 u16 vref_delay_usecs;
163 u16 x_plate_ohms;
164 u16 pressure_max;
165
166 u16 cmd_crtl1;
167 u16 cmd_crtl2;
168 u16 cmd_dummy;
169 u16 dac;
170
171 u8 stopacq_polarity;
172 u8 first_conversion_delay;
173 u8 acquisition_time;
174 u8 averaging;
175 u8 pen_down_acc_interval;
176
177 struct spi_transfer xfer[AD7877_NR_SENSE + 2];
178 struct spi_message msg;
179
180 struct mutex mutex;
181 bool disabled; /* P: mutex */
182 bool gpio3; /* P: mutex */
183 bool gpio4; /* P: mutex */
184
185 spinlock_t lock;
186 struct timer_list timer; /* P: lock */
187
188 /*
189 * DMA (thus cache coherency maintenance) requires the
190 * transfer buffers to live in their own cache lines.
191 */
192 u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned;
193};
194
195static bool gpio3;
196module_param(gpio3, bool, 0);
197MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
198
199static int ad7877_read(struct spi_device *spi, u16 reg)
200{
201 struct ser_req *req;
202 int status, ret;
203
204 req = kzalloc(sizeof *req, GFP_KERNEL);
205 if (!req)
206 return -ENOMEM;
207
208 spi_message_init(&req->msg);
209
210 req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) |
211 AD7877_READADD(reg));
212 req->xfer[0].tx_buf = &req->command;
213 req->xfer[0].len = 2;
214 req->xfer[0].cs_change = 1;
215
216 req->xfer[1].rx_buf = &req->sample;
217 req->xfer[1].len = 2;
218
219 spi_message_add_tail(&req->xfer[0], &req->msg);
220 spi_message_add_tail(&req->xfer[1], &req->msg);
221
222 status = spi_sync(spi, &req->msg);
223 ret = status ? : req->sample;
224
225 kfree(req);
226
227 return ret;
228}
229
230static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
231{
232 struct ser_req *req;
233 int status;
234
235 req = kzalloc(sizeof *req, GFP_KERNEL);
236 if (!req)
237 return -ENOMEM;
238
239 spi_message_init(&req->msg);
240
241 req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
242 req->xfer[0].tx_buf = &req->command;
243 req->xfer[0].len = 2;
244
245 spi_message_add_tail(&req->xfer[0], &req->msg);
246
247 status = spi_sync(spi, &req->msg);
248
249 kfree(req);
250
251 return status;
252}
253
254static int ad7877_read_adc(struct spi_device *spi, unsigned command)
255{
256 struct ad7877 *ts = spi_get_drvdata(spi);
257 struct ser_req *req;
258 int status;
259 int sample;
260 int i;
261
262 req = kzalloc(sizeof *req, GFP_KERNEL);
263 if (!req)
264 return -ENOMEM;
265
266 spi_message_init(&req->msg);
267
268 /* activate reference, so it has time to settle; */
269 req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) |
270 AD7877_POL(ts->stopacq_polarity) |
271 AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) |
272 AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0);
273
274 req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
275
276 req->command = (u16) command;
277
278 req->xfer[0].tx_buf = &req->reset;
279 req->xfer[0].len = 2;
280 req->xfer[0].cs_change = 1;
281
282 req->xfer[1].tx_buf = &req->ref_on;
283 req->xfer[1].len = 2;
284 req->xfer[1].delay.value = ts->vref_delay_usecs;
285 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS;
286 req->xfer[1].cs_change = 1;
287
288 req->xfer[2].tx_buf = &req->command;
289 req->xfer[2].len = 2;
290 req->xfer[2].delay.value = ts->vref_delay_usecs;
291 req->xfer[2].delay.unit = SPI_DELAY_UNIT_USECS;
292 req->xfer[2].cs_change = 1;
293
294 req->xfer[3].rx_buf = &req->sample;
295 req->xfer[3].len = 2;
296 req->xfer[3].cs_change = 1;
297
298 req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/
299 req->xfer[4].len = 2;
300 req->xfer[4].cs_change = 1;
301
302 req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/
303 req->xfer[5].len = 2;
304
305 /* group all the transfers together, so we can't interfere with
306 * reading touchscreen state; disable penirq while sampling
307 */
308 for (i = 0; i < 6; i++)
309 spi_message_add_tail(&req->xfer[i], &req->msg);
310
311 status = spi_sync(spi, &req->msg);
312 sample = req->sample;
313
314 kfree(req);
315
316 return status ? : sample;
317}
318
319static int ad7877_process_data(struct ad7877 *ts)
320{
321 struct input_dev *input_dev = ts->input;
322 unsigned Rt;
323 u16 x, y, z1, z2;
324
325 x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
326 y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
327 z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
328 z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
329
330 /*
331 * The samples processed here are already preprocessed by the AD7877.
332 * The preprocessing function consists of an averaging filter.
333 * The combination of 'first conversion delay' and averaging provides a robust solution,
334 * discarding the spurious noise in the signal and keeping only the data of interest.
335 * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h)
336 * Other user-programmable conversion controls include variable acquisition time,
337 * and first conversion delay. Up to 16 averages can be taken per conversion.
338 */
339
340 if (likely(x && z1)) {
341 /* compute touch pressure resistance using equation #1 */
342 Rt = (z2 - z1) * x * ts->x_plate_ohms;
343 Rt /= z1;
344 Rt = (Rt + 2047) >> 12;
345
346 /*
347 * Sample found inconsistent, pressure is beyond
348 * the maximum. Don't report it to user space.
349 */
350 if (Rt > ts->pressure_max)
351 return -EINVAL;
352
353 if (!timer_pending(&ts->timer))
354 input_report_key(input_dev, BTN_TOUCH, 1);
355
356 input_report_abs(input_dev, ABS_X, x);
357 input_report_abs(input_dev, ABS_Y, y);
358 input_report_abs(input_dev, ABS_PRESSURE, Rt);
359 input_sync(input_dev);
360
361 return 0;
362 }
363
364 return -EINVAL;
365}
366
367static inline void ad7877_ts_event_release(struct ad7877 *ts)
368{
369 struct input_dev *input_dev = ts->input;
370
371 input_report_abs(input_dev, ABS_PRESSURE, 0);
372 input_report_key(input_dev, BTN_TOUCH, 0);
373 input_sync(input_dev);
374}
375
376static void ad7877_timer(struct timer_list *t)
377{
378 struct ad7877 *ts = from_timer(ts, t, timer);
379 unsigned long flags;
380
381 spin_lock_irqsave(&ts->lock, flags);
382 ad7877_ts_event_release(ts);
383 spin_unlock_irqrestore(&ts->lock, flags);
384}
385
386static irqreturn_t ad7877_irq(int irq, void *handle)
387{
388 struct ad7877 *ts = handle;
389 unsigned long flags;
390 int error;
391
392 error = spi_sync(ts->spi, &ts->msg);
393 if (error) {
394 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
395 goto out;
396 }
397
398 spin_lock_irqsave(&ts->lock, flags);
399 error = ad7877_process_data(ts);
400 if (!error)
401 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
402 spin_unlock_irqrestore(&ts->lock, flags);
403
404out:
405 return IRQ_HANDLED;
406}
407
408static void ad7877_disable(void *data)
409{
410 struct ad7877 *ts = data;
411
412 mutex_lock(&ts->mutex);
413
414 if (!ts->disabled) {
415 ts->disabled = true;
416 disable_irq(ts->spi->irq);
417
418 if (del_timer_sync(&ts->timer))
419 ad7877_ts_event_release(ts);
420 }
421
422 /*
423 * We know the chip's in lowpower mode since we always
424 * leave it that way after every request
425 */
426
427 mutex_unlock(&ts->mutex);
428}
429
430static void ad7877_enable(struct ad7877 *ts)
431{
432 mutex_lock(&ts->mutex);
433
434 if (ts->disabled) {
435 ts->disabled = false;
436 enable_irq(ts->spi->irq);
437 }
438
439 mutex_unlock(&ts->mutex);
440}
441
442#define SHOW(name) static ssize_t \
443name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
444{ \
445 struct ad7877 *ts = dev_get_drvdata(dev); \
446 ssize_t v = ad7877_read_adc(ts->spi, \
447 AD7877_READ_CHAN(name)); \
448 if (v < 0) \
449 return v; \
450 return sprintf(buf, "%u\n", (unsigned) v); \
451} \
452static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
453
454SHOW(aux1)
455SHOW(aux2)
456SHOW(aux3)
457SHOW(bat1)
458SHOW(bat2)
459SHOW(temp1)
460SHOW(temp2)
461
462static ssize_t ad7877_disable_show(struct device *dev,
463 struct device_attribute *attr, char *buf)
464{
465 struct ad7877 *ts = dev_get_drvdata(dev);
466
467 return sprintf(buf, "%u\n", ts->disabled);
468}
469
470static ssize_t ad7877_disable_store(struct device *dev,
471 struct device_attribute *attr,
472 const char *buf, size_t count)
473{
474 struct ad7877 *ts = dev_get_drvdata(dev);
475 unsigned int val;
476 int error;
477
478 error = kstrtouint(buf, 10, &val);
479 if (error)
480 return error;
481
482 if (val)
483 ad7877_disable(ts);
484 else
485 ad7877_enable(ts);
486
487 return count;
488}
489
490static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
491
492static ssize_t ad7877_dac_show(struct device *dev,
493 struct device_attribute *attr, char *buf)
494{
495 struct ad7877 *ts = dev_get_drvdata(dev);
496
497 return sprintf(buf, "%u\n", ts->dac);
498}
499
500static ssize_t ad7877_dac_store(struct device *dev,
501 struct device_attribute *attr,
502 const char *buf, size_t count)
503{
504 struct ad7877 *ts = dev_get_drvdata(dev);
505 unsigned int val;
506 int error;
507
508 error = kstrtouint(buf, 10, &val);
509 if (error)
510 return error;
511
512 mutex_lock(&ts->mutex);
513 ts->dac = val & 0xFF;
514 ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
515 mutex_unlock(&ts->mutex);
516
517 return count;
518}
519
520static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
521
522static ssize_t ad7877_gpio3_show(struct device *dev,
523 struct device_attribute *attr, char *buf)
524{
525 struct ad7877 *ts = dev_get_drvdata(dev);
526
527 return sprintf(buf, "%u\n", ts->gpio3);
528}
529
530static ssize_t ad7877_gpio3_store(struct device *dev,
531 struct device_attribute *attr,
532 const char *buf, size_t count)
533{
534 struct ad7877 *ts = dev_get_drvdata(dev);
535 unsigned int val;
536 int error;
537
538 error = kstrtouint(buf, 10, &val);
539 if (error)
540 return error;
541
542 mutex_lock(&ts->mutex);
543 ts->gpio3 = !!val;
544 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
545 (ts->gpio4 << 4) | (ts->gpio3 << 5));
546 mutex_unlock(&ts->mutex);
547
548 return count;
549}
550
551static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
552
553static ssize_t ad7877_gpio4_show(struct device *dev,
554 struct device_attribute *attr, char *buf)
555{
556 struct ad7877 *ts = dev_get_drvdata(dev);
557
558 return sprintf(buf, "%u\n", ts->gpio4);
559}
560
561static ssize_t ad7877_gpio4_store(struct device *dev,
562 struct device_attribute *attr,
563 const char *buf, size_t count)
564{
565 struct ad7877 *ts = dev_get_drvdata(dev);
566 unsigned int val;
567 int error;
568
569 error = kstrtouint(buf, 10, &val);
570 if (error)
571 return error;
572
573 mutex_lock(&ts->mutex);
574 ts->gpio4 = !!val;
575 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
576 (ts->gpio4 << 4) | (ts->gpio3 << 5));
577 mutex_unlock(&ts->mutex);
578
579 return count;
580}
581
582static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
583
584static struct attribute *ad7877_attributes[] = {
585 &dev_attr_temp1.attr,
586 &dev_attr_temp2.attr,
587 &dev_attr_aux1.attr,
588 &dev_attr_aux2.attr,
589 &dev_attr_aux3.attr,
590 &dev_attr_bat1.attr,
591 &dev_attr_bat2.attr,
592 &dev_attr_disable.attr,
593 &dev_attr_dac.attr,
594 &dev_attr_gpio3.attr,
595 &dev_attr_gpio4.attr,
596 NULL
597};
598
599static umode_t ad7877_attr_is_visible(struct kobject *kobj,
600 struct attribute *attr, int n)
601{
602 umode_t mode = attr->mode;
603
604 if (attr == &dev_attr_aux3.attr) {
605 if (gpio3)
606 mode = 0;
607 } else if (attr == &dev_attr_gpio3.attr) {
608 if (!gpio3)
609 mode = 0;
610 }
611
612 return mode;
613}
614
615static const struct attribute_group ad7877_attr_group = {
616 .is_visible = ad7877_attr_is_visible,
617 .attrs = ad7877_attributes,
618};
619
620static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
621{
622 struct spi_message *m;
623 int i;
624
625 ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
626 AD7877_POL(ts->stopacq_polarity) |
627 AD7877_AVG(ts->averaging) | AD7877_PM(1) |
628 AD7877_TMR(ts->pen_down_acc_interval) |
629 AD7877_ACQ(ts->acquisition_time) |
630 AD7877_FCD(ts->first_conversion_delay);
631
632 ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
633
634 ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
635 AD7877_READADD(AD7877_REG_XPLUS-1) |
636 AD7877_MODE_SEQ1 | AD7877_DFR;
637
638 ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
639
640 ts->cmd_dummy = 0;
641
642 m = &ts->msg;
643
644 spi_message_init(m);
645
646 m->context = ts;
647
648 ts->xfer[0].tx_buf = &ts->cmd_crtl1;
649 ts->xfer[0].len = 2;
650 ts->xfer[0].cs_change = 1;
651
652 spi_message_add_tail(&ts->xfer[0], m);
653
654 ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
655 ts->xfer[1].len = 2;
656 ts->xfer[1].cs_change = 1;
657
658 spi_message_add_tail(&ts->xfer[1], m);
659
660 for (i = 0; i < AD7877_NR_SENSE; i++) {
661 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
662 ts->xfer[i + 2].len = 2;
663 if (i < (AD7877_NR_SENSE - 1))
664 ts->xfer[i + 2].cs_change = 1;
665 spi_message_add_tail(&ts->xfer[i + 2], m);
666 }
667}
668
669static int ad7877_probe(struct spi_device *spi)
670{
671 struct ad7877 *ts;
672 struct input_dev *input_dev;
673 struct ad7877_platform_data *pdata = dev_get_platdata(&spi->dev);
674 int err;
675 u16 verify;
676
677 if (!spi->irq) {
678 dev_dbg(&spi->dev, "no IRQ?\n");
679 return -ENODEV;
680 }
681
682 if (!pdata) {
683 dev_dbg(&spi->dev, "no platform data?\n");
684 return -ENODEV;
685 }
686
687 /* don't exceed max specified SPI CLK frequency */
688 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
689 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
690 return -EINVAL;
691 }
692
693 spi->bits_per_word = 16;
694 err = spi_setup(spi);
695 if (err) {
696 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
697 return err;
698 }
699
700 ts = devm_kzalloc(&spi->dev, sizeof(struct ad7877), GFP_KERNEL);
701 if (!ts)
702 return -ENOMEM;
703
704 input_dev = devm_input_allocate_device(&spi->dev);
705 if (!input_dev)
706 return -ENOMEM;
707
708 err = devm_add_action_or_reset(&spi->dev, ad7877_disable, ts);
709 if (err)
710 return err;
711
712 spi_set_drvdata(spi, ts);
713 ts->spi = spi;
714 ts->input = input_dev;
715
716 timer_setup(&ts->timer, ad7877_timer, 0);
717 mutex_init(&ts->mutex);
718 spin_lock_init(&ts->lock);
719
720 ts->model = pdata->model ? : 7877;
721 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
722 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
723 ts->pressure_max = pdata->pressure_max ? : ~0;
724
725 ts->stopacq_polarity = pdata->stopacq_polarity;
726 ts->first_conversion_delay = pdata->first_conversion_delay;
727 ts->acquisition_time = pdata->acquisition_time;
728 ts->averaging = pdata->averaging;
729 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
730
731 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
732
733 input_dev->name = "AD7877 Touchscreen";
734 input_dev->phys = ts->phys;
735 input_dev->dev.parent = &spi->dev;
736
737 __set_bit(EV_KEY, input_dev->evbit);
738 __set_bit(BTN_TOUCH, input_dev->keybit);
739 __set_bit(EV_ABS, input_dev->evbit);
740 __set_bit(ABS_X, input_dev->absbit);
741 __set_bit(ABS_Y, input_dev->absbit);
742 __set_bit(ABS_PRESSURE, input_dev->absbit);
743
744 input_set_abs_params(input_dev, ABS_X,
745 pdata->x_min ? : 0,
746 pdata->x_max ? : MAX_12BIT,
747 0, 0);
748 input_set_abs_params(input_dev, ABS_Y,
749 pdata->y_min ? : 0,
750 pdata->y_max ? : MAX_12BIT,
751 0, 0);
752 input_set_abs_params(input_dev, ABS_PRESSURE,
753 pdata->pressure_min, pdata->pressure_max, 0, 0);
754
755 ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
756
757 verify = ad7877_read(spi, AD7877_REG_SEQ1);
758
759 if (verify != AD7877_MM_SEQUENCE) {
760 dev_err(&spi->dev, "%s: Failed to probe %s\n",
761 dev_name(&spi->dev), input_dev->name);
762 return -ENODEV;
763 }
764
765 if (gpio3)
766 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
767
768 ad7877_setup_ts_def_msg(spi, ts);
769
770 /* Request AD7877 /DAV GPIO interrupt */
771
772 err = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, ad7877_irq,
773 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
774 spi->dev.driver->name, ts);
775 if (err) {
776 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
777 return err;
778 }
779
780 err = devm_device_add_group(&spi->dev, &ad7877_attr_group);
781 if (err)
782 return err;
783
784 err = input_register_device(input_dev);
785 if (err)
786 return err;
787
788 return 0;
789}
790
791static int __maybe_unused ad7877_suspend(struct device *dev)
792{
793 struct ad7877 *ts = dev_get_drvdata(dev);
794
795 ad7877_disable(ts);
796
797 return 0;
798}
799
800static int __maybe_unused ad7877_resume(struct device *dev)
801{
802 struct ad7877 *ts = dev_get_drvdata(dev);
803
804 ad7877_enable(ts);
805
806 return 0;
807}
808
809static SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume);
810
811static struct spi_driver ad7877_driver = {
812 .driver = {
813 .name = "ad7877",
814 .pm = &ad7877_pm,
815 },
816 .probe = ad7877_probe,
817};
818
819module_spi_driver(ad7877_driver);
820
821MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
822MODULE_DESCRIPTION("AD7877 touchscreen Driver");
823MODULE_LICENSE("GPL");
824MODULE_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/init.h>
41#include <linux/delay.h>
42#include <linux/input.h>
43#include <linux/interrupt.h>
44#include <linux/pm.h>
45#include <linux/slab.h>
46#include <linux/spi/spi.h>
47#include <linux/spi/ad7877.h>
48#include <linux/module.h>
49#include <asm/irq.h>
50
51#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(100)
52
53#define MAX_SPI_FREQ_HZ 20000000
54#define MAX_12BIT ((1<<12)-1)
55
56#define AD7877_REG_ZEROS 0
57#define AD7877_REG_CTRL1 1
58#define AD7877_REG_CTRL2 2
59#define AD7877_REG_ALERT 3
60#define AD7877_REG_AUX1HIGH 4
61#define AD7877_REG_AUX1LOW 5
62#define AD7877_REG_BAT1HIGH 6
63#define AD7877_REG_BAT1LOW 7
64#define AD7877_REG_BAT2HIGH 8
65#define AD7877_REG_BAT2LOW 9
66#define AD7877_REG_TEMP1HIGH 10
67#define AD7877_REG_TEMP1LOW 11
68#define AD7877_REG_SEQ0 12
69#define AD7877_REG_SEQ1 13
70#define AD7877_REG_DAC 14
71#define AD7877_REG_NONE1 15
72#define AD7877_REG_EXTWRITE 15
73#define AD7877_REG_XPLUS 16
74#define AD7877_REG_YPLUS 17
75#define AD7877_REG_Z2 18
76#define AD7877_REG_aux1 19
77#define AD7877_REG_aux2 20
78#define AD7877_REG_aux3 21
79#define AD7877_REG_bat1 22
80#define AD7877_REG_bat2 23
81#define AD7877_REG_temp1 24
82#define AD7877_REG_temp2 25
83#define AD7877_REG_Z1 26
84#define AD7877_REG_GPIOCTRL1 27
85#define AD7877_REG_GPIOCTRL2 28
86#define AD7877_REG_GPIODATA 29
87#define AD7877_REG_NONE2 30
88#define AD7877_REG_NONE3 31
89
90#define AD7877_SEQ_YPLUS_BIT (1<<11)
91#define AD7877_SEQ_XPLUS_BIT (1<<10)
92#define AD7877_SEQ_Z2_BIT (1<<9)
93#define AD7877_SEQ_AUX1_BIT (1<<8)
94#define AD7877_SEQ_AUX2_BIT (1<<7)
95#define AD7877_SEQ_AUX3_BIT (1<<6)
96#define AD7877_SEQ_BAT1_BIT (1<<5)
97#define AD7877_SEQ_BAT2_BIT (1<<4)
98#define AD7877_SEQ_TEMP1_BIT (1<<3)
99#define AD7877_SEQ_TEMP2_BIT (1<<2)
100#define AD7877_SEQ_Z1_BIT (1<<1)
101
102enum {
103 AD7877_SEQ_YPOS = 0,
104 AD7877_SEQ_XPOS = 1,
105 AD7877_SEQ_Z2 = 2,
106 AD7877_SEQ_AUX1 = 3,
107 AD7877_SEQ_AUX2 = 4,
108 AD7877_SEQ_AUX3 = 5,
109 AD7877_SEQ_BAT1 = 6,
110 AD7877_SEQ_BAT2 = 7,
111 AD7877_SEQ_TEMP1 = 8,
112 AD7877_SEQ_TEMP2 = 9,
113 AD7877_SEQ_Z1 = 10,
114 AD7877_NR_SENSE = 11,
115};
116
117/* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */
118#define AD7877_DAC_CONF 0x1
119
120/* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */
121#define AD7877_EXTW_GPIO_3_CONF 0x1C4
122#define AD7877_EXTW_GPIO_DATA 0x200
123
124/* Control REG 2 */
125#define AD7877_TMR(x) ((x & 0x3) << 0)
126#define AD7877_REF(x) ((x & 0x1) << 2)
127#define AD7877_POL(x) ((x & 0x1) << 3)
128#define AD7877_FCD(x) ((x & 0x3) << 4)
129#define AD7877_PM(x) ((x & 0x3) << 6)
130#define AD7877_ACQ(x) ((x & 0x3) << 8)
131#define AD7877_AVG(x) ((x & 0x3) << 10)
132
133/* Control REG 1 */
134#define AD7877_SER (1 << 11) /* non-differential */
135#define AD7877_DFR (0 << 11) /* differential */
136
137#define AD7877_MODE_NOC (0) /* Do not convert */
138#define AD7877_MODE_SCC (1) /* Single channel conversion */
139#define AD7877_MODE_SEQ0 (2) /* Sequence 0 in Slave Mode */
140#define AD7877_MODE_SEQ1 (3) /* Sequence 1 in Master Mode */
141
142#define AD7877_CHANADD(x) ((x&0xF)<<7)
143#define AD7877_READADD(x) ((x)<<2)
144#define AD7877_WRITEADD(x) ((x)<<12)
145
146#define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \
147 AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \
148 AD7877_READADD(AD7877_REG_ ## x))
149
150#define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \
151 AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT)
152
153/*
154 * Non-touchscreen sensors only use single-ended conversions.
155 */
156
157struct ser_req {
158 u16 reset;
159 u16 ref_on;
160 u16 command;
161 struct spi_message msg;
162 struct spi_transfer xfer[6];
163
164 /*
165 * DMA (thus cache coherency maintenance) requires the
166 * transfer buffers to live in their own cache lines.
167 */
168 u16 sample ____cacheline_aligned;
169};
170
171struct ad7877 {
172 struct input_dev *input;
173 char phys[32];
174
175 struct spi_device *spi;
176 u16 model;
177 u16 vref_delay_usecs;
178 u16 x_plate_ohms;
179 u16 pressure_max;
180
181 u16 cmd_crtl1;
182 u16 cmd_crtl2;
183 u16 cmd_dummy;
184 u16 dac;
185
186 u8 stopacq_polarity;
187 u8 first_conversion_delay;
188 u8 acquisition_time;
189 u8 averaging;
190 u8 pen_down_acc_interval;
191
192 struct spi_transfer xfer[AD7877_NR_SENSE + 2];
193 struct spi_message msg;
194
195 struct mutex mutex;
196 bool disabled; /* P: mutex */
197 bool gpio3; /* P: mutex */
198 bool gpio4; /* P: mutex */
199
200 spinlock_t lock;
201 struct timer_list timer; /* P: lock */
202
203 /*
204 * DMA (thus cache coherency maintenance) requires the
205 * transfer buffers to live in their own cache lines.
206 */
207 u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned;
208};
209
210static bool gpio3;
211module_param(gpio3, bool, 0);
212MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
213
214/*
215 * ad7877_read/write are only used for initial setup and for sysfs controls.
216 * The main traffic is done using spi_async() in the interrupt handler.
217 */
218
219static int ad7877_read(struct spi_device *spi, u16 reg)
220{
221 struct ser_req *req;
222 int status, ret;
223
224 req = kzalloc(sizeof *req, GFP_KERNEL);
225 if (!req)
226 return -ENOMEM;
227
228 spi_message_init(&req->msg);
229
230 req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) |
231 AD7877_READADD(reg));
232 req->xfer[0].tx_buf = &req->command;
233 req->xfer[0].len = 2;
234 req->xfer[0].cs_change = 1;
235
236 req->xfer[1].rx_buf = &req->sample;
237 req->xfer[1].len = 2;
238
239 spi_message_add_tail(&req->xfer[0], &req->msg);
240 spi_message_add_tail(&req->xfer[1], &req->msg);
241
242 status = spi_sync(spi, &req->msg);
243 ret = status ? : req->sample;
244
245 kfree(req);
246
247 return ret;
248}
249
250static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
251{
252 struct ser_req *req;
253 int status;
254
255 req = kzalloc(sizeof *req, GFP_KERNEL);
256 if (!req)
257 return -ENOMEM;
258
259 spi_message_init(&req->msg);
260
261 req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
262 req->xfer[0].tx_buf = &req->command;
263 req->xfer[0].len = 2;
264
265 spi_message_add_tail(&req->xfer[0], &req->msg);
266
267 status = spi_sync(spi, &req->msg);
268
269 kfree(req);
270
271 return status;
272}
273
274static int ad7877_read_adc(struct spi_device *spi, unsigned command)
275{
276 struct ad7877 *ts = dev_get_drvdata(&spi->dev);
277 struct ser_req *req;
278 int status;
279 int sample;
280 int i;
281
282 req = kzalloc(sizeof *req, GFP_KERNEL);
283 if (!req)
284 return -ENOMEM;
285
286 spi_message_init(&req->msg);
287
288 /* activate reference, so it has time to settle; */
289 req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) |
290 AD7877_POL(ts->stopacq_polarity) |
291 AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) |
292 AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0);
293
294 req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
295
296 req->command = (u16) command;
297
298 req->xfer[0].tx_buf = &req->reset;
299 req->xfer[0].len = 2;
300 req->xfer[0].cs_change = 1;
301
302 req->xfer[1].tx_buf = &req->ref_on;
303 req->xfer[1].len = 2;
304 req->xfer[1].delay_usecs = ts->vref_delay_usecs;
305 req->xfer[1].cs_change = 1;
306
307 req->xfer[2].tx_buf = &req->command;
308 req->xfer[2].len = 2;
309 req->xfer[2].delay_usecs = ts->vref_delay_usecs;
310 req->xfer[2].cs_change = 1;
311
312 req->xfer[3].rx_buf = &req->sample;
313 req->xfer[3].len = 2;
314 req->xfer[3].cs_change = 1;
315
316 req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/
317 req->xfer[4].len = 2;
318 req->xfer[4].cs_change = 1;
319
320 req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/
321 req->xfer[5].len = 2;
322
323 /* group all the transfers together, so we can't interfere with
324 * reading touchscreen state; disable penirq while sampling
325 */
326 for (i = 0; i < 6; i++)
327 spi_message_add_tail(&req->xfer[i], &req->msg);
328
329 status = spi_sync(spi, &req->msg);
330 sample = req->sample;
331
332 kfree(req);
333
334 return status ? : sample;
335}
336
337static int ad7877_process_data(struct ad7877 *ts)
338{
339 struct input_dev *input_dev = ts->input;
340 unsigned Rt;
341 u16 x, y, z1, z2;
342
343 x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
344 y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
345 z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
346 z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
347
348 /*
349 * The samples processed here are already preprocessed by the AD7877.
350 * The preprocessing function consists of an averaging filter.
351 * The combination of 'first conversion delay' and averaging provides a robust solution,
352 * discarding the spurious noise in the signal and keeping only the data of interest.
353 * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h)
354 * Other user-programmable conversion controls include variable acquisition time,
355 * and first conversion delay. Up to 16 averages can be taken per conversion.
356 */
357
358 if (likely(x && z1)) {
359 /* compute touch pressure resistance using equation #1 */
360 Rt = (z2 - z1) * x * ts->x_plate_ohms;
361 Rt /= z1;
362 Rt = (Rt + 2047) >> 12;
363
364 /*
365 * Sample found inconsistent, pressure is beyond
366 * the maximum. Don't report it to user space.
367 */
368 if (Rt > ts->pressure_max)
369 return -EINVAL;
370
371 if (!timer_pending(&ts->timer))
372 input_report_key(input_dev, BTN_TOUCH, 1);
373
374 input_report_abs(input_dev, ABS_X, x);
375 input_report_abs(input_dev, ABS_Y, y);
376 input_report_abs(input_dev, ABS_PRESSURE, Rt);
377 input_sync(input_dev);
378
379 return 0;
380 }
381
382 return -EINVAL;
383}
384
385static inline void ad7877_ts_event_release(struct ad7877 *ts)
386{
387 struct input_dev *input_dev = ts->input;
388
389 input_report_abs(input_dev, ABS_PRESSURE, 0);
390 input_report_key(input_dev, BTN_TOUCH, 0);
391 input_sync(input_dev);
392}
393
394static void ad7877_timer(unsigned long handle)
395{
396 struct ad7877 *ts = (void *)handle;
397 unsigned long flags;
398
399 spin_lock_irqsave(&ts->lock, flags);
400 ad7877_ts_event_release(ts);
401 spin_unlock_irqrestore(&ts->lock, flags);
402}
403
404static irqreturn_t ad7877_irq(int irq, void *handle)
405{
406 struct ad7877 *ts = handle;
407 unsigned long flags;
408 int error;
409
410 error = spi_sync(ts->spi, &ts->msg);
411 if (error) {
412 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
413 goto out;
414 }
415
416 spin_lock_irqsave(&ts->lock, flags);
417 error = ad7877_process_data(ts);
418 if (!error)
419 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
420 spin_unlock_irqrestore(&ts->lock, flags);
421
422out:
423 return IRQ_HANDLED;
424}
425
426static void ad7877_disable(struct ad7877 *ts)
427{
428 mutex_lock(&ts->mutex);
429
430 if (!ts->disabled) {
431 ts->disabled = true;
432 disable_irq(ts->spi->irq);
433
434 if (del_timer_sync(&ts->timer))
435 ad7877_ts_event_release(ts);
436 }
437
438 /*
439 * We know the chip's in lowpower mode since we always
440 * leave it that way after every request
441 */
442
443 mutex_unlock(&ts->mutex);
444}
445
446static void ad7877_enable(struct ad7877 *ts)
447{
448 mutex_lock(&ts->mutex);
449
450 if (ts->disabled) {
451 ts->disabled = false;
452 enable_irq(ts->spi->irq);
453 }
454
455 mutex_unlock(&ts->mutex);
456}
457
458#define SHOW(name) static ssize_t \
459name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
460{ \
461 struct ad7877 *ts = dev_get_drvdata(dev); \
462 ssize_t v = ad7877_read_adc(ts->spi, \
463 AD7877_READ_CHAN(name)); \
464 if (v < 0) \
465 return v; \
466 return sprintf(buf, "%u\n", (unsigned) v); \
467} \
468static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
469
470SHOW(aux1)
471SHOW(aux2)
472SHOW(aux3)
473SHOW(bat1)
474SHOW(bat2)
475SHOW(temp1)
476SHOW(temp2)
477
478static ssize_t ad7877_disable_show(struct device *dev,
479 struct device_attribute *attr, char *buf)
480{
481 struct ad7877 *ts = dev_get_drvdata(dev);
482
483 return sprintf(buf, "%u\n", ts->disabled);
484}
485
486static ssize_t ad7877_disable_store(struct device *dev,
487 struct device_attribute *attr,
488 const char *buf, size_t count)
489{
490 struct ad7877 *ts = dev_get_drvdata(dev);
491 unsigned int val;
492 int error;
493
494 error = kstrtouint(buf, 10, &val);
495 if (error)
496 return error;
497
498 if (val)
499 ad7877_disable(ts);
500 else
501 ad7877_enable(ts);
502
503 return count;
504}
505
506static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
507
508static ssize_t ad7877_dac_show(struct device *dev,
509 struct device_attribute *attr, char *buf)
510{
511 struct ad7877 *ts = dev_get_drvdata(dev);
512
513 return sprintf(buf, "%u\n", ts->dac);
514}
515
516static ssize_t ad7877_dac_store(struct device *dev,
517 struct device_attribute *attr,
518 const char *buf, size_t count)
519{
520 struct ad7877 *ts = dev_get_drvdata(dev);
521 unsigned int val;
522 int error;
523
524 error = kstrtouint(buf, 10, &val);
525 if (error)
526 return error;
527
528 mutex_lock(&ts->mutex);
529 ts->dac = val & 0xFF;
530 ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
531 mutex_unlock(&ts->mutex);
532
533 return count;
534}
535
536static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
537
538static ssize_t ad7877_gpio3_show(struct device *dev,
539 struct device_attribute *attr, char *buf)
540{
541 struct ad7877 *ts = dev_get_drvdata(dev);
542
543 return sprintf(buf, "%u\n", ts->gpio3);
544}
545
546static ssize_t ad7877_gpio3_store(struct device *dev,
547 struct device_attribute *attr,
548 const char *buf, size_t count)
549{
550 struct ad7877 *ts = dev_get_drvdata(dev);
551 unsigned int val;
552 int error;
553
554 error = kstrtouint(buf, 10, &val);
555 if (error)
556 return error;
557
558 mutex_lock(&ts->mutex);
559 ts->gpio3 = !!val;
560 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
561 (ts->gpio4 << 4) | (ts->gpio3 << 5));
562 mutex_unlock(&ts->mutex);
563
564 return count;
565}
566
567static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
568
569static ssize_t ad7877_gpio4_show(struct device *dev,
570 struct device_attribute *attr, char *buf)
571{
572 struct ad7877 *ts = dev_get_drvdata(dev);
573
574 return sprintf(buf, "%u\n", ts->gpio4);
575}
576
577static ssize_t ad7877_gpio4_store(struct device *dev,
578 struct device_attribute *attr,
579 const char *buf, size_t count)
580{
581 struct ad7877 *ts = dev_get_drvdata(dev);
582 unsigned int val;
583 int error;
584
585 error = kstrtouint(buf, 10, &val);
586 if (error)
587 return error;
588
589 mutex_lock(&ts->mutex);
590 ts->gpio4 = !!val;
591 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
592 (ts->gpio4 << 4) | (ts->gpio3 << 5));
593 mutex_unlock(&ts->mutex);
594
595 return count;
596}
597
598static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
599
600static struct attribute *ad7877_attributes[] = {
601 &dev_attr_temp1.attr,
602 &dev_attr_temp2.attr,
603 &dev_attr_aux1.attr,
604 &dev_attr_aux2.attr,
605 &dev_attr_aux3.attr,
606 &dev_attr_bat1.attr,
607 &dev_attr_bat2.attr,
608 &dev_attr_disable.attr,
609 &dev_attr_dac.attr,
610 &dev_attr_gpio3.attr,
611 &dev_attr_gpio4.attr,
612 NULL
613};
614
615static umode_t ad7877_attr_is_visible(struct kobject *kobj,
616 struct attribute *attr, int n)
617{
618 umode_t mode = attr->mode;
619
620 if (attr == &dev_attr_aux3.attr) {
621 if (gpio3)
622 mode = 0;
623 } else if (attr == &dev_attr_gpio3.attr) {
624 if (!gpio3)
625 mode = 0;
626 }
627
628 return mode;
629}
630
631static const struct attribute_group ad7877_attr_group = {
632 .is_visible = ad7877_attr_is_visible,
633 .attrs = ad7877_attributes,
634};
635
636static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
637{
638 struct spi_message *m;
639 int i;
640
641 ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
642 AD7877_POL(ts->stopacq_polarity) |
643 AD7877_AVG(ts->averaging) | AD7877_PM(1) |
644 AD7877_TMR(ts->pen_down_acc_interval) |
645 AD7877_ACQ(ts->acquisition_time) |
646 AD7877_FCD(ts->first_conversion_delay);
647
648 ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
649
650 ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
651 AD7877_READADD(AD7877_REG_XPLUS-1) |
652 AD7877_MODE_SEQ1 | AD7877_DFR;
653
654 ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
655
656 ts->cmd_dummy = 0;
657
658 m = &ts->msg;
659
660 spi_message_init(m);
661
662 m->context = ts;
663
664 ts->xfer[0].tx_buf = &ts->cmd_crtl1;
665 ts->xfer[0].len = 2;
666 ts->xfer[0].cs_change = 1;
667
668 spi_message_add_tail(&ts->xfer[0], m);
669
670 ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
671 ts->xfer[1].len = 2;
672 ts->xfer[1].cs_change = 1;
673
674 spi_message_add_tail(&ts->xfer[1], m);
675
676 for (i = 0; i < AD7877_NR_SENSE; i++) {
677 ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
678 ts->xfer[i + 2].len = 2;
679 if (i < (AD7877_NR_SENSE - 1))
680 ts->xfer[i + 2].cs_change = 1;
681 spi_message_add_tail(&ts->xfer[i + 2], m);
682 }
683}
684
685static int __devinit ad7877_probe(struct spi_device *spi)
686{
687 struct ad7877 *ts;
688 struct input_dev *input_dev;
689 struct ad7877_platform_data *pdata = spi->dev.platform_data;
690 int err;
691 u16 verify;
692
693 if (!spi->irq) {
694 dev_dbg(&spi->dev, "no IRQ?\n");
695 return -ENODEV;
696 }
697
698 if (!pdata) {
699 dev_dbg(&spi->dev, "no platform data?\n");
700 return -ENODEV;
701 }
702
703 /* don't exceed max specified SPI CLK frequency */
704 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
705 dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
706 return -EINVAL;
707 }
708
709 spi->bits_per_word = 16;
710 err = spi_setup(spi);
711 if (err) {
712 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
713 return err;
714 }
715
716 ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
717 input_dev = input_allocate_device();
718 if (!ts || !input_dev) {
719 err = -ENOMEM;
720 goto err_free_mem;
721 }
722
723 dev_set_drvdata(&spi->dev, ts);
724 ts->spi = spi;
725 ts->input = input_dev;
726
727 setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts);
728 mutex_init(&ts->mutex);
729 spin_lock_init(&ts->lock);
730
731 ts->model = pdata->model ? : 7877;
732 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
733 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
734 ts->pressure_max = pdata->pressure_max ? : ~0;
735
736 ts->stopacq_polarity = pdata->stopacq_polarity;
737 ts->first_conversion_delay = pdata->first_conversion_delay;
738 ts->acquisition_time = pdata->acquisition_time;
739 ts->averaging = pdata->averaging;
740 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
741
742 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
743
744 input_dev->name = "AD7877 Touchscreen";
745 input_dev->phys = ts->phys;
746 input_dev->dev.parent = &spi->dev;
747
748 __set_bit(EV_KEY, input_dev->evbit);
749 __set_bit(BTN_TOUCH, input_dev->keybit);
750 __set_bit(EV_ABS, input_dev->evbit);
751 __set_bit(ABS_X, input_dev->absbit);
752 __set_bit(ABS_Y, input_dev->absbit);
753 __set_bit(ABS_PRESSURE, input_dev->absbit);
754
755 input_set_abs_params(input_dev, ABS_X,
756 pdata->x_min ? : 0,
757 pdata->x_max ? : MAX_12BIT,
758 0, 0);
759 input_set_abs_params(input_dev, ABS_Y,
760 pdata->y_min ? : 0,
761 pdata->y_max ? : MAX_12BIT,
762 0, 0);
763 input_set_abs_params(input_dev, ABS_PRESSURE,
764 pdata->pressure_min, pdata->pressure_max, 0, 0);
765
766 ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
767
768 verify = ad7877_read(spi, AD7877_REG_SEQ1);
769
770 if (verify != AD7877_MM_SEQUENCE){
771 dev_err(&spi->dev, "%s: Failed to probe %s\n",
772 dev_name(&spi->dev), input_dev->name);
773 err = -ENODEV;
774 goto err_free_mem;
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 = request_threaded_irq(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 goto err_free_mem;
790 }
791
792 err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group);
793 if (err)
794 goto err_free_irq;
795
796 err = input_register_device(input_dev);
797 if (err)
798 goto err_remove_attr_group;
799
800 return 0;
801
802err_remove_attr_group:
803 sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
804err_free_irq:
805 free_irq(spi->irq, ts);
806err_free_mem:
807 input_free_device(input_dev);
808 kfree(ts);
809 dev_set_drvdata(&spi->dev, NULL);
810 return err;
811}
812
813static int __devexit ad7877_remove(struct spi_device *spi)
814{
815 struct ad7877 *ts = dev_get_drvdata(&spi->dev);
816
817 sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
818
819 ad7877_disable(ts);
820 free_irq(ts->spi->irq, ts);
821
822 input_unregister_device(ts->input);
823 kfree(ts);
824
825 dev_dbg(&spi->dev, "unregistered touchscreen\n");
826 dev_set_drvdata(&spi->dev, NULL);
827
828 return 0;
829}
830
831#ifdef CONFIG_PM_SLEEP
832static int ad7877_suspend(struct device *dev)
833{
834 struct ad7877 *ts = dev_get_drvdata(dev);
835
836 ad7877_disable(ts);
837
838 return 0;
839}
840
841static int ad7877_resume(struct device *dev)
842{
843 struct ad7877 *ts = dev_get_drvdata(dev);
844
845 ad7877_enable(ts);
846
847 return 0;
848}
849#endif
850
851static SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume);
852
853static struct spi_driver ad7877_driver = {
854 .driver = {
855 .name = "ad7877",
856 .owner = THIS_MODULE,
857 .pm = &ad7877_pm,
858 },
859 .probe = ad7877_probe,
860 .remove = __devexit_p(ad7877_remove),
861};
862
863module_spi_driver(ad7877_driver);
864
865MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
866MODULE_DESCRIPTION("AD7877 touchscreen Driver");
867MODULE_LICENSE("GPL");
868MODULE_ALIAS("spi:ad7877");