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846 giacomo 1
/*
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 * USB Serial Console driver
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 *
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 * Copyright (C) 2001 - 2002 Greg Kroah-Hartman (greg@kroah.com)
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 *
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 *      This program is free software; you can redistribute it and/or
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 *      modify it under the terms of the GNU General Public License version
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 *      2 as published by the Free Software Foundation.
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 *
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 * Thanks to Randy Dunlap for the original version of this code.
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 *
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 */
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#include <linuxcomp.h>
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#include <linux/config.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/tty.h>
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#include <linux/console.h>
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#include <linux/usb.h>
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static int debug;
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#include "usb-serial.h"
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struct usbcons_info {
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        int                     magic;
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        int                     break_flag;
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        struct usb_serial_port  *port;
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};
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static struct usbcons_info usbcons_info;
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static struct console usbcons;
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/*
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 * ------------------------------------------------------------
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 * USB Serial console driver
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 *
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 * Much of the code here is copied from drivers/char/serial.c
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 * and implements a phony serial console in the same way that
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 * serial.c does so that in case some software queries it,
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 * it will get the same results.
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 *
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 * Things that are different from the way the serial port code
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 * does things, is that we call the lower level usb-serial
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 * driver code to initialize the device, and we set the initial
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 * console speeds based on the command line arguments.
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 * ------------------------------------------------------------
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 */
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/*
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 * The parsing of the command line works exactly like the
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 * serial.c code, except that the specifier is "ttyUSB" instead
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 * of "ttyS".
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 */
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static int __init usb_console_setup(struct console *co, char *options)
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{
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        struct usbcons_info *info = &usbcons_info;
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        int baud = 9600;
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        int bits = 8;
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        int parity = 'n';
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        int doflow = 0;
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        int cflag = CREAD | HUPCL | CLOCAL;
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        char *s;
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        struct usb_serial *serial;
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        struct usb_serial_port *port;
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        int retval = 0;
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        struct tty_struct *tty;
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        struct termios *termios;
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        dbg ("%s", __FUNCTION__);
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        if (options) {
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                baud = simple_strtoul(options, NULL, 10);
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                s = options;
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                while (*s >= '0' && *s <= '9')
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                        s++;
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                if (*s)
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                        parity = *s++;
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                if (*s)
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                        bits   = *s++ - '0';
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                if (*s)
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                        doflow = (*s++ == 'r');
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        }
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        /* build a cflag setting */
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        switch (baud) {
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                case 1200:
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                        cflag |= B1200;
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                        break;
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                case 2400:
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                        cflag |= B2400;
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                        break;
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                case 4800:
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                        cflag |= B4800;
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                        break;
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                case 19200:
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                        cflag |= B19200;
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                        break;
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                case 38400:
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                        cflag |= B38400;
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                        break;
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                case 57600:
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                        cflag |= B57600;
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                        break;
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                case 115200:
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                        cflag |= B115200;
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                        break;
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                case 9600:
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                default:
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                        cflag |= B9600;
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                        /*
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                         * Set this to a sane value to prevent a divide error
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                         */
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                        baud  = 9600;
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                        break;
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        }
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        switch (bits) {
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                case 7:
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                        cflag |= CS7;
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                        break;
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                default:
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                case 8:
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                        cflag |= CS8;
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                        break;
129
        }
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        switch (parity) {
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                case 'o': case 'O':
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                        cflag |= PARODD;
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                        break;
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                case 'e': case 'E':
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                        cflag |= PARENB;
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                        break;
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        }
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        co->cflag = cflag;
139
 
140
        /* grab the first serial port that happens to be connected */
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        serial = usb_serial_get_by_index(0);
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        if (serial_paranoia_check (serial, __FUNCTION__)) {
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                /* no device is connected yet, sorry :( */
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                err ("No USB device connected to ttyUSB0");
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                return -ENODEV;
146
        }
147
 
148
        port = serial->port[0];
149
        port->tty = NULL;
150
 
151
        info->port = port;
152
 
153
        ++port->open_count;
154
        if (port->open_count == 1) {
155
                /* only call the device specific open if this
156
                 * is the first time the port is opened */
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                if (serial->type->open)
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                        retval = serial->type->open(port, NULL);
159
                else
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                        retval = usb_serial_generic_open(port, NULL);
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                if (retval)
162
                        port->open_count = 0;
163
        }
164
 
165
        if (retval) {
166
                err ("could not open USB console port");
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                return retval;
168
        }
169
 
170
        if (serial->type->set_termios) {
171
                /* build up a fake tty structure so that the open call has something
172
                 * to look at to get the cflag value */
173
                tty = kmalloc (sizeof (*tty), GFP_KERNEL);
174
                if (!tty) {
175
                        err ("no more memory");
176
                        return -ENOMEM;
177
                }
178
                termios = kmalloc (sizeof (*termios), GFP_KERNEL);
179
                if (!termios) {
180
                        err ("no more memory");
181
                        kfree (tty);
182
                        return -ENOMEM;
183
                }
184
                memset (tty, 0x00, sizeof(*tty));
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                memset (termios, 0x00, sizeof(*termios));
186
                termios->c_cflag = cflag;
187
                tty->termios = termios;
188
                port->tty = tty;
189
 
190
                /* set up the initial termios settings */
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                serial->type->set_termios(port, NULL);
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                port->tty = NULL;
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                kfree (termios);
194
                kfree (tty);
195
        }
196
 
197
        return retval;
198
}
199
 
200
static void usb_console_write(struct console *co, const char *buf, unsigned count)
201
{
202
        static struct usbcons_info *info = &usbcons_info;
203
        struct usb_serial_port *port = info->port;
204
        struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
205
        int retval = -ENODEV;
206
 
207
        if (!serial || !port)
208
                return;
209
 
210
        if (count == 0)
211
                return;
212
 
213
        dbg("%s - port %d, %d byte(s)", __FUNCTION__, port->number, count);
214
 
215
        if (!port->open_count) {
216
                dbg ("%s - port not opened", __FUNCTION__);
217
                goto exit;
218
        }
219
 
220
        /* pass on to the driver specific version of this function if it is available */
221
        if (serial->type->write)
222
                retval = serial->type->write(port, 0, buf, count);
223
        else
224
                retval = usb_serial_generic_write(port, 0, buf, count);
225
 
226
exit:
227
        dbg("%s - return value (if we had one): %d", __FUNCTION__, retval);
228
}
229
 
230
static struct console usbcons = {
231
        .name =         "ttyUSB",
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        .write =        usb_console_write,
233
        .setup =        usb_console_setup,
234
        .flags =        CON_PRINTBUFFER,
235
        .index =        -1,
236
};
237
 
238
void usb_serial_console_init (int serial_debug, int minor)
239
{
240
        debug = serial_debug;
241
 
242
        if (minor == 0) {
243
                /*
244
                 * Call register_console() if this is the first device plugged
245
                 * in.  If we call it earlier, then the callback to
246
                 * console_setup() will fail, as there is not a device seen by
247
                 * the USB subsystem yet.
248
                 */
249
                /*
250
                 * Register console.
251
                 * NOTES:
252
                 * console_setup() is called (back) immediately (from register_console).
253
                 * console_write() is called immediately from register_console iff
254
                 * CON_PRINTBUFFER is set in flags.
255
                 */
256
                dbg ("registering the USB serial console.");
257
                register_console(&usbcons);
258
        }
259
}
260
 
261
void usb_serial_console_exit (void)
262
{
263
        unregister_console(&usbcons);
264
}
265