Merge tag 'v5.3-rc4' into next
[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/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 */
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 */
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 */
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 */
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
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
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
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
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  */
442 static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
443 {
444         return v;
445 }
446
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
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
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
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
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
544 static inline int ads784x_hwmon_register(struct spi_device *spi,
545                                          struct ads7846 *ts)
546 {
547         return 0;
548 }
549
550 static inline void ads784x_hwmon_unregister(struct spi_device *spi,
551                                             struct ads7846 *ts)
552 {
553 }
554 #endif
555
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
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
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
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
616 static void null_wait_for_sync(void)
617 {
618 }
619
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
662 static int ads7846_no_filter(void *ads, int data_idx, int *val)
663 {
664         return ADS7846_FILTER_OK;
665 }
666
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
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
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
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
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
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
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
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
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  */
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
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
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
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
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");