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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 <[email protected]>
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/property.h>
28#include <linux/gpio/consumer.h>
29#include <linux/spi/spi.h>
30#include <linux/spi/ads7846.h>
31#include <linux/regulator/consumer.h>
32#include <linux/module.h>
33#include <linux/unaligned.h>
34
35/*
36 * This code has been heavily tested on a Nokia 770, and lightly
37 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
38 * TSC2046 is just newer ads7846 silicon.
39 * Support for ads7843 tested on Atmel at91sam926x-EK.
40 * Support for ads7845 has only been stubbed in.
41 * Support for Analog Devices AD7873 and AD7843 tested.
42 *
43 * IRQ handling needs a workaround because of a shortcoming in handling
44 * edge triggered IRQs on some platforms like the OMAP1/2. These
45 * platforms don't handle the ARM lazy IRQ disabling properly, thus we
46 * have to maintain our own SW IRQ disabled status. This should be
47 * removed as soon as the affected platform's IRQ handling is fixed.
48 *
49 * App note sbaa036 talks in more detail about accurate sampling...
50 * that ought to help in situations like LCDs inducing noise (which
51 * can also be helped by using synch signals) and more generally.
52 * This driver tries to utilize the measures described in the app
53 * note. The strength of filtering can be set in the board-* specific
54 * files.
55 */
56
57#define TS_POLL_DELAY 1 /* ms delay before the first sample */
58#define TS_POLL_PERIOD 5 /* ms delay between samples */
59
60/* this driver doesn't aim at the peak continuous sample rate */
61#define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
62
63struct ads7846_buf {
64 u8 cmd;
65 __be16 data;
66} __packed;
67
68struct ads7846_buf_layout {
69 unsigned int offset;
70 unsigned int count;
71 unsigned int skip;
72};
73
74/*
75 * We allocate this separately to avoid cache line sharing issues when
76 * driver is used with DMA-based SPI controllers (like atmel_spi) on
77 * systems where main memory is not DMA-coherent (most non-x86 boards).
78 */
79struct ads7846_packet {
80 unsigned int count;
81 unsigned int count_skip;
82 unsigned int cmds;
83 unsigned int last_cmd_idx;
84 struct ads7846_buf_layout l[5];
85 struct ads7846_buf *rx;
86 struct ads7846_buf *tx;
87
88 struct ads7846_buf pwrdown_cmd;
89
90 bool ignore;
91 u16 x, y, z1, z2;
92};
93
94struct ads7846 {
95 struct input_dev *input;
96 char phys[32];
97 char name[32];
98
99 struct spi_device *spi;
100 struct regulator *reg;
101
102 u16 model;
103 u16 vref_mv;
104 u16 vref_delay_usecs;
105 u16 x_plate_ohms;
106 u16 pressure_max;
107
108 bool swap_xy;
109 bool use_internal;
110
111 struct ads7846_packet *packet;
112
113 struct spi_transfer xfer[18];
114 struct spi_message msg[5];
115 int msg_count;
116 wait_queue_head_t wait;
117
118 bool pendown;
119
120 int read_cnt;
121 int read_rep;
122 int last_read;
123
124 u16 debounce_max;
125 u16 debounce_tol;
126 u16 debounce_rep;
127
128 u16 penirq_recheck_delay_usecs;
129
130 struct touchscreen_properties core_prop;
131
132 struct mutex lock;
133 bool stopped; /* P: lock */
134 bool disabled; /* P: lock */
135 bool suspended; /* P: lock */
136
137 int (*setup_spi_msg)(struct ads7846 *ts,
138 const struct ads7846_platform_data *pdata);
139 void (*read_state)(struct ads7846 *ts);
140 int (*filter)(void *data, int data_idx, int *val);
141 void *filter_data;
142 int (*get_pendown_state)(void);
143 struct gpio_desc *gpio_pendown;
144 struct gpio_desc *gpio_hsync;
145
146 void (*wait_for_sync)(void);
147};
148
149enum ads7846_filter {
150 ADS7846_FILTER_OK,
151 ADS7846_FILTER_REPEAT,
152 ADS7846_FILTER_IGNORE,
153};
154
155/* leave chip selected when we're done, for quicker re-select? */
156#if 0
157#define CS_CHANGE(xfer) ((xfer).cs_change = 1)
158#else
159#define CS_CHANGE(xfer) ((xfer).cs_change = 0)
160#endif
161
162/*--------------------------------------------------------------------------*/
163
164/* The ADS7846 has touchscreen and other sensors.
165 * Earlier ads784x chips are somewhat compatible.
166 */
167#define ADS_START (1 << 7)
168#define ADS_A2A1A0_d_y (1 << 4) /* differential */
169#define ADS_A2A1A0_d_z1 (3 << 4) /* differential */
170#define ADS_A2A1A0_d_z2 (4 << 4) /* differential */
171#define ADS_A2A1A0_d_x (5 << 4) /* differential */
172#define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */
173#define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */
174#define ADS_A2A1A0_vaux (6 << 4) /* non-differential */
175#define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */
176#define ADS_8_BIT (1 << 3)
177#define ADS_12_BIT (0 << 3)
178#define ADS_SER (1 << 2) /* non-differential */
179#define ADS_DFR (0 << 2) /* differential */
180#define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */
181#define ADS_PD10_ADC_ON (1 << 0) /* ADC on */
182#define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */
183#define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */
184
185#define MAX_12BIT ((1<<12)-1)
186
187/* leave ADC powered up (disables penirq) between differential samples */
188#define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
189 | ADS_12_BIT | ADS_DFR | \
190 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
191
192#define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref))
193#define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref))
194#define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref))
195#define READ_X(vref) (READ_12BIT_DFR(x, 1, vref))
196#define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */
197
198/* single-ended samples need to first power up reference voltage;
199 * we leave both ADC and VREF powered
200 */
201#define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
202 | ADS_12_BIT | ADS_SER)
203
204#define REF_ON (READ_12BIT_DFR(x, 1, 1))
205#define REF_OFF (READ_12BIT_DFR(y, 0, 0))
206
207/* Order commands in the most optimal way to reduce Vref switching and
208 * settling time:
209 * Measure: X; Vref: X+, X-; IN: Y+
210 * Measure: Y; Vref: Y+, Y-; IN: X+
211 * Measure: Z1; Vref: Y+, X-; IN: X+
212 * Measure: Z2; Vref: Y+, X-; IN: Y-
213 */
214enum ads7846_cmds {
215 ADS7846_X,
216 ADS7846_Y,
217 ADS7846_Z1,
218 ADS7846_Z2,
219 ADS7846_PWDOWN,
220};
221
222static int get_pendown_state(struct ads7846 *ts)
223{
224 if (ts->get_pendown_state)
225 return ts->get_pendown_state();
226
227 return gpiod_get_value(ts->gpio_pendown);
228}
229
230static void ads7846_report_pen_up(struct ads7846 *ts)
231{
232 struct input_dev *input = ts->input;
233
234 input_report_key(input, BTN_TOUCH, 0);
235 input_report_abs(input, ABS_PRESSURE, 0);
236 input_sync(input);
237
238 ts->pendown = false;
239 dev_vdbg(&ts->spi->dev, "UP\n");
240}
241
242/* Must be called with ts->lock held */
243static void ads7846_stop(struct ads7846 *ts)
244{
245 if (!ts->disabled && !ts->suspended) {
246 /* Signal IRQ thread to stop polling and disable the handler. */
247 ts->stopped = true;
248 mb();
249 wake_up(&ts->wait);
250 disable_irq(ts->spi->irq);
251 }
252}
253
254/* Must be called with ts->lock held */
255static void ads7846_restart(struct ads7846 *ts)
256{
257 if (!ts->disabled && !ts->suspended) {
258 /* Check if pen was released since last stop */
259 if (ts->pendown && !get_pendown_state(ts))
260 ads7846_report_pen_up(ts);
261
262 /* Tell IRQ thread that it may poll the device. */
263 ts->stopped = false;
264 mb();
265 enable_irq(ts->spi->irq);
266 }
267}
268
269/* Must be called with ts->lock held */
270static void __ads7846_disable(struct ads7846 *ts)
271{
272 ads7846_stop(ts);
273 regulator_disable(ts->reg);
274
275 /*
276 * We know the chip's in low power mode since we always
277 * leave it that way after every request
278 */
279}
280
281/* Must be called with ts->lock held */
282static void __ads7846_enable(struct ads7846 *ts)
283{
284 int error;
285
286 error = regulator_enable(ts->reg);
287 if (error != 0)
288 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error);
289
290 ads7846_restart(ts);
291}
292
293static void ads7846_disable(struct ads7846 *ts)
294{
295 guard(mutex)(&ts->lock);
296
297 if (!ts->disabled) {
298
299 if (!ts->suspended)
300 __ads7846_disable(ts);
301
302 ts->disabled = true;
303 }
304}
305
306static void ads7846_enable(struct ads7846 *ts)
307{
308 guard(mutex)(&ts->lock);
309
310 if (ts->disabled) {
311
312 ts->disabled = false;
313
314 if (!ts->suspended)
315 __ads7846_enable(ts);
316 }
317}
318
319/*--------------------------------------------------------------------------*/
320
321/*
322 * Non-touchscreen sensors only use single-ended conversions.
323 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
324 * ads7846 lets that pin be unconnected, to use internal vREF.
325 */
326
327struct ser_req {
328 u8 ref_on;
329 u8 command;
330 u8 ref_off;
331 struct spi_message msg;
332 struct spi_transfer xfer[8];
333 /*
334 * DMA (thus cache coherency maintenance) requires the
335 * transfer buffers to live in their own cache lines.
336 */
337 __be16 sample ____cacheline_aligned;
338 u16 scratch;
339};
340
341struct ads7845_ser_req {
342 u8 command[3];
343 struct spi_message msg;
344 struct spi_transfer xfer[2];
345 /*
346 * DMA (thus cache coherency maintenance) requires the
347 * transfer buffers to live in their own cache lines.
348 */
349 u8 sample[3] ____cacheline_aligned;
350};
351
352static int ads7846_read12_ser(struct device *dev, unsigned command)
353{
354 struct spi_device *spi = to_spi_device(dev);
355 struct ads7846 *ts = dev_get_drvdata(dev);
356 int status;
357
358 struct ser_req *req __free(kfree) = kzalloc_obj(*req);
359 if (!req)
360 return -ENOMEM;
361
362 spi_message_init(&req->msg);
363
364 /* maybe turn on internal vREF, and let it settle */
365 if (ts->use_internal) {
366 req->ref_on = REF_ON;
367 req->xfer[0].tx_buf = &req->ref_on;
368 req->xfer[0].len = 1;
369 spi_message_add_tail(&req->xfer[0], &req->msg);
370
371 req->xfer[1].rx_buf = &req->scratch;
372 req->xfer[1].len = 2;
373
374 /* for 1uF, settle for 800 usec; no cap, 100 usec. */
375 req->xfer[1].delay.value = ts->vref_delay_usecs;
376 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS;
377 spi_message_add_tail(&req->xfer[1], &req->msg);
378
379 /* Enable reference voltage */
380 command |= ADS_PD10_REF_ON;
381 }
382
383 /* Enable ADC in every case */
384 command |= ADS_PD10_ADC_ON;
385
386 /* take sample */
387 req->command = (u8) command;
388 req->xfer[2].tx_buf = &req->command;
389 req->xfer[2].len = 1;
390 spi_message_add_tail(&req->xfer[2], &req->msg);
391
392 req->xfer[3].rx_buf = &req->sample;
393 req->xfer[3].len = 2;
394 spi_message_add_tail(&req->xfer[3], &req->msg);
395
396 /* REVISIT: take a few more samples, and compare ... */
397
398 /* converter in low power mode & enable PENIRQ */
399 req->ref_off = PWRDOWN;
400 req->xfer[4].tx_buf = &req->ref_off;
401 req->xfer[4].len = 1;
402 spi_message_add_tail(&req->xfer[4], &req->msg);
403
404 req->xfer[5].rx_buf = &req->scratch;
405 req->xfer[5].len = 2;
406 spi_message_add_tail(&req->xfer[5], &req->msg);
407
408 /* clear the command register */
409 req->xfer[6].rx_buf = &req->scratch;
410 req->xfer[6].len = 1;
411 spi_message_add_tail(&req->xfer[6], &req->msg);
412
413 req->xfer[7].rx_buf = &req->scratch;
414 req->xfer[7].len = 2;
415 CS_CHANGE(req->xfer[7]);
416 spi_message_add_tail(&req->xfer[7], &req->msg);
417
418 scoped_guard(mutex, &ts->lock) {
419 ads7846_stop(ts);
420 status = spi_sync(spi, &req->msg);
421 ads7846_restart(ts);
422 }
423
424 if (status == 0) {
425 /* on-wire is a must-ignore bit, a BE12 value, then padding */
426 status = be16_to_cpu(req->sample);
427 status = status >> 3;
428 status &= 0x0fff;
429 }
430
431 return status;
432}
433
434static int ads7845_read12_ser(struct device *dev, unsigned command)
435{
436 struct spi_device *spi = to_spi_device(dev);
437 struct ads7846 *ts = dev_get_drvdata(dev);
438 int status;
439
440 struct ads7845_ser_req *req __free(kfree) = kzalloc_obj(*req);
441 if (!req)
442 return -ENOMEM;
443
444 spi_message_init(&req->msg);
445
446 req->command[0] = (u8) command;
447 req->xfer[0].tx_buf = req->command;
448 req->xfer[0].rx_buf = req->sample;
449 req->xfer[0].len = 3;
450 spi_message_add_tail(&req->xfer[0], &req->msg);
451
452 scoped_guard(mutex, &ts->lock) {
453 ads7846_stop(ts);
454 status = spi_sync(spi, &req->msg);
455 ads7846_restart(ts);
456 }
457
458 if (status == 0) {
459 /* BE12 value, then padding */
460 status = get_unaligned_be16(&req->sample[1]);
461 status = status >> 3;
462 status &= 0x0fff;
463 }
464
465 return status;
466}
467
468#if IS_ENABLED(CONFIG_HWMON)
469
470#define SHOW(name, var, adjust) static ssize_t \
471name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
472{ \
473 struct ads7846 *ts = dev_get_drvdata(dev); \
474 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \
475 READ_12BIT_SER(var)); \
476 if (v < 0) \
477 return v; \
478 return sprintf(buf, "%u\n", adjust(ts, v)); \
479} \
480static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
481
482
483/* Sysfs conventions report temperatures in millidegrees Celsius.
484 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
485 * accuracy scheme without calibration data. For now we won't try either;
486 * userspace sees raw sensor values, and must scale/calibrate appropriately.
487 */
488static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
489{
490 return v;
491}
492
493SHOW(temp0, temp0, null_adjust) /* temp1_input */
494SHOW(temp1, temp1, null_adjust) /* temp2_input */
495
496
497/* sysfs conventions report voltages in millivolts. We can convert voltages
498 * if we know vREF. userspace may need to scale vAUX to match the board's
499 * external resistors; we assume that vBATT only uses the internal ones.
500 */
501static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
502{
503 unsigned retval = v;
504
505 /* external resistors may scale vAUX into 0..vREF */
506 retval *= ts->vref_mv;
507 retval = retval >> 12;
508
509 return retval;
510}
511
512static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
513{
514 unsigned retval = vaux_adjust(ts, v);
515
516 /* ads7846 has a resistor ladder to scale this signal down */
517 if (ts->model == 7846)
518 retval *= 4;
519
520 return retval;
521}
522
523SHOW(in0_input, vaux, vaux_adjust)
524SHOW(in1_input, vbatt, vbatt_adjust)
525
526static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr,
527 int index)
528{
529 struct device *dev = kobj_to_dev(kobj);
530 struct ads7846 *ts = dev_get_drvdata(dev);
531
532 if (ts->model == 7843 && index < 2) /* in0, in1 */
533 return 0;
534 if (ts->model == 7845 && index != 2) /* in0 */
535 return 0;
536
537 return attr->mode;
538}
539
540static struct attribute *ads7846_attributes[] = {
541 &dev_attr_temp0.attr, /* 0 */
542 &dev_attr_temp1.attr, /* 1 */
543 &dev_attr_in0_input.attr, /* 2 */
544 &dev_attr_in1_input.attr, /* 3 */
545 NULL,
546};
547
548static const struct attribute_group ads7846_attr_group = {
549 .attrs = ads7846_attributes,
550 .is_visible = ads7846_is_visible,
551};
552__ATTRIBUTE_GROUPS(ads7846_attr);
553
554static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
555{
556 struct device *hwmon;
557
558 /* hwmon sensors need a reference voltage */
559 switch (ts->model) {
560 case 7846:
561 if (!ts->vref_mv) {
562 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
563 ts->vref_mv = 2500;
564 ts->use_internal = true;
565 }
566 break;
567 case 7845:
568 case 7843:
569 if (!ts->vref_mv) {
570 dev_warn(&spi->dev,
571 "external vREF for ADS%d not specified\n",
572 ts->model);
573 return 0;
574 }
575 break;
576 }
577
578 hwmon = devm_hwmon_device_register_with_groups(&spi->dev,
579 spi->modalias, ts,
580 ads7846_attr_groups);
581
582 return PTR_ERR_OR_ZERO(hwmon);
583}
584
585#else
586static inline int ads784x_hwmon_register(struct spi_device *spi,
587 struct ads7846 *ts)
588{
589 return 0;
590}
591#endif
592
593static ssize_t ads7846_pen_down_show(struct device *dev,
594 struct device_attribute *attr, char *buf)
595{
596 struct ads7846 *ts = dev_get_drvdata(dev);
597
598 return sprintf(buf, "%u\n", ts->pendown);
599}
600
601static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
602
603static ssize_t ads7846_disable_show(struct device *dev,
604 struct device_attribute *attr, char *buf)
605{
606 struct ads7846 *ts = dev_get_drvdata(dev);
607
608 return sprintf(buf, "%u\n", ts->disabled);
609}
610
611static ssize_t ads7846_disable_store(struct device *dev,
612 struct device_attribute *attr,
613 const char *buf, size_t count)
614{
615 struct ads7846 *ts = dev_get_drvdata(dev);
616 unsigned int i;
617 int err;
618
619 err = kstrtouint(buf, 10, &i);
620 if (err)
621 return err;
622
623 if (i)
624 ads7846_disable(ts);
625 else
626 ads7846_enable(ts);
627
628 return count;
629}
630
631static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
632
633static struct attribute *ads784x_attrs[] = {
634 &dev_attr_pen_down.attr,
635 &dev_attr_disable.attr,
636 NULL,
637};
638ATTRIBUTE_GROUPS(ads784x);
639
640/*--------------------------------------------------------------------------*/
641
642static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
643{
644 struct ads7846 *ts = ads;
645
646 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
647 /* Start over collecting consistent readings. */
648 ts->read_rep = 0;
649 /*
650 * Repeat it, if this was the first read or the read
651 * wasn't consistent enough.
652 */
653 if (ts->read_cnt < ts->debounce_max) {
654 ts->last_read = *val;
655 ts->read_cnt++;
656 return ADS7846_FILTER_REPEAT;
657 } else {
658 /*
659 * Maximum number of debouncing reached and still
660 * not enough number of consistent readings. Abort
661 * the whole sample, repeat it in the next sampling
662 * period.
663 */
664 ts->read_cnt = 0;
665 return ADS7846_FILTER_IGNORE;
666 }
667 } else {
668 if (++ts->read_rep > ts->debounce_rep) {
669 /*
670 * Got a good reading for this coordinate,
671 * go for the next one.
672 */
673 ts->read_cnt = 0;
674 ts->read_rep = 0;
675 return ADS7846_FILTER_OK;
676 } else {
677 /* Read more values that are consistent. */
678 ts->read_cnt++;
679 return ADS7846_FILTER_REPEAT;
680 }
681 }
682}
683
684static int ads7846_no_filter(void *ads, int data_idx, int *val)
685{
686 return ADS7846_FILTER_OK;
687}
688
689static int ads7846_get_value(struct ads7846_buf *buf)
690{
691 int value;
692
693 value = be16_to_cpup(&buf->data);
694
695 /* enforce ADC output is 12 bits width */
696 return (value >> 3) & 0xfff;
697}
698
699static void ads7846_set_cmd_val(struct ads7846 *ts, enum ads7846_cmds cmd_idx,
700 u16 val)
701{
702 struct ads7846_packet *packet = ts->packet;
703
704 switch (cmd_idx) {
705 case ADS7846_Y:
706 packet->y = val;
707 break;
708 case ADS7846_X:
709 packet->x = val;
710 break;
711 case ADS7846_Z1:
712 packet->z1 = val;
713 break;
714 case ADS7846_Z2:
715 packet->z2 = val;
716 break;
717 default:
718 WARN_ON_ONCE(1);
719 }
720}
721
722static u8 ads7846_get_cmd(enum ads7846_cmds cmd_idx, int vref)
723{
724 switch (cmd_idx) {
725 case ADS7846_Y:
726 return READ_Y(vref);
727 case ADS7846_X:
728 return READ_X(vref);
729
730 /* 7846 specific commands */
731 case ADS7846_Z1:
732 return READ_Z1(vref);
733 case ADS7846_Z2:
734 return READ_Z2(vref);
735 case ADS7846_PWDOWN:
736 return PWRDOWN;
737 default:
738 WARN_ON_ONCE(1);
739 }
740
741 return 0;
742}
743
744static bool ads7846_cmd_need_settle(enum ads7846_cmds cmd_idx)
745{
746 switch (cmd_idx) {
747 case ADS7846_X:
748 case ADS7846_Y:
749 case ADS7846_Z1:
750 case ADS7846_Z2:
751 return true;
752 case ADS7846_PWDOWN:
753 return false;
754 default:
755 WARN_ON_ONCE(1);
756 }
757
758 return false;
759}
760
761static int ads7846_filter(struct ads7846 *ts)
762{
763 struct ads7846_packet *packet = ts->packet;
764 int action;
765 int val;
766 unsigned int cmd_idx, b;
767
768 packet->ignore = false;
769 for (cmd_idx = packet->last_cmd_idx; cmd_idx < packet->cmds - 1; cmd_idx++) {
770 struct ads7846_buf_layout *l = &packet->l[cmd_idx];
771
772 packet->last_cmd_idx = cmd_idx;
773
774 for (b = l->skip; b < l->count; b++) {
775 val = ads7846_get_value(&packet->rx[l->offset + b]);
776
777 action = ts->filter(ts->filter_data, cmd_idx, &val);
778 if (action == ADS7846_FILTER_REPEAT) {
779 if (b == l->count - 1)
780 return -EAGAIN;
781 } else if (action == ADS7846_FILTER_OK) {
782 ads7846_set_cmd_val(ts, cmd_idx, val);
783 break;
784 } else {
785 packet->ignore = true;
786 return 0;
787 }
788 }
789 }
790
791 return 0;
792}
793
794static int ads7846_filter_one(struct ads7846 *ts, unsigned int cmd_idx)
795{
796 struct ads7846_packet *packet = ts->packet;
797 struct ads7846_buf_layout *l = &packet->l[cmd_idx];
798 int action, val;
799
800 val = ads7846_get_value(&packet->rx[l->offset + l->count - 1]);
801 action = ts->filter(ts->filter_data, cmd_idx, &val);
802 if (action == ADS7846_FILTER_REPEAT)
803 return -EAGAIN;
804 else if (action != ADS7846_FILTER_OK)
805 return -EIO;
806 ads7846_set_cmd_val(ts, cmd_idx, val);
807 return 0;
808}
809
810static void ads7846_wait_for_hsync(struct ads7846 *ts)
811{
812 if (ts->wait_for_sync) {
813 ts->wait_for_sync();
814 return;
815 }
816
817 if (!ts->gpio_hsync)
818 return;
819
820 /*
821 * Wait for HSYNC to assert the line should be flagged
822 * as active low so here we are waiting for it to assert
823 */
824 while (!gpiod_get_value(ts->gpio_hsync))
825 cpu_relax();
826
827 /* Then we wait for it do de-assert */
828 while (gpiod_get_value(ts->gpio_hsync))
829 cpu_relax();
830}
831
832static void ads7846_halfd_read_state(struct ads7846 *ts)
833{
834 struct ads7846_packet *packet = ts->packet;
835 int msg_idx = 0;
836
837 packet->ignore = false;
838
839 while (msg_idx < ts->msg_count) {
840 int error;
841
842 ads7846_wait_for_hsync(ts);
843
844 error = spi_sync(ts->spi, &ts->msg[msg_idx]);
845 if (error) {
846 dev_err_ratelimited(&ts->spi->dev, "spi_sync --> %d\n",
847 error);
848 packet->ignore = true;
849 return;
850 }
851
852 /*
853 * Last message is power down request, no need to convert
854 * or filter the value.
855 */
856 if (msg_idx == ts->msg_count - 1)
857 break;
858
859 error = ads7846_filter_one(ts, msg_idx);
860 if (error == -EAGAIN) {
861 continue;
862 } else if (error) {
863 packet->ignore = true;
864 msg_idx = ts->msg_count - 1;
865 } else {
866 msg_idx++;
867 }
868 }
869}
870
871static void ads7846_read_state(struct ads7846 *ts)
872{
873 struct ads7846_packet *packet = ts->packet;
874 struct spi_message *m;
875 int msg_idx = 0;
876 int error;
877
878 packet->last_cmd_idx = 0;
879
880 while (true) {
881 ads7846_wait_for_hsync(ts);
882
883 m = &ts->msg[msg_idx];
884 error = spi_sync(ts->spi, m);
885 if (error) {
886 dev_err_ratelimited(&ts->spi->dev, "spi_sync --> %d\n", error);
887 packet->ignore = true;
888 return;
889 }
890
891 error = ads7846_filter(ts);
892 if (error)
893 continue;
894
895 return;
896 }
897}
898
899static void ads7846_report_state(struct ads7846 *ts)
900{
901 struct ads7846_packet *packet = ts->packet;
902 unsigned int Rt;
903 u16 x, y, z1, z2;
904
905 x = packet->x;
906 y = packet->y;
907 if (ts->model == 7845) {
908 z1 = 0;
909 z2 = 0;
910 } else {
911 z1 = packet->z1;
912 z2 = packet->z2;
913 }
914
915 /* range filtering */
916 if (x == MAX_12BIT)
917 x = 0;
918
919 if (ts->model == 7843 || ts->model == 7845) {
920 Rt = ts->pressure_max / 2;
921 } else if (likely(x && z1)) {
922 /* compute touch pressure resistance using equation #2 */
923 Rt = z2;
924 Rt -= z1;
925 Rt *= ts->x_plate_ohms;
926 Rt = DIV_ROUND_CLOSEST(Rt, 16);
927 Rt *= x;
928 Rt /= z1;
929 Rt = DIV_ROUND_CLOSEST(Rt, 256);
930 } else {
931 Rt = 0;
932 }
933
934 /*
935 * Sample found inconsistent by debouncing or pressure is beyond
936 * the maximum. Don't report it to user space, repeat at least
937 * once more the measurement
938 */
939 if (packet->ignore || Rt > ts->pressure_max) {
940 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
941 packet->ignore, Rt);
942 return;
943 }
944
945 /*
946 * Maybe check the pendown state before reporting. This discards
947 * false readings when the pen is lifted.
948 */
949 if (ts->penirq_recheck_delay_usecs) {
950 udelay(ts->penirq_recheck_delay_usecs);
951 if (!get_pendown_state(ts))
952 Rt = 0;
953 }
954
955 /*
956 * NOTE: We can't rely on the pressure to determine the pen down
957 * state, even this controller has a pressure sensor. The pressure
958 * value can fluctuate for quite a while after lifting the pen and
959 * in some cases may not even settle at the expected value.
960 *
961 * The only safe way to check for the pen up condition is in the
962 * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
963 */
964 if (Rt) {
965 struct input_dev *input = ts->input;
966
967 if (!ts->pendown) {
968 input_report_key(input, BTN_TOUCH, 1);
969 ts->pendown = true;
970 dev_vdbg(&ts->spi->dev, "DOWN\n");
971 }
972
973 touchscreen_report_pos(input, &ts->core_prop, x, y, false);
974 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
975
976 input_sync(input);
977 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
978 }
979}
980
981static irqreturn_t ads7846_hard_irq(int irq, void *handle)
982{
983 struct ads7846 *ts = handle;
984
985 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
986}
987
988
989static irqreturn_t ads7846_irq(int irq, void *handle)
990{
991 struct ads7846 *ts = handle;
992
993 /* Start with a small delay before checking pendown state */
994 msleep(TS_POLL_DELAY);
995
996 while (!ts->stopped && get_pendown_state(ts)) {
997
998 /* pen is down, continue with the measurement */
999 ts->read_state(ts);
1000
1001 if (!ts->stopped)
1002 ads7846_report_state(ts);
1003
1004 wait_event_timeout(ts->wait, ts->stopped,
1005 msecs_to_jiffies(TS_POLL_PERIOD));
1006 }
1007
1008 if (ts->pendown && !ts->stopped)
1009 ads7846_report_pen_up(ts);
1010
1011 return IRQ_HANDLED;
1012}
1013
1014static int ads7846_suspend(struct device *dev)
1015{
1016 struct ads7846 *ts = dev_get_drvdata(dev);
1017
1018 guard(mutex)(&ts->lock);
1019
1020 if (!ts->suspended) {
1021
1022 if (!ts->disabled)
1023 __ads7846_disable(ts);
1024
1025 if (device_may_wakeup(&ts->spi->dev))
1026 enable_irq_wake(ts->spi->irq);
1027
1028 ts->suspended = true;
1029 }
1030
1031 return 0;
1032}
1033
1034static int ads7846_resume(struct device *dev)
1035{
1036 struct ads7846 *ts = dev_get_drvdata(dev);
1037
1038 guard(mutex)(&ts->lock);
1039
1040 if (ts->suspended) {
1041
1042 ts->suspended = false;
1043
1044 if (device_may_wakeup(&ts->spi->dev))
1045 disable_irq_wake(ts->spi->irq);
1046
1047 if (!ts->disabled)
1048 __ads7846_enable(ts);
1049 }
1050
1051 return 0;
1052}
1053
1054static DEFINE_SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
1055
1056static int ads7846_setup_pendown(struct spi_device *spi,
1057 struct ads7846 *ts,
1058 const struct ads7846_platform_data *pdata)
1059{
1060 /*
1061 * REVISIT when the irq can be triggered active-low, or if for some
1062 * reason the touchscreen isn't hooked up, we don't need to access
1063 * the pendown state.
1064 */
1065
1066 if (pdata->get_pendown_state) {
1067 ts->get_pendown_state = pdata->get_pendown_state;
1068 } else {
1069 ts->gpio_pendown = devm_gpiod_get(&spi->dev, "pendown", GPIOD_IN);
1070 if (IS_ERR(ts->gpio_pendown)) {
1071 dev_err(&spi->dev, "failed to request pendown GPIO\n");
1072 return PTR_ERR(ts->gpio_pendown);
1073 }
1074 if (pdata->gpio_pendown_debounce)
1075 gpiod_set_debounce(ts->gpio_pendown,
1076 pdata->gpio_pendown_debounce);
1077 }
1078
1079 return 0;
1080}
1081
1082/*
1083 * Set up the transfers to read touchscreen state; this assumes we
1084 * use formula #2 for pressure, not #3.
1085 */
1086static int ads7846_halfd_spi_msg(struct ads7846 *ts,
1087 const struct ads7846_platform_data *pdata)
1088{
1089 struct spi_message *m = ts->msg;
1090 struct spi_transfer *x = ts->xfer;
1091 struct ads7846_packet *packet = ts->packet;
1092 int vref = pdata->keep_vref_on;
1093 unsigned int offset = 0;
1094 unsigned int cmd_idx, b;
1095 size_t size = 0;
1096
1097 if (pdata->settle_delay_usecs)
1098 packet->count = 2;
1099 else
1100 packet->count = 1;
1101
1102 if (ts->model == 7846)
1103 packet->cmds = 5; /* x, y, z1, z2, pwdown */
1104 else
1105 packet->cmds = 3; /* x, y, pwdown */
1106
1107 for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) {
1108 struct ads7846_buf_layout *l = &packet->l[cmd_idx];
1109 unsigned int max_count;
1110
1111 if (cmd_idx == packet->cmds - 1) {
1112 cmd_idx = ADS7846_PWDOWN;
1113 max_count = 1;
1114 } else {
1115 max_count = packet->count;
1116 }
1117
1118 l->offset = offset;
1119 offset += max_count;
1120 l->count = max_count;
1121 l->skip = 0;
1122 size += sizeof(*packet->rx) * max_count;
1123 }
1124
1125 /* We use two transfers per command. */
1126 if (ARRAY_SIZE(ts->xfer) < offset * 2)
1127 return -ENOMEM;
1128
1129 packet->rx = devm_kzalloc(&ts->spi->dev, size, GFP_KERNEL);
1130 if (!packet->rx)
1131 return -ENOMEM;
1132
1133 if (ts->model == 7873) {
1134 /*
1135 * The AD7873 is almost identical to the ADS7846
1136 * keep VREF off during differential/ratiometric
1137 * conversion modes.
1138 */
1139 ts->model = 7846;
1140 vref = 0;
1141 }
1142
1143 ts->msg_count = 0;
1144
1145 for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) {
1146 struct ads7846_buf_layout *l = &packet->l[cmd_idx];
1147 u8 cmd;
1148
1149 ts->msg_count++;
1150 spi_message_init(m);
1151 m->context = ts;
1152
1153 if (cmd_idx == packet->cmds - 1)
1154 cmd_idx = ADS7846_PWDOWN;
1155
1156 cmd = ads7846_get_cmd(cmd_idx, vref);
1157
1158 for (b = 0; b < l->count; b++) {
1159 packet->rx[l->offset + b].cmd = cmd;
1160 x->tx_buf = &packet->rx[l->offset + b].cmd;
1161 x->len = 1;
1162 spi_message_add_tail(x, m);
1163 x++;
1164 x->rx_buf = &packet->rx[l->offset + b].data;
1165 x->len = 2;
1166 if (b < l->count - 1 && l->count > 1) {
1167 x->delay.value = pdata->settle_delay_usecs;
1168 x->delay.unit = SPI_DELAY_UNIT_USECS;
1169 }
1170 spi_message_add_tail(x, m);
1171 x++;
1172 }
1173 m++;
1174 }
1175 return 0;
1176}
1177
1178/*
1179 * Set up the transfers to read touchscreen state; this assumes we
1180 * use formula #2 for pressure, not #3.
1181 */
1182static int ads7846_setup_spi_msg(struct ads7846 *ts,
1183 const struct ads7846_platform_data *pdata)
1184{
1185 struct spi_message *m = &ts->msg[0];
1186 struct spi_transfer *x = ts->xfer;
1187 struct ads7846_packet *packet = ts->packet;
1188 int vref = pdata->keep_vref_on;
1189 unsigned int count, offset = 0;
1190 unsigned int cmd_idx, b;
1191 unsigned long time;
1192 size_t size = 0;
1193
1194 /* time per bit */
1195 time = NSEC_PER_SEC / ts->spi->max_speed_hz;
1196
1197 count = pdata->settle_delay_usecs * NSEC_PER_USEC / time;
1198 packet->count_skip = DIV_ROUND_UP(count, 24);
1199
1200 if (ts->debounce_max && ts->debounce_rep)
1201 /* ads7846_debounce_filter() is making ts->debounce_rep + 2
1202 * reads. So we need to get all samples for normal case. */
1203 packet->count = ts->debounce_rep + 2;
1204 else
1205 packet->count = 1;
1206
1207 if (ts->model == 7846)
1208 packet->cmds = 5; /* x, y, z1, z2, pwdown */
1209 else
1210 packet->cmds = 3; /* x, y, pwdown */
1211
1212 for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) {
1213 struct ads7846_buf_layout *l = &packet->l[cmd_idx];
1214 unsigned int max_count;
1215
1216 if (cmd_idx == packet->cmds - 1)
1217 cmd_idx = ADS7846_PWDOWN;
1218
1219 if (ads7846_cmd_need_settle(cmd_idx))
1220 max_count = packet->count + packet->count_skip;
1221 else
1222 max_count = packet->count;
1223
1224 l->offset = offset;
1225 offset += max_count;
1226 l->count = max_count;
1227 l->skip = packet->count_skip;
1228 size += sizeof(*packet->tx) * max_count;
1229 }
1230
1231 packet->tx = devm_kzalloc(&ts->spi->dev, size, GFP_KERNEL);
1232 if (!packet->tx)
1233 return -ENOMEM;
1234
1235 packet->rx = devm_kzalloc(&ts->spi->dev, size, GFP_KERNEL);
1236 if (!packet->rx)
1237 return -ENOMEM;
1238
1239 if (ts->model == 7873) {
1240 /*
1241 * The AD7873 is almost identical to the ADS7846
1242 * keep VREF off during differential/ratiometric
1243 * conversion modes.
1244 */
1245 ts->model = 7846;
1246 vref = 0;
1247 }
1248
1249 ts->msg_count = 1;
1250 spi_message_init(m);
1251 m->context = ts;
1252
1253 for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) {
1254 struct ads7846_buf_layout *l = &packet->l[cmd_idx];
1255 u8 cmd;
1256
1257 if (cmd_idx == packet->cmds - 1)
1258 cmd_idx = ADS7846_PWDOWN;
1259
1260 cmd = ads7846_get_cmd(cmd_idx, vref);
1261
1262 for (b = 0; b < l->count; b++)
1263 packet->tx[l->offset + b].cmd = cmd;
1264 }
1265
1266 x->tx_buf = packet->tx;
1267 x->rx_buf = packet->rx;
1268 x->len = size;
1269 spi_message_add_tail(x, m);
1270
1271 return 0;
1272}
1273
1274static const struct of_device_id ads7846_dt_ids[] = {
1275 { .compatible = "ti,tsc2046", .data = (void *) 7846 },
1276 { .compatible = "ti,ads7843", .data = (void *) 7843 },
1277 { .compatible = "ti,ads7845", .data = (void *) 7845 },
1278 { .compatible = "ti,ads7846", .data = (void *) 7846 },
1279 { .compatible = "ti,ads7873", .data = (void *) 7873 },
1280 { }
1281};
1282MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1283
1284static const struct spi_device_id ads7846_spi_ids[] = {
1285 { "tsc2046", 7846 },
1286 { "ads7843", 7843 },
1287 { "ads7845", 7845 },
1288 { "ads7846", 7846 },
1289 { "ads7873", 7873 },
1290 { },
1291};
1292MODULE_DEVICE_TABLE(spi, ads7846_spi_ids);
1293
1294static const struct ads7846_platform_data *ads7846_get_props(struct device *dev)
1295{
1296 struct ads7846_platform_data *pdata;
1297 u32 value;
1298
1299 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1300 if (!pdata)
1301 return ERR_PTR(-ENOMEM);
1302
1303 pdata->model = (uintptr_t)device_get_match_data(dev);
1304
1305 device_property_read_u16(dev, "ti,vref-delay-usecs",
1306 &pdata->vref_delay_usecs);
1307 device_property_read_u16(dev, "ti,vref-mv", &pdata->vref_mv);
1308 pdata->keep_vref_on = device_property_read_bool(dev, "ti,keep-vref-on");
1309
1310 pdata->swap_xy = device_property_read_bool(dev, "ti,swap-xy");
1311
1312 device_property_read_u16(dev, "ti,settle-delay-usec",
1313 &pdata->settle_delay_usecs);
1314 device_property_read_u16(dev, "ti,penirq-recheck-delay-usecs",
1315 &pdata->penirq_recheck_delay_usecs);
1316
1317 device_property_read_u16(dev, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1318 device_property_read_u16(dev, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1319
1320 device_property_read_u16(dev, "ti,x-min", &pdata->x_min);
1321 device_property_read_u16(dev, "ti,y-min", &pdata->y_min);
1322 device_property_read_u16(dev, "ti,x-max", &pdata->x_max);
1323 device_property_read_u16(dev, "ti,y-max", &pdata->y_max);
1324
1325 /*
1326 * touchscreen-max-pressure gets parsed during
1327 * touchscreen_parse_properties()
1328 */
1329 device_property_read_u16(dev, "ti,pressure-min", &pdata->pressure_min);
1330 if (!device_property_read_u32(dev, "touchscreen-min-pressure", &value))
1331 pdata->pressure_min = (u16) value;
1332 device_property_read_u16(dev, "ti,pressure-max", &pdata->pressure_max);
1333
1334 device_property_read_u16(dev, "ti,debounce-max", &pdata->debounce_max);
1335 if (!device_property_read_u32(dev, "touchscreen-average-samples", &value))
1336 pdata->debounce_max = (u16) value;
1337 device_property_read_u16(dev, "ti,debounce-tol", &pdata->debounce_tol);
1338 device_property_read_u16(dev, "ti,debounce-rep", &pdata->debounce_rep);
1339
1340 device_property_read_u32(dev, "ti,pendown-gpio-debounce",
1341 &pdata->gpio_pendown_debounce);
1342
1343 pdata->wakeup = device_property_read_bool(dev, "wakeup-source") ||
1344 device_property_read_bool(dev, "linux,wakeup");
1345
1346 return pdata;
1347}
1348
1349static void ads7846_regulator_disable(void *regulator)
1350{
1351 regulator_disable(regulator);
1352}
1353
1354static int ads7846_probe(struct spi_device *spi)
1355{
1356 const struct ads7846_platform_data *pdata;
1357 struct ads7846 *ts;
1358 struct device *dev = &spi->dev;
1359 struct ads7846_packet *packet;
1360 struct input_dev *input_dev;
1361 unsigned long irq_flags;
1362 int err;
1363
1364 if (!spi->irq) {
1365 dev_dbg(dev, "no IRQ?\n");
1366 return -EINVAL;
1367 }
1368
1369 /* don't exceed max specified sample rate */
1370 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1371 dev_err(dev, "f(sample) %d KHz?\n",
1372 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1373 return -EINVAL;
1374 }
1375
1376 /*
1377 * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1378 * that even if the hardware can do that, the SPI controller driver
1379 * may not. So we stick to very-portable 8 bit words, both RX and TX.
1380 */
1381 spi->bits_per_word = 8;
1382 spi->mode &= ~SPI_MODE_X_MASK;
1383 spi->mode |= SPI_MODE_0;
1384 err = spi_setup(spi);
1385 if (err < 0)
1386 return err;
1387
1388 ts = devm_kzalloc(dev, sizeof(struct ads7846), GFP_KERNEL);
1389 if (!ts)
1390 return -ENOMEM;
1391
1392 if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) {
1393 ts->setup_spi_msg = ads7846_halfd_spi_msg;
1394 ts->read_state = ads7846_halfd_read_state;
1395 } else {
1396 ts->setup_spi_msg = ads7846_setup_spi_msg;
1397 ts->read_state = ads7846_read_state;
1398 }
1399
1400 packet = devm_kzalloc(dev, sizeof(struct ads7846_packet), GFP_KERNEL);
1401 if (!packet)
1402 return -ENOMEM;
1403
1404 input_dev = devm_input_allocate_device(dev);
1405 if (!input_dev)
1406 return -ENOMEM;
1407
1408 spi_set_drvdata(spi, ts);
1409
1410 ts->packet = packet;
1411 ts->spi = spi;
1412 ts->input = input_dev;
1413
1414 mutex_init(&ts->lock);
1415 init_waitqueue_head(&ts->wait);
1416
1417 pdata = dev_get_platdata(dev);
1418 if (!pdata) {
1419 pdata = ads7846_get_props(dev);
1420 if (IS_ERR(pdata))
1421 return PTR_ERR(pdata);
1422 }
1423
1424 ts->model = pdata->model ? : 7846;
1425 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1426 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1427 ts->vref_mv = pdata->vref_mv;
1428
1429 if (pdata->debounce_max) {
1430 ts->debounce_max = pdata->debounce_max;
1431 if (ts->debounce_max < 2)
1432 ts->debounce_max = 2;
1433 ts->debounce_tol = pdata->debounce_tol;
1434 ts->debounce_rep = pdata->debounce_rep;
1435 ts->filter = ads7846_debounce_filter;
1436 ts->filter_data = ts;
1437 } else {
1438 ts->filter = ads7846_no_filter;
1439 }
1440
1441 err = ads7846_setup_pendown(spi, ts, pdata);
1442 if (err)
1443 return err;
1444
1445 if (pdata->penirq_recheck_delay_usecs)
1446 ts->penirq_recheck_delay_usecs =
1447 pdata->penirq_recheck_delay_usecs;
1448
1449 ts->wait_for_sync = pdata->wait_for_sync;
1450
1451 ts->gpio_hsync = devm_gpiod_get_optional(dev, "ti,hsync", GPIOD_IN);
1452 if (IS_ERR(ts->gpio_hsync))
1453 return PTR_ERR(ts->gpio_hsync);
1454
1455 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
1456 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1457
1458 input_dev->name = ts->name;
1459 input_dev->phys = ts->phys;
1460
1461 input_dev->id.bustype = BUS_SPI;
1462 input_dev->id.product = pdata->model;
1463
1464 input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
1465 input_set_abs_params(input_dev, ABS_X,
1466 pdata->x_min ? : 0,
1467 pdata->x_max ? : MAX_12BIT,
1468 0, 0);
1469 input_set_abs_params(input_dev, ABS_Y,
1470 pdata->y_min ? : 0,
1471 pdata->y_max ? : MAX_12BIT,
1472 0, 0);
1473 if (ts->model != 7845)
1474 input_set_abs_params(input_dev, ABS_PRESSURE,
1475 pdata->pressure_min, pdata->pressure_max, 0, 0);
1476
1477 /*
1478 * Parse common framework properties. Must be done here to ensure the
1479 * correct behaviour in case of using the legacy vendor bindings. The
1480 * general binding value overrides the vendor specific one.
1481 */
1482 touchscreen_parse_properties(ts->input, false, &ts->core_prop);
1483 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0;
1484
1485 /*
1486 * Check if legacy ti,swap-xy binding is used instead of
1487 * touchscreen-swapped-x-y
1488 */
1489 if (!ts->core_prop.swap_x_y && pdata->swap_xy) {
1490 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]);
1491 ts->core_prop.swap_x_y = true;
1492 }
1493
1494 err = ts->setup_spi_msg(ts, pdata);
1495 if (err)
1496 return err;
1497
1498 ts->reg = devm_regulator_get(dev, "vcc");
1499 if (IS_ERR(ts->reg)) {
1500 err = PTR_ERR(ts->reg);
1501 dev_err(dev, "unable to get regulator: %d\n", err);
1502 return err;
1503 }
1504
1505 err = regulator_enable(ts->reg);
1506 if (err) {
1507 dev_err(dev, "unable to enable regulator: %d\n", err);
1508 return err;
1509 }
1510
1511 err = devm_add_action_or_reset(dev, ads7846_regulator_disable, ts->reg);
1512 if (err)
1513 return err;
1514
1515 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1516 irq_flags |= IRQF_ONESHOT;
1517
1518 err = devm_request_threaded_irq(dev, spi->irq,
1519 ads7846_hard_irq, ads7846_irq,
1520 irq_flags, dev->driver->name, ts);
1521 if (err && err != -EPROBE_DEFER && !pdata->irq_flags) {
1522 dev_info(dev,
1523 "trying pin change workaround on irq %d\n", spi->irq);
1524 irq_flags |= IRQF_TRIGGER_RISING;
1525 err = devm_request_threaded_irq(dev, spi->irq,
1526 ads7846_hard_irq, ads7846_irq,
1527 irq_flags, dev->driver->name,
1528 ts);
1529 }
1530
1531 if (err) {
1532 dev_dbg(dev, "irq %d busy?\n", spi->irq);
1533 return err;
1534 }
1535
1536 err = ads784x_hwmon_register(spi, ts);
1537 if (err)
1538 return err;
1539
1540 dev_info(dev, "touchscreen, irq %d\n", spi->irq);
1541
1542 /*
1543 * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1544 * the touchscreen, in case it's not connected.
1545 */
1546 if (ts->model == 7845)
1547 ads7845_read12_ser(dev, PWRDOWN);
1548 else
1549 (void) ads7846_read12_ser(dev, READ_12BIT_SER(vaux));
1550
1551 err = input_register_device(input_dev);
1552 if (err)
1553 return err;
1554
1555 device_init_wakeup(dev, pdata->wakeup);
1556
1557 /*
1558 * If device does not carry platform data we must have allocated it
1559 * when parsing DT data.
1560 */
1561 if (!dev_get_platdata(dev))
1562 devm_kfree(dev, (void *)pdata);
1563
1564 return 0;
1565}
1566
1567static void ads7846_remove(struct spi_device *spi)
1568{
1569 struct ads7846 *ts = spi_get_drvdata(spi);
1570
1571 ads7846_stop(ts);
1572}
1573
1574static struct spi_driver ads7846_driver = {
1575 .driver = {
1576 .name = "ads7846",
1577 .dev_groups = ads784x_groups,
1578 .pm = pm_sleep_ptr(&ads7846_pm),
1579 .of_match_table = ads7846_dt_ids,
1580 },
1581 .probe = ads7846_probe,
1582 .remove = ads7846_remove,
1583 .id_table = ads7846_spi_ids,
1584};
1585
1586module_spi_driver(ads7846_driver);
1587
1588MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1589MODULE_LICENSE("GPL");