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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/unaligned.h>
36
37
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56
57
58
59#define TS_POLL_DELAY 1
60#define TS_POLL_PERIOD 5
61
62
63#define SAMPLE_BITS (8 + 16 + 2 )
64
65struct ads7846_buf {
66 u8 cmd;
67 __be16 data;
68} __packed;
69
70struct ads7846_buf_layout {
71 unsigned int offset;
72 unsigned int count;
73 unsigned int skip;
74};
75
76
77
78
79
80
81struct ads7846_packet {
82 unsigned int count;
83 unsigned int count_skip;
84 unsigned int cmds;
85 unsigned int last_cmd_idx;
86 struct ads7846_buf_layout l[5];
87 struct ads7846_buf *rx;
88 struct ads7846_buf *tx;
89
90 struct ads7846_buf pwrdown_cmd;
91
92 bool ignore;
93 u16 x, y, z1, z2;
94};
95
96struct ads7846 {
97 struct input_dev *input;
98 char phys[32];
99 char name[32];
100
101 struct spi_device *spi;
102 struct regulator *reg;
103
104#if IS_ENABLED(CONFIG_HWMON)
105 struct device *hwmon;
106#endif
107
108 u16 model;
109 u16 vref_mv;
110 u16 vref_delay_usecs;
111 u16 x_plate_ohms;
112 u16 pressure_max;
113
114 bool swap_xy;
115 bool use_internal;
116
117 struct ads7846_packet *packet;
118
119 struct spi_transfer xfer[18];
120 struct spi_message msg[5];
121 int msg_count;
122 wait_queue_head_t wait;
123
124 bool pendown;
125
126 int read_cnt;
127 int read_rep;
128 int last_read;
129
130 u16 debounce_max;
131 u16 debounce_tol;
132 u16 debounce_rep;
133
134 u16 penirq_recheck_delay_usecs;
135
136 struct touchscreen_properties core_prop;
137
138 struct mutex lock;
139 bool stopped;
140 bool disabled;
141 bool suspended;
142
143 int (*filter)(void *data, int data_idx, int *val);
144 void *filter_data;
145 void (*filter_cleanup)(void *data);
146 int (*get_pendown_state)(void);
147 int gpio_pendown;
148
149 void (*wait_for_sync)(void);
150};
151
152
153#if 0
154#define CS_CHANGE(xfer) ((xfer).cs_change = 1)
155#else
156#define CS_CHANGE(xfer) ((xfer).cs_change = 0)
157#endif
158
159
160
161
162
163
164#define ADS_START (1 << 7)
165#define ADS_A2A1A0_d_y (1 << 4)
166#define ADS_A2A1A0_d_z1 (3 << 4)
167#define ADS_A2A1A0_d_z2 (4 << 4)
168#define ADS_A2A1A0_d_x (5 << 4)
169#define ADS_A2A1A0_temp0 (0 << 4)
170#define ADS_A2A1A0_vbatt (2 << 4)
171#define ADS_A2A1A0_vaux (6 << 4)
172#define ADS_A2A1A0_temp1 (7 << 4)
173#define ADS_8_BIT (1 << 3)
174#define ADS_12_BIT (0 << 3)
175#define ADS_SER (1 << 2)
176#define ADS_DFR (0 << 2)
177#define ADS_PD10_PDOWN (0 << 0)
178#define ADS_PD10_ADC_ON (1 << 0)
179#define ADS_PD10_REF_ON (2 << 0)
180#define ADS_PD10_ALL_ON (3 << 0)
181
182#define MAX_12BIT ((1<<12)-1)
183
184
185#define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
186 | ADS_12_BIT | ADS_DFR | \
187 (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
188
189#define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref))
190#define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref))
191#define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref))
192#define READ_X(vref) (READ_12BIT_DFR(x, 1, vref))
193#define PWRDOWN (READ_12BIT_DFR(y, 0, 0))
194
195
196
197
198#define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
199 | ADS_12_BIT | ADS_SER)
200
201#define REF_ON (READ_12BIT_DFR(x, 1, 1))
202#define REF_OFF (READ_12BIT_DFR(y, 0, 0))
203
204
205
206
207
208
209
210
211enum ads7846_cmds {
212 ADS7846_X,
213 ADS7846_Y,
214 ADS7846_Z1,
215 ADS7846_Z2,
216 ADS7846_PWDOWN,
217};
218
219static int get_pendown_state(struct ads7846 *ts)
220{
221 if (ts->get_pendown_state)
222 return ts->get_pendown_state();
223
224 return !gpio_get_value(ts->gpio_pendown);
225}
226
227static void ads7846_report_pen_up(struct ads7846 *ts)
228{
229 struct input_dev *input = ts->input;
230
231 input_report_key(input, BTN_TOUCH, 0);
232 input_report_abs(input, ABS_PRESSURE, 0);
233 input_sync(input);
234
235 ts->pendown = false;
236 dev_vdbg(&ts->spi->dev, "UP\n");
237}
238
239
240static void ads7846_stop(struct ads7846 *ts)
241{
242 if (!ts->disabled && !ts->suspended) {
243
244 ts->stopped = true;
245 mb();
246 wake_up(&ts->wait);
247 disable_irq(ts->spi->irq);
248 }
249}
250
251
252static void ads7846_restart(struct ads7846 *ts)
253{
254 if (!ts->disabled && !ts->suspended) {
255
256 if (ts->pendown && !get_pendown_state(ts))
257 ads7846_report_pen_up(ts);
258
259
260 ts->stopped = false;
261 mb();
262 enable_irq(ts->spi->irq);
263 }
264}
265
266
267static void __ads7846_disable(struct ads7846 *ts)
268{
269 ads7846_stop(ts);
270 regulator_disable(ts->reg);
271
272
273
274
275
276}
277
278
279static void __ads7846_enable(struct ads7846 *ts)
280{
281 int error;
282
283 error = regulator_enable(ts->reg);
284 if (error != 0)
285 dev_err(&ts->spi->dev, "Failed to enable supply: %d\n", error);
286
287 ads7846_restart(ts);
288}
289
290static void ads7846_disable(struct ads7846 *ts)
291{
292 mutex_lock(&ts->lock);
293
294 if (!ts->disabled) {
295
296 if (!ts->suspended)
297 __ads7846_disable(ts);
298
299 ts->disabled = true;
300 }
301
302 mutex_unlock(&ts->lock);
303}
304
305static void ads7846_enable(struct ads7846 *ts)
306{
307 mutex_lock(&ts->lock);
308
309 if (ts->disabled) {
310
311 ts->disabled = false;
312
313 if (!ts->suspended)
314 __ads7846_enable(ts);
315 }
316
317 mutex_unlock(&ts->lock);
318}
319
320
321
322
323
324
325
326
327
328struct ser_req {
329 u8 ref_on;
330 u8 command;
331 u8 ref_off;
332 u16 scratch;
333 struct spi_message msg;
334 struct spi_transfer xfer[6];
335
336
337
338
339 __be16 sample ____cacheline_aligned;
340};
341
342struct ads7845_ser_req {
343 u8 command[3];
344 struct spi_message msg;
345 struct spi_transfer xfer[2];
346
347
348
349
350 u8 sample[3] ____cacheline_aligned;
351};
352
353static int ads7846_read12_ser(struct device *dev, unsigned command)
354{
355 struct spi_device *spi = to_spi_device(dev);
356 struct ads7846 *ts = dev_get_drvdata(dev);
357 struct ser_req *req;
358 int status;
359
360 req = kzalloc(sizeof *req, GFP_KERNEL);
361 if (!req)
362 return -ENOMEM;
363
364 spi_message_init(&req->msg);
365
366
367 if (ts->use_internal) {
368 req->ref_on = REF_ON;
369 req->xfer[0].tx_buf = &req->ref_on;
370 req->xfer[0].len = 1;
371 spi_message_add_tail(&req->xfer[0], &req->msg);
372
373 req->xfer[1].rx_buf = &req->scratch;
374 req->xfer[1].len = 2;
375
376
377 req->xfer[1].delay.value = ts->vref_delay_usecs;
378 req->xfer[1].delay.unit = SPI_DELAY_UNIT_USECS;
379 spi_message_add_tail(&req->xfer[1], &req->msg);
380
381
382 command |= ADS_PD10_REF_ON;
383 }
384
385
386 command |= ADS_PD10_ADC_ON;
387
388
389 req->command = (u8) command;
390 req->xfer[2].tx_buf = &req->command;
391 req->xfer[2].len = 1;
392 spi_message_add_tail(&req->xfer[2], &req->msg);
393
394 req->xfer[3].rx_buf = &req->sample;
395 req->xfer[3].len = 2;
396 spi_message_add_tail(&req->xfer[3], &req->msg);
397
398
399
400
401 req->ref_off = PWRDOWN;
402 req->xfer[4].tx_buf = &req->ref_off;
403 req->xfer[4].len = 1;
404 spi_message_add_tail(&req->xfer[4], &req->msg);
405
406 req->xfer[5].rx_buf = &req->scratch;
407 req->xfer[5].len = 2;
408 CS_CHANGE(req->xfer[5]);
409 spi_message_add_tail(&req->xfer[5], &req->msg);
410
411 mutex_lock(&ts->lock);
412 ads7846_stop(ts);
413 status = spi_sync(spi, &req->msg);
414 ads7846_restart(ts);
415 mutex_unlock(&ts->lock);
416
417 if (status == 0) {
418
419 status = be16_to_cpu(req->sample);
420 status = status >> 3;
421 status &= 0x0fff;
422 }
423
424 kfree(req);
425 return status;
426}
427
428static int ads7845_read12_ser(struct device *dev, unsigned command)
429{
430 struct spi_device *spi = to_spi_device(dev);
431 struct ads7846 *ts = dev_get_drvdata(dev);
432 struct ads7845_ser_req *req;
433 int status;
434
435 req = kzalloc(sizeof *req, GFP_KERNEL);
436 if (!req)
437 return -ENOMEM;
438
439 spi_message_init(&req->msg);
440
441 req->command[0] = (u8) command;
442 req->xfer[0].tx_buf = req->command;
443 req->xfer[0].rx_buf = req->sample;
444 req->xfer[0].len = 3;
445 spi_message_add_tail(&req->xfer[0], &req->msg);
446
447 mutex_lock(&ts->lock);
448 ads7846_stop(ts);
449 status = spi_sync(spi, &req->msg);
450 ads7846_restart(ts);
451 mutex_unlock(&ts->lock);
452
453 if (status == 0) {
454
455 status = get_unaligned_be16(&req->sample[1]);
456 status = status >> 3;
457 status &= 0x0fff;
458 }
459
460 kfree(req);
461 return status;
462}
463
464#if IS_ENABLED(CONFIG_HWMON)
465
466#define SHOW(name, var, adjust) static ssize_t \
467name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
468{ \
469 struct ads7846 *ts = dev_get_drvdata(dev); \
470 ssize_t v = ads7846_read12_ser(&ts->spi->dev, \
471 READ_12BIT_SER(var)); \
472 if (v < 0) \
473 return v; \
474 return sprintf(buf, "%u\n", adjust(ts, v)); \
475} \
476static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
477
478
479
480
481
482
483
484static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
485{
486 return v;
487}
488
489SHOW(temp0, temp0, null_adjust)
490SHOW(temp1, temp1, null_adjust)
491
492
493
494
495
496
497static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
498{
499 unsigned retval = v;
500
501
502 retval *= ts->vref_mv;
503 retval = retval >> 12;
504
505 return retval;
506}
507
508static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
509{
510 unsigned retval = vaux_adjust(ts, v);
511
512
513 if (ts->model == 7846)
514 retval *= 4;
515
516 return retval;
517}
518
519SHOW(in0_input, vaux, vaux_adjust)
520SHOW(in1_input, vbatt, vbatt_adjust)
521
522static umode_t ads7846_is_visible(struct kobject *kobj, struct attribute *attr,
523 int index)
524{
525 struct device *dev = kobj_to_dev(kobj);
526 struct ads7846 *ts = dev_get_drvdata(dev);
527
528 if (ts->model == 7843 && index < 2)
529 return 0;
530 if (ts->model == 7845 && index != 2)
531 return 0;
532
533 return attr->mode;
534}
535
536static struct attribute *ads7846_attributes[] = {
537 &dev_attr_temp0.attr,
538 &dev_attr_temp1.attr,
539 &dev_attr_in0_input.attr,
540 &dev_attr_in1_input.attr,
541 NULL,
542};
543
544static const struct attribute_group ads7846_attr_group = {
545 .attrs = ads7846_attributes,
546 .is_visible = ads7846_is_visible,
547};
548__ATTRIBUTE_GROUPS(ads7846_attr);
549
550static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
551{
552
553 switch (ts->model) {
554 case 7846:
555 if (!ts->vref_mv) {
556 dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
557 ts->vref_mv = 2500;
558 ts->use_internal = true;
559 }
560 break;
561 case 7845:
562 case 7843:
563 if (!ts->vref_mv) {
564 dev_warn(&spi->dev,
565 "external vREF for ADS%d not specified\n",
566 ts->model);
567 return 0;
568 }
569 break;
570 }
571
572 ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias,
573 ts, ads7846_attr_groups);
574
575 return PTR_ERR_OR_ZERO(ts->hwmon);
576}
577
578static void ads784x_hwmon_unregister(struct spi_device *spi,
579 struct ads7846 *ts)
580{
581 if (ts->hwmon)
582 hwmon_device_unregister(ts->hwmon);
583}
584
585#else
586static inline int ads784x_hwmon_register(struct spi_device *spi,
587 struct ads7846 *ts)
588{
589 return 0;
590}
591
592static inline void ads784x_hwmon_unregister(struct spi_device *spi,
593 struct ads7846 *ts)
594{
595}
596#endif
597
598static ssize_t ads7846_pen_down_show(struct device *dev,
599 struct device_attribute *attr, char *buf)
600{
601 struct ads7846 *ts = dev_get_drvdata(dev);
602
603 return sprintf(buf, "%u\n", ts->pendown);
604}
605
606static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
607
608static ssize_t ads7846_disable_show(struct device *dev,
609 struct device_attribute *attr, char *buf)
610{
611 struct ads7846 *ts = dev_get_drvdata(dev);
612
613 return sprintf(buf, "%u\n", ts->disabled);
614}
615
616static ssize_t ads7846_disable_store(struct device *dev,
617 struct device_attribute *attr,
618 const char *buf, size_t count)
619{
620 struct ads7846 *ts = dev_get_drvdata(dev);
621 unsigned int i;
622 int err;
623
624 err = kstrtouint(buf, 10, &i);
625 if (err)
626 return err;
627
628 if (i)
629 ads7846_disable(ts);
630 else
631 ads7846_enable(ts);
632
633 return count;
634}
635
636static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
637
638static struct attribute *ads784x_attributes[] = {
639 &dev_attr_pen_down.attr,
640 &dev_attr_disable.attr,
641 NULL,
642};
643
644static const struct attribute_group ads784x_attr_group = {
645 .attrs = ads784x_attributes,
646};
647
648
649
650static void null_wait_for_sync(void)
651{
652}
653
654static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
655{
656 struct ads7846 *ts = ads;
657
658 if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
659
660 ts->read_rep = 0;
661
662
663
664
665 if (ts->read_cnt < ts->debounce_max) {
666 ts->last_read = *val;
667 ts->read_cnt++;
668 return ADS7846_FILTER_REPEAT;
669 } else {
670
671
672
673
674
675
676 ts->read_cnt = 0;
677 return ADS7846_FILTER_IGNORE;
678 }
679 } else {
680 if (++ts->read_rep > ts->debounce_rep) {
681
682
683
684
685 ts->read_cnt = 0;
686 ts->read_rep = 0;
687 return ADS7846_FILTER_OK;
688 } else {
689
690 ts->read_cnt++;
691 return ADS7846_FILTER_REPEAT;
692 }
693 }
694}
695
696static int ads7846_no_filter(void *ads, int data_idx, int *val)
697{
698 return ADS7846_FILTER_OK;
699}
700
701static int ads7846_get_value(struct ads7846_buf *buf)
702{
703 int value;
704
705 value = be16_to_cpup(&buf->data);
706
707
708 return (value >> 3) & 0xfff;
709}
710
711static void ads7846_set_cmd_val(struct ads7846 *ts, enum ads7846_cmds cmd_idx,
712 u16 val)
713{
714 struct ads7846_packet *packet = ts->packet;
715
716 switch (cmd_idx) {
717 case ADS7846_Y:
718 packet->y = val;
719 break;
720 case ADS7846_X:
721 packet->x = val;
722 break;
723 case ADS7846_Z1:
724 packet->z1 = val;
725 break;
726 case ADS7846_Z2:
727 packet->z2 = val;
728 break;
729 default:
730 WARN_ON_ONCE(1);
731 }
732}
733
734static u8 ads7846_get_cmd(enum ads7846_cmds cmd_idx, int vref)
735{
736 switch (cmd_idx) {
737 case ADS7846_Y:
738 return READ_Y(vref);
739 case ADS7846_X:
740 return READ_X(vref);
741
742
743 case ADS7846_Z1:
744 return READ_Z1(vref);
745 case ADS7846_Z2:
746 return READ_Z2(vref);
747 case ADS7846_PWDOWN:
748 return PWRDOWN;
749 default:
750 WARN_ON_ONCE(1);
751 }
752
753 return 0;
754}
755
756static bool ads7846_cmd_need_settle(enum ads7846_cmds cmd_idx)
757{
758 switch (cmd_idx) {
759 case ADS7846_X:
760 case ADS7846_Y:
761 case ADS7846_Z1:
762 case ADS7846_Z2:
763 return true;
764 case ADS7846_PWDOWN:
765 return false;
766 default:
767 WARN_ON_ONCE(1);
768 }
769
770 return false;
771}
772
773static int ads7846_filter(struct ads7846 *ts)
774{
775 struct ads7846_packet *packet = ts->packet;
776 int action;
777 int val;
778 unsigned int cmd_idx, b;
779
780 packet->ignore = false;
781 for (cmd_idx = packet->last_cmd_idx; cmd_idx < packet->cmds - 1; cmd_idx++) {
782 struct ads7846_buf_layout *l = &packet->l[cmd_idx];
783
784 packet->last_cmd_idx = cmd_idx;
785
786 for (b = l->skip; b < l->count; b++) {
787 val = ads7846_get_value(&packet->rx[l->offset + b]);
788
789 action = ts->filter(ts->filter_data, cmd_idx, &val);
790 if (action == ADS7846_FILTER_REPEAT) {
791 if (b == l->count - 1)
792 return -EAGAIN;
793 } else if (action == ADS7846_FILTER_OK) {
794 ads7846_set_cmd_val(ts, cmd_idx, val);
795 break;
796 } else {
797 packet->ignore = true;
798 return 0;
799 }
800 }
801 }
802
803 return 0;
804}
805
806static void ads7846_read_state(struct ads7846 *ts)
807{
808 struct ads7846_packet *packet = ts->packet;
809 struct spi_message *m;
810 int msg_idx = 0;
811 int error;
812
813 packet->last_cmd_idx = 0;
814
815 while (true) {
816 ts->wait_for_sync();
817
818 m = &ts->msg[msg_idx];
819 error = spi_sync(ts->spi, m);
820 if (error) {
821 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
822 packet->ignore = true;
823 return;
824 }
825
826 error = ads7846_filter(ts);
827 if (error)
828 continue;
829
830 return;
831 }
832}
833
834static void ads7846_report_state(struct ads7846 *ts)
835{
836 struct ads7846_packet *packet = ts->packet;
837 unsigned int Rt;
838 u16 x, y, z1, z2;
839
840 x = packet->x;
841 y = packet->y;
842 if (ts->model == 7845) {
843 z1 = 0;
844 z2 = 0;
845 } else {
846 z1 = packet->z1;
847 z2 = packet->z2;
848 }
849
850
851 if (x == MAX_12BIT)
852 x = 0;
853
854 if (ts->model == 7843) {
855 Rt = ts->pressure_max / 2;
856 } else if (ts->model == 7845) {
857 if (get_pendown_state(ts))
858 Rt = ts->pressure_max / 2;
859 else
860 Rt = 0;
861 dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
862 } else if (likely(x && z1)) {
863
864 Rt = z2;
865 Rt -= z1;
866 Rt *= ts->x_plate_ohms;
867 Rt = DIV_ROUND_CLOSEST(Rt, 16);
868 Rt *= x;
869 Rt /= z1;
870 Rt = DIV_ROUND_CLOSEST(Rt, 256);
871 } else {
872 Rt = 0;
873 }
874
875
876
877
878
879
880 if (packet->ignore || Rt > ts->pressure_max) {
881 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
882 packet->ignore, Rt);
883 return;
884 }
885
886
887
888
889
890 if (ts->penirq_recheck_delay_usecs) {
891 udelay(ts->penirq_recheck_delay_usecs);
892 if (!get_pendown_state(ts))
893 Rt = 0;
894 }
895
896
897
898
899
900
901
902
903
904
905 if (Rt) {
906 struct input_dev *input = ts->input;
907
908 if (!ts->pendown) {
909 input_report_key(input, BTN_TOUCH, 1);
910 ts->pendown = true;
911 dev_vdbg(&ts->spi->dev, "DOWN\n");
912 }
913
914 touchscreen_report_pos(input, &ts->core_prop, x, y, false);
915 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
916
917 input_sync(input);
918 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
919 }
920}
921
922static irqreturn_t ads7846_hard_irq(int irq, void *handle)
923{
924 struct ads7846 *ts = handle;
925
926 return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
927}
928
929
930static irqreturn_t ads7846_irq(int irq, void *handle)
931{
932 struct ads7846 *ts = handle;
933
934
935 msleep(TS_POLL_DELAY);
936
937 while (!ts->stopped && get_pendown_state(ts)) {
938
939
940 ads7846_read_state(ts);
941
942 if (!ts->stopped)
943 ads7846_report_state(ts);
944
945 wait_event_timeout(ts->wait, ts->stopped,
946 msecs_to_jiffies(TS_POLL_PERIOD));
947 }
948
949 if (ts->pendown && !ts->stopped)
950 ads7846_report_pen_up(ts);
951
952 return IRQ_HANDLED;
953}
954
955static int __maybe_unused ads7846_suspend(struct device *dev)
956{
957 struct ads7846 *ts = dev_get_drvdata(dev);
958
959 mutex_lock(&ts->lock);
960
961 if (!ts->suspended) {
962
963 if (!ts->disabled)
964 __ads7846_disable(ts);
965
966 if (device_may_wakeup(&ts->spi->dev))
967 enable_irq_wake(ts->spi->irq);
968
969 ts->suspended = true;
970 }
971
972 mutex_unlock(&ts->lock);
973
974 return 0;
975}
976
977static int __maybe_unused ads7846_resume(struct device *dev)
978{
979 struct ads7846 *ts = dev_get_drvdata(dev);
980
981 mutex_lock(&ts->lock);
982
983 if (ts->suspended) {
984
985 ts->suspended = false;
986
987 if (device_may_wakeup(&ts->spi->dev))
988 disable_irq_wake(ts->spi->irq);
989
990 if (!ts->disabled)
991 __ads7846_enable(ts);
992 }
993
994 mutex_unlock(&ts->lock);
995
996 return 0;
997}
998
999static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
1000
1001static int ads7846_setup_pendown(struct spi_device *spi,
1002 struct ads7846 *ts,
1003 const struct ads7846_platform_data *pdata)
1004{
1005 int err;
1006
1007
1008
1009
1010
1011
1012
1013 if (pdata->get_pendown_state) {
1014 ts->get_pendown_state = pdata->get_pendown_state;
1015 } else if (gpio_is_valid(pdata->gpio_pendown)) {
1016
1017 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
1018 "ads7846_pendown");
1019 if (err) {
1020 dev_err(&spi->dev,
1021 "failed to request/setup pendown GPIO%d: %d\n",
1022 pdata->gpio_pendown, err);
1023 return err;
1024 }
1025
1026 ts->gpio_pendown = pdata->gpio_pendown;
1027
1028 if (pdata->gpio_pendown_debounce)
1029 gpio_set_debounce(pdata->gpio_pendown,
1030 pdata->gpio_pendown_debounce);
1031 } else {
1032 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
1033 return -EINVAL;
1034 }
1035
1036 return 0;
1037}
1038
1039
1040
1041
1042
1043static int ads7846_setup_spi_msg(struct ads7846 *ts,
1044 const struct ads7846_platform_data *pdata)
1045{
1046 struct spi_message *m = &ts->msg[0];
1047 struct spi_transfer *x = ts->xfer;
1048 struct ads7846_packet *packet = ts->packet;
1049 int vref = pdata->keep_vref_on;
1050 unsigned int count, offset = 0;
1051 unsigned int cmd_idx, b;
1052 unsigned long time;
1053 size_t size = 0;
1054
1055
1056 time = NSEC_PER_SEC / ts->spi->max_speed_hz;
1057
1058 count = pdata->settle_delay_usecs * NSEC_PER_USEC / time;
1059 packet->count_skip = DIV_ROUND_UP(count, 24);
1060
1061 if (ts->debounce_max && ts->debounce_rep)
1062
1063
1064 packet->count = ts->debounce_rep + 2;
1065 else
1066 packet->count = 1;
1067
1068 if (ts->model == 7846)
1069 packet->cmds = 5;
1070 else
1071 packet->cmds = 3;
1072
1073 for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) {
1074 struct ads7846_buf_layout *l = &packet->l[cmd_idx];
1075 unsigned int max_count;
1076
1077 if (ads7846_cmd_need_settle(cmd_idx))
1078 max_count = packet->count + packet->count_skip;
1079 else
1080 max_count = packet->count;
1081
1082 l->offset = offset;
1083 offset += max_count;
1084 l->count = max_count;
1085 l->skip = packet->count_skip;
1086 size += sizeof(*packet->tx) * max_count;
1087 }
1088
1089 packet->tx = devm_kzalloc(&ts->spi->dev, size, GFP_KERNEL);
1090 if (!packet->tx)
1091 return -ENOMEM;
1092
1093 packet->rx = devm_kzalloc(&ts->spi->dev, size, GFP_KERNEL);
1094 if (!packet->rx)
1095 return -ENOMEM;
1096
1097 if (ts->model == 7873) {
1098
1099
1100
1101
1102
1103 ts->model = 7846;
1104 vref = 0;
1105 }
1106
1107 ts->msg_count = 1;
1108 spi_message_init(m);
1109 m->context = ts;
1110
1111 for (cmd_idx = 0; cmd_idx < packet->cmds; cmd_idx++) {
1112 struct ads7846_buf_layout *l = &packet->l[cmd_idx];
1113 u8 cmd = ads7846_get_cmd(cmd_idx, vref);
1114
1115 for (b = 0; b < l->count; b++)
1116 packet->tx[l->offset + b].cmd = cmd;
1117 }
1118
1119 x->tx_buf = packet->tx;
1120 x->rx_buf = packet->rx;
1121 x->len = size;
1122 spi_message_add_tail(x, m);
1123
1124 return 0;
1125}
1126
1127#ifdef CONFIG_OF
1128static const struct of_device_id ads7846_dt_ids[] = {
1129 { .compatible = "ti,tsc2046", .data = (void *) 7846 },
1130 { .compatible = "ti,ads7843", .data = (void *) 7843 },
1131 { .compatible = "ti,ads7845", .data = (void *) 7845 },
1132 { .compatible = "ti,ads7846", .data = (void *) 7846 },
1133 { .compatible = "ti,ads7873", .data = (void *) 7873 },
1134 { }
1135};
1136MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
1137
1138static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1139{
1140 struct ads7846_platform_data *pdata;
1141 struct device_node *node = dev->of_node;
1142 const struct of_device_id *match;
1143 u32 value;
1144
1145 if (!node) {
1146 dev_err(dev, "Device does not have associated DT data\n");
1147 return ERR_PTR(-EINVAL);
1148 }
1149
1150 match = of_match_device(ads7846_dt_ids, dev);
1151 if (!match) {
1152 dev_err(dev, "Unknown device model\n");
1153 return ERR_PTR(-EINVAL);
1154 }
1155
1156 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
1157 if (!pdata)
1158 return ERR_PTR(-ENOMEM);
1159
1160 pdata->model = (unsigned long)match->data;
1161
1162 of_property_read_u16(node, "ti,vref-delay-usecs",
1163 &pdata->vref_delay_usecs);
1164 of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
1165 pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
1166
1167 pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
1168
1169 of_property_read_u16(node, "ti,settle-delay-usec",
1170 &pdata->settle_delay_usecs);
1171 of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
1172 &pdata->penirq_recheck_delay_usecs);
1173
1174 of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
1175 of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
1176
1177 of_property_read_u16(node, "ti,x-min", &pdata->x_min);
1178 of_property_read_u16(node, "ti,y-min", &pdata->y_min);
1179 of_property_read_u16(node, "ti,x-max", &pdata->x_max);
1180 of_property_read_u16(node, "ti,y-max", &pdata->y_max);
1181
1182
1183
1184
1185
1186 of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
1187 if (!of_property_read_u32(node, "touchscreen-min-pressure", &value))
1188 pdata->pressure_min = (u16) value;
1189 of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
1190
1191 of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
1192 if (!of_property_read_u32(node, "touchscreen-average-samples", &value))
1193 pdata->debounce_max = (u16) value;
1194 of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
1195 of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
1196
1197 of_property_read_u32(node, "ti,pendown-gpio-debounce",
1198 &pdata->gpio_pendown_debounce);
1199
1200 pdata->wakeup = of_property_read_bool(node, "wakeup-source") ||
1201 of_property_read_bool(node, "linux,wakeup");
1202
1203 pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
1204
1205 return pdata;
1206}
1207#else
1208static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
1209{
1210 dev_err(dev, "no platform data defined\n");
1211 return ERR_PTR(-EINVAL);
1212}
1213#endif
1214
1215static int ads7846_probe(struct spi_device *spi)
1216{
1217 const struct ads7846_platform_data *pdata;
1218 struct ads7846 *ts;
1219 struct ads7846_packet *packet;
1220 struct input_dev *input_dev;
1221 unsigned long irq_flags;
1222 int err;
1223
1224 if (!spi->irq) {
1225 dev_dbg(&spi->dev, "no IRQ?\n");
1226 return -EINVAL;
1227 }
1228
1229
1230 if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
1231 dev_err(&spi->dev, "f(sample) %d KHz?\n",
1232 (spi->max_speed_hz/SAMPLE_BITS)/1000);
1233 return -EINVAL;
1234 }
1235
1236
1237
1238
1239
1240
1241 spi->bits_per_word = 8;
1242 spi->mode &= ~SPI_MODE_X_MASK;
1243 spi->mode |= SPI_MODE_0;
1244 err = spi_setup(spi);
1245 if (err < 0)
1246 return err;
1247
1248 ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
1249 packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
1250 input_dev = input_allocate_device();
1251 if (!ts || !packet || !input_dev) {
1252 err = -ENOMEM;
1253 goto err_free_mem;
1254 }
1255
1256 spi_set_drvdata(spi, ts);
1257
1258 ts->packet = packet;
1259 ts->spi = spi;
1260 ts->input = input_dev;
1261
1262 mutex_init(&ts->lock);
1263 init_waitqueue_head(&ts->wait);
1264
1265 pdata = dev_get_platdata(&spi->dev);
1266 if (!pdata) {
1267 pdata = ads7846_probe_dt(&spi->dev);
1268 if (IS_ERR(pdata)) {
1269 err = PTR_ERR(pdata);
1270 goto err_free_mem;
1271 }
1272 }
1273
1274 ts->model = pdata->model ? : 7846;
1275 ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
1276 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
1277 ts->vref_mv = pdata->vref_mv;
1278
1279 if (pdata->filter != NULL) {
1280 if (pdata->filter_init != NULL) {
1281 err = pdata->filter_init(pdata, &ts->filter_data);
1282 if (err < 0)
1283 goto err_free_mem;
1284 }
1285 ts->filter = pdata->filter;
1286 ts->filter_cleanup = pdata->filter_cleanup;
1287 } else if (pdata->debounce_max) {
1288 ts->debounce_max = pdata->debounce_max;
1289 if (ts->debounce_max < 2)
1290 ts->debounce_max = 2;
1291 ts->debounce_tol = pdata->debounce_tol;
1292 ts->debounce_rep = pdata->debounce_rep;
1293 ts->filter = ads7846_debounce_filter;
1294 ts->filter_data = ts;
1295 } else {
1296 ts->filter = ads7846_no_filter;
1297 }
1298
1299 err = ads7846_setup_pendown(spi, ts, pdata);
1300 if (err)
1301 goto err_cleanup_filter;
1302
1303 if (pdata->penirq_recheck_delay_usecs)
1304 ts->penirq_recheck_delay_usecs =
1305 pdata->penirq_recheck_delay_usecs;
1306
1307 ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
1308
1309 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
1310 snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
1311
1312 input_dev->name = ts->name;
1313 input_dev->phys = ts->phys;
1314 input_dev->dev.parent = &spi->dev;
1315
1316 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
1317 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
1318 input_set_abs_params(input_dev, ABS_X,
1319 pdata->x_min ? : 0,
1320 pdata->x_max ? : MAX_12BIT,
1321 0, 0);
1322 input_set_abs_params(input_dev, ABS_Y,
1323 pdata->y_min ? : 0,
1324 pdata->y_max ? : MAX_12BIT,
1325 0, 0);
1326 input_set_abs_params(input_dev, ABS_PRESSURE,
1327 pdata->pressure_min, pdata->pressure_max, 0, 0);
1328
1329
1330
1331
1332
1333
1334 touchscreen_parse_properties(ts->input, false, &ts->core_prop);
1335 ts->pressure_max = input_abs_get_max(input_dev, ABS_PRESSURE) ? : ~0;
1336
1337
1338
1339
1340
1341 if (!ts->core_prop.swap_x_y && pdata->swap_xy) {
1342 swap(input_dev->absinfo[ABS_X], input_dev->absinfo[ABS_Y]);
1343 ts->core_prop.swap_x_y = true;
1344 }
1345
1346 ads7846_setup_spi_msg(ts, pdata);
1347
1348 ts->reg = regulator_get(&spi->dev, "vcc");
1349 if (IS_ERR(ts->reg)) {
1350 err = PTR_ERR(ts->reg);
1351 dev_err(&spi->dev, "unable to get regulator: %d\n", err);
1352 goto err_free_gpio;
1353 }
1354
1355 err = regulator_enable(ts->reg);
1356 if (err) {
1357 dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
1358 goto err_put_regulator;
1359 }
1360
1361 irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
1362 irq_flags |= IRQF_ONESHOT;
1363
1364 err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
1365 irq_flags, spi->dev.driver->name, ts);
1366 if (err && !pdata->irq_flags) {
1367 dev_info(&spi->dev,
1368 "trying pin change workaround on irq %d\n", spi->irq);
1369 irq_flags |= IRQF_TRIGGER_RISING;
1370 err = request_threaded_irq(spi->irq,
1371 ads7846_hard_irq, ads7846_irq,
1372 irq_flags, spi->dev.driver->name, ts);
1373 }
1374
1375 if (err) {
1376 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
1377 goto err_disable_regulator;
1378 }
1379
1380 err = ads784x_hwmon_register(spi, ts);
1381 if (err)
1382 goto err_free_irq;
1383
1384 dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
1385
1386
1387
1388
1389
1390 if (ts->model == 7845)
1391 ads7845_read12_ser(&spi->dev, PWRDOWN);
1392 else
1393 (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux));
1394
1395 err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
1396 if (err)
1397 goto err_remove_hwmon;
1398
1399 err = input_register_device(input_dev);
1400 if (err)
1401 goto err_remove_attr_group;
1402
1403 device_init_wakeup(&spi->dev, pdata->wakeup);
1404
1405
1406
1407
1408
1409 if (!dev_get_platdata(&spi->dev))
1410 devm_kfree(&spi->dev, (void *)pdata);
1411
1412 return 0;
1413
1414 err_remove_attr_group:
1415 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1416 err_remove_hwmon:
1417 ads784x_hwmon_unregister(spi, ts);
1418 err_free_irq:
1419 free_irq(spi->irq, ts);
1420 err_disable_regulator:
1421 regulator_disable(ts->reg);
1422 err_put_regulator:
1423 regulator_put(ts->reg);
1424 err_free_gpio:
1425 if (!ts->get_pendown_state)
1426 gpio_free(ts->gpio_pendown);
1427 err_cleanup_filter:
1428 if (ts->filter_cleanup)
1429 ts->filter_cleanup(ts->filter_data);
1430 err_free_mem:
1431 input_free_device(input_dev);
1432 kfree(packet);
1433 kfree(ts);
1434 return err;
1435}
1436
1437static int ads7846_remove(struct spi_device *spi)
1438{
1439 struct ads7846 *ts = spi_get_drvdata(spi);
1440
1441 sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
1442
1443 ads7846_disable(ts);
1444 free_irq(ts->spi->irq, ts);
1445
1446 input_unregister_device(ts->input);
1447
1448 ads784x_hwmon_unregister(spi, ts);
1449
1450 regulator_put(ts->reg);
1451
1452 if (!ts->get_pendown_state) {
1453
1454
1455
1456
1457 gpio_free(ts->gpio_pendown);
1458 }
1459
1460 if (ts->filter_cleanup)
1461 ts->filter_cleanup(ts->filter_data);
1462
1463 kfree(ts->packet);
1464 kfree(ts);
1465
1466 dev_dbg(&spi->dev, "unregistered touchscreen\n");
1467
1468 return 0;
1469}
1470
1471static struct spi_driver ads7846_driver = {
1472 .driver = {
1473 .name = "ads7846",
1474 .pm = &ads7846_pm,
1475 .of_match_table = of_match_ptr(ads7846_dt_ids),
1476 },
1477 .probe = ads7846_probe,
1478 .remove = ads7846_remove,
1479};
1480
1481module_spi_driver(ads7846_driver);
1482
1483MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
1484MODULE_LICENSE("GPL");
1485MODULE_ALIAS("spi:ads7846");
1486