xref: /openbmc/linux/drivers/usb/serial/ssu100.c (revision 0d727e18)
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 		               const 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 	urb_value |= UART_LCR_WLEN(tty_get_char_size(cflag));
235 
236 	baud = tty_get_baud_rate(tty);
237 	if (!baud)
238 		baud = 9600;
239 
240 	dev_dbg(&port->dev, "%s - got baud = %d\n", __func__, baud);
241 
242 
243 	divisor = MAX_BAUD_RATE / baud;
244 	remainder = MAX_BAUD_RATE % baud;
245 	if (((remainder * 2) >= baud) && (baud != 110))
246 		divisor++;
247 
248 	urb_value = urb_value << 8;
249 
250 	result = ssu100_control_msg(dev, QT_GET_SET_UART, divisor, urb_value);
251 	if (result < 0)
252 		dev_dbg(&port->dev, "%s - set uart failed\n", __func__);
253 
254 	if (cflag & CRTSCTS)
255 		result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
256 					    SERIAL_CRTSCTS, 0);
257 	else
258 		result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
259 					    0, 0);
260 	if (result < 0)
261 		dev_dbg(&port->dev, "%s - set HW flow control failed\n", __func__);
262 
263 	if (I_IXOFF(tty) || I_IXON(tty)) {
264 		u16 x = ((u16)(START_CHAR(tty) << 8) | (u16)(STOP_CHAR(tty)));
265 
266 		result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
267 					    x, 0);
268 	} else
269 		result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
270 					    0, 0);
271 
272 	if (result < 0)
273 		dev_dbg(&port->dev, "%s - set SW flow control failed\n", __func__);
274 
275 }
276 
277 
278 static int ssu100_open(struct tty_struct *tty, struct usb_serial_port *port)
279 {
280 	struct usb_device *dev = port->serial->dev;
281 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
282 	u8 *data;
283 	int result;
284 	unsigned long flags;
285 
286 	data = kzalloc(2, GFP_KERNEL);
287 	if (!data)
288 		return -ENOMEM;
289 
290 	result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
291 				 QT_OPEN_CLOSE_CHANNEL,
292 				 QT_TRANSFER_IN, 0x01,
293 				 0, data, 2, 300);
294 	if (result < 2) {
295 		dev_dbg(&port->dev, "%s - open failed %i\n", __func__, result);
296 		if (result >= 0)
297 			result = -EIO;
298 		kfree(data);
299 		return result;
300 	}
301 
302 	spin_lock_irqsave(&priv->status_lock, flags);
303 	priv->shadowLSR = data[0];
304 	priv->shadowMSR = data[1];
305 	spin_unlock_irqrestore(&priv->status_lock, flags);
306 
307 	kfree(data);
308 
309 /* set to 9600 */
310 	result = ssu100_control_msg(dev, QT_GET_SET_UART, 0x30, 0x0300);
311 	if (result < 0)
312 		dev_dbg(&port->dev, "%s - set uart failed\n", __func__);
313 
314 	if (tty)
315 		ssu100_set_termios(tty, port, &tty->termios);
316 
317 	return usb_serial_generic_open(tty, port);
318 }
319 
320 static int ssu100_attach(struct usb_serial *serial)
321 {
322 	return ssu100_initdevice(serial->dev);
323 }
324 
325 static int ssu100_port_probe(struct usb_serial_port *port)
326 {
327 	struct ssu100_port_private *priv;
328 
329 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
330 	if (!priv)
331 		return -ENOMEM;
332 
333 	spin_lock_init(&priv->status_lock);
334 
335 	usb_set_serial_port_data(port, priv);
336 
337 	return 0;
338 }
339 
340 static void ssu100_port_remove(struct usb_serial_port *port)
341 {
342 	struct ssu100_port_private *priv;
343 
344 	priv = usb_get_serial_port_data(port);
345 	kfree(priv);
346 }
347 
348 static int ssu100_tiocmget(struct tty_struct *tty)
349 {
350 	struct usb_serial_port *port = tty->driver_data;
351 	struct usb_device *dev = port->serial->dev;
352 	u8 *d;
353 	int r;
354 
355 	d = kzalloc(2, GFP_KERNEL);
356 	if (!d)
357 		return -ENOMEM;
358 
359 	r = ssu100_getregister(dev, 0, UART_MCR, d);
360 	if (r < 0)
361 		goto mget_out;
362 
363 	r = ssu100_getregister(dev, 0, UART_MSR, d+1);
364 	if (r < 0)
365 		goto mget_out;
366 
367 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
368 		(d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
369 		(d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
370 		(d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
371 		(d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
372 		(d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
373 
374 mget_out:
375 	kfree(d);
376 	return r;
377 }
378 
379 static int ssu100_tiocmset(struct tty_struct *tty,
380 			   unsigned int set, unsigned int clear)
381 {
382 	struct usb_serial_port *port = tty->driver_data;
383 	struct usb_device *dev = port->serial->dev;
384 
385 	return update_mctrl(dev, set, clear);
386 }
387 
388 static void ssu100_dtr_rts(struct usb_serial_port *port, int on)
389 {
390 	struct usb_device *dev = port->serial->dev;
391 
392 	/* Disable flow control */
393 	if (!on) {
394 		if (ssu100_setregister(dev, 0, UART_MCR, 0) < 0)
395 			dev_err(&port->dev, "error from flowcontrol urb\n");
396 	}
397 	/* drop RTS and DTR */
398 	if (on)
399 		set_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
400 	else
401 		clear_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
402 }
403 
404 static void ssu100_update_msr(struct usb_serial_port *port, u8 msr)
405 {
406 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
407 	unsigned long flags;
408 
409 	spin_lock_irqsave(&priv->status_lock, flags);
410 	priv->shadowMSR = msr;
411 	spin_unlock_irqrestore(&priv->status_lock, flags);
412 
413 	if (msr & UART_MSR_ANY_DELTA) {
414 		/* update input line counters */
415 		if (msr & UART_MSR_DCTS)
416 			port->icount.cts++;
417 		if (msr & UART_MSR_DDSR)
418 			port->icount.dsr++;
419 		if (msr & UART_MSR_DDCD)
420 			port->icount.dcd++;
421 		if (msr & UART_MSR_TERI)
422 			port->icount.rng++;
423 		wake_up_interruptible(&port->port.delta_msr_wait);
424 	}
425 }
426 
427 static void ssu100_update_lsr(struct usb_serial_port *port, u8 lsr,
428 			      char *tty_flag)
429 {
430 	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
431 	unsigned long flags;
432 
433 	spin_lock_irqsave(&priv->status_lock, flags);
434 	priv->shadowLSR = lsr;
435 	spin_unlock_irqrestore(&priv->status_lock, flags);
436 
437 	*tty_flag = TTY_NORMAL;
438 	if (lsr & UART_LSR_BRK_ERROR_BITS) {
439 		/* we always want to update icount, but we only want to
440 		 * update tty_flag for one case */
441 		if (lsr & UART_LSR_BI) {
442 			port->icount.brk++;
443 			*tty_flag = TTY_BREAK;
444 			usb_serial_handle_break(port);
445 		}
446 		if (lsr & UART_LSR_PE) {
447 			port->icount.parity++;
448 			if (*tty_flag == TTY_NORMAL)
449 				*tty_flag = TTY_PARITY;
450 		}
451 		if (lsr & UART_LSR_FE) {
452 			port->icount.frame++;
453 			if (*tty_flag == TTY_NORMAL)
454 				*tty_flag = TTY_FRAME;
455 		}
456 		if (lsr & UART_LSR_OE) {
457 			port->icount.overrun++;
458 			tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
459 		}
460 	}
461 
462 }
463 
464 static void ssu100_process_read_urb(struct urb *urb)
465 {
466 	struct usb_serial_port *port = urb->context;
467 	char *packet = urb->transfer_buffer;
468 	char flag = TTY_NORMAL;
469 	u32 len = urb->actual_length;
470 	int i;
471 	char *ch;
472 
473 	if ((len >= 4) &&
474 	    (packet[0] == 0x1b) && (packet[1] == 0x1b) &&
475 	    ((packet[2] == 0x00) || (packet[2] == 0x01))) {
476 		if (packet[2] == 0x00)
477 			ssu100_update_lsr(port, packet[3], &flag);
478 		if (packet[2] == 0x01)
479 			ssu100_update_msr(port, packet[3]);
480 
481 		len -= 4;
482 		ch = packet + 4;
483 	} else
484 		ch = packet;
485 
486 	if (!len)
487 		return;	/* status only */
488 
489 	if (port->sysrq) {
490 		for (i = 0; i < len; i++, ch++) {
491 			if (!usb_serial_handle_sysrq_char(port, *ch))
492 				tty_insert_flip_char(&port->port, *ch, flag);
493 		}
494 	} else {
495 		tty_insert_flip_string_fixed_flag(&port->port, ch, flag, len);
496 	}
497 
498 	tty_flip_buffer_push(&port->port);
499 }
500 
501 static struct usb_serial_driver ssu100_device = {
502 	.driver = {
503 		.owner = THIS_MODULE,
504 		.name = "ssu100",
505 	},
506 	.description	     = DRIVER_DESC,
507 	.id_table	     = id_table,
508 	.num_ports	     = 1,
509 	.open		     = ssu100_open,
510 	.attach              = ssu100_attach,
511 	.port_probe          = ssu100_port_probe,
512 	.port_remove         = ssu100_port_remove,
513 	.dtr_rts             = ssu100_dtr_rts,
514 	.process_read_urb    = ssu100_process_read_urb,
515 	.tiocmget            = ssu100_tiocmget,
516 	.tiocmset            = ssu100_tiocmset,
517 	.tiocmiwait          = usb_serial_generic_tiocmiwait,
518 	.get_icount	     = usb_serial_generic_get_icount,
519 	.set_termios         = ssu100_set_termios,
520 };
521 
522 static struct usb_serial_driver * const serial_drivers[] = {
523 	&ssu100_device, NULL
524 };
525 
526 module_usb_serial_driver(serial_drivers, id_table);
527 
528 MODULE_DESCRIPTION(DRIVER_DESC);
529 MODULE_LICENSE("GPL v2");
530