https://jxself.org/git/linux-libre.git
Tip revision: 8e7879b0951a8605403962ac8f3d7fa5df3fbfed authored by Jason Self on 13 July 2011, 03:31:57 UTC
Linux-libre 2.6.33.16-gnu1
Linux-libre 2.6.33.16-gnu1
Tip revision: 8e7879b
elantech.c
/*
* Elantech Touchpad driver (v6)
*
* Copyright (C) 2007-2009 Arjan Opmeer <arjan@opmeer.net>
*
* 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.
*
* Trademarks are the property of their respective owners.
*/
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/libps2.h>
#include "psmouse.h"
#include "elantech.h"
#define elantech_debug(format, arg...) \
do { \
if (etd->debug) \
printk(KERN_DEBUG format, ##arg); \
} while (0)
/*
* Send a Synaptics style sliced query command
*/
static int synaptics_send_cmd(struct psmouse *psmouse, unsigned char c,
unsigned char *param)
{
if (psmouse_sliced_command(psmouse, c) ||
ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
pr_err("elantech.c: synaptics_send_cmd query 0x%02x failed.\n", c);
return -1;
}
return 0;
}
/*
* A retrying version of ps2_command
*/
static int elantech_ps2_command(struct psmouse *psmouse,
unsigned char *param, int command)
{
struct ps2dev *ps2dev = &psmouse->ps2dev;
struct elantech_data *etd = psmouse->private;
int rc;
int tries = ETP_PS2_COMMAND_TRIES;
do {
rc = ps2_command(ps2dev, param, command);
if (rc == 0)
break;
tries--;
elantech_debug("elantech.c: retrying ps2 command 0x%02x (%d).\n",
command, tries);
msleep(ETP_PS2_COMMAND_DELAY);
} while (tries > 0);
if (rc)
pr_err("elantech.c: ps2 command 0x%02x failed.\n", command);
return rc;
}
/*
* Send an Elantech style special command to read a value from a register
*/
static int elantech_read_reg(struct psmouse *psmouse, unsigned char reg,
unsigned char *val)
{
struct elantech_data *etd = psmouse->private;
unsigned char param[3];
int rc = 0;
if (reg < 0x10 || reg > 0x26)
return -1;
if (reg > 0x11 && reg < 0x20)
return -1;
switch (etd->hw_version) {
case 1:
if (psmouse_sliced_command(psmouse, ETP_REGISTER_READ) ||
psmouse_sliced_command(psmouse, reg) ||
ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETINFO)) {
rc = -1;
}
break;
case 2:
if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
elantech_ps2_command(psmouse, NULL, ETP_REGISTER_READ) ||
elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
elantech_ps2_command(psmouse, NULL, reg) ||
elantech_ps2_command(psmouse, param, PSMOUSE_CMD_GETINFO)) {
rc = -1;
}
break;
}
if (rc)
pr_err("elantech.c: failed to read register 0x%02x.\n", reg);
else
*val = param[0];
return rc;
}
/*
* Send an Elantech style special command to write a register with a value
*/
static int elantech_write_reg(struct psmouse *psmouse, unsigned char reg,
unsigned char val)
{
struct elantech_data *etd = psmouse->private;
int rc = 0;
if (reg < 0x10 || reg > 0x26)
return -1;
if (reg > 0x11 && reg < 0x20)
return -1;
switch (etd->hw_version) {
case 1:
if (psmouse_sliced_command(psmouse, ETP_REGISTER_WRITE) ||
psmouse_sliced_command(psmouse, reg) ||
psmouse_sliced_command(psmouse, val) ||
ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11)) {
rc = -1;
}
break;
case 2:
if (elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
elantech_ps2_command(psmouse, NULL, ETP_REGISTER_WRITE) ||
elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
elantech_ps2_command(psmouse, NULL, reg) ||
elantech_ps2_command(psmouse, NULL, ETP_PS2_CUSTOM_COMMAND) ||
elantech_ps2_command(psmouse, NULL, val) ||
elantech_ps2_command(psmouse, NULL, PSMOUSE_CMD_SETSCALE11)) {
rc = -1;
}
break;
}
if (rc)
pr_err("elantech.c: failed to write register 0x%02x with value 0x%02x.\n",
reg, val);
return rc;
}
/*
* Dump a complete mouse movement packet to the syslog
*/
static void elantech_packet_dump(unsigned char *packet, int size)
{
int i;
printk(KERN_DEBUG "elantech.c: PS/2 packet [");
for (i = 0; i < size; i++)
printk("%s0x%02x ", (i) ? ", " : " ", packet[i]);
printk("]\n");
}
/*
* Interpret complete data packets and report absolute mode input events for
* hardware version 1. (4 byte packets)
*/
static void elantech_report_absolute_v1(struct psmouse *psmouse)
{
struct input_dev *dev = psmouse->dev;
struct elantech_data *etd = psmouse->private;
unsigned char *packet = psmouse->packet;
int fingers;
static int old_fingers;
if (etd->fw_version_maj == 0x01) {
/* byte 0: D U p1 p2 1 p3 R L
byte 1: f 0 th tw x9 x8 y9 y8 */
fingers = ((packet[1] & 0x80) >> 7) +
((packet[1] & 0x30) >> 4);
} else {
/* byte 0: n1 n0 p2 p1 1 p3 R L
byte 1: 0 0 0 0 x9 x8 y9 y8 */
fingers = (packet[0] & 0xc0) >> 6;
}
if (etd->jumpy_cursor) {
/* Discard packets that are likely to have bogus coordinates */
if (fingers > old_fingers) {
elantech_debug("elantech.c: discarding packet\n");
goto discard_packet_v1;
}
}
input_report_key(dev, BTN_TOUCH, fingers != 0);
/* byte 2: x7 x6 x5 x4 x3 x2 x1 x0
byte 3: y7 y6 y5 y4 y3 y2 y1 y0 */
if (fingers) {
input_report_abs(dev, ABS_X,
((packet[1] & 0x0c) << 6) | packet[2]);
input_report_abs(dev, ABS_Y, ETP_YMAX_V1 -
(((packet[1] & 0x03) << 8) | packet[3]));
}
input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
if ((etd->fw_version_maj == 0x01) &&
(etd->capabilities & ETP_CAP_HAS_ROCKER)) {
/* rocker up */
input_report_key(dev, BTN_FORWARD, packet[0] & 0x40);
/* rocker down */
input_report_key(dev, BTN_BACK, packet[0] & 0x80);
}
input_sync(dev);
discard_packet_v1:
old_fingers = fingers;
}
/*
* Interpret complete data packets and report absolute mode input events for
* hardware version 2. (6 byte packets)
*/
static void elantech_report_absolute_v2(struct psmouse *psmouse)
{
struct input_dev *dev = psmouse->dev;
unsigned char *packet = psmouse->packet;
int fingers, x1, y1, x2, y2;
/* byte 0: n1 n0 . . . . R L */
fingers = (packet[0] & 0xc0) >> 6;
input_report_key(dev, BTN_TOUCH, fingers != 0);
switch (fingers) {
case 1:
/* byte 1: x15 x14 x13 x12 x11 x10 x9 x8
byte 2: x7 x6 x5 x4 x4 x2 x1 x0 */
input_report_abs(dev, ABS_X, (packet[1] << 8) | packet[2]);
/* byte 4: y15 y14 y13 y12 y11 y10 y8 y8
byte 5: y7 y6 y5 y4 y3 y2 y1 y0 */
input_report_abs(dev, ABS_Y, ETP_YMAX_V2 -
((packet[4] << 8) | packet[5]));
break;
case 2:
/* The coordinate of each finger is reported separately with
a lower resolution for two finger touches */
/* byte 0: . . ay8 ax8 . . . .
byte 1: ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0 */
x1 = ((packet[0] & 0x10) << 4) | packet[1];
/* byte 2: ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0 */
y1 = ETP_2FT_YMAX - (((packet[0] & 0x20) << 3) | packet[2]);
/* byte 3: . . by8 bx8 . . . .
byte 4: bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0 */
x2 = ((packet[3] & 0x10) << 4) | packet[4];
/* byte 5: by7 by8 by5 by4 by3 by2 by1 by0 */
y2 = ETP_2FT_YMAX - (((packet[3] & 0x20) << 3) | packet[5]);
/* For compatibility with the X Synaptics driver scale up one
coordinate and report as ordinary mouse movent */
input_report_abs(dev, ABS_X, x1 << 2);
input_report_abs(dev, ABS_Y, y1 << 2);
/* For compatibility with the proprietary X Elantech driver
report both coordinates as hat coordinates */
input_report_abs(dev, ABS_HAT0X, x1);
input_report_abs(dev, ABS_HAT0Y, y1);
input_report_abs(dev, ABS_HAT1X, x2);
input_report_abs(dev, ABS_HAT1Y, y2);
break;
}
input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
input_report_key(dev, BTN_LEFT, packet[0] & 0x01);
input_report_key(dev, BTN_RIGHT, packet[0] & 0x02);
input_sync(dev);
}
static int elantech_check_parity_v1(struct psmouse *psmouse)
{
struct elantech_data *etd = psmouse->private;
unsigned char *packet = psmouse->packet;
unsigned char p1, p2, p3;
/* Parity bits are placed differently */
if (etd->fw_version_maj == 0x01) {
/* byte 0: D U p1 p2 1 p3 R L */
p1 = (packet[0] & 0x20) >> 5;
p2 = (packet[0] & 0x10) >> 4;
} else {
/* byte 0: n1 n0 p2 p1 1 p3 R L */
p1 = (packet[0] & 0x10) >> 4;
p2 = (packet[0] & 0x20) >> 5;
}
p3 = (packet[0] & 0x04) >> 2;
return etd->parity[packet[1]] == p1 &&
etd->parity[packet[2]] == p2 &&
etd->parity[packet[3]] == p3;
}
/*
* Process byte stream from mouse and handle complete packets
*/
static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
{
struct elantech_data *etd = psmouse->private;
if (psmouse->pktcnt < psmouse->pktsize)
return PSMOUSE_GOOD_DATA;
if (etd->debug > 1)
elantech_packet_dump(psmouse->packet, psmouse->pktsize);
switch (etd->hw_version) {
case 1:
if (etd->paritycheck && !elantech_check_parity_v1(psmouse))
return PSMOUSE_BAD_DATA;
elantech_report_absolute_v1(psmouse);
break;
case 2:
/* We don't know how to check parity in protocol v2 */
elantech_report_absolute_v2(psmouse);
break;
}
return PSMOUSE_FULL_PACKET;
}
/*
* Put the touchpad into absolute mode
*/
static int elantech_set_absolute_mode(struct psmouse *psmouse)
{
struct elantech_data *etd = psmouse->private;
unsigned char val;
int tries = ETP_READ_BACK_TRIES;
int rc = 0;
switch (etd->hw_version) {
case 1:
etd->reg_10 = 0x16;
etd->reg_11 = 0x8f;
if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
elantech_write_reg(psmouse, 0x11, etd->reg_11)) {
rc = -1;
}
break;
case 2:
/* Windows driver values */
etd->reg_10 = 0x54;
etd->reg_11 = 0x88; /* 0x8a */
etd->reg_21 = 0x60; /* 0x00 */
if (elantech_write_reg(psmouse, 0x10, etd->reg_10) ||
elantech_write_reg(psmouse, 0x11, etd->reg_11) ||
elantech_write_reg(psmouse, 0x21, etd->reg_21)) {
rc = -1;
break;
}
}
if (rc == 0) {
/*
* Read back reg 0x10. For hardware version 1 we must make
* sure the absolute mode bit is set. For hardware version 2
* the touchpad is probably initalising and not ready until
* we read back the value we just wrote.
*/
do {
rc = elantech_read_reg(psmouse, 0x10, &val);
if (rc == 0)
break;
tries--;
elantech_debug("elantech.c: retrying read (%d).\n",
tries);
msleep(ETP_READ_BACK_DELAY);
} while (tries > 0);
if (rc) {
pr_err("elantech.c: failed to read back register 0x10.\n");
} else if (etd->hw_version == 1 &&
!(val & ETP_R10_ABSOLUTE_MODE)) {
pr_err("elantech.c: touchpad refuses "
"to switch to absolute mode.\n");
rc = -1;
}
}
if (rc)
pr_err("elantech.c: failed to initialise registers.\n");
return rc;
}
/*
* Set the appropriate event bits for the input subsystem
*/
static void elantech_set_input_params(struct psmouse *psmouse)
{
struct input_dev *dev = psmouse->dev;
struct elantech_data *etd = psmouse->private;
__set_bit(EV_KEY, dev->evbit);
__set_bit(EV_ABS, dev->evbit);
__clear_bit(EV_REL, dev->evbit);
__set_bit(BTN_LEFT, dev->keybit);
__set_bit(BTN_RIGHT, dev->keybit);
__set_bit(BTN_TOUCH, dev->keybit);
__set_bit(BTN_TOOL_FINGER, dev->keybit);
__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
switch (etd->hw_version) {
case 1:
/* Rocker button */
if ((etd->fw_version_maj == 0x01) &&
(etd->capabilities & ETP_CAP_HAS_ROCKER)) {
__set_bit(BTN_FORWARD, dev->keybit);
__set_bit(BTN_BACK, dev->keybit);
}
input_set_abs_params(dev, ABS_X, ETP_XMIN_V1, ETP_XMAX_V1, 0, 0);
input_set_abs_params(dev, ABS_Y, ETP_YMIN_V1, ETP_YMAX_V1, 0, 0);
break;
case 2:
input_set_abs_params(dev, ABS_X, ETP_XMIN_V2, ETP_XMAX_V2, 0, 0);
input_set_abs_params(dev, ABS_Y, ETP_YMIN_V2, ETP_YMAX_V2, 0, 0);
input_set_abs_params(dev, ABS_HAT0X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
input_set_abs_params(dev, ABS_HAT0Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
input_set_abs_params(dev, ABS_HAT1X, ETP_2FT_XMIN, ETP_2FT_XMAX, 0, 0);
input_set_abs_params(dev, ABS_HAT1Y, ETP_2FT_YMIN, ETP_2FT_YMAX, 0, 0);
break;
}
}
struct elantech_attr_data {
size_t field_offset;
unsigned char reg;
};
/*
* Display a register value by reading a sysfs entry
*/
static ssize_t elantech_show_int_attr(struct psmouse *psmouse, void *data,
char *buf)
{
struct elantech_data *etd = psmouse->private;
struct elantech_attr_data *attr = data;
unsigned char *reg = (unsigned char *) etd + attr->field_offset;
int rc = 0;
if (attr->reg)
rc = elantech_read_reg(psmouse, attr->reg, reg);
return sprintf(buf, "0x%02x\n", (attr->reg && rc) ? -1 : *reg);
}
/*
* Write a register value by writing a sysfs entry
*/
static ssize_t elantech_set_int_attr(struct psmouse *psmouse,
void *data, const char *buf, size_t count)
{
struct elantech_data *etd = psmouse->private;
struct elantech_attr_data *attr = data;
unsigned char *reg = (unsigned char *) etd + attr->field_offset;
unsigned long value;
int err;
err = strict_strtoul(buf, 16, &value);
if (err)
return err;
if (value > 0xff)
return -EINVAL;
/* Do we need to preserve some bits for version 2 hardware too? */
if (etd->hw_version == 1) {
if (attr->reg == 0x10)
/* Force absolute mode always on */
value |= ETP_R10_ABSOLUTE_MODE;
else if (attr->reg == 0x11)
/* Force 4 byte mode always on */
value |= ETP_R11_4_BYTE_MODE;
}
if (!attr->reg || elantech_write_reg(psmouse, attr->reg, value) == 0)
*reg = value;
return count;
}
#define ELANTECH_INT_ATTR(_name, _register) \
static struct elantech_attr_data elantech_attr_##_name = { \
.field_offset = offsetof(struct elantech_data, _name), \
.reg = _register, \
}; \
PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO, \
&elantech_attr_##_name, \
elantech_show_int_attr, \
elantech_set_int_attr)
ELANTECH_INT_ATTR(reg_10, 0x10);
ELANTECH_INT_ATTR(reg_11, 0x11);
ELANTECH_INT_ATTR(reg_20, 0x20);
ELANTECH_INT_ATTR(reg_21, 0x21);
ELANTECH_INT_ATTR(reg_22, 0x22);
ELANTECH_INT_ATTR(reg_23, 0x23);
ELANTECH_INT_ATTR(reg_24, 0x24);
ELANTECH_INT_ATTR(reg_25, 0x25);
ELANTECH_INT_ATTR(reg_26, 0x26);
ELANTECH_INT_ATTR(debug, 0);
ELANTECH_INT_ATTR(paritycheck, 0);
static struct attribute *elantech_attrs[] = {
&psmouse_attr_reg_10.dattr.attr,
&psmouse_attr_reg_11.dattr.attr,
&psmouse_attr_reg_20.dattr.attr,
&psmouse_attr_reg_21.dattr.attr,
&psmouse_attr_reg_22.dattr.attr,
&psmouse_attr_reg_23.dattr.attr,
&psmouse_attr_reg_24.dattr.attr,
&psmouse_attr_reg_25.dattr.attr,
&psmouse_attr_reg_26.dattr.attr,
&psmouse_attr_debug.dattr.attr,
&psmouse_attr_paritycheck.dattr.attr,
NULL
};
static struct attribute_group elantech_attr_group = {
.attrs = elantech_attrs,
};
/*
* Use magic knock to detect Elantech touchpad
*/
int elantech_detect(struct psmouse *psmouse, bool set_properties)
{
struct ps2dev *ps2dev = &psmouse->ps2dev;
unsigned char param[3];
ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
if (ps2_command(ps2dev, NULL, PSMOUSE_CMD_DISABLE) ||
ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) ||
ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) ||
ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11) ||
ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
pr_debug("elantech.c: sending Elantech magic knock failed.\n");
return -1;
}
/*
* Report this in case there are Elantech models that use a different
* set of magic numbers
*/
if (param[0] != 0x3c || param[1] != 0x03 || param[2] != 0xc8) {
pr_debug("elantech.c: "
"unexpected magic knock result 0x%02x, 0x%02x, 0x%02x.\n",
param[0], param[1], param[2]);
return -1;
}
/*
* Query touchpad's firmware version and see if it reports known
* value to avoid mis-detection. Logitech mice are known to respond
* to Elantech magic knock and there might be more.
*/
if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
pr_debug("elantech.c: failed to query firmware version.\n");
return -1;
}
pr_debug("elantech.c: Elantech version query result 0x%02x, 0x%02x, 0x%02x.\n",
param[0], param[1], param[2]);
if (param[0] == 0 || param[1] != 0) {
pr_debug("elantech.c: Probably not a real Elantech touchpad. Aborting.\n");
return -1;
}
if (set_properties) {
psmouse->vendor = "Elantech";
psmouse->name = "Touchpad";
}
return 0;
}
/*
* Clean up sysfs entries when disconnecting
*/
static void elantech_disconnect(struct psmouse *psmouse)
{
sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj,
&elantech_attr_group);
kfree(psmouse->private);
psmouse->private = NULL;
}
/*
* Put the touchpad back into absolute mode when reconnecting
*/
static int elantech_reconnect(struct psmouse *psmouse)
{
if (elantech_detect(psmouse, 0))
return -1;
if (elantech_set_absolute_mode(psmouse)) {
pr_err("elantech.c: failed to put touchpad back into absolute mode.\n");
return -1;
}
return 0;
}
/*
* Initialize the touchpad and create sysfs entries
*/
int elantech_init(struct psmouse *psmouse)
{
struct elantech_data *etd;
int i, error;
unsigned char param[3];
psmouse->private = etd = kzalloc(sizeof(struct elantech_data), GFP_KERNEL);
if (!etd)
return -1;
etd->parity[0] = 1;
for (i = 1; i < 256; i++)
etd->parity[i] = etd->parity[i & (i - 1)] ^ 1;
/*
* Do the version query again so we can store the result
*/
if (synaptics_send_cmd(psmouse, ETP_FW_VERSION_QUERY, param)) {
pr_err("elantech.c: failed to query firmware version.\n");
goto init_fail;
}
etd->fw_version_maj = param[0];
etd->fw_version_min = param[2];
/*
* Assume every version greater than this is new EeePC style
* hardware with 6 byte packets
*/
if (etd->fw_version_maj >= 0x02 && etd->fw_version_min >= 0x30) {
etd->hw_version = 2;
/* For now show extra debug information */
etd->debug = 1;
/* Don't know how to do parity checking for version 2 */
etd->paritycheck = 0;
} else {
etd->hw_version = 1;
etd->paritycheck = 1;
}
pr_info("elantech.c: assuming hardware version %d, firmware version %d.%d\n",
etd->hw_version, etd->fw_version_maj, etd->fw_version_min);
if (synaptics_send_cmd(psmouse, ETP_CAPABILITIES_QUERY, param)) {
pr_err("elantech.c: failed to query capabilities.\n");
goto init_fail;
}
pr_info("elantech.c: Synaptics capabilities query result 0x%02x, 0x%02x, 0x%02x.\n",
param[0], param[1], param[2]);
etd->capabilities = param[0];
/*
* This firmware seems to suffer from misreporting coordinates when
* a touch action starts causing the mouse cursor or scrolled page
* to jump. Enable a workaround.
*/
if (etd->fw_version_maj == 0x02 && etd->fw_version_min == 0x22) {
pr_info("elantech.c: firmware version 2.34 detected, "
"enabling jumpy cursor workaround\n");
etd->jumpy_cursor = 1;
}
if (elantech_set_absolute_mode(psmouse)) {
pr_err("elantech.c: failed to put touchpad into absolute mode.\n");
goto init_fail;
}
elantech_set_input_params(psmouse);
error = sysfs_create_group(&psmouse->ps2dev.serio->dev.kobj,
&elantech_attr_group);
if (error) {
pr_err("elantech.c: failed to create sysfs attributes, error: %d.\n",
error);
goto init_fail;
}
psmouse->protocol_handler = elantech_process_byte;
psmouse->disconnect = elantech_disconnect;
psmouse->reconnect = elantech_reconnect;
psmouse->pktsize = etd->hw_version == 2 ? 6 : 4;
return 0;
init_fail:
kfree(etd);
return -1;
}