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20#include <linux/types.h>
21#include <linux/hwmon.h>
22#include <linux/err.h>
23#include <linux/sched.h>
24#include <linux/delay.h>
25#include <linux/input.h>
26#include <linux/interrupt.h>
27#include <linux/slab.h>
28#include <linux/pm.h>
29#include <linux/of.h>
30#include <linux/of_gpio.h>
31#include <linux/of_device.h>
32#include <linux/gpio.h>
33#include <linux/spi/spi.h>
34#include <linux/spi/ads7846.h>
35#include <linux/regulator/consumer.h>
36#include <linux/module.h>
37#include <asm/irq.h>
38
39
40
41
42
43
44
45
46
47
48
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51
52
53
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55
56
57
58
59
60
61#define TS_POLL_DELAY 1
62#define TS_POLL_PERIOD 5
63
64
65#define SAMPLE_BITS (8 + 16 + 2 )
66
67struct ts_event {
68
69
70
71
72
73
74 u16 x;
75 u16 y;
76 u16 z1, z2;
77 bool ignore;
78 u8 x_buf[3];
79 u8 y_buf[3];
80};
81
82
83
84
85
86
87struct ads7846_packet {
88 u8 read_x, read_y, read_z1, read_z2, pwrdown;
89 u16 dummy;
90 struct ts_event tc;
91
92 u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3];
93};
94
95struct ads7846 {
96 struct input_dev *input;
97 char phys[32];
98 char name[32];
99
100 struct spi_device *spi;
101 struct regulator *reg;
102
103#if IS_ENABLED(CONFIG_HWMON)
104 struct device *hwmon;
105#endif
106
107 u16 model;
108 u16 vref_mv;
109 u16 vref_delay_usecs;
110 u16 x_plate_ohms;
111 u16 pressure_max;
112
113 bool swap_xy;
114 bool use_internal;
115
116 struct ads7846_packet *packet;
117
118 struct spi_transfer xfer[18];
119 struct spi_message msg[5];
120 int msg_count;
121 wait_queue_head_t wait;
122
123 bool pendown;
124
125 int read_cnt;
126 int read_rep;
127 int last_read;
128
129 u16 debounce_max;
130 u16 debounce_tol;
131 u16 debounce_rep;
132
133 u16 penirq_recheck_delay_usecs;
134
135 struct mutex lock;
136 bool stopped;
137 bool disabled;
138 bool suspended;
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
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
159
160
161#define ADS_START (1 << 7)
162#define ADS_A2A1A0_d_y (1 << 4)
163#define ADS_A2A1A0_d_z1 (3 << 4)
164#define ADS_A2A1A0_d_z2 (4 << 4)
165#define ADS_A2A1A0_d_x (5 << 4)
166#define ADS_A2A1A0_temp0 (0 << 4)
167#define ADS_A2A1A0_vbatt (2 << 4)
168#define ADS_A2A1A0_vaux (6 << 4)
169#define ADS_A2A1A0_temp1 (7 << 4)
170#define ADS_8_BIT (1 << 3)
171#define ADS_12_BIT (0 << 3)
172#define ADS_SER (1 << 2)
173#define ADS_DFR (0 << 2)
174#define ADS_PD10_PDOWN (0 << 0)
175#define ADS_PD10_ADC_ON (1 << 0)
176#define ADS_PD10_REF_ON (2 << 0)
177#define ADS_PD10_ALL_ON (3 << 0)
178
179#define MAX_12BIT ((1<<12)-1)
180
181
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))
192
193
194
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
203static void ads7846_stop(struct ads7846 *ts)
204{
205 if (!ts->disabled && !ts->suspended) {
206
207 ts->stopped = true;
208 mb();
209 wake_up(&ts->wait);
210 disable_irq(ts->spi->irq);
211 }
212}
213
214
215static void ads7846_restart(struct ads7846 *ts)
216{
217 if (!ts->disabled && !ts->suspended) {
218
219 ts->stopped = false;
220 mb();
221 enable_irq(ts->spi->irq);
222 }
223}
224
225
226static void __ads7846_disable(struct ads7846 *ts)
227{
228 ads7846_stop(ts);
229 regulator_disable(ts->reg);
230
231
232
233
234
235}
236
237
238static 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
249static 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
264static 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
283
284
285
286
287struct 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
296
297
298 __be16 sample ____cacheline_aligned;
299};
300
301struct ads7845_ser_req {
302 u8 command[3];
303 struct spi_message msg;
304 struct spi_transfer xfer[2];
305
306
307
308
309 u8 sample[3] ____cacheline_aligned;
310};
311
312static 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
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
336 req->xfer[1].delay_usecs = ts->vref_delay_usecs;
337 spi_message_add_tail(&req->xfer[1], &req->msg);
338
339
340 command |= ADS_PD10_REF_ON;
341 }
342
343
344 command |= ADS_PD10_ADC_ON;
345
346
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
357
358
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
377 status = be16_to_cpu(req->sample);
378 status = status >> 3;
379 status &= 0x0fff;
380 }
381
382 kfree(req);
383 return status;
384}
385
386static 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
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 \
425name ## _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} \
434static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
435
436
437
438
439
440
441
442static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
443{
444 return v;
445}
446
447SHOW(temp0, temp0, null_adjust)
448SHOW(temp1, temp1, null_adjust)
449
450
451
452
453
454
455static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
456{
457 unsigned retval = v;
458
459
460 retval *= ts->vref_mv;
461 retval = retval >> 12;
462
463 return retval;
464}
465
466static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
467{
468 unsigned retval = vaux_adjust(ts, v);
469
470
471 if (ts->model == 7846)
472 retval *= 4;
473
474 return retval;
475}
476
477SHOW(in0_input, vaux, vaux_adjust)
478SHOW(in1_input, vbatt, vbatt_adjust)
479
480static 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)
487 return 0;
488 if (ts->model == 7845 && index != 2)
489 return 0;
490
491 return attr->mode;
492}
493
494static struct attribute *ads7846_attributes[] = {
495 &dev_attr_temp0.attr,
496 &dev_attr_temp1.attr,
497 &dev_attr_in0_input.attr,
498 &dev_attr_in1_input.attr,
499 NULL,
500};
501
502static struct attribute_group ads7846_attr_group = {
503 .attrs = ads7846_attributes,
504 .is_visible = ads7846_is_visible,
505};
506__ATTRIBUTE_GROUPS(ads7846_attr);
507
508static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
509{
510
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 if (IS_ERR(ts->hwmon))
533 return PTR_ERR(ts->hwmon);
534
535 return 0;
536}
537
538static void ads784x_hwmon_unregister(struct spi_device *spi,
539 struct ads7846 *ts)
540{
541 if (ts->hwmon)
542 hwmon_device_unregister(ts->hwmon);
543}
544
545#else
546static inline int ads784x_hwmon_register(struct spi_device *spi,
547 struct ads7846 *ts)
548{
549 return 0;
550}
551
552static inline void ads784x_hwmon_unregister(struct spi_device *spi,
553 struct ads7846 *ts)
554{
555}
556#endif
557
558static ssize_t ads7846_pen_down_show(struct device *dev,
559 struct device_attribute *attr, char *buf)
560{
561 struct ads7846 *ts = dev_get_drvdata(dev);
562
563 return sprintf(buf, "%u\n", ts->pendown);
564}
565
566static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
567
568static ssize_t ads7846_disable_show(struct device *dev,
569 struct device_attribute *attr, char *buf)
570{
571 struct ads7846 *ts = dev_get_drvdata(dev);
572
573 return sprintf(buf, "%u\n", ts->disabled);
574}
575
576static ssize_t ads7846_disable_store(struct device *dev,
577 struct device_attribute *attr,
578 const char *buf, size_t count)
579{
580 struct ads7846 *ts = dev_get_drvdata(dev);
581 unsigned int i;
582 int err;
583
584 err = kstrtouint(buf, 10, &i);
585 if (err)
586 return err;
587
588 if (i)
589 ads7846_disable(ts);
590 else
591 ads7846_enable(ts);
592
593 return count;
594}
595
596static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
597
598static struct attribute *ads784x_attributes[] = {
599 &dev_attr_pen_down.attr,
600 &dev_attr_disable.attr,
601 NULL,
602};
603
604static struct attribute_group ads784x_attr_group = {
605 .attrs = ads784x_attributes,
606};
607
608
609
610static int get_pendown_state(struct ads7846 *ts)
611{
612 if (ts->get_pendown_state)
613 return ts->get_pendown_state();
614
615 return !gpio_get_value(ts->gpio_pendown);
616}
617
618static void null_wait_for_sync(void)
619{
620}
621
622static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
623{
624 struct ads7846 *ts = ads;
625
626 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
627
628 ts->read_rep = 0;
629
630
631
632
633 if (ts->read_cnt < ts->debounce_max) {
634 ts->last_read = *val;
635 ts->read_cnt++;
636 return ADS7846_FILTER_REPEAT;
637 } else {
638
639
640
641
642
643
644 ts->read_cnt = 0;
645 return ADS7846_FILTER_IGNORE;
646 }
647 } else {
648 if (++ts->read_rep > ts->debounce_rep) {
649
650
651
652
653 ts->read_cnt = 0;
654 ts->read_rep = 0;
655 return ADS7846_FILTER_OK;
656 } else {
657
658 ts->read_cnt++;
659 return ADS7846_FILTER_REPEAT;
660 }
661 }
662}
663
664static int ads7846_no_filter(void *ads, int data_idx, int *val)
665{
666 return ADS7846_FILTER_OK;
667}
668
669static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
670{
671 int value;
672 struct spi_transfer *t =
673 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
674
675 if (ts->model == 7845) {
676 value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1]));
677 } else {
678
679
680
681
682 value = be16_to_cpup((__be16 *)t->rx_buf);
683 }
684
685
686 return (value >> 3) & 0xfff;
687}
688
689static void ads7846_update_value(struct spi_message *m, int val)
690{
691 struct spi_transfer *t =
692 list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
693
694 *(u16 *)t->rx_buf = val;
695}
696
697static void ads7846_read_state(struct ads7846 *ts)
698{
699 struct ads7846_packet *packet = ts->packet;
700 struct spi_message *m;
701 int msg_idx = 0;
702 int val;
703 int action;
704 int error;
705
706 while (msg_idx < ts->msg_count) {
707
708 ts->wait_for_sync();
709
710 m = &ts->msg[msg_idx];
711 error = spi_sync(ts->spi, m);
712 if (error) {
713 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
714 packet->tc.ignore = true;
715 return;
716 }
717
718
719
720
721
722 if (msg_idx < ts->msg_count - 1) {
723
724 val = ads7846_get_value(ts, m);
725
726 action = ts->filter(ts->filter_data, msg_idx, &val);
727 switch (action) {
728 case ADS7846_FILTER_REPEAT:
729 continue;
730
731 case ADS7846_FILTER_IGNORE:
732 packet->tc.ignore = true;
733 msg_idx = ts->msg_count - 1;
734 continue;
735
736 case ADS7846_FILTER_OK:
737 ads7846_update_value(m, val);
738 packet->tc.ignore = false;
739 msg_idx++;
740 break;
741
742 default:
743 BUG();
744 }
745 } else {
746 msg_idx++;
747 }
748 }
749}
750
751static void ads7846_report_state(struct ads7846 *ts)
752{
753 struct ads7846_packet *packet = ts->packet;
754 unsigned int Rt;
755 u16 x, y, z1, z2;
756
757
758
759
760
761
762 if (ts->model == 7845) {
763 x = *(u16 *)packet->tc.x_buf;
764 y = *(u16 *)packet->tc.y_buf;
765 z1 = 0;
766 z2 = 0;
767 } else {
768 x = packet->tc.x;
769 y = packet->tc.y;
770 z1 = packet->tc.z1;
771 z2 = packet->tc.z2;
772 }
773
774
775 if (x == MAX_12BIT)
776 x = 0;
777
778 if (ts->model == 7843) {
779 Rt = ts->pressure_max / 2;
780 } else if (ts->model == 7845) {
781 if (get_pendown_state(ts))
782 Rt = ts->pressure_max / 2;
783 else
784 Rt = 0;
785 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
786 } else if (likely(x && z1)) {
787
788 Rt = z2;
789 Rt -= z1;
790 Rt *= x;
791 Rt *= ts->x_plate_ohms;
792 Rt /= z1;
793 Rt = (Rt + 2047) >> 12;
794 } else {
795 Rt = 0;
796 }
797
798
799
800
801
802
803 if (packet->tc.ignore || Rt > ts->pressure_max) {
804 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
805 packet->tc.ignore, Rt);
806 return;
807 }
808
809
810
811
812
813 if (ts->penirq_recheck_delay_usecs) {
814 udelay(ts->penirq_recheck_delay_usecs);
815 if (!get_pendown_state(ts))
816 Rt = 0;
817 }
818
819
820
821
822
823
824
825
826
827
828 if (Rt) {
829 struct input_dev *input = ts->input;
830
831 if (ts->swap_xy)
832 swap(x, y);
833
834 if (!ts->pendown) {
835 input_report_key(input, BTN_TOUCH, 1);
836 ts->pendown = true;
837 dev_vdbg(&ts->spi->dev, "DOWN\n");
838 }
839
840 input_report_abs(input, ABS_X, x);
841 input_report_abs(input, ABS_Y, y);
842 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
843
844 input_sync(input);
845 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
846 }
847}
848
849static irqreturn_t ads7846_hard_irq(int irq, void *handle)
850{
851 struct ads7846 *ts = handle;
852
853 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
854}
855
856
857static irqreturn_t ads7846_irq(int irq, void *handle)
858{
859 struct ads7846 *ts = handle;
860
861
862 msleep(TS_POLL_DELAY);
863
864 while (!ts->stopped && get_pendown_state(ts)) {
865
866
867 ads7846_read_state(ts);
868
869 if (!ts->stopped)
870 ads7846_report_state(ts);
871
872 wait_event_timeout(ts->wait, ts->stopped,
873 msecs_to_jiffies(TS_POLL_PERIOD));
874 }
875
876 if (ts->pendown) {
877 struct input_dev *input = ts->input;
878
879 input_report_key(input, BTN_TOUCH, 0);
880 input_report_abs(input, ABS_PRESSURE, 0);
881 input_sync(input);
882
883 ts->pendown = false;
884 dev_vdbg(&ts->spi->dev, "UP\n");
885 }
886
887 return IRQ_HANDLED;
888}
889
890static int __maybe_unused ads7846_suspend(struct device *dev)
891{
892 struct ads7846 *ts = dev_get_drvdata(dev);
893
894 mutex_lock(&ts->lock);
895
896 if (!ts->suspended) {
897
898 if (!ts->disabled)
899 __ads7846_disable(ts);
900
901 if (device_may_wakeup(&ts->spi->dev))
902 enable_irq_wake(ts->spi->irq);
903
904 ts->suspended = true;
905 }
906
907 mutex_unlock(&ts->lock);
908
909 return 0;
910}
911
912static int __maybe_unused ads7846_resume(struct device *dev)
913{
914 struct ads7846 *ts = dev_get_drvdata(dev);
915
916 mutex_lock(&ts->lock);
917
918 if (ts->suspended) {
919
920 ts->suspended = false;
921
922 if (device_may_wakeup(&ts->spi->dev))
923 disable_irq_wake(ts->spi->irq);
924
925 if (!ts->disabled)
926 __ads7846_enable(ts);
927 }
928
929 mutex_unlock(&ts->lock);
930
931 return 0;
932}
933
934static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
935
936static int ads7846_setup_pendown(struct spi_device *spi,
937 struct ads7846 *ts,
938 const struct ads7846_platform_data *pdata)
939{
940 int err;
941
942
943
944
945
946
947
948 if (pdata->get_pendown_state) {
949 ts->get_pendown_state = pdata->get_pendown_state;
950 } else if (gpio_is_valid(pdata->gpio_pendown)) {
951
952 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
953 "ads7846_pendown");
954 if (err) {
955 dev_err(&spi->dev,
956 "failed to request/setup pendown GPIO%d: %d\n",
957 pdata->gpio_pendown, err);
958 return err;
959 }
960
961 ts->gpio_pendown = pdata->gpio_pendown;
962
963 if (pdata->gpio_pendown_debounce)
964 gpio_set_debounce(pdata->gpio_pendown,
965 pdata->gpio_pendown_debounce);
966 } else {
967 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
968 return -EINVAL;
969 }
970
971 return 0;
972}
973
974
975
976
977
978static void ads7846_setup_spi_msg(struct ads7846 *ts,
979 const struct ads7846_platform_data *pdata)
980{
981 struct spi_message *m = &ts->msg[0];
982 struct spi_transfer *x = ts->xfer;
983 struct ads7846_packet *packet = ts->packet;
984 int vref = pdata->keep_vref_on;
985
986 if (ts->model == 7873) {
987
988
989
990
991
992 ts->model = 7846;
993 vref = 0;
994 }
995
996 ts->msg_count = 1;
997 spi_message_init(m);
998 m->context = ts;
999
1000 if (ts->model == 7845) {
1001 packet->read_y_cmd[0] = READ_Y(vref);
1002 packet->read_y_cmd[1] = 0;
1003 packet->read_y_cmd[2] = 0;
1004 x->tx_buf = &packet->read_y_cmd[0];
1005 x->rx_buf = &packet->tc.y_buf[0];
1006 x->len = 3;
1007 spi_message_add_tail(x, m);
1008 } else {
1009
1010 packet->read_y = READ_Y(vref);
1011 x->tx_buf = &packet->read_y;
1012 x->len = 1;
1013 spi_message_add_tail(x, m);
1014
1015 x++;
1016 x->rx_buf = &packet->tc.y;
1017 x->len = 2;
1018 spi_message_add_tail(x, m);
1019 }
1020
1021
1022
1023
1024
1025
1026 if (pdata->settle_delay_usecs) {
1027 x->delay_usecs = pdata->settle_delay_usecs;
1028
1029 x++;
1030 x->tx_buf = &packet->read_y;
1031 x->len = 1;
1032 spi_message_add_tail(x, m);
1033
1034 x++;
1035 x->rx_buf = &packet->tc.y;
1036 x->len = 2;
1037 spi_message_add_tail(x, m);
1038 }
1039
1040 ts->msg_count++;
1041 m++;
1042 spi_message_init(m);
1043 m->context = ts;
1044
1045 if (ts->model == 7845) {
1046 x++;
1047 packet->read_x_cmd[0] = READ_X(vref);
1048 packet->read_x_cmd[1] = 0;
1049 packet->read_x_cmd[2] = 0;
1050 x->tx_buf = &packet->read_x_cmd[0];
1051 x->rx_buf = &packet->tc.x_buf[0];
1052 x->len = 3;
1053 spi_message_add_tail(x, m);
1054 } else {
1055
1056 x++;
1057 packet->read_x = READ_X(vref);
1058 x->tx_buf = &packet->read_x;
1059 x->len = 1;
1060 spi_message_add_tail(x, m);
1061
1062 x++;
1063 x->rx_buf = &packet->tc.x;
1064 x->len = 2;
1065 spi_message_add_tail(x, m);
1066 }
1067
1068
1069 if (pdata->settle_delay_usecs) {
1070 x->delay_usecs = pdata->settle_delay_usecs;
1071
1072 x++;
1073 x->tx_buf = &packet->read_x;
1074 x->len = 1;
1075 spi_message_add_tail(x, m);
1076
1077 x++;
1078 x->rx_buf = &packet->tc.x;
1079 x->len = 2;
1080 spi_message_add_tail(x, m);
1081 }
1082
1083
1084 if (ts->model == 7846) {
1085 ts->msg_count++;
1086 m++;
1087 spi_message_init(m);
1088 m->context = ts;
1089
1090 x++;
1091 packet->read_z1 = READ_Z1(vref);
1092 x->tx_buf = &packet->read_z1;
1093 x->len = 1;
1094 spi_message_add_tail(x, m);
1095
1096 x++;
1097 x->rx_buf = &packet->tc.z1;
1098 x->len = 2;
1099 spi_message_add_tail(x, m);
1100
1101
1102 if (pdata->settle_delay_usecs) {
1103 x->delay_usecs = pdata->settle_delay_usecs;
1104
1105 x++;
1106 x->tx_buf = &packet->read_z1;
1107 x->len = 1;
1108 spi_message_add_tail(x, m);
1109
1110 x++;
1111 x->rx_buf = &packet->tc.z1;
1112 x->len = 2;
1113 spi_message_add_tail(x, m);
1114 }
1115
1116 ts->msg_count++;
1117 m++;
1118 spi_message_init(m);
1119 m->context = ts;
1120
1121 x++;
1122 packet->read_z2 = READ_Z2(vref);
1123 x->tx_buf = &packet->read_z2;
1124 x->len = 1;
1125 spi_message_add_tail(x, m);
1126
1127 x++;
1128 x->rx_buf = &packet->tc.z2;
1129 x->len = 2;
1130 spi_message_add_tail(x, m);
1131
1132
1133 if (pdata->settle_delay_usecs) {
1134 x->delay_usecs = pdata->settle_delay_usecs;
1135
1136 x++;
1137 x->tx_buf = &packet->read_z2;
1138 x->len = 1;
1139 spi_message_add_tail(x, m);
1140
1141 x++;
1142 x->rx_buf = &packet->tc.z2;
1143 x->len = 2;
1144 spi_message_add_tail(x, m);
1145 }
1146 }
1147
1148
1149 ts->msg_count++;
1150 m++;
1151 spi_message_init(m);
1152 m->context = ts;
1153
1154 if (ts->model == 7845) {
1155 x++;
1156 packet->pwrdown_cmd[0] = PWRDOWN;
1157 packet->pwrdown_cmd[1] = 0;
1158 packet->pwrdown_cmd[2] = 0;
1159 x->tx_buf = &packet->pwrdown_cmd[0];
1160 x->len = 3;
1161 } else {
1162 x++;
1163 packet->pwrdown = PWRDOWN;
1164 x->tx_buf = &packet->pwrdown;
1165 x->len = 1;
1166 spi_message_add_tail(x, m);
1167
1168 x++;
1169 x->rx_buf = &packet->dummy;
1170 x->len = 2;
1171 }
1172
1173 CS_CHANGE(*x);
1174 spi_message_add_tail(x, m);
1175}
1176
1177#ifdef CONFIG_OF
1178static const struct of_device_id ads7846_dt_ids[] = {
1179 { .compatible = "ti,tsc2046", .data = (void *) 7846 },
1180 { .compatible = "ti,ads7843", .data = (void *) 7843 },
1181 { .compatible = "ti,ads7845", .data = (void *) 7845 },
1182 { .compatible = "ti,ads7846", .data = (void *) 7846 },
1183 { .compatible = "ti,ads7873", .data = (void *) 7873 },
1184 { }
1185};
1186MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1187
1188static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1189{
1190 struct ads7846_platform_data *pdata;
1191 struct device_node *node = dev->of_node;
1192 const struct of_device_id *match;
1193
1194 if (!node) {
1195 dev_err(dev, "Device does not have associated DT data\n");
1196 return ERR_PTR(-EINVAL);
1197 }
1198
1199 match = of_match_device(ads7846_dt_ids, dev);
1200 if (!match) {
1201 dev_err(dev, "Unknown device model\n");
1202 return ERR_PTR(-EINVAL);
1203 }
1204
1205 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1206 if (!pdata)
1207 return ERR_PTR(-ENOMEM);
1208
1209 pdata->model = (unsigned long)match->data;
1210
1211 of_property_read_u16(node, "ti,vref-delay-usecs",
1212 &pdata->vref_delay_usecs);
1213 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
1214 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
1215
1216 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
1217
1218 of_property_read_u16(node, "ti,settle-delay-usec",
1219 &pdata->settle_delay_usecs);
1220 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
1221 &pdata->penirq_recheck_delay_usecs);
1222
1223 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1224 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1225
1226 of_property_read_u16(node, "ti,x-min", &pdata->x_min);
1227 of_property_read_u16(node, "ti,y-min", &pdata->y_min);
1228 of_property_read_u16(node, "ti,x-max", &pdata->x_max);
1229 of_property_read_u16(node, "ti,y-max", &pdata->y_max);
1230
1231 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1232 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1233
1234 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1235 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1236 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1237
1238 of_property_read_u32(node, "ti,pendown-gpio-debounce",
1239 &pdata->gpio_pendown_debounce);
1240
1241 pdata->wakeup = of_property_read_bool(node, "wakeup-source") ||
1242 of_property_read_bool(node, "linux,wakeup");
1243
1244 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1245
1246 return pdata;
1247}
1248#else
1249static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1250{
1251 dev_err(dev, "no platform data defined\n");
1252 return ERR_PTR(-EINVAL);
1253}
1254#endif
1255
1256static int ads7846_probe(struct spi_device *spi)
1257{
1258 const struct ads7846_platform_data *pdata;
1259 struct ads7846 *ts;
1260 struct ads7846_packet *packet;
1261 struct input_dev *input_dev;
1262 unsigned long irq_flags;
1263 int err;
1264
1265 if (!spi->irq) {
1266 dev_dbg(&spi->dev, "no IRQ?\n");
1267 return -EINVAL;
1268 }
1269
1270
1271 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1272 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1273 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1274 return -EINVAL;
1275 }
1276
1277
1278
1279
1280
1281
1282 spi->bits_per_word = 8;
1283 spi->mode = SPI_MODE_0;
1284 err = spi_setup(spi);
1285 if (err < 0)
1286 return err;
1287
1288 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1289 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1290 input_dev = input_allocate_device();
1291 if (!ts || !packet || !input_dev) {
1292 err = -ENOMEM;
1293 goto err_free_mem;
1294 }
1295
1296 spi_set_drvdata(spi, ts);
1297
1298 ts->packet = packet;
1299 ts->spi = spi;
1300 ts->input = input_dev;
1301
1302 mutex_init(&ts->lock);
1303 init_waitqueue_head(&ts->wait);
1304
1305 pdata = dev_get_platdata(&spi->dev);
1306 if (!pdata) {
1307 pdata = ads7846_probe_dt(&spi->dev);
1308 if (IS_ERR(pdata)) {
1309 err = PTR_ERR(pdata);
1310 goto err_free_mem;
1311 }
1312 }
1313
1314 ts->model = pdata->model ? : 7846;
1315 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1316 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1317 ts->pressure_max = pdata->pressure_max ? : ~0;
1318
1319 ts->vref_mv = pdata->vref_mv;
1320 ts->swap_xy = pdata->swap_xy;
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 ads7846_setup_spi_msg(ts, pdata);
1373
1374 ts->reg = regulator_get(&spi->dev, "vcc");
1375 if (IS_ERR(ts->reg)) {
1376 err = PTR_ERR(ts->reg);
1377 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1378 goto err_free_gpio;
1379 }
1380
1381 err = regulator_enable(ts->reg);
1382 if (err) {
1383 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1384 goto err_put_regulator;
1385 }
1386
1387 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1388 irq_flags |= IRQF_ONESHOT;
1389
1390 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1391 irq_flags, spi->dev.driver->name, ts);
1392 if (err && !pdata->irq_flags) {
1393 dev_info(&spi->dev,
1394 "trying pin change workaround on irq %d\n", spi->irq);
1395 irq_flags |= IRQF_TRIGGER_RISING;
1396 err = request_threaded_irq(spi->irq,
1397 ads7846_hard_irq, ads7846_irq,
1398 irq_flags, spi->dev.driver->name, ts);
1399 }
1400
1401 if (err) {
1402 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1403 goto err_disable_regulator;
1404 }
1405
1406 err = ads784x_hwmon_register(spi, ts);
1407 if (err)
1408 goto err_free_irq;
1409
1410 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1411
1412
1413
1414
1415
1416 if (ts->model == 7845)
1417 ads7845_read12_ser(&spi->dev, PWRDOWN);
1418 else
1419 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1420
1421 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1422 if (err)
1423 goto err_remove_hwmon;
1424
1425 err = input_register_device(input_dev);
1426 if (err)
1427 goto err_remove_attr_group;
1428
1429 device_init_wakeup(&spi->dev, pdata->wakeup);
1430
1431
1432
1433
1434
1435 if (!dev_get_platdata(&spi->dev))
1436 devm_kfree(&spi->dev, (void *)pdata);
1437
1438 return 0;
1439
1440 err_remove_attr_group:
1441 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1442 err_remove_hwmon:
1443 ads784x_hwmon_unregister(spi, ts);
1444 err_free_irq:
1445 free_irq(spi->irq, ts);
1446 err_disable_regulator:
1447 regulator_disable(ts->reg);
1448 err_put_regulator:
1449 regulator_put(ts->reg);
1450 err_free_gpio:
1451 if (!ts->get_pendown_state)
1452 gpio_free(ts->gpio_pendown);
1453 err_cleanup_filter:
1454 if (ts->filter_cleanup)
1455 ts->filter_cleanup(ts->filter_data);
1456 err_free_mem:
1457 input_free_device(input_dev);
1458 kfree(packet);
1459 kfree(ts);
1460 return err;
1461}
1462
1463static int ads7846_remove(struct spi_device *spi)
1464{
1465 struct ads7846 *ts = spi_get_drvdata(spi);
1466
1467 device_init_wakeup(&spi->dev, false);
1468
1469 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1470
1471 ads7846_disable(ts);
1472 free_irq(ts->spi->irq, ts);
1473
1474 input_unregister_device(ts->input);
1475
1476 ads784x_hwmon_unregister(spi, ts);
1477
1478 regulator_disable(ts->reg);
1479 regulator_put(ts->reg);
1480
1481 if (!ts->get_pendown_state) {
1482
1483
1484
1485
1486 gpio_free(ts->gpio_pendown);
1487 }
1488
1489 if (ts->filter_cleanup)
1490 ts->filter_cleanup(ts->filter_data);
1491
1492 kfree(ts->packet);
1493 kfree(ts);
1494
1495 dev_dbg(&spi->dev, "unregistered touchscreen\n");
1496
1497 return 0;
1498}
1499
1500static struct spi_driver ads7846_driver = {
1501 .driver = {
1502 .name = "ads7846",
1503 .owner = THIS_MODULE,
1504 .pm = &ads7846_pm,
1505 .of_match_table = of_match_ptr(ads7846_dt_ids),
1506 },
1507 .probe = ads7846_probe,
1508 .remove = ads7846_remove,
1509};
1510
1511module_spi_driver(ads7846_driver);
1512
1513MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1514MODULE_LICENSE("GPL");
1515MODULE_ALIAS("spi:ads7846");
1516