xref: /openbmc/linux/drivers/usb/serial/belkin_sa.c (revision 0da85d1e)
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 control 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/slab.h>
29 #include <linux/tty.h>
30 #include <linux/tty_driver.h>
31 #include <linux/tty_flip.h>
32 #include <linux/module.h>
33 #include <linux/spinlock.h>
34 #include <linux/uaccess.h>
35 #include <linux/usb.h>
36 #include <linux/usb/serial.h>
37 #include "belkin_sa.h"
38 
39 #define DRIVER_AUTHOR "William Greathouse <wgreathouse@smva.com>"
40 #define DRIVER_DESC "USB Belkin Serial converter driver"
41 
42 /* function prototypes for a Belkin USB Serial Adapter F5U103 */
43 static int belkin_sa_port_probe(struct usb_serial_port *port);
44 static int belkin_sa_port_remove(struct usb_serial_port *port);
45 static int  belkin_sa_open(struct tty_struct *tty,
46 			struct usb_serial_port *port);
47 static void belkin_sa_close(struct usb_serial_port *port);
48 static void belkin_sa_read_int_callback(struct urb *urb);
49 static void belkin_sa_process_read_urb(struct urb *urb);
50 static void belkin_sa_set_termios(struct tty_struct *tty,
51 			struct usb_serial_port *port, struct ktermios * old);
52 static void belkin_sa_break_ctl(struct tty_struct *tty, int break_state);
53 static int  belkin_sa_tiocmget(struct tty_struct *tty);
54 static int  belkin_sa_tiocmset(struct tty_struct *tty,
55 					unsigned int set, unsigned int clear);
56 
57 
58 static const struct usb_device_id id_table[] = {
59 	{ USB_DEVICE(BELKIN_SA_VID, BELKIN_SA_PID) },
60 	{ USB_DEVICE(BELKIN_OLD_VID, BELKIN_OLD_PID) },
61 	{ USB_DEVICE(PERACOM_VID, PERACOM_PID) },
62 	{ USB_DEVICE(GOHUBS_VID, GOHUBS_PID) },
63 	{ USB_DEVICE(GOHUBS_VID, HANDYLINK_PID) },
64 	{ USB_DEVICE(BELKIN_DOCKSTATION_VID, BELKIN_DOCKSTATION_PID) },
65 	{ }	/* Terminating entry */
66 };
67 MODULE_DEVICE_TABLE(usb, id_table);
68 
69 /* All of the device info needed for the serial converters */
70 static struct usb_serial_driver belkin_device = {
71 	.driver = {
72 		.owner =	THIS_MODULE,
73 		.name =		"belkin",
74 	},
75 	.description =		"Belkin / Peracom / GoHubs USB Serial Adapter",
76 	.id_table =		id_table,
77 	.num_ports =		1,
78 	.open =			belkin_sa_open,
79 	.close =		belkin_sa_close,
80 	.read_int_callback =	belkin_sa_read_int_callback,
81 	.process_read_urb =	belkin_sa_process_read_urb,
82 	.set_termios =		belkin_sa_set_termios,
83 	.break_ctl =		belkin_sa_break_ctl,
84 	.tiocmget =		belkin_sa_tiocmget,
85 	.tiocmset =		belkin_sa_tiocmset,
86 	.port_probe =		belkin_sa_port_probe,
87 	.port_remove =		belkin_sa_port_remove,
88 };
89 
90 static struct usb_serial_driver * const serial_drivers[] = {
91 	&belkin_device, NULL
92 };
93 
94 struct belkin_sa_private {
95 	spinlock_t		lock;
96 	unsigned long		control_state;
97 	unsigned char		last_lsr;
98 	unsigned char		last_msr;
99 	int			bad_flow_control;
100 };
101 
102 
103 /*
104  * ***************************************************************************
105  * Belkin USB Serial Adapter F5U103 specific driver functions
106  * ***************************************************************************
107  */
108 
109 #define WDR_TIMEOUT 5000 /* default urb timeout */
110 
111 /* assumes that struct usb_serial *serial is available */
112 #define BSA_USB_CMD(c, v) usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), \
113 					    (c), BELKIN_SA_SET_REQUEST_TYPE, \
114 					    (v), 0, NULL, 0, WDR_TIMEOUT)
115 
116 static int belkin_sa_port_probe(struct usb_serial_port *port)
117 {
118 	struct usb_device *dev = port->serial->dev;
119 	struct belkin_sa_private *priv;
120 
121 	priv = kmalloc(sizeof(struct belkin_sa_private), GFP_KERNEL);
122 	if (!priv)
123 		return -ENOMEM;
124 
125 	spin_lock_init(&priv->lock);
126 	priv->control_state = 0;
127 	priv->last_lsr = 0;
128 	priv->last_msr = 0;
129 	/* see comments at top of file */
130 	priv->bad_flow_control =
131 		(le16_to_cpu(dev->descriptor.bcdDevice) <= 0x0206) ? 1 : 0;
132 	dev_info(&dev->dev, "bcdDevice: %04x, bfc: %d\n",
133 					le16_to_cpu(dev->descriptor.bcdDevice),
134 					priv->bad_flow_control);
135 
136 	usb_set_serial_port_data(port, priv);
137 
138 	return 0;
139 }
140 
141 static int belkin_sa_port_remove(struct usb_serial_port *port)
142 {
143 	struct belkin_sa_private *priv;
144 
145 	priv = usb_get_serial_port_data(port);
146 	kfree(priv);
147 
148 	return 0;
149 }
150 
151 static int belkin_sa_open(struct tty_struct *tty,
152 					struct usb_serial_port *port)
153 {
154 	int retval;
155 
156 	retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
157 	if (retval) {
158 		dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
159 		return retval;
160 	}
161 
162 	retval = usb_serial_generic_open(tty, port);
163 	if (retval)
164 		usb_kill_urb(port->interrupt_in_urb);
165 
166 	return retval;
167 }
168 
169 static void belkin_sa_close(struct usb_serial_port *port)
170 {
171 	usb_serial_generic_close(port);
172 	usb_kill_urb(port->interrupt_in_urb);
173 }
174 
175 static void belkin_sa_read_int_callback(struct urb *urb)
176 {
177 	struct usb_serial_port *port = urb->context;
178 	struct belkin_sa_private *priv;
179 	unsigned char *data = urb->transfer_buffer;
180 	int retval;
181 	int status = urb->status;
182 	unsigned long flags;
183 
184 	switch (status) {
185 	case 0:
186 		/* success */
187 		break;
188 	case -ECONNRESET:
189 	case -ENOENT:
190 	case -ESHUTDOWN:
191 		/* this urb is terminated, clean up */
192 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
193 			__func__, status);
194 		return;
195 	default:
196 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
197 			__func__, status);
198 		goto exit;
199 	}
200 
201 	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
202 
203 	/* Handle known interrupt data */
204 	/* ignore data[0] and data[1] */
205 
206 	priv = usb_get_serial_port_data(port);
207 	spin_lock_irqsave(&priv->lock, flags);
208 	priv->last_msr = data[BELKIN_SA_MSR_INDEX];
209 
210 	/* Record Control Line states */
211 	if (priv->last_msr & BELKIN_SA_MSR_DSR)
212 		priv->control_state |= TIOCM_DSR;
213 	else
214 		priv->control_state &= ~TIOCM_DSR;
215 
216 	if (priv->last_msr & BELKIN_SA_MSR_CTS)
217 		priv->control_state |= TIOCM_CTS;
218 	else
219 		priv->control_state &= ~TIOCM_CTS;
220 
221 	if (priv->last_msr & BELKIN_SA_MSR_RI)
222 		priv->control_state |= TIOCM_RI;
223 	else
224 		priv->control_state &= ~TIOCM_RI;
225 
226 	if (priv->last_msr & BELKIN_SA_MSR_CD)
227 		priv->control_state |= TIOCM_CD;
228 	else
229 		priv->control_state &= ~TIOCM_CD;
230 
231 	priv->last_lsr = data[BELKIN_SA_LSR_INDEX];
232 	spin_unlock_irqrestore(&priv->lock, flags);
233 exit:
234 	retval = usb_submit_urb(urb, GFP_ATOMIC);
235 	if (retval)
236 		dev_err(&port->dev, "%s - usb_submit_urb failed with "
237 			"result %d\n", __func__, retval);
238 }
239 
240 static void belkin_sa_process_read_urb(struct urb *urb)
241 {
242 	struct usb_serial_port *port = urb->context;
243 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
244 	unsigned char *data = urb->transfer_buffer;
245 	unsigned long flags;
246 	unsigned char status;
247 	char tty_flag;
248 
249 	/* Update line status */
250 	tty_flag = TTY_NORMAL;
251 
252 	spin_lock_irqsave(&priv->lock, flags);
253 	status = priv->last_lsr;
254 	priv->last_lsr &= ~BELKIN_SA_LSR_ERR;
255 	spin_unlock_irqrestore(&priv->lock, flags);
256 
257 	if (!urb->actual_length)
258 		return;
259 
260 	if (status & BELKIN_SA_LSR_ERR) {
261 		/* Break takes precedence over parity, which takes precedence
262 		 * over framing errors. */
263 		if (status & BELKIN_SA_LSR_BI)
264 			tty_flag = TTY_BREAK;
265 		else if (status & BELKIN_SA_LSR_PE)
266 			tty_flag = TTY_PARITY;
267 		else if (status & BELKIN_SA_LSR_FE)
268 			tty_flag = TTY_FRAME;
269 		dev_dbg(&port->dev, "tty_flag = %d\n", tty_flag);
270 
271 		/* Overrun is special, not associated with a char. */
272 		if (status & BELKIN_SA_LSR_OE)
273 			tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
274 	}
275 
276 	tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
277 							urb->actual_length);
278 	tty_flip_buffer_push(&port->port);
279 }
280 
281 static void belkin_sa_set_termios(struct tty_struct *tty,
282 		struct usb_serial_port *port, struct ktermios *old_termios)
283 {
284 	struct usb_serial *serial = port->serial;
285 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
286 	unsigned int iflag;
287 	unsigned int cflag;
288 	unsigned int old_iflag = 0;
289 	unsigned int old_cflag = 0;
290 	__u16 urb_value = 0; /* Will hold the new flags */
291 	unsigned long flags;
292 	unsigned long control_state;
293 	int bad_flow_control;
294 	speed_t baud;
295 	struct ktermios *termios = &tty->termios;
296 
297 	iflag = termios->c_iflag;
298 	cflag = termios->c_cflag;
299 
300 	termios->c_cflag &= ~CMSPAR;
301 
302 	/* get a local copy of the current port settings */
303 	spin_lock_irqsave(&priv->lock, flags);
304 	control_state = priv->control_state;
305 	bad_flow_control = priv->bad_flow_control;
306 	spin_unlock_irqrestore(&priv->lock, flags);
307 
308 	old_iflag = old_termios->c_iflag;
309 	old_cflag = old_termios->c_cflag;
310 
311 	/* Set the baud rate */
312 	if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
313 		/* reassert DTR and (maybe) RTS on transition from B0 */
314 		if ((old_cflag & CBAUD) == B0) {
315 			control_state |= (TIOCM_DTR|TIOCM_RTS);
316 			if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 1) < 0)
317 				dev_err(&port->dev, "Set DTR error\n");
318 			/* don't set RTS if using hardware flow control */
319 			if (!(old_cflag & CRTSCTS))
320 				if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST
321 								, 1) < 0)
322 					dev_err(&port->dev, "Set RTS error\n");
323 		}
324 	}
325 
326 	baud = tty_get_baud_rate(tty);
327 	if (baud) {
328 		urb_value = BELKIN_SA_BAUD(baud);
329 		/* Clip to maximum speed */
330 		if (urb_value == 0)
331 			urb_value = 1;
332 		/* Turn it back into a resulting real baud rate */
333 		baud = BELKIN_SA_BAUD(urb_value);
334 
335 		/* Report the actual baud rate back to the caller */
336 		tty_encode_baud_rate(tty, baud, baud);
337 		if (BSA_USB_CMD(BELKIN_SA_SET_BAUDRATE_REQUEST, urb_value) < 0)
338 			dev_err(&port->dev, "Set baudrate error\n");
339 	} else {
340 		/* Disable flow control */
341 		if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST,
342 						BELKIN_SA_FLOW_NONE) < 0)
343 			dev_err(&port->dev, "Disable flowcontrol error\n");
344 		/* Drop RTS and DTR */
345 		control_state &= ~(TIOCM_DTR | TIOCM_RTS);
346 		if (BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, 0) < 0)
347 			dev_err(&port->dev, "DTR LOW error\n");
348 		if (BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, 0) < 0)
349 			dev_err(&port->dev, "RTS LOW error\n");
350 	}
351 
352 	/* set the parity */
353 	if ((cflag ^ old_cflag) & (PARENB | PARODD)) {
354 		if (cflag & PARENB)
355 			urb_value = (cflag & PARODD) ?  BELKIN_SA_PARITY_ODD
356 						: BELKIN_SA_PARITY_EVEN;
357 		else
358 			urb_value = BELKIN_SA_PARITY_NONE;
359 		if (BSA_USB_CMD(BELKIN_SA_SET_PARITY_REQUEST, urb_value) < 0)
360 			dev_err(&port->dev, "Set parity error\n");
361 	}
362 
363 	/* set the number of data bits */
364 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
365 		switch (cflag & CSIZE) {
366 		case CS5:
367 			urb_value = BELKIN_SA_DATA_BITS(5);
368 			break;
369 		case CS6:
370 			urb_value = BELKIN_SA_DATA_BITS(6);
371 			break;
372 		case CS7:
373 			urb_value = BELKIN_SA_DATA_BITS(7);
374 			break;
375 		case CS8:
376 			urb_value = BELKIN_SA_DATA_BITS(8);
377 			break;
378 		default:
379 			dev_dbg(&port->dev,
380 				"CSIZE was not CS5-CS8, using default of 8\n");
381 			urb_value = BELKIN_SA_DATA_BITS(8);
382 			break;
383 		}
384 		if (BSA_USB_CMD(BELKIN_SA_SET_DATA_BITS_REQUEST, urb_value) < 0)
385 			dev_err(&port->dev, "Set data bits error\n");
386 	}
387 
388 	/* set the number of stop bits */
389 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
390 		urb_value = (cflag & CSTOPB) ? BELKIN_SA_STOP_BITS(2)
391 						: BELKIN_SA_STOP_BITS(1);
392 		if (BSA_USB_CMD(BELKIN_SA_SET_STOP_BITS_REQUEST,
393 							urb_value) < 0)
394 			dev_err(&port->dev, "Set stop bits error\n");
395 	}
396 
397 	/* Set flow control */
398 	if (((iflag ^ old_iflag) & (IXOFF | IXON)) ||
399 		((cflag ^ old_cflag) & CRTSCTS)) {
400 		urb_value = 0;
401 		if ((iflag & IXOFF) || (iflag & IXON))
402 			urb_value |= (BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
403 		else
404 			urb_value &= ~(BELKIN_SA_FLOW_OXON | BELKIN_SA_FLOW_IXON);
405 
406 		if (cflag & CRTSCTS)
407 			urb_value |=  (BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
408 		else
409 			urb_value &= ~(BELKIN_SA_FLOW_OCTS | BELKIN_SA_FLOW_IRTS);
410 
411 		if (bad_flow_control)
412 			urb_value &= ~(BELKIN_SA_FLOW_IRTS);
413 
414 		if (BSA_USB_CMD(BELKIN_SA_SET_FLOW_CTRL_REQUEST, urb_value) < 0)
415 			dev_err(&port->dev, "Set flow control error\n");
416 	}
417 
418 	/* save off the modified port settings */
419 	spin_lock_irqsave(&priv->lock, flags);
420 	priv->control_state = control_state;
421 	spin_unlock_irqrestore(&priv->lock, flags);
422 }
423 
424 static void belkin_sa_break_ctl(struct tty_struct *tty, int break_state)
425 {
426 	struct usb_serial_port *port = tty->driver_data;
427 	struct usb_serial *serial = port->serial;
428 
429 	if (BSA_USB_CMD(BELKIN_SA_SET_BREAK_REQUEST, break_state ? 1 : 0) < 0)
430 		dev_err(&port->dev, "Set break_ctl %d\n", break_state);
431 }
432 
433 static int belkin_sa_tiocmget(struct tty_struct *tty)
434 {
435 	struct usb_serial_port *port = tty->driver_data;
436 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
437 	unsigned long control_state;
438 	unsigned long flags;
439 
440 	spin_lock_irqsave(&priv->lock, flags);
441 	control_state = priv->control_state;
442 	spin_unlock_irqrestore(&priv->lock, flags);
443 
444 	return control_state;
445 }
446 
447 static int belkin_sa_tiocmset(struct tty_struct *tty,
448 			       unsigned int set, unsigned int clear)
449 {
450 	struct usb_serial_port *port = tty->driver_data;
451 	struct usb_serial *serial = port->serial;
452 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
453 	unsigned long control_state;
454 	unsigned long flags;
455 	int retval;
456 	int rts = 0;
457 	int dtr = 0;
458 
459 	spin_lock_irqsave(&priv->lock, flags);
460 	control_state = priv->control_state;
461 
462 	if (set & TIOCM_RTS) {
463 		control_state |= TIOCM_RTS;
464 		rts = 1;
465 	}
466 	if (set & TIOCM_DTR) {
467 		control_state |= TIOCM_DTR;
468 		dtr = 1;
469 	}
470 	if (clear & TIOCM_RTS) {
471 		control_state &= ~TIOCM_RTS;
472 		rts = 0;
473 	}
474 	if (clear & TIOCM_DTR) {
475 		control_state &= ~TIOCM_DTR;
476 		dtr = 0;
477 	}
478 
479 	priv->control_state = control_state;
480 	spin_unlock_irqrestore(&priv->lock, flags);
481 
482 	retval = BSA_USB_CMD(BELKIN_SA_SET_RTS_REQUEST, rts);
483 	if (retval < 0) {
484 		dev_err(&port->dev, "Set RTS error %d\n", retval);
485 		goto exit;
486 	}
487 
488 	retval = BSA_USB_CMD(BELKIN_SA_SET_DTR_REQUEST, dtr);
489 	if (retval < 0) {
490 		dev_err(&port->dev, "Set DTR error %d\n", retval);
491 		goto exit;
492 	}
493 exit:
494 	return retval;
495 }
496 
497 module_usb_serial_driver(serial_drivers, id_table);
498 
499 MODULE_AUTHOR(DRIVER_AUTHOR);
500 MODULE_DESCRIPTION(DRIVER_DESC);
501 MODULE_LICENSE("GPL");
502