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linux/usb/serial.h>
#include"
pl2303.h"
*VersionInformation
#defineDRIVER_AUTHOR"
GregKroah-Hartman,greg@,
#defineDRIVER_DESC"
USBSerialDrivercore"
staticvoidport_free（structusb_serial_port*port）;
/*DriverstructureweregisterwiththeUSBcore*/
staticstructusb_driverusb_serial_driver={
.name="
usbserial"
.probe=usb_serial_probe,
.disconnect=usb_serial_disconnect,
.suspend=usb_serial_suspend,
.resume=usb_serial_resume,
.no_dynamic_id=1,
};
/*ThereisnoMODULE_DEVICE_TABLEforusbserial.c.Instead
theMODULE_DEVICE_TABLEdeclarationsineachserialdriver
causethe"
hotplug"
programtopullinwhatevermoduleisnecessary
viamodprobe,andmodprobewillloadusbserialbecausetheserial
driversdependonit.
*/
staticintdebug;
/*initiallyallNULL*/
staticstructusb_serial*serial_table[SERIAL_TTY_MINORS];
staticDEFINE_MUTEX（table_lock）;
staticLIST_HEAD（usb_serial_driver_list）;
structusb_serial*usb_serial_get_by_index（unsignedindex）
{
structusb_serial*serial;
mutex_lock（&
table_lock）;
serial=serial_table[index];
if（serial）
kref_get（&
serial->
kref）;
mutex_unlock（&
returnserial;
}
staticstructusb_serial*get_free_serial（structusb_serial*serial,
intnum_ports,unsignedint*minor）
unsignedinti,j;
intgood_spot;
dbg（"
%s%d"
__func__,num_ports）;
*minor=0;
for（i=0;
i<
SERIAL_TTY_MINORS;
++i）{
if（serial_table[i]）
continue;
good_spot=1;
for（j=1;
j<
=num_ports-1;
++j）
if（（i+j>
=SERIAL_TTY_MINORS）||（serial_table[i+j]））{
good_spot=0;
i+=j;
break;
}
if（good_spot==0）
*minor=i;
j=0;
dbg（"
%s-minorbase=%d"
__func__,*minor）;
for（i=*minor;
（i<
（*minor+num_ports））&
&
SERIAL_TTY_MINORS）;
serial_table[i]=serial;
serial->
port[j++]->
number=i;
}
mutex_unlock（&
returnserial;
}
returnNULL;
staticvoidreturn_serial（structusb_serial*serial）
inti;
%s"
__func__）;
serial->
num_ports;
++i）
serial_table[serial->
minor+i]=NULL;
staticvoiddestroy_serial（structkref*kref）
structusb_serial_port*port;
serial=to_usb_serial（kref）;
%s-%s"
__func__,serial->
type->
description）;
/*returntheminorrangethatthisdevicehad*/
if（serial->
minor!
=SERIAL_TTY_NO_MINOR）
return_serial（serial）;
release（serial）;
port=serial->
port[i];
if（port）
put_device（&
port->
dev）;
/*Ifthisisa"
fake"
port,wehavetocleanituphere,asitwill
*notgetcleanedupinport_release（）asitwasneverregisteredwith
*thedrivercore*/
num_ports<
num_port_pointers）{
for（i=serial->
i<
num_port_pointers;
port=serial->
if（port）
port_free（port）;
usb_put_dev（serial->
/*freeupanymemorythatweallocated*/
kfree（serial）;
voidusb_serial_put（structusb_serial*serial）
kref_put（&
kref,destroy_serial）;
/*****************************************************************************
*Driverttyinterfacefunctions
*****************************************************************************/
staticintserial_open（structtty_struct*tty,structfile*filp）
unsignedintportNumber;
intretval=0;
/*gettheserialobjectassociatedwiththisttypointer*/
serial=usb_serial_get_by_index（tty->
index）;
if（!
serial）{
tty->
driver_data=NULL;
return-ENODEV;
disc_mutex）;
portNumber=tty->
index-serial->
minor;
port=serial->
port[portNumber];
port||serial->
disconnected）
retval=-ENODEV;
else
get_device（&
/*
*Note:
Ourlockingorderrequirementdoesnotallowport->
mutex
*tobeacquiredwhileserial->
disc_mutexisheld.
if（retval）
gotobailout_serial_put;
if（mutex_lock_interruptible（&
mutex））{
retval=-ERESTARTSYS;
gotobailout_port_put;
++port->
port.count;
/*setupourportstructuremakingthettydriver
*rememberourportobject,andusit*/
tty->
driver_data=port;
tty_port_tty_set（&
port,tty）;
if（port->
port.count==1）{
/*lockthismodulebeforewecallit
*thismayfail,whichmeanswemustbailout,
*safebecausewearecalledwithBKLheld*/
if（!
try_module_get（serial->
driver.owner））{
retval=-ENODEV;
gotobailout_mutex_unlock;
mutex_lock（&
if（serial->
else
retval=usb_autopm_get_interface（serial->
interface）;
if（retval）
gotobailout_module_put;
/*onlycallthedevicespecificopenifthis
*isthefirsttimetheportisopened*/
retval=serial->
open（tty,port,filp）;
gotobailout_interface_put;
mutex）;
return0;
bailout_interface_put:
usb_autopm_put_interface（serial->
bailout_module_put:
module_put（serial->
driver.owner）;
bailout_mutex_unlock:
port->
port.count=0;
port,NULL）;
bailout_port_put:
put_device（&
bailout_serial_put:
usb_serial_put（serial）;
returnretval;
staticvoidserial_close（structtty_struct*tty,structfile*filp）
structusb_serial_port*port=tty->
driver_data;
structmodule*owner;
intcount;
port）
return;
%s-port%d"
__func__,port->
number）;
serial=port->
serial;
owner=serial->
driver.owner;
port.count==0）{
port.count==1）
/*onlycallthedevicespecificcloseifthis
*portisbeingclosedbythelastowner.Ensurewedo
*thisbeforewedroptheportcount.Thecallisprotected
*bytheportmutex
*/
serial->
close（tty,port,filp）;
port.count==（port->
console?
2:
1））{
structtty_struct*tty=tty_port_tty_get（&
port）;
if（tty）{
/*Wemustdothisbeforewedroptheportcountto
zero.*/
if（tty->
driver_data）
tty->
tty_port_tty_set（&
tty_kref_put（tty）;
--port->
count=port->
/*Mustn'
tdereferenceportanymore*/
if（count==0）{
usb_autopm_put_interface（serial->
tdereferenceserialanymore*/
if（count==0）
module_put（owner）;
staticintserial_write（structtty_struct*tty,constunsignedchar*buf,
intcount）
intretval=-ENODEV;
dev->
state==USB_STATE_NOTATTACHED）
gotoexit;
%s-port%d,%dbyte（s）"
number,count）;
/*countismanagedunderthemutexlockforthettysocannot
droptozerountilafterthelastclosecompletes*/
WARN_ON（!
port.count）;
/*passontothedriverspecificversionofthisfunction*/
retval=port->
write（tty,port,buf,count）;
exit:
staticintserial_write_room（structtty_struct*tty）
returnport->
write_room（tty）;
staticintserial_chars_in_buffer（structtty_struct*tty）
%s=port%d"
/*ifthedevicewasunpluggedthenanyremainingcharacters
felloutoftheconnector;
）*/
return0;
chars_in_buffer（tty）;
staticvoidserial_throttle（structtty_struct*tty）
th
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