mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 14:26:41 +07:00
73e487fdb7
Prevent sending further output to a USB-serial console after the dongle is disconnected, take care not to leak kref. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
299 lines
6.6 KiB
C
299 lines
6.6 KiB
C
/*
|
|
* USB Serial Console driver
|
|
*
|
|
* Copyright (C) 2001 - 2002 Greg Kroah-Hartman (greg@kroah.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.
|
|
*
|
|
* Thanks to Randy Dunlap for the original version of this code.
|
|
*
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/console.h>
|
|
#include <linux/usb.h>
|
|
|
|
static int debug;
|
|
|
|
#include "usb-serial.h"
|
|
|
|
struct usbcons_info {
|
|
int magic;
|
|
int break_flag;
|
|
struct usb_serial_port *port;
|
|
};
|
|
|
|
static struct usbcons_info usbcons_info;
|
|
static struct console usbcons;
|
|
|
|
/*
|
|
* ------------------------------------------------------------
|
|
* USB Serial console driver
|
|
*
|
|
* Much of the code here is copied from drivers/char/serial.c
|
|
* and implements a phony serial console in the same way that
|
|
* serial.c does so that in case some software queries it,
|
|
* it will get the same results.
|
|
*
|
|
* Things that are different from the way the serial port code
|
|
* does things, is that we call the lower level usb-serial
|
|
* driver code to initialize the device, and we set the initial
|
|
* console speeds based on the command line arguments.
|
|
* ------------------------------------------------------------
|
|
*/
|
|
|
|
|
|
/*
|
|
* The parsing of the command line works exactly like the
|
|
* serial.c code, except that the specifier is "ttyUSB" instead
|
|
* of "ttyS".
|
|
*/
|
|
static int usb_console_setup(struct console *co, char *options)
|
|
{
|
|
struct usbcons_info *info = &usbcons_info;
|
|
int baud = 9600;
|
|
int bits = 8;
|
|
int parity = 'n';
|
|
int doflow = 0;
|
|
int cflag = CREAD | HUPCL | CLOCAL;
|
|
char *s;
|
|
struct usb_serial *serial;
|
|
struct usb_serial_port *port;
|
|
int retval = 0;
|
|
struct tty_struct *tty;
|
|
struct termios *termios;
|
|
|
|
dbg ("%s", __FUNCTION__);
|
|
|
|
if (options) {
|
|
baud = simple_strtoul(options, NULL, 10);
|
|
s = options;
|
|
while (*s >= '0' && *s <= '9')
|
|
s++;
|
|
if (*s)
|
|
parity = *s++;
|
|
if (*s)
|
|
bits = *s++ - '0';
|
|
if (*s)
|
|
doflow = (*s++ == 'r');
|
|
}
|
|
|
|
/* build a cflag setting */
|
|
switch (baud) {
|
|
case 1200:
|
|
cflag |= B1200;
|
|
break;
|
|
case 2400:
|
|
cflag |= B2400;
|
|
break;
|
|
case 4800:
|
|
cflag |= B4800;
|
|
break;
|
|
case 19200:
|
|
cflag |= B19200;
|
|
break;
|
|
case 38400:
|
|
cflag |= B38400;
|
|
break;
|
|
case 57600:
|
|
cflag |= B57600;
|
|
break;
|
|
case 115200:
|
|
cflag |= B115200;
|
|
break;
|
|
case 9600:
|
|
default:
|
|
cflag |= B9600;
|
|
/*
|
|
* Set this to a sane value to prevent a divide error
|
|
*/
|
|
baud = 9600;
|
|
break;
|
|
}
|
|
switch (bits) {
|
|
case 7:
|
|
cflag |= CS7;
|
|
break;
|
|
default:
|
|
case 8:
|
|
cflag |= CS8;
|
|
break;
|
|
}
|
|
switch (parity) {
|
|
case 'o': case 'O':
|
|
cflag |= PARODD;
|
|
break;
|
|
case 'e': case 'E':
|
|
cflag |= PARENB;
|
|
break;
|
|
}
|
|
co->cflag = cflag;
|
|
|
|
/* grab the first serial port that happens to be connected */
|
|
serial = usb_serial_get_by_index(0);
|
|
if (serial == NULL) {
|
|
/* no device is connected yet, sorry :( */
|
|
err ("No USB device connected to ttyUSB0");
|
|
return -ENODEV;
|
|
}
|
|
|
|
port = serial->port[0];
|
|
port->tty = NULL;
|
|
|
|
info->port = port;
|
|
|
|
++port->open_count;
|
|
if (port->open_count == 1) {
|
|
/* only call the device specific open if this
|
|
* is the first time the port is opened */
|
|
if (serial->type->open)
|
|
retval = serial->type->open(port, NULL);
|
|
else
|
|
retval = usb_serial_generic_open(port, NULL);
|
|
if (retval)
|
|
port->open_count = 0;
|
|
}
|
|
|
|
if (retval) {
|
|
err ("could not open USB console port");
|
|
return retval;
|
|
}
|
|
|
|
if (serial->type->set_termios) {
|
|
/* build up a fake tty structure so that the open call has something
|
|
* to look at to get the cflag value */
|
|
tty = kmalloc (sizeof (*tty), GFP_KERNEL);
|
|
if (!tty) {
|
|
err ("no more memory");
|
|
return -ENOMEM;
|
|
}
|
|
termios = kmalloc (sizeof (*termios), GFP_KERNEL);
|
|
if (!termios) {
|
|
err ("no more memory");
|
|
kfree (tty);
|
|
return -ENOMEM;
|
|
}
|
|
memset (tty, 0x00, sizeof(*tty));
|
|
memset (termios, 0x00, sizeof(*termios));
|
|
termios->c_cflag = cflag;
|
|
tty->termios = termios;
|
|
port->tty = tty;
|
|
|
|
/* set up the initial termios settings */
|
|
serial->type->set_termios(port, NULL);
|
|
port->tty = NULL;
|
|
kfree (termios);
|
|
kfree (tty);
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
static void usb_console_write(struct console *co, const char *buf, unsigned count)
|
|
{
|
|
static struct usbcons_info *info = &usbcons_info;
|
|
struct usb_serial_port *port = info->port;
|
|
struct usb_serial *serial;
|
|
int retval = -ENODEV;
|
|
|
|
if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED)
|
|
return;
|
|
serial = port->serial;
|
|
|
|
if (count == 0)
|
|
return;
|
|
|
|
dbg("%s - port %d, %d byte(s)", __FUNCTION__, port->number, count);
|
|
|
|
if (!port->open_count) {
|
|
dbg ("%s - port not opened", __FUNCTION__);
|
|
return;
|
|
}
|
|
|
|
while (count) {
|
|
unsigned int i;
|
|
unsigned int lf;
|
|
/* search for LF so we can insert CR if necessary */
|
|
for (i=0, lf=0 ; i < count ; i++) {
|
|
if (*(buf + i) == 10) {
|
|
lf = 1;
|
|
i++;
|
|
break;
|
|
}
|
|
}
|
|
/* pass on to the driver specific version of this function if it is available */
|
|
if (serial->type->write)
|
|
retval = serial->type->write(port, buf, i);
|
|
else
|
|
retval = usb_serial_generic_write(port, buf, i);
|
|
dbg("%s - return value : %d", __FUNCTION__, retval);
|
|
if (lf) {
|
|
/* append CR after LF */
|
|
unsigned char cr = 13;
|
|
if (serial->type->write)
|
|
retval = serial->type->write(port, &cr, 1);
|
|
else
|
|
retval = usb_serial_generic_write(port, &cr, 1);
|
|
dbg("%s - return value : %d", __FUNCTION__, retval);
|
|
}
|
|
buf += i;
|
|
count -= i;
|
|
}
|
|
}
|
|
|
|
static struct console usbcons = {
|
|
.name = "ttyUSB",
|
|
.write = usb_console_write,
|
|
.setup = usb_console_setup,
|
|
.flags = CON_PRINTBUFFER,
|
|
.index = -1,
|
|
};
|
|
|
|
void usb_serial_console_disconnect(struct usb_serial *serial)
|
|
{
|
|
if (serial && serial->port && serial->port[0] && serial->port[0] == usbcons_info.port) {
|
|
usb_serial_console_exit();
|
|
usb_serial_put(serial);
|
|
}
|
|
}
|
|
|
|
void usb_serial_console_init (int serial_debug, int minor)
|
|
{
|
|
debug = serial_debug;
|
|
|
|
if (minor == 0) {
|
|
/*
|
|
* Call register_console() if this is the first device plugged
|
|
* in. If we call it earlier, then the callback to
|
|
* console_setup() will fail, as there is not a device seen by
|
|
* the USB subsystem yet.
|
|
*/
|
|
/*
|
|
* Register console.
|
|
* NOTES:
|
|
* console_setup() is called (back) immediately (from register_console).
|
|
* console_write() is called immediately from register_console iff
|
|
* CON_PRINTBUFFER is set in flags.
|
|
*/
|
|
dbg ("registering the USB serial console.");
|
|
register_console(&usbcons);
|
|
}
|
|
}
|
|
|
|
void usb_serial_console_exit (void)
|
|
{
|
|
if (usbcons_info.port) {
|
|
unregister_console(&usbcons);
|
|
if (usbcons_info.port->open_count)
|
|
usbcons_info.port->open_count--;
|
|
usbcons_info.port = NULL;
|
|
}
|
|
}
|
|
|