diff options
Diffstat (limited to 'drivers/usb/serial/console.c')
| -rw-r--r-- | drivers/usb/serial/console.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/drivers/usb/serial/console.c b/drivers/usb/serial/console.c new file mode 100644 index 000000000000..167f8ec56131 --- /dev/null +++ b/drivers/usb/serial/console.c @@ -0,0 +1,264 @@ +/* + * 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 __init 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) + 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__); + goto exit; + } + + /* pass on to the driver specific version of this function if it is available */ + if (serial->type->write) + retval = serial->type->write(port, buf, count); + else + retval = usb_serial_generic_write(port, buf, count); + +exit: + dbg("%s - return value (if we had one): %d", __FUNCTION__, retval); +} + +static struct console usbcons = { + .name = "ttyUSB", + .write = usb_console_write, + .setup = usb_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + +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) +{ + unregister_console(&usbcons); +} + |