1 /*
2  * Cypress Trackpad PS/2 mouse driver
3  *
4  * Copyright (c) 2012 Cypress Semiconductor Corporation.
5  *
6  * Author:
7  *   Dudley Du <dudl@cypress.com>
8  *
9  * Additional contributors include:
10  *   Kamal Mostafa <kamal@canonical.com>
11  *   Kyle Fazzari <git@status.e4ward.com>
12  *
13  * This program is free software; you can redistribute it and/or modify it
14  * under the terms of the GNU General Public License version 2 as published by
15  * the Free Software Foundation.
16  */
17 
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/slab.h>
22 #include <linux/serio.h>
23 #include <linux/libps2.h>
24 #include <linux/input.h>
25 #include <linux/input/mt.h>
26 #include <linux/sched.h>
27 #include <linux/wait.h>
28 
29 #include "cypress_ps2.h"
30 
31 #undef CYTP_DEBUG_VERBOSE  /* define this and DEBUG for more verbose dump */
32 
33 static void cypress_set_packet_size(struct psmouse *psmouse, unsigned int n)
34 {
35 	struct cytp_data *cytp = psmouse->private;
36 	cytp->pkt_size = n;
37 }
38 
39 static const unsigned char cytp_rate[] = {10, 20, 40, 60, 100, 200};
40 static const unsigned char cytp_resolution[] = {0x00, 0x01, 0x02, 0x03};
41 
42 static int cypress_ps2_sendbyte(struct psmouse *psmouse, int value)
43 {
44 	struct ps2dev *ps2dev = &psmouse->ps2dev;
45 
46 	if (ps2_sendbyte(ps2dev, value & 0xff, CYTP_CMD_TIMEOUT) < 0) {
47 		psmouse_dbg(psmouse,
48 				"sending command 0x%02x failed, resp 0x%02x\n",
49 				value & 0xff, ps2dev->nak);
50 		if (ps2dev->nak == CYTP_PS2_RETRY)
51 			return CYTP_PS2_RETRY;
52 		else
53 			return CYTP_PS2_ERROR;
54 	}
55 
56 #ifdef CYTP_DEBUG_VERBOSE
57 	psmouse_dbg(psmouse, "sending command 0x%02x succeeded, resp 0xfa\n",
58 			value & 0xff);
59 #endif
60 
61 	return 0;
62 }
63 
64 static int cypress_ps2_ext_cmd(struct psmouse *psmouse, unsigned short cmd,
65 			       unsigned char data)
66 {
67 	struct ps2dev *ps2dev = &psmouse->ps2dev;
68 	int tries = CYTP_PS2_CMD_TRIES;
69 	int rc;
70 
71 	ps2_begin_command(ps2dev);
72 
73 	do {
74 		/*
75 		 * Send extension command byte (0xE8 or 0xF3).
76 		 * If sending the command fails, send recovery command
77 		 * to make the device return to the ready state.
78 		 */
79 		rc = cypress_ps2_sendbyte(psmouse, cmd & 0xff);
80 		if (rc == CYTP_PS2_RETRY) {
81 			rc = cypress_ps2_sendbyte(psmouse, 0x00);
82 			if (rc == CYTP_PS2_RETRY)
83 				rc = cypress_ps2_sendbyte(psmouse, 0x0a);
84 		}
85 		if (rc == CYTP_PS2_ERROR)
86 			continue;
87 
88 		rc = cypress_ps2_sendbyte(psmouse, data);
89 		if (rc == CYTP_PS2_RETRY)
90 			rc = cypress_ps2_sendbyte(psmouse, data);
91 		if (rc == CYTP_PS2_ERROR)
92 			continue;
93 		else
94 			break;
95 	} while (--tries > 0);
96 
97 	ps2_end_command(ps2dev);
98 
99 	return rc;
100 }
101 
102 static int cypress_ps2_read_cmd_status(struct psmouse *psmouse,
103 				       unsigned char cmd,
104 				       unsigned char *param)
105 {
106 	int rc;
107 	struct ps2dev *ps2dev = &psmouse->ps2dev;
108 	enum psmouse_state old_state;
109 	int pktsize;
110 
111 	ps2_begin_command(&psmouse->ps2dev);
112 
113 	old_state = psmouse->state;
114 	psmouse->state = PSMOUSE_CMD_MODE;
115 	psmouse->pktcnt = 0;
116 
117 	pktsize = (cmd == CYTP_CMD_READ_TP_METRICS) ? 8 : 3;
118 	memset(param, 0, pktsize);
119 
120 	rc = cypress_ps2_sendbyte(psmouse, 0xe9);
121 	if (rc < 0)
122 		goto out;
123 
124 	wait_event_timeout(ps2dev->wait,
125 			(psmouse->pktcnt >= pktsize),
126 			msecs_to_jiffies(CYTP_CMD_TIMEOUT));
127 
128 	memcpy(param, psmouse->packet, pktsize);
129 
130 	psmouse_dbg(psmouse, "Command 0x%02x response data (0x): %*ph\n",
131 			cmd, pktsize, param);
132 
133 out:
134 	psmouse->state = old_state;
135 	psmouse->pktcnt = 0;
136 
137 	ps2_end_command(&psmouse->ps2dev);
138 
139 	return rc;
140 }
141 
142 static bool cypress_verify_cmd_state(struct psmouse *psmouse,
143 				     unsigned char cmd, unsigned char *param)
144 {
145 	bool rate_match = false;
146 	bool resolution_match = false;
147 	int i;
148 
149 	/* callers will do further checking. */
150 	if (cmd == CYTP_CMD_READ_CYPRESS_ID ||
151 	    cmd == CYTP_CMD_STANDARD_MODE ||
152 	    cmd == CYTP_CMD_READ_TP_METRICS)
153 		return true;
154 
155 	if ((~param[0] & DFLT_RESP_BITS_VALID) == DFLT_RESP_BITS_VALID &&
156 	    (param[0] & DFLT_RESP_BIT_MODE) == DFLT_RESP_STREAM_MODE) {
157 		for (i = 0; i < sizeof(cytp_resolution); i++)
158 			if (cytp_resolution[i] == param[1])
159 				resolution_match = true;
160 
161 		for (i = 0; i < sizeof(cytp_rate); i++)
162 			if (cytp_rate[i] == param[2])
163 				rate_match = true;
164 
165 		if (resolution_match && rate_match)
166 			return true;
167 	}
168 
169 	psmouse_dbg(psmouse, "verify cmd state failed.\n");
170 	return false;
171 }
172 
173 static int cypress_send_ext_cmd(struct psmouse *psmouse, unsigned char cmd,
174 				unsigned char *param)
175 {
176 	int tries = CYTP_PS2_CMD_TRIES;
177 	int rc;
178 
179 	psmouse_dbg(psmouse, "send extension cmd 0x%02x, [%d %d %d %d]\n",
180 		 cmd, DECODE_CMD_AA(cmd), DECODE_CMD_BB(cmd),
181 		 DECODE_CMD_CC(cmd), DECODE_CMD_DD(cmd));
182 
183 	do {
184 		cypress_ps2_ext_cmd(psmouse,
185 				    PSMOUSE_CMD_SETRES, DECODE_CMD_DD(cmd));
186 		cypress_ps2_ext_cmd(psmouse,
187 				    PSMOUSE_CMD_SETRES, DECODE_CMD_CC(cmd));
188 		cypress_ps2_ext_cmd(psmouse,
189 				    PSMOUSE_CMD_SETRES, DECODE_CMD_BB(cmd));
190 		cypress_ps2_ext_cmd(psmouse,
191 				    PSMOUSE_CMD_SETRES, DECODE_CMD_AA(cmd));
192 
193 		rc = cypress_ps2_read_cmd_status(psmouse, cmd, param);
194 		if (rc)
195 			continue;
196 
197 		if (cypress_verify_cmd_state(psmouse, cmd, param))
198 			return 0;
199 
200 	} while (--tries > 0);
201 
202 	return -EIO;
203 }
204 
205 int cypress_detect(struct psmouse *psmouse, bool set_properties)
206 {
207 	unsigned char param[3];
208 
209 	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_READ_CYPRESS_ID, param))
210 		return -ENODEV;
211 
212 	/* Check for Cypress Trackpad signature bytes: 0x33 0xCC */
213 	if (param[0] != 0x33 || param[1] != 0xCC)
214 		return -ENODEV;
215 
216 	if (set_properties) {
217 		psmouse->vendor = "Cypress";
218 		psmouse->name = "Trackpad";
219 	}
220 
221 	return 0;
222 }
223 
224 static int cypress_read_fw_version(struct psmouse *psmouse)
225 {
226 	struct cytp_data *cytp = psmouse->private;
227 	unsigned char param[3];
228 
229 	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_READ_CYPRESS_ID, param))
230 		return -ENODEV;
231 
232 	/* Check for Cypress Trackpad signature bytes: 0x33 0xCC */
233 	if (param[0] != 0x33 || param[1] != 0xCC)
234 		return -ENODEV;
235 
236 	cytp->fw_version = param[2] & FW_VERSION_MASX;
237 	cytp->tp_metrics_supported = (param[2] & TP_METRICS_MASK) ? 1 : 0;
238 
239 	/*
240 	 * Trackpad fw_version 11 (in Dell XPS12) yields a bogus response to
241 	 * CYTP_CMD_READ_TP_METRICS so do not try to use it. LP: #1103594.
242 	 */
243 	if (cytp->fw_version >= 11)
244 		cytp->tp_metrics_supported = 0;
245 
246 	psmouse_dbg(psmouse, "cytp->fw_version = %d\n", cytp->fw_version);
247 	psmouse_dbg(psmouse, "cytp->tp_metrics_supported = %d\n",
248 		 cytp->tp_metrics_supported);
249 
250 	return 0;
251 }
252 
253 static int cypress_read_tp_metrics(struct psmouse *psmouse)
254 {
255 	struct cytp_data *cytp = psmouse->private;
256 	unsigned char param[8];
257 
258 	/* set default values for tp metrics. */
259 	cytp->tp_width = CYTP_DEFAULT_WIDTH;
260 	cytp->tp_high = CYTP_DEFAULT_HIGH;
261 	cytp->tp_max_abs_x = CYTP_ABS_MAX_X;
262 	cytp->tp_max_abs_y = CYTP_ABS_MAX_Y;
263 	cytp->tp_min_pressure = CYTP_MIN_PRESSURE;
264 	cytp->tp_max_pressure = CYTP_MAX_PRESSURE;
265 	cytp->tp_res_x = cytp->tp_max_abs_x / cytp->tp_width;
266 	cytp->tp_res_y = cytp->tp_max_abs_y / cytp->tp_high;
267 
268 	if (!cytp->tp_metrics_supported)
269 		return 0;
270 
271 	memset(param, 0, sizeof(param));
272 	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_READ_TP_METRICS, param) == 0) {
273 		/* Update trackpad parameters. */
274 		cytp->tp_max_abs_x = (param[1] << 8) | param[0];
275 		cytp->tp_max_abs_y = (param[3] << 8) | param[2];
276 		cytp->tp_min_pressure = param[4];
277 		cytp->tp_max_pressure = param[5];
278 	}
279 
280 	if (!cytp->tp_max_pressure ||
281 	    cytp->tp_max_pressure < cytp->tp_min_pressure ||
282 	    !cytp->tp_width || !cytp->tp_high ||
283 	    !cytp->tp_max_abs_x ||
284 	    cytp->tp_max_abs_x < cytp->tp_width ||
285 	    !cytp->tp_max_abs_y ||
286 	    cytp->tp_max_abs_y < cytp->tp_high)
287 		return -EINVAL;
288 
289 	cytp->tp_res_x = cytp->tp_max_abs_x / cytp->tp_width;
290 	cytp->tp_res_y = cytp->tp_max_abs_y / cytp->tp_high;
291 
292 #ifdef CYTP_DEBUG_VERBOSE
293 	psmouse_dbg(psmouse, "Dump trackpad hardware configuration as below:\n");
294 	psmouse_dbg(psmouse, "cytp->tp_width = %d\n", cytp->tp_width);
295 	psmouse_dbg(psmouse, "cytp->tp_high = %d\n", cytp->tp_high);
296 	psmouse_dbg(psmouse, "cytp->tp_max_abs_x = %d\n", cytp->tp_max_abs_x);
297 	psmouse_dbg(psmouse, "cytp->tp_max_abs_y = %d\n", cytp->tp_max_abs_y);
298 	psmouse_dbg(psmouse, "cytp->tp_min_pressure = %d\n", cytp->tp_min_pressure);
299 	psmouse_dbg(psmouse, "cytp->tp_max_pressure = %d\n", cytp->tp_max_pressure);
300 	psmouse_dbg(psmouse, "cytp->tp_res_x = %d\n", cytp->tp_res_x);
301 	psmouse_dbg(psmouse, "cytp->tp_res_y = %d\n", cytp->tp_res_y);
302 
303 	psmouse_dbg(psmouse, "tp_type_APA = %d\n",
304 			(param[6] & TP_METRICS_BIT_APA) ? 1 : 0);
305 	psmouse_dbg(psmouse, "tp_type_MTG = %d\n",
306 			(param[6] & TP_METRICS_BIT_MTG) ? 1 : 0);
307 	psmouse_dbg(psmouse, "tp_palm = %d\n",
308 			(param[6] & TP_METRICS_BIT_PALM) ? 1 : 0);
309 	psmouse_dbg(psmouse, "tp_stubborn = %d\n",
310 			(param[6] & TP_METRICS_BIT_STUBBORN) ? 1 : 0);
311 	psmouse_dbg(psmouse, "tp_1f_jitter = %d\n",
312 			(param[6] & TP_METRICS_BIT_1F_JITTER) >> 2);
313 	psmouse_dbg(psmouse, "tp_2f_jitter = %d\n",
314 			(param[6] & TP_METRICS_BIT_2F_JITTER) >> 4);
315 	psmouse_dbg(psmouse, "tp_1f_spike = %d\n",
316 			param[7] & TP_METRICS_BIT_1F_SPIKE);
317 	psmouse_dbg(psmouse, "tp_2f_spike = %d\n",
318 			(param[7] & TP_METRICS_BIT_2F_SPIKE) >> 2);
319 	psmouse_dbg(psmouse, "tp_abs_packet_format_set = %d\n",
320 			(param[7] & TP_METRICS_BIT_ABS_PKT_FORMAT_SET) >> 4);
321 #endif
322 
323 	return 0;
324 }
325 
326 static int cypress_query_hardware(struct psmouse *psmouse)
327 {
328 	int ret;
329 
330 	ret = cypress_read_fw_version(psmouse);
331 	if (ret)
332 		return ret;
333 
334 	ret = cypress_read_tp_metrics(psmouse);
335 	if (ret)
336 		return ret;
337 
338 	return 0;
339 }
340 
341 static int cypress_set_absolute_mode(struct psmouse *psmouse)
342 {
343 	struct cytp_data *cytp = psmouse->private;
344 	unsigned char param[3];
345 
346 	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_ABS_WITH_PRESSURE_MODE, param) < 0)
347 		return -1;
348 
349 	cytp->mode = (cytp->mode & ~CYTP_BIT_ABS_REL_MASK)
350 			| CYTP_BIT_ABS_PRESSURE;
351 	cypress_set_packet_size(psmouse, 5);
352 
353 	return 0;
354 }
355 
356 /*
357  * Reset trackpad device.
358  * This is also the default mode when trackpad powered on.
359  */
360 static void cypress_reset(struct psmouse *psmouse)
361 {
362 	struct cytp_data *cytp = psmouse->private;
363 
364 	cytp->mode = 0;
365 
366 	psmouse_reset(psmouse);
367 }
368 
369 static int cypress_set_input_params(struct input_dev *input,
370 				    struct cytp_data *cytp)
371 {
372 	int ret;
373 
374 	if (!cytp->tp_res_x || !cytp->tp_res_y)
375 		return -EINVAL;
376 
377 	__set_bit(EV_ABS, input->evbit);
378 	input_set_abs_params(input, ABS_X, 0, cytp->tp_max_abs_x, 0, 0);
379 	input_set_abs_params(input, ABS_Y, 0, cytp->tp_max_abs_y, 0, 0);
380 	input_set_abs_params(input, ABS_PRESSURE,
381 			     cytp->tp_min_pressure, cytp->tp_max_pressure, 0, 0);
382 	input_set_abs_params(input, ABS_TOOL_WIDTH, 0, 255, 0, 0);
383 
384 	/* finger position */
385 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, cytp->tp_max_abs_x, 0, 0);
386 	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, cytp->tp_max_abs_y, 0, 0);
387 	input_set_abs_params(input, ABS_MT_PRESSURE, 0, 255, 0, 0);
388 
389 	ret = input_mt_init_slots(input, CYTP_MAX_MT_SLOTS,
390 			INPUT_MT_DROP_UNUSED|INPUT_MT_TRACK);
391 	if (ret < 0)
392 		return ret;
393 
394 	__set_bit(INPUT_PROP_SEMI_MT, input->propbit);
395 
396 	input_abs_set_res(input, ABS_X, cytp->tp_res_x);
397 	input_abs_set_res(input, ABS_Y, cytp->tp_res_y);
398 
399 	input_abs_set_res(input, ABS_MT_POSITION_X, cytp->tp_res_x);
400 	input_abs_set_res(input, ABS_MT_POSITION_Y, cytp->tp_res_y);
401 
402 	__set_bit(BTN_TOUCH, input->keybit);
403 	__set_bit(BTN_TOOL_FINGER, input->keybit);
404 	__set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
405 	__set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
406 	__set_bit(BTN_TOOL_QUADTAP, input->keybit);
407 	__set_bit(BTN_TOOL_QUINTTAP, input->keybit);
408 
409 	__clear_bit(EV_REL, input->evbit);
410 	__clear_bit(REL_X, input->relbit);
411 	__clear_bit(REL_Y, input->relbit);
412 
413 	__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
414 	__set_bit(EV_KEY, input->evbit);
415 	__set_bit(BTN_LEFT, input->keybit);
416 	__set_bit(BTN_RIGHT, input->keybit);
417 	__set_bit(BTN_MIDDLE, input->keybit);
418 
419 	input_set_drvdata(input, cytp);
420 
421 	return 0;
422 }
423 
424 static int cypress_get_finger_count(unsigned char header_byte)
425 {
426 	unsigned char bits6_7;
427 	int finger_count;
428 
429 	bits6_7 = header_byte >> 6;
430 	finger_count = bits6_7 & 0x03;
431 
432 	if (finger_count == 1)
433 		return 1;
434 
435 	if (header_byte & ABS_HSCROLL_BIT) {
436 		/* HSCROLL gets added on to 0 finger count. */
437 		switch (finger_count) {
438 			case 0:	return 4;
439 			case 2: return 5;
440 			default:
441 				/* Invalid contact (e.g. palm). Ignore it. */
442 				return -1;
443 		}
444 	}
445 
446 	return finger_count;
447 }
448 
449 
450 static int cypress_parse_packet(struct psmouse *psmouse,
451 				struct cytp_data *cytp, struct cytp_report_data *report_data)
452 {
453 	unsigned char *packet = psmouse->packet;
454 	unsigned char header_byte = packet[0];
455 	int contact_cnt;
456 
457 	memset(report_data, 0, sizeof(struct cytp_report_data));
458 
459 	contact_cnt = cypress_get_finger_count(header_byte);
460 
461 	if (contact_cnt < 0) /* e.g. palm detect */
462 		return -EINVAL;
463 
464 	report_data->contact_cnt = contact_cnt;
465 
466 	report_data->tap = (header_byte & ABS_MULTIFINGER_TAP) ? 1 : 0;
467 
468 	if (report_data->contact_cnt == 1) {
469 		report_data->contacts[0].x =
470 			((packet[1] & 0x70) << 4) | packet[2];
471 		report_data->contacts[0].y =
472 			((packet[1] & 0x07) << 8) | packet[3];
473 		if (cytp->mode & CYTP_BIT_ABS_PRESSURE)
474 			report_data->contacts[0].z = packet[4];
475 
476 	} else if (report_data->contact_cnt >= 2) {
477 		report_data->contacts[0].x =
478 			((packet[1] & 0x70) << 4) | packet[2];
479 		report_data->contacts[0].y =
480 			((packet[1] & 0x07) << 8) | packet[3];
481 		if (cytp->mode & CYTP_BIT_ABS_PRESSURE)
482 			report_data->contacts[0].z = packet[4];
483 
484 		report_data->contacts[1].x =
485 			((packet[5] & 0xf0) << 4) | packet[6];
486 		report_data->contacts[1].y =
487 			((packet[5] & 0x0f) << 8) | packet[7];
488 		if (cytp->mode & CYTP_BIT_ABS_PRESSURE)
489 			report_data->contacts[1].z = report_data->contacts[0].z;
490 	}
491 
492 	report_data->left = (header_byte & BTN_LEFT_BIT) ? 1 : 0;
493 	report_data->right = (header_byte & BTN_RIGHT_BIT) ? 1 : 0;
494 
495 	/*
496 	 * This is only true if one of the mouse buttons were tapped.  Make
497 	 * sure it doesn't turn into a click. The regular tap-to-click
498 	 * functionality will handle that on its own. If we don't do this,
499 	 * disabling tap-to-click won't affect the mouse button zones.
500 	 */
501 	if (report_data->tap)
502 		report_data->left = 0;
503 
504 #ifdef CYTP_DEBUG_VERBOSE
505 	{
506 		int i;
507 		int n = report_data->contact_cnt;
508 		psmouse_dbg(psmouse, "Dump parsed report data as below:\n");
509 		psmouse_dbg(psmouse, "contact_cnt = %d\n",
510 			report_data->contact_cnt);
511 		if (n > CYTP_MAX_MT_SLOTS)
512 		    n = CYTP_MAX_MT_SLOTS;
513 		for (i = 0; i < n; i++)
514 			psmouse_dbg(psmouse, "contacts[%d] = {%d, %d, %d}\n", i,
515 					report_data->contacts[i].x,
516 					report_data->contacts[i].y,
517 					report_data->contacts[i].z);
518 		psmouse_dbg(psmouse, "left = %d\n", report_data->left);
519 		psmouse_dbg(psmouse, "right = %d\n", report_data->right);
520 		psmouse_dbg(psmouse, "middle = %d\n", report_data->middle);
521 	}
522 #endif
523 
524 	return 0;
525 }
526 
527 static void cypress_process_packet(struct psmouse *psmouse, bool zero_pkt)
528 {
529 	int i;
530 	struct input_dev *input = psmouse->dev;
531 	struct cytp_data *cytp = psmouse->private;
532 	struct cytp_report_data report_data;
533 	struct cytp_contact *contact;
534 	struct input_mt_pos pos[CYTP_MAX_MT_SLOTS];
535 	int slots[CYTP_MAX_MT_SLOTS];
536 	int n;
537 
538 	if (cypress_parse_packet(psmouse, cytp, &report_data))
539 		return;
540 
541 	n = report_data.contact_cnt;
542 
543 	if (n > CYTP_MAX_MT_SLOTS)
544 		n = CYTP_MAX_MT_SLOTS;
545 
546 	for (i = 0; i < n; i++) {
547 		contact = &report_data.contacts[i];
548 		pos[i].x = contact->x;
549 		pos[i].y = contact->y;
550 	}
551 
552 	input_mt_assign_slots(input, slots, pos, n);
553 
554 	for (i = 0; i < n; i++) {
555 		contact = &report_data.contacts[i];
556 		input_mt_slot(input, slots[i]);
557 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
558 		input_report_abs(input, ABS_MT_POSITION_X, contact->x);
559 		input_report_abs(input, ABS_MT_POSITION_Y, contact->y);
560 		input_report_abs(input, ABS_MT_PRESSURE, contact->z);
561 	}
562 
563 	input_mt_sync_frame(input);
564 
565 	input_mt_report_finger_count(input, report_data.contact_cnt);
566 
567 	input_report_key(input, BTN_LEFT, report_data.left);
568 	input_report_key(input, BTN_RIGHT, report_data.right);
569 	input_report_key(input, BTN_MIDDLE, report_data.middle);
570 
571 	input_sync(input);
572 }
573 
574 static psmouse_ret_t cypress_validate_byte(struct psmouse *psmouse)
575 {
576 	int contact_cnt;
577 	int index = psmouse->pktcnt - 1;
578 	unsigned char *packet = psmouse->packet;
579 	struct cytp_data *cytp = psmouse->private;
580 
581 	if (index < 0 || index > cytp->pkt_size)
582 		return PSMOUSE_BAD_DATA;
583 
584 	if (index == 0 && (packet[0] & 0xfc) == 0) {
585 		/* call packet process for reporting finger leave. */
586 		cypress_process_packet(psmouse, 1);
587 		return PSMOUSE_FULL_PACKET;
588 	}
589 
590 	/*
591 	 * Perform validation (and adjust packet size) based only on the
592 	 * first byte; allow all further bytes through.
593 	 */
594 	if (index != 0)
595 		return PSMOUSE_GOOD_DATA;
596 
597 	/*
598 	 * If absolute/relative mode bit has not been set yet, just pass
599 	 * the byte through.
600 	 */
601 	if ((cytp->mode & CYTP_BIT_ABS_REL_MASK) == 0)
602 		return PSMOUSE_GOOD_DATA;
603 
604 	if ((packet[0] & 0x08) == 0x08)
605 		return PSMOUSE_BAD_DATA;
606 
607 	contact_cnt = cypress_get_finger_count(packet[0]);
608 
609 	if (contact_cnt < 0)
610 		return PSMOUSE_BAD_DATA;
611 
612 	if (cytp->mode & CYTP_BIT_ABS_NO_PRESSURE)
613 		cypress_set_packet_size(psmouse, contact_cnt == 2 ? 7 : 4);
614 	else
615 		cypress_set_packet_size(psmouse, contact_cnt == 2 ? 8 : 5);
616 
617 	return PSMOUSE_GOOD_DATA;
618 }
619 
620 static psmouse_ret_t cypress_protocol_handler(struct psmouse *psmouse)
621 {
622 	struct cytp_data *cytp = psmouse->private;
623 
624 	if (psmouse->pktcnt >= cytp->pkt_size) {
625 		cypress_process_packet(psmouse, 0);
626 		return PSMOUSE_FULL_PACKET;
627 	}
628 
629 	return cypress_validate_byte(psmouse);
630 }
631 
632 static void cypress_set_rate(struct psmouse *psmouse, unsigned int rate)
633 {
634 	struct cytp_data *cytp = psmouse->private;
635 
636 	if (rate >= 80) {
637 		psmouse->rate = 80;
638 		cytp->mode |= CYTP_BIT_HIGH_RATE;
639 	} else {
640 		psmouse->rate = 40;
641 		cytp->mode &= ~CYTP_BIT_HIGH_RATE;
642 	}
643 
644 	ps2_command(&psmouse->ps2dev, (unsigned char *)&psmouse->rate,
645 		    PSMOUSE_CMD_SETRATE);
646 }
647 
648 static void cypress_disconnect(struct psmouse *psmouse)
649 {
650 	cypress_reset(psmouse);
651 	kfree(psmouse->private);
652 	psmouse->private = NULL;
653 }
654 
655 static int cypress_reconnect(struct psmouse *psmouse)
656 {
657 	int tries = CYTP_PS2_CMD_TRIES;
658 	int rc;
659 
660 	do {
661 		cypress_reset(psmouse);
662 		rc = cypress_detect(psmouse, false);
663 	} while (rc && (--tries > 0));
664 
665 	if (rc) {
666 		psmouse_err(psmouse, "Reconnect: unable to detect trackpad.\n");
667 		return -1;
668 	}
669 
670 	if (cypress_set_absolute_mode(psmouse)) {
671 		psmouse_err(psmouse, "Reconnect: Unable to initialize Cypress absolute mode.\n");
672 		return -1;
673 	}
674 
675 	return 0;
676 }
677 
678 int cypress_init(struct psmouse *psmouse)
679 {
680 	struct cytp_data *cytp;
681 
682 	cytp = (struct cytp_data *)kzalloc(sizeof(struct cytp_data), GFP_KERNEL);
683 	psmouse->private = (void *)cytp;
684 	if (cytp == NULL)
685 		return -ENOMEM;
686 
687 	cypress_reset(psmouse);
688 
689 	psmouse->pktsize = 8;
690 
691 	if (cypress_query_hardware(psmouse)) {
692 		psmouse_err(psmouse, "Unable to query Trackpad hardware.\n");
693 		goto err_exit;
694 	}
695 
696 	if (cypress_set_absolute_mode(psmouse)) {
697 		psmouse_err(psmouse, "init: Unable to initialize Cypress absolute mode.\n");
698 		goto err_exit;
699 	}
700 
701 	if (cypress_set_input_params(psmouse->dev, cytp) < 0) {
702 		psmouse_err(psmouse, "init: Unable to set input params.\n");
703 		goto err_exit;
704 	}
705 
706 	psmouse->model = 1;
707 	psmouse->protocol_handler = cypress_protocol_handler;
708 	psmouse->set_rate = cypress_set_rate;
709 	psmouse->disconnect = cypress_disconnect;
710 	psmouse->reconnect = cypress_reconnect;
711 	psmouse->cleanup = cypress_reset;
712 	psmouse->resync_time = 0;
713 
714 	return 0;
715 
716 err_exit:
717 	/*
718 	 * Reset Cypress Trackpad as a standard mouse. Then
719 	 * let psmouse driver commmunicating with it as default PS2 mouse.
720 	 */
721 	cypress_reset(psmouse);
722 
723 	psmouse->private = NULL;
724 	kfree(cytp);
725 
726 	return -1;
727 }
728 
729 bool cypress_supported(void)
730 {
731 	return true;
732 }
733