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 	int retval;
242 
243 	/* wait for interrupt to set ready completion */
244 	reinit_completion(&ts->bl_ready);
245 	ts->state = CY_BL_STATE;
246 
247 	enable_irq(ts->irq);
248 
249 	retval = ttsp_send_command(ts, CY_SOFT_RESET_MODE);
250 	if (retval) {
251 		dev_err(ts->dev, "failed to send soft reset\n");
252 		goto out;
253 	}
254 
255 	if (!wait_for_completion_timeout(&ts->bl_ready,
256 			msecs_to_jiffies(CY_DELAY_DFLT * CY_DELAY_MAX))) {
257 		dev_err(ts->dev, "timeout waiting for soft reset\n");
258 		retval = -EIO;
259 	}
260 
261 out:
262 	ts->state = CY_IDLE_STATE;
263 	disable_irq(ts->irq);
264 	return retval;
265 }
266 
267 static int cyttsp_act_dist_setup(struct cyttsp *ts)
268 {
269 	u8 act_dist_setup = ts->act_dist;
270 
271 	/* Init gesture; active distance setup */
272 	return ttsp_write_block_data(ts, CY_REG_ACT_DIST,
273 				sizeof(act_dist_setup), &act_dist_setup);
274 }
275 
276 static void cyttsp_extract_track_ids(struct cyttsp_xydata *xy_data, int *ids)
277 {
278 	ids[0] = xy_data->touch12_id >> 4;
279 	ids[1] = xy_data->touch12_id & 0xF;
280 	ids[2] = xy_data->touch34_id >> 4;
281 	ids[3] = xy_data->touch34_id & 0xF;
282 }
283 
284 static const struct cyttsp_tch *cyttsp_get_tch(struct cyttsp_xydata *xy_data,
285 					       int idx)
286 {
287 	switch (idx) {
288 	case 0:
289 		return &xy_data->tch1;
290 	case 1:
291 		return &xy_data->tch2;
292 	case 2:
293 		return &xy_data->tch3;
294 	case 3:
295 		return &xy_data->tch4;
296 	default:
297 		return NULL;
298 	}
299 }
300 
301 static void cyttsp_report_tchdata(struct cyttsp *ts)
302 {
303 	struct cyttsp_xydata *xy_data = &ts->xy_data;
304 	struct input_dev *input = ts->input;
305 	int num_tch = GET_NUM_TOUCHES(xy_data->tt_stat);
306 	const struct cyttsp_tch *tch;
307 	int ids[CY_MAX_ID];
308 	int i;
309 	DECLARE_BITMAP(used, CY_MAX_ID);
310 
311 	if (IS_LARGE_AREA(xy_data->tt_stat) == 1) {
312 		/* terminate all active tracks */
313 		num_tch = 0;
314 		dev_dbg(ts->dev, "%s: Large area detected\n", __func__);
315 	} else if (num_tch > CY_MAX_FINGER) {
316 		/* terminate all active tracks */
317 		num_tch = 0;
318 		dev_dbg(ts->dev, "%s: Num touch error detected\n", __func__);
319 	} else if (IS_BAD_PKT(xy_data->tt_mode)) {
320 		/* terminate all active tracks */
321 		num_tch = 0;
322 		dev_dbg(ts->dev, "%s: Invalid buffer detected\n", __func__);
323 	}
324 
325 	cyttsp_extract_track_ids(xy_data, ids);
326 
327 	bitmap_zero(used, CY_MAX_ID);
328 
329 	for (i = 0; i < num_tch; i++) {
330 		tch = cyttsp_get_tch(xy_data, i);
331 
332 		input_mt_slot(input, ids[i]);
333 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
334 		input_report_abs(input, ABS_MT_POSITION_X, be16_to_cpu(tch->x));
335 		input_report_abs(input, ABS_MT_POSITION_Y, be16_to_cpu(tch->y));
336 		input_report_abs(input, ABS_MT_TOUCH_MAJOR, tch->z);
337 
338 		__set_bit(ids[i], used);
339 	}
340 
341 	for (i = 0; i < CY_MAX_ID; i++) {
342 		if (test_bit(i, used))
343 			continue;
344 
345 		input_mt_slot(input, i);
346 		input_mt_report_slot_inactive(input);
347 	}
348 
349 	input_sync(input);
350 }
351 
352 static irqreturn_t cyttsp_irq(int irq, void *handle)
353 {
354 	struct cyttsp *ts = handle;
355 	int error;
356 
357 	if (unlikely(ts->state == CY_BL_STATE)) {
358 		complete(&ts->bl_ready);
359 		goto out;
360 	}
361 
362 	/* Get touch data from CYTTSP device */
363 	error = ttsp_read_block_data(ts, CY_REG_BASE,
364 				 sizeof(struct cyttsp_xydata), &ts->xy_data);
365 	if (error)
366 		goto out;
367 
368 	/* provide flow control handshake */
369 	error = cyttsp_handshake(ts);
370 	if (error)
371 		goto out;
372 
373 	if (unlikely(ts->state == CY_IDLE_STATE))
374 		goto out;
375 
376 	if (GET_BOOTLOADERMODE(ts->xy_data.tt_mode)) {
377 		/*
378 		 * TTSP device has reset back to bootloader mode.
379 		 * Restore to operational mode.
380 		 */
381 		error = cyttsp_exit_bl_mode(ts);
382 		if (error) {
383 			dev_err(ts->dev,
384 				"Could not return to operational mode, err: %d\n",
385 				error);
386 			ts->state = CY_IDLE_STATE;
387 		}
388 	} else {
389 		cyttsp_report_tchdata(ts);
390 	}
391 
392 out:
393 	return IRQ_HANDLED;
394 }
395 
396 static int cyttsp_power_on(struct cyttsp *ts)
397 {
398 	int error;
399 
400 	error = cyttsp_soft_reset(ts);
401 	if (error)
402 		return error;
403 
404 	error = cyttsp_load_bl_regs(ts);
405 	if (error)
406 		return error;
407 
408 	if (GET_BOOTLOADERMODE(ts->bl_data.bl_status) &&
409 	    IS_VALID_APP(ts->bl_data.bl_status)) {
410 		error = cyttsp_exit_bl_mode(ts);
411 		if (error)
412 			return error;
413 	}
414 
415 	if (GET_HSTMODE(ts->bl_data.bl_file) != CY_OPERATE_MODE ||
416 	    IS_OPERATIONAL_ERR(ts->bl_data.bl_status)) {
417 		return -ENODEV;
418 	}
419 
420 	error = cyttsp_set_sysinfo_mode(ts);
421 	if (error)
422 		return error;
423 
424 	error = cyttsp_set_sysinfo_regs(ts);
425 	if (error)
426 		return error;
427 
428 	error = cyttsp_set_operational_mode(ts);
429 	if (error)
430 		return error;
431 
432 	/* init active distance */
433 	error = cyttsp_act_dist_setup(ts);
434 	if (error)
435 		return error;
436 
437 	ts->state = CY_ACTIVE_STATE;
438 
439 	return 0;
440 }
441 
442 static int cyttsp_enable(struct cyttsp *ts)
443 {
444 	int error;
445 
446 	/*
447 	 * The device firmware can wake on an I2C or SPI memory slave
448 	 * address match. So just reading a register is sufficient to
449 	 * wake up the device. The first read attempt will fail but it
450 	 * will wake it up making the second read attempt successful.
451 	 */
452 	error = ttsp_read_block_data(ts, CY_REG_BASE,
453 				     sizeof(ts->xy_data), &ts->xy_data);
454 	if (error)
455 		return error;
456 
457 	if (GET_HSTMODE(ts->xy_data.hst_mode))
458 		return -EIO;
459 
460 	enable_irq(ts->irq);
461 
462 	return 0;
463 }
464 
465 static int cyttsp_disable(struct cyttsp *ts)
466 {
467 	int error;
468 
469 	error = ttsp_send_command(ts, CY_LOW_POWER_MODE);
470 	if (error)
471 		return error;
472 
473 	disable_irq(ts->irq);
474 
475 	return 0;
476 }
477 
478 static int __maybe_unused cyttsp_suspend(struct device *dev)
479 {
480 	struct cyttsp *ts = dev_get_drvdata(dev);
481 	int retval = 0;
482 
483 	mutex_lock(&ts->input->mutex);
484 
485 	if (input_device_enabled(ts->input)) {
486 		retval = cyttsp_disable(ts);
487 		if (retval == 0)
488 			ts->suspended = true;
489 	}
490 
491 	mutex_unlock(&ts->input->mutex);
492 
493 	return retval;
494 }
495 
496 static int __maybe_unused cyttsp_resume(struct device *dev)
497 {
498 	struct cyttsp *ts = dev_get_drvdata(dev);
499 
500 	mutex_lock(&ts->input->mutex);
501 
502 	if (input_device_enabled(ts->input))
503 		cyttsp_enable(ts);
504 
505 	ts->suspended = false;
506 
507 	mutex_unlock(&ts->input->mutex);
508 
509 	return 0;
510 }
511 
512 SIMPLE_DEV_PM_OPS(cyttsp_pm_ops, cyttsp_suspend, cyttsp_resume);
513 EXPORT_SYMBOL_GPL(cyttsp_pm_ops);
514 
515 static int cyttsp_open(struct input_dev *dev)
516 {
517 	struct cyttsp *ts = input_get_drvdata(dev);
518 	int retval = 0;
519 
520 	if (!ts->suspended)
521 		retval = cyttsp_enable(ts);
522 
523 	return retval;
524 }
525 
526 static void cyttsp_close(struct input_dev *dev)
527 {
528 	struct cyttsp *ts = input_get_drvdata(dev);
529 
530 	if (!ts->suspended)
531 		cyttsp_disable(ts);
532 }
533 
534 static int cyttsp_parse_properties(struct cyttsp *ts)
535 {
536 	struct device *dev = ts->dev;
537 	u32 dt_value;
538 	int ret;
539 
540 	ts->bl_keys = devm_kzalloc(dev, CY_NUM_BL_KEYS, GFP_KERNEL);
541 	if (!ts->bl_keys)
542 		return -ENOMEM;
543 
544 	/* Set some default values */
545 	ts->use_hndshk = false;
546 	ts->act_dist = CY_ACT_DIST_DFLT;
547 	ts->act_intrvl = CY_ACT_INTRVL_DFLT;
548 	ts->tch_tmout = CY_TCH_TMOUT_DFLT;
549 	ts->lp_intrvl = CY_LP_INTRVL_DFLT;
550 
551 	ret = device_property_read_u8_array(dev, "bootloader-key",
552 					    ts->bl_keys, CY_NUM_BL_KEYS);
553 	if (ret) {
554 		dev_err(dev,
555 			"bootloader-key property could not be retrieved\n");
556 		return ret;
557 	}
558 
559 	ts->use_hndshk = device_property_present(dev, "use-handshake");
560 
561 	if (!device_property_read_u32(dev, "active-distance", &dt_value)) {
562 		if (dt_value > 15) {
563 			dev_err(dev, "active-distance (%u) must be [0-15]\n",
564 				dt_value);
565 			return -EINVAL;
566 		}
567 		ts->act_dist &= ~CY_ACT_DIST_MASK;
568 		ts->act_dist |= dt_value;
569 	}
570 
571 	if (!device_property_read_u32(dev, "active-interval-ms", &dt_value)) {
572 		if (dt_value > 255) {
573 			dev_err(dev, "active-interval-ms (%u) must be [0-255]\n",
574 				dt_value);
575 			return -EINVAL;
576 		}
577 		ts->act_intrvl = dt_value;
578 	}
579 
580 	if (!device_property_read_u32(dev, "lowpower-interval-ms", &dt_value)) {
581 		if (dt_value > 2550) {
582 			dev_err(dev, "lowpower-interval-ms (%u) must be [0-2550]\n",
583 				dt_value);
584 			return -EINVAL;
585 		}
586 		/* Register value is expressed in 0.01s / bit */
587 		ts->lp_intrvl = dt_value / 10;
588 	}
589 
590 	if (!device_property_read_u32(dev, "touch-timeout-ms", &dt_value)) {
591 		if (dt_value > 2550) {
592 			dev_err(dev, "touch-timeout-ms (%u) must be [0-2550]\n",
593 				dt_value);
594 			return -EINVAL;
595 		}
596 		/* Register value is expressed in 0.01s / bit */
597 		ts->tch_tmout = dt_value / 10;
598 	}
599 
600 	return 0;
601 }
602 
603 struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
604 			    struct device *dev, int irq, size_t xfer_buf_size)
605 {
606 	struct cyttsp *ts;
607 	struct input_dev *input_dev;
608 	int error;
609 
610 	ts = devm_kzalloc(dev, sizeof(*ts) + xfer_buf_size, GFP_KERNEL);
611 	if (!ts)
612 		return ERR_PTR(-ENOMEM);
613 
614 	input_dev = devm_input_allocate_device(dev);
615 	if (!input_dev)
616 		return ERR_PTR(-ENOMEM);
617 
618 	ts->dev = dev;
619 	ts->input = input_dev;
620 	ts->bus_ops = bus_ops;
621 	ts->irq = irq;
622 
623 	ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
624 	if (IS_ERR(ts->reset_gpio)) {
625 		error = PTR_ERR(ts->reset_gpio);
626 		dev_err(dev, "Failed to request reset gpio, error %d\n", error);
627 		return ERR_PTR(error);
628 	}
629 
630 	error = cyttsp_parse_properties(ts);
631 	if (error)
632 		return ERR_PTR(error);
633 
634 	init_completion(&ts->bl_ready);
635 	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
636 
637 	input_dev->name = "Cypress TTSP TouchScreen";
638 	input_dev->phys = ts->phys;
639 	input_dev->id.bustype = bus_ops->bustype;
640 	input_dev->dev.parent = ts->dev;
641 
642 	input_dev->open = cyttsp_open;
643 	input_dev->close = cyttsp_close;
644 
645 	input_set_drvdata(input_dev, ts);
646 
647 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
648 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
649 	touchscreen_parse_properties(input_dev, true, NULL);
650 
651 	error = input_mt_init_slots(input_dev, CY_MAX_ID, 0);
652 	if (error) {
653 		dev_err(dev, "Unable to init MT slots.\n");
654 		return ERR_PTR(error);
655 	}
656 
657 	error = devm_request_threaded_irq(dev, ts->irq, NULL, cyttsp_irq,
658 					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT |
659 					  IRQF_NO_AUTOEN,
660 					  "cyttsp", ts);
661 	if (error) {
662 		dev_err(ts->dev, "failed to request IRQ %d, err: %d\n",
663 			ts->irq, error);
664 		return ERR_PTR(error);
665 	}
666 
667 	cyttsp_hard_reset(ts);
668 
669 	error = cyttsp_power_on(ts);
670 	if (error)
671 		return ERR_PTR(error);
672 
673 	error = input_register_device(input_dev);
674 	if (error) {
675 		dev_err(ts->dev, "failed to register input device: %d\n",
676 			error);
677 		return ERR_PTR(error);
678 	}
679 
680 	return ts;
681 }
682 EXPORT_SYMBOL_GPL(cyttsp_probe);
683 
684 MODULE_LICENSE("GPL");
685 MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard touchscreen driver core");
686 MODULE_AUTHOR("Cypress");
687