1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Belkin USB Serial Adapter Driver
4 *
5 * Copyright (C) 2000 William Greathouse (wgreathouse@smva.com)
6 * Copyright (C) 2000-2001 Greg Kroah-Hartman (greg@kroah.com)
7 * Copyright (C) 2010 Johan Hovold (jhovold@gmail.com)
8 *
9 * This program is largely derived from work by the linux-usb group
10 * and associated source files. Please see the usb/serial files for
11 * individual credits and copyrights.
12 *
13 * See Documentation/usb/usb-serial.rst for more information on using this
14 * driver
15 *
16 * TODO:
17 * -- Add true modem control line query capability. Currently we track the
18 * states reported by the interrupt and the states we request.
19 * -- Add support for flush commands
20 */
21
22 #include <linux/kernel.h>
23 #include <linux/errno.h>
24 #include <linux/slab.h>
25 #include <linux/tty.h>
26 #include <linux/tty_driver.h>
27 #include <linux/tty_flip.h>
28 #include <linux/module.h>
29 #include <linux/spinlock.h>
30 #include <linux/uaccess.h>
31 #include <linux/usb.h>
32 #include <linux/usb/serial.h>
33 #include "belkin_sa.h"
34
35 #define DRIVER_AUTHOR "William Greathouse <wgreathouse@smva.com>"
36 #define DRIVER_DESC "USB Belkin Serial converter driver"
37
38 /* function prototypes for a Belkin USB Serial Adapter F5U103 */
39 static int belkin_sa_port_probe(struct usb_serial_port *port);
40 static void belkin_sa_port_remove(struct usb_serial_port *port);
41 static int belkin_sa_open(struct tty_struct *tty,
42 struct usb_serial_port *port);
43 static void belkin_sa_close(struct usb_serial_port *port);
44 static void belkin_sa_read_int_callback(struct urb *urb);
45 static void belkin_sa_process_read_urb(struct urb *urb);
46 static void belkin_sa_set_termios(struct tty_struct *tty,
47 struct usb_serial_port *port,
48 const struct ktermios *old_termios);
49 static int belkin_sa_break_ctl(struct tty_struct *tty, int break_state);
50 static int belkin_sa_tiocmget(struct tty_struct *tty);
51 static int belkin_sa_tiocmset(struct tty_struct *tty,
52 unsigned int set, unsigned int clear);
53
54
55 static const struct usb_device_id id_table[] = {
56 { USB_DEVICE(BELKIN_SA_VID, BELKIN_SA_PID) },
57 { USB_DEVICE(BELKIN_OLD_VID, BELKIN_OLD_PID) },
58 { USB_DEVICE(PERACOM_VID, PERACOM_PID) },
59 { USB_DEVICE(GOHUBS_VID, GOHUBS_PID) },
60 { USB_DEVICE(GOHUBS_VID, HANDYLINK_PID) },
61 { USB_DEVICE(BELKIN_DOCKSTATION_VID, BELKIN_DOCKSTATION_PID) },
62 { } /* Terminating entry */
63 };
64 MODULE_DEVICE_TABLE(usb, id_table);
65
66 /* All of the device info needed for the serial converters */
67 static struct usb_serial_driver belkin_device = {
68 .driver = {
69 .name = "belkin",
70 },
71 .description = "Belkin / Peracom / GoHubs USB Serial Adapter",
72 .id_table = id_table,
73 .num_ports = 1,
74 .open = belkin_sa_open,
75 .close = belkin_sa_close,
76 .read_int_callback = belkin_sa_read_int_callback,
77 .process_read_urb = belkin_sa_process_read_urb,
78 .set_termios = belkin_sa_set_termios,
79 .break_ctl = belkin_sa_break_ctl,
80 .tiocmget = belkin_sa_tiocmget,
81 .tiocmset = belkin_sa_tiocmset,
82 .port_probe = belkin_sa_port_probe,
83 .port_remove = belkin_sa_port_remove,
84 };
85
86 static struct usb_serial_driver * const serial_drivers[] = {
87 &belkin_device, NULL
88 };
89
90 struct belkin_sa_private {
91 spinlock_t lock;
92 unsigned long control_state;
93 unsigned char last_lsr;
94 unsigned char last_msr;
95 int bad_flow_control;
96 };
97
98
99 /*
100 * ***************************************************************************
101 * Belkin USB Serial Adapter F5U103 specific driver functions
102 * ***************************************************************************
103 */
104
105 #define WDR_TIMEOUT 5000 /* default urb timeout */
106
107 /* assumes that struct usb_serial *serial is available */
108 #define BSA_USB_CMD(c, v) usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), \
109 (c), BELKIN_SA_SET_REQUEST_TYPE, \
110 (v), 0, NULL, 0, WDR_TIMEOUT)
111
belkin_sa_port_probe(struct usb_serial_port * port)112 static int belkin_sa_port_probe(struct usb_serial_port *port)
113 {
114 struct usb_device *dev = port->serial->dev;
115 struct belkin_sa_private *priv;
116
117 priv = kmalloc(sizeof(struct belkin_sa_private), GFP_KERNEL);
118 if (!priv)
119 return -ENOMEM;
120
121 spin_lock_init(&priv->lock);
122 priv->control_state = 0;
123 priv->last_lsr = 0;
124 priv->last_msr = 0;
125 /* see comments at top of file */
126 priv->bad_flow_control =
127 (le16_to_cpu(dev->descriptor.bcdDevice) <= 0x0206) ? 1 : 0;
128 dev_info(&dev->dev, "bcdDevice: %04x, bfc: %d\n",
129 le16_to_cpu(dev->descriptor.bcdDevice),
130 priv->bad_flow_control);
131
132 usb_set_serial_port_data(port, priv);
133
134 return 0;
135 }
136
belkin_sa_port_remove(struct usb_serial_port * port)137 static void belkin_sa_port_remove(struct usb_serial_port *port)
138 {
139 struct belkin_sa_private *priv;
140
141 priv = usb_get_serial_port_data(port);
142 kfree(priv);
143 }
144
belkin_sa_open(struct tty_struct * tty,struct usb_serial_port * port)145 static int belkin_sa_open(struct tty_struct *tty,
146 struct usb_serial_port *port)
147 {
148 int retval;
149
150 retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
151 if (retval) {
152 dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
153 return retval;
154 }
155
156 retval = usb_serial_generic_open(tty, port);
157 if (retval)
158 usb_kill_urb(port->interrupt_in_urb);
159
160 return retval;
161 }
162
belkin_sa_close(struct usb_serial_port * port)163 static void belkin_sa_close(struct usb_serial_port *port)
164 {
165 usb_serial_generic_close(port);
166 usb_kill_urb(port->interrupt_in_urb);
167 }
168
belkin_sa_read_int_callback(struct urb * urb)169 static void belkin_sa_read_int_callback(struct urb *urb)
170 {
171 struct usb_serial_port *port = urb->context;
172 struct belkin_sa_private *priv;
173 unsigned char *data = urb->transfer_buffer;
174 int retval;
175 int status = urb->status;
176 unsigned long flags;
177
178 switch (status) {
179 case 0:
180 /* success */
181 break;
182 case -ECONNRESET:
183 case -ENOENT:
184 case -ESHUTDOWN:
185 /* this urb is terminated, clean up */
186 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
187 __func__, status);
188 return;
189 default:
190 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
191 __func__, status);
192 goto exit;
193 }
194
195 usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
196
197 /* Handle known interrupt data */
198 /* ignore data[0] and data[1] */
199
200 priv = usb_get_serial_port_data(port);
201 spin_lock_irqsave(&priv->lock, flags);
202 priv->last_msr = data[BELKIN_SA_MSR_INDEX];
203
204 /* Record Control Line states */
205 if (priv->last_msr & BELKIN_SA_MSR_DSR)
206 priv->control_state |= TIOCM_DSR;
207 else
208 priv->control_state &= ~TIOCM_DSR;
209
210 if (priv->last_msr & BELKIN_SA_MSR_CTS)
211 priv->control_state |= TIOCM_CTS;
212 else
213 priv->control_state &= ~TIOCM_CTS;
214
215 if (priv->last_msr & BELKIN_SA_MSR_RI)
216 priv->control_state |= TIOCM_RI;
217 else
218 priv->control_state &= ~TIOCM_RI;
219
220 if (priv->last_msr & BELKIN_SA_MSR_CD)
221 priv->control_state |= TIOCM_CD;
222 else
223 priv->control_state &= ~TIOCM_CD;
224
225 priv->last_lsr = data[BELKIN_SA_LSR_INDEX];
226 spin_unlock_irqrestore(&priv->lock, flags);
227 exit:
228 retval = usb_submit_urb(urb, GFP_ATOMIC);
229 if (retval)
230 dev_err(&port->dev, "%s - usb_submit_urb failed with "
231 "result %d\n", __func__, retval);
232 }
233
belkin_sa_process_read_urb(struct urb * urb)234 static void belkin_sa_process_read_urb(struct urb *urb)
235 {
236 struct usb_serial_port *port = urb->context;
237 struct belkin_sa_private *priv = usb_get_serial_port_data(port);
238 unsigned char *data = urb->transfer_buffer;
239 unsigned long flags;
240 unsigned char status;
241 char tty_flag;
242
243 /* Update line status */
244 tty_flag = TTY_NORMAL;
245
246 spin_lock_irqsave(&priv->lock, flags);
247 status = priv->last_lsr;
248 priv->last_lsr &= ~BELKIN_SA_LSR_ERR;
249 spin_unlock_irqrestore(&priv->lock, flags);
250
251 if (!urb->actual_length)
252 return;
253
254 if (status & BELKIN_SA_LSR_ERR) {
255 /* Break takes precedence over parity, which takes precedence
256 * over framing errors. */
257 if (status & BELKIN_SA_LSR_BI)
258 tty_flag = TTY_BREAK;
259 else if (status & BELKIN_SA_LSR_PE)
260 tty_flag = TTY_PARITY;
261 else if (status & BELKIN_SA_LSR_FE)
262 tty_flag = TTY_FRAME;
263 dev_dbg(&port->dev, "tty_flag = %d\n", tty_flag);
264
265 /* Overrun is special, not associated with a char. */
266 if (status & BELKIN_SA_LSR_OE)
267 tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
268 }
269
270 tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
271 urb->actual_length);
272 tty_flip_buffer_push(&port->port);
273 }
274
belkin_sa_set_termios(struct tty_struct * tty,struct usb_serial_port * port,const struct ktermios * old_termios)275 static void belkin_sa_set_termios(struct tty_struct *tty,
276 struct usb_serial_port *port,
277 const struct ktermios *old_termios)
278 {
279 struct usb_serial *serial = port->serial;
280 struct belkin_sa_private *priv = usb_get_serial_port_data(port);
281 unsigned int iflag;
282 unsigned int cflag;
283 unsigned int old_iflag = 0;
284 unsigned int old_cflag = 0;
285 __u16 urb_value = 0; /* Will hold the new flags */
286 unsigned long flags;
287 unsigned long control_state;
288 int bad_flow_control;
289 speed_t baud;
290 struct ktermios *termios = &tty->termios;
291
292 iflag = termios->c_iflag;
293 cflag = termios->c_cflag;
294
295 termios->c_cflag &= ~CMSPAR;
296
297 /* get a local copy of the current port settings */
298 spin_lock_irqsave(&priv->lock, flags);
299 control_state = priv->control_state;
300 bad_flow_control = priv->bad_flow_control;
301 spin_unlock_irqrestore(&priv->lock, flags);
302
303 old_iflag = old_termios->c_iflag;
304 old_cflag = old_termios->c_cflag;
305
306 /* Set the baud rate */
307 if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
308 /* reassert DTR and (maybe) RTS on transition from B0 */
309 if ((old_cflag & CBAUD) == B0) {
310 control_state |= (TIOCM_DTR|TIOCM_RTS);
311 if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 1) < 0)
312 dev_err(&port->dev, "Set DTR error\n");
313 /* don't set RTS if using hardware flow control */
314 if (!(old_cflag & CRTSCTS))
315 if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST
316 , 1) < 0)
317 dev_err(&port->dev, "Set RTS error\n");
318 }
319 }
320
321 baud = tty_get_baud_rate(tty);
322 if (baud) {
323 urb_value = BELKIN_SA_BAUD(baud);
324 /* Clip to maximum speed */
325 if (urb_value == 0)
326 urb_value = 1;
327 /* Turn it back into a resulting real baud rate */
328 baud = BELKIN_SA_BAUD(urb_value);
329
330 /* Report the actual baud rate back to the caller */
331 tty_encode_baud_rate(tty, baud, baud);
332 if (BSA_USB_CMD(BELKIN_SA_SET_BAUDRATE_REQUEST, urb_value) < 0)
333 dev_err(&port->dev, "Set baudrate error\n");
334 } else {
335 /* Disable flow control */
336 if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST,
337 BELKIN_SA_FLOW_NONE) < 0)
338 dev_err(&port->dev, "Disable flowcontrol error\n");
339 /* Drop RTS and DTR */
340 control_state &= ~(TIOCM_DTR | TIOCM_RTS);
341 if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 0) < 0)
342 dev_err(&port->dev, "DTR LOW error\n");
343 if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, 0) < 0)
344 dev_err(&port->dev, "RTS LOW error\n");
345 }
346
347 /* set the parity */
348 if ((cflag ^ old_cflag) & (PARENB | PARODD)) {
349 if (cflag & PARENB)
350 urb_value = (cflag & PARODD) ? BELKIN_SA_PARITY_ODD
351 : BELKIN_SA_PARITY_EVEN;
352 else
353 urb_value = BELKIN_SA_PARITY_NONE;
354 if (BSA_USB_CMD(BELKIN_SA_SET_PARITY_REQUEST, urb_value) < 0)
355 dev_err(&port->dev, "Set parity error\n");
356 }
357
358 /* set the number of data bits */
359 if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
360 urb_value = BELKIN_SA_DATA_BITS(tty_get_char_size(cflag));
361 if (BSA_USB_CMD(BELKIN_SA_SET_DATA_BITS_REQUEST, urb_value) < 0)
362 dev_err(&port->dev, "Set data bits error\n");
363 }
364
365 /* set the number of stop bits */
366 if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
367 urb_value = (cflag & CSTOPB) ? BELKIN_SA_STOP_BITS(2)
368 : BELKIN_SA_STOP_BITS(1);
369 if (BSA_USB_CMD(BELKIN_SA_SET_STOP_BITS_REQUEST,
370 urb_value) < 0)
371 dev_err(&port->dev, "Set stop bits error\n");
372 }
373
374 /* Set flow control */
375 if (((iflag ^ old_iflag) & (IXOFF | IXON)) ||
376 ((cflag ^ old_cflag) & CRTSCTS)) {
377 urb_value = 0;
378 if ((iflag & IXOFF) || (iflag & IXON))
379 urb_value |= (BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
380 else
381 urb_value &= ~(BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
382
383 if (cflag & CRTSCTS)
384 urb_value |= (BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
385 else
386 urb_value &= ~(BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
387
388 if (bad_flow_control)
389 urb_value &= ~(BELKIN_SA_FLOW_IRTS);
390
391 if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST, urb_value) < 0)
392 dev_err(&port->dev, "Set flow control error\n");
393 }
394
395 /* save off the modified port settings */
396 spin_lock_irqsave(&priv->lock, flags);
397 priv->control_state = control_state;
398 spin_unlock_irqrestore(&priv->lock, flags);
399 }
400
belkin_sa_break_ctl(struct tty_struct * tty,int break_state)401 static int belkin_sa_break_ctl(struct tty_struct *tty, int break_state)
402 {
403 struct usb_serial_port *port = tty->driver_data;
404 struct usb_serial *serial = port->serial;
405 int ret;
406
407 ret = BSA_USB_CMD(BELKIN_SA_SET_BREAK_REQUEST, break_state ? 1 : 0);
408 if (ret < 0) {
409 dev_err(&port->dev, "Set break_ctl %d\n", break_state);
410 return ret;
411 }
412
413 return 0;
414 }
415
belkin_sa_tiocmget(struct tty_struct * tty)416 static int belkin_sa_tiocmget(struct tty_struct *tty)
417 {
418 struct usb_serial_port *port = tty->driver_data;
419 struct belkin_sa_private *priv = usb_get_serial_port_data(port);
420 unsigned long control_state;
421 unsigned long flags;
422
423 spin_lock_irqsave(&priv->lock, flags);
424 control_state = priv->control_state;
425 spin_unlock_irqrestore(&priv->lock, flags);
426
427 return control_state;
428 }
429
belkin_sa_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)430 static int belkin_sa_tiocmset(struct tty_struct *tty,
431 unsigned int set, unsigned int clear)
432 {
433 struct usb_serial_port *port = tty->driver_data;
434 struct usb_serial *serial = port->serial;
435 struct belkin_sa_private *priv = usb_get_serial_port_data(port);
436 unsigned long control_state;
437 unsigned long flags;
438 int retval;
439 int rts = 0;
440 int dtr = 0;
441
442 spin_lock_irqsave(&priv->lock, flags);
443 control_state = priv->control_state;
444
445 if (set & TIOCM_RTS) {
446 control_state |= TIOCM_RTS;
447 rts = 1;
448 }
449 if (set & TIOCM_DTR) {
450 control_state |= TIOCM_DTR;
451 dtr = 1;
452 }
453 if (clear & TIOCM_RTS) {
454 control_state &= ~TIOCM_RTS;
455 rts = 0;
456 }
457 if (clear & TIOCM_DTR) {
458 control_state &= ~TIOCM_DTR;
459 dtr = 0;
460 }
461
462 priv->control_state = control_state;
463 spin_unlock_irqrestore(&priv->lock, flags);
464
465 retval = BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, rts);
466 if (retval < 0) {
467 dev_err(&port->dev, "Set RTS error %d\n", retval);
468 goto exit;
469 }
470
471 retval = BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, dtr);
472 if (retval < 0) {
473 dev_err(&port->dev, "Set DTR error %d\n", retval);
474 goto exit;
475 }
476 exit:
477 return retval;
478 }
479
480 module_usb_serial_driver(serial_drivers, id_table);
481
482 MODULE_AUTHOR(DRIVER_AUTHOR);
483 MODULE_DESCRIPTION(DRIVER_DESC);
484 MODULE_LICENSE("GPL");
485