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