xref: /openbmc/linux/drivers/usb/serial/belkin_sa.c (revision 95e9fd10)
1 /*
2  * Belkin USB Serial Adapter Driver
3  *
4  *  Copyright (C) 2000		William Greathouse (wgreathouse@smva.com)
5  *  Copyright (C) 2000-2001	Greg Kroah-Hartman (greg@kroah.com)
6  *  Copyright (C) 2010		Johan Hovold (jhovold@gmail.com)
7  *
8  *  This program is largely derived from work by the linux-usb group
9  *  and associated source files.  Please see the usb/serial files for
10  *  individual credits and copyrights.
11  *
12  *	This program is free software; you can redistribute it and/or modify
13  *	it under the terms of the GNU General Public License as published by
14  *	the Free Software Foundation; either version 2 of the License, or
15  *	(at your option) any later version.
16  *
17  * See Documentation/usb/usb-serial.txt for more information on using this
18  * driver
19  *
20  * TODO:
21  * -- Add true modem contol line query capability.  Currently we track the
22  *    states reported by the interrupt and the states we request.
23  * -- Add support for flush commands
24  */
25 
26 #include <linux/kernel.h>
27 #include <linux/errno.h>
28 #include <linux/init.h>
29 #include <linux/slab.h>
30 #include <linux/tty.h>
31 #include <linux/tty_driver.h>
32 #include <linux/tty_flip.h>
33 #include <linux/module.h>
34 #include <linux/spinlock.h>
35 #include <linux/uaccess.h>
36 #include <linux/usb.h>
37 #include <linux/usb/serial.h>
38 #include "belkin_sa.h"
39 
40 static bool debug;
41 
42 /*
43  * Version Information
44  */
45 #define DRIVER_VERSION "v1.3"
46 #define DRIVER_AUTHOR "William Greathouse <wgreathouse@smva.com>"
47 #define DRIVER_DESC "USB Belkin Serial converter driver"
48 
49 /* function prototypes for a Belkin USB Serial Adapter F5U103 */
50 static int  belkin_sa_startup(struct usb_serial *serial);
51 static void belkin_sa_release(struct usb_serial *serial);
52 static int  belkin_sa_open(struct tty_struct *tty,
53 			struct usb_serial_port *port);
54 static void belkin_sa_close(struct usb_serial_port *port);
55 static void belkin_sa_read_int_callback(struct urb *urb);
56 static void belkin_sa_process_read_urb(struct urb *urb);
57 static void belkin_sa_set_termios(struct tty_struct *tty,
58 			struct usb_serial_port *port, struct ktermios * old);
59 static void belkin_sa_break_ctl(struct tty_struct *tty, int break_state);
60 static int  belkin_sa_tiocmget(struct tty_struct *tty);
61 static int  belkin_sa_tiocmset(struct tty_struct *tty,
62 					unsigned int set, unsigned int clear);
63 
64 
65 static const struct usb_device_id id_table[] = {
66 	{ USB_DEVICE(BELKIN_SA_VID, BELKIN_SA_PID) },
67 	{ USB_DEVICE(BELKIN_OLD_VID, BELKIN_OLD_PID) },
68 	{ USB_DEVICE(PERACOM_VID, PERACOM_PID) },
69 	{ USB_DEVICE(GOHUBS_VID, GOHUBS_PID) },
70 	{ USB_DEVICE(GOHUBS_VID, HANDYLINK_PID) },
71 	{ USB_DEVICE(BELKIN_DOCKSTATION_VID, BELKIN_DOCKSTATION_PID) },
72 	{ }	/* Terminating entry */
73 };
74 MODULE_DEVICE_TABLE(usb, id_table);
75 
76 /* All of the device info needed for the serial converters */
77 static struct usb_serial_driver belkin_device = {
78 	.driver = {
79 		.owner =	THIS_MODULE,
80 		.name =		"belkin",
81 	},
82 	.description =		"Belkin / Peracom / GoHubs USB Serial Adapter",
83 	.id_table =		id_table,
84 	.num_ports =		1,
85 	.open =			belkin_sa_open,
86 	.close =		belkin_sa_close,
87 	.read_int_callback =	belkin_sa_read_int_callback,
88 	.process_read_urb =	belkin_sa_process_read_urb,
89 	.set_termios =		belkin_sa_set_termios,
90 	.break_ctl =		belkin_sa_break_ctl,
91 	.tiocmget =		belkin_sa_tiocmget,
92 	.tiocmset =		belkin_sa_tiocmset,
93 	.attach =		belkin_sa_startup,
94 	.release =		belkin_sa_release,
95 };
96 
97 static struct usb_serial_driver * const serial_drivers[] = {
98 	&belkin_device, NULL
99 };
100 
101 struct belkin_sa_private {
102 	spinlock_t		lock;
103 	unsigned long		control_state;
104 	unsigned char		last_lsr;
105 	unsigned char		last_msr;
106 	int			bad_flow_control;
107 };
108 
109 
110 /*
111  * ***************************************************************************
112  * Belkin USB Serial Adapter F5U103 specific driver functions
113  * ***************************************************************************
114  */
115 
116 #define WDR_TIMEOUT 5000 /* default urb timeout */
117 
118 /* assumes that struct usb_serial *serial is available */
119 #define BSA_USB_CMD(c, v) usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), \
120 					    (c), BELKIN_SA_SET_REQUEST_TYPE, \
121 					    (v), 0, NULL, 0, WDR_TIMEOUT)
122 
123 /* do some startup allocations not currently performed by usb_serial_probe() */
124 static int belkin_sa_startup(struct usb_serial *serial)
125 {
126 	struct usb_device *dev = serial->dev;
127 	struct belkin_sa_private *priv;
128 
129 	/* allocate the private data structure */
130 	priv = kmalloc(sizeof(struct belkin_sa_private), GFP_KERNEL);
131 	if (!priv)
132 		return -1; /* error */
133 	/* set initial values for control structures */
134 	spin_lock_init(&priv->lock);
135 	priv->control_state = 0;
136 	priv->last_lsr = 0;
137 	priv->last_msr = 0;
138 	/* see comments at top of file */
139 	priv->bad_flow_control =
140 		(le16_to_cpu(dev->descriptor.bcdDevice) <= 0x0206) ? 1 : 0;
141 	dev_info(&dev->dev, "bcdDevice: %04x, bfc: %d\n",
142 					le16_to_cpu(dev->descriptor.bcdDevice),
143 					priv->bad_flow_control);
144 
145 	init_waitqueue_head(&serial->port[0]->write_wait);
146 	usb_set_serial_port_data(serial->port[0], priv);
147 
148 	return 0;
149 }
150 
151 static void belkin_sa_release(struct usb_serial *serial)
152 {
153 	int i;
154 
155 	for (i = 0; i < serial->num_ports; ++i)
156 		kfree(usb_get_serial_port_data(serial->port[i]));
157 }
158 
159 static int belkin_sa_open(struct tty_struct *tty,
160 					struct usb_serial_port *port)
161 {
162 	int retval;
163 
164 	retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
165 	if (retval) {
166 		dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
167 		return retval;
168 	}
169 
170 	retval = usb_serial_generic_open(tty, port);
171 	if (retval)
172 		usb_kill_urb(port->interrupt_in_urb);
173 
174 	return retval;
175 }
176 
177 static void belkin_sa_close(struct usb_serial_port *port)
178 {
179 	usb_serial_generic_close(port);
180 	usb_kill_urb(port->interrupt_in_urb);
181 }
182 
183 static void belkin_sa_read_int_callback(struct urb *urb)
184 {
185 	struct usb_serial_port *port = urb->context;
186 	struct belkin_sa_private *priv;
187 	unsigned char *data = urb->transfer_buffer;
188 	int retval;
189 	int status = urb->status;
190 	unsigned long flags;
191 
192 	switch (status) {
193 	case 0:
194 		/* success */
195 		break;
196 	case -ECONNRESET:
197 	case -ENOENT:
198 	case -ESHUTDOWN:
199 		/* this urb is terminated, clean up */
200 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
201 			__func__, status);
202 		return;
203 	default:
204 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
205 			__func__, status);
206 		goto exit;
207 	}
208 
209 	usb_serial_debug_data(debug, &port->dev, __func__,
210 					urb->actual_length, data);
211 
212 	/* Handle known interrupt data */
213 	/* ignore data[0] and data[1] */
214 
215 	priv = usb_get_serial_port_data(port);
216 	spin_lock_irqsave(&priv->lock, flags);
217 	priv->last_msr = data[BELKIN_SA_MSR_INDEX];
218 
219 	/* Record Control Line states */
220 	if (priv->last_msr & BELKIN_SA_MSR_DSR)
221 		priv->control_state |= TIOCM_DSR;
222 	else
223 		priv->control_state &= ~TIOCM_DSR;
224 
225 	if (priv->last_msr & BELKIN_SA_MSR_CTS)
226 		priv->control_state |= TIOCM_CTS;
227 	else
228 		priv->control_state &= ~TIOCM_CTS;
229 
230 	if (priv->last_msr & BELKIN_SA_MSR_RI)
231 		priv->control_state |= TIOCM_RI;
232 	else
233 		priv->control_state &= ~TIOCM_RI;
234 
235 	if (priv->last_msr & BELKIN_SA_MSR_CD)
236 		priv->control_state |= TIOCM_CD;
237 	else
238 		priv->control_state &= ~TIOCM_CD;
239 
240 	priv->last_lsr = data[BELKIN_SA_LSR_INDEX];
241 	spin_unlock_irqrestore(&priv->lock, flags);
242 exit:
243 	retval = usb_submit_urb(urb, GFP_ATOMIC);
244 	if (retval)
245 		dev_err(&port->dev, "%s - usb_submit_urb failed with "
246 			"result %d\n", __func__, retval);
247 }
248 
249 static void belkin_sa_process_read_urb(struct urb *urb)
250 {
251 	struct usb_serial_port *port = urb->context;
252 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
253 	struct tty_struct *tty;
254 	unsigned char *data = urb->transfer_buffer;
255 	unsigned long flags;
256 	unsigned char status;
257 	char tty_flag;
258 
259 	/* Update line status */
260 	tty_flag = TTY_NORMAL;
261 
262 	spin_lock_irqsave(&priv->lock, flags);
263 	status = priv->last_lsr;
264 	priv->last_lsr &= ~BELKIN_SA_LSR_ERR;
265 	spin_unlock_irqrestore(&priv->lock, flags);
266 
267 	if (!urb->actual_length)
268 		return;
269 
270 	tty = tty_port_tty_get(&port->port);
271 	if (!tty)
272 		return;
273 
274 	if (status & BELKIN_SA_LSR_ERR) {
275 		/* Break takes precedence over parity, which takes precedence
276 		 * over framing errors. */
277 		if (status & BELKIN_SA_LSR_BI)
278 			tty_flag = TTY_BREAK;
279 		else if (status & BELKIN_SA_LSR_PE)
280 			tty_flag = TTY_PARITY;
281 		else if (status & BELKIN_SA_LSR_FE)
282 			tty_flag = TTY_FRAME;
283 		dev_dbg(&port->dev, "tty_flag = %d\n", tty_flag);
284 
285 		/* Overrun is special, not associated with a char. */
286 		if (status & BELKIN_SA_LSR_OE)
287 			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
288 	}
289 
290 	tty_insert_flip_string_fixed_flag(tty, data, tty_flag,
291 							urb->actual_length);
292 	tty_flip_buffer_push(tty);
293 	tty_kref_put(tty);
294 }
295 
296 static void belkin_sa_set_termios(struct tty_struct *tty,
297 		struct usb_serial_port *port, struct ktermios *old_termios)
298 {
299 	struct usb_serial *serial = port->serial;
300 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
301 	unsigned int iflag;
302 	unsigned int cflag;
303 	unsigned int old_iflag = 0;
304 	unsigned int old_cflag = 0;
305 	__u16 urb_value = 0; /* Will hold the new flags */
306 	unsigned long flags;
307 	unsigned long control_state;
308 	int bad_flow_control;
309 	speed_t baud;
310 	struct ktermios *termios = tty->termios;
311 
312 	iflag = termios->c_iflag;
313 	cflag = termios->c_cflag;
314 
315 	termios->c_cflag &= ~CMSPAR;
316 
317 	/* get a local copy of the current port settings */
318 	spin_lock_irqsave(&priv->lock, flags);
319 	control_state = priv->control_state;
320 	bad_flow_control = priv->bad_flow_control;
321 	spin_unlock_irqrestore(&priv->lock, flags);
322 
323 	old_iflag = old_termios->c_iflag;
324 	old_cflag = old_termios->c_cflag;
325 
326 	/* Set the baud rate */
327 	if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
328 		/* reassert DTR and (maybe) RTS on transition from B0 */
329 		if ((old_cflag & CBAUD) == B0) {
330 			control_state |= (TIOCM_DTR|TIOCM_RTS);
331 			if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 1) < 0)
332 				dev_err(&port->dev, "Set DTR error\n");
333 			/* don't set RTS if using hardware flow control */
334 			if (!(old_cflag & CRTSCTS))
335 				if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST
336 								, 1) < 0)
337 					dev_err(&port->dev, "Set RTS error\n");
338 		}
339 	}
340 
341 	baud = tty_get_baud_rate(tty);
342 	if (baud) {
343 		urb_value = BELKIN_SA_BAUD(baud);
344 		/* Clip to maximum speed */
345 		if (urb_value == 0)
346 			urb_value = 1;
347 		/* Turn it back into a resulting real baud rate */
348 		baud = BELKIN_SA_BAUD(urb_value);
349 
350 		/* Report the actual baud rate back to the caller */
351 		tty_encode_baud_rate(tty, baud, baud);
352 		if (BSA_USB_CMD(BELKIN_SA_SET_BAUDRATE_REQUEST, urb_value) < 0)
353 			dev_err(&port->dev, "Set baudrate error\n");
354 	} else {
355 		/* Disable flow control */
356 		if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST,
357 						BELKIN_SA_FLOW_NONE) < 0)
358 			dev_err(&port->dev, "Disable flowcontrol error\n");
359 		/* Drop RTS and DTR */
360 		control_state &= ~(TIOCM_DTR | TIOCM_RTS);
361 		if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 0) < 0)
362 			dev_err(&port->dev, "DTR LOW error\n");
363 		if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, 0) < 0)
364 			dev_err(&port->dev, "RTS LOW error\n");
365 	}
366 
367 	/* set the parity */
368 	if ((cflag ^ old_cflag) & (PARENB | PARODD)) {
369 		if (cflag & PARENB)
370 			urb_value = (cflag & PARODD) ?  BELKIN_SA_PARITY_ODD
371 						: BELKIN_SA_PARITY_EVEN;
372 		else
373 			urb_value = BELKIN_SA_PARITY_NONE;
374 		if (BSA_USB_CMD(BELKIN_SA_SET_PARITY_REQUEST, urb_value) < 0)
375 			dev_err(&port->dev, "Set parity error\n");
376 	}
377 
378 	/* set the number of data bits */
379 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
380 		switch (cflag & CSIZE) {
381 		case CS5:
382 			urb_value = BELKIN_SA_DATA_BITS(5);
383 			break;
384 		case CS6:
385 			urb_value = BELKIN_SA_DATA_BITS(6);
386 			break;
387 		case CS7:
388 			urb_value = BELKIN_SA_DATA_BITS(7);
389 			break;
390 		case CS8:
391 			urb_value = BELKIN_SA_DATA_BITS(8);
392 			break;
393 		default:
394 			dev_dbg(&port->dev,
395 				"CSIZE was not CS5-CS8, using default of 8\n");
396 			urb_value = BELKIN_SA_DATA_BITS(8);
397 			break;
398 		}
399 		if (BSA_USB_CMD(BELKIN_SA_SET_DATA_BITS_REQUEST, urb_value) < 0)
400 			dev_err(&port->dev, "Set data bits error\n");
401 	}
402 
403 	/* set the number of stop bits */
404 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
405 		urb_value = (cflag & CSTOPB) ? BELKIN_SA_STOP_BITS(2)
406 						: BELKIN_SA_STOP_BITS(1);
407 		if (BSA_USB_CMD(BELKIN_SA_SET_STOP_BITS_REQUEST,
408 							urb_value) < 0)
409 			dev_err(&port->dev, "Set stop bits error\n");
410 	}
411 
412 	/* Set flow control */
413 	if (((iflag ^ old_iflag) & (IXOFF | IXON)) ||
414 		((cflag ^ old_cflag) & CRTSCTS)) {
415 		urb_value = 0;
416 		if ((iflag & IXOFF) || (iflag & IXON))
417 			urb_value |= (BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
418 		else
419 			urb_value &= ~(BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
420 
421 		if (cflag & CRTSCTS)
422 			urb_value |=  (BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
423 		else
424 			urb_value &= ~(BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
425 
426 		if (bad_flow_control)
427 			urb_value &= ~(BELKIN_SA_FLOW_IRTS);
428 
429 		if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST, urb_value) < 0)
430 			dev_err(&port->dev, "Set flow control error\n");
431 	}
432 
433 	/* save off the modified port settings */
434 	spin_lock_irqsave(&priv->lock, flags);
435 	priv->control_state = control_state;
436 	spin_unlock_irqrestore(&priv->lock, flags);
437 }
438 
439 static void belkin_sa_break_ctl(struct tty_struct *tty, int break_state)
440 {
441 	struct usb_serial_port *port = tty->driver_data;
442 	struct usb_serial *serial = port->serial;
443 
444 	if (BSA_USB_CMD(BELKIN_SA_SET_BREAK_REQUEST, break_state ? 1 : 0) < 0)
445 		dev_err(&port->dev, "Set break_ctl %d\n", break_state);
446 }
447 
448 static int belkin_sa_tiocmget(struct tty_struct *tty)
449 {
450 	struct usb_serial_port *port = tty->driver_data;
451 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
452 	unsigned long control_state;
453 	unsigned long flags;
454 
455 	spin_lock_irqsave(&priv->lock, flags);
456 	control_state = priv->control_state;
457 	spin_unlock_irqrestore(&priv->lock, flags);
458 
459 	return control_state;
460 }
461 
462 static int belkin_sa_tiocmset(struct tty_struct *tty,
463 			       unsigned int set, unsigned int clear)
464 {
465 	struct usb_serial_port *port = tty->driver_data;
466 	struct usb_serial *serial = port->serial;
467 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
468 	unsigned long control_state;
469 	unsigned long flags;
470 	int retval;
471 	int rts = 0;
472 	int dtr = 0;
473 
474 	spin_lock_irqsave(&priv->lock, flags);
475 	control_state = priv->control_state;
476 
477 	if (set & TIOCM_RTS) {
478 		control_state |= TIOCM_RTS;
479 		rts = 1;
480 	}
481 	if (set & TIOCM_DTR) {
482 		control_state |= TIOCM_DTR;
483 		dtr = 1;
484 	}
485 	if (clear & TIOCM_RTS) {
486 		control_state &= ~TIOCM_RTS;
487 		rts = 0;
488 	}
489 	if (clear & TIOCM_DTR) {
490 		control_state &= ~TIOCM_DTR;
491 		dtr = 0;
492 	}
493 
494 	priv->control_state = control_state;
495 	spin_unlock_irqrestore(&priv->lock, flags);
496 
497 	retval = BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, rts);
498 	if (retval < 0) {
499 		dev_err(&port->dev, "Set RTS error %d\n", retval);
500 		goto exit;
501 	}
502 
503 	retval = BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, dtr);
504 	if (retval < 0) {
505 		dev_err(&port->dev, "Set DTR error %d\n", retval);
506 		goto exit;
507 	}
508 exit:
509 	return retval;
510 }
511 
512 module_usb_serial_driver(serial_drivers, id_table);
513 
514 MODULE_AUTHOR(DRIVER_AUTHOR);
515 MODULE_DESCRIPTION(DRIVER_DESC);
516 MODULE_VERSION(DRIVER_VERSION);
517 MODULE_LICENSE("GPL");
518 
519 module_param(debug, bool, S_IRUGO | S_IWUSR);
520 MODULE_PARM_DESC(debug, "Debug enabled or not");
521