OpenCloudOS-Kernel/drivers/hid/hid-lg4ff.c

759 lines
20 KiB
C

/*
* Force feedback support for Logitech Gaming Wheels
*
* Including G27, G25, DFP, DFGT, FFEX, Momo, Momo2 &
* Speed Force Wireless (WiiWheel)
*
* Copyright (c) 2010 Simon Wood <simon@mungewell.org>
*/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/input.h>
#include <linux/usb.h>
#include <linux/hid.h>
#include "usbhid/usbhid.h"
#include "hid-lg.h"
#include "hid-ids.h"
#define DFGT_REV_MAJ 0x13
#define DFGT_REV_MIN 0x22
#define DFGT2_REV_MIN 0x26
#define DFP_REV_MAJ 0x11
#define DFP_REV_MIN 0x06
#define FFEX_REV_MAJ 0x21
#define FFEX_REV_MIN 0x00
#define G25_REV_MAJ 0x12
#define G25_REV_MIN 0x22
#define G27_REV_MAJ 0x12
#define G27_REV_MIN 0x38
#define G27_2_REV_MIN 0x39
#define to_hid_device(pdev) container_of(pdev, struct hid_device, dev)
static void hid_lg4ff_set_range_dfp(struct hid_device *hid, u16 range);
static void hid_lg4ff_set_range_g25(struct hid_device *hid, u16 range);
static ssize_t lg4ff_range_show(struct device *dev, struct device_attribute *attr, char *buf);
static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count);
static DEVICE_ATTR(range, S_IRWXU | S_IRWXG | S_IROTH, lg4ff_range_show, lg4ff_range_store);
struct lg4ff_device_entry {
__u32 product_id;
__u16 range;
__u16 min_range;
__u16 max_range;
#ifdef CONFIG_LEDS_CLASS
__u8 led_state;
struct led_classdev *led[5];
#endif
struct list_head list;
void (*set_range)(struct hid_device *hid, u16 range);
};
static const signed short lg4ff_wheel_effects[] = {
FF_CONSTANT,
FF_AUTOCENTER,
-1
};
struct lg4ff_wheel {
const __u32 product_id;
const signed short *ff_effects;
const __u16 min_range;
const __u16 max_range;
void (*set_range)(struct hid_device *hid, u16 range);
};
static const struct lg4ff_wheel lg4ff_devices[] = {
{USB_DEVICE_ID_LOGITECH_WHEEL, lg4ff_wheel_effects, 40, 270, NULL},
{USB_DEVICE_ID_LOGITECH_MOMO_WHEEL, lg4ff_wheel_effects, 40, 270, NULL},
{USB_DEVICE_ID_LOGITECH_DFP_WHEEL, lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_dfp},
{USB_DEVICE_ID_LOGITECH_G25_WHEEL, lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_g25},
{USB_DEVICE_ID_LOGITECH_DFGT_WHEEL, lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_g25},
{USB_DEVICE_ID_LOGITECH_G27_WHEEL, lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_g25},
{USB_DEVICE_ID_LOGITECH_MOMO_WHEEL2, lg4ff_wheel_effects, 40, 270, NULL},
{USB_DEVICE_ID_LOGITECH_WII_WHEEL, lg4ff_wheel_effects, 40, 270, NULL}
};
struct lg4ff_native_cmd {
const __u8 cmd_num; /* Number of commands to send */
const __u8 cmd[];
};
struct lg4ff_usb_revision {
const __u16 rev_maj;
const __u16 rev_min;
const struct lg4ff_native_cmd *command;
};
static const struct lg4ff_native_cmd native_dfp = {
1,
{0xf8, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00}
};
static const struct lg4ff_native_cmd native_dfgt = {
2,
{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, /* 1st command */
0xf8, 0x09, 0x03, 0x01, 0x00, 0x00, 0x00} /* 2nd command */
};
static const struct lg4ff_native_cmd native_g25 = {
1,
{0xf8, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00}
};
static const struct lg4ff_native_cmd native_g27 = {
2,
{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, /* 1st command */
0xf8, 0x09, 0x04, 0x01, 0x00, 0x00, 0x00} /* 2nd command */
};
static const struct lg4ff_usb_revision lg4ff_revs[] = {
{DFGT_REV_MAJ, DFGT_REV_MIN, &native_dfgt}, /* Driving Force GT */
{DFGT_REV_MAJ, DFGT2_REV_MIN, &native_dfgt}, /* Driving Force GT v2 */
{DFP_REV_MAJ, DFP_REV_MIN, &native_dfp}, /* Driving Force Pro */
{G25_REV_MAJ, G25_REV_MIN, &native_g25}, /* G25 */
{G27_REV_MAJ, G27_REV_MIN, &native_g27}, /* G27 */
{G27_REV_MAJ, G27_2_REV_MIN, &native_g27}, /* G27 v2 */
};
/* Recalculates X axis value accordingly to currently selected range */
static __s32 lg4ff_adjust_dfp_x_axis(__s32 value, __u16 range)
{
__u16 max_range;
__s32 new_value;
if (range == 900)
return value;
else if (range == 200)
return value;
else if (range < 200)
max_range = 200;
else
max_range = 900;
new_value = 8192 + mult_frac(value - 8192, max_range, range);
if (new_value < 0)
return 0;
else if (new_value > 16383)
return 16383;
else
return new_value;
}
int lg4ff_adjust_input_event(struct hid_device *hid, struct hid_field *field,
struct hid_usage *usage, __s32 value, struct lg_drv_data *drv_data)
{
struct lg4ff_device_entry *entry = drv_data->device_props;
__s32 new_value = 0;
if (!entry) {
hid_err(hid, "Device properties not found");
return 0;
}
switch (entry->product_id) {
case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
switch (usage->code) {
case ABS_X:
new_value = lg4ff_adjust_dfp_x_axis(value, entry->range);
input_event(field->hidinput->input, usage->type, usage->code, new_value);
return 1;
default:
return 0;
}
default:
return 0;
}
}
static int hid_lg4ff_play(struct input_dev *dev, void *data, struct ff_effect *effect)
{
struct hid_device *hid = input_get_drvdata(dev);
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
__s32 *value = report->field[0]->value;
int x;
#define CLAMP(x) do { if (x < 0) x = 0; else if (x > 0xff) x = 0xff; } while (0)
switch (effect->type) {
case FF_CONSTANT:
x = effect->u.ramp.start_level + 0x80; /* 0x80 is no force */
CLAMP(x);
if (x == 0x80) {
/* De-activate force in slot-1*/
value[0] = 0x13;
value[1] = 0x00;
value[2] = 0x00;
value[3] = 0x00;
value[4] = 0x00;
value[5] = 0x00;
value[6] = 0x00;
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
return 0;
}
value[0] = 0x11; /* Slot 1 */
value[1] = 0x08;
value[2] = x;
value[3] = 0x80;
value[4] = 0x00;
value[5] = 0x00;
value[6] = 0x00;
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
break;
}
return 0;
}
/* Sends default autocentering command compatible with
* all wheels except Formula Force EX */
static void hid_lg4ff_set_autocenter_default(struct input_dev *dev, u16 magnitude)
{
struct hid_device *hid = input_get_drvdata(dev);
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
__s32 *value = report->field[0]->value;
__u32 expand_a, expand_b;
struct lg4ff_device_entry *entry;
struct lg_drv_data *drv_data;
drv_data = hid_get_drvdata(hid);
if (!drv_data) {
hid_err(hid, "Private driver data not found!\n");
return;
}
entry = drv_data->device_props;
if (!entry) {
hid_err(hid, "Device properties not found!\n");
return;
}
/* De-activate Auto-Center */
if (magnitude == 0) {
value[0] = 0xf5;
value[1] = 0x00;
value[2] = 0x00;
value[3] = 0x00;
value[4] = 0x00;
value[5] = 0x00;
value[6] = 0x00;
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
return;
}
if (magnitude <= 0xaaaa) {
expand_a = 0x0c * magnitude;
expand_b = 0x80 * magnitude;
} else {
expand_a = (0x0c * 0xaaaa) + 0x06 * (magnitude - 0xaaaa);
expand_b = (0x80 * 0xaaaa) + 0xff * (magnitude - 0xaaaa);
}
/* Adjust for non-MOMO wheels */
switch (entry->product_id) {
case USB_DEVICE_ID_LOGITECH_MOMO_WHEEL:
case USB_DEVICE_ID_LOGITECH_MOMO_WHEEL2:
break;
default:
expand_a = expand_a >> 1;
break;
}
value[0] = 0xfe;
value[1] = 0x0d;
value[2] = expand_a / 0xaaaa;
value[3] = expand_a / 0xaaaa;
value[4] = expand_b / 0xaaaa;
value[5] = 0x00;
value[6] = 0x00;
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
/* Activate Auto-Center */
value[0] = 0x14;
value[1] = 0x00;
value[2] = 0x00;
value[3] = 0x00;
value[4] = 0x00;
value[5] = 0x00;
value[6] = 0x00;
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
}
/* Sends autocentering command compatible with Formula Force EX */
static void hid_lg4ff_set_autocenter_ffex(struct input_dev *dev, u16 magnitude)
{
struct hid_device *hid = input_get_drvdata(dev);
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
__s32 *value = report->field[0]->value;
magnitude = magnitude * 90 / 65535;
value[0] = 0xfe;
value[1] = 0x03;
value[2] = magnitude >> 14;
value[3] = magnitude >> 14;
value[4] = magnitude;
value[5] = 0x00;
value[6] = 0x00;
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
}
/* Sends command to set range compatible with G25/G27/Driving Force GT */
static void hid_lg4ff_set_range_g25(struct hid_device *hid, u16 range)
{
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
__s32 *value = report->field[0]->value;
dbg_hid("G25/G27/DFGT: setting range to %u\n", range);
value[0] = 0xf8;
value[1] = 0x81;
value[2] = range & 0x00ff;
value[3] = (range & 0xff00) >> 8;
value[4] = 0x00;
value[5] = 0x00;
value[6] = 0x00;
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
}
/* Sends commands to set range compatible with Driving Force Pro wheel */
static void hid_lg4ff_set_range_dfp(struct hid_device *hid, __u16 range)
{
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
int start_left, start_right, full_range;
__s32 *value = report->field[0]->value;
dbg_hid("Driving Force Pro: setting range to %u\n", range);
/* Prepare "coarse" limit command */
value[0] = 0xf8;
value[1] = 0x00; /* Set later */
value[2] = 0x00;
value[3] = 0x00;
value[4] = 0x00;
value[5] = 0x00;
value[6] = 0x00;
if (range > 200) {
report->field[0]->value[1] = 0x03;
full_range = 900;
} else {
report->field[0]->value[1] = 0x02;
full_range = 200;
}
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
/* Prepare "fine" limit command */
value[0] = 0x81;
value[1] = 0x0b;
value[2] = 0x00;
value[3] = 0x00;
value[4] = 0x00;
value[5] = 0x00;
value[6] = 0x00;
if (range == 200 || range == 900) { /* Do not apply any fine limit */
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
return;
}
/* Construct fine limit command */
start_left = (((full_range - range + 1) * 2047) / full_range);
start_right = 0xfff - start_left;
value[2] = start_left >> 4;
value[3] = start_right >> 4;
value[4] = 0xff;
value[5] = (start_right & 0xe) << 4 | (start_left & 0xe);
value[6] = 0xff;
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
}
static void hid_lg4ff_switch_native(struct hid_device *hid, const struct lg4ff_native_cmd *cmd)
{
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
__u8 i, j;
j = 0;
while (j < 7*cmd->cmd_num) {
for (i = 0; i < 7; i++)
report->field[0]->value[i] = cmd->cmd[j++];
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
}
}
/* Read current range and display it in terminal */
static ssize_t lg4ff_range_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct hid_device *hid = to_hid_device(dev);
struct lg4ff_device_entry *entry;
struct lg_drv_data *drv_data;
size_t count;
drv_data = hid_get_drvdata(hid);
if (!drv_data) {
hid_err(hid, "Private driver data not found!\n");
return 0;
}
entry = drv_data->device_props;
if (!entry) {
hid_err(hid, "Device properties not found!\n");
return 0;
}
count = scnprintf(buf, PAGE_SIZE, "%u\n", entry->range);
return count;
}
/* Set range to user specified value, call appropriate function
* according to the type of the wheel */
static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
struct hid_device *hid = to_hid_device(dev);
struct lg4ff_device_entry *entry;
struct lg_drv_data *drv_data;
__u16 range = simple_strtoul(buf, NULL, 10);
drv_data = hid_get_drvdata(hid);
if (!drv_data) {
hid_err(hid, "Private driver data not found!\n");
return -EINVAL;
}
entry = drv_data->device_props;
if (!entry) {
hid_err(hid, "Device properties not found!\n");
return -EINVAL;
}
if (range == 0)
range = entry->max_range;
/* Check if the wheel supports range setting
* and that the range is within limits for the wheel */
if (entry->set_range != NULL && range >= entry->min_range && range <= entry->max_range) {
entry->set_range(hid, range);
entry->range = range;
}
return count;
}
#ifdef CONFIG_LEDS_CLASS
static void lg4ff_set_leds(struct hid_device *hid, __u8 leds)
{
struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
__s32 *value = report->field[0]->value;
value[0] = 0xf8;
value[1] = 0x12;
value[2] = leds;
value[3] = 0x00;
value[4] = 0x00;
value[5] = 0x00;
value[6] = 0x00;
hid_hw_request(hid, report, HID_REQ_SET_REPORT);
}
static void lg4ff_led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct device *dev = led_cdev->dev->parent;
struct hid_device *hid = container_of(dev, struct hid_device, dev);
struct lg_drv_data *drv_data = hid_get_drvdata(hid);
struct lg4ff_device_entry *entry;
int i, state = 0;
if (!drv_data) {
hid_err(hid, "Device data not found.");
return;
}
entry = (struct lg4ff_device_entry *)drv_data->device_props;
if (!entry) {
hid_err(hid, "Device properties not found.");
return;
}
for (i = 0; i < 5; i++) {
if (led_cdev != entry->led[i])
continue;
state = (entry->led_state >> i) & 1;
if (value == LED_OFF && state) {
entry->led_state &= ~(1 << i);
lg4ff_set_leds(hid, entry->led_state);
} else if (value != LED_OFF && !state) {
entry->led_state |= 1 << i;
lg4ff_set_leds(hid, entry->led_state);
}
break;
}
}
static enum led_brightness lg4ff_led_get_brightness(struct led_classdev *led_cdev)
{
struct device *dev = led_cdev->dev->parent;
struct hid_device *hid = container_of(dev, struct hid_device, dev);
struct lg_drv_data *drv_data = hid_get_drvdata(hid);
struct lg4ff_device_entry *entry;
int i, value = 0;
if (!drv_data) {
hid_err(hid, "Device data not found.");
return LED_OFF;
}
entry = (struct lg4ff_device_entry *)drv_data->device_props;
if (!entry) {
hid_err(hid, "Device properties not found.");
return LED_OFF;
}
for (i = 0; i < 5; i++)
if (led_cdev == entry->led[i]) {
value = (entry->led_state >> i) & 1;
break;
}
return value ? LED_FULL : LED_OFF;
}
#endif
int lg4ff_init(struct hid_device *hid)
{
struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
struct input_dev *dev = hidinput->input;
struct lg4ff_device_entry *entry;
struct lg_drv_data *drv_data;
struct usb_device_descriptor *udesc;
int error, i, j;
__u16 bcdDevice, rev_maj, rev_min;
/* Check that the report looks ok */
if (!hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 7))
return -1;
/* Check what wheel has been connected */
for (i = 0; i < ARRAY_SIZE(lg4ff_devices); i++) {
if (hid->product == lg4ff_devices[i].product_id) {
dbg_hid("Found compatible device, product ID %04X\n", lg4ff_devices[i].product_id);
break;
}
}
if (i == ARRAY_SIZE(lg4ff_devices)) {
hid_err(hid, "Device is not supported by lg4ff driver. If you think it should be, consider reporting a bug to"
"LKML, Simon Wood <simon@mungewell.org> or Michal Maly <madcatxster@gmail.com>\n");
return -1;
}
/* Attempt to switch wheel to native mode when applicable */
udesc = &(hid_to_usb_dev(hid)->descriptor);
if (!udesc) {
hid_err(hid, "NULL USB device descriptor\n");
return -1;
}
bcdDevice = le16_to_cpu(udesc->bcdDevice);
rev_maj = bcdDevice >> 8;
rev_min = bcdDevice & 0xff;
if (lg4ff_devices[i].product_id == USB_DEVICE_ID_LOGITECH_WHEEL) {
dbg_hid("Generic wheel detected, can it do native?\n");
dbg_hid("USB revision: %2x.%02x\n", rev_maj, rev_min);
for (j = 0; j < ARRAY_SIZE(lg4ff_revs); j++) {
if (lg4ff_revs[j].rev_maj == rev_maj && lg4ff_revs[j].rev_min == rev_min) {
hid_lg4ff_switch_native(hid, lg4ff_revs[j].command);
hid_info(hid, "Switched to native mode\n");
}
}
}
/* Set supported force feedback capabilities */
for (j = 0; lg4ff_devices[i].ff_effects[j] >= 0; j++)
set_bit(lg4ff_devices[i].ff_effects[j], dev->ffbit);
error = input_ff_create_memless(dev, NULL, hid_lg4ff_play);
if (error)
return error;
/* Get private driver data */
drv_data = hid_get_drvdata(hid);
if (!drv_data) {
hid_err(hid, "Cannot add device, private driver data not allocated\n");
return -1;
}
/* Initialize device properties */
entry = kzalloc(sizeof(struct lg4ff_device_entry), GFP_KERNEL);
if (!entry) {
hid_err(hid, "Cannot add device, insufficient memory to allocate device properties.\n");
return -ENOMEM;
}
drv_data->device_props = entry;
entry->product_id = lg4ff_devices[i].product_id;
entry->min_range = lg4ff_devices[i].min_range;
entry->max_range = lg4ff_devices[i].max_range;
entry->set_range = lg4ff_devices[i].set_range;
/* Check if autocentering is available and
* set the centering force to zero by default */
if (test_bit(FF_AUTOCENTER, dev->ffbit)) {
if (rev_maj == FFEX_REV_MAJ && rev_min == FFEX_REV_MIN) /* Formula Force EX expects different autocentering command */
dev->ff->set_autocenter = hid_lg4ff_set_autocenter_ffex;
else
dev->ff->set_autocenter = hid_lg4ff_set_autocenter_default;
dev->ff->set_autocenter(dev, 0);
}
/* Create sysfs interface */
error = device_create_file(&hid->dev, &dev_attr_range);
if (error)
return error;
dbg_hid("sysfs interface created\n");
/* Set the maximum range to start with */
entry->range = entry->max_range;
if (entry->set_range != NULL)
entry->set_range(hid, entry->range);
#ifdef CONFIG_LEDS_CLASS
/* register led subsystem - G27 only */
entry->led_state = 0;
for (j = 0; j < 5; j++)
entry->led[j] = NULL;
if (lg4ff_devices[i].product_id == USB_DEVICE_ID_LOGITECH_G27_WHEEL) {
struct led_classdev *led;
size_t name_sz;
char *name;
lg4ff_set_leds(hid, 0);
name_sz = strlen(dev_name(&hid->dev)) + 8;
for (j = 0; j < 5; j++) {
led = kzalloc(sizeof(struct led_classdev)+name_sz, GFP_KERNEL);
if (!led) {
hid_err(hid, "can't allocate memory for LED %d\n", j);
goto err;
}
name = (void *)(&led[1]);
snprintf(name, name_sz, "%s::RPM%d", dev_name(&hid->dev), j+1);
led->name = name;
led->brightness = 0;
led->max_brightness = 1;
led->brightness_get = lg4ff_led_get_brightness;
led->brightness_set = lg4ff_led_set_brightness;
entry->led[j] = led;
error = led_classdev_register(&hid->dev, led);
if (error) {
hid_err(hid, "failed to register LED %d. Aborting.\n", j);
err:
/* Deregister LEDs (if any) */
for (j = 0; j < 5; j++) {
led = entry->led[j];
entry->led[j] = NULL;
if (!led)
continue;
led_classdev_unregister(led);
kfree(led);
}
goto out; /* Let the driver continue without LEDs */
}
}
}
out:
#endif
hid_info(hid, "Force feedback support for Logitech Gaming Wheels\n");
return 0;
}
int lg4ff_deinit(struct hid_device *hid)
{
struct lg4ff_device_entry *entry;
struct lg_drv_data *drv_data;
device_remove_file(&hid->dev, &dev_attr_range);
drv_data = hid_get_drvdata(hid);
if (!drv_data) {
hid_err(hid, "Error while deinitializing device, no private driver data.\n");
return -1;
}
entry = drv_data->device_props;
if (!entry) {
hid_err(hid, "Error while deinitializing device, no device properties data.\n");
return -1;
}
#ifdef CONFIG_LEDS_CLASS
{
int j;
struct led_classdev *led;
/* Deregister LEDs (if any) */
for (j = 0; j < 5; j++) {
led = entry->led[j];
entry->led[j] = NULL;
if (!led)
continue;
led_classdev_unregister(led);
kfree(led);
}
}
#endif
/* Deallocate memory */
kfree(entry);
dbg_hid("Device successfully unregistered\n");
return 0;
}