xref: /openbmc/linux/drivers/usb/serial/ssu100.c (revision 97da55fc)
1 /*
2  * usb-serial driver for Quatech SSU-100
3  *
4  * based on ftdi_sio.c and the original serqt_usb.c from Quatech
5  *
6  */
7 
8 #include <linux/errno.h>
9 #include <linux/init.h>
10 #include <linux/slab.h>
11 #include <linux/tty.h>
12 #include <linux/tty_driver.h>
13 #include <linux/tty_flip.h>
14 #include <linux/module.h>
15 #include <linux/serial.h>
16 #include <linux/usb.h>
17 #include <linux/usb/serial.h>
18 #include <linux/serial_reg.h>
19 #include <linux/uaccess.h>
20 
21 #define QT_OPEN_CLOSE_CHANNEL       0xca
22 #define QT_SET_GET_DEVICE           0xc2
23 #define QT_SET_GET_REGISTER         0xc0
24 #define QT_GET_SET_PREBUF_TRIG_LVL  0xcc
25 #define QT_SET_ATF                  0xcd
26 #define QT_GET_SET_UART             0xc1
27 #define QT_TRANSFER_IN              0xc0
28 #define QT_HW_FLOW_CONTROL_MASK     0xc5
29 #define QT_SW_FLOW_CONTROL_MASK     0xc6
30 
31 #define  SERIAL_MSR_MASK            0xf0
32 
33 #define  SERIAL_CRTSCTS ((UART_MCR_RTS << 8) | UART_MSR_CTS)
34 
35 #define  SERIAL_EVEN_PARITY         (UART_LCR_PARITY | UART_LCR_EPAR)
36 
37 #define  MAX_BAUD_RATE              460800
38 
39 #define ATC_DISABLED                0x00
40 #define DUPMODE_BITS        0xc0
41 #define RR_BITS             0x03
42 #define LOOPMODE_BITS       0x41
43 #define RS232_MODE          0x00
44 #define RTSCTS_TO_CONNECTOR 0x40
45 #define CLKS_X4             0x02
46 #define FULLPWRBIT          0x00000080
47 #define NEXT_BOARD_POWER_BIT        0x00000004
48 
49 #define DRIVER_DESC "Quatech SSU-100 USB to Serial Driver"
50 
51 #define	USB_VENDOR_ID_QUATECH	0x061d	/* Quatech VID */
52 #define QUATECH_SSU100	0xC020	/* SSU100 */
53 
54 static const struct usb_device_id id_table[] = {
55 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU100)},
56 	{}			/* Terminating entry */
57 };
58 MODULE_DEVICE_TABLE(usb, id_table);
59 
60 struct ssu100_port_private {
61 	spinlock_t status_lock;
62 	u8 shadowLSR;
63 	u8 shadowMSR;
64 	wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
65 	struct async_icount icount;
66 };
67 
68 static inline int ssu100_control_msg(struct usb_device *dev,
69 				     u8 request, u16 data, u16 index)
70 {
71 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
72 			       request, 0x40, data, index,
73 			       NULL, 0, 300);
74 }
75 
76 static inline int ssu100_setdevice(struct usb_device *dev, u8 *data)
77 {
78 	u16 x = ((u16)(data[1] << 8) | (u16)(data[0]));
79 
80 	return ssu100_control_msg(dev, QT_SET_GET_DEVICE, x, 0);
81 }
82 
83 
84 static inline int ssu100_getdevice(struct usb_device *dev, u8 *data)
85 {
86 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
87 			       QT_SET_GET_DEVICE, 0xc0, 0, 0,
88 			       data, 3, 300);
89 }
90 
91 static inline int ssu100_getregister(struct usb_device *dev,
92 				     unsigned short uart,
93 				     unsigned short reg,
94 				     u8 *data)
95 {
96 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
97 			       QT_SET_GET_REGISTER, 0xc0, reg,
98 			       uart, data, sizeof(*data), 300);
99 
100 }
101 
102 
103 static inline int ssu100_setregister(struct usb_device *dev,
104 				     unsigned short uart,
105 				     unsigned short reg,
106 				     u16 data)
107 {
108 	u16 value = (data << 8) | reg;
109 
110 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
111 			       QT_SET_GET_REGISTER, 0x40, value, uart,
112 			       NULL, 0, 300);
113 
114 }
115 
116 #define set_mctrl(dev, set)		update_mctrl((dev), (set), 0)
117 #define clear_mctrl(dev, clear)	update_mctrl((dev), 0, (clear))
118 
119 /* these do not deal with device that have more than 1 port */
120 static inline int update_mctrl(struct usb_device *dev, unsigned int set,
121 			       unsigned int clear)
122 {
123 	unsigned urb_value;
124 	int result;
125 
126 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
127 		dev_dbg(&dev->dev, "%s - DTR|RTS not being set|cleared\n", __func__);
128 		return 0;	/* no change */
129 	}
130 
131 	clear &= ~set;	/* 'set' takes precedence over 'clear' */
132 	urb_value = 0;
133 	if (set & TIOCM_DTR)
134 		urb_value |= UART_MCR_DTR;
135 	if (set & TIOCM_RTS)
136 		urb_value |= UART_MCR_RTS;
137 
138 	result = ssu100_setregister(dev, 0, UART_MCR, urb_value);
139 	if (result < 0)
140 		dev_dbg(&dev->dev, "%s Error from MODEM_CTRL urb\n", __func__);
141 
142 	return result;
143 }
144 
145 static int ssu100_initdevice(struct usb_device *dev)
146 {
147 	u8 *data;
148 	int result = 0;
149 
150 	data = kzalloc(3, GFP_KERNEL);
151 	if (!data)
152 		return -ENOMEM;
153 
154 	result = ssu100_getdevice(dev, data);
155 	if (result < 0) {
156 		dev_dbg(&dev->dev, "%s - get_device failed %i\n", __func__, result);
157 		goto out;
158 	}
159 
160 	data[1] &= ~FULLPWRBIT;
161 
162 	result = ssu100_setdevice(dev, data);
163 	if (result < 0) {
164 		dev_dbg(&dev->dev, "%s - setdevice failed %i\n", __func__, result);
165 		goto out;
166 	}
167 
168 	result = ssu100_control_msg(dev, QT_GET_SET_PREBUF_TRIG_LVL, 128, 0);
169 	if (result < 0) {
170 		dev_dbg(&dev->dev, "%s - set prebuffer level failed %i\n", __func__, result);
171 		goto out;
172 	}
173 
174 	result = ssu100_control_msg(dev, QT_SET_ATF, ATC_DISABLED, 0);
175 	if (result < 0) {
176 		dev_dbg(&dev->dev, "%s - set ATFprebuffer level failed %i\n", __func__, result);
177 		goto out;
178 	}
179 
180 	result = ssu100_getdevice(dev, data);
181 	if (result < 0) {
182 		dev_dbg(&dev->dev, "%s - get_device failed %i\n", __func__, result);
183 		goto out;
184 	}
185 
186 	data[0] &= ~(RR_BITS | DUPMODE_BITS);
187 	data[0] |= CLKS_X4;
188 	data[1] &= ~(LOOPMODE_BITS);
189 	data[1] |= RS232_MODE;
190 
191 	result = ssu100_setdevice(dev, data);
192 	if (result < 0) {
193 		dev_dbg(&dev->dev, "%s - setdevice failed %i\n", __func__, result);
194 		goto out;
195 	}
196 
197 out:	kfree(data);
198 	return result;
199 
200 }
201 
202 
203 static void ssu100_set_termios(struct tty_struct *tty,
204 			       struct usb_serial_port *port,
205 			       struct ktermios *old_termios)
206 {
207 	struct usb_device *dev = port->serial->dev;
208 	struct ktermios *termios = &tty->termios;
209 	u16 baud, divisor, remainder;
210 	unsigned int cflag = termios->c_cflag;
211 	u16 urb_value = 0; /* will hold the new flags */
212 	int result;
213 
214 	if (cflag & PARENB) {
215 		if (cflag & PARODD)
216 			urb_value |= UART_LCR_PARITY;
217 		else
218 			urb_value |= SERIAL_EVEN_PARITY;
219 	}
220 
221 	switch (cflag & CSIZE) {
222 	case CS5:
223 		urb_value |= UART_LCR_WLEN5;
224 		break;
225 	case CS6:
226 		urb_value |= UART_LCR_WLEN6;
227 		break;
228 	case CS7:
229 		urb_value |= UART_LCR_WLEN7;
230 		break;
231 	default:
232 	case CS8:
233 		urb_value |= UART_LCR_WLEN8;
234 		break;
235 	}
236 
237 	baud = tty_get_baud_rate(tty);
238 	if (!baud)
239 		baud = 9600;
240 
241 	dev_dbg(&port->dev, "%s - got baud = %d\n", __func__, baud);
242 
243 
244 	divisor = MAX_BAUD_RATE / baud;
245 	remainder = MAX_BAUD_RATE % baud;
246 	if (((remainder * 2) >= baud) && (baud != 110))
247 		divisor++;
248 
249 	urb_value = urb_value << 8;
250 
251 	result = ssu100_control_msg(dev, QT_GET_SET_UART, divisor, urb_value);
252 	if (result < 0)
253 		dev_dbg(&port->dev, "%s - set uart failed\n", __func__);
254 
255 	if (cflag & CRTSCTS)
256 		result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
257 					    SERIAL_CRTSCTS, 0);
258 	else
259 		result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
260 					    0, 0);
261 	if (result < 0)
262 		dev_dbg(&port->dev, "%s - set HW flow control failed\n", __func__);
263 
264 	if (I_IXOFF(tty) || I_IXON(tty)) {
265 		u16 x = ((u16)(START_CHAR(tty) << 8) | (u16)(STOP_CHAR(tty)));
266 
267 		result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
268 					    x, 0);
269 	} else
270 		result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
271 					    0, 0);
272 
273 	if (result < 0)
274 		dev_dbg(&port->dev, "%s - set SW flow control failed\n", __func__);
275 
276 }
277 
278 
279 static int ssu100_open(struct tty_struct *tty, struct usb_serial_port *port)
280 {
281 	struct usb_device *dev = port->serial->dev;
282 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
283 	u8 *data;
284 	int result;
285 	unsigned long flags;
286 
287 	data = kzalloc(2, GFP_KERNEL);
288 	if (!data)
289 		return -ENOMEM;
290 
291 	result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
292 				 QT_OPEN_CLOSE_CHANNEL,
293 				 QT_TRANSFER_IN, 0x01,
294 				 0, data, 2, 300);
295 	if (result < 0) {
296 		dev_dbg(&port->dev, "%s - open failed %i\n", __func__, result);
297 		kfree(data);
298 		return result;
299 	}
300 
301 	spin_lock_irqsave(&priv->status_lock, flags);
302 	priv->shadowLSR = data[0];
303 	priv->shadowMSR = data[1];
304 	spin_unlock_irqrestore(&priv->status_lock, flags);
305 
306 	kfree(data);
307 
308 /* set to 9600 */
309 	result = ssu100_control_msg(dev, QT_GET_SET_UART, 0x30, 0x0300);
310 	if (result < 0)
311 		dev_dbg(&port->dev, "%s - set uart failed\n", __func__);
312 
313 	if (tty)
314 		ssu100_set_termios(tty, port, &tty->termios);
315 
316 	return usb_serial_generic_open(tty, port);
317 }
318 
319 static void ssu100_close(struct usb_serial_port *port)
320 {
321 	usb_serial_generic_close(port);
322 }
323 
324 static int get_serial_info(struct usb_serial_port *port,
325 			   struct serial_struct __user *retinfo)
326 {
327 	struct serial_struct tmp;
328 
329 	if (!retinfo)
330 		return -EFAULT;
331 
332 	memset(&tmp, 0, sizeof(tmp));
333 	tmp.line		= port->serial->minor;
334 	tmp.port		= 0;
335 	tmp.irq			= 0;
336 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
337 	tmp.xmit_fifo_size	= port->bulk_out_size;
338 	tmp.baud_base		= 9600;
339 	tmp.close_delay		= 5*HZ;
340 	tmp.closing_wait	= 30*HZ;
341 
342 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
343 		return -EFAULT;
344 	return 0;
345 }
346 
347 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
348 {
349 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
350 	struct async_icount prev, cur;
351 	unsigned long flags;
352 
353 	spin_lock_irqsave(&priv->status_lock, flags);
354 	prev = priv->icount;
355 	spin_unlock_irqrestore(&priv->status_lock, flags);
356 
357 	while (1) {
358 		wait_event_interruptible(priv->delta_msr_wait,
359 					 ((priv->icount.rng != prev.rng) ||
360 					  (priv->icount.dsr != prev.dsr) ||
361 					  (priv->icount.dcd != prev.dcd) ||
362 					  (priv->icount.cts != prev.cts)));
363 
364 		if (signal_pending(current))
365 			return -ERESTARTSYS;
366 
367 		spin_lock_irqsave(&priv->status_lock, flags);
368 		cur = priv->icount;
369 		spin_unlock_irqrestore(&priv->status_lock, flags);
370 
371 		if ((prev.rng == cur.rng) &&
372 		    (prev.dsr == cur.dsr) &&
373 		    (prev.dcd == cur.dcd) &&
374 		    (prev.cts == cur.cts))
375 			return -EIO;
376 
377 		if ((arg & TIOCM_RNG && (prev.rng != cur.rng)) ||
378 		    (arg & TIOCM_DSR && (prev.dsr != cur.dsr)) ||
379 		    (arg & TIOCM_CD  && (prev.dcd != cur.dcd)) ||
380 		    (arg & TIOCM_CTS && (prev.cts != cur.cts)))
381 			return 0;
382 	}
383 	return 0;
384 }
385 
386 static int ssu100_get_icount(struct tty_struct *tty,
387 			struct serial_icounter_struct *icount)
388 {
389 	struct usb_serial_port *port = tty->driver_data;
390 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
391 	struct async_icount cnow = priv->icount;
392 
393 	icount->cts = cnow.cts;
394 	icount->dsr = cnow.dsr;
395 	icount->rng = cnow.rng;
396 	icount->dcd = cnow.dcd;
397 	icount->rx = cnow.rx;
398 	icount->tx = cnow.tx;
399 	icount->frame = cnow.frame;
400 	icount->overrun = cnow.overrun;
401 	icount->parity = cnow.parity;
402 	icount->brk = cnow.brk;
403 	icount->buf_overrun = cnow.buf_overrun;
404 
405 	return 0;
406 }
407 
408 
409 
410 static int ssu100_ioctl(struct tty_struct *tty,
411 		    unsigned int cmd, unsigned long arg)
412 {
413 	struct usb_serial_port *port = tty->driver_data;
414 
415 	dev_dbg(&port->dev, "%s cmd 0x%04x\n", __func__, cmd);
416 
417 	switch (cmd) {
418 	case TIOCGSERIAL:
419 		return get_serial_info(port,
420 				       (struct serial_struct __user *) arg);
421 
422 	case TIOCMIWAIT:
423 		return wait_modem_info(port, arg);
424 
425 	default:
426 		break;
427 	}
428 
429 	dev_dbg(&port->dev, "%s arg not supported\n", __func__);
430 
431 	return -ENOIOCTLCMD;
432 }
433 
434 static int ssu100_attach(struct usb_serial *serial)
435 {
436 	return ssu100_initdevice(serial->dev);
437 }
438 
439 static int ssu100_port_probe(struct usb_serial_port *port)
440 {
441 	struct ssu100_port_private *priv;
442 
443 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
444 	if (!priv)
445 		return -ENOMEM;
446 
447 	spin_lock_init(&priv->status_lock);
448 	init_waitqueue_head(&priv->delta_msr_wait);
449 
450 	usb_set_serial_port_data(port, priv);
451 
452 	return 0;
453 }
454 
455 static int ssu100_port_remove(struct usb_serial_port *port)
456 {
457 	struct ssu100_port_private *priv;
458 
459 	priv = usb_get_serial_port_data(port);
460 	kfree(priv);
461 
462 	return 0;
463 }
464 
465 static int ssu100_tiocmget(struct tty_struct *tty)
466 {
467 	struct usb_serial_port *port = tty->driver_data;
468 	struct usb_device *dev = port->serial->dev;
469 	u8 *d;
470 	int r;
471 
472 	d = kzalloc(2, GFP_KERNEL);
473 	if (!d)
474 		return -ENOMEM;
475 
476 	r = ssu100_getregister(dev, 0, UART_MCR, d);
477 	if (r < 0)
478 		goto mget_out;
479 
480 	r = ssu100_getregister(dev, 0, UART_MSR, d+1);
481 	if (r < 0)
482 		goto mget_out;
483 
484 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
485 		(d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
486 		(d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
487 		(d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
488 		(d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
489 		(d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
490 
491 mget_out:
492 	kfree(d);
493 	return r;
494 }
495 
496 static int ssu100_tiocmset(struct tty_struct *tty,
497 			   unsigned int set, unsigned int clear)
498 {
499 	struct usb_serial_port *port = tty->driver_data;
500 	struct usb_device *dev = port->serial->dev;
501 
502 	return update_mctrl(dev, set, clear);
503 }
504 
505 static void ssu100_dtr_rts(struct usb_serial_port *port, int on)
506 {
507 	struct usb_device *dev = port->serial->dev;
508 
509 	/* Disable flow control */
510 	if (!on) {
511 		if (ssu100_setregister(dev, 0, UART_MCR, 0) < 0)
512 			dev_err(&port->dev, "error from flowcontrol urb\n");
513 	}
514 	/* drop RTS and DTR */
515 	if (on)
516 		set_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
517 	else
518 		clear_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
519 }
520 
521 static void ssu100_update_msr(struct usb_serial_port *port, u8 msr)
522 {
523 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
524 	unsigned long flags;
525 
526 	spin_lock_irqsave(&priv->status_lock, flags);
527 	priv->shadowMSR = msr;
528 	spin_unlock_irqrestore(&priv->status_lock, flags);
529 
530 	if (msr & UART_MSR_ANY_DELTA) {
531 		/* update input line counters */
532 		if (msr & UART_MSR_DCTS)
533 			priv->icount.cts++;
534 		if (msr & UART_MSR_DDSR)
535 			priv->icount.dsr++;
536 		if (msr & UART_MSR_DDCD)
537 			priv->icount.dcd++;
538 		if (msr & UART_MSR_TERI)
539 			priv->icount.rng++;
540 		wake_up_interruptible(&priv->delta_msr_wait);
541 	}
542 }
543 
544 static void ssu100_update_lsr(struct usb_serial_port *port, u8 lsr,
545 			      char *tty_flag)
546 {
547 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
548 	unsigned long flags;
549 
550 	spin_lock_irqsave(&priv->status_lock, flags);
551 	priv->shadowLSR = lsr;
552 	spin_unlock_irqrestore(&priv->status_lock, flags);
553 
554 	*tty_flag = TTY_NORMAL;
555 	if (lsr & UART_LSR_BRK_ERROR_BITS) {
556 		/* we always want to update icount, but we only want to
557 		 * update tty_flag for one case */
558 		if (lsr & UART_LSR_BI) {
559 			priv->icount.brk++;
560 			*tty_flag = TTY_BREAK;
561 			usb_serial_handle_break(port);
562 		}
563 		if (lsr & UART_LSR_PE) {
564 			priv->icount.parity++;
565 			if (*tty_flag == TTY_NORMAL)
566 				*tty_flag = TTY_PARITY;
567 		}
568 		if (lsr & UART_LSR_FE) {
569 			priv->icount.frame++;
570 			if (*tty_flag == TTY_NORMAL)
571 				*tty_flag = TTY_FRAME;
572 		}
573 		if (lsr & UART_LSR_OE){
574 			priv->icount.overrun++;
575 			if (*tty_flag == TTY_NORMAL)
576 				*tty_flag = TTY_OVERRUN;
577 		}
578 	}
579 
580 }
581 
582 static void ssu100_process_read_urb(struct urb *urb)
583 {
584 	struct usb_serial_port *port = urb->context;
585 	char *packet = (char *)urb->transfer_buffer;
586 	char flag = TTY_NORMAL;
587 	u32 len = urb->actual_length;
588 	int i;
589 	char *ch;
590 
591 	if ((len >= 4) &&
592 	    (packet[0] == 0x1b) && (packet[1] == 0x1b) &&
593 	    ((packet[2] == 0x00) || (packet[2] == 0x01))) {
594 		if (packet[2] == 0x00) {
595 			ssu100_update_lsr(port, packet[3], &flag);
596 			if (flag == TTY_OVERRUN)
597 				tty_insert_flip_char(&port->port, 0,
598 						TTY_OVERRUN);
599 		}
600 		if (packet[2] == 0x01)
601 			ssu100_update_msr(port, packet[3]);
602 
603 		len -= 4;
604 		ch = packet + 4;
605 	} else
606 		ch = packet;
607 
608 	if (!len)
609 		return;	/* status only */
610 
611 	if (port->port.console && port->sysrq) {
612 		for (i = 0; i < len; i++, ch++) {
613 			if (!usb_serial_handle_sysrq_char(port, *ch))
614 				tty_insert_flip_char(&port->port, *ch, flag);
615 		}
616 	} else
617 		tty_insert_flip_string_fixed_flag(&port->port, ch, flag, len);
618 
619 	tty_flip_buffer_push(&port->port);
620 }
621 
622 static struct usb_serial_driver ssu100_device = {
623 	.driver = {
624 		.owner = THIS_MODULE,
625 		.name = "ssu100",
626 	},
627 	.description	     = DRIVER_DESC,
628 	.id_table	     = id_table,
629 	.num_ports	     = 1,
630 	.open		     = ssu100_open,
631 	.close		     = ssu100_close,
632 	.attach              = ssu100_attach,
633 	.port_probe          = ssu100_port_probe,
634 	.port_remove         = ssu100_port_remove,
635 	.dtr_rts             = ssu100_dtr_rts,
636 	.process_read_urb    = ssu100_process_read_urb,
637 	.tiocmget            = ssu100_tiocmget,
638 	.tiocmset            = ssu100_tiocmset,
639 	.get_icount	     = ssu100_get_icount,
640 	.ioctl               = ssu100_ioctl,
641 	.set_termios         = ssu100_set_termios,
642 	.disconnect          = usb_serial_generic_disconnect,
643 };
644 
645 static struct usb_serial_driver * const serial_drivers[] = {
646 	&ssu100_device, NULL
647 };
648 
649 module_usb_serial_driver(serial_drivers, id_table);
650 
651 MODULE_DESCRIPTION(DRIVER_DESC);
652 MODULE_LICENSE("GPL");
653