1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Core Source for:
4  * Cypress TrueTouch(TM) Standard Product (TTSP) touchscreen drivers.
5  * For use with Cypress Txx3xx parts.
6  * Supported parts include:
7  * CY8CTST341
8  * CY8CTMA340
9  *
10  * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
11  * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
12  *
13  * Contact Cypress Semiconductor at www.cypress.com <kev@cypress.com>
14  */
15 
16 #include <linux/delay.h>
17 #include <linux/input.h>
18 #include <linux/input/mt.h>
19 #include <linux/input/touchscreen.h>
20 #include <linux/gpio.h>
21 #include <linux/interrupt.h>
22 #include <linux/slab.h>
23 #include <linux/property.h>
24 #include <linux/gpio/consumer.h>
25 
26 #include "cyttsp_core.h"
27 
28 /* Bootloader number of command keys */
29 #define CY_NUM_BL_KEYS		8
30 
31 /* helpers */
32 #define GET_NUM_TOUCHES(x)		((x) & 0x0F)
33 #define IS_LARGE_AREA(x)		(((x) & 0x10) >> 4)
34 #define IS_BAD_PKT(x)			((x) & 0x20)
35 #define IS_VALID_APP(x)			((x) & 0x01)
36 #define IS_OPERATIONAL_ERR(x)		((x) & 0x3F)
37 #define GET_HSTMODE(reg)		(((reg) & 0x70) >> 4)
38 #define GET_BOOTLOADERMODE(reg)		(((reg) & 0x10) >> 4)
39 
40 #define CY_REG_BASE			0x00
41 #define CY_REG_ACT_DIST			0x1E
42 #define CY_REG_ACT_INTRVL		0x1D
43 #define CY_REG_TCH_TMOUT		(CY_REG_ACT_INTRVL + 1)
44 #define CY_REG_LP_INTRVL		(CY_REG_TCH_TMOUT + 1)
45 #define CY_MAXZ				255
46 #define CY_DELAY_DFLT			20 /* ms */
47 #define CY_DELAY_MAX			500
48 #define CY_ACT_DIST_DFLT		0xF8
49 #define CY_ACT_DIST_MASK		0x0F
50 #define CY_HNDSHK_BIT			0x80
51 /* device mode bits */
52 #define CY_OPERATE_MODE			0x00
53 #define CY_SYSINFO_MODE			0x10
54 /* power mode select bits */
55 #define CY_SOFT_RESET_MODE		0x01 /* return to Bootloader mode */
56 #define CY_DEEP_SLEEP_MODE		0x02
57 #define CY_LOW_POWER_MODE		0x04
58 
59 /* Slots management */
60 #define CY_MAX_FINGER			4
61 #define CY_MAX_ID			16
62 
63 static const u8 bl_command[] = {
64 	0x00,			/* file offset */
65 	0xFF,			/* command */
66 	0xA5,			/* exit bootloader command */
67 	0, 1, 2, 3, 4, 5, 6, 7	/* default keys */
68 };
69 
70 static int ttsp_read_block_data(struct cyttsp *ts, u8 command,
71 				u8 length, void *buf)
72 {
73 	int error;
74 	int tries;
75 
76 	for (tries = 0; tries < CY_NUM_RETRY; tries++) {
77 		error = ts->bus_ops->read(ts->dev, ts->xfer_buf, command,
78 				length, buf);
79 		if (!error)
80 			return 0;
81 
82 		msleep(CY_DELAY_DFLT);
83 	}
84 
85 	return -EIO;
86 }
87 
88 static int ttsp_write_block_data(struct cyttsp *ts, u8 command,
89 				 u8 length, void *buf)
90 {
91 	int error;
92 	int tries;
93 
94 	for (tries = 0; tries < CY_NUM_RETRY; tries++) {
95 		error = ts->bus_ops->write(ts->dev, ts->xfer_buf, command,
96 				length, buf);
97 		if (!error)
98 			return 0;
99 
100 		msleep(CY_DELAY_DFLT);
101 	}
102 
103 	return -EIO;
104 }
105 
106 static int ttsp_send_command(struct cyttsp *ts, u8 cmd)
107 {
108 	return ttsp_write_block_data(ts, CY_REG_BASE, sizeof(cmd), &cmd);
109 }
110 
111 static int cyttsp_handshake(struct cyttsp *ts)
112 {
113 	if (ts->use_hndshk)
114 		return ttsp_send_command(ts,
115 				ts->xy_data.hst_mode ^ CY_HNDSHK_BIT);
116 
117 	return 0;
118 }
119 
120 static int cyttsp_load_bl_regs(struct cyttsp *ts)
121 {
122 	memset(&ts->bl_data, 0, sizeof(ts->bl_data));
123 	ts->bl_data.bl_status = 0x10;
124 
125 	return ttsp_read_block_data(ts, CY_REG_BASE,
126 				    sizeof(ts->bl_data), &ts->bl_data);
127 }
128 
129 static int cyttsp_exit_bl_mode(struct cyttsp *ts)
130 {
131 	int error;
132 	u8 bl_cmd[sizeof(bl_command)];
133 
134 	memcpy(bl_cmd, bl_command, sizeof(bl_command));
135 	if (ts->bl_keys)
136 		memcpy(&bl_cmd[sizeof(bl_command) - CY_NUM_BL_KEYS],
137 			ts->bl_keys, CY_NUM_BL_KEYS);
138 
139 	error = ttsp_write_block_data(ts, CY_REG_BASE,
140 				      sizeof(bl_cmd), bl_cmd);
141 	if (error)
142 		return error;
143 
144 	/* wait for TTSP Device to complete the operation */
145 	msleep(CY_DELAY_DFLT);
146 
147 	error = cyttsp_load_bl_regs(ts);
148 	if (error)
149 		return error;
150 
151 	if (GET_BOOTLOADERMODE(ts->bl_data.bl_status))
152 		return -EIO;
153 
154 	return 0;
155 }
156 
157 static int cyttsp_set_operational_mode(struct cyttsp *ts)
158 {
159 	int error;
160 
161 	error = ttsp_send_command(ts, CY_OPERATE_MODE);
162 	if (error)
163 		return error;
164 
165 	/* wait for TTSP Device to complete switch to Operational mode */
166 	error = ttsp_read_block_data(ts, CY_REG_BASE,
167 				     sizeof(ts->xy_data), &ts->xy_data);
168 	if (error)
169 		return error;
170 
171 	error = cyttsp_handshake(ts);
172 	if (error)
173 		return error;
174 
175 	return ts->xy_data.act_dist == CY_ACT_DIST_DFLT ? -EIO : 0;
176 }
177 
178 static int cyttsp_set_sysinfo_mode(struct cyttsp *ts)
179 {
180 	int error;
181 
182 	memset(&ts->sysinfo_data, 0, sizeof(ts->sysinfo_data));
183 
184 	/* switch to sysinfo mode */
185 	error = ttsp_send_command(ts, CY_SYSINFO_MODE);
186 	if (error)
187 		return error;
188 
189 	/* read sysinfo registers */
190 	msleep(CY_DELAY_DFLT);
191 	error = ttsp_read_block_data(ts, CY_REG_BASE, sizeof(ts->sysinfo_data),
192 				      &ts->sysinfo_data);
193 	if (error)
194 		return error;
195 
196 	error = cyttsp_handshake(ts);
197 	if (error)
198 		return error;
199 
200 	if (!ts->sysinfo_data.tts_verh && !ts->sysinfo_data.tts_verl)
201 		return -EIO;
202 
203 	return 0;
204 }
205 
206 static int cyttsp_set_sysinfo_regs(struct cyttsp *ts)
207 {
208 	int retval = 0;
209 
210 	if (ts->act_intrvl != CY_ACT_INTRVL_DFLT ||
211 	    ts->tch_tmout != CY_TCH_TMOUT_DFLT ||
212 	    ts->lp_intrvl != CY_LP_INTRVL_DFLT) {
213 
214 		u8 intrvl_ray[] = {
215 			ts->act_intrvl,
216 			ts->tch_tmout,
217 			ts->lp_intrvl
218 		};
219 
220 		/* set intrvl registers */
221 		retval = ttsp_write_block_data(ts, CY_REG_ACT_INTRVL,
222 					sizeof(intrvl_ray), intrvl_ray);
223 		msleep(CY_DELAY_DFLT);
224 	}
225 
226 	return retval;
227 }
228 
229 static void cyttsp_hard_reset(struct cyttsp *ts)
230 {
231 	if (ts->reset_gpio) {
232 		gpiod_set_value_cansleep(ts->reset_gpio, 1);
233 		msleep(CY_DELAY_DFLT);
234 		gpiod_set_value_cansleep(ts->reset_gpio, 0);
235 		msleep(CY_DELAY_DFLT);
236 	}
237 }
238 
239 static int cyttsp_soft_reset(struct cyttsp *ts)
240 {
241 	unsigned long timeout;
242 	int retval;
243 
244 	/* wait for interrupt to set ready completion */
245 	reinit_completion(&ts->bl_ready);
246 	ts->state = CY_BL_STATE;
247 
248 	enable_irq(ts->irq);
249 
250 	retval = ttsp_send_command(ts, CY_SOFT_RESET_MODE);
251 	if (retval)
252 		goto out;
253 
254 	timeout = wait_for_completion_timeout(&ts->bl_ready,
255 			msecs_to_jiffies(CY_DELAY_DFLT * CY_DELAY_MAX));
256 	retval = timeout ? 0 : -EIO;
257 
258 out:
259 	ts->state = CY_IDLE_STATE;
260 	disable_irq(ts->irq);
261 	return retval;
262 }
263 
264 static int cyttsp_act_dist_setup(struct cyttsp *ts)
265 {
266 	u8 act_dist_setup = ts->act_dist;
267 
268 	/* Init gesture; active distance setup */
269 	return ttsp_write_block_data(ts, CY_REG_ACT_DIST,
270 				sizeof(act_dist_setup), &act_dist_setup);
271 }
272 
273 static void cyttsp_extract_track_ids(struct cyttsp_xydata *xy_data, int *ids)
274 {
275 	ids[0] = xy_data->touch12_id >> 4;
276 	ids[1] = xy_data->touch12_id & 0xF;
277 	ids[2] = xy_data->touch34_id >> 4;
278 	ids[3] = xy_data->touch34_id & 0xF;
279 }
280 
281 static const struct cyttsp_tch *cyttsp_get_tch(struct cyttsp_xydata *xy_data,
282 					       int idx)
283 {
284 	switch (idx) {
285 	case 0:
286 		return &xy_data->tch1;
287 	case 1:
288 		return &xy_data->tch2;
289 	case 2:
290 		return &xy_data->tch3;
291 	case 3:
292 		return &xy_data->tch4;
293 	default:
294 		return NULL;
295 	}
296 }
297 
298 static void cyttsp_report_tchdata(struct cyttsp *ts)
299 {
300 	struct cyttsp_xydata *xy_data = &ts->xy_data;
301 	struct input_dev *input = ts->input;
302 	int num_tch = GET_NUM_TOUCHES(xy_data->tt_stat);
303 	const struct cyttsp_tch *tch;
304 	int ids[CY_MAX_ID];
305 	int i;
306 	DECLARE_BITMAP(used, CY_MAX_ID);
307 
308 	if (IS_LARGE_AREA(xy_data->tt_stat) == 1) {
309 		/* terminate all active tracks */
310 		num_tch = 0;
311 		dev_dbg(ts->dev, "%s: Large area detected\n", __func__);
312 	} else if (num_tch > CY_MAX_FINGER) {
313 		/* terminate all active tracks */
314 		num_tch = 0;
315 		dev_dbg(ts->dev, "%s: Num touch error detected\n", __func__);
316 	} else if (IS_BAD_PKT(xy_data->tt_mode)) {
317 		/* terminate all active tracks */
318 		num_tch = 0;
319 		dev_dbg(ts->dev, "%s: Invalid buffer detected\n", __func__);
320 	}
321 
322 	cyttsp_extract_track_ids(xy_data, ids);
323 
324 	bitmap_zero(used, CY_MAX_ID);
325 
326 	for (i = 0; i < num_tch; i++) {
327 		tch = cyttsp_get_tch(xy_data, i);
328 
329 		input_mt_slot(input, ids[i]);
330 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
331 		input_report_abs(input, ABS_MT_POSITION_X, be16_to_cpu(tch->x));
332 		input_report_abs(input, ABS_MT_POSITION_Y, be16_to_cpu(tch->y));
333 		input_report_abs(input, ABS_MT_TOUCH_MAJOR, tch->z);
334 
335 		__set_bit(ids[i], used);
336 	}
337 
338 	for (i = 0; i < CY_MAX_ID; i++) {
339 		if (test_bit(i, used))
340 			continue;
341 
342 		input_mt_slot(input, i);
343 		input_mt_report_slot_inactive(input);
344 	}
345 
346 	input_sync(input);
347 }
348 
349 static irqreturn_t cyttsp_irq(int irq, void *handle)
350 {
351 	struct cyttsp *ts = handle;
352 	int error;
353 
354 	if (unlikely(ts->state == CY_BL_STATE)) {
355 		complete(&ts->bl_ready);
356 		goto out;
357 	}
358 
359 	/* Get touch data from CYTTSP device */
360 	error = ttsp_read_block_data(ts, CY_REG_BASE,
361 				 sizeof(struct cyttsp_xydata), &ts->xy_data);
362 	if (error)
363 		goto out;
364 
365 	/* provide flow control handshake */
366 	error = cyttsp_handshake(ts);
367 	if (error)
368 		goto out;
369 
370 	if (unlikely(ts->state == CY_IDLE_STATE))
371 		goto out;
372 
373 	if (GET_BOOTLOADERMODE(ts->xy_data.tt_mode)) {
374 		/*
375 		 * TTSP device has reset back to bootloader mode.
376 		 * Restore to operational mode.
377 		 */
378 		error = cyttsp_exit_bl_mode(ts);
379 		if (error) {
380 			dev_err(ts->dev,
381 				"Could not return to operational mode, err: %d\n",
382 				error);
383 			ts->state = CY_IDLE_STATE;
384 		}
385 	} else {
386 		cyttsp_report_tchdata(ts);
387 	}
388 
389 out:
390 	return IRQ_HANDLED;
391 }
392 
393 static int cyttsp_power_on(struct cyttsp *ts)
394 {
395 	int error;
396 
397 	error = cyttsp_soft_reset(ts);
398 	if (error)
399 		return error;
400 
401 	error = cyttsp_load_bl_regs(ts);
402 	if (error)
403 		return error;
404 
405 	if (GET_BOOTLOADERMODE(ts->bl_data.bl_status) &&
406 	    IS_VALID_APP(ts->bl_data.bl_status)) {
407 		error = cyttsp_exit_bl_mode(ts);
408 		if (error)
409 			return error;
410 	}
411 
412 	if (GET_HSTMODE(ts->bl_data.bl_file) != CY_OPERATE_MODE ||
413 	    IS_OPERATIONAL_ERR(ts->bl_data.bl_status)) {
414 		return -ENODEV;
415 	}
416 
417 	error = cyttsp_set_sysinfo_mode(ts);
418 	if (error)
419 		return error;
420 
421 	error = cyttsp_set_sysinfo_regs(ts);
422 	if (error)
423 		return error;
424 
425 	error = cyttsp_set_operational_mode(ts);
426 	if (error)
427 		return error;
428 
429 	/* init active distance */
430 	error = cyttsp_act_dist_setup(ts);
431 	if (error)
432 		return error;
433 
434 	ts->state = CY_ACTIVE_STATE;
435 
436 	return 0;
437 }
438 
439 static int cyttsp_enable(struct cyttsp *ts)
440 {
441 	int error;
442 
443 	/*
444 	 * The device firmware can wake on an I2C or SPI memory slave
445 	 * address match. So just reading a register is sufficient to
446 	 * wake up the device. The first read attempt will fail but it
447 	 * will wake it up making the second read attempt successful.
448 	 */
449 	error = ttsp_read_block_data(ts, CY_REG_BASE,
450 				     sizeof(ts->xy_data), &ts->xy_data);
451 	if (error)
452 		return error;
453 
454 	if (GET_HSTMODE(ts->xy_data.hst_mode))
455 		return -EIO;
456 
457 	enable_irq(ts->irq);
458 
459 	return 0;
460 }
461 
462 static int cyttsp_disable(struct cyttsp *ts)
463 {
464 	int error;
465 
466 	error = ttsp_send_command(ts, CY_LOW_POWER_MODE);
467 	if (error)
468 		return error;
469 
470 	disable_irq(ts->irq);
471 
472 	return 0;
473 }
474 
475 static int __maybe_unused cyttsp_suspend(struct device *dev)
476 {
477 	struct cyttsp *ts = dev_get_drvdata(dev);
478 	int retval = 0;
479 
480 	mutex_lock(&ts->input->mutex);
481 
482 	if (ts->input->users) {
483 		retval = cyttsp_disable(ts);
484 		if (retval == 0)
485 			ts->suspended = true;
486 	}
487 
488 	mutex_unlock(&ts->input->mutex);
489 
490 	return retval;
491 }
492 
493 static int __maybe_unused cyttsp_resume(struct device *dev)
494 {
495 	struct cyttsp *ts = dev_get_drvdata(dev);
496 
497 	mutex_lock(&ts->input->mutex);
498 
499 	if (ts->input->users)
500 		cyttsp_enable(ts);
501 
502 	ts->suspended = false;
503 
504 	mutex_unlock(&ts->input->mutex);
505 
506 	return 0;
507 }
508 
509 SIMPLE_DEV_PM_OPS(cyttsp_pm_ops, cyttsp_suspend, cyttsp_resume);
510 EXPORT_SYMBOL_GPL(cyttsp_pm_ops);
511 
512 static int cyttsp_open(struct input_dev *dev)
513 {
514 	struct cyttsp *ts = input_get_drvdata(dev);
515 	int retval = 0;
516 
517 	if (!ts->suspended)
518 		retval = cyttsp_enable(ts);
519 
520 	return retval;
521 }
522 
523 static void cyttsp_close(struct input_dev *dev)
524 {
525 	struct cyttsp *ts = input_get_drvdata(dev);
526 
527 	if (!ts->suspended)
528 		cyttsp_disable(ts);
529 }
530 
531 static int cyttsp_parse_properties(struct cyttsp *ts)
532 {
533 	struct device *dev = ts->dev;
534 	u32 dt_value;
535 	int ret;
536 
537 	ts->bl_keys = devm_kzalloc(dev, CY_NUM_BL_KEYS, GFP_KERNEL);
538 	if (!ts->bl_keys)
539 		return -ENOMEM;
540 
541 	/* Set some default values */
542 	ts->use_hndshk = false;
543 	ts->act_dist = CY_ACT_DIST_DFLT;
544 	ts->act_intrvl = CY_ACT_INTRVL_DFLT;
545 	ts->tch_tmout = CY_TCH_TMOUT_DFLT;
546 	ts->lp_intrvl = CY_LP_INTRVL_DFLT;
547 
548 	ret = device_property_read_u8_array(dev, "bootloader-key",
549 					    ts->bl_keys, CY_NUM_BL_KEYS);
550 	if (ret) {
551 		dev_err(dev,
552 			"bootloader-key property could not be retrieved\n");
553 		return ret;
554 	}
555 
556 	ts->use_hndshk = device_property_present(dev, "use-handshake");
557 
558 	if (!device_property_read_u32(dev, "active-distance", &dt_value)) {
559 		if (dt_value > 15) {
560 			dev_err(dev, "active-distance (%u) must be [0-15]\n",
561 				dt_value);
562 			return -EINVAL;
563 		}
564 		ts->act_dist &= ~CY_ACT_DIST_MASK;
565 		ts->act_dist |= dt_value;
566 	}
567 
568 	if (!device_property_read_u32(dev, "active-interval-ms", &dt_value)) {
569 		if (dt_value > 255) {
570 			dev_err(dev, "active-interval-ms (%u) must be [0-255]\n",
571 				dt_value);
572 			return -EINVAL;
573 		}
574 		ts->act_intrvl = dt_value;
575 	}
576 
577 	if (!device_property_read_u32(dev, "lowpower-interval-ms", &dt_value)) {
578 		if (dt_value > 2550) {
579 			dev_err(dev, "lowpower-interval-ms (%u) must be [0-2550]\n",
580 				dt_value);
581 			return -EINVAL;
582 		}
583 		/* Register value is expressed in 0.01s / bit */
584 		ts->lp_intrvl = dt_value / 10;
585 	}
586 
587 	if (!device_property_read_u32(dev, "touch-timeout-ms", &dt_value)) {
588 		if (dt_value > 2550) {
589 			dev_err(dev, "touch-timeout-ms (%u) must be [0-2550]\n",
590 				dt_value);
591 			return -EINVAL;
592 		}
593 		/* Register value is expressed in 0.01s / bit */
594 		ts->tch_tmout = dt_value / 10;
595 	}
596 
597 	return 0;
598 }
599 
600 struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
601 			    struct device *dev, int irq, size_t xfer_buf_size)
602 {
603 	struct cyttsp *ts;
604 	struct input_dev *input_dev;
605 	int error;
606 
607 	ts = devm_kzalloc(dev, sizeof(*ts) + xfer_buf_size, GFP_KERNEL);
608 	if (!ts)
609 		return ERR_PTR(-ENOMEM);
610 
611 	input_dev = devm_input_allocate_device(dev);
612 	if (!input_dev)
613 		return ERR_PTR(-ENOMEM);
614 
615 	ts->dev = dev;
616 	ts->input = input_dev;
617 	ts->bus_ops = bus_ops;
618 	ts->irq = irq;
619 
620 	ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
621 	if (IS_ERR(ts->reset_gpio)) {
622 		error = PTR_ERR(ts->reset_gpio);
623 		dev_err(dev, "Failed to request reset gpio, error %d\n", error);
624 		return ERR_PTR(error);
625 	}
626 
627 	error = cyttsp_parse_properties(ts);
628 	if (error)
629 		return ERR_PTR(error);
630 
631 	init_completion(&ts->bl_ready);
632 	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
633 
634 	input_dev->name = "Cypress TTSP TouchScreen";
635 	input_dev->phys = ts->phys;
636 	input_dev->id.bustype = bus_ops->bustype;
637 	input_dev->dev.parent = ts->dev;
638 
639 	input_dev->open = cyttsp_open;
640 	input_dev->close = cyttsp_close;
641 
642 	input_set_drvdata(input_dev, ts);
643 
644 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
645 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
646 	touchscreen_parse_properties(input_dev, true, NULL);
647 
648 	error = input_mt_init_slots(input_dev, CY_MAX_ID, 0);
649 	if (error) {
650 		dev_err(dev, "Unable to init MT slots.\n");
651 		return ERR_PTR(error);
652 	}
653 
654 	error = devm_request_threaded_irq(dev, ts->irq, NULL, cyttsp_irq,
655 					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
656 					  "cyttsp", ts);
657 	if (error) {
658 		dev_err(ts->dev, "failed to request IRQ %d, err: %d\n",
659 			ts->irq, error);
660 		return ERR_PTR(error);
661 	}
662 
663 	disable_irq(ts->irq);
664 
665 	cyttsp_hard_reset(ts);
666 
667 	error = cyttsp_power_on(ts);
668 	if (error)
669 		return ERR_PTR(error);
670 
671 	error = input_register_device(input_dev);
672 	if (error) {
673 		dev_err(ts->dev, "failed to register input device: %d\n",
674 			error);
675 		return ERR_PTR(error);
676 	}
677 
678 	return ts;
679 }
680 EXPORT_SYMBOL_GPL(cyttsp_probe);
681 
682 MODULE_LICENSE("GPL");
683 MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard touchscreen driver core");
684 MODULE_AUTHOR("Cypress");
685