xref: /openbmc/linux/drivers/usb/serial/ssu100.c (revision dfc53baa)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * usb-serial driver for Quatech SSU-100
4  *
5  * based on ftdi_sio.c and the original serqt_usb.c from Quatech
6  *
7  */
8 
9 #include <linux/errno.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 	int ret;
85 
86 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
87 			      QT_SET_GET_DEVICE, 0xc0, 0, 0,
88 			      data, 3, 300);
89 	if (ret < 3) {
90 		if (ret >= 0)
91 			ret = -EIO;
92 	}
93 
94 	return ret;
95 }
96 
97 static inline int ssu100_getregister(struct usb_device *dev,
98 				     unsigned short uart,
99 				     unsigned short reg,
100 				     u8 *data)
101 {
102 	int ret;
103 
104 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
105 			      QT_SET_GET_REGISTER, 0xc0, reg,
106 			      uart, data, sizeof(*data), 300);
107 	if (ret < (int)sizeof(*data)) {
108 		if (ret >= 0)
109 			ret = -EIO;
110 	}
111 
112 	return ret;
113 }
114 
115 
116 static inline int ssu100_setregister(struct usb_device *dev,
117 				     unsigned short uart,
118 				     unsigned short reg,
119 				     u16 data)
120 {
121 	u16 value = (data << 8) | reg;
122 
123 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
124 			       QT_SET_GET_REGISTER, 0x40, value, uart,
125 			       NULL, 0, 300);
126 
127 }
128 
129 #define set_mctrl(dev, set)		update_mctrl((dev), (set), 0)
130 #define clear_mctrl(dev, clear)	update_mctrl((dev), 0, (clear))
131 
132 /* these do not deal with device that have more than 1 port */
133 static inline int update_mctrl(struct usb_device *dev, unsigned int set,
134 			       unsigned int clear)
135 {
136 	unsigned urb_value;
137 	int result;
138 
139 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
140 		dev_dbg(&dev->dev, "%s - DTR|RTS not being set|cleared\n", __func__);
141 		return 0;	/* no change */
142 	}
143 
144 	clear &= ~set;	/* 'set' takes precedence over 'clear' */
145 	urb_value = 0;
146 	if (set & TIOCM_DTR)
147 		urb_value |= UART_MCR_DTR;
148 	if (set & TIOCM_RTS)
149 		urb_value |= UART_MCR_RTS;
150 
151 	result = ssu100_setregister(dev, 0, UART_MCR, urb_value);
152 	if (result < 0)
153 		dev_dbg(&dev->dev, "%s Error from MODEM_CTRL urb\n", __func__);
154 
155 	return result;
156 }
157 
158 static int ssu100_initdevice(struct usb_device *dev)
159 {
160 	u8 *data;
161 	int result = 0;
162 
163 	data = kzalloc(3, GFP_KERNEL);
164 	if (!data)
165 		return -ENOMEM;
166 
167 	result = ssu100_getdevice(dev, data);
168 	if (result < 0) {
169 		dev_dbg(&dev->dev, "%s - get_device failed %i\n", __func__, result);
170 		goto out;
171 	}
172 
173 	data[1] &= ~FULLPWRBIT;
174 
175 	result = ssu100_setdevice(dev, data);
176 	if (result < 0) {
177 		dev_dbg(&dev->dev, "%s - setdevice failed %i\n", __func__, result);
178 		goto out;
179 	}
180 
181 	result = ssu100_control_msg(dev, QT_GET_SET_PREBUF_TRIG_LVL, 128, 0);
182 	if (result < 0) {
183 		dev_dbg(&dev->dev, "%s - set prebuffer level failed %i\n", __func__, result);
184 		goto out;
185 	}
186 
187 	result = ssu100_control_msg(dev, QT_SET_ATF, ATC_DISABLED, 0);
188 	if (result < 0) {
189 		dev_dbg(&dev->dev, "%s - set ATFprebuffer level failed %i\n", __func__, result);
190 		goto out;
191 	}
192 
193 	result = ssu100_getdevice(dev, data);
194 	if (result < 0) {
195 		dev_dbg(&dev->dev, "%s - get_device failed %i\n", __func__, result);
196 		goto out;
197 	}
198 
199 	data[0] &= ~(RR_BITS | DUPMODE_BITS);
200 	data[0] |= CLKS_X4;
201 	data[1] &= ~(LOOPMODE_BITS);
202 	data[1] |= RS232_MODE;
203 
204 	result = ssu100_setdevice(dev, data);
205 	if (result < 0) {
206 		dev_dbg(&dev->dev, "%s - setdevice failed %i\n", __func__, result);
207 		goto out;
208 	}
209 
210 out:	kfree(data);
211 	return result;
212 
213 }
214 
215 
216 static void ssu100_set_termios(struct tty_struct *tty,
217 			       struct usb_serial_port *port,
218 			       struct ktermios *old_termios)
219 {
220 	struct usb_device *dev = port->serial->dev;
221 	struct ktermios *termios = &tty->termios;
222 	u16 baud, divisor, remainder;
223 	unsigned int cflag = termios->c_cflag;
224 	u16 urb_value = 0; /* will hold the new flags */
225 	int result;
226 
227 	if (cflag & PARENB) {
228 		if (cflag & PARODD)
229 			urb_value |= UART_LCR_PARITY;
230 		else
231 			urb_value |= SERIAL_EVEN_PARITY;
232 	}
233 
234 	switch (cflag & CSIZE) {
235 	case CS5:
236 		urb_value |= UART_LCR_WLEN5;
237 		break;
238 	case CS6:
239 		urb_value |= UART_LCR_WLEN6;
240 		break;
241 	case CS7:
242 		urb_value |= UART_LCR_WLEN7;
243 		break;
244 	default:
245 	case CS8:
246 		urb_value |= UART_LCR_WLEN8;
247 		break;
248 	}
249 
250 	baud = tty_get_baud_rate(tty);
251 	if (!baud)
252 		baud = 9600;
253 
254 	dev_dbg(&port->dev, "%s - got baud = %d\n", __func__, baud);
255 
256 
257 	divisor = MAX_BAUD_RATE / baud;
258 	remainder = MAX_BAUD_RATE % baud;
259 	if (((remainder * 2) >= baud) && (baud != 110))
260 		divisor++;
261 
262 	urb_value = urb_value << 8;
263 
264 	result = ssu100_control_msg(dev, QT_GET_SET_UART, divisor, urb_value);
265 	if (result < 0)
266 		dev_dbg(&port->dev, "%s - set uart failed\n", __func__);
267 
268 	if (cflag & CRTSCTS)
269 		result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
270 					    SERIAL_CRTSCTS, 0);
271 	else
272 		result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
273 					    0, 0);
274 	if (result < 0)
275 		dev_dbg(&port->dev, "%s - set HW flow control failed\n", __func__);
276 
277 	if (I_IXOFF(tty) || I_IXON(tty)) {
278 		u16 x = ((u16)(START_CHAR(tty) << 8) | (u16)(STOP_CHAR(tty)));
279 
280 		result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
281 					    x, 0);
282 	} else
283 		result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
284 					    0, 0);
285 
286 	if (result < 0)
287 		dev_dbg(&port->dev, "%s - set SW flow control failed\n", __func__);
288 
289 }
290 
291 
292 static int ssu100_open(struct tty_struct *tty, struct usb_serial_port *port)
293 {
294 	struct usb_device *dev = port->serial->dev;
295 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
296 	u8 *data;
297 	int result;
298 	unsigned long flags;
299 
300 	data = kzalloc(2, GFP_KERNEL);
301 	if (!data)
302 		return -ENOMEM;
303 
304 	result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
305 				 QT_OPEN_CLOSE_CHANNEL,
306 				 QT_TRANSFER_IN, 0x01,
307 				 0, data, 2, 300);
308 	if (result < 2) {
309 		dev_dbg(&port->dev, "%s - open failed %i\n", __func__, result);
310 		if (result >= 0)
311 			result = -EIO;
312 		kfree(data);
313 		return result;
314 	}
315 
316 	spin_lock_irqsave(&priv->status_lock, flags);
317 	priv->shadowLSR = data[0];
318 	priv->shadowMSR = data[1];
319 	spin_unlock_irqrestore(&priv->status_lock, flags);
320 
321 	kfree(data);
322 
323 /* set to 9600 */
324 	result = ssu100_control_msg(dev, QT_GET_SET_UART, 0x30, 0x0300);
325 	if (result < 0)
326 		dev_dbg(&port->dev, "%s - set uart failed\n", __func__);
327 
328 	if (tty)
329 		ssu100_set_termios(tty, port, &tty->termios);
330 
331 	return usb_serial_generic_open(tty, port);
332 }
333 
334 static int get_serial_info(struct tty_struct *tty,
335 			   struct serial_struct *ss)
336 {
337 	struct usb_serial_port *port = tty->driver_data;
338 
339 	ss->line		= port->minor;
340 	ss->port		= 0;
341 	ss->irq			= 0;
342 	ss->xmit_fifo_size	= port->bulk_out_size;
343 	ss->baud_base		= 9600;
344 	ss->close_delay		= 5*HZ;
345 	ss->closing_wait	= 30*HZ;
346 	return 0;
347 }
348 
349 static int ssu100_attach(struct usb_serial *serial)
350 {
351 	return ssu100_initdevice(serial->dev);
352 }
353 
354 static int ssu100_port_probe(struct usb_serial_port *port)
355 {
356 	struct ssu100_port_private *priv;
357 
358 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
359 	if (!priv)
360 		return -ENOMEM;
361 
362 	spin_lock_init(&priv->status_lock);
363 
364 	usb_set_serial_port_data(port, priv);
365 
366 	return 0;
367 }
368 
369 static int ssu100_port_remove(struct usb_serial_port *port)
370 {
371 	struct ssu100_port_private *priv;
372 
373 	priv = usb_get_serial_port_data(port);
374 	kfree(priv);
375 
376 	return 0;
377 }
378 
379 static int ssu100_tiocmget(struct tty_struct *tty)
380 {
381 	struct usb_serial_port *port = tty->driver_data;
382 	struct usb_device *dev = port->serial->dev;
383 	u8 *d;
384 	int r;
385 
386 	d = kzalloc(2, GFP_KERNEL);
387 	if (!d)
388 		return -ENOMEM;
389 
390 	r = ssu100_getregister(dev, 0, UART_MCR, d);
391 	if (r < 0)
392 		goto mget_out;
393 
394 	r = ssu100_getregister(dev, 0, UART_MSR, d+1);
395 	if (r < 0)
396 		goto mget_out;
397 
398 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
399 		(d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
400 		(d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
401 		(d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
402 		(d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
403 		(d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
404 
405 mget_out:
406 	kfree(d);
407 	return r;
408 }
409 
410 static int ssu100_tiocmset(struct tty_struct *tty,
411 			   unsigned int set, unsigned int clear)
412 {
413 	struct usb_serial_port *port = tty->driver_data;
414 	struct usb_device *dev = port->serial->dev;
415 
416 	return update_mctrl(dev, set, clear);
417 }
418 
419 static void ssu100_dtr_rts(struct usb_serial_port *port, int on)
420 {
421 	struct usb_device *dev = port->serial->dev;
422 
423 	/* Disable flow control */
424 	if (!on) {
425 		if (ssu100_setregister(dev, 0, UART_MCR, 0) < 0)
426 			dev_err(&port->dev, "error from flowcontrol urb\n");
427 	}
428 	/* drop RTS and DTR */
429 	if (on)
430 		set_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
431 	else
432 		clear_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
433 }
434 
435 static void ssu100_update_msr(struct usb_serial_port *port, u8 msr)
436 {
437 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
438 	unsigned long flags;
439 
440 	spin_lock_irqsave(&priv->status_lock, flags);
441 	priv->shadowMSR = msr;
442 	spin_unlock_irqrestore(&priv->status_lock, flags);
443 
444 	if (msr & UART_MSR_ANY_DELTA) {
445 		/* update input line counters */
446 		if (msr & UART_MSR_DCTS)
447 			port->icount.cts++;
448 		if (msr & UART_MSR_DDSR)
449 			port->icount.dsr++;
450 		if (msr & UART_MSR_DDCD)
451 			port->icount.dcd++;
452 		if (msr & UART_MSR_TERI)
453 			port->icount.rng++;
454 		wake_up_interruptible(&port->port.delta_msr_wait);
455 	}
456 }
457 
458 static void ssu100_update_lsr(struct usb_serial_port *port, u8 lsr,
459 			      char *tty_flag)
460 {
461 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
462 	unsigned long flags;
463 
464 	spin_lock_irqsave(&priv->status_lock, flags);
465 	priv->shadowLSR = lsr;
466 	spin_unlock_irqrestore(&priv->status_lock, flags);
467 
468 	*tty_flag = TTY_NORMAL;
469 	if (lsr & UART_LSR_BRK_ERROR_BITS) {
470 		/* we always want to update icount, but we only want to
471 		 * update tty_flag for one case */
472 		if (lsr & UART_LSR_BI) {
473 			port->icount.brk++;
474 			*tty_flag = TTY_BREAK;
475 			usb_serial_handle_break(port);
476 		}
477 		if (lsr & UART_LSR_PE) {
478 			port->icount.parity++;
479 			if (*tty_flag == TTY_NORMAL)
480 				*tty_flag = TTY_PARITY;
481 		}
482 		if (lsr & UART_LSR_FE) {
483 			port->icount.frame++;
484 			if (*tty_flag == TTY_NORMAL)
485 				*tty_flag = TTY_FRAME;
486 		}
487 		if (lsr & UART_LSR_OE) {
488 			port->icount.overrun++;
489 			tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
490 		}
491 	}
492 
493 }
494 
495 static void ssu100_process_read_urb(struct urb *urb)
496 {
497 	struct usb_serial_port *port = urb->context;
498 	char *packet = urb->transfer_buffer;
499 	char flag = TTY_NORMAL;
500 	u32 len = urb->actual_length;
501 	int i;
502 	char *ch;
503 
504 	if ((len >= 4) &&
505 	    (packet[0] == 0x1b) && (packet[1] == 0x1b) &&
506 	    ((packet[2] == 0x00) || (packet[2] == 0x01))) {
507 		if (packet[2] == 0x00)
508 			ssu100_update_lsr(port, packet[3], &flag);
509 		if (packet[2] == 0x01)
510 			ssu100_update_msr(port, packet[3]);
511 
512 		len -= 4;
513 		ch = packet + 4;
514 	} else
515 		ch = packet;
516 
517 	if (!len)
518 		return;	/* status only */
519 
520 	if (port->sysrq) {
521 		for (i = 0; i < len; i++, ch++) {
522 			if (!usb_serial_handle_sysrq_char(port, *ch))
523 				tty_insert_flip_char(&port->port, *ch, flag);
524 		}
525 	} else {
526 		tty_insert_flip_string_fixed_flag(&port->port, ch, flag, len);
527 	}
528 
529 	tty_flip_buffer_push(&port->port);
530 }
531 
532 static struct usb_serial_driver ssu100_device = {
533 	.driver = {
534 		.owner = THIS_MODULE,
535 		.name = "ssu100",
536 	},
537 	.description	     = DRIVER_DESC,
538 	.id_table	     = id_table,
539 	.num_ports	     = 1,
540 	.open		     = ssu100_open,
541 	.attach              = ssu100_attach,
542 	.port_probe          = ssu100_port_probe,
543 	.port_remove         = ssu100_port_remove,
544 	.dtr_rts             = ssu100_dtr_rts,
545 	.process_read_urb    = ssu100_process_read_urb,
546 	.tiocmget            = ssu100_tiocmget,
547 	.tiocmset            = ssu100_tiocmset,
548 	.tiocmiwait          = usb_serial_generic_tiocmiwait,
549 	.get_icount	     = usb_serial_generic_get_icount,
550 	.get_serial          = get_serial_info,
551 	.set_termios         = ssu100_set_termios,
552 };
553 
554 static struct usb_serial_driver * const serial_drivers[] = {
555 	&ssu100_device, NULL
556 };
557 
558 module_usb_serial_driver(serial_drivers, id_table);
559 
560 MODULE_DESCRIPTION(DRIVER_DESC);
561 MODULE_LICENSE("GPL v2");
562