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 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 printk(KERN_ERR "No USB device connected to ttyUSB%i\n",
121 retval = usb_autopm_get_interface(serial->interface);
123 goto error_get_interface;
125 port = serial->port[co->index - serial->minor];
126 tty_port_tty_set(&port->port, NULL);
131 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags)) {
132 if (serial->type->set_termios) {
134 * allocate a fake tty so the driver can initialize
135 * the termios structure, then later call set_termios to
136 * configure according to command line arguments
138 tty = kzalloc(sizeof(*tty), GFP_KERNEL);
141 dev_err(&port->dev, "no more memory\n");
142 goto reset_open_count;
144 kref_init(&tty->kref);
145 tty_port_tty_set(&port->port, tty);
146 tty->driver = usb_serial_tty_driver;
147 tty->index = co->index;
148 if (tty_init_termios(tty)) {
150 dev_err(&port->dev, "no more memory\n");
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 dev_err(&port->dev, "could not open USB console port\n");
167 if (serial->type->set_termios) {
168 tty->termios->c_cflag = cflag;
169 tty_termios_encode_baud_rate(tty->termios, baud, baud);
170 memset(&dummy, 0, sizeof(struct ktermios));
171 serial->type->set_termios(tty, port, &dummy);
173 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. */
183 port->port.console = 1;
185 mutex_unlock(&serial->disc_mutex);
189 tty_port_tty_set(&port->port, NULL);
193 port->port.count = 0;
194 usb_autopm_put_interface(serial->interface);
196 usb_serial_put(serial);
197 mutex_unlock(&serial->disc_mutex);
201 static void usb_console_write(struct console *co,
202 const char *buf, unsigned count)
204 static struct usbcons_info *info = &usbcons_info;
205 struct usb_serial_port *port = info->port;
206 struct usb_serial *serial;
207 int retval = -ENODEV;
209 if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED)
211 serial = port->serial;
216 dbg("%s - port %d, %d byte(s)", __func__, port->number, count);
218 if (!port->port.console) {
219 dbg("%s - port not opened", __func__);
226 /* search for LF so we can insert CR if necessary */
227 for (i = 0, lf = 0 ; i < count ; i++) {
228 if (*(buf + i) == 10) {
234 /* pass on to the driver specific version of this function if
236 if (serial->type->write)
237 retval = serial->type->write(NULL, port, buf, i);
239 retval = usb_serial_generic_write(NULL, port, buf, i);
240 dbg("%s - return value : %d", __func__, retval);
242 /* append CR after LF */
243 unsigned char cr = 13;
244 if (serial->type->write)
245 retval = serial->type->write(NULL,
248 retval = usb_serial_generic_write(NULL,
250 dbg("%s - return value : %d", __func__, retval);
257 static struct tty_driver *usb_console_device(struct console *co, int *index)
259 struct tty_driver **p = (struct tty_driver **)co->data;
268 static struct console usbcons = {
270 .write = usb_console_write,
271 .device = usb_console_device,
272 .setup = usb_console_setup,
273 .flags = CON_PRINTBUFFER,
275 .data = &usb_serial_tty_driver,
278 void usb_serial_console_disconnect(struct usb_serial *serial)
280 if (serial && serial->port && serial->port[0]
281 && serial->port[0] == usbcons_info.port) {
282 usb_serial_console_exit();
283 usb_serial_put(serial);
287 void usb_serial_console_init(int serial_debug, int minor)
289 debug = serial_debug;
293 * Call register_console() if this is the first device plugged
294 * in. If we call it earlier, then the callback to
295 * console_setup() will fail, as there is not a device seen by
296 * the USB subsystem yet.
301 * console_setup() is called (back) immediately (from
302 * register_console). console_write() is called immediately
303 * from register_console iff CON_PRINTBUFFER is set in flags.
305 dbg("registering the USB serial console.");
306 register_console(&usbcons);
310 void usb_serial_console_exit(void)
312 if (usbcons_info.port) {
313 unregister_console(&usbcons);
314 usbcons_info.port->port.console = 0;
315 usbcons_info.port = NULL;