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1/*
2 * ADS7846 based touchscreen and sensor driver
3 *
4 * Copyright (c) 2005 David Brownell
5 * Copyright (c) 2006 Nokia Corporation
6 * Various changes: Imre Deak <imre.deak@nokia.com>
7 *
8 * Using code from:
9 * - corgi_ts.c
10 * Copyright (C) 2004-2005 Richard Purdie
11 * - omap_ts.[hc], ads7846.h, ts_osk.c
12 * Copyright (C) 2002 MontaVista Software
13 * Copyright (C) 2004 Texas Instruments
14 * Copyright (C) 2005 Dirk Behme
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License version 2 as
18 * published by the Free Software Foundation.
19 */
20#include <linux/types.h>
21#include <linux/hwmon.h>
22#include <linux/err.h>
23#include <linux/sched.h>
24#include <linux/delay.h>
25#include <linux/input.h>
26#include <linux/interrupt.h>
27#include <linux/slab.h>
28#include <linux/pm.h>
29#include <linux/of.h>
30#include <linux/of_gpio.h>
31#include <linux/of_device.h>
32#include <linux/gpio.h>
33#include <linux/spi/spi.h>
34#include <linux/spi/ads7846.h>
35#include <linux/regulator/consumer.h>
36#include <linux/module.h>
37#include <asm/irq.h>
38
39/*
40 * This code has been heavily tested on a Nokia 770, and lightly
41 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
42 * TSC2046 is just newer ads7846 silicon.
43 * Support for ads7843 tested on Atmel at91sam926x-EK.
44 * Support for ads7845 has only been stubbed in.
45 * Support for Analog Devices AD7873 and AD7843 tested.
46 *
47 * IRQ handling needs a workaround because of a shortcoming in handling
48 * edge triggered IRQs on some platforms like the OMAP1/2. These
49 * platforms don't handle the ARM lazy IRQ disabling properly, thus we
50 * have to maintain our own SW IRQ disabled status. This should be
51 * removed as soon as the affected platform's IRQ handling is fixed.
52 *
53 * App note sbaa036 talks in more detail about accurate sampling...
54 * that ought to help in situations like LCDs inducing noise (which
55 * can also be helped by using synch signals) and more generally.
56 * This driver tries to utilize the measures described in the app
57 * note. The strength of filtering can be set in the board-* specific
58 * files.
59 */
60
61#define TS_POLL_DELAY 1 /* ms delay before the first sample */
62#define TS_POLL_PERIOD 5 /* ms delay between samples */
63
64/* this driver doesn't aim at the peak continuous sample rate */
65#define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
66
67struct ts_event {
68 /*
69 * For portability, we can't read 12 bit values using SPI (which
70 * would make the controller deliver them as native byte order u16
71 * with msbs zeroed). Instead, we read them as two 8-bit values,
72 * *** WHICH NEED BYTESWAPPING *** and range adjustment.
73 */
74 u16 x;
75 u16 y;
76 u16 z1, z2;
77 bool ignore;
78 u8 x_buf[3];
79 u8 y_buf[3];
80};
81
82/*
83 * We allocate this separately to avoid cache line sharing issues when
84 * driver is used with DMA-based SPI controllers (like atmel_spi) on
85 * systems where main memory is not DMA-coherent (most non-x86 boards).
86 */
87struct ads7846_packet {
88 u8 read_x, read_y, read_z1, read_z2, pwrdown;
89 u16 dummy; /* for the pwrdown read */
90 struct ts_event tc;
91 /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */
92 u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
93};
94
95struct ads7846 {
96 struct input_dev *input;
97 char phys[32];
98 char name[32];
99
100 struct spi_device *spi;
101 struct regulator *reg;
102
103#if IS_ENABLED(CONFIG_HWMON)
104 struct device *hwmon;
105#endif
106
107 u16 model;
108 u16 vref_mv;
109 u16 vref_delay_usecs;
110 u16 x_plate_ohms;
111 u16 pressure_max;
112
113 bool swap_xy;
114 bool use_internal;
115
116 struct ads7846_packet *packet;
117
118 struct spi_transfer xfer[18];
119 struct spi_message msg[5];
120 int msg_count;
121 wait_queue_head_t wait;
122
123 bool pendown;
124
125 int read_cnt;
126 int read_rep;
127 int last_read;
128
129 u16 debounce_max;
130 u16 debounce_tol;
131 u16 debounce_rep;
132
133 u16 penirq_recheck_delay_usecs;
134
135 struct mutex lock;
136 bool stopped; /* P: lock */
137 bool disabled; /* P: lock */
138 bool suspended; /* P: lock */
139
140 int (*filter)(void *data, int data_idx, int *val);
141 void *filter_data;
142 void (*filter_cleanup)(void *data);
143 int (*get_pendown_state)(void);
144 int gpio_pendown;
145
146 void (*wait_for_sync)(void);
147};
148
149/* leave chip selected when we're done, for quicker re-select? */
150#if 0
151#define CS_CHANGE(xfer) ((xfer).cs_change = 1)
152#else
153#define CS_CHANGE(xfer) ((xfer).cs_change = 0)
154#endif
155
156/*--------------------------------------------------------------------------*/
157
158/* The ADS7846 has touchscreen and other sensors.
159 * Earlier ads784x chips are somewhat compatible.
160 */
161#define ADS_START (1 << 7)
162#define ADS_A2A1A0_d_y (1 << 4) /* differential */
163#define ADS_A2A1A0_d_z1 (3 << 4) /* differential */
164#define ADS_A2A1A0_d_z2 (4 << 4) /* differential */
165#define ADS_A2A1A0_d_x (5 << 4) /* differential */
166#define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */
167#define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */
168#define ADS_A2A1A0_vaux (6 << 4) /* non-differential */
169#define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */
170#define ADS_8_BIT (1 << 3)
171#define ADS_12_BIT (0 << 3)
172#define ADS_SER (1 << 2) /* non-differential */
173#define ADS_DFR (0 << 2) /* differential */
174#define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */
175#define ADS_PD10_ADC_ON (1 << 0) /* ADC on */
176#define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */
177#define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */
178
179#define MAX_12BIT ((1<<12)-1)
180
181/* leave ADC powered up (disables penirq) between differential samples */
182#define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
183 | ADS_12_BIT | ADS_DFR | \
184 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
185
186#define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref))
187#define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref))
188#define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref))
189
190#define READ_X(vref) (READ_12BIT_DFR(x, 1, vref))
191#define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */
192
193/* single-ended samples need to first power up reference voltage;
194 * we leave both ADC and VREF powered
195 */
196#define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
197 | ADS_12_BIT | ADS_SER)
198
199#define REF_ON (READ_12BIT_DFR(x, 1, 1))
200#define REF_OFF (READ_12BIT_DFR(y, 0, 0))
201
202/* Must be called with ts->lock held */
203static void ads7846_stop(struct ads7846 *ts)
204{
205 if (!ts->disabled && !ts->suspended) {
206 /* Signal IRQ thread to stop polling and disable the handler. */
207 ts->stopped = true;
208 mb();
209 wake_up(&ts->wait);
210 disable_irq(ts->spi->irq);
211 }
212}
213
214/* Must be called with ts->lock held */
215static void ads7846_restart(struct ads7846 *ts)
216{
217 if (!ts->disabled && !ts->suspended) {
218 /* Tell IRQ thread that it may poll the device. */
219 ts->stopped = false;
220 mb();
221 enable_irq(ts->spi->irq);
222 }
223}
224
225/* Must be called with ts->lock held */
226static void __ads7846_disable(struct ads7846 *ts)
227{
228 ads7846_stop(ts);
229 regulator_disable(ts->reg);
230
231 /*
232 * We know the chip's in low power mode since we always
233 * leave it that way after every request
234 */
235}
236
237/* Must be called with ts->lock held */
238static void __ads7846_enable(struct ads7846 *ts)
239{
240 int error;
241
242 error = regulator_enable(ts->reg);
243 if (error != 0)
244 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error);
245
246 ads7846_restart(ts);
247}
248
249static void ads7846_disable(struct ads7846 *ts)
250{
251 mutex_lock(&ts->lock);
252
253 if (!ts->disabled) {
254
255 if (!ts->suspended)
256 __ads7846_disable(ts);
257
258 ts->disabled = true;
259 }
260
261 mutex_unlock(&ts->lock);
262}
263
264static void ads7846_enable(struct ads7846 *ts)
265{
266 mutex_lock(&ts->lock);
267
268 if (ts->disabled) {
269
270 ts->disabled = false;
271
272 if (!ts->suspended)
273 __ads7846_enable(ts);
274 }
275
276 mutex_unlock(&ts->lock);
277}
278
279/*--------------------------------------------------------------------------*/
280
281/*
282 * Non-touchscreen sensors only use single-ended conversions.
283 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
284 * ads7846 lets that pin be unconnected, to use internal vREF.
285 */
286
287struct ser_req {
288 u8 ref_on;
289 u8 command;
290 u8 ref_off;
291 u16 scratch;
292 struct spi_message msg;
293 struct spi_transfer xfer[6];
294 /*
295 * DMA (thus cache coherency maintenance) requires the
296 * transfer buffers to live in their own cache lines.
297 */
298 __be16 sample ____cacheline_aligned;
299};
300
301struct ads7845_ser_req {
302 u8 command[3];
303 struct spi_message msg;
304 struct spi_transfer xfer[2];
305 /*
306 * DMA (thus cache coherency maintenance) requires the
307 * transfer buffers to live in their own cache lines.
308 */
309 u8 sample[3] ____cacheline_aligned;
310};
311
312static int ads7846_read12_ser(struct device *dev, unsigned command)
313{
314 struct spi_device *spi = to_spi_device(dev);
315 struct ads7846 *ts = dev_get_drvdata(dev);
316 struct ser_req *req;
317 int status;
318
319 req = kzalloc(sizeof *req, GFP_KERNEL);
320 if (!req)
321 return -ENOMEM;
322
323 spi_message_init(&req->msg);
324
325 /* maybe turn on internal vREF, and let it settle */
326 if (ts->use_internal) {
327 req->ref_on = REF_ON;
328 req->xfer[0].tx_buf = &req->ref_on;
329 req->xfer[0].len = 1;
330 spi_message_add_tail(&req->xfer[0], &req->msg);
331
332 req->xfer[1].rx_buf = &req->scratch;
333 req->xfer[1].len = 2;
334
335 /* for 1uF, settle for 800 usec; no cap, 100 usec. */
336 req->xfer[1].delay_usecs = ts->vref_delay_usecs;
337 spi_message_add_tail(&req->xfer[1], &req->msg);
338
339 /* Enable reference voltage */
340 command |= ADS_PD10_REF_ON;
341 }
342
343 /* Enable ADC in every case */
344 command |= ADS_PD10_ADC_ON;
345
346 /* take sample */
347 req->command = (u8) command;
348 req->xfer[2].tx_buf = &req->command;
349 req->xfer[2].len = 1;
350 spi_message_add_tail(&req->xfer[2], &req->msg);
351
352 req->xfer[3].rx_buf = &req->sample;
353 req->xfer[3].len = 2;
354 spi_message_add_tail(&req->xfer[3], &req->msg);
355
356 /* REVISIT: take a few more samples, and compare ... */
357
358 /* converter in low power mode & enable PENIRQ */
359 req->ref_off = PWRDOWN;
360 req->xfer[4].tx_buf = &req->ref_off;
361 req->xfer[4].len = 1;
362 spi_message_add_tail(&req->xfer[4], &req->msg);
363
364 req->xfer[5].rx_buf = &req->scratch;
365 req->xfer[5].len = 2;
366 CS_CHANGE(req->xfer[5]);
367 spi_message_add_tail(&req->xfer[5], &req->msg);
368
369 mutex_lock(&ts->lock);
370 ads7846_stop(ts);
371 status = spi_sync(spi, &req->msg);
372 ads7846_restart(ts);
373 mutex_unlock(&ts->lock);
374
375 if (status == 0) {
376 /* on-wire is a must-ignore bit, a BE12 value, then padding */
377 status = be16_to_cpu(req->sample);
378 status = status >> 3;
379 status &= 0x0fff;
380 }
381
382 kfree(req);
383 return status;
384}
385
386static int ads7845_read12_ser(struct device *dev, unsigned command)
387{
388 struct spi_device *spi = to_spi_device(dev);
389 struct ads7846 *ts = dev_get_drvdata(dev);
390 struct ads7845_ser_req *req;
391 int status;
392
393 req = kzalloc(sizeof *req, GFP_KERNEL);
394 if (!req)
395 return -ENOMEM;
396
397 spi_message_init(&req->msg);
398
399 req->command[0] = (u8) command;
400 req->xfer[0].tx_buf = req->command;
401 req->xfer[0].rx_buf = req->sample;
402 req->xfer[0].len = 3;
403 spi_message_add_tail(&req->xfer[0], &req->msg);
404
405 mutex_lock(&ts->lock);
406 ads7846_stop(ts);
407 status = spi_sync(spi, &req->msg);
408 ads7846_restart(ts);
409 mutex_unlock(&ts->lock);
410
411 if (status == 0) {
412 /* BE12 value, then padding */
413 status = be16_to_cpu(*((u16 *)&req->sample[1]));
414 status = status >> 3;
415 status &= 0x0fff;
416 }
417
418 kfree(req);
419 return status;
420}
421
422#if IS_ENABLED(CONFIG_HWMON)
423
424#define SHOW(name, var, adjust) static ssize_t \
425name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
426{ \
427 struct ads7846 *ts = dev_get_drvdata(dev); \
428 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \
429 READ_12BIT_SER(var)); \
430 if (v < 0) \
431 return v; \
432 return sprintf(buf, "%u\n", adjust(ts, v)); \
433} \
434static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
435
436
437/* Sysfs conventions report temperatures in millidegrees Celsius.
438 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
439 * accuracy scheme without calibration data. For now we won't try either;
440 * userspace sees raw sensor values, and must scale/calibrate appropriately.
441 */
442static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
443{
444 return v;
445}
446
447SHOW(temp0, temp0, null_adjust) /* temp1_input */
448SHOW(temp1, temp1, null_adjust) /* temp2_input */
449
450
451/* sysfs conventions report voltages in millivolts. We can convert voltages
452 * if we know vREF. userspace may need to scale vAUX to match the board's
453 * external resistors; we assume that vBATT only uses the internal ones.
454 */
455static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
456{
457 unsigned retval = v;
458
459 /* external resistors may scale vAUX into 0..vREF */
460 retval *= ts->vref_mv;
461 retval = retval >> 12;
462
463 return retval;
464}
465
466static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
467{
468 unsigned retval = vaux_adjust(ts, v);
469
470 /* ads7846 has a resistor ladder to scale this signal down */
471 if (ts->model == 7846)
472 retval *= 4;
473
474 return retval;
475}
476
477SHOW(in0_input, vaux, vaux_adjust)
478SHOW(in1_input, vbatt, vbatt_adjust)
479
480static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr,
481 int index)
482{
483 struct device *dev = container_of(kobj, struct device, kobj);
484 struct ads7846 *ts = dev_get_drvdata(dev);
485
486 if (ts->model == 7843 && index < 2) /* in0, in1 */
487 return 0;
488 if (ts->model == 7845 && index != 2) /* in0 */
489 return 0;
490
491 return attr->mode;
492}
493
494static struct attribute *ads7846_attributes[] = {
495 &dev_attr_temp0.attr, /* 0 */
496 &dev_attr_temp1.attr, /* 1 */
497 &dev_attr_in0_input.attr, /* 2 */
498 &dev_attr_in1_input.attr, /* 3 */
499 NULL,
500};
501
502static struct attribute_group ads7846_attr_group = {
503 .attrs = ads7846_attributes,
504 .is_visible = ads7846_is_visible,
505};
506__ATTRIBUTE_GROUPS(ads7846_attr);
507
508static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
509{
510 /* hwmon sensors need a reference voltage */
511 switch (ts->model) {
512 case 7846:
513 if (!ts->vref_mv) {
514 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
515 ts->vref_mv = 2500;
516 ts->use_internal = true;
517 }
518 break;
519 case 7845:
520 case 7843:
521 if (!ts->vref_mv) {
522 dev_warn(&spi->dev,
523 "external vREF for ADS%d not specified\n",
524 ts->model);
525 return 0;
526 }
527 break;
528 }
529
530 ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias,
531 ts, ads7846_attr_groups);
532 if (IS_ERR(ts->hwmon))
533 return PTR_ERR(ts->hwmon);
534
535 return 0;
536}
537
538static void ads784x_hwmon_unregister(struct spi_device *spi,
539 struct ads7846 *ts)
540{
541 if (ts->hwmon)
542 hwmon_device_unregister(ts->hwmon);
543}
544
545#else
546static inline int ads784x_hwmon_register(struct spi_device *spi,
547 struct ads7846 *ts)
548{
549 return 0;
550}
551
552static inline void ads784x_hwmon_unregister(struct spi_device *spi,
553 struct ads7846 *ts)
554{
555}
556#endif
557
558static ssize_t ads7846_pen_down_show(struct device *dev,
559 struct device_attribute *attr, char *buf)
560{
561 struct ads7846 *ts = dev_get_drvdata(dev);
562
563 return sprintf(buf, "%u\n", ts->pendown);
564}
565
566static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
567
568static ssize_t ads7846_disable_show(struct device *dev,
569 struct device_attribute *attr, char *buf)
570{
571 struct ads7846 *ts = dev_get_drvdata(dev);
572
573 return sprintf(buf, "%u\n", ts->disabled);
574}
575
576static ssize_t ads7846_disable_store(struct device *dev,
577 struct device_attribute *attr,
578 const char *buf, size_t count)
579{
580 struct ads7846 *ts = dev_get_drvdata(dev);
581 unsigned int i;
582 int err;
583
584 err = kstrtouint(buf, 10, &i);
585 if (err)
586 return err;
587
588 if (i)
589 ads7846_disable(ts);
590 else
591 ads7846_enable(ts);
592
593 return count;
594}
595
596static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
597
598static struct attribute *ads784x_attributes[] = {
599 &dev_attr_pen_down.attr,
600 &dev_attr_disable.attr,
601 NULL,
602};
603
604static struct attribute_group ads784x_attr_group = {
605 .attrs = ads784x_attributes,
606};
607
608/*--------------------------------------------------------------------------*/
609
610static int get_pendown_state(struct ads7846 *ts)
611{
612 if (ts->get_pendown_state)
613 return ts->get_pendown_state();
614
615 return !gpio_get_value(ts->gpio_pendown);
616}
617
618static void null_wait_for_sync(void)
619{
620}
621
622static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
623{
624 struct ads7846 *ts = ads;
625
626 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
627 /* Start over collecting consistent readings. */
628 ts->read_rep = 0;
629 /*
630 * Repeat it, if this was the first read or the read
631 * wasn't consistent enough.
632 */
633 if (ts->read_cnt < ts->debounce_max) {
634 ts->last_read = *val;
635 ts->read_cnt++;
636 return ADS7846_FILTER_REPEAT;
637 } else {
638 /*
639 * Maximum number of debouncing reached and still
640 * not enough number of consistent readings. Abort
641 * the whole sample, repeat it in the next sampling
642 * period.
643 */
644 ts->read_cnt = 0;
645 return ADS7846_FILTER_IGNORE;
646 }
647 } else {
648 if (++ts->read_rep > ts->debounce_rep) {
649 /*
650 * Got a good reading for this coordinate,
651 * go for the next one.
652 */
653 ts->read_cnt = 0;
654 ts->read_rep = 0;
655 return ADS7846_FILTER_OK;
656 } else {
657 /* Read more values that are consistent. */
658 ts->read_cnt++;
659 return ADS7846_FILTER_REPEAT;
660 }
661 }
662}
663
664static int ads7846_no_filter(void *ads, int data_idx, int *val)
665{
666 return ADS7846_FILTER_OK;
667}
668
669static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
670{
671 struct spi_transfer *t =
672 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
673
674 if (ts->model == 7845) {
675 return be16_to_cpup((__be16 *)&(((char*)t->rx_buf)[1])) >> 3;
676 } else {
677 /*
678 * adjust: on-wire is a must-ignore bit, a BE12 value, then
679 * padding; built from two 8 bit values written msb-first.
680 */
681 return be16_to_cpup((__be16 *)t->rx_buf) >> 3;
682 }
683}
684
685static void ads7846_update_value(struct spi_message *m, int val)
686{
687 struct spi_transfer *t =
688 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
689
690 *(u16 *)t->rx_buf = val;
691}
692
693static void ads7846_read_state(struct ads7846 *ts)
694{
695 struct ads7846_packet *packet = ts->packet;
696 struct spi_message *m;
697 int msg_idx = 0;
698 int val;
699 int action;
700 int error;
701
702 while (msg_idx < ts->msg_count) {
703
704 ts->wait_for_sync();
705
706 m = &ts->msg[msg_idx];
707 error = spi_sync(ts->spi, m);
708 if (error) {
709 dev_err(&ts->spi->dev, "spi_async --> %d\n", error);
710 packet->tc.ignore = true;
711 return;
712 }
713
714 /*
715 * Last message is power down request, no need to convert
716 * or filter the value.
717 */
718 if (msg_idx < ts->msg_count - 1) {
719
720 val = ads7846_get_value(ts, m);
721
722 action = ts->filter(ts->filter_data, msg_idx, &val);
723 switch (action) {
724 case ADS7846_FILTER_REPEAT:
725 continue;
726
727 case ADS7846_FILTER_IGNORE:
728 packet->tc.ignore = true;
729 msg_idx = ts->msg_count - 1;
730 continue;
731
732 case ADS7846_FILTER_OK:
733 ads7846_update_value(m, val);
734 packet->tc.ignore = false;
735 msg_idx++;
736 break;
737
738 default:
739 BUG();
740 }
741 } else {
742 msg_idx++;
743 }
744 }
745}
746
747static void ads7846_report_state(struct ads7846 *ts)
748{
749 struct ads7846_packet *packet = ts->packet;
750 unsigned int Rt;
751 u16 x, y, z1, z2;
752
753 /*
754 * ads7846_get_value() does in-place conversion (including byte swap)
755 * from on-the-wire format as part of debouncing to get stable
756 * readings.
757 */
758 if (ts->model == 7845) {
759 x = *(u16 *)packet->tc.x_buf;
760 y = *(u16 *)packet->tc.y_buf;
761 z1 = 0;
762 z2 = 0;
763 } else {
764 x = packet->tc.x;
765 y = packet->tc.y;
766 z1 = packet->tc.z1;
767 z2 = packet->tc.z2;
768 }
769
770 /* range filtering */
771 if (x == MAX_12BIT)
772 x = 0;
773
774 if (ts->model == 7843) {
775 Rt = ts->pressure_max / 2;
776 } else if (ts->model == 7845) {
777 if (get_pendown_state(ts))
778 Rt = ts->pressure_max / 2;
779 else
780 Rt = 0;
781 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
782 } else if (likely(x && z1)) {
783 /* compute touch pressure resistance using equation #2 */
784 Rt = z2;
785 Rt -= z1;
786 Rt *= x;
787 Rt *= ts->x_plate_ohms;
788 Rt /= z1;
789 Rt = (Rt + 2047) >> 12;
790 } else {
791 Rt = 0;
792 }
793
794 /*
795 * Sample found inconsistent by debouncing or pressure is beyond
796 * the maximum. Don't report it to user space, repeat at least
797 * once more the measurement
798 */
799 if (packet->tc.ignore || Rt > ts->pressure_max) {
800 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
801 packet->tc.ignore, Rt);
802 return;
803 }
804
805 /*
806 * Maybe check the pendown state before reporting. This discards
807 * false readings when the pen is lifted.
808 */
809 if (ts->penirq_recheck_delay_usecs) {
810 udelay(ts->penirq_recheck_delay_usecs);
811 if (!get_pendown_state(ts))
812 Rt = 0;
813 }
814
815 /*
816 * NOTE: We can't rely on the pressure to determine the pen down
817 * state, even this controller has a pressure sensor. The pressure
818 * value can fluctuate for quite a while after lifting the pen and
819 * in some cases may not even settle at the expected value.
820 *
821 * The only safe way to check for the pen up condition is in the
822 * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
823 */
824 if (Rt) {
825 struct input_dev *input = ts->input;
826
827 if (ts->swap_xy)
828 swap(x, y);
829
830 if (!ts->pendown) {
831 input_report_key(input, BTN_TOUCH, 1);
832 ts->pendown = true;
833 dev_vdbg(&ts->spi->dev, "DOWN\n");
834 }
835
836 input_report_abs(input, ABS_X, x);
837 input_report_abs(input, ABS_Y, y);
838 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
839
840 input_sync(input);
841 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
842 }
843}
844
845static irqreturn_t ads7846_hard_irq(int irq, void *handle)
846{
847 struct ads7846 *ts = handle;
848
849 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
850}
851
852
853static irqreturn_t ads7846_irq(int irq, void *handle)
854{
855 struct ads7846 *ts = handle;
856
857 /* Start with a small delay before checking pendown state */
858 msleep(TS_POLL_DELAY);
859
860 while (!ts->stopped && get_pendown_state(ts)) {
861
862 /* pen is down, continue with the measurement */
863 ads7846_read_state(ts);
864
865 if (!ts->stopped)
866 ads7846_report_state(ts);
867
868 wait_event_timeout(ts->wait, ts->stopped,
869 msecs_to_jiffies(TS_POLL_PERIOD));
870 }
871
872 if (ts->pendown) {
873 struct input_dev *input = ts->input;
874
875 input_report_key(input, BTN_TOUCH, 0);
876 input_report_abs(input, ABS_PRESSURE, 0);
877 input_sync(input);
878
879 ts->pendown = false;
880 dev_vdbg(&ts->spi->dev, "UP\n");
881 }
882
883 return IRQ_HANDLED;
884}
885
886#ifdef CONFIG_PM_SLEEP
887static int ads7846_suspend(struct device *dev)
888{
889 struct ads7846 *ts = dev_get_drvdata(dev);
890
891 mutex_lock(&ts->lock);
892
893 if (!ts->suspended) {
894
895 if (!ts->disabled)
896 __ads7846_disable(ts);
897
898 if (device_may_wakeup(&ts->spi->dev))
899 enable_irq_wake(ts->spi->irq);
900
901 ts->suspended = true;
902 }
903
904 mutex_unlock(&ts->lock);
905
906 return 0;
907}
908
909static int ads7846_resume(struct device *dev)
910{
911 struct ads7846 *ts = dev_get_drvdata(dev);
912
913 mutex_lock(&ts->lock);
914
915 if (ts->suspended) {
916
917 ts->suspended = false;
918
919 if (device_may_wakeup(&ts->spi->dev))
920 disable_irq_wake(ts->spi->irq);
921
922 if (!ts->disabled)
923 __ads7846_enable(ts);
924 }
925
926 mutex_unlock(&ts->lock);
927
928 return 0;
929}
930#endif
931
932static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
933
934static int ads7846_setup_pendown(struct spi_device *spi,
935 struct ads7846 *ts,
936 const struct ads7846_platform_data *pdata)
937{
938 int err;
939
940 /*
941 * REVISIT when the irq can be triggered active-low, or if for some
942 * reason the touchscreen isn't hooked up, we don't need to access
943 * the pendown state.
944 */
945
946 if (pdata->get_pendown_state) {
947 ts->get_pendown_state = pdata->get_pendown_state;
948 } else if (gpio_is_valid(pdata->gpio_pendown)) {
949
950 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
951 "ads7846_pendown");
952 if (err) {
953 dev_err(&spi->dev,
954 "failed to request/setup pendown GPIO%d: %d\n",
955 pdata->gpio_pendown, err);
956 return err;
957 }
958
959 ts->gpio_pendown = pdata->gpio_pendown;
960
961 if (pdata->gpio_pendown_debounce)
962 gpio_set_debounce(pdata->gpio_pendown,
963 pdata->gpio_pendown_debounce);
964 } else {
965 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
966 return -EINVAL;
967 }
968
969 return 0;
970}
971
972/*
973 * Set up the transfers to read touchscreen state; this assumes we
974 * use formula #2 for pressure, not #3.
975 */
976static void ads7846_setup_spi_msg(struct ads7846 *ts,
977 const struct ads7846_platform_data *pdata)
978{
979 struct spi_message *m = &ts->msg[0];
980 struct spi_transfer *x = ts->xfer;
981 struct ads7846_packet *packet = ts->packet;
982 int vref = pdata->keep_vref_on;
983
984 if (ts->model == 7873) {
985 /*
986 * The AD7873 is almost identical to the ADS7846
987 * keep VREF off during differential/ratiometric
988 * conversion modes.
989 */
990 ts->model = 7846;
991 vref = 0;
992 }
993
994 ts->msg_count = 1;
995 spi_message_init(m);
996 m->context = ts;
997
998 if (ts->model == 7845) {
999 packet->read_y_cmd[0] = READ_Y(vref);
1000 packet->read_y_cmd[1] = 0;
1001 packet->read_y_cmd[2] = 0;
1002 x->tx_buf = &packet->read_y_cmd[0];
1003 x->rx_buf = &packet->tc.y_buf[0];
1004 x->len = 3;
1005 spi_message_add_tail(x, m);
1006 } else {
1007 /* y- still on; turn on only y+ (and ADC) */
1008 packet->read_y = READ_Y(vref);
1009 x->tx_buf = &packet->read_y;
1010 x->len = 1;
1011 spi_message_add_tail(x, m);
1012
1013 x++;
1014 x->rx_buf = &packet->tc.y;
1015 x->len = 2;
1016 spi_message_add_tail(x, m);
1017 }
1018
1019 /*
1020 * The first sample after switching drivers can be low quality;
1021 * optionally discard it, using a second one after the signals
1022 * have had enough time to stabilize.
1023 */
1024 if (pdata->settle_delay_usecs) {
1025 x->delay_usecs = pdata->settle_delay_usecs;
1026
1027 x++;
1028 x->tx_buf = &packet->read_y;
1029 x->len = 1;
1030 spi_message_add_tail(x, m);
1031
1032 x++;
1033 x->rx_buf = &packet->tc.y;
1034 x->len = 2;
1035 spi_message_add_tail(x, m);
1036 }
1037
1038 ts->msg_count++;
1039 m++;
1040 spi_message_init(m);
1041 m->context = ts;
1042
1043 if (ts->model == 7845) {
1044 x++;
1045 packet->read_x_cmd[0] = READ_X(vref);
1046 packet->read_x_cmd[1] = 0;
1047 packet->read_x_cmd[2] = 0;
1048 x->tx_buf = &packet->read_x_cmd[0];
1049 x->rx_buf = &packet->tc.x_buf[0];
1050 x->len = 3;
1051 spi_message_add_tail(x, m);
1052 } else {
1053 /* turn y- off, x+ on, then leave in lowpower */
1054 x++;
1055 packet->read_x = READ_X(vref);
1056 x->tx_buf = &packet->read_x;
1057 x->len = 1;
1058 spi_message_add_tail(x, m);
1059
1060 x++;
1061 x->rx_buf = &packet->tc.x;
1062 x->len = 2;
1063 spi_message_add_tail(x, m);
1064 }
1065
1066 /* ... maybe discard first sample ... */
1067 if (pdata->settle_delay_usecs) {
1068 x->delay_usecs = pdata->settle_delay_usecs;
1069
1070 x++;
1071 x->tx_buf = &packet->read_x;
1072 x->len = 1;
1073 spi_message_add_tail(x, m);
1074
1075 x++;
1076 x->rx_buf = &packet->tc.x;
1077 x->len = 2;
1078 spi_message_add_tail(x, m);
1079 }
1080
1081 /* turn y+ off, x- on; we'll use formula #2 */
1082 if (ts->model == 7846) {
1083 ts->msg_count++;
1084 m++;
1085 spi_message_init(m);
1086 m->context = ts;
1087
1088 x++;
1089 packet->read_z1 = READ_Z1(vref);
1090 x->tx_buf = &packet->read_z1;
1091 x->len = 1;
1092 spi_message_add_tail(x, m);
1093
1094 x++;
1095 x->rx_buf = &packet->tc.z1;
1096 x->len = 2;
1097 spi_message_add_tail(x, m);
1098
1099 /* ... maybe discard first sample ... */
1100 if (pdata->settle_delay_usecs) {
1101 x->delay_usecs = pdata->settle_delay_usecs;
1102
1103 x++;
1104 x->tx_buf = &packet->read_z1;
1105 x->len = 1;
1106 spi_message_add_tail(x, m);
1107
1108 x++;
1109 x->rx_buf = &packet->tc.z1;
1110 x->len = 2;
1111 spi_message_add_tail(x, m);
1112 }
1113
1114 ts->msg_count++;
1115 m++;
1116 spi_message_init(m);
1117 m->context = ts;
1118
1119 x++;
1120 packet->read_z2 = READ_Z2(vref);
1121 x->tx_buf = &packet->read_z2;
1122 x->len = 1;
1123 spi_message_add_tail(x, m);
1124
1125 x++;
1126 x->rx_buf = &packet->tc.z2;
1127 x->len = 2;
1128 spi_message_add_tail(x, m);
1129
1130 /* ... maybe discard first sample ... */
1131 if (pdata->settle_delay_usecs) {
1132 x->delay_usecs = pdata->settle_delay_usecs;
1133
1134 x++;
1135 x->tx_buf = &packet->read_z2;
1136 x->len = 1;
1137 spi_message_add_tail(x, m);
1138
1139 x++;
1140 x->rx_buf = &packet->tc.z2;
1141 x->len = 2;
1142 spi_message_add_tail(x, m);
1143 }
1144 }
1145
1146 /* power down */
1147 ts->msg_count++;
1148 m++;
1149 spi_message_init(m);
1150 m->context = ts;
1151
1152 if (ts->model == 7845) {
1153 x++;
1154 packet->pwrdown_cmd[0] = PWRDOWN;
1155 packet->pwrdown_cmd[1] = 0;
1156 packet->pwrdown_cmd[2] = 0;
1157 x->tx_buf = &packet->pwrdown_cmd[0];
1158 x->len = 3;
1159 } else {
1160 x++;
1161 packet->pwrdown = PWRDOWN;
1162 x->tx_buf = &packet->pwrdown;
1163 x->len = 1;
1164 spi_message_add_tail(x, m);
1165
1166 x++;
1167 x->rx_buf = &packet->dummy;
1168 x->len = 2;
1169 }
1170
1171 CS_CHANGE(*x);
1172 spi_message_add_tail(x, m);
1173}
1174
1175#ifdef CONFIG_OF
1176static const struct of_device_id ads7846_dt_ids[] = {
1177 { .compatible = "ti,tsc2046", .data = (void *) 7846 },
1178 { .compatible = "ti,ads7843", .data = (void *) 7843 },
1179 { .compatible = "ti,ads7845", .data = (void *) 7845 },
1180 { .compatible = "ti,ads7846", .data = (void *) 7846 },
1181 { .compatible = "ti,ads7873", .data = (void *) 7873 },
1182 { }
1183};
1184MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1185
1186static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1187{
1188 struct ads7846_platform_data *pdata;
1189 struct device_node *node = dev->of_node;
1190 const struct of_device_id *match;
1191
1192 if (!node) {
1193 dev_err(dev, "Device does not have associated DT data\n");
1194 return ERR_PTR(-EINVAL);
1195 }
1196
1197 match = of_match_device(ads7846_dt_ids, dev);
1198 if (!match) {
1199 dev_err(dev, "Unknown device model\n");
1200 return ERR_PTR(-EINVAL);
1201 }
1202
1203 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1204 if (!pdata)
1205 return ERR_PTR(-ENOMEM);
1206
1207 pdata->model = (unsigned long)match->data;
1208
1209 of_property_read_u16(node, "ti,vref-delay-usecs",
1210 &pdata->vref_delay_usecs);
1211 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
1212 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
1213
1214 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
1215
1216 of_property_read_u16(node, "ti,settle-delay-usec",
1217 &pdata->settle_delay_usecs);
1218 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
1219 &pdata->penirq_recheck_delay_usecs);
1220
1221 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1222 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1223
1224 of_property_read_u16(node, "ti,x-min", &pdata->x_min);
1225 of_property_read_u16(node, "ti,y-min", &pdata->y_min);
1226 of_property_read_u16(node, "ti,x-max", &pdata->x_max);
1227 of_property_read_u16(node, "ti,y-max", &pdata->y_max);
1228
1229 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1230 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1231
1232 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1233 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1234 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1235
1236 of_property_read_u32(node, "ti,pendown-gpio-debounce",
1237 &pdata->gpio_pendown_debounce);
1238
1239 pdata->wakeup = of_property_read_bool(node, "linux,wakeup");
1240
1241 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1242
1243 return pdata;
1244}
1245#else
1246static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1247{
1248 dev_err(dev, "no platform data defined\n");
1249 return ERR_PTR(-EINVAL);
1250}
1251#endif
1252
1253static int ads7846_probe(struct spi_device *spi)
1254{
1255 const struct ads7846_platform_data *pdata;
1256 struct ads7846 *ts;
1257 struct ads7846_packet *packet;
1258 struct input_dev *input_dev;
1259 unsigned long irq_flags;
1260 int err;
1261
1262 if (!spi->irq) {
1263 dev_dbg(&spi->dev, "no IRQ?\n");
1264 return -EINVAL;
1265 }
1266
1267 /* don't exceed max specified sample rate */
1268 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1269 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1270 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1271 return -EINVAL;
1272 }
1273
1274 /*
1275 * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1276 * that even if the hardware can do that, the SPI controller driver
1277 * may not. So we stick to very-portable 8 bit words, both RX and TX.
1278 */
1279 spi->bits_per_word = 8;
1280 spi->mode = SPI_MODE_0;
1281 err = spi_setup(spi);
1282 if (err < 0)
1283 return err;
1284
1285 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1286 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1287 input_dev = input_allocate_device();
1288 if (!ts || !packet || !input_dev) {
1289 err = -ENOMEM;
1290 goto err_free_mem;
1291 }
1292
1293 spi_set_drvdata(spi, ts);
1294
1295 ts->packet = packet;
1296 ts->spi = spi;
1297 ts->input = input_dev;
1298
1299 mutex_init(&ts->lock);
1300 init_waitqueue_head(&ts->wait);
1301
1302 pdata = dev_get_platdata(&spi->dev);
1303 if (!pdata) {
1304 pdata = ads7846_probe_dt(&spi->dev);
1305 if (IS_ERR(pdata))
1306 return PTR_ERR(pdata);
1307 }
1308
1309 ts->model = pdata->model ? : 7846;
1310 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1311 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1312 ts->pressure_max = pdata->pressure_max ? : ~0;
1313
1314 ts->vref_mv = pdata->vref_mv;
1315 ts->swap_xy = pdata->swap_xy;
1316
1317 if (pdata->filter != NULL) {
1318 if (pdata->filter_init != NULL) {
1319 err = pdata->filter_init(pdata, &ts->filter_data);
1320 if (err < 0)
1321 goto err_free_mem;
1322 }
1323 ts->filter = pdata->filter;
1324 ts->filter_cleanup = pdata->filter_cleanup;
1325 } else if (pdata->debounce_max) {
1326 ts->debounce_max = pdata->debounce_max;
1327 if (ts->debounce_max < 2)
1328 ts->debounce_max = 2;
1329 ts->debounce_tol = pdata->debounce_tol;
1330 ts->debounce_rep = pdata->debounce_rep;
1331 ts->filter = ads7846_debounce_filter;
1332 ts->filter_data = ts;
1333 } else {
1334 ts->filter = ads7846_no_filter;
1335 }
1336
1337 err = ads7846_setup_pendown(spi, ts, pdata);
1338 if (err)
1339 goto err_cleanup_filter;
1340
1341 if (pdata->penirq_recheck_delay_usecs)
1342 ts->penirq_recheck_delay_usecs =
1343 pdata->penirq_recheck_delay_usecs;
1344
1345 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1346
1347 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1348 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1349
1350 input_dev->name = ts->name;
1351 input_dev->phys = ts->phys;
1352 input_dev->dev.parent = &spi->dev;
1353
1354 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1355 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1356 input_set_abs_params(input_dev, ABS_X,
1357 pdata->x_min ? : 0,
1358 pdata->x_max ? : MAX_12BIT,
1359 0, 0);
1360 input_set_abs_params(input_dev, ABS_Y,
1361 pdata->y_min ? : 0,
1362 pdata->y_max ? : MAX_12BIT,
1363 0, 0);
1364 input_set_abs_params(input_dev, ABS_PRESSURE,
1365 pdata->pressure_min, pdata->pressure_max, 0, 0);
1366
1367 ads7846_setup_spi_msg(ts, pdata);
1368
1369 ts->reg = regulator_get(&spi->dev, "vcc");
1370 if (IS_ERR(ts->reg)) {
1371 err = PTR_ERR(ts->reg);
1372 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1373 goto err_free_gpio;
1374 }
1375
1376 err = regulator_enable(ts->reg);
1377 if (err) {
1378 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1379 goto err_put_regulator;
1380 }
1381
1382 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1383 irq_flags |= IRQF_ONESHOT;
1384
1385 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1386 irq_flags, spi->dev.driver->name, ts);
1387 if (err && !pdata->irq_flags) {
1388 dev_info(&spi->dev,
1389 "trying pin change workaround on irq %d\n", spi->irq);
1390 irq_flags |= IRQF_TRIGGER_RISING;
1391 err = request_threaded_irq(spi->irq,
1392 ads7846_hard_irq, ads7846_irq,
1393 irq_flags, spi->dev.driver->name, ts);
1394 }
1395
1396 if (err) {
1397 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1398 goto err_disable_regulator;
1399 }
1400
1401 err = ads784x_hwmon_register(spi, ts);
1402 if (err)
1403 goto err_free_irq;
1404
1405 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1406
1407 /*
1408 * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1409 * the touchscreen, in case it's not connected.
1410 */
1411 if (ts->model == 7845)
1412 ads7845_read12_ser(&spi->dev, PWRDOWN);
1413 else
1414 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1415
1416 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1417 if (err)
1418 goto err_remove_hwmon;
1419
1420 err = input_register_device(input_dev);
1421 if (err)
1422 goto err_remove_attr_group;
1423
1424 device_init_wakeup(&spi->dev, pdata->wakeup);
1425
1426 /*
1427 * If device does not carry platform data we must have allocated it
1428 * when parsing DT data.
1429 */
1430 if (!dev_get_platdata(&spi->dev))
1431 devm_kfree(&spi->dev, (void *)pdata);
1432
1433 return 0;
1434
1435 err_remove_attr_group:
1436 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1437 err_remove_hwmon:
1438 ads784x_hwmon_unregister(spi, ts);
1439 err_free_irq:
1440 free_irq(spi->irq, ts);
1441 err_disable_regulator:
1442 regulator_disable(ts->reg);
1443 err_put_regulator:
1444 regulator_put(ts->reg);
1445 err_free_gpio:
1446 if (!ts->get_pendown_state)
1447 gpio_free(ts->gpio_pendown);
1448 err_cleanup_filter:
1449 if (ts->filter_cleanup)
1450 ts->filter_cleanup(ts->filter_data);
1451 err_free_mem:
1452 input_free_device(input_dev);
1453 kfree(packet);
1454 kfree(ts);
1455 return err;
1456}
1457
1458static int ads7846_remove(struct spi_device *spi)
1459{
1460 struct ads7846 *ts = spi_get_drvdata(spi);
1461
1462 device_init_wakeup(&spi->dev, false);
1463
1464 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1465
1466 ads7846_disable(ts);
1467 free_irq(ts->spi->irq, ts);
1468
1469 input_unregister_device(ts->input);
1470
1471 ads784x_hwmon_unregister(spi, ts);
1472
1473 regulator_disable(ts->reg);
1474 regulator_put(ts->reg);
1475
1476 if (!ts->get_pendown_state) {
1477 /*
1478 * If we are not using specialized pendown method we must
1479 * have been relying on gpio we set up ourselves.
1480 */
1481 gpio_free(ts->gpio_pendown);
1482 }
1483
1484 if (ts->filter_cleanup)
1485 ts->filter_cleanup(ts->filter_data);
1486
1487 kfree(ts->packet);
1488 kfree(ts);
1489
1490 dev_dbg(&spi->dev, "unregistered touchscreen\n");
1491
1492 return 0;
1493}
1494
1495static struct spi_driver ads7846_driver = {
1496 .driver = {
1497 .name = "ads7846",
1498 .owner = THIS_MODULE,
1499 .pm = &ads7846_pm,
1500 .of_match_table = of_match_ptr(ads7846_dt_ids),
1501 },
1502 .probe = ads7846_probe,
1503 .remove = ads7846_remove,
1504};
1505
1506module_spi_driver(ads7846_driver);
1507
1508MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1509MODULE_LICENSE("GPL");
1510MODULE_ALIAS("spi:ads7846");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * ADS7846 based touchscreen and sensor driver
4 *
5 * Copyright (c) 2005 David Brownell
6 * Copyright (c) 2006 Nokia Corporation
7 * Various changes: Imre Deak <imre.deak@nokia.com>
8 *
9 * Using code from:
10 * - corgi_ts.c
11 * Copyright (C) 2004-2005 Richard Purdie
12 * - omap_ts.[hc], ads7846.h, ts_osk.c
13 * Copyright (C) 2002 MontaVista Software
14 * Copyright (C) 2004 Texas Instruments
15 * Copyright (C) 2005 Dirk Behme
16 */
17#include <linux/types.h>
18#include <linux/hwmon.h>
19#include <linux/err.h>
20#include <linux/sched.h>
21#include <linux/delay.h>
22#include <linux/input.h>
23#include <linux/input/touchscreen.h>
24#include <linux/interrupt.h>
25#include <linux/slab.h>
26#include <linux/pm.h>
27#include <linux/of.h>
28#include <linux/of_gpio.h>
29#include <linux/of_device.h>
30#include <linux/gpio.h>
31#include <linux/spi/spi.h>
32#include <linux/spi/ads7846.h>
33#include <linux/regulator/consumer.h>
34#include <linux/module.h>
35#include <asm/irq.h>
36
37/*
38 * This code has been heavily tested on a Nokia 770, and lightly
39 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
40 * TSC2046 is just newer ads7846 silicon.
41 * Support for ads7843 tested on Atmel at91sam926x-EK.
42 * Support for ads7845 has only been stubbed in.
43 * Support for Analog Devices AD7873 and AD7843 tested.
44 *
45 * IRQ handling needs a workaround because of a shortcoming in handling
46 * edge triggered IRQs on some platforms like the OMAP1/2. These
47 * platforms don't handle the ARM lazy IRQ disabling properly, thus we
48 * have to maintain our own SW IRQ disabled status. This should be
49 * removed as soon as the affected platform's IRQ handling is fixed.
50 *
51 * App note sbaa036 talks in more detail about accurate sampling...
52 * that ought to help in situations like LCDs inducing noise (which
53 * can also be helped by using synch signals) and more generally.
54 * This driver tries to utilize the measures described in the app
55 * note. The strength of filtering can be set in the board-* specific
56 * files.
57 */
58
59#define TS_POLL_DELAY 1 /* ms delay before the first sample */
60#define TS_POLL_PERIOD 5 /* ms delay between samples */
61
62/* this driver doesn't aim at the peak continuous sample rate */
63#define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
64
65struct ts_event {
66 /*
67 * For portability, we can't read 12 bit values using SPI (which
68 * would make the controller deliver them as native byte order u16
69 * with msbs zeroed). Instead, we read them as two 8-bit values,
70 * *** WHICH NEED BYTESWAPPING *** and range adjustment.
71 */
72 u16 x;
73 u16 y;
74 u16 z1, z2;
75 bool ignore;
76 u8 x_buf[3];
77 u8 y_buf[3];
78};
79
80/*
81 * We allocate this separately to avoid cache line sharing issues when
82 * driver is used with DMA-based SPI controllers (like atmel_spi) on
83 * systems where main memory is not DMA-coherent (most non-x86 boards).
84 */
85struct ads7846_packet {
86 u8 read_x, read_y, read_z1, read_z2, pwrdown;
87 u16 dummy; /* for the pwrdown read */
88 struct ts_event tc;
89 /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */
90 u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
91};
92
93struct ads7846 {
94 struct input_dev *input;
95 char phys[32];
96 char name[32];
97
98 struct spi_device *spi;
99 struct regulator *reg;
100
101#if IS_ENABLED(CONFIG_HWMON)
102 struct device *hwmon;
103#endif
104
105 u16 model;
106 u16 vref_mv;
107 u16 vref_delay_usecs;
108 u16 x_plate_ohms;
109 u16 pressure_max;
110
111 bool swap_xy;
112 bool use_internal;
113
114 struct ads7846_packet *packet;
115
116 struct spi_transfer xfer[18];
117 struct spi_message msg[5];
118 int msg_count;
119 wait_queue_head_t wait;
120
121 bool pendown;
122
123 int read_cnt;
124 int read_rep;
125 int last_read;
126
127 u16 debounce_max;
128 u16 debounce_tol;
129 u16 debounce_rep;
130
131 u16 penirq_recheck_delay_usecs;
132
133 struct touchscreen_properties core_prop;
134
135 struct mutex lock;
136 bool stopped; /* P: lock */
137 bool disabled; /* P: lock */
138 bool suspended; /* P: lock */
139
140 int (*filter)(void *data, int data_idx, int *val);
141 void *filter_data;
142 void (*filter_cleanup)(void *data);
143 int (*get_pendown_state)(void);
144 int gpio_pendown;
145
146 void (*wait_for_sync)(void);
147};
148
149/* leave chip selected when we're done, for quicker re-select? */
150#if 0
151#define CS_CHANGE(xfer) ((xfer).cs_change = 1)
152#else
153#define CS_CHANGE(xfer) ((xfer).cs_change = 0)
154#endif
155
156/*--------------------------------------------------------------------------*/
157
158/* The ADS7846 has touchscreen and other sensors.
159 * Earlier ads784x chips are somewhat compatible.
160 */
161#define ADS_START (1 << 7)
162#define ADS_A2A1A0_d_y (1 << 4) /* differential */
163#define ADS_A2A1A0_d_z1 (3 << 4) /* differential */
164#define ADS_A2A1A0_d_z2 (4 << 4) /* differential */
165#define ADS_A2A1A0_d_x (5 << 4) /* differential */
166#define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */
167#define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */
168#define ADS_A2A1A0_vaux (6 << 4) /* non-differential */
169#define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */
170#define ADS_8_BIT (1 << 3)
171#define ADS_12_BIT (0 << 3)
172#define ADS_SER (1 << 2) /* non-differential */
173#define ADS_DFR (0 << 2) /* differential */
174#define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */
175#define ADS_PD10_ADC_ON (1 << 0) /* ADC on */
176#define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */
177#define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */
178
179#define MAX_12BIT ((1<<12)-1)
180
181/* leave ADC powered up (disables penirq) between differential samples */
182#define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
183 | ADS_12_BIT | ADS_DFR | \
184 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
185
186#define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref))
187#define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref))
188#define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref))
189
190#define READ_X(vref) (READ_12BIT_DFR(x, 1, vref))
191#define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */
192
193/* single-ended samples need to first power up reference voltage;
194 * we leave both ADC and VREF powered
195 */
196#define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
197 | ADS_12_BIT | ADS_SER)
198
199#define REF_ON (READ_12BIT_DFR(x, 1, 1))
200#define REF_OFF (READ_12BIT_DFR(y, 0, 0))
201
202/* Must be called with ts->lock held */
203static void ads7846_stop(struct ads7846 *ts)
204{
205 if (!ts->disabled && !ts->suspended) {
206 /* Signal IRQ thread to stop polling and disable the handler. */
207 ts->stopped = true;
208 mb();
209 wake_up(&ts->wait);
210 disable_irq(ts->spi->irq);
211 }
212}
213
214/* Must be called with ts->lock held */
215static void ads7846_restart(struct ads7846 *ts)
216{
217 if (!ts->disabled && !ts->suspended) {
218 /* Tell IRQ thread that it may poll the device. */
219 ts->stopped = false;
220 mb();
221 enable_irq(ts->spi->irq);
222 }
223}
224
225/* Must be called with ts->lock held */
226static void __ads7846_disable(struct ads7846 *ts)
227{
228 ads7846_stop(ts);
229 regulator_disable(ts->reg);
230
231 /*
232 * We know the chip's in low power mode since we always
233 * leave it that way after every request
234 */
235}
236
237/* Must be called with ts->lock held */
238static void __ads7846_enable(struct ads7846 *ts)
239{
240 int error;
241
242 error = regulator_enable(ts->reg);
243 if (error != 0)
244 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error);
245
246 ads7846_restart(ts);
247}
248
249static void ads7846_disable(struct ads7846 *ts)
250{
251 mutex_lock(&ts->lock);
252
253 if (!ts->disabled) {
254
255 if (!ts->suspended)
256 __ads7846_disable(ts);
257
258 ts->disabled = true;
259 }
260
261 mutex_unlock(&ts->lock);
262}
263
264static void ads7846_enable(struct ads7846 *ts)
265{
266 mutex_lock(&ts->lock);
267
268 if (ts->disabled) {
269
270 ts->disabled = false;
271
272 if (!ts->suspended)
273 __ads7846_enable(ts);
274 }
275
276 mutex_unlock(&ts->lock);
277}
278
279/*--------------------------------------------------------------------------*/
280
281/*
282 * Non-touchscreen sensors only use single-ended conversions.
283 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
284 * ads7846 lets that pin be unconnected, to use internal vREF.
285 */
286
287struct ser_req {
288 u8 ref_on;
289 u8 command;
290 u8 ref_off;
291 u16 scratch;
292 struct spi_message msg;
293 struct spi_transfer xfer[6];
294 /*
295 * DMA (thus cache coherency maintenance) requires the
296 * transfer buffers to live in their own cache lines.
297 */
298 __be16 sample ____cacheline_aligned;
299};
300
301struct ads7845_ser_req {
302 u8 command[3];
303 struct spi_message msg;
304 struct spi_transfer xfer[2];
305 /*
306 * DMA (thus cache coherency maintenance) requires the
307 * transfer buffers to live in their own cache lines.
308 */
309 u8 sample[3] ____cacheline_aligned;
310};
311
312static int ads7846_read12_ser(struct device *dev, unsigned command)
313{
314 struct spi_device *spi = to_spi_device(dev);
315 struct ads7846 *ts = dev_get_drvdata(dev);
316 struct ser_req *req;
317 int status;
318
319 req = kzalloc(sizeof *req, GFP_KERNEL);
320 if (!req)
321 return -ENOMEM;
322
323 spi_message_init(&req->msg);
324
325 /* maybe turn on internal vREF, and let it settle */
326 if (ts->use_internal) {
327 req->ref_on = REF_ON;
328 req->xfer[0].tx_buf = &req->ref_on;
329 req->xfer[0].len = 1;
330 spi_message_add_tail(&req->xfer[0], &req->msg);
331
332 req->xfer[1].rx_buf = &req->scratch;
333 req->xfer[1].len = 2;
334
335 /* for 1uF, settle for 800 usec; no cap, 100 usec. */
336 req->xfer[1].delay.value = ts->vref_delay_usecs;
337 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS;
338 spi_message_add_tail(&req->xfer[1], &req->msg);
339
340 /* Enable reference voltage */
341 command |= ADS_PD10_REF_ON;
342 }
343
344 /* Enable ADC in every case */
345 command |= ADS_PD10_ADC_ON;
346
347 /* take sample */
348 req->command = (u8) command;
349 req->xfer[2].tx_buf = &req->command;
350 req->xfer[2].len = 1;
351 spi_message_add_tail(&req->xfer[2], &req->msg);
352
353 req->xfer[3].rx_buf = &req->sample;
354 req->xfer[3].len = 2;
355 spi_message_add_tail(&req->xfer[3], &req->msg);
356
357 /* REVISIT: take a few more samples, and compare ... */
358
359 /* converter in low power mode & enable PENIRQ */
360 req->ref_off = PWRDOWN;
361 req->xfer[4].tx_buf = &req->ref_off;
362 req->xfer[4].len = 1;
363 spi_message_add_tail(&req->xfer[4], &req->msg);
364
365 req->xfer[5].rx_buf = &req->scratch;
366 req->xfer[5].len = 2;
367 CS_CHANGE(req->xfer[5]);
368 spi_message_add_tail(&req->xfer[5], &req->msg);
369
370 mutex_lock(&ts->lock);
371 ads7846_stop(ts);
372 status = spi_sync(spi, &req->msg);
373 ads7846_restart(ts);
374 mutex_unlock(&ts->lock);
375
376 if (status == 0) {
377 /* on-wire is a must-ignore bit, a BE12 value, then padding */
378 status = be16_to_cpu(req->sample);
379 status = status >> 3;
380 status &= 0x0fff;
381 }
382
383 kfree(req);
384 return status;
385}
386
387static int ads7845_read12_ser(struct device *dev, unsigned command)
388{
389 struct spi_device *spi = to_spi_device(dev);
390 struct ads7846 *ts = dev_get_drvdata(dev);
391 struct ads7845_ser_req *req;
392 int status;
393
394 req = kzalloc(sizeof *req, GFP_KERNEL);
395 if (!req)
396 return -ENOMEM;
397
398 spi_message_init(&req->msg);
399
400 req->command[0] = (u8) command;
401 req->xfer[0].tx_buf = req->command;
402 req->xfer[0].rx_buf = req->sample;
403 req->xfer[0].len = 3;
404 spi_message_add_tail(&req->xfer[0], &req->msg);
405
406 mutex_lock(&ts->lock);
407 ads7846_stop(ts);
408 status = spi_sync(spi, &req->msg);
409 ads7846_restart(ts);
410 mutex_unlock(&ts->lock);
411
412 if (status == 0) {
413 /* BE12 value, then padding */
414 status = be16_to_cpu(*((u16 *)&req->sample[1]));
415 status = status >> 3;
416 status &= 0x0fff;
417 }
418
419 kfree(req);
420 return status;
421}
422
423#if IS_ENABLED(CONFIG_HWMON)
424
425#define SHOW(name, var, adjust) static ssize_t \
426name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
427{ \
428 struct ads7846 *ts = dev_get_drvdata(dev); \
429 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \
430 READ_12BIT_SER(var)); \
431 if (v < 0) \
432 return v; \
433 return sprintf(buf, "%u\n", adjust(ts, v)); \
434} \
435static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
436
437
438/* Sysfs conventions report temperatures in millidegrees Celsius.
439 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
440 * accuracy scheme without calibration data. For now we won't try either;
441 * userspace sees raw sensor values, and must scale/calibrate appropriately.
442 */
443static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
444{
445 return v;
446}
447
448SHOW(temp0, temp0, null_adjust) /* temp1_input */
449SHOW(temp1, temp1, null_adjust) /* temp2_input */
450
451
452/* sysfs conventions report voltages in millivolts. We can convert voltages
453 * if we know vREF. userspace may need to scale vAUX to match the board's
454 * external resistors; we assume that vBATT only uses the internal ones.
455 */
456static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
457{
458 unsigned retval = v;
459
460 /* external resistors may scale vAUX into 0..vREF */
461 retval *= ts->vref_mv;
462 retval = retval >> 12;
463
464 return retval;
465}
466
467static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
468{
469 unsigned retval = vaux_adjust(ts, v);
470
471 /* ads7846 has a resistor ladder to scale this signal down */
472 if (ts->model == 7846)
473 retval *= 4;
474
475 return retval;
476}
477
478SHOW(in0_input, vaux, vaux_adjust)
479SHOW(in1_input, vbatt, vbatt_adjust)
480
481static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr,
482 int index)
483{
484 struct device *dev = container_of(kobj, struct device, kobj);
485 struct ads7846 *ts = dev_get_drvdata(dev);
486
487 if (ts->model == 7843 && index < 2) /* in0, in1 */
488 return 0;
489 if (ts->model == 7845 && index != 2) /* in0 */
490 return 0;
491
492 return attr->mode;
493}
494
495static struct attribute *ads7846_attributes[] = {
496 &dev_attr_temp0.attr, /* 0 */
497 &dev_attr_temp1.attr, /* 1 */
498 &dev_attr_in0_input.attr, /* 2 */
499 &dev_attr_in1_input.attr, /* 3 */
500 NULL,
501};
502
503static const struct attribute_group ads7846_attr_group = {
504 .attrs = ads7846_attributes,
505 .is_visible = ads7846_is_visible,
506};
507__ATTRIBUTE_GROUPS(ads7846_attr);
508
509static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
510{
511 /* hwmon sensors need a reference voltage */
512 switch (ts->model) {
513 case 7846:
514 if (!ts->vref_mv) {
515 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
516 ts->vref_mv = 2500;
517 ts->use_internal = true;
518 }
519 break;
520 case 7845:
521 case 7843:
522 if (!ts->vref_mv) {
523 dev_warn(&spi->dev,
524 "external vREF for ADS%d not specified\n",
525 ts->model);
526 return 0;
527 }
528 break;
529 }
530
531 ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias,
532 ts, ads7846_attr_groups);
533
534 return PTR_ERR_OR_ZERO(ts->hwmon);
535}
536
537static void ads784x_hwmon_unregister(struct spi_device *spi,
538 struct ads7846 *ts)
539{
540 if (ts->hwmon)
541 hwmon_device_unregister(ts->hwmon);
542}
543
544#else
545static inline int ads784x_hwmon_register(struct spi_device *spi,
546 struct ads7846 *ts)
547{
548 return 0;
549}
550
551static inline void ads784x_hwmon_unregister(struct spi_device *spi,
552 struct ads7846 *ts)
553{
554}
555#endif
556
557static ssize_t ads7846_pen_down_show(struct device *dev,
558 struct device_attribute *attr, char *buf)
559{
560 struct ads7846 *ts = dev_get_drvdata(dev);
561
562 return sprintf(buf, "%u\n", ts->pendown);
563}
564
565static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
566
567static ssize_t ads7846_disable_show(struct device *dev,
568 struct device_attribute *attr, char *buf)
569{
570 struct ads7846 *ts = dev_get_drvdata(dev);
571
572 return sprintf(buf, "%u\n", ts->disabled);
573}
574
575static ssize_t ads7846_disable_store(struct device *dev,
576 struct device_attribute *attr,
577 const char *buf, size_t count)
578{
579 struct ads7846 *ts = dev_get_drvdata(dev);
580 unsigned int i;
581 int err;
582
583 err = kstrtouint(buf, 10, &i);
584 if (err)
585 return err;
586
587 if (i)
588 ads7846_disable(ts);
589 else
590 ads7846_enable(ts);
591
592 return count;
593}
594
595static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
596
597static struct attribute *ads784x_attributes[] = {
598 &dev_attr_pen_down.attr,
599 &dev_attr_disable.attr,
600 NULL,
601};
602
603static const struct attribute_group ads784x_attr_group = {
604 .attrs = ads784x_attributes,
605};
606
607/*--------------------------------------------------------------------------*/
608
609static int get_pendown_state(struct ads7846 *ts)
610{
611 if (ts->get_pendown_state)
612 return ts->get_pendown_state();
613
614 return !gpio_get_value(ts->gpio_pendown);
615}
616
617static void null_wait_for_sync(void)
618{
619}
620
621static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
622{
623 struct ads7846 *ts = ads;
624
625 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
626 /* Start over collecting consistent readings. */
627 ts->read_rep = 0;
628 /*
629 * Repeat it, if this was the first read or the read
630 * wasn't consistent enough.
631 */
632 if (ts->read_cnt < ts->debounce_max) {
633 ts->last_read = *val;
634 ts->read_cnt++;
635 return ADS7846_FILTER_REPEAT;
636 } else {
637 /*
638 * Maximum number of debouncing reached and still
639 * not enough number of consistent readings. Abort
640 * the whole sample, repeat it in the next sampling
641 * period.
642 */
643 ts->read_cnt = 0;
644 return ADS7846_FILTER_IGNORE;
645 }
646 } else {
647 if (++ts->read_rep > ts->debounce_rep) {
648 /*
649 * Got a good reading for this coordinate,
650 * go for the next one.
651 */
652 ts->read_cnt = 0;
653 ts->read_rep = 0;
654 return ADS7846_FILTER_OK;
655 } else {
656 /* Read more values that are consistent. */
657 ts->read_cnt++;
658 return ADS7846_FILTER_REPEAT;
659 }
660 }
661}
662
663static int ads7846_no_filter(void *ads, int data_idx, int *val)
664{
665 return ADS7846_FILTER_OK;
666}
667
668static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
669{
670 int value;
671 struct spi_transfer *t =
672 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
673
674 if (ts->model == 7845) {
675 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1]));
676 } else {
677 /*
678 * adjust: on-wire is a must-ignore bit, a BE12 value, then
679 * padding; built from two 8 bit values written msb-first.
680 */
681 value = be16_to_cpup((__be16 *)t->rx_buf);
682 }
683
684 /* enforce ADC output is 12 bits width */
685 return (value >> 3) & 0xfff;
686}
687
688static void ads7846_update_value(struct spi_message *m, int val)
689{
690 struct spi_transfer *t =
691 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
692
693 *(u16 *)t->rx_buf = val;
694}
695
696static void ads7846_read_state(struct ads7846 *ts)
697{
698 struct ads7846_packet *packet = ts->packet;
699 struct spi_message *m;
700 int msg_idx = 0;
701 int val;
702 int action;
703 int error;
704
705 while (msg_idx < ts->msg_count) {
706
707 ts->wait_for_sync();
708
709 m = &ts->msg[msg_idx];
710 error = spi_sync(ts->spi, m);
711 if (error) {
712 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
713 packet->tc.ignore = true;
714 return;
715 }
716
717 /*
718 * Last message is power down request, no need to convert
719 * or filter the value.
720 */
721 if (msg_idx < ts->msg_count - 1) {
722
723 val = ads7846_get_value(ts, m);
724
725 action = ts->filter(ts->filter_data, msg_idx, &val);
726 switch (action) {
727 case ADS7846_FILTER_REPEAT:
728 continue;
729
730 case ADS7846_FILTER_IGNORE:
731 packet->tc.ignore = true;
732 msg_idx = ts->msg_count - 1;
733 continue;
734
735 case ADS7846_FILTER_OK:
736 ads7846_update_value(m, val);
737 packet->tc.ignore = false;
738 msg_idx++;
739 break;
740
741 default:
742 BUG();
743 }
744 } else {
745 msg_idx++;
746 }
747 }
748}
749
750static void ads7846_report_state(struct ads7846 *ts)
751{
752 struct ads7846_packet *packet = ts->packet;
753 unsigned int Rt;
754 u16 x, y, z1, z2;
755
756 /*
757 * ads7846_get_value() does in-place conversion (including byte swap)
758 * from on-the-wire format as part of debouncing to get stable
759 * readings.
760 */
761 if (ts->model == 7845) {
762 x = *(u16 *)packet->tc.x_buf;
763 y = *(u16 *)packet->tc.y_buf;
764 z1 = 0;
765 z2 = 0;
766 } else {
767 x = packet->tc.x;
768 y = packet->tc.y;
769 z1 = packet->tc.z1;
770 z2 = packet->tc.z2;
771 }
772
773 /* range filtering */
774 if (x == MAX_12BIT)
775 x = 0;
776
777 if (ts->model == 7843) {
778 Rt = ts->pressure_max / 2;
779 } else if (ts->model == 7845) {
780 if (get_pendown_state(ts))
781 Rt = ts->pressure_max / 2;
782 else
783 Rt = 0;
784 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
785 } else if (likely(x && z1)) {
786 /* compute touch pressure resistance using equation #2 */
787 Rt = z2;
788 Rt -= z1;
789 Rt *= x;
790 Rt *= ts->x_plate_ohms;
791 Rt /= z1;
792 Rt = (Rt + 2047) >> 12;
793 } else {
794 Rt = 0;
795 }
796
797 /*
798 * Sample found inconsistent by debouncing or pressure is beyond
799 * the maximum. Don't report it to user space, repeat at least
800 * once more the measurement
801 */
802 if (packet->tc.ignore || Rt > ts->pressure_max) {
803 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
804 packet->tc.ignore, Rt);
805 return;
806 }
807
808 /*
809 * Maybe check the pendown state before reporting. This discards
810 * false readings when the pen is lifted.
811 */
812 if (ts->penirq_recheck_delay_usecs) {
813 udelay(ts->penirq_recheck_delay_usecs);
814 if (!get_pendown_state(ts))
815 Rt = 0;
816 }
817
818 /*
819 * NOTE: We can't rely on the pressure to determine the pen down
820 * state, even this controller has a pressure sensor. The pressure
821 * value can fluctuate for quite a while after lifting the pen and
822 * in some cases may not even settle at the expected value.
823 *
824 * The only safe way to check for the pen up condition is in the
825 * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
826 */
827 if (Rt) {
828 struct input_dev *input = ts->input;
829
830 if (!ts->pendown) {
831 input_report_key(input, BTN_TOUCH, 1);
832 ts->pendown = true;
833 dev_vdbg(&ts->spi->dev, "DOWN\n");
834 }
835
836 touchscreen_report_pos(input, &ts->core_prop, x, y, false);
837 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
838
839 input_sync(input);
840 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
841 }
842}
843
844static irqreturn_t ads7846_hard_irq(int irq, void *handle)
845{
846 struct ads7846 *ts = handle;
847
848 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
849}
850
851
852static irqreturn_t ads7846_irq(int irq, void *handle)
853{
854 struct ads7846 *ts = handle;
855
856 /* Start with a small delay before checking pendown state */
857 msleep(TS_POLL_DELAY);
858
859 while (!ts->stopped && get_pendown_state(ts)) {
860
861 /* pen is down, continue with the measurement */
862 ads7846_read_state(ts);
863
864 if (!ts->stopped)
865 ads7846_report_state(ts);
866
867 wait_event_timeout(ts->wait, ts->stopped,
868 msecs_to_jiffies(TS_POLL_PERIOD));
869 }
870
871 if (ts->pendown && !ts->stopped) {
872 struct input_dev *input = ts->input;
873
874 input_report_key(input, BTN_TOUCH, 0);
875 input_report_abs(input, ABS_PRESSURE, 0);
876 input_sync(input);
877
878 ts->pendown = false;
879 dev_vdbg(&ts->spi->dev, "UP\n");
880 }
881
882 return IRQ_HANDLED;
883}
884
885static int __maybe_unused ads7846_suspend(struct device *dev)
886{
887 struct ads7846 *ts = dev_get_drvdata(dev);
888
889 mutex_lock(&ts->lock);
890
891 if (!ts->suspended) {
892
893 if (!ts->disabled)
894 __ads7846_disable(ts);
895
896 if (device_may_wakeup(&ts->spi->dev))
897 enable_irq_wake(ts->spi->irq);
898
899 ts->suspended = true;
900 }
901
902 mutex_unlock(&ts->lock);
903
904 return 0;
905}
906
907static int __maybe_unused ads7846_resume(struct device *dev)
908{
909 struct ads7846 *ts = dev_get_drvdata(dev);
910
911 mutex_lock(&ts->lock);
912
913 if (ts->suspended) {
914
915 ts->suspended = false;
916
917 if (device_may_wakeup(&ts->spi->dev))
918 disable_irq_wake(ts->spi->irq);
919
920 if (!ts->disabled)
921 __ads7846_enable(ts);
922 }
923
924 mutex_unlock(&ts->lock);
925
926 return 0;
927}
928
929static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
930
931static int ads7846_setup_pendown(struct spi_device *spi,
932 struct ads7846 *ts,
933 const struct ads7846_platform_data *pdata)
934{
935 int err;
936
937 /*
938 * REVISIT when the irq can be triggered active-low, or if for some
939 * reason the touchscreen isn't hooked up, we don't need to access
940 * the pendown state.
941 */
942
943 if (pdata->get_pendown_state) {
944 ts->get_pendown_state = pdata->get_pendown_state;
945 } else if (gpio_is_valid(pdata->gpio_pendown)) {
946
947 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
948 "ads7846_pendown");
949 if (err) {
950 dev_err(&spi->dev,
951 "failed to request/setup pendown GPIO%d: %d\n",
952 pdata->gpio_pendown, err);
953 return err;
954 }
955
956 ts->gpio_pendown = pdata->gpio_pendown;
957
958 if (pdata->gpio_pendown_debounce)
959 gpio_set_debounce(pdata->gpio_pendown,
960 pdata->gpio_pendown_debounce);
961 } else {
962 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
963 return -EINVAL;
964 }
965
966 return 0;
967}
968
969/*
970 * Set up the transfers to read touchscreen state; this assumes we
971 * use formula #2 for pressure, not #3.
972 */
973static void ads7846_setup_spi_msg(struct ads7846 *ts,
974 const struct ads7846_platform_data *pdata)
975{
976 struct spi_message *m = &ts->msg[0];
977 struct spi_transfer *x = ts->xfer;
978 struct ads7846_packet *packet = ts->packet;
979 int vref = pdata->keep_vref_on;
980
981 if (ts->model == 7873) {
982 /*
983 * The AD7873 is almost identical to the ADS7846
984 * keep VREF off during differential/ratiometric
985 * conversion modes.
986 */
987 ts->model = 7846;
988 vref = 0;
989 }
990
991 ts->msg_count = 1;
992 spi_message_init(m);
993 m->context = ts;
994
995 if (ts->model == 7845) {
996 packet->read_y_cmd[0] = READ_Y(vref);
997 packet->read_y_cmd[1] = 0;
998 packet->read_y_cmd[2] = 0;
999 x->tx_buf = &packet->read_y_cmd[0];
1000 x->rx_buf = &packet->tc.y_buf[0];
1001 x->len = 3;
1002 spi_message_add_tail(x, m);
1003 } else {
1004 /* y- still on; turn on only y+ (and ADC) */
1005 packet->read_y = READ_Y(vref);
1006 x->tx_buf = &packet->read_y;
1007 x->len = 1;
1008 spi_message_add_tail(x, m);
1009
1010 x++;
1011 x->rx_buf = &packet->tc.y;
1012 x->len = 2;
1013 spi_message_add_tail(x, m);
1014 }
1015
1016 /*
1017 * The first sample after switching drivers can be low quality;
1018 * optionally discard it, using a second one after the signals
1019 * have had enough time to stabilize.
1020 */
1021 if (pdata->settle_delay_usecs) {
1022 x->delay.value = pdata->settle_delay_usecs;
1023 x->delay.unit = SPI_DELAY_UNIT_USECS;
1024
1025 x++;
1026 x->tx_buf = &packet->read_y;
1027 x->len = 1;
1028 spi_message_add_tail(x, m);
1029
1030 x++;
1031 x->rx_buf = &packet->tc.y;
1032 x->len = 2;
1033 spi_message_add_tail(x, m);
1034 }
1035
1036 ts->msg_count++;
1037 m++;
1038 spi_message_init(m);
1039 m->context = ts;
1040
1041 if (ts->model == 7845) {
1042 x++;
1043 packet->read_x_cmd[0] = READ_X(vref);
1044 packet->read_x_cmd[1] = 0;
1045 packet->read_x_cmd[2] = 0;
1046 x->tx_buf = &packet->read_x_cmd[0];
1047 x->rx_buf = &packet->tc.x_buf[0];
1048 x->len = 3;
1049 spi_message_add_tail(x, m);
1050 } else {
1051 /* turn y- off, x+ on, then leave in lowpower */
1052 x++;
1053 packet->read_x = READ_X(vref);
1054 x->tx_buf = &packet->read_x;
1055 x->len = 1;
1056 spi_message_add_tail(x, m);
1057
1058 x++;
1059 x->rx_buf = &packet->tc.x;
1060 x->len = 2;
1061 spi_message_add_tail(x, m);
1062 }
1063
1064 /* ... maybe discard first sample ... */
1065 if (pdata->settle_delay_usecs) {
1066 x->delay.value = pdata->settle_delay_usecs;
1067 x->delay.unit = SPI_DELAY_UNIT_USECS;
1068
1069 x++;
1070 x->tx_buf = &packet->read_x;
1071 x->len = 1;
1072 spi_message_add_tail(x, m);
1073
1074 x++;
1075 x->rx_buf = &packet->tc.x;
1076 x->len = 2;
1077 spi_message_add_tail(x, m);
1078 }
1079
1080 /* turn y+ off, x- on; we'll use formula #2 */
1081 if (ts->model == 7846) {
1082 ts->msg_count++;
1083 m++;
1084 spi_message_init(m);
1085 m->context = ts;
1086
1087 x++;
1088 packet->read_z1 = READ_Z1(vref);
1089 x->tx_buf = &packet->read_z1;
1090 x->len = 1;
1091 spi_message_add_tail(x, m);
1092
1093 x++;
1094 x->rx_buf = &packet->tc.z1;
1095 x->len = 2;
1096 spi_message_add_tail(x, m);
1097
1098 /* ... maybe discard first sample ... */
1099 if (pdata->settle_delay_usecs) {
1100 x->delay.value = pdata->settle_delay_usecs;
1101 x->delay.unit = SPI_DELAY_UNIT_USECS;
1102
1103 x++;
1104 x->tx_buf = &packet->read_z1;
1105 x->len = 1;
1106 spi_message_add_tail(x, m);
1107
1108 x++;
1109 x->rx_buf = &packet->tc.z1;
1110 x->len = 2;
1111 spi_message_add_tail(x, m);
1112 }
1113
1114 ts->msg_count++;
1115 m++;
1116 spi_message_init(m);
1117 m->context = ts;
1118
1119 x++;
1120 packet->read_z2 = READ_Z2(vref);
1121 x->tx_buf = &packet->read_z2;
1122 x->len = 1;
1123 spi_message_add_tail(x, m);
1124
1125 x++;
1126 x->rx_buf = &packet->tc.z2;
1127 x->len = 2;
1128 spi_message_add_tail(x, m);
1129
1130 /* ... maybe discard first sample ... */
1131 if (pdata->settle_delay_usecs) {
1132 x->delay.value = pdata->settle_delay_usecs;
1133 x->delay.unit = SPI_DELAY_UNIT_USECS;
1134
1135 x++;
1136 x->tx_buf = &packet->read_z2;
1137 x->len = 1;
1138 spi_message_add_tail(x, m);
1139
1140 x++;
1141 x->rx_buf = &packet->tc.z2;
1142 x->len = 2;
1143 spi_message_add_tail(x, m);
1144 }
1145 }
1146
1147 /* power down */
1148 ts->msg_count++;
1149 m++;
1150 spi_message_init(m);
1151 m->context = ts;
1152
1153 if (ts->model == 7845) {
1154 x++;
1155 packet->pwrdown_cmd[0] = PWRDOWN;
1156 packet->pwrdown_cmd[1] = 0;
1157 packet->pwrdown_cmd[2] = 0;
1158 x->tx_buf = &packet->pwrdown_cmd[0];
1159 x->len = 3;
1160 } else {
1161 x++;
1162 packet->pwrdown = PWRDOWN;
1163 x->tx_buf = &packet->pwrdown;
1164 x->len = 1;
1165 spi_message_add_tail(x, m);
1166
1167 x++;
1168 x->rx_buf = &packet->dummy;
1169 x->len = 2;
1170 }
1171
1172 CS_CHANGE(*x);
1173 spi_message_add_tail(x, m);
1174}
1175
1176#ifdef CONFIG_OF
1177static const struct of_device_id ads7846_dt_ids[] = {
1178 { .compatible = "ti,tsc2046", .data = (void *) 7846 },
1179 { .compatible = "ti,ads7843", .data = (void *) 7843 },
1180 { .compatible = "ti,ads7845", .data = (void *) 7845 },
1181 { .compatible = "ti,ads7846", .data = (void *) 7846 },
1182 { .compatible = "ti,ads7873", .data = (void *) 7873 },
1183 { }
1184};
1185MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1186
1187static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1188{
1189 struct ads7846_platform_data *pdata;
1190 struct device_node *node = dev->of_node;
1191 const struct of_device_id *match;
1192 u32 value;
1193
1194 if (!node) {
1195 dev_err(dev, "Device does not have associated DT data\n");
1196 return ERR_PTR(-EINVAL);
1197 }
1198
1199 match = of_match_device(ads7846_dt_ids, dev);
1200 if (!match) {
1201 dev_err(dev, "Unknown device model\n");
1202 return ERR_PTR(-EINVAL);
1203 }
1204
1205 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1206 if (!pdata)
1207 return ERR_PTR(-ENOMEM);
1208
1209 pdata->model = (unsigned long)match->data;
1210
1211 of_property_read_u16(node, "ti,vref-delay-usecs",
1212 &pdata->vref_delay_usecs);
1213 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
1214 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
1215
1216 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
1217
1218 of_property_read_u16(node, "ti,settle-delay-usec",
1219 &pdata->settle_delay_usecs);
1220 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
1221 &pdata->penirq_recheck_delay_usecs);
1222
1223 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1224 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1225
1226 of_property_read_u16(node, "ti,x-min", &pdata->x_min);
1227 of_property_read_u16(node, "ti,y-min", &pdata->y_min);
1228 of_property_read_u16(node, "ti,x-max", &pdata->x_max);
1229 of_property_read_u16(node, "ti,y-max", &pdata->y_max);
1230
1231 /*
1232 * touchscreen-max-pressure gets parsed during
1233 * touchscreen_parse_properties()
1234 */
1235 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1236 if (!of_property_read_u32(node, "touchscreen-min-pressure", &value))
1237 pdata->pressure_min = (u16) value;
1238 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1239
1240 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1241 if (!of_property_read_u32(node, "touchscreen-average-samples", &value))
1242 pdata->debounce_max = (u16) value;
1243 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1244 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1245
1246 of_property_read_u32(node, "ti,pendown-gpio-debounce",
1247 &pdata->gpio_pendown_debounce);
1248
1249 pdata->wakeup = of_property_read_bool(node, "wakeup-source") ||
1250 of_property_read_bool(node, "linux,wakeup");
1251
1252 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1253
1254 return pdata;
1255}
1256#else
1257static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1258{
1259 dev_err(dev, "no platform data defined\n");
1260 return ERR_PTR(-EINVAL);
1261}
1262#endif
1263
1264static int ads7846_probe(struct spi_device *spi)
1265{
1266 const struct ads7846_platform_data *pdata;
1267 struct ads7846 *ts;
1268 struct ads7846_packet *packet;
1269 struct input_dev *input_dev;
1270 unsigned long irq_flags;
1271 int err;
1272
1273 if (!spi->irq) {
1274 dev_dbg(&spi->dev, "no IRQ?\n");
1275 return -EINVAL;
1276 }
1277
1278 /* don't exceed max specified sample rate */
1279 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1280 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1281 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1282 return -EINVAL;
1283 }
1284
1285 /*
1286 * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1287 * that even if the hardware can do that, the SPI controller driver
1288 * may not. So we stick to very-portable 8 bit words, both RX and TX.
1289 */
1290 spi->bits_per_word = 8;
1291 spi->mode = SPI_MODE_0;
1292 err = spi_setup(spi);
1293 if (err < 0)
1294 return err;
1295
1296 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1297 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1298 input_dev = input_allocate_device();
1299 if (!ts || !packet || !input_dev) {
1300 err = -ENOMEM;
1301 goto err_free_mem;
1302 }
1303
1304 spi_set_drvdata(spi, ts);
1305
1306 ts->packet = packet;
1307 ts->spi = spi;
1308 ts->input = input_dev;
1309
1310 mutex_init(&ts->lock);
1311 init_waitqueue_head(&ts->wait);
1312
1313 pdata = dev_get_platdata(&spi->dev);
1314 if (!pdata) {
1315 pdata = ads7846_probe_dt(&spi->dev);
1316 if (IS_ERR(pdata)) {
1317 err = PTR_ERR(pdata);
1318 goto err_free_mem;
1319 }
1320 }
1321
1322 ts->model = pdata->model ? : 7846;
1323 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1324 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1325 ts->vref_mv = pdata->vref_mv;
1326
1327 if (pdata->filter != NULL) {
1328 if (pdata->filter_init != NULL) {
1329 err = pdata->filter_init(pdata, &ts->filter_data);
1330 if (err < 0)
1331 goto err_free_mem;
1332 }
1333 ts->filter = pdata->filter;
1334 ts->filter_cleanup = pdata->filter_cleanup;
1335 } else if (pdata->debounce_max) {
1336 ts->debounce_max = pdata->debounce_max;
1337 if (ts->debounce_max < 2)
1338 ts->debounce_max = 2;
1339 ts->debounce_tol = pdata->debounce_tol;
1340 ts->debounce_rep = pdata->debounce_rep;
1341 ts->filter = ads7846_debounce_filter;
1342 ts->filter_data = ts;
1343 } else {
1344 ts->filter = ads7846_no_filter;
1345 }
1346
1347 err = ads7846_setup_pendown(spi, ts, pdata);
1348 if (err)
1349 goto err_cleanup_filter;
1350
1351 if (pdata->penirq_recheck_delay_usecs)
1352 ts->penirq_recheck_delay_usecs =
1353 pdata->penirq_recheck_delay_usecs;
1354
1355 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1356
1357 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1358 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1359
1360 input_dev->name = ts->name;
1361 input_dev->phys = ts->phys;
1362 input_dev->dev.parent = &spi->dev;
1363
1364 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1365 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1366 input_set_abs_params(input_dev, ABS_X,
1367 pdata->x_min ? : 0,
1368 pdata->x_max ? : MAX_12BIT,
1369 0, 0);
1370 input_set_abs_params(input_dev, ABS_Y,
1371 pdata->y_min ? : 0,
1372 pdata->y_max ? : MAX_12BIT,
1373 0, 0);
1374 input_set_abs_params(input_dev, ABS_PRESSURE,
1375 pdata->pressure_min, pdata->pressure_max, 0, 0);
1376
1377 /*
1378 * Parse common framework properties. Must be done here to ensure the
1379 * correct behaviour in case of using the legacy vendor bindings. The
1380 * general binding value overrides the vendor specific one.
1381 */
1382 touchscreen_parse_properties(ts->input, false, &ts->core_prop);
1383 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0;
1384
1385 /*
1386 * Check if legacy ti,swap-xy binding is used instead of
1387 * touchscreen-swapped-x-y
1388 */
1389 if (!ts->core_prop.swap_x_y && pdata->swap_xy) {
1390 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]);
1391 ts->core_prop.swap_x_y = true;
1392 }
1393
1394 ads7846_setup_spi_msg(ts, pdata);
1395
1396 ts->reg = regulator_get(&spi->dev, "vcc");
1397 if (IS_ERR(ts->reg)) {
1398 err = PTR_ERR(ts->reg);
1399 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1400 goto err_free_gpio;
1401 }
1402
1403 err = regulator_enable(ts->reg);
1404 if (err) {
1405 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1406 goto err_put_regulator;
1407 }
1408
1409 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1410 irq_flags |= IRQF_ONESHOT;
1411
1412 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1413 irq_flags, spi->dev.driver->name, ts);
1414 if (err && !pdata->irq_flags) {
1415 dev_info(&spi->dev,
1416 "trying pin change workaround on irq %d\n", spi->irq);
1417 irq_flags |= IRQF_TRIGGER_RISING;
1418 err = request_threaded_irq(spi->irq,
1419 ads7846_hard_irq, ads7846_irq,
1420 irq_flags, spi->dev.driver->name, ts);
1421 }
1422
1423 if (err) {
1424 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1425 goto err_disable_regulator;
1426 }
1427
1428 err = ads784x_hwmon_register(spi, ts);
1429 if (err)
1430 goto err_free_irq;
1431
1432 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1433
1434 /*
1435 * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1436 * the touchscreen, in case it's not connected.
1437 */
1438 if (ts->model == 7845)
1439 ads7845_read12_ser(&spi->dev, PWRDOWN);
1440 else
1441 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1442
1443 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1444 if (err)
1445 goto err_remove_hwmon;
1446
1447 err = input_register_device(input_dev);
1448 if (err)
1449 goto err_remove_attr_group;
1450
1451 device_init_wakeup(&spi->dev, pdata->wakeup);
1452
1453 /*
1454 * If device does not carry platform data we must have allocated it
1455 * when parsing DT data.
1456 */
1457 if (!dev_get_platdata(&spi->dev))
1458 devm_kfree(&spi->dev, (void *)pdata);
1459
1460 return 0;
1461
1462 err_remove_attr_group:
1463 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1464 err_remove_hwmon:
1465 ads784x_hwmon_unregister(spi, ts);
1466 err_free_irq:
1467 free_irq(spi->irq, ts);
1468 err_disable_regulator:
1469 regulator_disable(ts->reg);
1470 err_put_regulator:
1471 regulator_put(ts->reg);
1472 err_free_gpio:
1473 if (!ts->get_pendown_state)
1474 gpio_free(ts->gpio_pendown);
1475 err_cleanup_filter:
1476 if (ts->filter_cleanup)
1477 ts->filter_cleanup(ts->filter_data);
1478 err_free_mem:
1479 input_free_device(input_dev);
1480 kfree(packet);
1481 kfree(ts);
1482 return err;
1483}
1484
1485static int ads7846_remove(struct spi_device *spi)
1486{
1487 struct ads7846 *ts = spi_get_drvdata(spi);
1488
1489 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1490
1491 ads7846_disable(ts);
1492 free_irq(ts->spi->irq, ts);
1493
1494 input_unregister_device(ts->input);
1495
1496 ads784x_hwmon_unregister(spi, ts);
1497
1498 regulator_put(ts->reg);
1499
1500 if (!ts->get_pendown_state) {
1501 /*
1502 * If we are not using specialized pendown method we must
1503 * have been relying on gpio we set up ourselves.
1504 */
1505 gpio_free(ts->gpio_pendown);
1506 }
1507
1508 if (ts->filter_cleanup)
1509 ts->filter_cleanup(ts->filter_data);
1510
1511 kfree(ts->packet);
1512 kfree(ts);
1513
1514 dev_dbg(&spi->dev, "unregistered touchscreen\n");
1515
1516 return 0;
1517}
1518
1519static struct spi_driver ads7846_driver = {
1520 .driver = {
1521 .name = "ads7846",
1522 .pm = &ads7846_pm,
1523 .of_match_table = of_match_ptr(ads7846_dt_ids),
1524 },
1525 .probe = ads7846_probe,
1526 .remove = ads7846_remove,
1527};
1528
1529module_spi_driver(ads7846_driver);
1530
1531MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1532MODULE_LICENSE("GPL");
1533MODULE_ALIAS("spi:ads7846");