1/*
2 * Driver for Pixcir I2C touchscreen controllers.
3 *
4 * Copyright (C) 2010-2011 Pixcir, Inc.
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16#include <linux/delay.h>
17#include <linux/module.h>
18#include <linux/interrupt.h>
19#include <linux/slab.h>
20#include <linux/i2c.h>
21#include <linux/input.h>
22#include <linux/input/mt.h>
23#include <linux/input/touchscreen.h>
24#include <linux/gpio.h>
25#include <linux/gpio/consumer.h>
26#include <linux/of_device.h>
27#include <linux/platform_data/pixcir_i2c_ts.h>
28#include <asm/unaligned.h>
29
30#define PIXCIR_MAX_SLOTS 5 /* Max fingers supported by driver */
31
32struct pixcir_i2c_ts_data {
33 struct i2c_client *client;
34 struct input_dev *input;
35 struct gpio_desc *gpio_attb;
36 struct gpio_desc *gpio_reset;
37 struct gpio_desc *gpio_enable;
38 struct gpio_desc *gpio_wake;
39 const struct pixcir_i2c_chip_data *chip;
40 struct touchscreen_properties prop;
41 int max_fingers; /* Max fingers supported in this instance */
42 bool running;
43};
44
45struct pixcir_report_data {
46 int num_touches;
47 struct input_mt_pos pos[PIXCIR_MAX_SLOTS];
48 int ids[PIXCIR_MAX_SLOTS];
49};
50
51static void pixcir_ts_parse(struct pixcir_i2c_ts_data *tsdata,
52 struct pixcir_report_data *report)
53{
54 u8 rdbuf[2 + PIXCIR_MAX_SLOTS * 5];
55 u8 wrbuf[1] = { 0 };
56 u8 *bufptr;
57 u8 touch;
58 int ret, i;
59 int readsize;
60 const struct pixcir_i2c_chip_data *chip = tsdata->chip;
61
62 memset(report, 0, sizeof(struct pixcir_report_data));
63
64 i = chip->has_hw_ids ? 1 : 0;
65 readsize = 2 + tsdata->max_fingers * (4 + i);
66 if (readsize > sizeof(rdbuf))
67 readsize = sizeof(rdbuf);
68
69 ret = i2c_master_send(tsdata->client, wrbuf, sizeof(wrbuf));
70 if (ret != sizeof(wrbuf)) {
71 dev_err(&tsdata->client->dev,
72 "%s: i2c_master_send failed(), ret=%d\n",
73 __func__, ret);
74 return;
75 }
76
77 ret = i2c_master_recv(tsdata->client, rdbuf, readsize);
78 if (ret != readsize) {
79 dev_err(&tsdata->client->dev,
80 "%s: i2c_master_recv failed(), ret=%d\n",
81 __func__, ret);
82 return;
83 }
84
85 touch = rdbuf[0] & 0x7;
86 if (touch > tsdata->max_fingers)
87 touch = tsdata->max_fingers;
88
89 report->num_touches = touch;
90 bufptr = &rdbuf[2];
91
92 for (i = 0; i < touch; i++) {
93 touchscreen_set_mt_pos(&report->pos[i], &tsdata->prop,
94 get_unaligned_le16(bufptr),
95 get_unaligned_le16(bufptr + 2));
96 if (chip->has_hw_ids) {
97 report->ids[i] = bufptr[4];
98 bufptr = bufptr + 5;
99 } else {
100 bufptr = bufptr + 4;
101 }
102 }
103}
104
105static void pixcir_ts_report(struct pixcir_i2c_ts_data *ts,
106 struct pixcir_report_data *report)
107{
108 int slots[PIXCIR_MAX_SLOTS];
109 int n, i, slot;
110 struct device *dev = &ts->client->dev;
111 const struct pixcir_i2c_chip_data *chip = ts->chip;
112
113 n = report->num_touches;
114 if (n > PIXCIR_MAX_SLOTS)
115 n = PIXCIR_MAX_SLOTS;
116
117 if (!ts->chip->has_hw_ids)
118 input_mt_assign_slots(ts->input, slots, report->pos, n, 0);
119
120 for (i = 0; i < n; i++) {
121 if (chip->has_hw_ids) {
122 slot = input_mt_get_slot_by_key(ts->input,
123 report->ids[i]);
124 if (slot < 0) {
125 dev_dbg(dev, "no free slot for id 0x%x\n",
126 report->ids[i]);
127 continue;
128 }
129 } else {
130 slot = slots[i];
131 }
132
133 input_mt_slot(ts->input, slot);
134 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
135
136 input_report_abs(ts->input, ABS_MT_POSITION_X,
137 report->pos[i].x);
138 input_report_abs(ts->input, ABS_MT_POSITION_Y,
139 report->pos[i].y);
140
141 dev_dbg(dev, "%d: slot %d, x %d, y %d\n",
142 i, slot, report->pos[i].x, report->pos[i].y);
143 }
144
145 input_mt_sync_frame(ts->input);
146 input_sync(ts->input);
147}
148
149static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
150{
151 struct pixcir_i2c_ts_data *tsdata = dev_id;
152 struct pixcir_report_data report;
153
154 while (tsdata->running) {
155 /* parse packet */
156 pixcir_ts_parse(tsdata, &report);
157
158 /* report it */
159 pixcir_ts_report(tsdata, &report);
160
161 if (gpiod_get_value_cansleep(tsdata->gpio_attb)) {
162 if (report.num_touches) {
163 /*
164 * Last report with no finger up?
165 * Do it now then.
166 */
167 input_mt_sync_frame(tsdata->input);
168 input_sync(tsdata->input);
169 }
170 break;
171 }
172
173 msleep(20);
174 }
175
176 return IRQ_HANDLED;
177}
178
179static void pixcir_reset(struct pixcir_i2c_ts_data *tsdata)
180{
181 if (!IS_ERR_OR_NULL(tsdata->gpio_reset)) {
182 gpiod_set_value_cansleep(tsdata->gpio_reset, 1);
183 ndelay(100); /* datasheet section 1.2.3 says 80ns min. */
184 gpiod_set_value_cansleep(tsdata->gpio_reset, 0);
185 /* wait for controller ready. 100ms guess. */
186 msleep(100);
187 }
188}
189
190static int pixcir_set_power_mode(struct pixcir_i2c_ts_data *ts,
191 enum pixcir_power_mode mode)
192{
193 struct device *dev = &ts->client->dev;
194 int ret;
195
196 if (mode == PIXCIR_POWER_ACTIVE || mode == PIXCIR_POWER_IDLE) {
197 if (ts->gpio_wake)
198 gpiod_set_value_cansleep(ts->gpio_wake, 1);
199 }
200
201 ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_POWER_MODE);
202 if (ret < 0) {
203 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
204 __func__, PIXCIR_REG_POWER_MODE, ret);
205 return ret;
206 }
207
208 ret &= ~PIXCIR_POWER_MODE_MASK;
209 ret |= mode;
210
211 /* Always AUTO_IDLE */
212 ret |= PIXCIR_POWER_ALLOW_IDLE;
213
214 ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_POWER_MODE, ret);
215 if (ret < 0) {
216 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
217 __func__, PIXCIR_REG_POWER_MODE, ret);
218 return ret;
219 }
220
221 if (mode == PIXCIR_POWER_HALT) {
222 if (ts->gpio_wake)
223 gpiod_set_value_cansleep(ts->gpio_wake, 0);
224 }
225
226 return 0;
227}
228
229/*
230 * Set the interrupt mode for the device i.e. ATTB line behaviour
231 *
232 * @polarity : 1 for active high, 0 for active low.
233 */
234static int pixcir_set_int_mode(struct pixcir_i2c_ts_data *ts,
235 enum pixcir_int_mode mode, bool polarity)
236{
237 struct device *dev = &ts->client->dev;
238 int ret;
239
240 ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
241 if (ret < 0) {
242 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
243 __func__, PIXCIR_REG_INT_MODE, ret);
244 return ret;
245 }
246
247 ret &= ~PIXCIR_INT_MODE_MASK;
248 ret |= mode;
249
250 if (polarity)
251 ret |= PIXCIR_INT_POL_HIGH;
252 else
253 ret &= ~PIXCIR_INT_POL_HIGH;
254
255 ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
256 if (ret < 0) {
257 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
258 __func__, PIXCIR_REG_INT_MODE, ret);
259 return ret;
260 }
261
262 return 0;
263}
264
265/*
266 * Enable/disable interrupt generation
267 */
268static int pixcir_int_enable(struct pixcir_i2c_ts_data *ts, bool enable)
269{
270 struct device *dev = &ts->client->dev;
271 int ret;
272
273 ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
274 if (ret < 0) {
275 dev_err(dev, "%s: can't read reg 0x%x : %d\n",
276 __func__, PIXCIR_REG_INT_MODE, ret);
277 return ret;
278 }
279
280 if (enable)
281 ret |= PIXCIR_INT_ENABLE;
282 else
283 ret &= ~PIXCIR_INT_ENABLE;
284
285 ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
286 if (ret < 0) {
287 dev_err(dev, "%s: can't write reg 0x%x : %d\n",
288 __func__, PIXCIR_REG_INT_MODE, ret);
289 return ret;
290 }
291
292 return 0;
293}
294
295static int pixcir_start(struct pixcir_i2c_ts_data *ts)
296{
297 struct device *dev = &ts->client->dev;
298 int error;
299
300 if (ts->gpio_enable) {
301 gpiod_set_value_cansleep(ts->gpio_enable, 1);
302 msleep(100);
303 }
304
305 /* LEVEL_TOUCH interrupt with active low polarity */
306 error = pixcir_set_int_mode(ts, PIXCIR_INT_LEVEL_TOUCH, 0);
307 if (error) {
308 dev_err(dev, "Failed to set interrupt mode: %d\n", error);
309 return error;
310 }
311
312 ts->running = true;
313 mb(); /* Update status before IRQ can fire */
314
315 /* enable interrupt generation */
316 error = pixcir_int_enable(ts, true);
317 if (error) {
318 dev_err(dev, "Failed to enable interrupt generation: %d\n",
319 error);
320 return error;
321 }
322
323 return 0;
324}
325
326static int pixcir_stop(struct pixcir_i2c_ts_data *ts)
327{
328 int error;
329
330 /* Disable interrupt generation */
331 error = pixcir_int_enable(ts, false);
332 if (error) {
333 dev_err(&ts->client->dev,
334 "Failed to disable interrupt generation: %d\n",
335 error);
336 return error;
337 }
338
339 /* Exit ISR if running, no more report parsing */
340 ts->running = false;
341 mb(); /* update status before we synchronize irq */
342
343 /* Wait till running ISR is complete */
344 synchronize_irq(ts->client->irq);
345
346 if (ts->gpio_enable)
347 gpiod_set_value_cansleep(ts->gpio_enable, 0);
348
349 return 0;
350}
351
352static int pixcir_input_open(struct input_dev *dev)
353{
354 struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
355
356 return pixcir_start(ts);
357}
358
359static void pixcir_input_close(struct input_dev *dev)
360{
361 struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
362
363 pixcir_stop(ts);
364}
365
366static int __maybe_unused pixcir_i2c_ts_suspend(struct device *dev)
367{
368 struct i2c_client *client = to_i2c_client(dev);
369 struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
370 struct input_dev *input = ts->input;
371 int ret = 0;
372
373 mutex_lock(&input->mutex);
374
375 if (device_may_wakeup(&client->dev)) {
376 if (!input->users) {
377 ret = pixcir_start(ts);
378 if (ret) {
379 dev_err(dev, "Failed to start\n");
380 goto unlock;
381 }
382 }
383 } else if (input->users) {
384 ret = pixcir_stop(ts);
385 }
386
387unlock:
388 mutex_unlock(&input->mutex);
389
390 return ret;
391}
392
393static int __maybe_unused pixcir_i2c_ts_resume(struct device *dev)
394{
395 struct i2c_client *client = to_i2c_client(dev);
396 struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
397 struct input_dev *input = ts->input;
398 int ret = 0;
399
400 mutex_lock(&input->mutex);
401
402 if (device_may_wakeup(&client->dev)) {
403 if (!input->users) {
404 ret = pixcir_stop(ts);
405 if (ret) {
406 dev_err(dev, "Failed to stop\n");
407 goto unlock;
408 }
409 }
410 } else if (input->users) {
411 ret = pixcir_start(ts);
412 }
413
414unlock:
415 mutex_unlock(&input->mutex);
416
417 return ret;
418}
419
420static SIMPLE_DEV_PM_OPS(pixcir_dev_pm_ops,
421 pixcir_i2c_ts_suspend, pixcir_i2c_ts_resume);
422
423#ifdef CONFIG_OF
424static const struct of_device_id pixcir_of_match[];
425
426static int pixcir_parse_dt(struct device *dev,
427 struct pixcir_i2c_ts_data *tsdata)
428{
429 tsdata->chip = of_device_get_match_data(dev);
430 if (!tsdata->chip)
431 return -EINVAL;
432
433 return 0;
434}
435#else
436static int pixcir_parse_dt(struct device *dev,
437 struct pixcir_i2c_ts_data *tsdata)
438{
439 return -EINVAL;
440}
441#endif
442
443static int pixcir_i2c_ts_probe(struct i2c_client *client,
444 const struct i2c_device_id *id)
445{
446 const struct pixcir_ts_platform_data *pdata =
447 dev_get_platdata(&client->dev);
448 struct device *dev = &client->dev;
449 struct pixcir_i2c_ts_data *tsdata;
450 struct input_dev *input;
451 int error;
452
453 tsdata = devm_kzalloc(dev, sizeof(*tsdata), GFP_KERNEL);
454 if (!tsdata)
455 return -ENOMEM;
456
457 if (pdata) {
458 tsdata->chip = &pdata->chip;
459 } else if (dev->of_node) {
460 error = pixcir_parse_dt(dev, tsdata);
461 if (error)
462 return error;
463 } else {
464 dev_err(dev, "platform data not defined\n");
465 return -EINVAL;
466 }
467
468 if (!tsdata->chip->max_fingers) {
469 dev_err(dev, "Invalid max_fingers in chip data\n");
470 return -EINVAL;
471 }
472
473 input = devm_input_allocate_device(dev);
474 if (!input) {
475 dev_err(dev, "Failed to allocate input device\n");
476 return -ENOMEM;
477 }
478
479 tsdata->client = client;
480 tsdata->input = input;
481
482 input->name = client->name;
483 input->id.bustype = BUS_I2C;
484 input->open = pixcir_input_open;
485 input->close = pixcir_input_close;
486 input->dev.parent = dev;
487
488 if (pdata) {
489 input_set_abs_params(input, ABS_MT_POSITION_X, 0, pdata->x_max, 0, 0);
490 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, pdata->y_max, 0, 0);
491 } else {
492 input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
493 input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
494 touchscreen_parse_properties(input, true, &tsdata->prop);
495 if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
496 !input_abs_get_max(input, ABS_MT_POSITION_Y)) {
497 dev_err(dev, "Touchscreen size is not specified\n");
498 return -EINVAL;
499 }
500 }
501
502 tsdata->max_fingers = tsdata->chip->max_fingers;
503 if (tsdata->max_fingers > PIXCIR_MAX_SLOTS) {
504 tsdata->max_fingers = PIXCIR_MAX_SLOTS;
505 dev_info(dev, "Limiting maximum fingers to %d\n",
506 tsdata->max_fingers);
507 }
508
509 error = input_mt_init_slots(input, tsdata->max_fingers,
510 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
511 if (error) {
512 dev_err(dev, "Error initializing Multi-Touch slots\n");
513 return error;
514 }
515
516 input_set_drvdata(input, tsdata);
517
518 tsdata->gpio_attb = devm_gpiod_get(dev, "attb", GPIOD_IN);
519 if (IS_ERR(tsdata->gpio_attb)) {
520 error = PTR_ERR(tsdata->gpio_attb);
521 dev_err(dev, "Failed to request ATTB gpio: %d\n", error);
522 return error;
523 }
524
525 tsdata->gpio_reset = devm_gpiod_get_optional(dev, "reset",
526 GPIOD_OUT_LOW);
527 if (IS_ERR(tsdata->gpio_reset)) {
528 error = PTR_ERR(tsdata->gpio_reset);
529 dev_err(dev, "Failed to request RESET gpio: %d\n", error);
530 return error;
531 }
532
533 tsdata->gpio_wake = devm_gpiod_get_optional(dev, "wake",
534 GPIOD_OUT_HIGH);
535 if (IS_ERR(tsdata->gpio_wake)) {
536 error = PTR_ERR(tsdata->gpio_wake);
537 if (error != -EPROBE_DEFER)
538 dev_err(dev, "Failed to get wake gpio: %d\n", error);
539 return error;
540 }
541
542 tsdata->gpio_enable = devm_gpiod_get_optional(dev, "enable",
543 GPIOD_OUT_HIGH);
544 if (IS_ERR(tsdata->gpio_enable)) {
545 error = PTR_ERR(tsdata->gpio_enable);
546 if (error != -EPROBE_DEFER)
547 dev_err(dev, "Failed to get enable gpio: %d\n", error);
548 return error;
549 }
550
551 if (tsdata->gpio_enable)
552 msleep(100);
553
554 error = devm_request_threaded_irq(dev, client->irq, NULL, pixcir_ts_isr,
555 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
556 client->name, tsdata);
557 if (error) {
558 dev_err(dev, "failed to request irq %d\n", client->irq);
559 return error;
560 }
561
562 pixcir_reset(tsdata);
563
564 /* Always be in IDLE mode to save power, device supports auto wake */
565 error = pixcir_set_power_mode(tsdata, PIXCIR_POWER_IDLE);
566 if (error) {
567 dev_err(dev, "Failed to set IDLE mode\n");
568 return error;
569 }
570
571 /* Stop device till opened */
572 error = pixcir_stop(tsdata);
573 if (error)
574 return error;
575
576 error = input_register_device(input);
577 if (error)
578 return error;
579
580 i2c_set_clientdata(client, tsdata);
581
582 return 0;
583}
584
585static const struct i2c_device_id pixcir_i2c_ts_id[] = {
586 { "pixcir_ts", 0 },
587 { "pixcir_tangoc", 0 },
588 { }
589};
590MODULE_DEVICE_TABLE(i2c, pixcir_i2c_ts_id);
591
592#ifdef CONFIG_OF
593static const struct pixcir_i2c_chip_data pixcir_ts_data = {
594 .max_fingers = 2,
595 /* no hw id support */
596};
597
598static const struct pixcir_i2c_chip_data pixcir_tangoc_data = {
599 .max_fingers = 5,
600 .has_hw_ids = true,
601};
602
603static const struct of_device_id pixcir_of_match[] = {
604 { .compatible = "pixcir,pixcir_ts", .data = &pixcir_ts_data },
605 { .compatible = "pixcir,pixcir_tangoc", .data = &pixcir_tangoc_data },
606 { }
607};
608MODULE_DEVICE_TABLE(of, pixcir_of_match);
609#endif
610
611static struct i2c_driver pixcir_i2c_ts_driver = {
612 .driver = {
613 .name = "pixcir_ts",
614 .pm = &pixcir_dev_pm_ops,
615 .of_match_table = of_match_ptr(pixcir_of_match),
616 },
617 .probe = pixcir_i2c_ts_probe,
618 .id_table = pixcir_i2c_ts_id,
619};
620
621module_i2c_driver(pixcir_i2c_ts_driver);
622
623MODULE_AUTHOR("Jianchun Bian <jcbian@pixcir.com.cn>, Dequan Meng <dqmeng@pixcir.com.cn>");
624MODULE_DESCRIPTION("Pixcir I2C Touchscreen Driver");
625MODULE_LICENSE("GPL");
626