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 .owner = THIS_MODULE,
70 .name = "belkin",
71 },
72 .description = "Belkin / Peracom / GoHubs USB Serial Adapter",
73 .id_table = id_table,
74 .num_ports = 1,
75 .open = belkin_sa_open,
76 .close = belkin_sa_close,
77 .read_int_callback = belkin_sa_read_int_callback,
78 .process_read_urb = belkin_sa_process_read_urb,
79 .set_termios = belkin_sa_set_termios,
80 .break_ctl = belkin_sa_break_ctl,
81 .tiocmget = belkin_sa_tiocmget,
82 .tiocmset = belkin_sa_tiocmset,
83 .port_probe = belkin_sa_port_probe,
84 .port_remove = belkin_sa_port_remove,
85 };
86
87 static struct usb_serial_driver * const serial_drivers[] = {
88 &belkin_device, NULL
89 };
90
91 struct belkin_sa_private {
92 spinlock_t lock;
93 unsigned long control_state;
94 unsigned char last_lsr;
95 unsigned char last_msr;
96 int bad_flow_control;
97 };
98
99
100 /*
101 * ***************************************************************************
102 * Belkin USB Serial Adapter F5U103 specific driver functions
103 * ***************************************************************************
104 */
105
106 #define WDR_TIMEOUT 5000 /* default urb timeout */
107
108 /* assumes that struct usb_serial *serial is available */
109 #define BSA_USB_CMD(c, v) usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), \
110 (c), BELKIN_SA_SET_REQUEST_TYPE, \
111 (v), 0, NULL, 0, WDR_TIMEOUT)
112
belkin_sa_port_probe(struct usb_serial_port * port)113 static int belkin_sa_port_probe(struct usb_serial_port *port)
114 {
115 struct usb_device *dev = port->serial->dev;
116 struct belkin_sa_private *priv;
117
118 priv = kmalloc(sizeof(struct belkin_sa_private), GFP_KERNEL);
119 if (!priv)
120 return -ENOMEM;
121
122 spin_lock_init(&priv->lock);
123 priv->control_state = 0;
124 priv->last_lsr = 0;
125 priv->last_msr = 0;
126 /* see comments at top of file */
127 priv->bad_flow_control =
128 (le16_to_cpu(dev->descriptor.bcdDevice) <= 0x0206) ? 1 : 0;
129 dev_info(&dev->dev, "bcdDevice: %04x, bfc: %d\n",
130 le16_to_cpu(dev->descriptor.bcdDevice),
131 priv->bad_flow_control);
132
133 usb_set_serial_port_data(port, priv);
134
135 return 0;
136 }
137
belkin_sa_port_remove(struct usb_serial_port * port)138 static void belkin_sa_port_remove(struct usb_serial_port *port)
139 {
140 struct belkin_sa_private *priv;
141
142 priv = usb_get_serial_port_data(port);
143 kfree(priv);
144 }
145
belkin_sa_open(struct tty_struct * tty,struct usb_serial_port * port)146 static int belkin_sa_open(struct tty_struct *tty,
147 struct usb_serial_port *port)
148 {
149 int retval;
150
151 retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
152 if (retval) {
153 dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
154 return retval;
155 }
156
157 retval = usb_serial_generic_open(tty, port);
158 if (retval)
159 usb_kill_urb(port->interrupt_in_urb);
160
161 return retval;
162 }
163
belkin_sa_close(struct usb_serial_port * port)164 static void belkin_sa_close(struct usb_serial_port *port)
165 {
166 usb_serial_generic_close(port);
167 usb_kill_urb(port->interrupt_in_urb);
168 }
169
belkin_sa_read_int_callback(struct urb * urb)170 static void belkin_sa_read_int_callback(struct urb *urb)
171 {
172 struct usb_serial_port *port = urb->context;
173 struct belkin_sa_private *priv;
174 unsigned char *data = urb->transfer_buffer;
175 int retval;
176 int status = urb->status;
177 unsigned long flags;
178
179 switch (status) {
180 case 0:
181 /* success */
182 break;
183 case -ECONNRESET:
184 case -ENOENT:
185 case -ESHUTDOWN:
186 /* this urb is terminated, clean up */
187 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
188 __func__, status);
189 return;
190 default:
191 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
192 __func__, status);
193 goto exit;
194 }
195
196 usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
197
198 /* Handle known interrupt data */
199 /* ignore data[0] and data[1] */
200
201 priv = usb_get_serial_port_data(port);
202 spin_lock_irqsave(&priv->lock, flags);
203 priv->last_msr = data[BELKIN_SA_MSR_INDEX];
204
205 /* Record Control Line states */
206 if (priv->last_msr & BELKIN_SA_MSR_DSR)
207 priv->control_state |= TIOCM_DSR;
208 else
209 priv->control_state &= ~TIOCM_DSR;
210
211 if (priv->last_msr & BELKIN_SA_MSR_CTS)
212 priv->control_state |= TIOCM_CTS;
213 else
214 priv->control_state &= ~TIOCM_CTS;
215
216 if (priv->last_msr & BELKIN_SA_MSR_RI)
217 priv->control_state |= TIOCM_RI;
218 else
219 priv->control_state &= ~TIOCM_RI;
220
221 if (priv->last_msr & BELKIN_SA_MSR_CD)
222 priv->control_state |= TIOCM_CD;
223 else
224 priv->control_state &= ~TIOCM_CD;
225
226 priv->last_lsr = data[BELKIN_SA_LSR_INDEX];
227 spin_unlock_irqrestore(&priv->lock, flags);
228 exit:
229 retval = usb_submit_urb(urb, GFP_ATOMIC);
230 if (retval)
231 dev_err(&port->dev, "%s - usb_submit_urb failed with "
232 "result %d\n", __func__, retval);
233 }
234
belkin_sa_process_read_urb(struct urb * urb)235 static void belkin_sa_process_read_urb(struct urb *urb)
236 {
237 struct usb_serial_port *port = urb->context;
238 struct belkin_sa_private *priv = usb_get_serial_port_data(port);
239 unsigned char *data = urb->transfer_buffer;
240 unsigned long flags;
241 unsigned char status;
242 char tty_flag;
243
244 /* Update line status */
245 tty_flag = TTY_NORMAL;
246
247 spin_lock_irqsave(&priv->lock, flags);
248 status = priv->last_lsr;
249 priv->last_lsr &= ~BELKIN_SA_LSR_ERR;
250 spin_unlock_irqrestore(&priv->lock, flags);
251
252 if (!urb->actual_length)
253 return;
254
255 if (status & BELKIN_SA_LSR_ERR) {
256 /* Break takes precedence over parity, which takes precedence
257 * over framing errors. */
258 if (status & BELKIN_SA_LSR_BI)
259 tty_flag = TTY_BREAK;
260 else if (status & BELKIN_SA_LSR_PE)
261 tty_flag = TTY_PARITY;
262 else if (status & BELKIN_SA_LSR_FE)
263 tty_flag = TTY_FRAME;
264 dev_dbg(&port->dev, "tty_flag = %d\n", tty_flag);
265
266 /* Overrun is special, not associated with a char. */
267 if (status & BELKIN_SA_LSR_OE)
268 tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
269 }
270
271 tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
272 urb->actual_length);
273 tty_flip_buffer_push(&port->port);
274 }
275
belkin_sa_set_termios(struct tty_struct * tty,struct usb_serial_port * port,const struct ktermios * old_termios)276 static void belkin_sa_set_termios(struct tty_struct *tty,
277 struct usb_serial_port *port,
278 const struct ktermios *old_termios)
279 {
280 struct usb_serial *serial = port->serial;
281 struct belkin_sa_private *priv = usb_get_serial_port_data(port);
282 unsigned int iflag;
283 unsigned int cflag;
284 unsigned int old_iflag = 0;
285 unsigned int old_cflag = 0;
286 __u16 urb_value = 0; /* Will hold the new flags */
287 unsigned long flags;
288 unsigned long control_state;
289 int bad_flow_control;
290 speed_t baud;
291 struct ktermios *termios = &tty->termios;
292
293 iflag = termios->c_iflag;
294 cflag = termios->c_cflag;
295
296 termios->c_cflag &= ~CMSPAR;
297
298 /* get a local copy of the current port settings */
299 spin_lock_irqsave(&priv->lock, flags);
300 control_state = priv->control_state;
301 bad_flow_control = priv->bad_flow_control;
302 spin_unlock_irqrestore(&priv->lock, flags);
303
304 old_iflag = old_termios->c_iflag;
305 old_cflag = old_termios->c_cflag;
306
307 /* Set the baud rate */
308 if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
309 /* reassert DTR and (maybe) RTS on transition from B0 */
310 if ((old_cflag & CBAUD) == B0) {
311 control_state |= (TIOCM_DTR|TIOCM_RTS);
312 if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 1) < 0)
313 dev_err(&port->dev, "Set DTR error\n");
314 /* don't set RTS if using hardware flow control */
315 if (!(old_cflag & CRTSCTS))
316 if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST
317 , 1) < 0)
318 dev_err(&port->dev, "Set RTS error\n");
319 }
320 }
321
322 baud = tty_get_baud_rate(tty);
323 if (baud) {
324 urb_value = BELKIN_SA_BAUD(baud);
325 /* Clip to maximum speed */
326 if (urb_value == 0)
327 urb_value = 1;
328 /* Turn it back into a resulting real baud rate */
329 baud = BELKIN_SA_BAUD(urb_value);
330
331 /* Report the actual baud rate back to the caller */
332 tty_encode_baud_rate(tty, baud, baud);
333 if (BSA_USB_CMD(BELKIN_SA_SET_BAUDRATE_REQUEST, urb_value) < 0)
334 dev_err(&port->dev, "Set baudrate error\n");
335 } else {
336 /* Disable flow control */
337 if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST,
338 BELKIN_SA_FLOW_NONE) < 0)
339 dev_err(&port->dev, "Disable flowcontrol error\n");
340 /* Drop RTS and DTR */
341 control_state &= ~(TIOCM_DTR | TIOCM_RTS);
342 if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 0) < 0)
343 dev_err(&port->dev, "DTR LOW error\n");
344 if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, 0) < 0)
345 dev_err(&port->dev, "RTS LOW error\n");
346 }
347
348 /* set the parity */
349 if ((cflag ^ old_cflag) & (PARENB | PARODD)) {
350 if (cflag & PARENB)
351 urb_value = (cflag & PARODD) ? BELKIN_SA_PARITY_ODD
352 : BELKIN_SA_PARITY_EVEN;
353 else
354 urb_value = BELKIN_SA_PARITY_NONE;
355 if (BSA_USB_CMD(BELKIN_SA_SET_PARITY_REQUEST, urb_value) < 0)
356 dev_err(&port->dev, "Set parity error\n");
357 }
358
359 /* set the number of data bits */
360 if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
361 urb_value = BELKIN_SA_DATA_BITS(tty_get_char_size(cflag));
362 if (BSA_USB_CMD(BELKIN_SA_SET_DATA_BITS_REQUEST, urb_value) < 0)
363 dev_err(&port->dev, "Set data bits error\n");
364 }
365
366 /* set the number of stop bits */
367 if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
368 urb_value = (cflag & CSTOPB) ? BELKIN_SA_STOP_BITS(2)
369 : BELKIN_SA_STOP_BITS(1);
370 if (BSA_USB_CMD(BELKIN_SA_SET_STOP_BITS_REQUEST,
371 urb_value) < 0)
372 dev_err(&port->dev, "Set stop bits error\n");
373 }
374
375 /* Set flow control */
376 if (((iflag ^ old_iflag) & (IXOFF | IXON)) ||
377 ((cflag ^ old_cflag) & CRTSCTS)) {
378 urb_value = 0;
379 if ((iflag & IXOFF) || (iflag & IXON))
380 urb_value |= (BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
381 else
382 urb_value &= ~(BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
383
384 if (cflag & CRTSCTS)
385 urb_value |= (BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
386 else
387 urb_value &= ~(BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
388
389 if (bad_flow_control)
390 urb_value &= ~(BELKIN_SA_FLOW_IRTS);
391
392 if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST, urb_value) < 0)
393 dev_err(&port->dev, "Set flow control error\n");
394 }
395
396 /* save off the modified port settings */
397 spin_lock_irqsave(&priv->lock, flags);
398 priv->control_state = control_state;
399 spin_unlock_irqrestore(&priv->lock, flags);
400 }
401
belkin_sa_break_ctl(struct tty_struct * tty,int break_state)402 static int belkin_sa_break_ctl(struct tty_struct *tty, int break_state)
403 {
404 struct usb_serial_port *port = tty->driver_data;
405 struct usb_serial *serial = port->serial;
406 int ret;
407
408 ret = BSA_USB_CMD(BELKIN_SA_SET_BREAK_REQUEST, break_state ? 1 : 0);
409 if (ret < 0) {
410 dev_err(&port->dev, "Set break_ctl %d\n", break_state);
411 return ret;
412 }
413
414 return 0;
415 }
416
belkin_sa_tiocmget(struct tty_struct * tty)417 static int belkin_sa_tiocmget(struct tty_struct *tty)
418 {
419 struct usb_serial_port *port = tty->driver_data;
420 struct belkin_sa_private *priv = usb_get_serial_port_data(port);
421 unsigned long control_state;
422 unsigned long flags;
423
424 spin_lock_irqsave(&priv->lock, flags);
425 control_state = priv->control_state;
426 spin_unlock_irqrestore(&priv->lock, flags);
427
428 return control_state;
429 }
430
belkin_sa_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)431 static int belkin_sa_tiocmset(struct tty_struct *tty,
432 unsigned int set, unsigned int clear)
433 {
434 struct usb_serial_port *port = tty->driver_data;
435 struct usb_serial *serial = port->serial;
436 struct belkin_sa_private *priv = usb_get_serial_port_data(port);
437 unsigned long control_state;
438 unsigned long flags;
439 int retval;
440 int rts = 0;
441 int dtr = 0;
442
443 spin_lock_irqsave(&priv->lock, flags);
444 control_state = priv->control_state;
445
446 if (set & TIOCM_RTS) {
447 control_state |= TIOCM_RTS;
448 rts = 1;
449 }
450 if (set & TIOCM_DTR) {
451 control_state |= TIOCM_DTR;
452 dtr = 1;
453 }
454 if (clear & TIOCM_RTS) {
455 control_state &= ~TIOCM_RTS;
456 rts = 0;
457 }
458 if (clear & TIOCM_DTR) {
459 control_state &= ~TIOCM_DTR;
460 dtr = 0;
461 }
462
463 priv->control_state = control_state;
464 spin_unlock_irqrestore(&priv->lock, flags);
465
466 retval = BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, rts);
467 if (retval < 0) {
468 dev_err(&port->dev, "Set RTS error %d\n", retval);
469 goto exit;
470 }
471
472 retval = BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, dtr);
473 if (retval < 0) {
474 dev_err(&port->dev, "Set DTR error %d\n", retval);
475 goto exit;
476 }
477 exit:
478 return retval;
479 }
480
481 module_usb_serial_driver(serial_drivers, id_table);
482
483 MODULE_AUTHOR(DRIVER_AUTHOR);
484 MODULE_DESCRIPTION(DRIVER_DESC);
485 MODULE_LICENSE("GPL");
486