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
87 enum {
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
142 struct 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
156 struct 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
195 static bool gpio3;
196 module_param(gpio3, bool, 0);
197 MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
198
ad7877_read(struct spi_device * spi,u16 reg)199 static 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
ad7877_write(struct spi_device * spi,u16 reg,u16 val)230 static 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
ad7877_read_adc(struct spi_device * spi,unsigned command)254 static 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
ad7877_process_data(struct ad7877 * ts)319 static 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
ad7877_ts_event_release(struct ad7877 * ts)367 static 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
ad7877_timer(struct timer_list * t)376 static 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
ad7877_irq(int irq,void * handle)386 static 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
404 out:
405 return IRQ_HANDLED;
406 }
407
ad7877_disable(void * data)408 static 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
ad7877_enable(struct ad7877 * ts)430 static 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 \
443 name ## _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 } \
452 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
453
454 SHOW(aux1)
SHOW(aux2)455 SHOW(aux2)
456 SHOW(aux3)
457 SHOW(bat1)
458 SHOW(bat2)
459 SHOW(temp1)
460 SHOW(temp2)
461
462 static 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
ad7877_disable_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)470 static 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
490 static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
491
ad7877_dac_show(struct device * dev,struct device_attribute * attr,char * buf)492 static 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
ad7877_dac_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)500 static 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
520 static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
521
ad7877_gpio3_show(struct device * dev,struct device_attribute * attr,char * buf)522 static 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
ad7877_gpio3_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)530 static 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
551 static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
552
ad7877_gpio4_show(struct device * dev,struct device_attribute * attr,char * buf)553 static 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
ad7877_gpio4_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)561 static 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
582 static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
583
584 static 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
ad7877_attr_is_visible(struct kobject * kobj,struct attribute * attr,int n)599 static 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
615 static const struct attribute_group ad7877_attr_group = {
616 .is_visible = ad7877_attr_is_visible,
617 .attrs = ad7877_attributes,
618 };
619
ad7877_setup_ts_def_msg(struct spi_device * spi,struct ad7877 * ts)620 static 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
ad7877_probe(struct spi_device * spi)669 static 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
ad7877_suspend(struct device * dev)791 static int 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
ad7877_resume(struct device * dev)800 static int 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
809 static DEFINE_SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume);
810
811 static struct spi_driver ad7877_driver = {
812 .driver = {
813 .name = "ad7877",
814 .pm = pm_sleep_ptr(&ad7877_pm),
815 },
816 .probe = ad7877_probe,
817 };
818
819 module_spi_driver(ad7877_driver);
820
821 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
822 MODULE_DESCRIPTION("AD7877 touchscreen Driver");
823 MODULE_LICENSE("GPL");
824 MODULE_ALIAS("spi:ad7877");
825