swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 62fb9874f5da54fdb243003b386128037319b219 authored by Linus Torvalds on 27 June 2021, 22:21:11 UTC
Linux 5.13
Linux 5.13
Tip revision: 62fb987
cypress_ps2.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
*/
#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(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(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;
/*
* Trackpad fw_version 11 (in Dell XPS12) yields a bogus response to
* CYTP_CMD_READ_TP_METRICS so do not try to use it. LP: #1103594.
*/
if (cytp->fw_version >= 11)
cytp->tp_metrics_supported = 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;
if (!cytp->tp_metrics_supported)
return 0;
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)
{
int ret;
ret = cypress_read_fw_version(psmouse);
if (ret)
return ret;
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(EV_KEY, input->evbit);
__set_bit(BTN_LEFT, input->keybit);
__set_bit(BTN_RIGHT, input->keybit);
__set_bit(BTN_MIDDLE, input->keybit);
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 0;
}
}
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];
memset(report_data, 0, sizeof(struct cytp_report_data));
report_data->contact_cnt = cypress_get_finger_count(header_byte);
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;
cypress_parse_packet(psmouse, cytp, &report_data);
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, 0);
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 (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 = kzalloc(sizeof(struct cytp_data), GFP_KERNEL);
if (!cytp)
return -ENOMEM;
psmouse->private = cytp;
psmouse->pktsize = 8;
cypress_reset(psmouse);
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;
}