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