Linux 5.3-rc4
[sfrench/cifs-2.6.git] / drivers / input / touchscreen / ads7846.c
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/interrupt.h>
24 #include <linux/slab.h>
25 #include <linux/pm.h>
26 #include <linux/of.h>
27 #include <linux/of_gpio.h>
28 #include <linux/of_device.h>
29 #include <linux/gpio.h>
30 #include <linux/spi/spi.h>
31 #include <linux/spi/ads7846.h>
32 #include <linux/regulator/consumer.h>
33 #include <linux/module.h>
34 #include <asm/irq.h>
35
36 /*
37  * This code has been heavily tested on a Nokia 770, and lightly
38  * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz).
39  * TSC2046 is just newer ads7846 silicon.
40  * Support for ads7843 tested on Atmel at91sam926x-EK.
41  * Support for ads7845 has only been stubbed in.
42  * Support for Analog Devices AD7873 and AD7843 tested.
43  *
44  * IRQ handling needs a workaround because of a shortcoming in handling
45  * edge triggered IRQs on some platforms like the OMAP1/2. These
46  * platforms don't handle the ARM lazy IRQ disabling properly, thus we
47  * have to maintain our own SW IRQ disabled status. This should be
48  * removed as soon as the affected platform's IRQ handling is fixed.
49  *
50  * App note sbaa036 talks in more detail about accurate sampling...
51  * that ought to help in situations like LCDs inducing noise (which
52  * can also be helped by using synch signals) and more generally.
53  * This driver tries to utilize the measures described in the app
54  * note. The strength of filtering can be set in the board-* specific
55  * files.
56  */
57
58 #define TS_POLL_DELAY   1       /* ms delay before the first sample */
59 #define TS_POLL_PERIOD  5       /* ms delay between samples */
60
61 /* this driver doesn't aim at the peak continuous sample rate */
62 #define SAMPLE_BITS     (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
63
64 struct ts_event {
65         /*
66          * For portability, we can't read 12 bit values using SPI (which
67          * would make the controller deliver them as native byte order u16
68          * with msbs zeroed).  Instead, we read them as two 8-bit values,
69          * *** WHICH NEED BYTESWAPPING *** and range adjustment.
70          */
71         u16     x;
72         u16     y;
73         u16     z1, z2;
74         bool    ignore;
75         u8      x_buf[3];
76         u8      y_buf[3];
77 };
78
79 /*
80  * We allocate this separately to avoid cache line sharing issues when
81  * driver is used with DMA-based SPI controllers (like atmel_spi) on
82  * systems where main memory is not DMA-coherent (most non-x86 boards).
83  */
84 struct ads7846_packet {
85         u8                      read_x, read_y, read_z1, read_z2, pwrdown;
86         u16                     dummy;          /* for the pwrdown read */
87         struct ts_event         tc;
88         /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */
89         u8                      read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
90 };
91
92 struct ads7846 {
93         struct input_dev        *input;
94         char                    phys[32];
95         char                    name[32];
96
97         struct spi_device       *spi;
98         struct regulator        *reg;
99
100 #if IS_ENABLED(CONFIG_HWMON)
101         struct device           *hwmon;
102 #endif
103
104         u16                     model;
105         u16                     vref_mv;
106         u16                     vref_delay_usecs;
107         u16                     x_plate_ohms;
108         u16                     pressure_max;
109
110         bool                    swap_xy;
111         bool                    use_internal;
112
113         struct ads7846_packet   *packet;
114
115         struct spi_transfer     xfer[18];
116         struct spi_message      msg[5];
117         int                     msg_count;
118         wait_queue_head_t       wait;
119
120         bool                    pendown;
121
122         int                     read_cnt;
123         int                     read_rep;
124         int                     last_read;
125
126         u16                     debounce_max;
127         u16                     debounce_tol;
128         u16                     debounce_rep;
129
130         u16                     penirq_recheck_delay_usecs;
131
132         struct mutex            lock;
133         bool                    stopped;        /* P: lock */
134         bool                    disabled;       /* P: lock */
135         bool                    suspended;      /* P: lock */
136
137         int                     (*filter)(void *data, int data_idx, int *val);
138         void                    *filter_data;
139         void                    (*filter_cleanup)(void *data);
140         int                     (*get_pendown_state)(void);
141         int                     gpio_pendown;
142
143         void                    (*wait_for_sync)(void);
144 };
145
146 /* leave chip selected when we're done, for quicker re-select? */
147 #if     0
148 #define CS_CHANGE(xfer) ((xfer).cs_change = 1)
149 #else
150 #define CS_CHANGE(xfer) ((xfer).cs_change = 0)
151 #endif
152
153 /*--------------------------------------------------------------------------*/
154
155 /* The ADS7846 has touchscreen and other sensors.
156  * Earlier ads784x chips are somewhat compatible.
157  */
158 #define ADS_START               (1 << 7)
159 #define ADS_A2A1A0_d_y          (1 << 4)        /* differential */
160 #define ADS_A2A1A0_d_z1         (3 << 4)        /* differential */
161 #define ADS_A2A1A0_d_z2         (4 << 4)        /* differential */
162 #define ADS_A2A1A0_d_x          (5 << 4)        /* differential */
163 #define ADS_A2A1A0_temp0        (0 << 4)        /* non-differential */
164 #define ADS_A2A1A0_vbatt        (2 << 4)        /* non-differential */
165 #define ADS_A2A1A0_vaux         (6 << 4)        /* non-differential */
166 #define ADS_A2A1A0_temp1        (7 << 4)        /* non-differential */
167 #define ADS_8_BIT               (1 << 3)
168 #define ADS_12_BIT              (0 << 3)
169 #define ADS_SER                 (1 << 2)        /* non-differential */
170 #define ADS_DFR                 (0 << 2)        /* differential */
171 #define ADS_PD10_PDOWN          (0 << 0)        /* low power mode + penirq */
172 #define ADS_PD10_ADC_ON         (1 << 0)        /* ADC on */
173 #define ADS_PD10_REF_ON         (2 << 0)        /* vREF on + penirq */
174 #define ADS_PD10_ALL_ON         (3 << 0)        /* ADC + vREF on */
175
176 #define MAX_12BIT       ((1<<12)-1)
177
178 /* leave ADC powered up (disables penirq) between differential samples */
179 #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
180         | ADS_12_BIT | ADS_DFR | \
181         (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
182
183 #define READ_Y(vref)    (READ_12BIT_DFR(y,  1, vref))
184 #define READ_Z1(vref)   (READ_12BIT_DFR(z1, 1, vref))
185 #define READ_Z2(vref)   (READ_12BIT_DFR(z2, 1, vref))
186
187 #define READ_X(vref)    (READ_12BIT_DFR(x,  1, vref))
188 #define PWRDOWN         (READ_12BIT_DFR(y,  0, 0))      /* LAST */
189
190 /* single-ended samples need to first power up reference voltage;
191  * we leave both ADC and VREF powered
192  */
193 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
194         | ADS_12_BIT | ADS_SER)
195
196 #define REF_ON  (READ_12BIT_DFR(x, 1, 1))
197 #define REF_OFF (READ_12BIT_DFR(y, 0, 0))
198
199 /* Must be called with ts->lock held */
200 static void ads7846_stop(struct ads7846 *ts)
201 {
202         if (!ts->disabled && !ts->suspended) {
203                 /* Signal IRQ thread to stop polling and disable the handler. */
204                 ts->stopped = true;
205                 mb();
206                 wake_up(&ts->wait);
207                 disable_irq(ts->spi->irq);
208         }
209 }
210
211 /* Must be called with ts->lock held */
212 static void ads7846_restart(struct ads7846 *ts)
213 {
214         if (!ts->disabled && !ts->suspended) {
215                 /* Tell IRQ thread that it may poll the device. */
216                 ts->stopped = false;
217                 mb();
218                 enable_irq(ts->spi->irq);
219         }
220 }
221
222 /* Must be called with ts->lock held */
223 static void __ads7846_disable(struct ads7846 *ts)
224 {
225         ads7846_stop(ts);
226         regulator_disable(ts->reg);
227
228         /*
229          * We know the chip's in low power mode since we always
230          * leave it that way after every request
231          */
232 }
233
234 /* Must be called with ts->lock held */
235 static void __ads7846_enable(struct ads7846 *ts)
236 {
237         int error;
238
239         error = regulator_enable(ts->reg);
240         if (error != 0)
241                 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error);
242
243         ads7846_restart(ts);
244 }
245
246 static void ads7846_disable(struct ads7846 *ts)
247 {
248         mutex_lock(&ts->lock);
249
250         if (!ts->disabled) {
251
252                 if  (!ts->suspended)
253                         __ads7846_disable(ts);
254
255                 ts->disabled = true;
256         }
257
258         mutex_unlock(&ts->lock);
259 }
260
261 static void ads7846_enable(struct ads7846 *ts)
262 {
263         mutex_lock(&ts->lock);
264
265         if (ts->disabled) {
266
267                 ts->disabled = false;
268
269                 if (!ts->suspended)
270                         __ads7846_enable(ts);
271         }
272
273         mutex_unlock(&ts->lock);
274 }
275
276 /*--------------------------------------------------------------------------*/
277
278 /*
279  * Non-touchscreen sensors only use single-ended conversions.
280  * The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
281  * ads7846 lets that pin be unconnected, to use internal vREF.
282  */
283
284 struct ser_req {
285         u8                      ref_on;
286         u8                      command;
287         u8                      ref_off;
288         u16                     scratch;
289         struct spi_message      msg;
290         struct spi_transfer     xfer[6];
291         /*
292          * DMA (thus cache coherency maintenance) requires the
293          * transfer buffers to live in their own cache lines.
294          */
295         __be16 sample ____cacheline_aligned;
296 };
297
298 struct ads7845_ser_req {
299         u8                      command[3];
300         struct spi_message      msg;
301         struct spi_transfer     xfer[2];
302         /*
303          * DMA (thus cache coherency maintenance) requires the
304          * transfer buffers to live in their own cache lines.
305          */
306         u8 sample[3] ____cacheline_aligned;
307 };
308
309 static int ads7846_read12_ser(struct device *dev, unsigned command)
310 {
311         struct spi_device *spi = to_spi_device(dev);
312         struct ads7846 *ts = dev_get_drvdata(dev);
313         struct ser_req *req;
314         int status;
315
316         req = kzalloc(sizeof *req, GFP_KERNEL);
317         if (!req)
318                 return -ENOMEM;
319
320         spi_message_init(&req->msg);
321
322         /* maybe turn on internal vREF, and let it settle */
323         if (ts->use_internal) {
324                 req->ref_on = REF_ON;
325                 req->xfer[0].tx_buf = &req->ref_on;
326                 req->xfer[0].len = 1;
327                 spi_message_add_tail(&req->xfer[0], &req->msg);
328
329                 req->xfer[1].rx_buf = &req->scratch;
330                 req->xfer[1].len = 2;
331
332                 /* for 1uF, settle for 800 usec; no cap, 100 usec.  */
333                 req->xfer[1].delay_usecs = ts->vref_delay_usecs;
334                 spi_message_add_tail(&req->xfer[1], &req->msg);
335
336                 /* Enable reference voltage */
337                 command |= ADS_PD10_REF_ON;
338         }
339
340         /* Enable ADC in every case */
341         command |= ADS_PD10_ADC_ON;
342
343         /* take sample */
344         req->command = (u8) command;
345         req->xfer[2].tx_buf = &req->command;
346         req->xfer[2].len = 1;
347         spi_message_add_tail(&req->xfer[2], &req->msg);
348
349         req->xfer[3].rx_buf = &req->sample;
350         req->xfer[3].len = 2;
351         spi_message_add_tail(&req->xfer[3], &req->msg);
352
353         /* REVISIT:  take a few more samples, and compare ... */
354
355         /* converter in low power mode & enable PENIRQ */
356         req->ref_off = PWRDOWN;
357         req->xfer[4].tx_buf = &req->ref_off;
358         req->xfer[4].len = 1;
359         spi_message_add_tail(&req->xfer[4], &req->msg);
360
361         req->xfer[5].rx_buf = &req->scratch;
362         req->xfer[5].len = 2;
363         CS_CHANGE(req->xfer[5]);
364         spi_message_add_tail(&req->xfer[5], &req->msg);
365
366         mutex_lock(&ts->lock);
367         ads7846_stop(ts);
368         status = spi_sync(spi, &req->msg);
369         ads7846_restart(ts);
370         mutex_unlock(&ts->lock);
371
372         if (status == 0) {
373                 /* on-wire is a must-ignore bit, a BE12 value, then padding */
374                 status = be16_to_cpu(req->sample);
375                 status = status >> 3;
376                 status &= 0x0fff;
377         }
378
379         kfree(req);
380         return status;
381 }
382
383 static int ads7845_read12_ser(struct device *dev, unsigned command)
384 {
385         struct spi_device *spi = to_spi_device(dev);
386         struct ads7846 *ts = dev_get_drvdata(dev);
387         struct ads7845_ser_req *req;
388         int status;
389
390         req = kzalloc(sizeof *req, GFP_KERNEL);
391         if (!req)
392                 return -ENOMEM;
393
394         spi_message_init(&req->msg);
395
396         req->command[0] = (u8) command;
397         req->xfer[0].tx_buf = req->command;
398         req->xfer[0].rx_buf = req->sample;
399         req->xfer[0].len = 3;
400         spi_message_add_tail(&req->xfer[0], &req->msg);
401
402         mutex_lock(&ts->lock);
403         ads7846_stop(ts);
404         status = spi_sync(spi, &req->msg);
405         ads7846_restart(ts);
406         mutex_unlock(&ts->lock);
407
408         if (status == 0) {
409                 /* BE12 value, then padding */
410                 status = be16_to_cpu(*((u16 *)&req->sample[1]));
411                 status = status >> 3;
412                 status &= 0x0fff;
413         }
414
415         kfree(req);
416         return status;
417 }
418
419 #if IS_ENABLED(CONFIG_HWMON)
420
421 #define SHOW(name, var, adjust) static ssize_t \
422 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
423 { \
424         struct ads7846 *ts = dev_get_drvdata(dev); \
425         ssize_t v = ads7846_read12_ser(&ts->spi->dev, \
426                         READ_12BIT_SER(var)); \
427         if (v < 0) \
428                 return v; \
429         return sprintf(buf, "%u\n", adjust(ts, v)); \
430 } \
431 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
432
433
434 /* Sysfs conventions report temperatures in millidegrees Celsius.
435  * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
436  * accuracy scheme without calibration data.  For now we won't try either;
437  * userspace sees raw sensor values, and must scale/calibrate appropriately.
438  */
439 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
440 {
441         return v;
442 }
443
444 SHOW(temp0, temp0, null_adjust)         /* temp1_input */
445 SHOW(temp1, temp1, null_adjust)         /* temp2_input */
446
447
448 /* sysfs conventions report voltages in millivolts.  We can convert voltages
449  * if we know vREF.  userspace may need to scale vAUX to match the board's
450  * external resistors; we assume that vBATT only uses the internal ones.
451  */
452 static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
453 {
454         unsigned retval = v;
455
456         /* external resistors may scale vAUX into 0..vREF */
457         retval *= ts->vref_mv;
458         retval = retval >> 12;
459
460         return retval;
461 }
462
463 static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
464 {
465         unsigned retval = vaux_adjust(ts, v);
466
467         /* ads7846 has a resistor ladder to scale this signal down */
468         if (ts->model == 7846)
469                 retval *= 4;
470
471         return retval;
472 }
473
474 SHOW(in0_input, vaux, vaux_adjust)
475 SHOW(in1_input, vbatt, vbatt_adjust)
476
477 static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr,
478                                   int index)
479 {
480         struct device *dev = container_of(kobj, struct device, kobj);
481         struct ads7846 *ts = dev_get_drvdata(dev);
482
483         if (ts->model == 7843 && index < 2)     /* in0, in1 */
484                 return 0;
485         if (ts->model == 7845 && index != 2)    /* in0 */
486                 return 0;
487
488         return attr->mode;
489 }
490
491 static struct attribute *ads7846_attributes[] = {
492         &dev_attr_temp0.attr,           /* 0 */
493         &dev_attr_temp1.attr,           /* 1 */
494         &dev_attr_in0_input.attr,       /* 2 */
495         &dev_attr_in1_input.attr,       /* 3 */
496         NULL,
497 };
498
499 static const struct attribute_group ads7846_attr_group = {
500         .attrs = ads7846_attributes,
501         .is_visible = ads7846_is_visible,
502 };
503 __ATTRIBUTE_GROUPS(ads7846_attr);
504
505 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
506 {
507         /* hwmon sensors need a reference voltage */
508         switch (ts->model) {
509         case 7846:
510                 if (!ts->vref_mv) {
511                         dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
512                         ts->vref_mv = 2500;
513                         ts->use_internal = true;
514                 }
515                 break;
516         case 7845:
517         case 7843:
518                 if (!ts->vref_mv) {
519                         dev_warn(&spi->dev,
520                                 "external vREF for ADS%d not specified\n",
521                                 ts->model);
522                         return 0;
523                 }
524                 break;
525         }
526
527         ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias,
528                                                       ts, ads7846_attr_groups);
529
530         return PTR_ERR_OR_ZERO(ts->hwmon);
531 }
532
533 static void ads784x_hwmon_unregister(struct spi_device *spi,
534                                      struct ads7846 *ts)
535 {
536         if (ts->hwmon)
537                 hwmon_device_unregister(ts->hwmon);
538 }
539
540 #else
541 static inline int ads784x_hwmon_register(struct spi_device *spi,
542                                          struct ads7846 *ts)
543 {
544         return 0;
545 }
546
547 static inline void ads784x_hwmon_unregister(struct spi_device *spi,
548                                             struct ads7846 *ts)
549 {
550 }
551 #endif
552
553 static ssize_t ads7846_pen_down_show(struct device *dev,
554                                      struct device_attribute *attr, char *buf)
555 {
556         struct ads7846 *ts = dev_get_drvdata(dev);
557
558         return sprintf(buf, "%u\n", ts->pendown);
559 }
560
561 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
562
563 static ssize_t ads7846_disable_show(struct device *dev,
564                                      struct device_attribute *attr, char *buf)
565 {
566         struct ads7846 *ts = dev_get_drvdata(dev);
567
568         return sprintf(buf, "%u\n", ts->disabled);
569 }
570
571 static ssize_t ads7846_disable_store(struct device *dev,
572                                      struct device_attribute *attr,
573                                      const char *buf, size_t count)
574 {
575         struct ads7846 *ts = dev_get_drvdata(dev);
576         unsigned int i;
577         int err;
578
579         err = kstrtouint(buf, 10, &i);
580         if (err)
581                 return err;
582
583         if (i)
584                 ads7846_disable(ts);
585         else
586                 ads7846_enable(ts);
587
588         return count;
589 }
590
591 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
592
593 static struct attribute *ads784x_attributes[] = {
594         &dev_attr_pen_down.attr,
595         &dev_attr_disable.attr,
596         NULL,
597 };
598
599 static const struct attribute_group ads784x_attr_group = {
600         .attrs = ads784x_attributes,
601 };
602
603 /*--------------------------------------------------------------------------*/
604
605 static int get_pendown_state(struct ads7846 *ts)
606 {
607         if (ts->get_pendown_state)
608                 return ts->get_pendown_state();
609
610         return !gpio_get_value(ts->gpio_pendown);
611 }
612
613 static void null_wait_for_sync(void)
614 {
615 }
616
617 static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
618 {
619         struct ads7846 *ts = ads;
620
621         if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
622                 /* Start over collecting consistent readings. */
623                 ts->read_rep = 0;
624                 /*
625                  * Repeat it, if this was the first read or the read
626                  * wasn't consistent enough.
627                  */
628                 if (ts->read_cnt < ts->debounce_max) {
629                         ts->last_read = *val;
630                         ts->read_cnt++;
631                         return ADS7846_FILTER_REPEAT;
632                 } else {
633                         /*
634                          * Maximum number of debouncing reached and still
635                          * not enough number of consistent readings. Abort
636                          * the whole sample, repeat it in the next sampling
637                          * period.
638                          */
639                         ts->read_cnt = 0;
640                         return ADS7846_FILTER_IGNORE;
641                 }
642         } else {
643                 if (++ts->read_rep > ts->debounce_rep) {
644                         /*
645                          * Got a good reading for this coordinate,
646                          * go for the next one.
647                          */
648                         ts->read_cnt = 0;
649                         ts->read_rep = 0;
650                         return ADS7846_FILTER_OK;
651                 } else {
652                         /* Read more values that are consistent. */
653                         ts->read_cnt++;
654                         return ADS7846_FILTER_REPEAT;
655                 }
656         }
657 }
658
659 static int ads7846_no_filter(void *ads, int data_idx, int *val)
660 {
661         return ADS7846_FILTER_OK;
662 }
663
664 static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
665 {
666         int value;
667         struct spi_transfer *t =
668                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
669
670         if (ts->model == 7845) {
671                 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1]));
672         } else {
673                 /*
674                  * adjust:  on-wire is a must-ignore bit, a BE12 value, then
675                  * padding; built from two 8 bit values written msb-first.
676                  */
677                 value = be16_to_cpup((__be16 *)t->rx_buf);
678         }
679
680         /* enforce ADC output is 12 bits width */
681         return (value >> 3) & 0xfff;
682 }
683
684 static void ads7846_update_value(struct spi_message *m, int val)
685 {
686         struct spi_transfer *t =
687                 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
688
689         *(u16 *)t->rx_buf = val;
690 }
691
692 static void ads7846_read_state(struct ads7846 *ts)
693 {
694         struct ads7846_packet *packet = ts->packet;
695         struct spi_message *m;
696         int msg_idx = 0;
697         int val;
698         int action;
699         int error;
700
701         while (msg_idx < ts->msg_count) {
702
703                 ts->wait_for_sync();
704
705                 m = &ts->msg[msg_idx];
706                 error = spi_sync(ts->spi, m);
707                 if (error) {
708                         dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
709                         packet->tc.ignore = true;
710                         return;
711                 }
712
713                 /*
714                  * Last message is power down request, no need to convert
715                  * or filter the value.
716                  */
717                 if (msg_idx < ts->msg_count - 1) {
718
719                         val = ads7846_get_value(ts, m);
720
721                         action = ts->filter(ts->filter_data, msg_idx, &val);
722                         switch (action) {
723                         case ADS7846_FILTER_REPEAT:
724                                 continue;
725
726                         case ADS7846_FILTER_IGNORE:
727                                 packet->tc.ignore = true;
728                                 msg_idx = ts->msg_count - 1;
729                                 continue;
730
731                         case ADS7846_FILTER_OK:
732                                 ads7846_update_value(m, val);
733                                 packet->tc.ignore = false;
734                                 msg_idx++;
735                                 break;
736
737                         default:
738                                 BUG();
739                         }
740                 } else {
741                         msg_idx++;
742                 }
743         }
744 }
745
746 static void ads7846_report_state(struct ads7846 *ts)
747 {
748         struct ads7846_packet *packet = ts->packet;
749         unsigned int Rt;
750         u16 x, y, z1, z2;
751
752         /*
753          * ads7846_get_value() does in-place conversion (including byte swap)
754          * from on-the-wire format as part of debouncing to get stable
755          * readings.
756          */
757         if (ts->model == 7845) {
758                 x = *(u16 *)packet->tc.x_buf;
759                 y = *(u16 *)packet->tc.y_buf;
760                 z1 = 0;
761                 z2 = 0;
762         } else {
763                 x = packet->tc.x;
764                 y = packet->tc.y;
765                 z1 = packet->tc.z1;
766                 z2 = packet->tc.z2;
767         }
768
769         /* range filtering */
770         if (x == MAX_12BIT)
771                 x = 0;
772
773         if (ts->model == 7843) {
774                 Rt = ts->pressure_max / 2;
775         } else if (ts->model == 7845) {
776                 if (get_pendown_state(ts))
777                         Rt = ts->pressure_max / 2;
778                 else
779                         Rt = 0;
780                 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
781         } else if (likely(x && z1)) {
782                 /* compute touch pressure resistance using equation #2 */
783                 Rt = z2;
784                 Rt -= z1;
785                 Rt *= x;
786                 Rt *= ts->x_plate_ohms;
787                 Rt /= z1;
788                 Rt = (Rt + 2047) >> 12;
789         } else {
790                 Rt = 0;
791         }
792
793         /*
794          * Sample found inconsistent by debouncing or pressure is beyond
795          * the maximum. Don't report it to user space, repeat at least
796          * once more the measurement
797          */
798         if (packet->tc.ignore || Rt > ts->pressure_max) {
799                 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
800                          packet->tc.ignore, Rt);
801                 return;
802         }
803
804         /*
805          * Maybe check the pendown state before reporting. This discards
806          * false readings when the pen is lifted.
807          */
808         if (ts->penirq_recheck_delay_usecs) {
809                 udelay(ts->penirq_recheck_delay_usecs);
810                 if (!get_pendown_state(ts))
811                         Rt = 0;
812         }
813
814         /*
815          * NOTE: We can't rely on the pressure to determine the pen down
816          * state, even this controller has a pressure sensor. The pressure
817          * value can fluctuate for quite a while after lifting the pen and
818          * in some cases may not even settle at the expected value.
819          *
820          * The only safe way to check for the pen up condition is in the
821          * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
822          */
823         if (Rt) {
824                 struct input_dev *input = ts->input;
825
826                 if (ts->swap_xy)
827                         swap(x, y);
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                 input_report_abs(input, ABS_X, x);
836                 input_report_abs(input, ABS_Y, y);
837                 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
838
839                 input_sync(input);
840                 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
841         }
842 }
843
844 static irqreturn_t ads7846_hard_irq(int irq, void *handle)
845 {
846         struct ads7846 *ts = handle;
847
848         return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
849 }
850
851
852 static irqreturn_t ads7846_irq(int irq, void *handle)
853 {
854         struct ads7846 *ts = handle;
855
856         /* Start with a small delay before checking pendown state */
857         msleep(TS_POLL_DELAY);
858
859         while (!ts->stopped && get_pendown_state(ts)) {
860
861                 /* pen is down, continue with the measurement */
862                 ads7846_read_state(ts);
863
864                 if (!ts->stopped)
865                         ads7846_report_state(ts);
866
867                 wait_event_timeout(ts->wait, ts->stopped,
868                                    msecs_to_jiffies(TS_POLL_PERIOD));
869         }
870
871         if (ts->pendown && !ts->stopped) {
872                 struct input_dev *input = ts->input;
873
874                 input_report_key(input, BTN_TOUCH, 0);
875                 input_report_abs(input, ABS_PRESSURE, 0);
876                 input_sync(input);
877
878                 ts->pendown = false;
879                 dev_vdbg(&ts->spi->dev, "UP\n");
880         }
881
882         return IRQ_HANDLED;
883 }
884
885 static int __maybe_unused ads7846_suspend(struct device *dev)
886 {
887         struct ads7846 *ts = dev_get_drvdata(dev);
888
889         mutex_lock(&ts->lock);
890
891         if (!ts->suspended) {
892
893                 if (!ts->disabled)
894                         __ads7846_disable(ts);
895
896                 if (device_may_wakeup(&ts->spi->dev))
897                         enable_irq_wake(ts->spi->irq);
898
899                 ts->suspended = true;
900         }
901
902         mutex_unlock(&ts->lock);
903
904         return 0;
905 }
906
907 static int __maybe_unused ads7846_resume(struct device *dev)
908 {
909         struct ads7846 *ts = dev_get_drvdata(dev);
910
911         mutex_lock(&ts->lock);
912
913         if (ts->suspended) {
914
915                 ts->suspended = false;
916
917                 if (device_may_wakeup(&ts->spi->dev))
918                         disable_irq_wake(ts->spi->irq);
919
920                 if (!ts->disabled)
921                         __ads7846_enable(ts);
922         }
923
924         mutex_unlock(&ts->lock);
925
926         return 0;
927 }
928
929 static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
930
931 static int ads7846_setup_pendown(struct spi_device *spi,
932                                  struct ads7846 *ts,
933                                  const struct ads7846_platform_data *pdata)
934 {
935         int err;
936
937         /*
938          * REVISIT when the irq can be triggered active-low, or if for some
939          * reason the touchscreen isn't hooked up, we don't need to access
940          * the pendown state.
941          */
942
943         if (pdata->get_pendown_state) {
944                 ts->get_pendown_state = pdata->get_pendown_state;
945         } else if (gpio_is_valid(pdata->gpio_pendown)) {
946
947                 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
948                                        "ads7846_pendown");
949                 if (err) {
950                         dev_err(&spi->dev,
951                                 "failed to request/setup pendown GPIO%d: %d\n",
952                                 pdata->gpio_pendown, err);
953                         return err;
954                 }
955
956                 ts->gpio_pendown = pdata->gpio_pendown;
957
958                 if (pdata->gpio_pendown_debounce)
959                         gpio_set_debounce(pdata->gpio_pendown,
960                                           pdata->gpio_pendown_debounce);
961         } else {
962                 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
963                 return -EINVAL;
964         }
965
966         return 0;
967 }
968
969 /*
970  * Set up the transfers to read touchscreen state; this assumes we
971  * use formula #2 for pressure, not #3.
972  */
973 static void ads7846_setup_spi_msg(struct ads7846 *ts,
974                                   const struct ads7846_platform_data *pdata)
975 {
976         struct spi_message *m = &ts->msg[0];
977         struct spi_transfer *x = ts->xfer;
978         struct ads7846_packet *packet = ts->packet;
979         int vref = pdata->keep_vref_on;
980
981         if (ts->model == 7873) {
982                 /*
983                  * The AD7873 is almost identical to the ADS7846
984                  * keep VREF off during differential/ratiometric
985                  * conversion modes.
986                  */
987                 ts->model = 7846;
988                 vref = 0;
989         }
990
991         ts->msg_count = 1;
992         spi_message_init(m);
993         m->context = ts;
994
995         if (ts->model == 7845) {
996                 packet->read_y_cmd[0] = READ_Y(vref);
997                 packet->read_y_cmd[1] = 0;
998                 packet->read_y_cmd[2] = 0;
999                 x->tx_buf = &packet->read_y_cmd[0];
1000                 x->rx_buf = &packet->tc.y_buf[0];
1001                 x->len = 3;
1002                 spi_message_add_tail(x, m);
1003         } else {
1004                 /* y- still on; turn on only y+ (and ADC) */
1005                 packet->read_y = READ_Y(vref);
1006                 x->tx_buf = &packet->read_y;
1007                 x->len = 1;
1008                 spi_message_add_tail(x, m);
1009
1010                 x++;
1011                 x->rx_buf = &packet->tc.y;
1012                 x->len = 2;
1013                 spi_message_add_tail(x, m);
1014         }
1015
1016         /*
1017          * The first sample after switching drivers can be low quality;
1018          * optionally discard it, using a second one after the signals
1019          * have had enough time to stabilize.
1020          */
1021         if (pdata->settle_delay_usecs) {
1022                 x->delay_usecs = pdata->settle_delay_usecs;
1023
1024                 x++;
1025                 x->tx_buf = &packet->read_y;
1026                 x->len = 1;
1027                 spi_message_add_tail(x, m);
1028
1029                 x++;
1030                 x->rx_buf = &packet->tc.y;
1031                 x->len = 2;
1032                 spi_message_add_tail(x, m);
1033         }
1034
1035         ts->msg_count++;
1036         m++;
1037         spi_message_init(m);
1038         m->context = ts;
1039
1040         if (ts->model == 7845) {
1041                 x++;
1042                 packet->read_x_cmd[0] = READ_X(vref);
1043                 packet->read_x_cmd[1] = 0;
1044                 packet->read_x_cmd[2] = 0;
1045                 x->tx_buf = &packet->read_x_cmd[0];
1046                 x->rx_buf = &packet->tc.x_buf[0];
1047                 x->len = 3;
1048                 spi_message_add_tail(x, m);
1049         } else {
1050                 /* turn y- off, x+ on, then leave in lowpower */
1051                 x++;
1052                 packet->read_x = READ_X(vref);
1053                 x->tx_buf = &packet->read_x;
1054                 x->len = 1;
1055                 spi_message_add_tail(x, m);
1056
1057                 x++;
1058                 x->rx_buf = &packet->tc.x;
1059                 x->len = 2;
1060                 spi_message_add_tail(x, m);
1061         }
1062
1063         /* ... maybe discard first sample ... */
1064         if (pdata->settle_delay_usecs) {
1065                 x->delay_usecs = pdata->settle_delay_usecs;
1066
1067                 x++;
1068                 x->tx_buf = &packet->read_x;
1069                 x->len = 1;
1070                 spi_message_add_tail(x, m);
1071
1072                 x++;
1073                 x->rx_buf = &packet->tc.x;
1074                 x->len = 2;
1075                 spi_message_add_tail(x, m);
1076         }
1077
1078         /* turn y+ off, x- on; we'll use formula #2 */
1079         if (ts->model == 7846) {
1080                 ts->msg_count++;
1081                 m++;
1082                 spi_message_init(m);
1083                 m->context = ts;
1084
1085                 x++;
1086                 packet->read_z1 = READ_Z1(vref);
1087                 x->tx_buf = &packet->read_z1;
1088                 x->len = 1;
1089                 spi_message_add_tail(x, m);
1090
1091                 x++;
1092                 x->rx_buf = &packet->tc.z1;
1093                 x->len = 2;
1094                 spi_message_add_tail(x, m);
1095
1096                 /* ... maybe discard first sample ... */
1097                 if (pdata->settle_delay_usecs) {
1098                         x->delay_usecs = pdata->settle_delay_usecs;
1099
1100                         x++;
1101                         x->tx_buf = &packet->read_z1;
1102                         x->len = 1;
1103                         spi_message_add_tail(x, m);
1104
1105                         x++;
1106                         x->rx_buf = &packet->tc.z1;
1107                         x->len = 2;
1108                         spi_message_add_tail(x, m);
1109                 }
1110
1111                 ts->msg_count++;
1112                 m++;
1113                 spi_message_init(m);
1114                 m->context = ts;
1115
1116                 x++;
1117                 packet->read_z2 = READ_Z2(vref);
1118                 x->tx_buf = &packet->read_z2;
1119                 x->len = 1;
1120                 spi_message_add_tail(x, m);
1121
1122                 x++;
1123                 x->rx_buf = &packet->tc.z2;
1124                 x->len = 2;
1125                 spi_message_add_tail(x, m);
1126
1127                 /* ... maybe discard first sample ... */
1128                 if (pdata->settle_delay_usecs) {
1129                         x->delay_usecs = pdata->settle_delay_usecs;
1130
1131                         x++;
1132                         x->tx_buf = &packet->read_z2;
1133                         x->len = 1;
1134                         spi_message_add_tail(x, m);
1135
1136                         x++;
1137                         x->rx_buf = &packet->tc.z2;
1138                         x->len = 2;
1139                         spi_message_add_tail(x, m);
1140                 }
1141         }
1142
1143         /* power down */
1144         ts->msg_count++;
1145         m++;
1146         spi_message_init(m);
1147         m->context = ts;
1148
1149         if (ts->model == 7845) {
1150                 x++;
1151                 packet->pwrdown_cmd[0] = PWRDOWN;
1152                 packet->pwrdown_cmd[1] = 0;
1153                 packet->pwrdown_cmd[2] = 0;
1154                 x->tx_buf = &packet->pwrdown_cmd[0];
1155                 x->len = 3;
1156         } else {
1157                 x++;
1158                 packet->pwrdown = PWRDOWN;
1159                 x->tx_buf = &packet->pwrdown;
1160                 x->len = 1;
1161                 spi_message_add_tail(x, m);
1162
1163                 x++;
1164                 x->rx_buf = &packet->dummy;
1165                 x->len = 2;
1166         }
1167
1168         CS_CHANGE(*x);
1169         spi_message_add_tail(x, m);
1170 }
1171
1172 #ifdef CONFIG_OF
1173 static const struct of_device_id ads7846_dt_ids[] = {
1174         { .compatible = "ti,tsc2046",   .data = (void *) 7846 },
1175         { .compatible = "ti,ads7843",   .data = (void *) 7843 },
1176         { .compatible = "ti,ads7845",   .data = (void *) 7845 },
1177         { .compatible = "ti,ads7846",   .data = (void *) 7846 },
1178         { .compatible = "ti,ads7873",   .data = (void *) 7873 },
1179         { }
1180 };
1181 MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1182
1183 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1184 {
1185         struct ads7846_platform_data *pdata;
1186         struct device_node *node = dev->of_node;
1187         const struct of_device_id *match;
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         of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1227         of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1228
1229         of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1230         of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1231         of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1232
1233         of_property_read_u32(node, "ti,pendown-gpio-debounce",
1234                              &pdata->gpio_pendown_debounce);
1235
1236         pdata->wakeup = of_property_read_bool(node, "wakeup-source") ||
1237                         of_property_read_bool(node, "linux,wakeup");
1238
1239         pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1240
1241         return pdata;
1242 }
1243 #else
1244 static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1245 {
1246         dev_err(dev, "no platform data defined\n");
1247         return ERR_PTR(-EINVAL);
1248 }
1249 #endif
1250
1251 static int ads7846_probe(struct spi_device *spi)
1252 {
1253         const struct ads7846_platform_data *pdata;
1254         struct ads7846 *ts;
1255         struct ads7846_packet *packet;
1256         struct input_dev *input_dev;
1257         unsigned long irq_flags;
1258         int err;
1259
1260         if (!spi->irq) {
1261                 dev_dbg(&spi->dev, "no IRQ?\n");
1262                 return -EINVAL;
1263         }
1264
1265         /* don't exceed max specified sample rate */
1266         if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1267                 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1268                                 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1269                 return -EINVAL;
1270         }
1271
1272         /*
1273          * We'd set TX word size 8 bits and RX word size to 13 bits ... except
1274          * that even if the hardware can do that, the SPI controller driver
1275          * may not.  So we stick to very-portable 8 bit words, both RX and TX.
1276          */
1277         spi->bits_per_word = 8;
1278         spi->mode = SPI_MODE_0;
1279         err = spi_setup(spi);
1280         if (err < 0)
1281                 return err;
1282
1283         ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1284         packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1285         input_dev = input_allocate_device();
1286         if (!ts || !packet || !input_dev) {
1287                 err = -ENOMEM;
1288                 goto err_free_mem;
1289         }
1290
1291         spi_set_drvdata(spi, ts);
1292
1293         ts->packet = packet;
1294         ts->spi = spi;
1295         ts->input = input_dev;
1296
1297         mutex_init(&ts->lock);
1298         init_waitqueue_head(&ts->wait);
1299
1300         pdata = dev_get_platdata(&spi->dev);
1301         if (!pdata) {
1302                 pdata = ads7846_probe_dt(&spi->dev);
1303                 if (IS_ERR(pdata)) {
1304                         err = PTR_ERR(pdata);
1305                         goto err_free_mem;
1306                 }
1307         }
1308
1309         ts->model = pdata->model ? : 7846;
1310         ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1311         ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1312         ts->pressure_max = pdata->pressure_max ? : ~0;
1313
1314         ts->vref_mv = pdata->vref_mv;
1315         ts->swap_xy = pdata->swap_xy;
1316
1317         if (pdata->filter != NULL) {
1318                 if (pdata->filter_init != NULL) {
1319                         err = pdata->filter_init(pdata, &ts->filter_data);
1320                         if (err < 0)
1321                                 goto err_free_mem;
1322                 }
1323                 ts->filter = pdata->filter;
1324                 ts->filter_cleanup = pdata->filter_cleanup;
1325         } else if (pdata->debounce_max) {
1326                 ts->debounce_max = pdata->debounce_max;
1327                 if (ts->debounce_max < 2)
1328                         ts->debounce_max = 2;
1329                 ts->debounce_tol = pdata->debounce_tol;
1330                 ts->debounce_rep = pdata->debounce_rep;
1331                 ts->filter = ads7846_debounce_filter;
1332                 ts->filter_data = ts;
1333         } else {
1334                 ts->filter = ads7846_no_filter;
1335         }
1336
1337         err = ads7846_setup_pendown(spi, ts, pdata);
1338         if (err)
1339                 goto err_cleanup_filter;
1340
1341         if (pdata->penirq_recheck_delay_usecs)
1342                 ts->penirq_recheck_delay_usecs =
1343                                 pdata->penirq_recheck_delay_usecs;
1344
1345         ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1346
1347         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1348         snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1349
1350         input_dev->name = ts->name;
1351         input_dev->phys = ts->phys;
1352         input_dev->dev.parent = &spi->dev;
1353
1354         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1355         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1356         input_set_abs_params(input_dev, ABS_X,
1357                         pdata->x_min ? : 0,
1358                         pdata->x_max ? : MAX_12BIT,
1359                         0, 0);
1360         input_set_abs_params(input_dev, ABS_Y,
1361                         pdata->y_min ? : 0,
1362                         pdata->y_max ? : MAX_12BIT,
1363                         0, 0);
1364         input_set_abs_params(input_dev, ABS_PRESSURE,
1365                         pdata->pressure_min, pdata->pressure_max, 0, 0);
1366
1367         ads7846_setup_spi_msg(ts, pdata);
1368
1369         ts->reg = regulator_get(&spi->dev, "vcc");
1370         if (IS_ERR(ts->reg)) {
1371                 err = PTR_ERR(ts->reg);
1372                 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1373                 goto err_free_gpio;
1374         }
1375
1376         err = regulator_enable(ts->reg);
1377         if (err) {
1378                 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1379                 goto err_put_regulator;
1380         }
1381
1382         irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1383         irq_flags |= IRQF_ONESHOT;
1384
1385         err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1386                                    irq_flags, spi->dev.driver->name, ts);
1387         if (err && !pdata->irq_flags) {
1388                 dev_info(&spi->dev,
1389                         "trying pin change workaround on irq %d\n", spi->irq);
1390                 irq_flags |= IRQF_TRIGGER_RISING;
1391                 err = request_threaded_irq(spi->irq,
1392                                   ads7846_hard_irq, ads7846_irq,
1393                                   irq_flags, spi->dev.driver->name, ts);
1394         }
1395
1396         if (err) {
1397                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1398                 goto err_disable_regulator;
1399         }
1400
1401         err = ads784x_hwmon_register(spi, ts);
1402         if (err)
1403                 goto err_free_irq;
1404
1405         dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1406
1407         /*
1408          * Take a first sample, leaving nPENIRQ active and vREF off; avoid
1409          * the touchscreen, in case it's not connected.
1410          */
1411         if (ts->model == 7845)
1412                 ads7845_read12_ser(&spi->dev, PWRDOWN);
1413         else
1414                 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1415
1416         err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1417         if (err)
1418                 goto err_remove_hwmon;
1419
1420         err = input_register_device(input_dev);
1421         if (err)
1422                 goto err_remove_attr_group;
1423
1424         device_init_wakeup(&spi->dev, pdata->wakeup);
1425
1426         /*
1427          * If device does not carry platform data we must have allocated it
1428          * when parsing DT data.
1429          */
1430         if (!dev_get_platdata(&spi->dev))
1431                 devm_kfree(&spi->dev, (void *)pdata);
1432
1433         return 0;
1434
1435  err_remove_attr_group:
1436         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1437  err_remove_hwmon:
1438         ads784x_hwmon_unregister(spi, ts);
1439  err_free_irq:
1440         free_irq(spi->irq, ts);
1441  err_disable_regulator:
1442         regulator_disable(ts->reg);
1443  err_put_regulator:
1444         regulator_put(ts->reg);
1445  err_free_gpio:
1446         if (!ts->get_pendown_state)
1447                 gpio_free(ts->gpio_pendown);
1448  err_cleanup_filter:
1449         if (ts->filter_cleanup)
1450                 ts->filter_cleanup(ts->filter_data);
1451  err_free_mem:
1452         input_free_device(input_dev);
1453         kfree(packet);
1454         kfree(ts);
1455         return err;
1456 }
1457
1458 static int ads7846_remove(struct spi_device *spi)
1459 {
1460         struct ads7846 *ts = spi_get_drvdata(spi);
1461
1462         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1463
1464         ads7846_disable(ts);
1465         free_irq(ts->spi->irq, ts);
1466
1467         input_unregister_device(ts->input);
1468
1469         ads784x_hwmon_unregister(spi, ts);
1470
1471         regulator_put(ts->reg);
1472
1473         if (!ts->get_pendown_state) {
1474                 /*
1475                  * If we are not using specialized pendown method we must
1476                  * have been relying on gpio we set up ourselves.
1477                  */
1478                 gpio_free(ts->gpio_pendown);
1479         }
1480
1481         if (ts->filter_cleanup)
1482                 ts->filter_cleanup(ts->filter_data);
1483
1484         kfree(ts->packet);
1485         kfree(ts);
1486
1487         dev_dbg(&spi->dev, "unregistered touchscreen\n");
1488
1489         return 0;
1490 }
1491
1492 static struct spi_driver ads7846_driver = {
1493         .driver = {
1494                 .name   = "ads7846",
1495                 .pm     = &ads7846_pm,
1496                 .of_match_table = of_match_ptr(ads7846_dt_ids),
1497         },
1498         .probe          = ads7846_probe,
1499         .remove         = ads7846_remove,
1500 };
1501
1502 module_spi_driver(ads7846_driver);
1503
1504 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1505 MODULE_LICENSE("GPL");
1506 MODULE_ALIAS("spi:ads7846");