1 /*
2  * Core Source for:
3  * Cypress TrueTouch(TM) Standard Product (TTSP) touchscreen drivers.
4  * For use with Cypress Txx3xx parts.
5  * Supported parts include:
6  * CY8CTST341
7  * CY8CTMA340
8  *
9  * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
10  * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License
14  * version 2, and only version 2, as published by the
15  * Free Software Foundation.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License along
23  * with this program; if not, write to the Free Software Foundation, Inc.,
24  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
25  *
26  * Contact Cypress Semiconductor at www.cypress.com <kev@cypress.com>
27  *
28  */
29 
30 #include <linux/delay.h>
31 #include <linux/input.h>
32 #include <linux/input/mt.h>
33 #include <linux/gpio.h>
34 #include <linux/interrupt.h>
35 #include <linux/slab.h>
36 
37 #include "cyttsp_core.h"
38 
39 /* Bootloader number of command keys */
40 #define CY_NUM_BL_KEYS		8
41 
42 /* helpers */
43 #define GET_NUM_TOUCHES(x)		((x) & 0x0F)
44 #define IS_LARGE_AREA(x)		(((x) & 0x10) >> 4)
45 #define IS_BAD_PKT(x)			((x) & 0x20)
46 #define IS_VALID_APP(x)			((x) & 0x01)
47 #define IS_OPERATIONAL_ERR(x)		((x) & 0x3F)
48 #define GET_HSTMODE(reg)		(((reg) & 0x70) >> 4)
49 #define GET_BOOTLOADERMODE(reg)		(((reg) & 0x10) >> 4)
50 
51 #define CY_REG_BASE			0x00
52 #define CY_REG_ACT_DIST			0x1E
53 #define CY_REG_ACT_INTRVL		0x1D
54 #define CY_REG_TCH_TMOUT		(CY_REG_ACT_INTRVL + 1)
55 #define CY_REG_LP_INTRVL		(CY_REG_TCH_TMOUT + 1)
56 #define CY_MAXZ				255
57 #define CY_DELAY_DFLT			20 /* ms */
58 #define CY_DELAY_MAX			500
59 #define CY_ACT_DIST_DFLT		0xF8
60 #define CY_HNDSHK_BIT			0x80
61 /* device mode bits */
62 #define CY_OPERATE_MODE			0x00
63 #define CY_SYSINFO_MODE			0x10
64 /* power mode select bits */
65 #define CY_SOFT_RESET_MODE		0x01 /* return to Bootloader mode */
66 #define CY_DEEP_SLEEP_MODE		0x02
67 #define CY_LOW_POWER_MODE		0x04
68 
69 /* Slots management */
70 #define CY_MAX_FINGER			4
71 #define CY_MAX_ID			16
72 
73 static const u8 bl_command[] = {
74 	0x00,			/* file offset */
75 	0xFF,			/* command */
76 	0xA5,			/* exit bootloader command */
77 	0, 1, 2, 3, 4, 5, 6, 7	/* default keys */
78 };
79 
80 static int ttsp_read_block_data(struct cyttsp *ts, u8 command,
81 				u8 length, void *buf)
82 {
83 	int error;
84 	int tries;
85 
86 	for (tries = 0; tries < CY_NUM_RETRY; tries++) {
87 		error = ts->bus_ops->read(ts->dev, ts->xfer_buf, command,
88 				length, buf);
89 		if (!error)
90 			return 0;
91 
92 		msleep(CY_DELAY_DFLT);
93 	}
94 
95 	return -EIO;
96 }
97 
98 static int ttsp_write_block_data(struct cyttsp *ts, u8 command,
99 				 u8 length, void *buf)
100 {
101 	int error;
102 	int tries;
103 
104 	for (tries = 0; tries < CY_NUM_RETRY; tries++) {
105 		error = ts->bus_ops->write(ts->dev, ts->xfer_buf, command,
106 				length, buf);
107 		if (!error)
108 			return 0;
109 
110 		msleep(CY_DELAY_DFLT);
111 	}
112 
113 	return -EIO;
114 }
115 
116 static int ttsp_send_command(struct cyttsp *ts, u8 cmd)
117 {
118 	return ttsp_write_block_data(ts, CY_REG_BASE, sizeof(cmd), &cmd);
119 }
120 
121 static int cyttsp_load_bl_regs(struct cyttsp *ts)
122 {
123 	memset(&ts->bl_data, 0, sizeof(ts->bl_data));
124 	ts->bl_data.bl_status = 0x10;
125 
126 	return ttsp_read_block_data(ts, CY_REG_BASE,
127 				    sizeof(ts->bl_data), &ts->bl_data);
128 }
129 
130 static int cyttsp_exit_bl_mode(struct cyttsp *ts)
131 {
132 	int error;
133 	u8 bl_cmd[sizeof(bl_command)];
134 
135 	memcpy(bl_cmd, bl_command, sizeof(bl_command));
136 	if (ts->pdata->bl_keys)
137 		memcpy(&bl_cmd[sizeof(bl_command) - CY_NUM_BL_KEYS],
138 			ts->pdata->bl_keys, sizeof(bl_command));
139 
140 	error = ttsp_write_block_data(ts, CY_REG_BASE,
141 				      sizeof(bl_cmd), bl_cmd);
142 	if (error)
143 		return error;
144 
145 	/* wait for TTSP Device to complete the operation */
146 	msleep(CY_DELAY_DFLT);
147 
148 	error = cyttsp_load_bl_regs(ts);
149 	if (error)
150 		return error;
151 
152 	if (GET_BOOTLOADERMODE(ts->bl_data.bl_status))
153 		return -EIO;
154 
155 	return 0;
156 }
157 
158 static int cyttsp_set_operational_mode(struct cyttsp *ts)
159 {
160 	int error;
161 
162 	error = ttsp_send_command(ts, CY_OPERATE_MODE);
163 	if (error)
164 		return error;
165 
166 	/* wait for TTSP Device to complete switch to Operational mode */
167 	error = ttsp_read_block_data(ts, CY_REG_BASE,
168 				     sizeof(ts->xy_data), &ts->xy_data);
169 	if (error)
170 		return error;
171 
172 	return ts->xy_data.act_dist == CY_ACT_DIST_DFLT ? -EIO : 0;
173 }
174 
175 static int cyttsp_set_sysinfo_mode(struct cyttsp *ts)
176 {
177 	int error;
178 
179 	memset(&ts->sysinfo_data, 0, sizeof(ts->sysinfo_data));
180 
181 	/* switch to sysinfo mode */
182 	error = ttsp_send_command(ts, CY_SYSINFO_MODE);
183 	if (error)
184 		return error;
185 
186 	/* read sysinfo registers */
187 	msleep(CY_DELAY_DFLT);
188 	error = ttsp_read_block_data(ts, CY_REG_BASE, sizeof(ts->sysinfo_data),
189 				      &ts->sysinfo_data);
190 	if (error)
191 		return error;
192 
193 	if (!ts->sysinfo_data.tts_verh && !ts->sysinfo_data.tts_verl)
194 		return -EIO;
195 
196 	return 0;
197 }
198 
199 static int cyttsp_set_sysinfo_regs(struct cyttsp *ts)
200 {
201 	int retval = 0;
202 
203 	if (ts->pdata->act_intrvl != CY_ACT_INTRVL_DFLT ||
204 	    ts->pdata->tch_tmout != CY_TCH_TMOUT_DFLT ||
205 	    ts->pdata->lp_intrvl != CY_LP_INTRVL_DFLT) {
206 
207 		u8 intrvl_ray[] = {
208 			ts->pdata->act_intrvl,
209 			ts->pdata->tch_tmout,
210 			ts->pdata->lp_intrvl
211 		};
212 
213 		/* set intrvl registers */
214 		retval = ttsp_write_block_data(ts, CY_REG_ACT_INTRVL,
215 					sizeof(intrvl_ray), intrvl_ray);
216 		msleep(CY_DELAY_DFLT);
217 	}
218 
219 	return retval;
220 }
221 
222 static int cyttsp_soft_reset(struct cyttsp *ts)
223 {
224 	unsigned long timeout;
225 	int retval;
226 
227 	/* wait for interrupt to set ready completion */
228 	INIT_COMPLETION(ts->bl_ready);
229 	ts->state = CY_BL_STATE;
230 
231 	enable_irq(ts->irq);
232 
233 	retval = ttsp_send_command(ts, CY_SOFT_RESET_MODE);
234 	if (retval)
235 		goto out;
236 
237 	timeout = wait_for_completion_timeout(&ts->bl_ready,
238 			msecs_to_jiffies(CY_DELAY_DFLT * CY_DELAY_MAX));
239 	retval = timeout ? 0 : -EIO;
240 
241 out:
242 	ts->state = CY_IDLE_STATE;
243 	disable_irq(ts->irq);
244 	return retval;
245 }
246 
247 static int cyttsp_act_dist_setup(struct cyttsp *ts)
248 {
249 	u8 act_dist_setup = ts->pdata->act_dist;
250 
251 	/* Init gesture; active distance setup */
252 	return ttsp_write_block_data(ts, CY_REG_ACT_DIST,
253 				sizeof(act_dist_setup), &act_dist_setup);
254 }
255 
256 static void cyttsp_extract_track_ids(struct cyttsp_xydata *xy_data, int *ids)
257 {
258 	ids[0] = xy_data->touch12_id >> 4;
259 	ids[1] = xy_data->touch12_id & 0xF;
260 	ids[2] = xy_data->touch34_id >> 4;
261 	ids[3] = xy_data->touch34_id & 0xF;
262 }
263 
264 static const struct cyttsp_tch *cyttsp_get_tch(struct cyttsp_xydata *xy_data,
265 					       int idx)
266 {
267 	switch (idx) {
268 	case 0:
269 		return &xy_data->tch1;
270 	case 1:
271 		return &xy_data->tch2;
272 	case 2:
273 		return &xy_data->tch3;
274 	case 3:
275 		return &xy_data->tch4;
276 	default:
277 		return NULL;
278 	}
279 }
280 
281 static void cyttsp_report_tchdata(struct cyttsp *ts)
282 {
283 	struct cyttsp_xydata *xy_data = &ts->xy_data;
284 	struct input_dev *input = ts->input;
285 	int num_tch = GET_NUM_TOUCHES(xy_data->tt_stat);
286 	const struct cyttsp_tch *tch;
287 	int ids[CY_MAX_ID];
288 	int i;
289 	DECLARE_BITMAP(used, CY_MAX_ID);
290 
291 	if (IS_LARGE_AREA(xy_data->tt_stat) == 1) {
292 		/* terminate all active tracks */
293 		num_tch = 0;
294 		dev_dbg(ts->dev, "%s: Large area detected\n", __func__);
295 	} else if (num_tch > CY_MAX_FINGER) {
296 		/* terminate all active tracks */
297 		num_tch = 0;
298 		dev_dbg(ts->dev, "%s: Num touch error detected\n", __func__);
299 	} else if (IS_BAD_PKT(xy_data->tt_mode)) {
300 		/* terminate all active tracks */
301 		num_tch = 0;
302 		dev_dbg(ts->dev, "%s: Invalid buffer detected\n", __func__);
303 	}
304 
305 	cyttsp_extract_track_ids(xy_data, ids);
306 
307 	bitmap_zero(used, CY_MAX_ID);
308 
309 	for (i = 0; i < num_tch; i++) {
310 		tch = cyttsp_get_tch(xy_data, i);
311 
312 		input_mt_slot(input, ids[i]);
313 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
314 		input_report_abs(input, ABS_MT_POSITION_X, be16_to_cpu(tch->x));
315 		input_report_abs(input, ABS_MT_POSITION_Y, be16_to_cpu(tch->y));
316 		input_report_abs(input, ABS_MT_TOUCH_MAJOR, tch->z);
317 
318 		__set_bit(ids[i], used);
319 	}
320 
321 	for (i = 0; i < CY_MAX_ID; i++) {
322 		if (test_bit(i, used))
323 			continue;
324 
325 		input_mt_slot(input, i);
326 		input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
327 	}
328 
329 	input_sync(input);
330 }
331 
332 static irqreturn_t cyttsp_irq(int irq, void *handle)
333 {
334 	struct cyttsp *ts = handle;
335 	int error;
336 
337 	if (unlikely(ts->state == CY_BL_STATE)) {
338 		complete(&ts->bl_ready);
339 		goto out;
340 	}
341 
342 	/* Get touch data from CYTTSP device */
343 	error = ttsp_read_block_data(ts, CY_REG_BASE,
344 				 sizeof(struct cyttsp_xydata), &ts->xy_data);
345 	if (error)
346 		goto out;
347 
348 	/* provide flow control handshake */
349 	if (ts->pdata->use_hndshk) {
350 		error = ttsp_send_command(ts,
351 				ts->xy_data.hst_mode ^ CY_HNDSHK_BIT);
352 		if (error)
353 			goto out;
354 	}
355 
356 	if (unlikely(ts->state == CY_IDLE_STATE))
357 		goto out;
358 
359 	if (GET_BOOTLOADERMODE(ts->xy_data.tt_mode)) {
360 		/*
361 		 * TTSP device has reset back to bootloader mode.
362 		 * Restore to operational mode.
363 		 */
364 		error = cyttsp_exit_bl_mode(ts);
365 		if (error) {
366 			dev_err(ts->dev,
367 				"Could not return to operational mode, err: %d\n",
368 				error);
369 			ts->state = CY_IDLE_STATE;
370 		}
371 	} else {
372 		cyttsp_report_tchdata(ts);
373 	}
374 
375 out:
376 	return IRQ_HANDLED;
377 }
378 
379 static int cyttsp_power_on(struct cyttsp *ts)
380 {
381 	int error;
382 
383 	error = cyttsp_soft_reset(ts);
384 	if (error)
385 		return error;
386 
387 	error = cyttsp_load_bl_regs(ts);
388 	if (error)
389 		return error;
390 
391 	if (GET_BOOTLOADERMODE(ts->bl_data.bl_status) &&
392 	    IS_VALID_APP(ts->bl_data.bl_status)) {
393 		error = cyttsp_exit_bl_mode(ts);
394 		if (error)
395 			return error;
396 	}
397 
398 	if (GET_HSTMODE(ts->bl_data.bl_file) != CY_OPERATE_MODE ||
399 	    IS_OPERATIONAL_ERR(ts->bl_data.bl_status)) {
400 		return -ENODEV;
401 	}
402 
403 	error = cyttsp_set_sysinfo_mode(ts);
404 	if (error)
405 		return error;
406 
407 	error = cyttsp_set_sysinfo_regs(ts);
408 	if (error)
409 		return error;
410 
411 	error = cyttsp_set_operational_mode(ts);
412 	if (error)
413 		return error;
414 
415 	/* init active distance */
416 	error = cyttsp_act_dist_setup(ts);
417 	if (error)
418 		return error;
419 
420 	ts->state = CY_ACTIVE_STATE;
421 
422 	return 0;
423 }
424 
425 static int cyttsp_enable(struct cyttsp *ts)
426 {
427 	int error;
428 
429 	/*
430 	 * The device firmware can wake on an I2C or SPI memory slave
431 	 * address match. So just reading a register is sufficient to
432 	 * wake up the device. The first read attempt will fail but it
433 	 * will wake it up making the second read attempt successful.
434 	 */
435 	error = ttsp_read_block_data(ts, CY_REG_BASE,
436 				     sizeof(ts->xy_data), &ts->xy_data);
437 	if (error)
438 		return error;
439 
440 	if (GET_HSTMODE(ts->xy_data.hst_mode))
441 		return -EIO;
442 
443 	enable_irq(ts->irq);
444 
445 	return 0;
446 }
447 
448 static int cyttsp_disable(struct cyttsp *ts)
449 {
450 	int error;
451 
452 	error = ttsp_send_command(ts, CY_LOW_POWER_MODE);
453 	if (error)
454 		return error;
455 
456 	disable_irq(ts->irq);
457 
458 	return 0;
459 }
460 
461 #ifdef CONFIG_PM_SLEEP
462 static int cyttsp_suspend(struct device *dev)
463 {
464 	struct cyttsp *ts = dev_get_drvdata(dev);
465 	int retval = 0;
466 
467 	mutex_lock(&ts->input->mutex);
468 
469 	if (ts->input->users) {
470 		retval = cyttsp_disable(ts);
471 		if (retval == 0)
472 			ts->suspended = true;
473 	}
474 
475 	mutex_unlock(&ts->input->mutex);
476 
477 	return retval;
478 }
479 
480 static int cyttsp_resume(struct device *dev)
481 {
482 	struct cyttsp *ts = dev_get_drvdata(dev);
483 
484 	mutex_lock(&ts->input->mutex);
485 
486 	if (ts->input->users)
487 		cyttsp_enable(ts);
488 
489 	ts->suspended = false;
490 
491 	mutex_unlock(&ts->input->mutex);
492 
493 	return 0;
494 }
495 
496 #endif
497 
498 SIMPLE_DEV_PM_OPS(cyttsp_pm_ops, cyttsp_suspend, cyttsp_resume);
499 EXPORT_SYMBOL_GPL(cyttsp_pm_ops);
500 
501 static int cyttsp_open(struct input_dev *dev)
502 {
503 	struct cyttsp *ts = input_get_drvdata(dev);
504 	int retval = 0;
505 
506 	if (!ts->suspended)
507 		retval = cyttsp_enable(ts);
508 
509 	return retval;
510 }
511 
512 static void cyttsp_close(struct input_dev *dev)
513 {
514 	struct cyttsp *ts = input_get_drvdata(dev);
515 
516 	if (!ts->suspended)
517 		cyttsp_disable(ts);
518 }
519 
520 struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
521 			    struct device *dev, int irq, size_t xfer_buf_size)
522 {
523 	const struct cyttsp_platform_data *pdata = dev->platform_data;
524 	struct cyttsp *ts;
525 	struct input_dev *input_dev;
526 	int error;
527 
528 	if (!pdata || !pdata->name || irq <= 0) {
529 		error = -EINVAL;
530 		goto err_out;
531 	}
532 
533 	ts = kzalloc(sizeof(*ts) + xfer_buf_size, GFP_KERNEL);
534 	input_dev = input_allocate_device();
535 	if (!ts || !input_dev) {
536 		error = -ENOMEM;
537 		goto err_free_mem;
538 	}
539 
540 	ts->dev = dev;
541 	ts->input = input_dev;
542 	ts->pdata = dev->platform_data;
543 	ts->bus_ops = bus_ops;
544 	ts->irq = irq;
545 
546 	init_completion(&ts->bl_ready);
547 	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
548 
549 	if (pdata->init) {
550 		error = pdata->init();
551 		if (error) {
552 			dev_err(ts->dev, "platform init failed, err: %d\n",
553 				error);
554 			goto err_free_mem;
555 		}
556 	}
557 
558 	input_dev->name = pdata->name;
559 	input_dev->phys = ts->phys;
560 	input_dev->id.bustype = bus_ops->bustype;
561 	input_dev->dev.parent = ts->dev;
562 
563 	input_dev->open = cyttsp_open;
564 	input_dev->close = cyttsp_close;
565 
566 	input_set_drvdata(input_dev, ts);
567 
568 	__set_bit(EV_ABS, input_dev->evbit);
569 	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
570 			     0, pdata->maxx, 0, 0);
571 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
572 			     0, pdata->maxy, 0, 0);
573 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
574 			     0, CY_MAXZ, 0, 0);
575 
576 	input_mt_init_slots(input_dev, CY_MAX_ID, 0);
577 
578 	error = request_threaded_irq(ts->irq, NULL, cyttsp_irq,
579 				     IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
580 				     pdata->name, ts);
581 	if (error) {
582 		dev_err(ts->dev, "failed to request IRQ %d, err: %d\n",
583 			ts->irq, error);
584 		goto err_platform_exit;
585 	}
586 
587 	disable_irq(ts->irq);
588 
589 	error = cyttsp_power_on(ts);
590 	if (error)
591 		goto err_free_irq;
592 
593 	error = input_register_device(input_dev);
594 	if (error) {
595 		dev_err(ts->dev, "failed to register input device: %d\n",
596 			error);
597 		goto err_free_irq;
598 	}
599 
600 	return ts;
601 
602 err_free_irq:
603 	free_irq(ts->irq, ts);
604 err_platform_exit:
605 	if (pdata->exit)
606 		pdata->exit();
607 err_free_mem:
608 	input_free_device(input_dev);
609 	kfree(ts);
610 err_out:
611 	return ERR_PTR(error);
612 }
613 EXPORT_SYMBOL_GPL(cyttsp_probe);
614 
615 void cyttsp_remove(struct cyttsp *ts)
616 {
617 	free_irq(ts->irq, ts);
618 	input_unregister_device(ts->input);
619 	if (ts->pdata->exit)
620 		ts->pdata->exit();
621 	kfree(ts);
622 }
623 EXPORT_SYMBOL_GPL(cyttsp_remove);
624 
625 MODULE_LICENSE("GPL");
626 MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard touchscreen driver core");
627 MODULE_AUTHOR("Cypress");
628