Input: add support for Cypress PS/2 Trackpads

This driver, submitted on behalf of Cypress Semiconductor Corporation and
additional contributors, provides support for the Cypress PS/2 Trackpad.

Original code contributed by Dudley Du (Cypress Semiconductor Corporation),
modified by Kamal Mostafa and Kyle Fazzari.

BugLink: http://launchpad.net/bugs/978807

Signed-off-by: Dudley Du <dudl@cypress.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kyle Fazzari <git@status.e4ward.com>
Signed-off-by: Mario Limonciello <mario_limonciello@dell.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Herton Krzesinski <herton.krzesinski@canonical.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Reviewed-by: Dudley Du <dudl@cypress.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 725 insertions, 0 deletions

diff --git a/drivers/input/mouse/cypress_ps2.c b/drivers/input/mouse/cypress_ps2.c
new file mode 100644
index 000000000000..1673dc6c8092
--- /dev/null
+++ b/drivers/input/mouse/cypress_ps2.c
@@ -0,0 +1,725 @@
+/*
+ * Cypress Trackpad PS/2 mouse driver
+ *
+ * Copyright (c) 2012 Cypress Semiconductor Corporation.
+ *
+ * Author:
+ *   Dudley Du <dudl@cypress.com>
+ *
+ * Additional contributors include:
+ *   Kamal Mostafa <kamal@canonical.com>
+ *   Kyle Fazzari <git@status.e4ward.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/serio.h>
+#include <linux/libps2.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#include "cypress_ps2.h"
+
+#undef CYTP_DEBUG_VERBOSE  /* define this and DEBUG for more verbose dump */
+
+static void cypress_set_packet_size(struct psmouse *psmouse, unsigned int n)
+{
+	struct cytp_data *cytp = psmouse->private;
+	cytp->pkt_size = n;
+}
+
+static const unsigned char cytp_rate[] = {10, 20, 40, 60, 100, 200};
+static const unsigned char cytp_resolution[] = {0x00, 0x01, 0x02, 0x03};
+
+static int cypress_ps2_sendbyte(struct psmouse *psmouse, int value)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+
+	if (ps2_sendbyte(ps2dev, value & 0xff, CYTP_CMD_TIMEOUT) < 0) {
+		psmouse_dbg(psmouse,
+				"sending command 0x%02x failed, resp 0x%02x\n",
+				value & 0xff, ps2dev->nak);
+		if (ps2dev->nak == CYTP_PS2_RETRY)
+			return CYTP_PS2_RETRY;
+		else
+			return CYTP_PS2_ERROR;
+	}
+
+#ifdef CYTP_DEBUG_VERBOSE
+	psmouse_dbg(psmouse, "sending command 0x%02x succeeded, resp 0xfa\n",
+			value & 0xff);
+#endif
+
+	return 0;
+}
+
+static int cypress_ps2_ext_cmd(struct psmouse *psmouse, unsigned short cmd,
+			       unsigned char data)
+{
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	int tries = CYTP_PS2_CMD_TRIES;
+	int rc;
+
+	ps2_begin_command(ps2dev);
+
+	do {
+		/*
+		 * Send extension command byte (0xE8 or 0xF3).
+		 * If sending the command fails, send recovery command
+		 * to make the device return to the ready state.
+		 */
+		rc = cypress_ps2_sendbyte(psmouse, cmd & 0xff);
+		if (rc == CYTP_PS2_RETRY) {
+			rc = cypress_ps2_sendbyte(psmouse, 0x00);
+			if (rc == CYTP_PS2_RETRY)
+				rc = cypress_ps2_sendbyte(psmouse, 0x0a);
+		}
+		if (rc == CYTP_PS2_ERROR)
+			continue;
+
+		rc = cypress_ps2_sendbyte(psmouse, data);
+		if (rc == CYTP_PS2_RETRY)
+			rc = cypress_ps2_sendbyte(psmouse, data);
+		if (rc == CYTP_PS2_ERROR)
+			continue;
+		else
+			break;
+	} while (--tries > 0);
+
+	ps2_end_command(ps2dev);
+
+	return rc;
+}
+
+static int cypress_ps2_read_cmd_status(struct psmouse *psmouse,
+				       unsigned char cmd,
+				       unsigned char *param)
+{
+	int rc;
+	struct ps2dev *ps2dev = &psmouse->ps2dev;
+	enum psmouse_state old_state;
+	int pktsize;
+
+	ps2_begin_command(&psmouse->ps2dev);
+
+	old_state = psmouse->state;
+	psmouse->state = PSMOUSE_CMD_MODE;
+	psmouse->pktcnt = 0;
+
+	pktsize = (cmd == CYTP_CMD_READ_TP_METRICS) ? 8 : 3;
+	memset(param, 0, pktsize);
+
+	rc = cypress_ps2_sendbyte(psmouse, 0xe9);
+	if (rc < 0)
+		goto out;
+
+	wait_event_timeout(ps2dev->wait,
+			(psmouse->pktcnt >= pktsize),
+			msecs_to_jiffies(CYTP_CMD_TIMEOUT));
+
+	memcpy(param, psmouse->packet, pktsize);
+
+	psmouse_dbg(psmouse, "Command 0x%02x response data (0x): %*ph\n",
+			cmd, pktsize, param);
+
+out:
+	psmouse->state = old_state;
+	psmouse->pktcnt = 0;
+
+	ps2_end_command(&psmouse->ps2dev);
+
+	return rc;
+}
+
+static bool cypress_verify_cmd_state(struct psmouse *psmouse,
+				     unsigned char cmd, unsigned char *param)
+{
+	bool rate_match = false;
+	bool resolution_match = false;
+	int i;
+
+	/* callers will do further checking. */
+	if (cmd == CYTP_CMD_READ_CYPRESS_ID ||
+	    cmd == CYTP_CMD_STANDARD_MODE ||
+	    cmd == CYTP_CMD_READ_TP_METRICS)
+		return true;
+
+	if ((~param[0] & DFLT_RESP_BITS_VALID) == DFLT_RESP_BITS_VALID &&
+	    (param[0] & DFLT_RESP_BIT_MODE) == DFLT_RESP_STREAM_MODE) {
+		for (i = 0; i < sizeof(cytp_resolution); i++)
+			if (cytp_resolution[i] == param[1])
+				resolution_match = true;
+
+		for (i = 0; i < sizeof(cytp_rate); i++)
+			if (cytp_rate[i] == param[2])
+				rate_match = true;
+
+		if (resolution_match && rate_match)
+			return true;
+	}
+
+	psmouse_dbg(psmouse, "verify cmd state failed.\n");
+	return false;
+}
+
+static int cypress_send_ext_cmd(struct psmouse *psmouse, unsigned char cmd,
+				unsigned char *param)
+{
+	int tries = CYTP_PS2_CMD_TRIES;
+	int rc;
+
+	psmouse_dbg(psmouse, "send extension cmd 0x%02x, [%d %d %d %d]\n",
+		 cmd, DECODE_CMD_AA(cmd), DECODE_CMD_BB(cmd),
+		 DECODE_CMD_CC(cmd), DECODE_CMD_DD(cmd));
+
+	do {
+		cypress_ps2_ext_cmd(psmouse,
+				    PSMOUSE_CMD_SETRES, DECODE_CMD_DD(cmd));
+		cypress_ps2_ext_cmd(psmouse,
+				    PSMOUSE_CMD_SETRES, DECODE_CMD_CC(cmd));
+		cypress_ps2_ext_cmd(psmouse,
+				    PSMOUSE_CMD_SETRES, DECODE_CMD_BB(cmd));
+		cypress_ps2_ext_cmd(psmouse,
+				    PSMOUSE_CMD_SETRES, DECODE_CMD_AA(cmd));
+
+		rc = cypress_ps2_read_cmd_status(psmouse, cmd, param);
+		if (rc)
+			continue;
+
+		if (cypress_verify_cmd_state(psmouse, cmd, param))
+			return 0;
+
+	} while (--tries > 0);
+
+	return -EIO;
+}
+
+int cypress_detect(struct psmouse *psmouse, bool set_properties)
+{
+	unsigned char param[3];
+
+	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_READ_CYPRESS_ID, param))
+		return -ENODEV;
+
+	/* Check for Cypress Trackpad signature bytes: 0x33 0xCC */
+	if (param[0] != 0x33 || param[1] != 0xCC)
+		return -ENODEV;
+
+	if (set_properties) {
+		psmouse->vendor = "Cypress";
+		psmouse->name = "Trackpad";
+	}
+
+	return 0;
+}
+
+static int cypress_read_fw_version(struct psmouse *psmouse)
+{
+	struct cytp_data *cytp = psmouse->private;
+	unsigned char param[3];
+
+	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_READ_CYPRESS_ID, param))
+		return -ENODEV;
+
+	/* Check for Cypress Trackpad signature bytes: 0x33 0xCC */
+	if (param[0] != 0x33 || param[1] != 0xCC)
+		return -ENODEV;
+
+	cytp->fw_version = param[2] & FW_VERSION_MASX;
+	cytp->tp_metrics_supported = (param[2] & TP_METRICS_MASK) ? 1 : 0;
+
+	psmouse_dbg(psmouse, "cytp->fw_version = %d\n", cytp->fw_version);
+	psmouse_dbg(psmouse, "cytp->tp_metrics_supported = %d\n",
+		 cytp->tp_metrics_supported);
+
+	return 0;
+}
+
+static int cypress_read_tp_metrics(struct psmouse *psmouse)
+{
+	struct cytp_data *cytp = psmouse->private;
+	unsigned char param[8];
+
+	/* set default values for tp metrics. */
+	cytp->tp_width = CYTP_DEFAULT_WIDTH;
+	cytp->tp_high = CYTP_DEFAULT_HIGH;
+	cytp->tp_max_abs_x = CYTP_ABS_MAX_X;
+	cytp->tp_max_abs_y = CYTP_ABS_MAX_Y;
+	cytp->tp_min_pressure = CYTP_MIN_PRESSURE;
+	cytp->tp_max_pressure = CYTP_MAX_PRESSURE;
+	cytp->tp_res_x = cytp->tp_max_abs_x / cytp->tp_width;
+	cytp->tp_res_y = cytp->tp_max_abs_y / cytp->tp_high;
+
+	memset(param, 0, sizeof(param));
+	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_READ_TP_METRICS, param) == 0) {
+		/* Update trackpad parameters. */
+		cytp->tp_max_abs_x = (param[1] << 8) | param[0];
+		cytp->tp_max_abs_y = (param[3] << 8) | param[2];
+		cytp->tp_min_pressure = param[4];
+		cytp->tp_max_pressure = param[5];
+	}
+
+	if (!cytp->tp_max_pressure ||
+	    cytp->tp_max_pressure < cytp->tp_min_pressure ||
+	    !cytp->tp_width || !cytp->tp_high ||
+	    !cytp->tp_max_abs_x ||
+	    cytp->tp_max_abs_x < cytp->tp_width ||
+	    !cytp->tp_max_abs_y ||
+	    cytp->tp_max_abs_y < cytp->tp_high)
+		return -EINVAL;
+
+	cytp->tp_res_x = cytp->tp_max_abs_x / cytp->tp_width;
+	cytp->tp_res_y = cytp->tp_max_abs_y / cytp->tp_high;
+
+#ifdef CYTP_DEBUG_VERBOSE
+	psmouse_dbg(psmouse, "Dump trackpad hardware configuration as below:\n");
+	psmouse_dbg(psmouse, "cytp->tp_width = %d\n", cytp->tp_width);
+	psmouse_dbg(psmouse, "cytp->tp_high = %d\n", cytp->tp_high);
+	psmouse_dbg(psmouse, "cytp->tp_max_abs_x = %d\n", cytp->tp_max_abs_x);
+	psmouse_dbg(psmouse, "cytp->tp_max_abs_y = %d\n", cytp->tp_max_abs_y);
+	psmouse_dbg(psmouse, "cytp->tp_min_pressure = %d\n", cytp->tp_min_pressure);
+	psmouse_dbg(psmouse, "cytp->tp_max_pressure = %d\n", cytp->tp_max_pressure);
+	psmouse_dbg(psmouse, "cytp->tp_res_x = %d\n", cytp->tp_res_x);
+	psmouse_dbg(psmouse, "cytp->tp_res_y = %d\n", cytp->tp_res_y);
+
+	psmouse_dbg(psmouse, "tp_type_APA = %d\n",
+			(param[6] & TP_METRICS_BIT_APA) ? 1 : 0);
+	psmouse_dbg(psmouse, "tp_type_MTG = %d\n",
+			(param[6] & TP_METRICS_BIT_MTG) ? 1 : 0);
+	psmouse_dbg(psmouse, "tp_palm = %d\n",
+			(param[6] & TP_METRICS_BIT_PALM) ? 1 : 0);
+	psmouse_dbg(psmouse, "tp_stubborn = %d\n",
+			(param[6] & TP_METRICS_BIT_STUBBORN) ? 1 : 0);
+	psmouse_dbg(psmouse, "tp_1f_jitter = %d\n",
+			(param[6] & TP_METRICS_BIT_1F_JITTER) >> 2);
+	psmouse_dbg(psmouse, "tp_2f_jitter = %d\n",
+			(param[6] & TP_METRICS_BIT_2F_JITTER) >> 4);
+	psmouse_dbg(psmouse, "tp_1f_spike = %d\n",
+			param[7] & TP_METRICS_BIT_1F_SPIKE);
+	psmouse_dbg(psmouse, "tp_2f_spike = %d\n",
+			(param[7] & TP_METRICS_BIT_2F_SPIKE) >> 2);
+	psmouse_dbg(psmouse, "tp_abs_packet_format_set = %d\n",
+			(param[7] & TP_METRICS_BIT_ABS_PKT_FORMAT_SET) >> 4);
+#endif
+
+	return 0;
+}
+
+static int cypress_query_hardware(struct psmouse *psmouse)
+{
+	struct cytp_data *cytp = psmouse->private;
+	int ret;
+
+	ret = cypress_read_fw_version(psmouse);
+	if (ret)
+		return ret;
+
+	if (cytp->tp_metrics_supported) {
+		ret = cypress_read_tp_metrics(psmouse);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int cypress_set_absolute_mode(struct psmouse *psmouse)
+{
+	struct cytp_data *cytp = psmouse->private;
+	unsigned char param[3];
+
+	if (cypress_send_ext_cmd(psmouse, CYTP_CMD_ABS_WITH_PRESSURE_MODE, param) < 0)
+		return -1;
+
+	cytp->mode = (cytp->mode & ~CYTP_BIT_ABS_REL_MASK)
+			| CYTP_BIT_ABS_PRESSURE;
+	cypress_set_packet_size(psmouse, 5);
+
+	return 0;
+}
+
+/*
+ * Reset trackpad device.
+ * This is also the default mode when trackpad powered on.
+ */
+static void cypress_reset(struct psmouse *psmouse)
+{
+	struct cytp_data *cytp = psmouse->private;
+
+	cytp->mode = 0;
+
+	psmouse_reset(psmouse);
+}
+
+static int cypress_set_input_params(struct input_dev *input,
+				    struct cytp_data *cytp)
+{
+	int ret;
+
+	if (!cytp->tp_res_x || !cytp->tp_res_y)
+		return -EINVAL;
+
+	__set_bit(EV_ABS, input->evbit);
+	input_set_abs_params(input, ABS_X, 0, cytp->tp_max_abs_x, 0, 0);
+	input_set_abs_params(input, ABS_Y, 0, cytp->tp_max_abs_y, 0, 0);
+	input_set_abs_params(input, ABS_PRESSURE,
+			     cytp->tp_min_pressure, cytp->tp_max_pressure, 0, 0);
+	input_set_abs_params(input, ABS_TOOL_WIDTH, 0, 255, 0, 0);
+
+	/* finger position */
+	input_set_abs_params(input, ABS_MT_POSITION_X, 0, cytp->tp_max_abs_x, 0, 0);
+	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, cytp->tp_max_abs_y, 0, 0);
+	input_set_abs_params(input, ABS_MT_PRESSURE, 0, 255, 0, 0);
+
+	ret = input_mt_init_slots(input, CYTP_MAX_MT_SLOTS,
+			INPUT_MT_DROP_UNUSED|INPUT_MT_TRACK);
+	if (ret < 0)
+		return ret;
+
+	__set_bit(INPUT_PROP_SEMI_MT, input->propbit);
+
+	input_abs_set_res(input, ABS_X, cytp->tp_res_x);
+	input_abs_set_res(input, ABS_Y, cytp->tp_res_y);
+
+	input_abs_set_res(input, ABS_MT_POSITION_X, cytp->tp_res_x);
+	input_abs_set_res(input, ABS_MT_POSITION_Y, cytp->tp_res_y);
+
+	__set_bit(BTN_TOUCH, input->keybit);
+	__set_bit(BTN_TOOL_FINGER, input->keybit);
+	__set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
+	__set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
+	__set_bit(BTN_TOOL_QUADTAP, input->keybit);
+	__set_bit(BTN_TOOL_QUINTTAP, input->keybit);
+
+	__clear_bit(EV_REL, input->evbit);
+	__clear_bit(REL_X, input->relbit);
+	__clear_bit(REL_Y, input->relbit);
+
+	__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(BTN_LEFT, input->keybit);
+	__set_bit(BTN_RIGHT, input->keybit);
+	__set_bit(BTN_MIDDLE, input->keybit);
+
+	input_set_drvdata(input, cytp);
+
+	return 0;
+}
+
+static int cypress_get_finger_count(unsigned char header_byte)
+{
+	unsigned char bits6_7;
+	int finger_count;
+
+	bits6_7 = header_byte >> 6;
+	finger_count = bits6_7 & 0x03;
+
+	if (finger_count == 1)
+		return 1;
+
+	if (header_byte & ABS_HSCROLL_BIT) {
+		/* HSCROLL gets added on to 0 finger count. */
+		switch (finger_count) {
+			case 0:	return 4;
+			case 2: return 5;
+			default:
+				/* Invalid contact (e.g. palm). Ignore it. */
+				return -1;
+		}
+	}
+
+	return finger_count;
+}
+
+
+static int cypress_parse_packet(struct psmouse *psmouse,
+				struct cytp_data *cytp, struct cytp_report_data *report_data)
+{
+	unsigned char *packet = psmouse->packet;
+	unsigned char header_byte = packet[0];
+	int contact_cnt;
+
+	memset(report_data, 0, sizeof(struct cytp_report_data));
+
+	contact_cnt = cypress_get_finger_count(header_byte);
+
+	if (contact_cnt < 0) /* e.g. palm detect */
+		return -EINVAL;
+
+	report_data->contact_cnt = contact_cnt;
+
+	report_data->tap = (header_byte & ABS_MULTIFINGER_TAP) ? 1 : 0;
+
+	if (report_data->contact_cnt == 1) {
+		report_data->contacts[0].x =
+			((packet[1] & 0x70) << 4) | packet[2];
+		report_data->contacts[0].y =
+			((packet[1] & 0x07) << 8) | packet[3];
+		if (cytp->mode & CYTP_BIT_ABS_PRESSURE)
+			report_data->contacts[0].z = packet[4];
+
+	} else if (report_data->contact_cnt >= 2) {
+		report_data->contacts[0].x =
+			((packet[1] & 0x70) << 4) | packet[2];
+		report_data->contacts[0].y =
+			((packet[1] & 0x07) << 8) | packet[3];
+		if (cytp->mode & CYTP_BIT_ABS_PRESSURE)
+			report_data->contacts[0].z = packet[4];
+
+		report_data->contacts[1].x =
+			((packet[5] & 0xf0) << 4) | packet[6];
+		report_data->contacts[1].y =
+			((packet[5] & 0x0f) << 8) | packet[7];
+		if (cytp->mode & CYTP_BIT_ABS_PRESSURE)
+			report_data->contacts[1].z = report_data->contacts[0].z;
+	}
+
+	report_data->left = (header_byte & BTN_LEFT_BIT) ? 1 : 0;
+	report_data->right = (header_byte & BTN_RIGHT_BIT) ? 1 : 0;
+
+	/*
+	 * This is only true if one of the mouse buttons were tapped.  Make
+	 * sure it doesn't turn into a click. The regular tap-to-click
+	 * functionality will handle that on its own. If we don't do this,
+	 * disabling tap-to-click won't affect the mouse button zones.
+	 */
+	if (report_data->tap)
+		report_data->left = 0;
+
+#ifdef CYTP_DEBUG_VERBOSE
+	{
+		int i;
+		int n = report_data->contact_cnt;
+		psmouse_dbg(psmouse, "Dump parsed report data as below:\n");
+		psmouse_dbg(psmouse, "contact_cnt = %d\n",
+			report_data->contact_cnt);
+		if (n > CYTP_MAX_MT_SLOTS)
+		    n = CYTP_MAX_MT_SLOTS;
+		for (i = 0; i < n; i++)
+			psmouse_dbg(psmouse, "contacts[%d] = {%d, %d, %d}\n", i,
+					report_data->contacts[i].x,
+					report_data->contacts[i].y,
+					report_data->contacts[i].z);
+		psmouse_dbg(psmouse, "left = %d\n", report_data->left);
+		psmouse_dbg(psmouse, "right = %d\n", report_data->right);
+		psmouse_dbg(psmouse, "middle = %d\n", report_data->middle);
+	}
+#endif
+
+	return 0;
+}
+
+static void cypress_process_packet(struct psmouse *psmouse, bool zero_pkt)
+{
+	int i;
+	struct input_dev *input = psmouse->dev;
+	struct cytp_data *cytp = psmouse->private;
+	struct cytp_report_data report_data;
+	struct cytp_contact *contact;
+	struct input_mt_pos pos[CYTP_MAX_MT_SLOTS];
+	int slots[CYTP_MAX_MT_SLOTS];
+	int n;
+
+	if (cypress_parse_packet(psmouse, cytp, &report_data))
+		return;
+
+	n = report_data.contact_cnt;
+
+	if (n > CYTP_MAX_MT_SLOTS)
+		n = CYTP_MAX_MT_SLOTS;
+
+	for (i = 0; i < n; i++) {
+		contact = &report_data.contacts[i];
+		pos[i].x = contact->x;
+		pos[i].y = contact->y;
+	}
+
+	input_mt_assign_slots(input, slots, pos, n);
+
+	for (i = 0; i < n; i++) {
+		contact = &report_data.contacts[i];
+		input_mt_slot(input, slots[i]);
+		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
+		input_report_abs(input, ABS_MT_POSITION_X, contact->x);
+		input_report_abs(input, ABS_MT_POSITION_Y, contact->y);
+		input_report_abs(input, ABS_MT_PRESSURE, contact->z);
+	}
+
+	input_mt_sync_frame(input);
+
+	input_mt_report_finger_count(input, report_data.contact_cnt);
+
+	input_report_key(input, BTN_LEFT, report_data.left);
+	input_report_key(input, BTN_RIGHT, report_data.right);
+	input_report_key(input, BTN_MIDDLE, report_data.middle);
+
+	input_sync(input);
+}
+
+static psmouse_ret_t cypress_validate_byte(struct psmouse *psmouse)
+{
+	int contact_cnt;
+	int index = psmouse->pktcnt - 1;
+	unsigned char *packet = psmouse->packet;
+	struct cytp_data *cytp = psmouse->private;
+
+	if (index < 0 || index > cytp->pkt_size)
+		return PSMOUSE_BAD_DATA;
+
+	if (index == 0 && (packet[0] & 0xfc) == 0) {
+		/* call packet process for reporting finger leave. */
+		cypress_process_packet(psmouse, 1);
+		return PSMOUSE_FULL_PACKET;
+	}
+
+	/*
+	 * Perform validation (and adjust packet size) based only on the
+	 * first byte; allow all further bytes through.
+	 */
+	if (index != 0)
+		return PSMOUSE_GOOD_DATA;
+
+	/*
+	 * If absolute/relative mode bit has not been set yet, just pass
+	 * the byte through.
+	 */
+	if ((cytp->mode & CYTP_BIT_ABS_REL_MASK) == 0)
+		return PSMOUSE_GOOD_DATA;
+
+	if ((packet[0] & 0x08) == 0x08)
+		return PSMOUSE_BAD_DATA;
+
+	contact_cnt = cypress_get_finger_count(packet[0]);
+
+	if (contact_cnt < 0)
+		return PSMOUSE_BAD_DATA;
+
+	if (cytp->mode & CYTP_BIT_ABS_NO_PRESSURE)
+		cypress_set_packet_size(psmouse, contact_cnt == 2 ? 7 : 4);
+	else
+		cypress_set_packet_size(psmouse, contact_cnt == 2 ? 8 : 5);
+
+	return PSMOUSE_GOOD_DATA;
+}
+
+static psmouse_ret_t cypress_protocol_handler(struct psmouse *psmouse)
+{
+	struct cytp_data *cytp = psmouse->private;
+
+	if (psmouse->pktcnt >= cytp->pkt_size) {
+		cypress_process_packet(psmouse, 0);
+		return PSMOUSE_FULL_PACKET;
+	}
+
+	return cypress_validate_byte(psmouse);
+}
+
+static void cypress_set_rate(struct psmouse *psmouse, unsigned int rate)
+{
+	struct cytp_data *cytp = psmouse->private;
+
+	if (rate >= 80) {
+		psmouse->rate = 80;
+		cytp->mode |= CYTP_BIT_HIGH_RATE;
+	} else {
+		psmouse->rate = 40;
+		cytp->mode &= ~CYTP_BIT_HIGH_RATE;
+	}
+
+	ps2_command(&psmouse->ps2dev, (unsigned char *)&psmouse->rate,
+		    PSMOUSE_CMD_SETRATE);
+}
+
+static void cypress_disconnect(struct psmouse *psmouse)
+{
+	cypress_reset(psmouse);
+	kfree(psmouse->private);
+	psmouse->private = NULL;
+}
+
+static int cypress_reconnect(struct psmouse *psmouse)
+{
+	int tries = CYTP_PS2_CMD_TRIES;
+	int rc;
+
+	do {
+		cypress_reset(psmouse);
+		rc = cypress_detect(psmouse, false);
+	} while (rc && (--tries > 0));
+
+	if (rc) {
+		psmouse_err(psmouse, "Reconnect: unable to detect trackpad.\n");
+		return -1;
+	}
+
+	if (cypress_set_absolute_mode(psmouse)) {
+		psmouse_err(psmouse, "Reconnect: Unable to initialize Cypress absolute mode.\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+int cypress_init(struct psmouse *psmouse)
+{
+	struct cytp_data *cytp;
+
+	cytp = (struct cytp_data *)kzalloc(sizeof(struct cytp_data), GFP_KERNEL);
+	psmouse->private = (void *)cytp;
+	if (cytp == NULL)
+		return -ENOMEM;
+
+	cypress_reset(psmouse);
+
+	psmouse->pktsize = 8;
+
+	if (cypress_query_hardware(psmouse)) {
+		psmouse_err(psmouse, "Unable to query Trackpad hardware.\n");
+		goto err_exit;
+	}
+
+	if (cypress_set_absolute_mode(psmouse)) {
+		psmouse_err(psmouse, "init: Unable to initialize Cypress absolute mode.\n");
+		goto err_exit;
+	}
+
+	if (cypress_set_input_params(psmouse->dev, cytp) < 0) {
+		psmouse_err(psmouse, "init: Unable to set input params.\n");
+		goto err_exit;
+	}
+
+	psmouse->model = 1;
+	psmouse->protocol_handler = cypress_protocol_handler;
+	psmouse->set_rate = cypress_set_rate;
+	psmouse->disconnect = cypress_disconnect;
+	psmouse->reconnect = cypress_reconnect;
+	psmouse->cleanup = cypress_reset;
+	psmouse->resync_time = 0;
+
+	return 0;
+
+err_exit:
+	/*
+	 * Reset Cypress Trackpad as a standard mouse. Then
+	 * let psmouse driver commmunicating with it as default PS2 mouse.
+	 */
+	cypress_reset(psmouse);
+
+	psmouse->private = NULL;
+	kfree(cytp);
+
+	return -1;
+}
+
+bool cypress_supported(void)
+{
+	return true;
+}