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 #include <asm/unaligned.h>
37
38 /*
39 * This code has been heavily tested on a Nokia 770, and lightly
40 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
41 * TSC2046 is just newer ads7846 silicon.
42 * Support for ads7843 tested on Atmel at91sam926x-EK.
43 * Support for ads7845 has only been stubbed in.
44 * Support for Analog Devices AD7873 and AD7843 tested.
45 *
46 * IRQ handling needs a workaround because of a shortcoming in handling
47 * edge triggered IRQs on some platforms like the OMAP1/2. These
48 * platforms don't handle the ARM lazy IRQ disabling properly, thus we
49 * have to maintain our own SW IRQ disabled status. This should be
50 * removed as soon as the affected platform's IRQ handling is fixed.
51 *
52 * App note sbaa036 talks in more detail about accurate sampling...
53 * that ought to help in situations like LCDs inducing noise (which
54 * can also be helped by using synch signals) and more generally.
55 * This driver tries to utilize the measures described in the app
56 * note. The strength of filtering can be set in the board-* specific
57 * files.
58 */
59
60 #define TS_POLL_DELAY 1 /* ms delay before the first sample */
61 #define TS_POLL_PERIOD 5 /* ms delay between samples */
62
63 /* this driver doesn't aim at the peak continuous sample rate */
64 #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
65
66 struct ts_event {
67 /*
68 * For portability, we can't read 12 bit values using SPI (which
69 * would make the controller deliver them as native byte order u16
70 * with msbs zeroed). Instead, we read them as two 8-bit values,
71 * *** WHICH NEED BYTESWAPPING *** and range adjustment.
72 */
73 u16 x;
74 u16 y;
75 u16 z1, z2;
76 bool ignore;
77 u8 x_buf[3];
78 u8 y_buf[3];
79 };
80
81 /*
82 * We allocate this separately to avoid cache line sharing issues when
83 * driver is used with DMA-based SPI controllers (like atmel_spi) on
84 * systems where main memory is not DMA-coherent (most non-x86 boards).
85 */
86 struct ads7846_packet {
87 u8 read_x, read_y, read_z1, read_z2, pwrdown;
88 u16 dummy; /* for the pwrdown read */
89 struct ts_event tc;
90 /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */
91 u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
92 };
93
94 struct 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 #if IS_ENABLED(CONFIG_HWMON)
103 struct device *hwmon;
104 #endif
105
106 u16 model;
107 u16 vref_mv;
108 u16 vref_delay_usecs;
109 u16 x_plate_ohms;
110 u16 pressure_max;
111
112 bool swap_xy;
113 bool use_internal;
114
115 struct ads7846_packet *packet;
116
117 struct spi_transfer xfer[18];
118 struct spi_message msg[5];
119 int msg_count;
120 wait_queue_head_t wait;
121
122 bool pendown;
123
124 int read_cnt;
125 int read_rep;
126 int last_read;
127
128 u16 debounce_max;
129 u16 debounce_tol;
130 u16 debounce_rep;
131
132 u16 penirq_recheck_delay_usecs;
133
134 struct touchscreen_properties core_prop;
135
136 struct mutex lock;
137 bool stopped; /* P: lock */
138 bool disabled; /* P: lock */
139 bool suspended; /* P: lock */
140
141 int (*filter)(void *data, int data_idx, int *val);
142 void *filter_data;
143 void (*filter_cleanup)(void *data);
144 int (*get_pendown_state)(void);
145 int gpio_pendown;
146
147 void (*wait_for_sync)(void);
148 };
149
150 /* leave chip selected when we're done, for quicker re-select? */
151 #if 0
152 #define CS_CHANGE(xfer) ((xfer).cs_change = 1)
153 #else
154 #define CS_CHANGE(xfer) ((xfer).cs_change = 0)
155 #endif
156
157 /*--------------------------------------------------------------------------*/
158
159 /* The ADS7846 has touchscreen and other sensors.
160 * Earlier ads784x chips are somewhat compatible.
161 */
162 #define ADS_START (1 << 7)
163 #define ADS_A2A1A0_d_y (1 << 4) /* differential */
164 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */
165 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */
166 #define ADS_A2A1A0_d_x (5 << 4) /* differential */
167 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */
168 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */
169 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */
170 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */
171 #define ADS_8_BIT (1 << 3)
172 #define ADS_12_BIT (0 << 3)
173 #define ADS_SER (1 << 2) /* non-differential */
174 #define ADS_DFR (0 << 2) /* differential */
175 #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */
176 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */
177 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */
178 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */
179
180 #define MAX_12BIT ((1<<12)-1)
181
182 /* leave ADC powered up (disables penirq) between differential samples */
183 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
184 | ADS_12_BIT | ADS_DFR | \
185 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
186
187 #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref))
188 #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref))
189 #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref))
190
191 #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref))
192 #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */
193
194 /* single-ended samples need to first power up reference voltage;
195 * we leave both ADC and VREF powered
196 */
197 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
198 | ADS_12_BIT | ADS_SER)
199
200 #define REF_ON (READ_12BIT_DFR(x, 1, 1))
201 #define REF_OFF (READ_12BIT_DFR(y, 0, 0))
202
get_pendown_state(struct ads7846 * ts)203 static int get_pendown_state(struct ads7846 *ts)
204 {
205 if (ts->get_pendown_state)
206 return ts->get_pendown_state();
207
208 return !gpio_get_value(ts->gpio_pendown);
209 }
210
ads7846_report_pen_up(struct ads7846 * ts)211 static void ads7846_report_pen_up(struct ads7846 *ts)
212 {
213 struct input_dev *input = ts->input;
214
215 input_report_key(input, BTN_TOUCH, 0);
216 input_report_abs(input, ABS_PRESSURE, 0);
217 input_sync(input);
218
219 ts->pendown = false;
220 dev_vdbg(&ts->spi->dev, "UP\n");
221 }
222
223 /* Must be called with ts->lock held */
ads7846_stop(struct ads7846 * ts)224 static void ads7846_stop(struct ads7846 *ts)
225 {
226 if (!ts->disabled && !ts->suspended) {
227 /* Signal IRQ thread to stop polling and disable the handler. */
228 ts->stopped = true;
229 mb();
230 wake_up(&ts->wait);
231 disable_irq(ts->spi->irq);
232 }
233 }
234
235 /* Must be called with ts->lock held */
ads7846_restart(struct ads7846 * ts)236 static void ads7846_restart(struct ads7846 *ts)
237 {
238 if (!ts->disabled && !ts->suspended) {
239 /* Check if pen was released since last stop */
240 if (ts->pendown && !get_pendown_state(ts))
241 ads7846_report_pen_up(ts);
242
243 /* Tell IRQ thread that it may poll the device. */
244 ts->stopped = false;
245 mb();
246 enable_irq(ts->spi->irq);
247 }
248 }
249
250 /* Must be called with ts->lock held */
__ads7846_disable(struct ads7846 * ts)251 static void __ads7846_disable(struct ads7846 *ts)
252 {
253 ads7846_stop(ts);
254 regulator_disable(ts->reg);
255
256 /*
257 * We know the chip's in low power mode since we always
258 * leave it that way after every request
259 */
260 }
261
262 /* Must be called with ts->lock held */
__ads7846_enable(struct ads7846 * ts)263 static void __ads7846_enable(struct ads7846 *ts)
264 {
265 int error;
266
267 error = regulator_enable(ts->reg);
268 if (error != 0)
269 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error);
270
271 ads7846_restart(ts);
272 }
273
ads7846_disable(struct ads7846 * ts)274 static void ads7846_disable(struct ads7846 *ts)
275 {
276 mutex_lock(&ts->lock);
277
278 if (!ts->disabled) {
279
280 if (!ts->suspended)
281 __ads7846_disable(ts);
282
283 ts->disabled = true;
284 }
285
286 mutex_unlock(&ts->lock);
287 }
288
ads7846_enable(struct ads7846 * ts)289 static void ads7846_enable(struct ads7846 *ts)
290 {
291 mutex_lock(&ts->lock);
292
293 if (ts->disabled) {
294
295 ts->disabled = false;
296
297 if (!ts->suspended)
298 __ads7846_enable(ts);
299 }
300
301 mutex_unlock(&ts->lock);
302 }
303
304 /*--------------------------------------------------------------------------*/
305
306 /*
307 * Non-touchscreen sensors only use single-ended conversions.
308 * The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
309 * ads7846 lets that pin be unconnected, to use internal vREF.
310 */
311
312 struct ser_req {
313 u8 ref_on;
314 u8 command;
315 u8 ref_off;
316 u16 scratch;
317 struct spi_message msg;
318 struct spi_transfer xfer[6];
319 /*
320 * DMA (thus cache coherency maintenance) requires the
321 * transfer buffers to live in their own cache lines.
322 */
323 __be16 sample ____cacheline_aligned;
324 };
325
326 struct ads7845_ser_req {
327 u8 command[3];
328 struct spi_message msg;
329 struct spi_transfer xfer[2];
330 /*
331 * DMA (thus cache coherency maintenance) requires the
332 * transfer buffers to live in their own cache lines.
333 */
334 u8 sample[3] ____cacheline_aligned;
335 };
336
ads7846_read12_ser(struct device * dev,unsigned command)337 static int ads7846_read12_ser(struct device *dev, unsigned command)
338 {
339 struct spi_device *spi = to_spi_device(dev);
340 struct ads7846 *ts = dev_get_drvdata(dev);
341 struct ser_req *req;
342 int status;
343
344 req = kzalloc(sizeof *req, GFP_KERNEL);
345 if (!req)
346 return -ENOMEM;
347
348 spi_message_init(&req->msg);
349
350 /* maybe turn on internal vREF, and let it settle */
351 if (ts->use_internal) {
352 req->ref_on = REF_ON;
353 req->xfer[0].tx_buf = &req->ref_on;
354 req->xfer[0].len = 1;
355 spi_message_add_tail(&req->xfer[0], &req->msg);
356
357 req->xfer[1].rx_buf = &req->scratch;
358 req->xfer[1].len = 2;
359
360 /* for 1uF, settle for 800 usec; no cap, 100 usec. */
361 req->xfer[1].delay_usecs = ts->vref_delay_usecs;
362 spi_message_add_tail(&req->xfer[1], &req->msg);
363
364 /* Enable reference voltage */
365 command |= ADS_PD10_REF_ON;
366 }
367
368 /* Enable ADC in every case */
369 command |= ADS_PD10_ADC_ON;
370
371 /* take sample */
372 req->command = (u8) command;
373 req->xfer[2].tx_buf = &req->command;
374 req->xfer[2].len = 1;
375 spi_message_add_tail(&req->xfer[2], &req->msg);
376
377 req->xfer[3].rx_buf = &req->sample;
378 req->xfer[3].len = 2;
379 spi_message_add_tail(&req->xfer[3], &req->msg);
380
381 /* REVISIT: take a few more samples, and compare ... */
382
383 /* converter in low power mode & enable PENIRQ */
384 req->ref_off = PWRDOWN;
385 req->xfer[4].tx_buf = &req->ref_off;
386 req->xfer[4].len = 1;
387 spi_message_add_tail(&req->xfer[4], &req->msg);
388
389 req->xfer[5].rx_buf = &req->scratch;
390 req->xfer[5].len = 2;
391 CS_CHANGE(req->xfer[5]);
392 spi_message_add_tail(&req->xfer[5], &req->msg);
393
394 mutex_lock(&ts->lock);
395 ads7846_stop(ts);
396 status = spi_sync(spi, &req->msg);
397 ads7846_restart(ts);
398 mutex_unlock(&ts->lock);
399
400 if (status == 0) {
401 /* on-wire is a must-ignore bit, a BE12 value, then padding */
402 status = be16_to_cpu(req->sample);
403 status = status >> 3;
404 status &= 0x0fff;
405 }
406
407 kfree(req);
408 return status;
409 }
410
ads7845_read12_ser(struct device * dev,unsigned command)411 static int ads7845_read12_ser(struct device *dev, unsigned command)
412 {
413 struct spi_device *spi = to_spi_device(dev);
414 struct ads7846 *ts = dev_get_drvdata(dev);
415 struct ads7845_ser_req *req;
416 int status;
417
418 req = kzalloc(sizeof *req, GFP_KERNEL);
419 if (!req)
420 return -ENOMEM;
421
422 spi_message_init(&req->msg);
423
424 req->command[0] = (u8) command;
425 req->xfer[0].tx_buf = req->command;
426 req->xfer[0].rx_buf = req->sample;
427 req->xfer[0].len = 3;
428 spi_message_add_tail(&req->xfer[0], &req->msg);
429
430 mutex_lock(&ts->lock);
431 ads7846_stop(ts);
432 status = spi_sync(spi, &req->msg);
433 ads7846_restart(ts);
434 mutex_unlock(&ts->lock);
435
436 if (status == 0) {
437 /* BE12 value, then padding */
438 status = get_unaligned_be16(&req->sample[1]);
439 status = status >> 3;
440 status &= 0x0fff;
441 }
442
443 kfree(req);
444 return status;
445 }
446
447 #if IS_ENABLED(CONFIG_HWMON)
448
449 #define SHOW(name, var, adjust) static ssize_t \
450 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
451 { \
452 struct ads7846 *ts = dev_get_drvdata(dev); \
453 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \
454 READ_12BIT_SER(var)); \
455 if (v < 0) \
456 return v; \
457 return sprintf(buf, "%u\n", adjust(ts, v)); \
458 } \
459 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
460
461
462 /* Sysfs conventions report temperatures in millidegrees Celsius.
463 * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
464 * accuracy scheme without calibration data. For now we won't try either;
465 * userspace sees raw sensor values, and must scale/calibrate appropriately.
466 */
null_adjust(struct ads7846 * ts,ssize_t v)467 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
468 {
469 return v;
470 }
471
SHOW(temp0,temp0,null_adjust)472 SHOW(temp0, temp0, null_adjust) /* temp1_input */
473 SHOW(temp1, temp1, null_adjust) /* temp2_input */
474
475
476 /* sysfs conventions report voltages in millivolts. We can convert voltages
477 * if we know vREF. userspace may need to scale vAUX to match the board's
478 * external resistors; we assume that vBATT only uses the internal ones.
479 */
480 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
481 {
482 unsigned retval = v;
483
484 /* external resistors may scale vAUX into 0..vREF */
485 retval *= ts->vref_mv;
486 retval = retval >> 12;
487
488 return retval;
489 }
490
vbatt_adjust(struct ads7846 * ts,ssize_t v)491 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
492 {
493 unsigned retval = vaux_adjust(ts, v);
494
495 /* ads7846 has a resistor ladder to scale this signal down */
496 if (ts->model == 7846)
497 retval *= 4;
498
499 return retval;
500 }
501
SHOW(in0_input,vaux,vaux_adjust)502 SHOW(in0_input, vaux, vaux_adjust)
503 SHOW(in1_input, vbatt, vbatt_adjust)
504
505 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr,
506 int index)
507 {
508 struct device *dev = container_of(kobj, struct device, kobj);
509 struct ads7846 *ts = dev_get_drvdata(dev);
510
511 if (ts->model == 7843 && index < 2) /* in0, in1 */
512 return 0;
513 if (ts->model == 7845 && index != 2) /* in0 */
514 return 0;
515
516 return attr->mode;
517 }
518
519 static struct attribute *ads7846_attributes[] = {
520 &dev_attr_temp0.attr, /* 0 */
521 &dev_attr_temp1.attr, /* 1 */
522 &dev_attr_in0_input.attr, /* 2 */
523 &dev_attr_in1_input.attr, /* 3 */
524 NULL,
525 };
526
527 static const struct attribute_group ads7846_attr_group = {
528 .attrs = ads7846_attributes,
529 .is_visible = ads7846_is_visible,
530 };
531 __ATTRIBUTE_GROUPS(ads7846_attr);
532
ads784x_hwmon_register(struct spi_device * spi,struct ads7846 * ts)533 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
534 {
535 /* hwmon sensors need a reference voltage */
536 switch (ts->model) {
537 case 7846:
538 if (!ts->vref_mv) {
539 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
540 ts->vref_mv = 2500;
541 ts->use_internal = true;
542 }
543 break;
544 case 7845:
545 case 7843:
546 if (!ts->vref_mv) {
547 dev_warn(&spi->dev,
548 "external vREF for ADS%d not specified\n",
549 ts->model);
550 return 0;
551 }
552 break;
553 }
554
555 ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias,
556 ts, ads7846_attr_groups);
557
558 return PTR_ERR_OR_ZERO(ts->hwmon);
559 }
560
ads784x_hwmon_unregister(struct spi_device * spi,struct ads7846 * ts)561 static void ads784x_hwmon_unregister(struct spi_device *spi,
562 struct ads7846 *ts)
563 {
564 if (ts->hwmon)
565 hwmon_device_unregister(ts->hwmon);
566 }
567
568 #else
ads784x_hwmon_register(struct spi_device * spi,struct ads7846 * ts)569 static inline int ads784x_hwmon_register(struct spi_device *spi,
570 struct ads7846 *ts)
571 {
572 return 0;
573 }
574
ads784x_hwmon_unregister(struct spi_device * spi,struct ads7846 * ts)575 static inline void ads784x_hwmon_unregister(struct spi_device *spi,
576 struct ads7846 *ts)
577 {
578 }
579 #endif
580
ads7846_pen_down_show(struct device * dev,struct device_attribute * attr,char * buf)581 static ssize_t ads7846_pen_down_show(struct device *dev,
582 struct device_attribute *attr, char *buf)
583 {
584 struct ads7846 *ts = dev_get_drvdata(dev);
585
586 return sprintf(buf, "%u\n", ts->pendown);
587 }
588
589 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
590
ads7846_disable_show(struct device * dev,struct device_attribute * attr,char * buf)591 static ssize_t ads7846_disable_show(struct device *dev,
592 struct device_attribute *attr, char *buf)
593 {
594 struct ads7846 *ts = dev_get_drvdata(dev);
595
596 return sprintf(buf, "%u\n", ts->disabled);
597 }
598
ads7846_disable_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)599 static ssize_t ads7846_disable_store(struct device *dev,
600 struct device_attribute *attr,
601 const char *buf, size_t count)
602 {
603 struct ads7846 *ts = dev_get_drvdata(dev);
604 unsigned int i;
605 int err;
606
607 err = kstrtouint(buf, 10, &i);
608 if (err)
609 return err;
610
611 if (i)
612 ads7846_disable(ts);
613 else
614 ads7846_enable(ts);
615
616 return count;
617 }
618
619 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
620
621 static struct attribute *ads784x_attributes[] = {
622 &dev_attr_pen_down.attr,
623 &dev_attr_disable.attr,
624 NULL,
625 };
626
627 static const struct attribute_group ads784x_attr_group = {
628 .attrs = ads784x_attributes,
629 };
630
631 /*--------------------------------------------------------------------------*/
632
null_wait_for_sync(void)633 static void null_wait_for_sync(void)
634 {
635 }
636
ads7846_debounce_filter(void * ads,int data_idx,int * val)637 static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
638 {
639 struct ads7846 *ts = ads;
640
641 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
642 /* Start over collecting consistent readings. */
643 ts->read_rep = 0;
644 /*
645 * Repeat it, if this was the first read or the read
646 * wasn't consistent enough.
647 */
648 if (ts->read_cnt < ts->debounce_max) {
649 ts->last_read = *val;
650 ts->read_cnt++;
651 return ADS7846_FILTER_REPEAT;
652 } else {
653 /*
654 * Maximum number of debouncing reached and still
655 * not enough number of consistent readings. Abort
656 * the whole sample, repeat it in the next sampling
657 * period.
658 */
659 ts->read_cnt = 0;
660 return ADS7846_FILTER_IGNORE;
661 }
662 } else {
663 if (++ts->read_rep > ts->debounce_rep) {
664 /*
665 * Got a good reading for this coordinate,
666 * go for the next one.
667 */
668 ts->read_cnt = 0;
669 ts->read_rep = 0;
670 return ADS7846_FILTER_OK;
671 } else {
672 /* Read more values that are consistent. */
673 ts->read_cnt++;
674 return ADS7846_FILTER_REPEAT;
675 }
676 }
677 }
678
ads7846_no_filter(void * ads,int data_idx,int * val)679 static int ads7846_no_filter(void *ads, int data_idx, int *val)
680 {
681 return ADS7846_FILTER_OK;
682 }
683
ads7846_get_value(struct ads7846 * ts,struct spi_message * m)684 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
685 {
686 int value;
687 struct spi_transfer *t =
688 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
689
690 if (ts->model == 7845) {
691 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1]));
692 } else {
693 /*
694 * adjust: on-wire is a must-ignore bit, a BE12 value, then
695 * padding; built from two 8 bit values written msb-first.
696 */
697 value = be16_to_cpup((__be16 *)t->rx_buf);
698 }
699
700 /* enforce ADC output is 12 bits width */
701 return (value >> 3) & 0xfff;
702 }
703
ads7846_update_value(struct spi_message * m,int val)704 static void ads7846_update_value(struct spi_message *m, int val)
705 {
706 struct spi_transfer *t =
707 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
708
709 *(u16 *)t->rx_buf = val;
710 }
711
ads7846_read_state(struct ads7846 * ts)712 static void ads7846_read_state(struct ads7846 *ts)
713 {
714 struct ads7846_packet *packet = ts->packet;
715 struct spi_message *m;
716 int msg_idx = 0;
717 int val;
718 int action;
719 int error;
720
721 while (msg_idx < ts->msg_count) {
722
723 ts->wait_for_sync();
724
725 m = &ts->msg[msg_idx];
726 error = spi_sync(ts->spi, m);
727 if (error) {
728 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
729 packet->tc.ignore = true;
730 return;
731 }
732
733 /*
734 * Last message is power down request, no need to convert
735 * or filter the value.
736 */
737 if (msg_idx < ts->msg_count - 1) {
738
739 val = ads7846_get_value(ts, m);
740
741 action = ts->filter(ts->filter_data, msg_idx, &val);
742 switch (action) {
743 case ADS7846_FILTER_REPEAT:
744 continue;
745
746 case ADS7846_FILTER_IGNORE:
747 packet->tc.ignore = true;
748 msg_idx = ts->msg_count - 1;
749 continue;
750
751 case ADS7846_FILTER_OK:
752 ads7846_update_value(m, val);
753 packet->tc.ignore = false;
754 msg_idx++;
755 break;
756
757 default:
758 BUG();
759 }
760 } else {
761 msg_idx++;
762 }
763 }
764 }
765
ads7846_report_state(struct ads7846 * ts)766 static void ads7846_report_state(struct ads7846 *ts)
767 {
768 struct ads7846_packet *packet = ts->packet;
769 unsigned int Rt;
770 u16 x, y, z1, z2;
771
772 /*
773 * ads7846_get_value() does in-place conversion (including byte swap)
774 * from on-the-wire format as part of debouncing to get stable
775 * readings.
776 */
777 if (ts->model == 7845) {
778 x = *(u16 *)packet->tc.x_buf;
779 y = *(u16 *)packet->tc.y_buf;
780 z1 = 0;
781 z2 = 0;
782 } else {
783 x = packet->tc.x;
784 y = packet->tc.y;
785 z1 = packet->tc.z1;
786 z2 = packet->tc.z2;
787 }
788
789 /* range filtering */
790 if (x == MAX_12BIT)
791 x = 0;
792
793 if (ts->model == 7843 || ts->model == 7845) {
794 Rt = ts->pressure_max / 2;
795 } else if (likely(x && z1)) {
796 /* compute touch pressure resistance using equation #2 */
797 Rt = z2;
798 Rt -= z1;
799 Rt *= ts->x_plate_ohms;
800 Rt = DIV_ROUND_CLOSEST(Rt, 16);
801 Rt *= x;
802 Rt /= z1;
803 Rt = DIV_ROUND_CLOSEST(Rt, 256);
804 } else {
805 Rt = 0;
806 }
807
808 /*
809 * Sample found inconsistent by debouncing or pressure is beyond
810 * the maximum. Don't report it to user space, repeat at least
811 * once more the measurement
812 */
813 if (packet->tc.ignore || Rt > ts->pressure_max) {
814 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
815 packet->tc.ignore, Rt);
816 return;
817 }
818
819 /*
820 * Maybe check the pendown state before reporting. This discards
821 * false readings when the pen is lifted.
822 */
823 if (ts->penirq_recheck_delay_usecs) {
824 udelay(ts->penirq_recheck_delay_usecs);
825 if (!get_pendown_state(ts))
826 Rt = 0;
827 }
828
829 /*
830 * NOTE: We can't rely on the pressure to determine the pen down
831 * state, even this controller has a pressure sensor. The pressure
832 * value can fluctuate for quite a while after lifting the pen and
833 * in some cases may not even settle at the expected value.
834 *
835 * The only safe way to check for the pen up condition is in the
836 * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
837 */
838 if (Rt) {
839 struct input_dev *input = ts->input;
840
841 if (!ts->pendown) {
842 input_report_key(input, BTN_TOUCH, 1);
843 ts->pendown = true;
844 dev_vdbg(&ts->spi->dev, "DOWN\n");
845 }
846
847 touchscreen_report_pos(input, &ts->core_prop, x, y, false);
848 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
849
850 input_sync(input);
851 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
852 }
853 }
854
ads7846_hard_irq(int irq,void * handle)855 static irqreturn_t ads7846_hard_irq(int irq, void *handle)
856 {
857 struct ads7846 *ts = handle;
858
859 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
860 }
861
862
ads7846_irq(int irq,void * handle)863 static irqreturn_t ads7846_irq(int irq, void *handle)
864 {
865 struct ads7846 *ts = handle;
866
867 /* Start with a small delay before checking pendown state */
868 msleep(TS_POLL_DELAY);
869
870 while (!ts->stopped && get_pendown_state(ts)) {
871
872 /* pen is down, continue with the measurement */
873 ads7846_read_state(ts);
874
875 if (!ts->stopped)
876 ads7846_report_state(ts);
877
878 wait_event_timeout(ts->wait, ts->stopped,
879 msecs_to_jiffies(TS_POLL_PERIOD));
880 }
881
882 if (ts->pendown && !ts->stopped)
883 ads7846_report_pen_up(ts);
884
885 return IRQ_HANDLED;
886 }
887
ads7846_suspend(struct device * dev)888 static 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
ads7846_resume(struct device * dev)910 static 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
932 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
933
ads7846_setup_pendown(struct spi_device * spi,struct ads7846 * ts,const struct ads7846_platform_data * pdata)934 static 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 */
ads7846_setup_spi_msg(struct ads7846 * ts,const struct ads7846_platform_data * pdata)976 static 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
1176 static 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 };
1184 MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1185
ads7846_probe_dt(struct device * dev)1186 static 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 u32 value;
1192
1193 if (!node) {
1194 dev_err(dev, "Device does not have associated DT data\n");
1195 return ERR_PTR(-EINVAL);
1196 }
1197
1198 match = of_match_device(ads7846_dt_ids, dev);
1199 if (!match) {
1200 dev_err(dev, "Unknown device model\n");
1201 return ERR_PTR(-EINVAL);
1202 }
1203
1204 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1205 if (!pdata)
1206 return ERR_PTR(-ENOMEM);
1207
1208 pdata->model = (unsigned long)match->data;
1209
1210 of_property_read_u16(node, "ti,vref-delay-usecs",
1211 &pdata->vref_delay_usecs);
1212 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
1213 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
1214
1215 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
1216
1217 of_property_read_u16(node, "ti,settle-delay-usec",
1218 &pdata->settle_delay_usecs);
1219 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
1220 &pdata->penirq_recheck_delay_usecs);
1221
1222 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1223 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1224
1225 of_property_read_u16(node, "ti,x-min", &pdata->x_min);
1226 of_property_read_u16(node, "ti,y-min", &pdata->y_min);
1227 of_property_read_u16(node, "ti,x-max", &pdata->x_max);
1228 of_property_read_u16(node, "ti,y-max", &pdata->y_max);
1229
1230 /*
1231 * touchscreen-max-pressure gets parsed during
1232 * touchscreen_parse_properties()
1233 */
1234 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1235 if (!of_property_read_u32(node, "touchscreen-min-pressure", &value))
1236 pdata->pressure_min = (u16) value;
1237 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1238
1239 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1240 if (!of_property_read_u32(node, "touchscreen-average-samples", &value))
1241 pdata->debounce_max = (u16) value;
1242 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1243 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1244
1245 of_property_read_u32(node, "ti,pendown-gpio-debounce",
1246 &pdata->gpio_pendown_debounce);
1247
1248 pdata->wakeup = of_property_read_bool(node, "wakeup-source") ||
1249 of_property_read_bool(node, "linux,wakeup");
1250
1251 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1252
1253 return pdata;
1254 }
1255 #else
ads7846_probe_dt(struct device * dev)1256 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1257 {
1258 dev_err(dev, "no platform data defined\n");
1259 return ERR_PTR(-EINVAL);
1260 }
1261 #endif
1262
ads7846_probe(struct spi_device * spi)1263 static int ads7846_probe(struct spi_device *spi)
1264 {
1265 const struct ads7846_platform_data *pdata;
1266 struct ads7846 *ts;
1267 struct ads7846_packet *packet;
1268 struct input_dev *input_dev;
1269 unsigned long irq_flags;
1270 int err;
1271
1272 if (!spi->irq) {
1273 dev_dbg(&spi->dev, "no IRQ?\n");
1274 return -EINVAL;
1275 }
1276
1277 /* don't exceed max specified sample rate */
1278 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1279 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1280 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1281 return -EINVAL;
1282 }
1283
1284 /*
1285 * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1286 * that even if the hardware can do that, the SPI controller driver
1287 * may not. So we stick to very-portable 8 bit words, both RX and TX.
1288 */
1289 spi->bits_per_word = 8;
1290 spi->mode = SPI_MODE_0;
1291 err = spi_setup(spi);
1292 if (err < 0)
1293 return err;
1294
1295 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1296 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1297 input_dev = input_allocate_device();
1298 if (!ts || !packet || !input_dev) {
1299 err = -ENOMEM;
1300 goto err_free_mem;
1301 }
1302
1303 spi_set_drvdata(spi, ts);
1304
1305 ts->packet = packet;
1306 ts->spi = spi;
1307 ts->input = input_dev;
1308
1309 mutex_init(&ts->lock);
1310 init_waitqueue_head(&ts->wait);
1311
1312 pdata = dev_get_platdata(&spi->dev);
1313 if (!pdata) {
1314 pdata = ads7846_probe_dt(&spi->dev);
1315 if (IS_ERR(pdata)) {
1316 err = PTR_ERR(pdata);
1317 goto err_free_mem;
1318 }
1319 }
1320
1321 ts->model = pdata->model ? : 7846;
1322 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1323 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1324 ts->vref_mv = pdata->vref_mv;
1325
1326 if (pdata->filter != NULL) {
1327 if (pdata->filter_init != NULL) {
1328 err = pdata->filter_init(pdata, &ts->filter_data);
1329 if (err < 0)
1330 goto err_free_mem;
1331 }
1332 ts->filter = pdata->filter;
1333 ts->filter_cleanup = pdata->filter_cleanup;
1334 } else if (pdata->debounce_max) {
1335 ts->debounce_max = pdata->debounce_max;
1336 if (ts->debounce_max < 2)
1337 ts->debounce_max = 2;
1338 ts->debounce_tol = pdata->debounce_tol;
1339 ts->debounce_rep = pdata->debounce_rep;
1340 ts->filter = ads7846_debounce_filter;
1341 ts->filter_data = ts;
1342 } else {
1343 ts->filter = ads7846_no_filter;
1344 }
1345
1346 err = ads7846_setup_pendown(spi, ts, pdata);
1347 if (err)
1348 goto err_cleanup_filter;
1349
1350 if (pdata->penirq_recheck_delay_usecs)
1351 ts->penirq_recheck_delay_usecs =
1352 pdata->penirq_recheck_delay_usecs;
1353
1354 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1355
1356 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1357 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1358
1359 input_dev->name = ts->name;
1360 input_dev->phys = ts->phys;
1361 input_dev->dev.parent = &spi->dev;
1362
1363 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1364 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1365 input_set_abs_params(input_dev, ABS_X,
1366 pdata->x_min ? : 0,
1367 pdata->x_max ? : MAX_12BIT,
1368 0, 0);
1369 input_set_abs_params(input_dev, ABS_Y,
1370 pdata->y_min ? : 0,
1371 pdata->y_max ? : MAX_12BIT,
1372 0, 0);
1373 if (ts->model != 7845)
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
ads7846_remove(struct spi_device * spi)1485 static 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
1519 static 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
1529 module_spi_driver(ads7846_driver);
1530
1531 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1532 MODULE_LICENSE("GPL");
1533 MODULE_ALIAS("spi:ads7846");
1534