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 const 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
533 return PTR_ERR_OR_ZERO(ts->hwmon);
534}
535
536static void ads784x_hwmon_unregister(struct spi_device *spi,
537 struct ads7846 *ts)
538{
539 if (ts->hwmon)
540 hwmon_device_unregister(ts->hwmon);
541}
542
543#else
544static inline int ads784x_hwmon_register(struct spi_device *spi,
545 struct ads7846 *ts)
546{
547 return 0;
548}
549
550static inline void ads784x_hwmon_unregister(struct spi_device *spi,
551 struct ads7846 *ts)
552{
553}
554#endif
555
556static ssize_t ads7846_pen_down_show(struct device *dev,
557 struct device_attribute *attr, char *buf)
558{
559 struct ads7846 *ts = dev_get_drvdata(dev);
560
561 return sprintf(buf, "%u\n", ts->pendown);
562}
563
564static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
565
566static ssize_t ads7846_disable_show(struct device *dev,
567 struct device_attribute *attr, char *buf)
568{
569 struct ads7846 *ts = dev_get_drvdata(dev);
570
571 return sprintf(buf, "%u\n", ts->disabled);
572}
573
574static ssize_t ads7846_disable_store(struct device *dev,
575 struct device_attribute *attr,
576 const char *buf, size_t count)
577{
578 struct ads7846 *ts = dev_get_drvdata(dev);
579 unsigned int i;
580 int err;
581
582 err = kstrtouint(buf, 10, &i);
583 if (err)
584 return err;
585
586 if (i)
587 ads7846_disable(ts);
588 else
589 ads7846_enable(ts);
590
591 return count;
592}
593
594static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
595
596static struct attribute *ads784x_attributes[] = {
597 &dev_attr_pen_down.attr,
598 &dev_attr_disable.attr,
599 NULL,
600};
601
602static const struct attribute_group ads784x_attr_group = {
603 .attrs = ads784x_attributes,
604};
605
606/*--------------------------------------------------------------------------*/
607
608static int get_pendown_state(struct ads7846 *ts)
609{
610 if (ts->get_pendown_state)
611 return ts->get_pendown_state();
612
613 return !gpio_get_value(ts->gpio_pendown);
614}
615
616static void null_wait_for_sync(void)
617{
618}
619
620static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
621{
622 struct ads7846 *ts = ads;
623
624 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
625 /* Start over collecting consistent readings. */
626 ts->read_rep = 0;
627 /*
628 * Repeat it, if this was the first read or the read
629 * wasn't consistent enough.
630 */
631 if (ts->read_cnt < ts->debounce_max) {
632 ts->last_read = *val;
633 ts->read_cnt++;
634 return ADS7846_FILTER_REPEAT;
635 } else {
636 /*
637 * Maximum number of debouncing reached and still
638 * not enough number of consistent readings. Abort
639 * the whole sample, repeat it in the next sampling
640 * period.
641 */
642 ts->read_cnt = 0;
643 return ADS7846_FILTER_IGNORE;
644 }
645 } else {
646 if (++ts->read_rep > ts->debounce_rep) {
647 /*
648 * Got a good reading for this coordinate,
649 * go for the next one.
650 */
651 ts->read_cnt = 0;
652 ts->read_rep = 0;
653 return ADS7846_FILTER_OK;
654 } else {
655 /* Read more values that are consistent. */
656 ts->read_cnt++;
657 return ADS7846_FILTER_REPEAT;
658 }
659 }
660}
661
662static int ads7846_no_filter(void *ads, int data_idx, int *val)
663{
664 return ADS7846_FILTER_OK;
665}
666
667static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
668{
669 int value;
670 struct spi_transfer *t =
671 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
672
673 if (ts->model == 7845) {
674 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1]));
675 } else {
676 /*
677 * adjust: on-wire is a must-ignore bit, a BE12 value, then
678 * padding; built from two 8 bit values written msb-first.
679 */
680 value = be16_to_cpup((__be16 *)t->rx_buf);
681 }
682
683 /* enforce ADC output is 12 bits width */
684 return (value >> 3) & 0xfff;
685}
686
687static void ads7846_update_value(struct spi_message *m, int val)
688{
689 struct spi_transfer *t =
690 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
691
692 *(u16 *)t->rx_buf = val;
693}
694
695static void ads7846_read_state(struct ads7846 *ts)
696{
697 struct ads7846_packet *packet = ts->packet;
698 struct spi_message *m;
699 int msg_idx = 0;
700 int val;
701 int action;
702 int error;
703
704 while (msg_idx < ts->msg_count) {
705
706 ts->wait_for_sync();
707
708 m = &ts->msg[msg_idx];
709 error = spi_sync(ts->spi, m);
710 if (error) {
711 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
712 packet->tc.ignore = true;
713 return;
714 }
715
716 /*
717 * Last message is power down request, no need to convert
718 * or filter the value.
719 */
720 if (msg_idx < ts->msg_count - 1) {
721
722 val = ads7846_get_value(ts, m);
723
724 action = ts->filter(ts->filter_data, msg_idx, &val);
725 switch (action) {
726 case ADS7846_FILTER_REPEAT:
727 continue;
728
729 case ADS7846_FILTER_IGNORE:
730 packet->tc.ignore = true;
731 msg_idx = ts->msg_count - 1;
732 continue;
733
734 case ADS7846_FILTER_OK:
735 ads7846_update_value(m, val);
736 packet->tc.ignore = false;
737 msg_idx++;
738 break;
739
740 default:
741 BUG();
742 }
743 } else {
744 msg_idx++;
745 }
746 }
747}
748
749static void ads7846_report_state(struct ads7846 *ts)
750{
751 struct ads7846_packet *packet = ts->packet;
752 unsigned int Rt;
753 u16 x, y, z1, z2;
754
755 /*
756 * ads7846_get_value() does in-place conversion (including byte swap)
757 * from on-the-wire format as part of debouncing to get stable
758 * readings.
759 */
760 if (ts->model == 7845) {
761 x = *(u16 *)packet->tc.x_buf;
762 y = *(u16 *)packet->tc.y_buf;
763 z1 = 0;
764 z2 = 0;
765 } else {
766 x = packet->tc.x;
767 y = packet->tc.y;
768 z1 = packet->tc.z1;
769 z2 = packet->tc.z2;
770 }
771
772 /* range filtering */
773 if (x == MAX_12BIT)
774 x = 0;
775
776 if (ts->model == 7843) {
777 Rt = ts->pressure_max / 2;
778 } else if (ts->model == 7845) {
779 if (get_pendown_state(ts))
780 Rt = ts->pressure_max / 2;
781 else
782 Rt = 0;
783 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
784 } else if (likely(x && z1)) {
785 /* compute touch pressure resistance using equation #2 */
786 Rt = z2;
787 Rt -= z1;
788 Rt *= x;
789 Rt *= ts->x_plate_ohms;
790 Rt /= z1;
791 Rt = (Rt + 2047) >> 12;
792 } else {
793 Rt = 0;
794 }
795
796 /*
797 * Sample found inconsistent by debouncing or pressure is beyond
798 * the maximum. Don't report it to user space, repeat at least
799 * once more the measurement
800 */
801 if (packet->tc.ignore || Rt > ts->pressure_max) {
802 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
803 packet->tc.ignore, Rt);
804 return;
805 }
806
807 /*
808 * Maybe check the pendown state before reporting. This discards
809 * false readings when the pen is lifted.
810 */
811 if (ts->penirq_recheck_delay_usecs) {
812 udelay(ts->penirq_recheck_delay_usecs);
813 if (!get_pendown_state(ts))
814 Rt = 0;
815 }
816
817 /*
818 * NOTE: We can't rely on the pressure to determine the pen down
819 * state, even this controller has a pressure sensor. The pressure
820 * value can fluctuate for quite a while after lifting the pen and
821 * in some cases may not even settle at the expected value.
822 *
823 * The only safe way to check for the pen up condition is in the
824 * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
825 */
826 if (Rt) {
827 struct input_dev *input = ts->input;
828
829 if (ts->swap_xy)
830 swap(x, y);
831
832 if (!ts->pendown) {
833 input_report_key(input, BTN_TOUCH, 1);
834 ts->pendown = true;
835 dev_vdbg(&ts->spi->dev, "DOWN\n");
836 }
837
838 input_report_abs(input, ABS_X, x);
839 input_report_abs(input, ABS_Y, y);
840 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
841
842 input_sync(input);
843 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
844 }
845}
846
847static irqreturn_t ads7846_hard_irq(int irq, void *handle)
848{
849 struct ads7846 *ts = handle;
850
851 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
852}
853
854
855static irqreturn_t ads7846_irq(int irq, void *handle)
856{
857 struct ads7846 *ts = handle;
858
859 /* Start with a small delay before checking pendown state */
860 msleep(TS_POLL_DELAY);
861
862 while (!ts->stopped && get_pendown_state(ts)) {
863
864 /* pen is down, continue with the measurement */
865 ads7846_read_state(ts);
866
867 if (!ts->stopped)
868 ads7846_report_state(ts);
869
870 wait_event_timeout(ts->wait, ts->stopped,
871 msecs_to_jiffies(TS_POLL_PERIOD));
872 }
873
874 if (ts->pendown && !ts->stopped) {
875 struct input_dev *input = ts->input;
876
877 input_report_key(input, BTN_TOUCH, 0);
878 input_report_abs(input, ABS_PRESSURE, 0);
879 input_sync(input);
880
881 ts->pendown = false;
882 dev_vdbg(&ts->spi->dev, "UP\n");
883 }
884
885 return IRQ_HANDLED;
886}
887
888static int __maybe_unused ads7846_suspend(struct device *dev)
889{
890 struct ads7846 *ts = dev_get_drvdata(dev);
891
892 mutex_lock(&ts->lock);
893
894 if (!ts->suspended) {
895
896 if (!ts->disabled)
897 __ads7846_disable(ts);
898
899 if (device_may_wakeup(&ts->spi->dev))
900 enable_irq_wake(ts->spi->irq);
901
902 ts->suspended = true;
903 }
904
905 mutex_unlock(&ts->lock);
906
907 return 0;
908}
909
910static int __maybe_unused ads7846_resume(struct device *dev)
911{
912 struct ads7846 *ts = dev_get_drvdata(dev);
913
914 mutex_lock(&ts->lock);
915
916 if (ts->suspended) {
917
918 ts->suspended = false;
919
920 if (device_may_wakeup(&ts->spi->dev))
921 disable_irq_wake(ts->spi->irq);
922
923 if (!ts->disabled)
924 __ads7846_enable(ts);
925 }
926
927 mutex_unlock(&ts->lock);
928
929 return 0;
930}
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, "wakeup-source") ||
1240 of_property_read_bool(node, "linux,wakeup");
1241
1242 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1243
1244 return pdata;
1245}
1246#else
1247static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1248{
1249 dev_err(dev, "no platform data defined\n");
1250 return ERR_PTR(-EINVAL);
1251}
1252#endif
1253
1254static int ads7846_probe(struct spi_device *spi)
1255{
1256 const struct ads7846_platform_data *pdata;
1257 struct ads7846 *ts;
1258 struct ads7846_packet *packet;
1259 struct input_dev *input_dev;
1260 unsigned long irq_flags;
1261 int err;
1262
1263 if (!spi->irq) {
1264 dev_dbg(&spi->dev, "no IRQ?\n");
1265 return -EINVAL;
1266 }
1267
1268 /* don't exceed max specified sample rate */
1269 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1270 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1271 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1272 return -EINVAL;
1273 }
1274
1275 /*
1276 * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1277 * that even if the hardware can do that, the SPI controller driver
1278 * may not. So we stick to very-portable 8 bit words, both RX and TX.
1279 */
1280 spi->bits_per_word = 8;
1281 spi->mode = SPI_MODE_0;
1282 err = spi_setup(spi);
1283 if (err < 0)
1284 return err;
1285
1286 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1287 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1288 input_dev = input_allocate_device();
1289 if (!ts || !packet || !input_dev) {
1290 err = -ENOMEM;
1291 goto err_free_mem;
1292 }
1293
1294 spi_set_drvdata(spi, ts);
1295
1296 ts->packet = packet;
1297 ts->spi = spi;
1298 ts->input = input_dev;
1299
1300 mutex_init(&ts->lock);
1301 init_waitqueue_head(&ts->wait);
1302
1303 pdata = dev_get_platdata(&spi->dev);
1304 if (!pdata) {
1305 pdata = ads7846_probe_dt(&spi->dev);
1306 if (IS_ERR(pdata)) {
1307 err = PTR_ERR(pdata);
1308 goto err_free_mem;
1309 }
1310 }
1311
1312 ts->model = pdata->model ? : 7846;
1313 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1314 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1315 ts->pressure_max = pdata->pressure_max ? : ~0;
1316
1317 ts->vref_mv = pdata->vref_mv;
1318 ts->swap_xy = pdata->swap_xy;
1319
1320 if (pdata->filter != NULL) {
1321 if (pdata->filter_init != NULL) {
1322 err = pdata->filter_init(pdata, &ts->filter_data);
1323 if (err < 0)
1324 goto err_free_mem;
1325 }
1326 ts->filter = pdata->filter;
1327 ts->filter_cleanup = pdata->filter_cleanup;
1328 } else if (pdata->debounce_max) {
1329 ts->debounce_max = pdata->debounce_max;
1330 if (ts->debounce_max < 2)
1331 ts->debounce_max = 2;
1332 ts->debounce_tol = pdata->debounce_tol;
1333 ts->debounce_rep = pdata->debounce_rep;
1334 ts->filter = ads7846_debounce_filter;
1335 ts->filter_data = ts;
1336 } else {
1337 ts->filter = ads7846_no_filter;
1338 }
1339
1340 err = ads7846_setup_pendown(spi, ts, pdata);
1341 if (err)
1342 goto err_cleanup_filter;
1343
1344 if (pdata->penirq_recheck_delay_usecs)
1345 ts->penirq_recheck_delay_usecs =
1346 pdata->penirq_recheck_delay_usecs;
1347
1348 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1349
1350 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1351 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1352
1353 input_dev->name = ts->name;
1354 input_dev->phys = ts->phys;
1355 input_dev->dev.parent = &spi->dev;
1356
1357 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1358 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1359 input_set_abs_params(input_dev, ABS_X,
1360 pdata->x_min ? : 0,
1361 pdata->x_max ? : MAX_12BIT,
1362 0, 0);
1363 input_set_abs_params(input_dev, ABS_Y,
1364 pdata->y_min ? : 0,
1365 pdata->y_max ? : MAX_12BIT,
1366 0, 0);
1367 input_set_abs_params(input_dev, ABS_PRESSURE,
1368 pdata->pressure_min, pdata->pressure_max, 0, 0);
1369
1370 ads7846_setup_spi_msg(ts, pdata);
1371
1372 ts->reg = regulator_get(&spi->dev, "vcc");
1373 if (IS_ERR(ts->reg)) {
1374 err = PTR_ERR(ts->reg);
1375 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1376 goto err_free_gpio;
1377 }
1378
1379 err = regulator_enable(ts->reg);
1380 if (err) {
1381 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1382 goto err_put_regulator;
1383 }
1384
1385 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1386 irq_flags |= IRQF_ONESHOT;
1387
1388 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1389 irq_flags, spi->dev.driver->name, ts);
1390 if (err && !pdata->irq_flags) {
1391 dev_info(&spi->dev,
1392 "trying pin change workaround on irq %d\n", spi->irq);
1393 irq_flags |= IRQF_TRIGGER_RISING;
1394 err = request_threaded_irq(spi->irq,
1395 ads7846_hard_irq, ads7846_irq,
1396 irq_flags, spi->dev.driver->name, ts);
1397 }
1398
1399 if (err) {
1400 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1401 goto err_disable_regulator;
1402 }
1403
1404 err = ads784x_hwmon_register(spi, ts);
1405 if (err)
1406 goto err_free_irq;
1407
1408 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1409
1410 /*
1411 * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1412 * the touchscreen, in case it's not connected.
1413 */
1414 if (ts->model == 7845)
1415 ads7845_read12_ser(&spi->dev, PWRDOWN);
1416 else
1417 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1418
1419 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1420 if (err)
1421 goto err_remove_hwmon;
1422
1423 err = input_register_device(input_dev);
1424 if (err)
1425 goto err_remove_attr_group;
1426
1427 device_init_wakeup(&spi->dev, pdata->wakeup);
1428
1429 /*
1430 * If device does not carry platform data we must have allocated it
1431 * when parsing DT data.
1432 */
1433 if (!dev_get_platdata(&spi->dev))
1434 devm_kfree(&spi->dev, (void *)pdata);
1435
1436 return 0;
1437
1438 err_remove_attr_group:
1439 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1440 err_remove_hwmon:
1441 ads784x_hwmon_unregister(spi, ts);
1442 err_free_irq:
1443 free_irq(spi->irq, ts);
1444 err_disable_regulator:
1445 regulator_disable(ts->reg);
1446 err_put_regulator:
1447 regulator_put(ts->reg);
1448 err_free_gpio:
1449 if (!ts->get_pendown_state)
1450 gpio_free(ts->gpio_pendown);
1451 err_cleanup_filter:
1452 if (ts->filter_cleanup)
1453 ts->filter_cleanup(ts->filter_data);
1454 err_free_mem:
1455 input_free_device(input_dev);
1456 kfree(packet);
1457 kfree(ts);
1458 return err;
1459}
1460
1461static int ads7846_remove(struct spi_device *spi)
1462{
1463 struct ads7846 *ts = spi_get_drvdata(spi);
1464
1465 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1466
1467 ads7846_disable(ts);
1468 free_irq(ts->spi->irq, ts);
1469
1470 input_unregister_device(ts->input);
1471
1472 ads784x_hwmon_unregister(spi, ts);
1473
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 .pm = &ads7846_pm,
1499 .of_match_table = of_match_ptr(ads7846_dt_ids),
1500 },
1501 .probe = ads7846_probe,
1502 .remove = ads7846_remove,
1503};
1504
1505module_spi_driver(ads7846_driver);
1506
1507MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1508MODULE_LICENSE("GPL");
1509MODULE_ALIAS("spi:ads7846");
1510