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
54static const struct usb_device_id id_table[] = {
55	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU100)},
56	{}			/* Terminating entry */
57};
58MODULE_DEVICE_TABLE(usb, id_table);
59
60struct ssu100_port_private {
61	spinlock_t status_lock;
62	u8 shadowLSR;
63	u8 shadowMSR;
64};
65
66static 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
74static 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
82static 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
97static 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
116static 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 */
133static 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
158static 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
210out:	kfree(data);
211	return result;
212
213}
214
215
216static 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
278static 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
320static int ssu100_attach(struct usb_serial *serial)
321{
322	return ssu100_initdevice(serial->dev);
323}
324
325static 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
340static 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
348static 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
374mget_out:
375	kfree(d);
376	return r;
377}
378
379static 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
388static 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
404static 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
427static 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
464static 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
501static 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
522static struct usb_serial_driver * const serial_drivers[] = {
523	&ssu100_device, NULL
524};
525
526module_usb_serial_driver(serial_drivers, id_table);
527
528MODULE_DESCRIPTION(DRIVER_DESC);
529MODULE_LICENSE("GPL v2");
530