2 * USB Serial Console driver
4 * Copyright (C) 2001 - 2002 Greg Kroah-Hartman (greg@kroah.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version
8 * 2 as published by the Free Software Foundation.
10 * Thanks to Randy Dunlap for the original version of this code.
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/tty.h>
18 #include <linux/console.h>
19 #include <linux/serial.h>
20 #include <linux/usb.h>
21 #include <linux/usb/serial.h>
28 struct usb_serial_port *port;
31 static struct usbcons_info usbcons_info;
32 static struct console usbcons;
35 * ------------------------------------------------------------
36 * USB Serial console driver
38 * Much of the code here is copied from drivers/char/serial.c
39 * and implements a phony serial console in the same way that
40 * serial.c does so that in case some software queries it,
41 * it will get the same results.
43 * Things that are different from the way the serial port code
44 * does things, is that we call the lower level usb-serial
45 * driver code to initialize the device, and we set the initial
46 * console speeds based on the command line arguments.
47 * ------------------------------------------------------------
52 * The parsing of the command line works exactly like the
53 * serial.c code, except that the specifier is "ttyUSB" instead
56 static int usb_console_setup(struct console *co, char *options)
58 struct usbcons_info *info = &usbcons_info;
63 int cflag = CREAD | HUPCL | CLOCAL;
65 struct usb_serial *serial;
66 struct usb_serial_port *port;
68 struct tty_struct *tty = NULL;
69 struct ktermios *termios = NULL, dummy;
74 baud = simple_strtoul(options, NULL, 10);
76 while (*s >= '0' && *s <= '9')
83 doflow = (*s++ == 'r');
110 * no need to check the index here: if the index is wrong, console
113 serial = usb_serial_get_by_index(co->index);
114 if (serial == NULL) {
115 /* no device is connected yet, sorry :( */
116 err("No USB device connected to ttyUSB%i", co->index);
120 retval = usb_autopm_get_interface(serial->interface);
122 goto error_get_interface;
124 port = serial->port[co->index - serial->minor];
125 tty_port_tty_set(&port->port, NULL);
130 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags)) {
131 if (serial->type->set_termios) {
133 * allocate a fake tty so the driver can initialize
134 * the termios structure, then later call set_termios to
135 * configure according to command line arguments
137 tty = kzalloc(sizeof(*tty), GFP_KERNEL);
140 err("no more memory");
141 goto reset_open_count;
143 kref_init(&tty->kref);
144 termios = kzalloc(sizeof(*termios), GFP_KERNEL);
147 err("no more memory");
150 memset(&dummy, 0, sizeof(struct ktermios));
151 tty->termios = termios;
152 tty_port_tty_set(&port->port, tty);
155 /* only call the device specific open if this
156 * is the first time the port is opened */
157 if (serial->type->open)
158 retval = serial->type->open(NULL, port);
160 retval = usb_serial_generic_open(NULL, port);
163 err("could not open USB console port");
167 if (serial->type->set_termios) {
168 termios->c_cflag = cflag;
169 tty_termios_encode_baud_rate(termios, baud, baud);
170 serial->type->set_termios(tty, port, &dummy);
172 tty_port_tty_set(&port->port, NULL);
176 set_bit(ASYNCB_INITIALIZED, &port->port.flags);
178 /* Now that any required fake tty operations are completed restore
179 * the tty port count */
181 /* The console is special in terms of closing the device so
182 * indicate this port is now acting as a system console. */
184 port->port.console = 1;
186 mutex_unlock(&serial->disc_mutex);
191 tty_port_tty_set(&port->port, NULL);
195 port->port.count = 0;
196 usb_autopm_put_interface(serial->interface);
198 usb_serial_put(serial);
199 mutex_unlock(&serial->disc_mutex);
203 static void usb_console_write(struct console *co,
204 const char *buf, unsigned count)
206 static struct usbcons_info *info = &usbcons_info;
207 struct usb_serial_port *port = info->port;
208 struct usb_serial *serial;
209 int retval = -ENODEV;
211 if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED)
213 serial = port->serial;
218 dbg("%s - port %d, %d byte(s)", __func__, port->number, count);
220 if (!port->console) {
221 dbg("%s - port not opened", __func__);
228 /* search for LF so we can insert CR if necessary */
229 for (i = 0, lf = 0 ; i < count ; i++) {
230 if (*(buf + i) == 10) {
236 /* pass on to the driver specific version of this function if
238 if (serial->type->write)
239 retval = serial->type->write(NULL, port, buf, i);
241 retval = usb_serial_generic_write(NULL, port, buf, i);
242 dbg("%s - return value : %d", __func__, retval);
244 /* append CR after LF */
245 unsigned char cr = 13;
246 if (serial->type->write)
247 retval = serial->type->write(NULL,
250 retval = usb_serial_generic_write(NULL,
252 dbg("%s - return value : %d", __func__, retval);
259 static struct tty_driver *usb_console_device(struct console *co, int *index)
261 struct tty_driver **p = (struct tty_driver **)co->data;
270 static struct console usbcons = {
272 .write = usb_console_write,
273 .device = usb_console_device,
274 .setup = usb_console_setup,
275 .flags = CON_PRINTBUFFER,
277 .data = &usb_serial_tty_driver,
280 void usb_serial_console_disconnect(struct usb_serial *serial)
282 if (serial && serial->port && serial->port[0]
283 && serial->port[0] == usbcons_info.port) {
284 usb_serial_console_exit();
285 usb_serial_put(serial);
289 void usb_serial_console_init(int serial_debug, int minor)
291 debug = serial_debug;
295 * Call register_console() if this is the first device plugged
296 * in. If we call it earlier, then the callback to
297 * console_setup() will fail, as there is not a device seen by
298 * the USB subsystem yet.
303 * console_setup() is called (back) immediately (from
304 * register_console). console_write() is called immediately
305 * from register_console iff CON_PRINTBUFFER is set in flags.
307 dbg("registering the USB serial console.");
308 register_console(&usbcons);
312 void usb_serial_console_exit(void)
314 if (usbcons_info.port) {
315 unregister_console(&usbcons);
316 usbcons_info.port->console = 0;
317 usbcons_info.port = NULL;