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 * ------------------------------------------------------------
50 static const struct tty_operations usb_console_fake_tty_ops = {
54 * The parsing of the command line works exactly like the
55 * serial.c code, except that the specifier is "ttyUSB" instead
58 static int usb_console_setup(struct console *co, char *options)
60 struct usbcons_info *info = &usbcons_info;
65 int cflag = CREAD | HUPCL | CLOCAL;
67 struct usb_serial *serial;
68 struct usb_serial_port *port;
70 struct tty_struct *tty = NULL;
71 struct ktermios dummy;
76 baud = simple_strtoul(options, NULL, 10);
78 while (*s >= '0' && *s <= '9')
85 doflow = (*s++ == 'r');
112 * no need to check the index here: if the index is wrong, console
115 serial = usb_serial_get_by_index(co->index);
116 if (serial == NULL) {
117 /* no device is connected yet, sorry :( */
118 err("No USB device connected to ttyUSB%i", co->index);
122 retval = usb_autopm_get_interface(serial->interface);
124 goto error_get_interface;
126 port = serial->port[co->index - serial->minor];
127 tty_port_tty_set(&port->port, NULL);
132 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags)) {
133 if (serial->type->set_termios) {
135 * allocate a fake tty so the driver can initialize
136 * the termios structure, then later call set_termios to
137 * configure according to command line arguments
139 tty = kzalloc(sizeof(*tty), GFP_KERNEL);
142 err("no more memory");
143 goto reset_open_count;
145 kref_init(&tty->kref);
146 tty->driver = usb_serial_tty_driver;
147 tty->index = co->index;
148 INIT_LIST_HEAD(&tty->tty_files);
149 kref_get(&tty->driver->kref);
150 tty->ops = &usb_console_fake_tty_ops;
151 if (tty_init_termios(tty)) {
153 err("no more memory");
156 tty_port_tty_set(&port->port, tty);
159 /* only call the device specific open if this
160 * is the first time the port is opened */
161 if (serial->type->open)
162 retval = serial->type->open(NULL, port);
164 retval = usb_serial_generic_open(NULL, port);
167 err("could not open USB console port");
171 if (serial->type->set_termios) {
172 tty->termios->c_cflag = cflag;
173 tty_termios_encode_baud_rate(tty->termios, baud, baud);
174 memset(&dummy, 0, sizeof(struct ktermios));
175 serial->type->set_termios(tty, port, &dummy);
177 tty_port_tty_set(&port->port, NULL);
180 set_bit(ASYNCB_INITIALIZED, &port->port.flags);
182 /* Now that any required fake tty operations are completed restore
183 * the tty port count */
185 /* The console is special in terms of closing the device so
186 * indicate this port is now acting as a system console. */
187 port->port.console = 1;
189 mutex_unlock(&serial->disc_mutex);
193 tty_port_tty_set(&port->port, NULL);
197 port->port.count = 0;
198 usb_autopm_put_interface(serial->interface);
200 usb_serial_put(serial);
201 mutex_unlock(&serial->disc_mutex);
205 static void usb_console_write(struct console *co,
206 const char *buf, unsigned count)
208 static struct usbcons_info *info = &usbcons_info;
209 struct usb_serial_port *port = info->port;
210 struct usb_serial *serial;
211 int retval = -ENODEV;
213 if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED)
215 serial = port->serial;
220 dbg("%s - port %d, %d byte(s)", __func__, port->number, count);
222 if (!port->port.console) {
223 dbg("%s - port not opened", __func__);
230 /* search for LF so we can insert CR if necessary */
231 for (i = 0, lf = 0 ; i < count ; i++) {
232 if (*(buf + i) == 10) {
238 /* pass on to the driver specific version of this function if
240 if (serial->type->write)
241 retval = serial->type->write(NULL, port, buf, i);
243 retval = usb_serial_generic_write(NULL, port, buf, i);
244 dbg("%s - return value : %d", __func__, retval);
246 /* append CR after LF */
247 unsigned char cr = 13;
248 if (serial->type->write)
249 retval = serial->type->write(NULL,
252 retval = usb_serial_generic_write(NULL,
254 dbg("%s - return value : %d", __func__, retval);
261 static struct tty_driver *usb_console_device(struct console *co, int *index)
263 struct tty_driver **p = (struct tty_driver **)co->data;
272 static struct console usbcons = {
274 .write = usb_console_write,
275 .device = usb_console_device,
276 .setup = usb_console_setup,
277 .flags = CON_PRINTBUFFER,
279 .data = &usb_serial_tty_driver,
282 void usb_serial_console_disconnect(struct usb_serial *serial)
284 if (serial && serial->port && serial->port[0]
285 && serial->port[0] == usbcons_info.port) {
286 usb_serial_console_exit();
287 usb_serial_put(serial);
291 void usb_serial_console_init(int serial_debug, int minor)
293 debug = serial_debug;
297 * Call register_console() if this is the first device plugged
298 * in. If we call it earlier, then the callback to
299 * console_setup() will fail, as there is not a device seen by
300 * the USB subsystem yet.
305 * console_setup() is called (back) immediately (from
306 * register_console). console_write() is called immediately
307 * from register_console iff CON_PRINTBUFFER is set in flags.
309 dbg("registering the USB serial console.");
310 register_console(&usbcons);
314 void usb_serial_console_exit(void)
316 if (usbcons_info.port) {
317 unregister_console(&usbcons);
318 usbcons_info.port->port.console = 0;
319 usbcons_info.port = NULL;