1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * ADS7846 based touchscreen and sensor driver
4 *
5 * Copyright (c) 2005 David Brownell
6 * Copyright (c) 2006 Nokia Corporation
7 * Various changes: Imre Deak <imre.deak@nokia.com>
8 *
9 * Using code from:
10 * - corgi_ts.c
11 * Copyright (C) 2004-2005 Richard Purdie
12 * - omap_ts.[hc], ads7846.h, ts_osk.c
13 * Copyright (C) 2002 MontaVista Software
14 * Copyright (C) 2004 Texas Instruments
15 * Copyright (C) 2005 Dirk Behme
16 */
17 #include <linux/types.h>
18 #include <linux/hwmon.h>
19 #include <linux/err.h>
20 #include <linux/sched.h>
21 #include <linux/delay.h>
22 #include <linux/input.h>
23 #include <linux/input/touchscreen.h>
24 #include <linux/interrupt.h>
25 #include <linux/slab.h>
26 #include <linux/pm.h>
27 #include <linux/of.h>
28 #include <linux/of_gpio.h>
29 #include <linux/of_device.h>
30 #include <linux/gpio.h>
31 #include <linux/spi/spi.h>
32 #include <linux/spi/ads7846.h>
33 #include <linux/regulator/consumer.h>
34 #include <linux/module.h>
35 #include <asm/irq.h>
36
37 /*
38 * This code has been heavily tested on a Nokia 770, and lightly
39 * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
40 * TSC2046 is just newer ads7846 silicon.
41 * Support for ads7843 tested on Atmel at91sam926x-EK.
42 * Support for ads7845 has only been stubbed in.
43 * Support for Analog Devices AD7873 and AD7843 tested.
44 *
45 * IRQ handling needs a workaround because of a shortcoming in handling
46 * edge triggered IRQs on some platforms like the OMAP1/2. These
47 * platforms don't handle the ARM lazy IRQ disabling properly, thus we
48 * have to maintain our own SW IRQ disabled status. This should be
49 * removed as soon as the affected platform's IRQ handling is fixed.
50 *
51 * App note sbaa036 talks in more detail about accurate sampling...
52 * that ought to help in situations like LCDs inducing noise (which
53 * can also be helped by using synch signals) and more generally.
54 * This driver tries to utilize the measures described in the app
55 * note. The strength of filtering can be set in the board-* specific
56 * files.
57 */
58
59 #define TS_POLL_DELAY 1 /* ms delay before the first sample */
60 #define TS_POLL_PERIOD 5 /* ms delay between samples */
61
62 /* this driver doesn't aim at the peak continuous sample rate */
63 #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
64
65 struct ts_event {
66 /*
67 * For portability, we can't read 12 bit values using SPI (which
68 * would make the controller deliver them as native byte order u16
69 * with msbs zeroed). Instead, we read them as two 8-bit values,
70 * *** WHICH NEED BYTESWAPPING *** and range adjustment.
71 */
72 u16 x;
73 u16 y;
74 u16 z1, z2;
75 bool ignore;
76 u8 x_buf[3];
77 u8 y_buf[3];
78 };
79
80 /*
81 * We allocate this separately to avoid cache line sharing issues when
82 * driver is used with DMA-based SPI controllers (like atmel_spi) on
83 * systems where main memory is not DMA-coherent (most non-x86 boards).
84 */
85 struct ads7846_packet {
86 u8 read_x, read_y, read_z1, read_z2, pwrdown;
87 u16 dummy; /* for the pwrdown read */
88 struct ts_event tc;
89 /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */
90 u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
91 };
92
93 struct ads7846 {
94 struct input_dev *input;
95 char phys[32];
96 char name[32];
97
98 struct spi_device *spi;
99 struct regulator *reg;
100
101 #if IS_ENABLED(CONFIG_HWMON)
102 struct device *hwmon;
103 #endif
104
105 u16 model;
106 u16 vref_mv;
107 u16 vref_delay_usecs;
108 u16 x_plate_ohms;
109 u16 pressure_max;
110
111 bool swap_xy;
112 bool use_internal;
113
114 struct ads7846_packet *packet;
115
116 struct spi_transfer xfer[18];
117 struct spi_message msg[5];
118 int msg_count;
119 wait_queue_head_t wait;
120
121 bool pendown;
122
123 int read_cnt;
124 int read_rep;
125 int last_read;
126
127 u16 debounce_max;
128 u16 debounce_tol;
129 u16 debounce_rep;
130
131 u16 penirq_recheck_delay_usecs;
132
133 struct touchscreen_properties core_prop;
134
135 struct mutex lock;
136 bool stopped; /* P: lock */
137 bool disabled; /* P: lock */
138 bool suspended; /* P: lock */
139
140 int (*filter)(void *data, int data_idx, int *val);
141 void *filter_data;
142 void (*filter_cleanup)(void *data);
143 int (*get_pendown_state)(void);
144 int gpio_pendown;
145
146 void (*wait_for_sync)(void);
147 };
148
149 /* leave chip selected when we're done, for quicker re-select? */
150 #if 0
151 #define CS_CHANGE(xfer) ((xfer).cs_change = 1)
152 #else
153 #define CS_CHANGE(xfer) ((xfer).cs_change = 0)
154 #endif
155
156 /*--------------------------------------------------------------------------*/
157
158 /* The ADS7846 has touchscreen and other sensors.
159 * Earlier ads784x chips are somewhat compatible.
160 */
161 #define ADS_START (1 << 7)
162 #define ADS_A2A1A0_d_y (1 << 4) /* differential */
163 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */
164 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */
165 #define ADS_A2A1A0_d_x (5 << 4) /* differential */
166 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */
167 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */
168 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */
169 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */
170 #define ADS_8_BIT (1 << 3)
171 #define ADS_12_BIT (0 << 3)
172 #define ADS_SER (1 << 2) /* non-differential */
173 #define ADS_DFR (0 << 2) /* differential */
174 #define ADS_PD10_PDOWN (0 << 0) /* low power mode + penirq */
175 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */
176 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */
177 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */
178
179 #define MAX_12BIT ((1<<12)-1)
180
181 /* leave ADC powered up (disables penirq) between differential samples */
182 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
183 | ADS_12_BIT | ADS_DFR | \
184 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
185
186 #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref))
187 #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref))
188 #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref))
189
190 #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref))
191 #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */
192
193 /* single-ended samples need to first power up reference voltage;
194 * we leave both ADC and VREF powered
195 */
196 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
197 | ADS_12_BIT | ADS_SER)
198
199 #define REF_ON (READ_12BIT_DFR(x, 1, 1))
200 #define REF_OFF (READ_12BIT_DFR(y, 0, 0))
201
202 /* Must be called with ts->lock held */
ads7846_stop(struct ads7846 * ts)203 static 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 */
ads7846_restart(struct ads7846 * ts)215 static 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 */
__ads7846_disable(struct ads7846 * ts)226 static 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 */
__ads7846_enable(struct ads7846 * ts)238 static 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
ads7846_disable(struct ads7846 * ts)249 static 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
ads7846_enable(struct ads7846 * ts)264 static 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
287 struct 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
301 struct 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
ads7846_read12_ser(struct device * dev,unsigned command)312 static 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
ads7845_read12_ser(struct device * dev,unsigned command)386 static 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 \
425 name ## _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 } \
434 static 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 */
null_adjust(struct ads7846 * ts,ssize_t v)442 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
443 {
444 return v;
445 }
446
SHOW(temp0,temp0,null_adjust)447 SHOW(temp0, temp0, null_adjust) /* temp1_input */
448 SHOW(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 */
455 static 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
vbatt_adjust(struct ads7846 * ts,ssize_t v)466 static 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
SHOW(in0_input,vaux,vaux_adjust)477 SHOW(in0_input, vaux, vaux_adjust)
478 SHOW(in1_input, vbatt, vbatt_adjust)
479
480 static 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
494 static 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
502 static const struct attribute_group ads7846_attr_group = {
503 .attrs = ads7846_attributes,
504 .is_visible = ads7846_is_visible,
505 };
506 __ATTRIBUTE_GROUPS(ads7846_attr);
507
ads784x_hwmon_register(struct spi_device * spi,struct ads7846 * ts)508 static 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
ads784x_hwmon_unregister(struct spi_device * spi,struct ads7846 * ts)536 static 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
ads784x_hwmon_register(struct spi_device * spi,struct ads7846 * ts)544 static inline int ads784x_hwmon_register(struct spi_device *spi,
545 struct ads7846 *ts)
546 {
547 return 0;
548 }
549
ads784x_hwmon_unregister(struct spi_device * spi,struct ads7846 * ts)550 static inline void ads784x_hwmon_unregister(struct spi_device *spi,
551 struct ads7846 *ts)
552 {
553 }
554 #endif
555
ads7846_pen_down_show(struct device * dev,struct device_attribute * attr,char * buf)556 static 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
564 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
565
ads7846_disable_show(struct device * dev,struct device_attribute * attr,char * buf)566 static 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
ads7846_disable_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)574 static 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
594 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
595
596 static struct attribute *ads784x_attributes[] = {
597 &dev_attr_pen_down.attr,
598 &dev_attr_disable.attr,
599 NULL,
600 };
601
602 static const struct attribute_group ads784x_attr_group = {
603 .attrs = ads784x_attributes,
604 };
605
606 /*--------------------------------------------------------------------------*/
607
get_pendown_state(struct ads7846 * ts)608 static 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
null_wait_for_sync(void)616 static void null_wait_for_sync(void)
617 {
618 }
619
ads7846_debounce_filter(void * ads,int data_idx,int * val)620 static 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
ads7846_no_filter(void * ads,int data_idx,int * val)662 static int ads7846_no_filter(void *ads, int data_idx, int *val)
663 {
664 return ADS7846_FILTER_OK;
665 }
666
ads7846_get_value(struct ads7846 * ts,struct spi_message * m)667 static 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
ads7846_update_value(struct spi_message * m,int val)687 static 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
ads7846_read_state(struct ads7846 * ts)695 static 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
ads7846_report_state(struct ads7846 * ts)749 static 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->pendown) {
830 input_report_key(input, BTN_TOUCH, 1);
831 ts->pendown = true;
832 dev_vdbg(&ts->spi->dev, "DOWN\n");
833 }
834
835 touchscreen_report_pos(input, &ts->core_prop, x, y, false);
836 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
837
838 input_sync(input);
839 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
840 }
841 }
842
ads7846_hard_irq(int irq,void * handle)843 static irqreturn_t ads7846_hard_irq(int irq, void *handle)
844 {
845 struct ads7846 *ts = handle;
846
847 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
848 }
849
850
ads7846_irq(int irq,void * handle)851 static irqreturn_t ads7846_irq(int irq, void *handle)
852 {
853 struct ads7846 *ts = handle;
854
855 /* Start with a small delay before checking pendown state */
856 msleep(TS_POLL_DELAY);
857
858 while (!ts->stopped && get_pendown_state(ts)) {
859
860 /* pen is down, continue with the measurement */
861 ads7846_read_state(ts);
862
863 if (!ts->stopped)
864 ads7846_report_state(ts);
865
866 wait_event_timeout(ts->wait, ts->stopped,
867 msecs_to_jiffies(TS_POLL_PERIOD));
868 }
869
870 if (ts->pendown && !ts->stopped) {
871 struct input_dev *input = ts->input;
872
873 input_report_key(input, BTN_TOUCH, 0);
874 input_report_abs(input, ABS_PRESSURE, 0);
875 input_sync(input);
876
877 ts->pendown = false;
878 dev_vdbg(&ts->spi->dev, "UP\n");
879 }
880
881 return IRQ_HANDLED;
882 }
883
ads7846_suspend(struct device * dev)884 static int __maybe_unused ads7846_suspend(struct device *dev)
885 {
886 struct ads7846 *ts = dev_get_drvdata(dev);
887
888 mutex_lock(&ts->lock);
889
890 if (!ts->suspended) {
891
892 if (!ts->disabled)
893 __ads7846_disable(ts);
894
895 if (device_may_wakeup(&ts->spi->dev))
896 enable_irq_wake(ts->spi->irq);
897
898 ts->suspended = true;
899 }
900
901 mutex_unlock(&ts->lock);
902
903 return 0;
904 }
905
ads7846_resume(struct device * dev)906 static int __maybe_unused ads7846_resume(struct device *dev)
907 {
908 struct ads7846 *ts = dev_get_drvdata(dev);
909
910 mutex_lock(&ts->lock);
911
912 if (ts->suspended) {
913
914 ts->suspended = false;
915
916 if (device_may_wakeup(&ts->spi->dev))
917 disable_irq_wake(ts->spi->irq);
918
919 if (!ts->disabled)
920 __ads7846_enable(ts);
921 }
922
923 mutex_unlock(&ts->lock);
924
925 return 0;
926 }
927
928 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
929
ads7846_setup_pendown(struct spi_device * spi,struct ads7846 * ts,const struct ads7846_platform_data * pdata)930 static int ads7846_setup_pendown(struct spi_device *spi,
931 struct ads7846 *ts,
932 const struct ads7846_platform_data *pdata)
933 {
934 int err;
935
936 /*
937 * REVISIT when the irq can be triggered active-low, or if for some
938 * reason the touchscreen isn't hooked up, we don't need to access
939 * the pendown state.
940 */
941
942 if (pdata->get_pendown_state) {
943 ts->get_pendown_state = pdata->get_pendown_state;
944 } else if (gpio_is_valid(pdata->gpio_pendown)) {
945
946 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
947 "ads7846_pendown");
948 if (err) {
949 dev_err(&spi->dev,
950 "failed to request/setup pendown GPIO%d: %d\n",
951 pdata->gpio_pendown, err);
952 return err;
953 }
954
955 ts->gpio_pendown = pdata->gpio_pendown;
956
957 if (pdata->gpio_pendown_debounce)
958 gpio_set_debounce(pdata->gpio_pendown,
959 pdata->gpio_pendown_debounce);
960 } else {
961 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
962 return -EINVAL;
963 }
964
965 return 0;
966 }
967
968 /*
969 * Set up the transfers to read touchscreen state; this assumes we
970 * use formula #2 for pressure, not #3.
971 */
ads7846_setup_spi_msg(struct ads7846 * ts,const struct ads7846_platform_data * pdata)972 static void ads7846_setup_spi_msg(struct ads7846 *ts,
973 const struct ads7846_platform_data *pdata)
974 {
975 struct spi_message *m = &ts->msg[0];
976 struct spi_transfer *x = ts->xfer;
977 struct ads7846_packet *packet = ts->packet;
978 int vref = pdata->keep_vref_on;
979
980 if (ts->model == 7873) {
981 /*
982 * The AD7873 is almost identical to the ADS7846
983 * keep VREF off during differential/ratiometric
984 * conversion modes.
985 */
986 ts->model = 7846;
987 vref = 0;
988 }
989
990 ts->msg_count = 1;
991 spi_message_init(m);
992 m->context = ts;
993
994 if (ts->model == 7845) {
995 packet->read_y_cmd[0] = READ_Y(vref);
996 packet->read_y_cmd[1] = 0;
997 packet->read_y_cmd[2] = 0;
998 x->tx_buf = &packet->read_y_cmd[0];
999 x->rx_buf = &packet->tc.y_buf[0];
1000 x->len = 3;
1001 spi_message_add_tail(x, m);
1002 } else {
1003 /* y- still on; turn on only y+ (and ADC) */
1004 packet->read_y = READ_Y(vref);
1005 x->tx_buf = &packet->read_y;
1006 x->len = 1;
1007 spi_message_add_tail(x, m);
1008
1009 x++;
1010 x->rx_buf = &packet->tc.y;
1011 x->len = 2;
1012 spi_message_add_tail(x, m);
1013 }
1014
1015 /*
1016 * The first sample after switching drivers can be low quality;
1017 * optionally discard it, using a second one after the signals
1018 * have had enough time to stabilize.
1019 */
1020 if (pdata->settle_delay_usecs) {
1021 x->delay_usecs = pdata->settle_delay_usecs;
1022
1023 x++;
1024 x->tx_buf = &packet->read_y;
1025 x->len = 1;
1026 spi_message_add_tail(x, m);
1027
1028 x++;
1029 x->rx_buf = &packet->tc.y;
1030 x->len = 2;
1031 spi_message_add_tail(x, m);
1032 }
1033
1034 ts->msg_count++;
1035 m++;
1036 spi_message_init(m);
1037 m->context = ts;
1038
1039 if (ts->model == 7845) {
1040 x++;
1041 packet->read_x_cmd[0] = READ_X(vref);
1042 packet->read_x_cmd[1] = 0;
1043 packet->read_x_cmd[2] = 0;
1044 x->tx_buf = &packet->read_x_cmd[0];
1045 x->rx_buf = &packet->tc.x_buf[0];
1046 x->len = 3;
1047 spi_message_add_tail(x, m);
1048 } else {
1049 /* turn y- off, x+ on, then leave in lowpower */
1050 x++;
1051 packet->read_x = READ_X(vref);
1052 x->tx_buf = &packet->read_x;
1053 x->len = 1;
1054 spi_message_add_tail(x, m);
1055
1056 x++;
1057 x->rx_buf = &packet->tc.x;
1058 x->len = 2;
1059 spi_message_add_tail(x, m);
1060 }
1061
1062 /* ... maybe discard first sample ... */
1063 if (pdata->settle_delay_usecs) {
1064 x->delay_usecs = pdata->settle_delay_usecs;
1065
1066 x++;
1067 x->tx_buf = &packet->read_x;
1068 x->len = 1;
1069 spi_message_add_tail(x, m);
1070
1071 x++;
1072 x->rx_buf = &packet->tc.x;
1073 x->len = 2;
1074 spi_message_add_tail(x, m);
1075 }
1076
1077 /* turn y+ off, x- on; we'll use formula #2 */
1078 if (ts->model == 7846) {
1079 ts->msg_count++;
1080 m++;
1081 spi_message_init(m);
1082 m->context = ts;
1083
1084 x++;
1085 packet->read_z1 = READ_Z1(vref);
1086 x->tx_buf = &packet->read_z1;
1087 x->len = 1;
1088 spi_message_add_tail(x, m);
1089
1090 x++;
1091 x->rx_buf = &packet->tc.z1;
1092 x->len = 2;
1093 spi_message_add_tail(x, m);
1094
1095 /* ... maybe discard first sample ... */
1096 if (pdata->settle_delay_usecs) {
1097 x->delay_usecs = pdata->settle_delay_usecs;
1098
1099 x++;
1100 x->tx_buf = &packet->read_z1;
1101 x->len = 1;
1102 spi_message_add_tail(x, m);
1103
1104 x++;
1105 x->rx_buf = &packet->tc.z1;
1106 x->len = 2;
1107 spi_message_add_tail(x, m);
1108 }
1109
1110 ts->msg_count++;
1111 m++;
1112 spi_message_init(m);
1113 m->context = ts;
1114
1115 x++;
1116 packet->read_z2 = READ_Z2(vref);
1117 x->tx_buf = &packet->read_z2;
1118 x->len = 1;
1119 spi_message_add_tail(x, m);
1120
1121 x++;
1122 x->rx_buf = &packet->tc.z2;
1123 x->len = 2;
1124 spi_message_add_tail(x, m);
1125
1126 /* ... maybe discard first sample ... */
1127 if (pdata->settle_delay_usecs) {
1128 x->delay_usecs = pdata->settle_delay_usecs;
1129
1130 x++;
1131 x->tx_buf = &packet->read_z2;
1132 x->len = 1;
1133 spi_message_add_tail(x, m);
1134
1135 x++;
1136 x->rx_buf = &packet->tc.z2;
1137 x->len = 2;
1138 spi_message_add_tail(x, m);
1139 }
1140 }
1141
1142 /* power down */
1143 ts->msg_count++;
1144 m++;
1145 spi_message_init(m);
1146 m->context = ts;
1147
1148 if (ts->model == 7845) {
1149 x++;
1150 packet->pwrdown_cmd[0] = PWRDOWN;
1151 packet->pwrdown_cmd[1] = 0;
1152 packet->pwrdown_cmd[2] = 0;
1153 x->tx_buf = &packet->pwrdown_cmd[0];
1154 x->len = 3;
1155 } else {
1156 x++;
1157 packet->pwrdown = PWRDOWN;
1158 x->tx_buf = &packet->pwrdown;
1159 x->len = 1;
1160 spi_message_add_tail(x, m);
1161
1162 x++;
1163 x->rx_buf = &packet->dummy;
1164 x->len = 2;
1165 }
1166
1167 CS_CHANGE(*x);
1168 spi_message_add_tail(x, m);
1169 }
1170
1171 #ifdef CONFIG_OF
1172 static const struct of_device_id ads7846_dt_ids[] = {
1173 { .compatible = "ti,tsc2046", .data = (void *) 7846 },
1174 { .compatible = "ti,ads7843", .data = (void *) 7843 },
1175 { .compatible = "ti,ads7845", .data = (void *) 7845 },
1176 { .compatible = "ti,ads7846", .data = (void *) 7846 },
1177 { .compatible = "ti,ads7873", .data = (void *) 7873 },
1178 { }
1179 };
1180 MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1181
ads7846_probe_dt(struct device * dev)1182 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1183 {
1184 struct ads7846_platform_data *pdata;
1185 struct device_node *node = dev->of_node;
1186 const struct of_device_id *match;
1187 u32 value;
1188
1189 if (!node) {
1190 dev_err(dev, "Device does not have associated DT data\n");
1191 return ERR_PTR(-EINVAL);
1192 }
1193
1194 match = of_match_device(ads7846_dt_ids, dev);
1195 if (!match) {
1196 dev_err(dev, "Unknown device model\n");
1197 return ERR_PTR(-EINVAL);
1198 }
1199
1200 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1201 if (!pdata)
1202 return ERR_PTR(-ENOMEM);
1203
1204 pdata->model = (unsigned long)match->data;
1205
1206 of_property_read_u16(node, "ti,vref-delay-usecs",
1207 &pdata->vref_delay_usecs);
1208 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
1209 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
1210
1211 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
1212
1213 of_property_read_u16(node, "ti,settle-delay-usec",
1214 &pdata->settle_delay_usecs);
1215 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
1216 &pdata->penirq_recheck_delay_usecs);
1217
1218 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1219 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1220
1221 of_property_read_u16(node, "ti,x-min", &pdata->x_min);
1222 of_property_read_u16(node, "ti,y-min", &pdata->y_min);
1223 of_property_read_u16(node, "ti,x-max", &pdata->x_max);
1224 of_property_read_u16(node, "ti,y-max", &pdata->y_max);
1225
1226 /*
1227 * touchscreen-max-pressure gets parsed during
1228 * touchscreen_parse_properties()
1229 */
1230 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1231 if (!of_property_read_u32(node, "touchscreen-min-pressure", &value))
1232 pdata->pressure_min = (u16) value;
1233 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1234
1235 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1236 if (!of_property_read_u32(node, "touchscreen-average-samples", &value))
1237 pdata->debounce_max = (u16) value;
1238 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1239 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1240
1241 of_property_read_u32(node, "ti,pendown-gpio-debounce",
1242 &pdata->gpio_pendown_debounce);
1243
1244 pdata->wakeup = of_property_read_bool(node, "wakeup-source") ||
1245 of_property_read_bool(node, "linux,wakeup");
1246
1247 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1248
1249 return pdata;
1250 }
1251 #else
ads7846_probe_dt(struct device * dev)1252 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1253 {
1254 dev_err(dev, "no platform data defined\n");
1255 return ERR_PTR(-EINVAL);
1256 }
1257 #endif
1258
ads7846_probe(struct spi_device * spi)1259 static int ads7846_probe(struct spi_device *spi)
1260 {
1261 const struct ads7846_platform_data *pdata;
1262 struct ads7846 *ts;
1263 struct ads7846_packet *packet;
1264 struct input_dev *input_dev;
1265 unsigned long irq_flags;
1266 int err;
1267
1268 if (!spi->irq) {
1269 dev_dbg(&spi->dev, "no IRQ?\n");
1270 return -EINVAL;
1271 }
1272
1273 /* don't exceed max specified sample rate */
1274 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1275 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1276 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1277 return -EINVAL;
1278 }
1279
1280 /*
1281 * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1282 * that even if the hardware can do that, the SPI controller driver
1283 * may not. So we stick to very-portable 8 bit words, both RX and TX.
1284 */
1285 spi->bits_per_word = 8;
1286 spi->mode = SPI_MODE_0;
1287 err = spi_setup(spi);
1288 if (err < 0)
1289 return err;
1290
1291 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1292 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1293 input_dev = input_allocate_device();
1294 if (!ts || !packet || !input_dev) {
1295 err = -ENOMEM;
1296 goto err_free_mem;
1297 }
1298
1299 spi_set_drvdata(spi, ts);
1300
1301 ts->packet = packet;
1302 ts->spi = spi;
1303 ts->input = input_dev;
1304
1305 mutex_init(&ts->lock);
1306 init_waitqueue_head(&ts->wait);
1307
1308 pdata = dev_get_platdata(&spi->dev);
1309 if (!pdata) {
1310 pdata = ads7846_probe_dt(&spi->dev);
1311 if (IS_ERR(pdata)) {
1312 err = PTR_ERR(pdata);
1313 goto err_free_mem;
1314 }
1315 }
1316
1317 ts->model = pdata->model ? : 7846;
1318 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1319 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1320 ts->vref_mv = pdata->vref_mv;
1321
1322 if (pdata->filter != NULL) {
1323 if (pdata->filter_init != NULL) {
1324 err = pdata->filter_init(pdata, &ts->filter_data);
1325 if (err < 0)
1326 goto err_free_mem;
1327 }
1328 ts->filter = pdata->filter;
1329 ts->filter_cleanup = pdata->filter_cleanup;
1330 } else if (pdata->debounce_max) {
1331 ts->debounce_max = pdata->debounce_max;
1332 if (ts->debounce_max < 2)
1333 ts->debounce_max = 2;
1334 ts->debounce_tol = pdata->debounce_tol;
1335 ts->debounce_rep = pdata->debounce_rep;
1336 ts->filter = ads7846_debounce_filter;
1337 ts->filter_data = ts;
1338 } else {
1339 ts->filter = ads7846_no_filter;
1340 }
1341
1342 err = ads7846_setup_pendown(spi, ts, pdata);
1343 if (err)
1344 goto err_cleanup_filter;
1345
1346 if (pdata->penirq_recheck_delay_usecs)
1347 ts->penirq_recheck_delay_usecs =
1348 pdata->penirq_recheck_delay_usecs;
1349
1350 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1351
1352 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1353 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1354
1355 input_dev->name = ts->name;
1356 input_dev->phys = ts->phys;
1357 input_dev->dev.parent = &spi->dev;
1358
1359 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1360 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1361 input_set_abs_params(input_dev, ABS_X,
1362 pdata->x_min ? : 0,
1363 pdata->x_max ? : MAX_12BIT,
1364 0, 0);
1365 input_set_abs_params(input_dev, ABS_Y,
1366 pdata->y_min ? : 0,
1367 pdata->y_max ? : MAX_12BIT,
1368 0, 0);
1369 input_set_abs_params(input_dev, ABS_PRESSURE,
1370 pdata->pressure_min, pdata->pressure_max, 0, 0);
1371
1372 /*
1373 * Parse common framework properties. Must be done here to ensure the
1374 * correct behaviour in case of using the legacy vendor bindings. The
1375 * general binding value overrides the vendor specific one.
1376 */
1377 touchscreen_parse_properties(ts->input, false, &ts->core_prop);
1378 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0;
1379
1380 /*
1381 * Check if legacy ti,swap-xy binding is used instead of
1382 * touchscreen-swapped-x-y
1383 */
1384 if (!ts->core_prop.swap_x_y && pdata->swap_xy) {
1385 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]);
1386 ts->core_prop.swap_x_y = true;
1387 }
1388
1389 ads7846_setup_spi_msg(ts, pdata);
1390
1391 ts->reg = regulator_get(&spi->dev, "vcc");
1392 if (IS_ERR(ts->reg)) {
1393 err = PTR_ERR(ts->reg);
1394 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1395 goto err_free_gpio;
1396 }
1397
1398 err = regulator_enable(ts->reg);
1399 if (err) {
1400 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1401 goto err_put_regulator;
1402 }
1403
1404 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1405 irq_flags |= IRQF_ONESHOT;
1406
1407 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1408 irq_flags, spi->dev.driver->name, ts);
1409 if (err && !pdata->irq_flags) {
1410 dev_info(&spi->dev,
1411 "trying pin change workaround on irq %d\n", spi->irq);
1412 irq_flags |= IRQF_TRIGGER_RISING;
1413 err = request_threaded_irq(spi->irq,
1414 ads7846_hard_irq, ads7846_irq,
1415 irq_flags, spi->dev.driver->name, ts);
1416 }
1417
1418 if (err) {
1419 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1420 goto err_disable_regulator;
1421 }
1422
1423 err = ads784x_hwmon_register(spi, ts);
1424 if (err)
1425 goto err_free_irq;
1426
1427 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1428
1429 /*
1430 * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1431 * the touchscreen, in case it's not connected.
1432 */
1433 if (ts->model == 7845)
1434 ads7845_read12_ser(&spi->dev, PWRDOWN);
1435 else
1436 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1437
1438 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1439 if (err)
1440 goto err_remove_hwmon;
1441
1442 err = input_register_device(input_dev);
1443 if (err)
1444 goto err_remove_attr_group;
1445
1446 device_init_wakeup(&spi->dev, pdata->wakeup);
1447
1448 /*
1449 * If device does not carry platform data we must have allocated it
1450 * when parsing DT data.
1451 */
1452 if (!dev_get_platdata(&spi->dev))
1453 devm_kfree(&spi->dev, (void *)pdata);
1454
1455 return 0;
1456
1457 err_remove_attr_group:
1458 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1459 err_remove_hwmon:
1460 ads784x_hwmon_unregister(spi, ts);
1461 err_free_irq:
1462 free_irq(spi->irq, ts);
1463 err_disable_regulator:
1464 regulator_disable(ts->reg);
1465 err_put_regulator:
1466 regulator_put(ts->reg);
1467 err_free_gpio:
1468 if (!ts->get_pendown_state)
1469 gpio_free(ts->gpio_pendown);
1470 err_cleanup_filter:
1471 if (ts->filter_cleanup)
1472 ts->filter_cleanup(ts->filter_data);
1473 err_free_mem:
1474 input_free_device(input_dev);
1475 kfree(packet);
1476 kfree(ts);
1477 return err;
1478 }
1479
ads7846_remove(struct spi_device * spi)1480 static int ads7846_remove(struct spi_device *spi)
1481 {
1482 struct ads7846 *ts = spi_get_drvdata(spi);
1483
1484 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1485
1486 ads7846_disable(ts);
1487 free_irq(ts->spi->irq, ts);
1488
1489 input_unregister_device(ts->input);
1490
1491 ads784x_hwmon_unregister(spi, ts);
1492
1493 regulator_put(ts->reg);
1494
1495 if (!ts->get_pendown_state) {
1496 /*
1497 * If we are not using specialized pendown method we must
1498 * have been relying on gpio we set up ourselves.
1499 */
1500 gpio_free(ts->gpio_pendown);
1501 }
1502
1503 if (ts->filter_cleanup)
1504 ts->filter_cleanup(ts->filter_data);
1505
1506 kfree(ts->packet);
1507 kfree(ts);
1508
1509 dev_dbg(&spi->dev, "unregistered touchscreen\n");
1510
1511 return 0;
1512 }
1513
1514 static struct spi_driver ads7846_driver = {
1515 .driver = {
1516 .name = "ads7846",
1517 .pm = &ads7846_pm,
1518 .of_match_table = of_match_ptr(ads7846_dt_ids),
1519 },
1520 .probe = ads7846_probe,
1521 .remove = ads7846_remove,
1522 };
1523
1524 module_spi_driver(ads7846_driver);
1525
1526 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1527 MODULE_LICENSE("GPL");
1528 MODULE_ALIAS("spi:ads7846");
1529
