1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Cypress Trackpad PS/2 mouse driver
4  *
5  * Copyright (c) 2012 Cypress Semiconductor Corporation.
6  *
7  * Author:
8  *   Dudley Du <dudl@cypress.com>
9  *
10  * Additional contributors include:
11  *   Kamal Mostafa <kamal@canonical.com>
12  *   Kyle Fazzari <git@status.e4ward.com>
13  */
14 
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/slab.h>
18 #include <linux/serio.h>
19 #include <linux/libps2.h>
20 #include <linux/input.h>
21 #include <linux/input/mt.h>
22 #include <linux/sched.h>
23 #include <linux/wait.h>
24 
25 #include "cypress_ps2.h"
26 
27 #undef CYTP_DEBUG_VERBOSE  /* define this and DEBUG for more verbose dump */
28 
29 static void cypress_set_packet_size(struct psmouse *psmouse, unsigned int n)
30 {
31 	struct cytp_data *cytp = psmouse->private;
32 	cytp->pkt_size = n;
33 }
34 
35 static const unsigned char cytp_rate[] = {10, 20, 40, 60, 100, 200};
36 static const unsigned char cytp_resolution[] = {0x00, 0x01, 0x02, 0x03};
37 
38 static int cypress_ps2_sendbyte(struct psmouse *psmouse, int value)
39 {
40 	struct ps2dev *ps2dev = &psmouse->ps2dev;
41 
42 	if (ps2_sendbyte(ps2dev, value & 0xff, CYTP_CMD_TIMEOUT) < 0) {
43 		psmouse_dbg(psmouse,
44 				"sending command 0x%02x failed, resp 0x%02x\n",
45 				value & 0xff, ps2dev->nak);
46 		if (ps2dev->nak == CYTP_PS2_RETRY)
47 			return CYTP_PS2_RETRY;
48 		else
49 			return CYTP_PS2_ERROR;
50 	}
51 
52 #ifdef CYTP_DEBUG_VERBOSE
53 	psmouse_dbg(psmouse, "sending command 0x%02x succeeded, resp 0xfa\n",
54 			value & 0xff);
55 #endif
56 
57 	return 0;
58 }
59 
60 static int cypress_ps2_ext_cmd(struct psmouse *psmouse, unsigned short cmd,
61 			       unsigned char data)
62 {
63 	struct ps2dev *ps2dev = &psmouse->ps2dev;
64 	int tries = CYTP_PS2_CMD_TRIES;
65 	int rc;
66 
67 	ps2_begin_command(ps2dev);
68 
69 	do {
70 		/*
71 		 * Send extension command byte (0xE8 or 0xF3).
72 		 * If sending the command fails, send recovery command
73 		 * to make the device return to the ready state.
74 		 */
75 		rc = cypress_ps2_sendbyte(psmouse, cmd & 0xff);
76 		if (rc == CYTP_PS2_RETRY) {
77 			rc = cypress_ps2_sendbyte(psmouse, 0x00);
78 			if (rc == CYTP_PS2_RETRY)
79 				rc = cypress_ps2_sendbyte(psmouse, 0x0a);
80 		}
81 		if (rc == CYTP_PS2_ERROR)
82 			continue;
83 
84 		rc = cypress_ps2_sendbyte(psmouse, data);
85 		if (rc == CYTP_PS2_RETRY)
86 			rc = cypress_ps2_sendbyte(psmouse, data);
87 		if (rc == CYTP_PS2_ERROR)
88 			continue;
89 		else
90 			break;
91 	} while (--tries > 0);
92 
93 	ps2_end_command(ps2dev);
94 
95 	return rc;
96 }
97 
98 static int cypress_ps2_read_cmd_status(struct psmouse *psmouse,
99 				       unsigned char cmd,
100 				       unsigned char *param)
101 {
102 	int rc;
103 	struct ps2dev *ps2dev = &psmouse->ps2dev;
104 	enum psmouse_state old_state;
105 	int pktsize;
106 
107 	ps2_begin_command(ps2dev);
108 
109 	old_state = psmouse->state;
110 	psmouse->state = PSMOUSE_CMD_MODE;
111 	psmouse->pktcnt = 0;
112 
113 	pktsize = (cmd == CYTP_CMD_READ_TP_METRICS) ? 8 : 3;
114 	memset(param, 0, pktsize);
115 
116 	rc = cypress_ps2_sendbyte(psmouse, 0xe9);
117 	if (rc < 0)
118 		goto out;
119 
120 	wait_event_timeout(ps2dev->wait,
121 			(psmouse->pktcnt >= pktsize),
122 			msecs_to_jiffies(CYTP_CMD_TIMEOUT));
123 
124 	memcpy(param, psmouse->packet, pktsize);
125 
126 	psmouse_dbg(psmouse, "Command 0x%02x response data (0x): %*ph\n",
127 			cmd, pktsize, param);
128 
129 out:
130 	psmouse->state = old_state;
131 	psmouse->pktcnt = 0;
132 
133 	ps2_end_command(ps2dev);
134 
135 	return rc;
136 }
137 
138 static bool cypress_verify_cmd_state(struct psmouse *psmouse,
139 				     unsigned char cmd, unsigned char *param)
140 {
141 	bool rate_match = false;
142 	bool resolution_match = false;
143 	int i;
144 
145 	/* callers will do further checking. */
146 	if (cmd == CYTP_CMD_READ_CYPRESS_ID ||
147 	    cmd == CYTP_CMD_STANDARD_MODE ||
148 	    cmd == CYTP_CMD_READ_TP_METRICS)
149 		return true;
150 
151 	if ((~param[0] & DFLT_RESP_BITS_VALID) == DFLT_RESP_BITS_VALID &&
152 	    (param[0] & DFLT_RESP_BIT_MODE) == DFLT_RESP_STREAM_MODE) {
153 		for (i = 0; i < sizeof(cytp_resolution); i++)
154 			if (cytp_resolution[i] == param[1])
155 				resolution_match = true;
156 
157 		for (i = 0; i < sizeof(cytp_rate); i++)
158 			if (cytp_rate[i] == param[2])
159 				rate_match = true;
160 
161 		if (resolution_match && rate_match)
162 			return true;
163 	}
164 
165 	psmouse_dbg(psmouse, "verify cmd state failed.\n");
166 	return false;
167 }
168 
169 static int cypress_send_ext_cmd(struct psmouse *psmouse, unsigned char cmd,
170 				unsigned char *param)
171 {
172 	int tries = CYTP_PS2_CMD_TRIES;
173 	int rc;
174 
175 	psmouse_dbg(psmouse, "send extension cmd 0x%02x, [%d %d %d %d]\n",
176 		 cmd, DECODE_CMD_AA(cmd), DECODE_CMD_BB(cmd),
177 		 DECODE_CMD_CC(cmd), DECODE_CMD_DD(cmd));
178 
179 	do {
180 		cypress_ps2_ext_cmd(psmouse,
181 				    PSMOUSE_CMD_SETRES, DECODE_CMD_DD(cmd));
182 		cypress_ps2_ext_cmd(psmouse,
183 				    PSMOUSE_CMD_SETRES, DECODE_CMD_CC(cmd));
184 		cypress_ps2_ext_cmd(psmouse,
185 				    PSMOUSE_CMD_SETRES, DECODE_CMD_BB(cmd));
186 		cypress_ps2_ext_cmd(psmouse,
187 				    PSMOUSE_CMD_SETRES, DECODE_CMD_AA(cmd));
188 
189 		rc = cypress_ps2_read_cmd_status(psmouse, cmd, param);
190 		if (rc)
191 			continue;
192 
193 		if (cypress_verify_cmd_state(psmouse, cmd, param))
194 			return 0;
195 
196 	} while (--tries > 0);
197 
198 	return -EIO;
199 }
200 
201 int cypress_detect(struct psmouse *psmouse, bool set_properties)
202 {
203 	unsigned char param[3];
204 
205 	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_READ_CYPRESS_ID, param))
206 		return -ENODEV;
207 
208 	/* Check for Cypress Trackpad signature bytes: 0x33 0xCC */
209 	if (param[0] != 0x33 || param[1] != 0xCC)
210 		return -ENODEV;
211 
212 	if (set_properties) {
213 		psmouse->vendor = "Cypress";
214 		psmouse->name = "Trackpad";
215 	}
216 
217 	return 0;
218 }
219 
220 static int cypress_read_fw_version(struct psmouse *psmouse)
221 {
222 	struct cytp_data *cytp = psmouse->private;
223 	unsigned char param[3];
224 
225 	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_READ_CYPRESS_ID, param))
226 		return -ENODEV;
227 
228 	/* Check for Cypress Trackpad signature bytes: 0x33 0xCC */
229 	if (param[0] != 0x33 || param[1] != 0xCC)
230 		return -ENODEV;
231 
232 	cytp->fw_version = param[2] & FW_VERSION_MASX;
233 	cytp->tp_metrics_supported = (param[2] & TP_METRICS_MASK) ? 1 : 0;
234 
235 	/*
236 	 * Trackpad fw_version 11 (in Dell XPS12) yields a bogus response to
237 	 * CYTP_CMD_READ_TP_METRICS so do not try to use it. LP: #1103594.
238 	 */
239 	if (cytp->fw_version >= 11)
240 		cytp->tp_metrics_supported = 0;
241 
242 	psmouse_dbg(psmouse, "cytp->fw_version = %d\n", cytp->fw_version);
243 	psmouse_dbg(psmouse, "cytp->tp_metrics_supported = %d\n",
244 		 cytp->tp_metrics_supported);
245 
246 	return 0;
247 }
248 
249 static int cypress_read_tp_metrics(struct psmouse *psmouse)
250 {
251 	struct cytp_data *cytp = psmouse->private;
252 	unsigned char param[8];
253 
254 	/* set default values for tp metrics. */
255 	cytp->tp_width = CYTP_DEFAULT_WIDTH;
256 	cytp->tp_high = CYTP_DEFAULT_HIGH;
257 	cytp->tp_max_abs_x = CYTP_ABS_MAX_X;
258 	cytp->tp_max_abs_y = CYTP_ABS_MAX_Y;
259 	cytp->tp_min_pressure = CYTP_MIN_PRESSURE;
260 	cytp->tp_max_pressure = CYTP_MAX_PRESSURE;
261 	cytp->tp_res_x = cytp->tp_max_abs_x / cytp->tp_width;
262 	cytp->tp_res_y = cytp->tp_max_abs_y / cytp->tp_high;
263 
264 	if (!cytp->tp_metrics_supported)
265 		return 0;
266 
267 	memset(param, 0, sizeof(param));
268 	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_READ_TP_METRICS, param) == 0) {
269 		/* Update trackpad parameters. */
270 		cytp->tp_max_abs_x = (param[1] << 8) | param[0];
271 		cytp->tp_max_abs_y = (param[3] << 8) | param[2];
272 		cytp->tp_min_pressure = param[4];
273 		cytp->tp_max_pressure = param[5];
274 	}
275 
276 	if (!cytp->tp_max_pressure ||
277 	    cytp->tp_max_pressure < cytp->tp_min_pressure ||
278 	    !cytp->tp_width || !cytp->tp_high ||
279 	    !cytp->tp_max_abs_x ||
280 	    cytp->tp_max_abs_x < cytp->tp_width ||
281 	    !cytp->tp_max_abs_y ||
282 	    cytp->tp_max_abs_y < cytp->tp_high)
283 		return -EINVAL;
284 
285 	cytp->tp_res_x = cytp->tp_max_abs_x / cytp->tp_width;
286 	cytp->tp_res_y = cytp->tp_max_abs_y / cytp->tp_high;
287 
288 #ifdef CYTP_DEBUG_VERBOSE
289 	psmouse_dbg(psmouse, "Dump trackpad hardware configuration as below:\n");
290 	psmouse_dbg(psmouse, "cytp->tp_width = %d\n", cytp->tp_width);
291 	psmouse_dbg(psmouse, "cytp->tp_high = %d\n", cytp->tp_high);
292 	psmouse_dbg(psmouse, "cytp->tp_max_abs_x = %d\n", cytp->tp_max_abs_x);
293 	psmouse_dbg(psmouse, "cytp->tp_max_abs_y = %d\n", cytp->tp_max_abs_y);
294 	psmouse_dbg(psmouse, "cytp->tp_min_pressure = %d\n", cytp->tp_min_pressure);
295 	psmouse_dbg(psmouse, "cytp->tp_max_pressure = %d\n", cytp->tp_max_pressure);
296 	psmouse_dbg(psmouse, "cytp->tp_res_x = %d\n", cytp->tp_res_x);
297 	psmouse_dbg(psmouse, "cytp->tp_res_y = %d\n", cytp->tp_res_y);
298 
299 	psmouse_dbg(psmouse, "tp_type_APA = %d\n",
300 			(param[6] & TP_METRICS_BIT_APA) ? 1 : 0);
301 	psmouse_dbg(psmouse, "tp_type_MTG = %d\n",
302 			(param[6] & TP_METRICS_BIT_MTG) ? 1 : 0);
303 	psmouse_dbg(psmouse, "tp_palm = %d\n",
304 			(param[6] & TP_METRICS_BIT_PALM) ? 1 : 0);
305 	psmouse_dbg(psmouse, "tp_stubborn = %d\n",
306 			(param[6] & TP_METRICS_BIT_STUBBORN) ? 1 : 0);
307 	psmouse_dbg(psmouse, "tp_1f_jitter = %d\n",
308 			(param[6] & TP_METRICS_BIT_1F_JITTER) >> 2);
309 	psmouse_dbg(psmouse, "tp_2f_jitter = %d\n",
310 			(param[6] & TP_METRICS_BIT_2F_JITTER) >> 4);
311 	psmouse_dbg(psmouse, "tp_1f_spike = %d\n",
312 			param[7] & TP_METRICS_BIT_1F_SPIKE);
313 	psmouse_dbg(psmouse, "tp_2f_spike = %d\n",
314 			(param[7] & TP_METRICS_BIT_2F_SPIKE) >> 2);
315 	psmouse_dbg(psmouse, "tp_abs_packet_format_set = %d\n",
316 			(param[7] & TP_METRICS_BIT_ABS_PKT_FORMAT_SET) >> 4);
317 #endif
318 
319 	return 0;
320 }
321 
322 static int cypress_query_hardware(struct psmouse *psmouse)
323 {
324 	int ret;
325 
326 	ret = cypress_read_fw_version(psmouse);
327 	if (ret)
328 		return ret;
329 
330 	ret = cypress_read_tp_metrics(psmouse);
331 	if (ret)
332 		return ret;
333 
334 	return 0;
335 }
336 
337 static int cypress_set_absolute_mode(struct psmouse *psmouse)
338 {
339 	struct cytp_data *cytp = psmouse->private;
340 	unsigned char param[3];
341 
342 	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_ABS_WITH_PRESSURE_MODE, param) < 0)
343 		return -1;
344 
345 	cytp->mode = (cytp->mode & ~CYTP_BIT_ABS_REL_MASK)
346 			| CYTP_BIT_ABS_PRESSURE;
347 	cypress_set_packet_size(psmouse, 5);
348 
349 	return 0;
350 }
351 
352 /*
353  * Reset trackpad device.
354  * This is also the default mode when trackpad powered on.
355  */
356 static void cypress_reset(struct psmouse *psmouse)
357 {
358 	struct cytp_data *cytp = psmouse->private;
359 
360 	cytp->mode = 0;
361 
362 	psmouse_reset(psmouse);
363 }
364 
365 static int cypress_set_input_params(struct input_dev *input,
366 				    struct cytp_data *cytp)
367 {
368 	int ret;
369 
370 	if (!cytp->tp_res_x || !cytp->tp_res_y)
371 		return -EINVAL;
372 
373 	__set_bit(EV_ABS, input->evbit);
374 	input_set_abs_params(input, ABS_X, 0, cytp->tp_max_abs_x, 0, 0);
375 	input_set_abs_params(input, ABS_Y, 0, cytp->tp_max_abs_y, 0, 0);
376 	input_set_abs_params(input, ABS_PRESSURE,
377 			     cytp->tp_min_pressure, cytp->tp_max_pressure, 0, 0);
378 	input_set_abs_params(input, ABS_TOOL_WIDTH, 0, 255, 0, 0);
379 
380 	/* finger position */
381 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, cytp->tp_max_abs_x, 0, 0);
382 	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, cytp->tp_max_abs_y, 0, 0);
383 	input_set_abs_params(input, ABS_MT_PRESSURE, 0, 255, 0, 0);
384 
385 	ret = input_mt_init_slots(input, CYTP_MAX_MT_SLOTS,
386 			INPUT_MT_DROP_UNUSED|INPUT_MT_TRACK);
387 	if (ret < 0)
388 		return ret;
389 
390 	__set_bit(INPUT_PROP_SEMI_MT, input->propbit);
391 
392 	input_abs_set_res(input, ABS_X, cytp->tp_res_x);
393 	input_abs_set_res(input, ABS_Y, cytp->tp_res_y);
394 
395 	input_abs_set_res(input, ABS_MT_POSITION_X, cytp->tp_res_x);
396 	input_abs_set_res(input, ABS_MT_POSITION_Y, cytp->tp_res_y);
397 
398 	__set_bit(BTN_TOUCH, input->keybit);
399 	__set_bit(BTN_TOOL_FINGER, input->keybit);
400 	__set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
401 	__set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
402 	__set_bit(BTN_TOOL_QUADTAP, input->keybit);
403 	__set_bit(BTN_TOOL_QUINTTAP, input->keybit);
404 
405 	__clear_bit(EV_REL, input->evbit);
406 	__clear_bit(REL_X, input->relbit);
407 	__clear_bit(REL_Y, input->relbit);
408 
409 	__set_bit(EV_KEY, input->evbit);
410 	__set_bit(BTN_LEFT, input->keybit);
411 	__set_bit(BTN_RIGHT, input->keybit);
412 	__set_bit(BTN_MIDDLE, input->keybit);
413 
414 	return 0;
415 }
416 
417 static int cypress_get_finger_count(unsigned char header_byte)
418 {
419 	unsigned char bits6_7;
420 	int finger_count;
421 
422 	bits6_7 = header_byte >> 6;
423 	finger_count = bits6_7 & 0x03;
424 
425 	if (finger_count == 1)
426 		return 1;
427 
428 	if (header_byte & ABS_HSCROLL_BIT) {
429 		/* HSCROLL gets added on to 0 finger count. */
430 		switch (finger_count) {
431 			case 0:	return 4;
432 			case 2: return 5;
433 			default:
434 				/* Invalid contact (e.g. palm). Ignore it. */
435 				return 0;
436 		}
437 	}
438 
439 	return finger_count;
440 }
441 
442 
443 static int cypress_parse_packet(struct psmouse *psmouse,
444 				struct cytp_data *cytp, struct cytp_report_data *report_data)
445 {
446 	unsigned char *packet = psmouse->packet;
447 	unsigned char header_byte = packet[0];
448 
449 	memset(report_data, 0, sizeof(struct cytp_report_data));
450 
451 	report_data->contact_cnt = cypress_get_finger_count(header_byte);
452 	report_data->tap = (header_byte & ABS_MULTIFINGER_TAP) ? 1 : 0;
453 
454 	if (report_data->contact_cnt == 1) {
455 		report_data->contacts[0].x =
456 			((packet[1] & 0x70) << 4) | packet[2];
457 		report_data->contacts[0].y =
458 			((packet[1] & 0x07) << 8) | packet[3];
459 		if (cytp->mode & CYTP_BIT_ABS_PRESSURE)
460 			report_data->contacts[0].z = packet[4];
461 
462 	} else if (report_data->contact_cnt >= 2) {
463 		report_data->contacts[0].x =
464 			((packet[1] & 0x70) << 4) | packet[2];
465 		report_data->contacts[0].y =
466 			((packet[1] & 0x07) << 8) | packet[3];
467 		if (cytp->mode & CYTP_BIT_ABS_PRESSURE)
468 			report_data->contacts[0].z = packet[4];
469 
470 		report_data->contacts[1].x =
471 			((packet[5] & 0xf0) << 4) | packet[6];
472 		report_data->contacts[1].y =
473 			((packet[5] & 0x0f) << 8) | packet[7];
474 		if (cytp->mode & CYTP_BIT_ABS_PRESSURE)
475 			report_data->contacts[1].z = report_data->contacts[0].z;
476 	}
477 
478 	report_data->left = (header_byte & BTN_LEFT_BIT) ? 1 : 0;
479 	report_data->right = (header_byte & BTN_RIGHT_BIT) ? 1 : 0;
480 
481 	/*
482 	 * This is only true if one of the mouse buttons were tapped.  Make
483 	 * sure it doesn't turn into a click. The regular tap-to-click
484 	 * functionality will handle that on its own. If we don't do this,
485 	 * disabling tap-to-click won't affect the mouse button zones.
486 	 */
487 	if (report_data->tap)
488 		report_data->left = 0;
489 
490 #ifdef CYTP_DEBUG_VERBOSE
491 	{
492 		int i;
493 		int n = report_data->contact_cnt;
494 		psmouse_dbg(psmouse, "Dump parsed report data as below:\n");
495 		psmouse_dbg(psmouse, "contact_cnt = %d\n",
496 			report_data->contact_cnt);
497 		if (n > CYTP_MAX_MT_SLOTS)
498 		    n = CYTP_MAX_MT_SLOTS;
499 		for (i = 0; i < n; i++)
500 			psmouse_dbg(psmouse, "contacts[%d] = {%d, %d, %d}\n", i,
501 					report_data->contacts[i].x,
502 					report_data->contacts[i].y,
503 					report_data->contacts[i].z);
504 		psmouse_dbg(psmouse, "left = %d\n", report_data->left);
505 		psmouse_dbg(psmouse, "right = %d\n", report_data->right);
506 		psmouse_dbg(psmouse, "middle = %d\n", report_data->middle);
507 	}
508 #endif
509 
510 	return 0;
511 }
512 
513 static void cypress_process_packet(struct psmouse *psmouse, bool zero_pkt)
514 {
515 	int i;
516 	struct input_dev *input = psmouse->dev;
517 	struct cytp_data *cytp = psmouse->private;
518 	struct cytp_report_data report_data;
519 	struct cytp_contact *contact;
520 	struct input_mt_pos pos[CYTP_MAX_MT_SLOTS];
521 	int slots[CYTP_MAX_MT_SLOTS];
522 	int n;
523 
524 	cypress_parse_packet(psmouse, cytp, &report_data);
525 
526 	n = report_data.contact_cnt;
527 	if (n > CYTP_MAX_MT_SLOTS)
528 		n = CYTP_MAX_MT_SLOTS;
529 
530 	for (i = 0; i < n; i++) {
531 		contact = &report_data.contacts[i];
532 		pos[i].x = contact->x;
533 		pos[i].y = contact->y;
534 	}
535 
536 	input_mt_assign_slots(input, slots, pos, n, 0);
537 
538 	for (i = 0; i < n; i++) {
539 		contact = &report_data.contacts[i];
540 		input_mt_slot(input, slots[i]);
541 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
542 		input_report_abs(input, ABS_MT_POSITION_X, contact->x);
543 		input_report_abs(input, ABS_MT_POSITION_Y, contact->y);
544 		input_report_abs(input, ABS_MT_PRESSURE, contact->z);
545 	}
546 
547 	input_mt_sync_frame(input);
548 
549 	input_mt_report_finger_count(input, report_data.contact_cnt);
550 
551 	input_report_key(input, BTN_LEFT, report_data.left);
552 	input_report_key(input, BTN_RIGHT, report_data.right);
553 	input_report_key(input, BTN_MIDDLE, report_data.middle);
554 
555 	input_sync(input);
556 }
557 
558 static psmouse_ret_t cypress_validate_byte(struct psmouse *psmouse)
559 {
560 	int contact_cnt;
561 	int index = psmouse->pktcnt - 1;
562 	unsigned char *packet = psmouse->packet;
563 	struct cytp_data *cytp = psmouse->private;
564 
565 	if (index < 0 || index > cytp->pkt_size)
566 		return PSMOUSE_BAD_DATA;
567 
568 	if (index == 0 && (packet[0] & 0xfc) == 0) {
569 		/* call packet process for reporting finger leave. */
570 		cypress_process_packet(psmouse, 1);
571 		return PSMOUSE_FULL_PACKET;
572 	}
573 
574 	/*
575 	 * Perform validation (and adjust packet size) based only on the
576 	 * first byte; allow all further bytes through.
577 	 */
578 	if (index != 0)
579 		return PSMOUSE_GOOD_DATA;
580 
581 	/*
582 	 * If absolute/relative mode bit has not been set yet, just pass
583 	 * the byte through.
584 	 */
585 	if ((cytp->mode & CYTP_BIT_ABS_REL_MASK) == 0)
586 		return PSMOUSE_GOOD_DATA;
587 
588 	if ((packet[0] & 0x08) == 0x08)
589 		return PSMOUSE_BAD_DATA;
590 
591 	contact_cnt = cypress_get_finger_count(packet[0]);
592 	if (cytp->mode & CYTP_BIT_ABS_NO_PRESSURE)
593 		cypress_set_packet_size(psmouse, contact_cnt == 2 ? 7 : 4);
594 	else
595 		cypress_set_packet_size(psmouse, contact_cnt == 2 ? 8 : 5);
596 
597 	return PSMOUSE_GOOD_DATA;
598 }
599 
600 static psmouse_ret_t cypress_protocol_handler(struct psmouse *psmouse)
601 {
602 	struct cytp_data *cytp = psmouse->private;
603 
604 	if (psmouse->pktcnt >= cytp->pkt_size) {
605 		cypress_process_packet(psmouse, 0);
606 		return PSMOUSE_FULL_PACKET;
607 	}
608 
609 	return cypress_validate_byte(psmouse);
610 }
611 
612 static void cypress_set_rate(struct psmouse *psmouse, unsigned int rate)
613 {
614 	struct cytp_data *cytp = psmouse->private;
615 
616 	if (rate >= 80) {
617 		psmouse->rate = 80;
618 		cytp->mode |= CYTP_BIT_HIGH_RATE;
619 	} else {
620 		psmouse->rate = 40;
621 		cytp->mode &= ~CYTP_BIT_HIGH_RATE;
622 	}
623 
624 	ps2_command(&psmouse->ps2dev, (unsigned char *)&psmouse->rate,
625 		    PSMOUSE_CMD_SETRATE);
626 }
627 
628 static void cypress_disconnect(struct psmouse *psmouse)
629 {
630 	cypress_reset(psmouse);
631 	kfree(psmouse->private);
632 	psmouse->private = NULL;
633 }
634 
635 static int cypress_reconnect(struct psmouse *psmouse)
636 {
637 	int tries = CYTP_PS2_CMD_TRIES;
638 	int rc;
639 
640 	do {
641 		cypress_reset(psmouse);
642 		rc = cypress_detect(psmouse, false);
643 	} while (rc && (--tries > 0));
644 
645 	if (rc) {
646 		psmouse_err(psmouse, "Reconnect: unable to detect trackpad.\n");
647 		return -1;
648 	}
649 
650 	if (cypress_set_absolute_mode(psmouse)) {
651 		psmouse_err(psmouse, "Reconnect: Unable to initialize Cypress absolute mode.\n");
652 		return -1;
653 	}
654 
655 	return 0;
656 }
657 
658 int cypress_init(struct psmouse *psmouse)
659 {
660 	struct cytp_data *cytp;
661 
662 	cytp = kzalloc(sizeof(struct cytp_data), GFP_KERNEL);
663 	if (!cytp)
664 		return -ENOMEM;
665 
666 	psmouse->private = cytp;
667 	psmouse->pktsize = 8;
668 
669 	cypress_reset(psmouse);
670 
671 	if (cypress_query_hardware(psmouse)) {
672 		psmouse_err(psmouse, "Unable to query Trackpad hardware.\n");
673 		goto err_exit;
674 	}
675 
676 	if (cypress_set_absolute_mode(psmouse)) {
677 		psmouse_err(psmouse, "init: Unable to initialize Cypress absolute mode.\n");
678 		goto err_exit;
679 	}
680 
681 	if (cypress_set_input_params(psmouse->dev, cytp) < 0) {
682 		psmouse_err(psmouse, "init: Unable to set input params.\n");
683 		goto err_exit;
684 	}
685 
686 	psmouse->model = 1;
687 	psmouse->protocol_handler = cypress_protocol_handler;
688 	psmouse->set_rate = cypress_set_rate;
689 	psmouse->disconnect = cypress_disconnect;
690 	psmouse->reconnect = cypress_reconnect;
691 	psmouse->cleanup = cypress_reset;
692 	psmouse->resync_time = 0;
693 
694 	return 0;
695 
696 err_exit:
697 	/*
698 	 * Reset Cypress Trackpad as a standard mouse. Then
699 	 * let psmouse driver commmunicating with it as default PS2 mouse.
700 	 */
701 	cypress_reset(psmouse);
702 
703 	psmouse->private = NULL;
704 	kfree(cytp);
705 
706 	return -1;
707 }
708