xref: /openbmc/linux/drivers/usb/serial/ssu100.c (revision 39b6f3aa)
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 };
65 
66 static inline int ssu100_control_msg(struct usb_device *dev,
67 				     u8 request, u16 data, u16 index)
68 {
69 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
70 			       request, 0x40, data, index,
71 			       NULL, 0, 300);
72 }
73 
74 static inline int ssu100_setdevice(struct usb_device *dev, u8 *data)
75 {
76 	u16 x = ((u16)(data[1] << 8) | (u16)(data[0]));
77 
78 	return ssu100_control_msg(dev, QT_SET_GET_DEVICE, x, 0);
79 }
80 
81 
82 static inline int ssu100_getdevice(struct usb_device *dev, u8 *data)
83 {
84 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
85 			       QT_SET_GET_DEVICE, 0xc0, 0, 0,
86 			       data, 3, 300);
87 }
88 
89 static inline int ssu100_getregister(struct usb_device *dev,
90 				     unsigned short uart,
91 				     unsigned short reg,
92 				     u8 *data)
93 {
94 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
95 			       QT_SET_GET_REGISTER, 0xc0, reg,
96 			       uart, data, sizeof(*data), 300);
97 
98 }
99 
100 
101 static inline int ssu100_setregister(struct usb_device *dev,
102 				     unsigned short uart,
103 				     unsigned short reg,
104 				     u16 data)
105 {
106 	u16 value = (data << 8) | reg;
107 
108 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
109 			       QT_SET_GET_REGISTER, 0x40, value, uart,
110 			       NULL, 0, 300);
111 
112 }
113 
114 #define set_mctrl(dev, set)		update_mctrl((dev), (set), 0)
115 #define clear_mctrl(dev, clear)	update_mctrl((dev), 0, (clear))
116 
117 /* these do not deal with device that have more than 1 port */
118 static inline int update_mctrl(struct usb_device *dev, unsigned int set,
119 			       unsigned int clear)
120 {
121 	unsigned urb_value;
122 	int result;
123 
124 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
125 		dev_dbg(&dev->dev, "%s - DTR|RTS not being set|cleared\n", __func__);
126 		return 0;	/* no change */
127 	}
128 
129 	clear &= ~set;	/* 'set' takes precedence over 'clear' */
130 	urb_value = 0;
131 	if (set & TIOCM_DTR)
132 		urb_value |= UART_MCR_DTR;
133 	if (set & TIOCM_RTS)
134 		urb_value |= UART_MCR_RTS;
135 
136 	result = ssu100_setregister(dev, 0, UART_MCR, urb_value);
137 	if (result < 0)
138 		dev_dbg(&dev->dev, "%s Error from MODEM_CTRL urb\n", __func__);
139 
140 	return result;
141 }
142 
143 static int ssu100_initdevice(struct usb_device *dev)
144 {
145 	u8 *data;
146 	int result = 0;
147 
148 	data = kzalloc(3, GFP_KERNEL);
149 	if (!data)
150 		return -ENOMEM;
151 
152 	result = ssu100_getdevice(dev, data);
153 	if (result < 0) {
154 		dev_dbg(&dev->dev, "%s - get_device failed %i\n", __func__, result);
155 		goto out;
156 	}
157 
158 	data[1] &= ~FULLPWRBIT;
159 
160 	result = ssu100_setdevice(dev, data);
161 	if (result < 0) {
162 		dev_dbg(&dev->dev, "%s - setdevice failed %i\n", __func__, result);
163 		goto out;
164 	}
165 
166 	result = ssu100_control_msg(dev, QT_GET_SET_PREBUF_TRIG_LVL, 128, 0);
167 	if (result < 0) {
168 		dev_dbg(&dev->dev, "%s - set prebuffer level failed %i\n", __func__, result);
169 		goto out;
170 	}
171 
172 	result = ssu100_control_msg(dev, QT_SET_ATF, ATC_DISABLED, 0);
173 	if (result < 0) {
174 		dev_dbg(&dev->dev, "%s - set ATFprebuffer level failed %i\n", __func__, result);
175 		goto out;
176 	}
177 
178 	result = ssu100_getdevice(dev, data);
179 	if (result < 0) {
180 		dev_dbg(&dev->dev, "%s - get_device failed %i\n", __func__, result);
181 		goto out;
182 	}
183 
184 	data[0] &= ~(RR_BITS | DUPMODE_BITS);
185 	data[0] |= CLKS_X4;
186 	data[1] &= ~(LOOPMODE_BITS);
187 	data[1] |= RS232_MODE;
188 
189 	result = ssu100_setdevice(dev, data);
190 	if (result < 0) {
191 		dev_dbg(&dev->dev, "%s - setdevice failed %i\n", __func__, result);
192 		goto out;
193 	}
194 
195 out:	kfree(data);
196 	return result;
197 
198 }
199 
200 
201 static void ssu100_set_termios(struct tty_struct *tty,
202 			       struct usb_serial_port *port,
203 			       struct ktermios *old_termios)
204 {
205 	struct usb_device *dev = port->serial->dev;
206 	struct ktermios *termios = &tty->termios;
207 	u16 baud, divisor, remainder;
208 	unsigned int cflag = termios->c_cflag;
209 	u16 urb_value = 0; /* will hold the new flags */
210 	int result;
211 
212 	if (cflag & PARENB) {
213 		if (cflag & PARODD)
214 			urb_value |= UART_LCR_PARITY;
215 		else
216 			urb_value |= SERIAL_EVEN_PARITY;
217 	}
218 
219 	switch (cflag & CSIZE) {
220 	case CS5:
221 		urb_value |= UART_LCR_WLEN5;
222 		break;
223 	case CS6:
224 		urb_value |= UART_LCR_WLEN6;
225 		break;
226 	case CS7:
227 		urb_value |= UART_LCR_WLEN7;
228 		break;
229 	default:
230 	case CS8:
231 		urb_value |= UART_LCR_WLEN8;
232 		break;
233 	}
234 
235 	baud = tty_get_baud_rate(tty);
236 	if (!baud)
237 		baud = 9600;
238 
239 	dev_dbg(&port->dev, "%s - got baud = %d\n", __func__, baud);
240 
241 
242 	divisor = MAX_BAUD_RATE / baud;
243 	remainder = MAX_BAUD_RATE % baud;
244 	if (((remainder * 2) >= baud) && (baud != 110))
245 		divisor++;
246 
247 	urb_value = urb_value << 8;
248 
249 	result = ssu100_control_msg(dev, QT_GET_SET_UART, divisor, urb_value);
250 	if (result < 0)
251 		dev_dbg(&port->dev, "%s - set uart failed\n", __func__);
252 
253 	if (cflag & CRTSCTS)
254 		result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
255 					    SERIAL_CRTSCTS, 0);
256 	else
257 		result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
258 					    0, 0);
259 	if (result < 0)
260 		dev_dbg(&port->dev, "%s - set HW flow control failed\n", __func__);
261 
262 	if (I_IXOFF(tty) || I_IXON(tty)) {
263 		u16 x = ((u16)(START_CHAR(tty) << 8) | (u16)(STOP_CHAR(tty)));
264 
265 		result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
266 					    x, 0);
267 	} else
268 		result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
269 					    0, 0);
270 
271 	if (result < 0)
272 		dev_dbg(&port->dev, "%s - set SW flow control failed\n", __func__);
273 
274 }
275 
276 
277 static int ssu100_open(struct tty_struct *tty, struct usb_serial_port *port)
278 {
279 	struct usb_device *dev = port->serial->dev;
280 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
281 	u8 *data;
282 	int result;
283 	unsigned long flags;
284 
285 	data = kzalloc(2, GFP_KERNEL);
286 	if (!data)
287 		return -ENOMEM;
288 
289 	result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
290 				 QT_OPEN_CLOSE_CHANNEL,
291 				 QT_TRANSFER_IN, 0x01,
292 				 0, data, 2, 300);
293 	if (result < 0) {
294 		dev_dbg(&port->dev, "%s - open failed %i\n", __func__, result);
295 		kfree(data);
296 		return result;
297 	}
298 
299 	spin_lock_irqsave(&priv->status_lock, flags);
300 	priv->shadowLSR = data[0];
301 	priv->shadowMSR = data[1];
302 	spin_unlock_irqrestore(&priv->status_lock, flags);
303 
304 	kfree(data);
305 
306 /* set to 9600 */
307 	result = ssu100_control_msg(dev, QT_GET_SET_UART, 0x30, 0x0300);
308 	if (result < 0)
309 		dev_dbg(&port->dev, "%s - set uart failed\n", __func__);
310 
311 	if (tty)
312 		ssu100_set_termios(tty, port, &tty->termios);
313 
314 	return usb_serial_generic_open(tty, port);
315 }
316 
317 static int get_serial_info(struct usb_serial_port *port,
318 			   struct serial_struct __user *retinfo)
319 {
320 	struct serial_struct tmp;
321 
322 	if (!retinfo)
323 		return -EFAULT;
324 
325 	memset(&tmp, 0, sizeof(tmp));
326 	tmp.line		= port->serial->minor;
327 	tmp.port		= 0;
328 	tmp.irq			= 0;
329 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
330 	tmp.xmit_fifo_size	= port->bulk_out_size;
331 	tmp.baud_base		= 9600;
332 	tmp.close_delay		= 5*HZ;
333 	tmp.closing_wait	= 30*HZ;
334 
335 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
336 		return -EFAULT;
337 	return 0;
338 }
339 
340 static int ssu100_ioctl(struct tty_struct *tty,
341 		    unsigned int cmd, unsigned long arg)
342 {
343 	struct usb_serial_port *port = tty->driver_data;
344 
345 	dev_dbg(&port->dev, "%s cmd 0x%04x\n", __func__, cmd);
346 
347 	switch (cmd) {
348 	case TIOCGSERIAL:
349 		return get_serial_info(port,
350 				       (struct serial_struct __user *) arg);
351 	default:
352 		break;
353 	}
354 
355 	dev_dbg(&port->dev, "%s arg not supported\n", __func__);
356 
357 	return -ENOIOCTLCMD;
358 }
359 
360 static int ssu100_attach(struct usb_serial *serial)
361 {
362 	return ssu100_initdevice(serial->dev);
363 }
364 
365 static int ssu100_port_probe(struct usb_serial_port *port)
366 {
367 	struct ssu100_port_private *priv;
368 
369 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
370 	if (!priv)
371 		return -ENOMEM;
372 
373 	spin_lock_init(&priv->status_lock);
374 
375 	usb_set_serial_port_data(port, priv);
376 
377 	return 0;
378 }
379 
380 static int ssu100_port_remove(struct usb_serial_port *port)
381 {
382 	struct ssu100_port_private *priv;
383 
384 	priv = usb_get_serial_port_data(port);
385 	kfree(priv);
386 
387 	return 0;
388 }
389 
390 static int ssu100_tiocmget(struct tty_struct *tty)
391 {
392 	struct usb_serial_port *port = tty->driver_data;
393 	struct usb_device *dev = port->serial->dev;
394 	u8 *d;
395 	int r;
396 
397 	d = kzalloc(2, GFP_KERNEL);
398 	if (!d)
399 		return -ENOMEM;
400 
401 	r = ssu100_getregister(dev, 0, UART_MCR, d);
402 	if (r < 0)
403 		goto mget_out;
404 
405 	r = ssu100_getregister(dev, 0, UART_MSR, d+1);
406 	if (r < 0)
407 		goto mget_out;
408 
409 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
410 		(d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
411 		(d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
412 		(d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
413 		(d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
414 		(d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
415 
416 mget_out:
417 	kfree(d);
418 	return r;
419 }
420 
421 static int ssu100_tiocmset(struct tty_struct *tty,
422 			   unsigned int set, unsigned int clear)
423 {
424 	struct usb_serial_port *port = tty->driver_data;
425 	struct usb_device *dev = port->serial->dev;
426 
427 	return update_mctrl(dev, set, clear);
428 }
429 
430 static void ssu100_dtr_rts(struct usb_serial_port *port, int on)
431 {
432 	struct usb_device *dev = port->serial->dev;
433 
434 	/* Disable flow control */
435 	if (!on) {
436 		if (ssu100_setregister(dev, 0, UART_MCR, 0) < 0)
437 			dev_err(&port->dev, "error from flowcontrol urb\n");
438 	}
439 	/* drop RTS and DTR */
440 	if (on)
441 		set_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
442 	else
443 		clear_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
444 }
445 
446 static void ssu100_update_msr(struct usb_serial_port *port, u8 msr)
447 {
448 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
449 	unsigned long flags;
450 
451 	spin_lock_irqsave(&priv->status_lock, flags);
452 	priv->shadowMSR = msr;
453 	spin_unlock_irqrestore(&priv->status_lock, flags);
454 
455 	if (msr & UART_MSR_ANY_DELTA) {
456 		/* update input line counters */
457 		if (msr & UART_MSR_DCTS)
458 			port->icount.cts++;
459 		if (msr & UART_MSR_DDSR)
460 			port->icount.dsr++;
461 		if (msr & UART_MSR_DDCD)
462 			port->icount.dcd++;
463 		if (msr & UART_MSR_TERI)
464 			port->icount.rng++;
465 		wake_up_interruptible(&port->port.delta_msr_wait);
466 	}
467 }
468 
469 static void ssu100_update_lsr(struct usb_serial_port *port, u8 lsr,
470 			      char *tty_flag)
471 {
472 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
473 	unsigned long flags;
474 
475 	spin_lock_irqsave(&priv->status_lock, flags);
476 	priv->shadowLSR = lsr;
477 	spin_unlock_irqrestore(&priv->status_lock, flags);
478 
479 	*tty_flag = TTY_NORMAL;
480 	if (lsr & UART_LSR_BRK_ERROR_BITS) {
481 		/* we always want to update icount, but we only want to
482 		 * update tty_flag for one case */
483 		if (lsr & UART_LSR_BI) {
484 			port->icount.brk++;
485 			*tty_flag = TTY_BREAK;
486 			usb_serial_handle_break(port);
487 		}
488 		if (lsr & UART_LSR_PE) {
489 			port->icount.parity++;
490 			if (*tty_flag == TTY_NORMAL)
491 				*tty_flag = TTY_PARITY;
492 		}
493 		if (lsr & UART_LSR_FE) {
494 			port->icount.frame++;
495 			if (*tty_flag == TTY_NORMAL)
496 				*tty_flag = TTY_FRAME;
497 		}
498 		if (lsr & UART_LSR_OE){
499 			port->icount.overrun++;
500 			if (*tty_flag == TTY_NORMAL)
501 				*tty_flag = TTY_OVERRUN;
502 		}
503 	}
504 
505 }
506 
507 static void ssu100_process_read_urb(struct urb *urb)
508 {
509 	struct usb_serial_port *port = urb->context;
510 	char *packet = (char *)urb->transfer_buffer;
511 	char flag = TTY_NORMAL;
512 	u32 len = urb->actual_length;
513 	int i;
514 	char *ch;
515 
516 	if ((len >= 4) &&
517 	    (packet[0] == 0x1b) && (packet[1] == 0x1b) &&
518 	    ((packet[2] == 0x00) || (packet[2] == 0x01))) {
519 		if (packet[2] == 0x00) {
520 			ssu100_update_lsr(port, packet[3], &flag);
521 			if (flag == TTY_OVERRUN)
522 				tty_insert_flip_char(&port->port, 0,
523 						TTY_OVERRUN);
524 		}
525 		if (packet[2] == 0x01)
526 			ssu100_update_msr(port, packet[3]);
527 
528 		len -= 4;
529 		ch = packet + 4;
530 	} else
531 		ch = packet;
532 
533 	if (!len)
534 		return;	/* status only */
535 
536 	if (port->port.console && port->sysrq) {
537 		for (i = 0; i < len; i++, ch++) {
538 			if (!usb_serial_handle_sysrq_char(port, *ch))
539 				tty_insert_flip_char(&port->port, *ch, flag);
540 		}
541 	} else
542 		tty_insert_flip_string_fixed_flag(&port->port, ch, flag, len);
543 
544 	tty_flip_buffer_push(&port->port);
545 }
546 
547 static struct usb_serial_driver ssu100_device = {
548 	.driver = {
549 		.owner = THIS_MODULE,
550 		.name = "ssu100",
551 	},
552 	.description	     = DRIVER_DESC,
553 	.id_table	     = id_table,
554 	.num_ports	     = 1,
555 	.open		     = ssu100_open,
556 	.attach              = ssu100_attach,
557 	.port_probe          = ssu100_port_probe,
558 	.port_remove         = ssu100_port_remove,
559 	.dtr_rts             = ssu100_dtr_rts,
560 	.process_read_urb    = ssu100_process_read_urb,
561 	.tiocmget            = ssu100_tiocmget,
562 	.tiocmset            = ssu100_tiocmset,
563 	.tiocmiwait          = usb_serial_generic_tiocmiwait,
564 	.get_icount	     = usb_serial_generic_get_icount,
565 	.ioctl               = ssu100_ioctl,
566 	.set_termios         = ssu100_set_termios,
567 };
568 
569 static struct usb_serial_driver * const serial_drivers[] = {
570 	&ssu100_device, NULL
571 };
572 
573 module_usb_serial_driver(serial_drivers, id_table);
574 
575 MODULE_DESCRIPTION(DRIVER_DESC);
576 MODULE_LICENSE("GPL");
577