xref: /linux/drivers/usb/serial/cp210x.c (revision d2ad67b3fa61eed52b22491210c668a94c7bf17e)
1 /*
2  * Silicon Laboratories CP2101/CP2102 USB to RS232 serial adaptor driver
3  *
4  * Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License version
8  *	2 as published by the Free Software Foundation.
9  *
10  * Support to set flow control line levels using TIOCMGET and TIOCMSET
11  * thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow
12  * control thanks to Munir Nassar nassarmu@real-time.com
13  *
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/errno.h>
18 #include <linux/slab.h>
19 #include <linux/tty.h>
20 #include <linux/tty_flip.h>
21 #include <linux/module.h>
22 #include <linux/moduleparam.h>
23 #include <linux/usb.h>
24 #include <linux/uaccess.h>
25 #include <linux/usb/serial.h>
26 
27 /*
28  * Version Information
29  */
30 #define DRIVER_VERSION "v0.08"
31 #define DRIVER_DESC "Silicon Labs CP2101/CP2102 RS232 serial adaptor driver"
32 
33 /*
34  * Function Prototypes
35  */
36 static int cp2101_open(struct tty_struct *, struct usb_serial_port *,
37 							struct file *);
38 static void cp2101_cleanup(struct usb_serial_port *);
39 static void cp2101_close(struct tty_struct *, struct usb_serial_port *,
40 							struct file*);
41 static void cp2101_get_termios(struct tty_struct *,
42 	struct usb_serial_port *port);
43 static void cp2101_get_termios_port(struct usb_serial_port *port,
44 	unsigned int *cflagp, unsigned int *baudp);
45 static void cp2101_set_termios(struct tty_struct *, struct usb_serial_port *,
46 							struct ktermios*);
47 static int cp2101_tiocmget(struct tty_struct *, struct file *);
48 static int cp2101_tiocmset(struct tty_struct *, struct file *,
49 		unsigned int, unsigned int);
50 static int cp2101_tiocmset_port(struct usb_serial_port *port, struct file *,
51 		unsigned int, unsigned int);
52 static void cp2101_break_ctl(struct tty_struct *, int);
53 static int cp2101_startup(struct usb_serial *);
54 static void cp2101_shutdown(struct usb_serial *);
55 
56 static int debug;
57 
58 static struct usb_device_id id_table [] = {
59 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
60 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
61 	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
62 	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
63 	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
64 	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
65 	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
66 	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
67 	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
68 	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
69 	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
70 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
71 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
72 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
73 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
74 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
75 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
76 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
77 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
78 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
79 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
80 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
81 	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
82 	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
83 	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
84 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
85 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
86 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
87 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
88 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
89 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
90 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demostration module */
91 	{ USB_DEVICE(0x10c4, 0x8293) }, /* Telegesys ETRX2USB */
92 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
93 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
94 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
95 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
96 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
97 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
98 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
99 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
100 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
101 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
102 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
103 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
104 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
105 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
106 	{ } /* Terminating Entry */
107 };
108 
109 MODULE_DEVICE_TABLE(usb, id_table);
110 
111 static struct usb_driver cp2101_driver = {
112 	.name		= "cp2101",
113 	.probe		= usb_serial_probe,
114 	.disconnect	= usb_serial_disconnect,
115 	.id_table	= id_table,
116 	.no_dynamic_id	= 	1,
117 };
118 
119 static struct usb_serial_driver cp2101_device = {
120 	.driver = {
121 		.owner =	THIS_MODULE,
122 		.name = 	"cp2101",
123 	},
124 	.usb_driver		= &cp2101_driver,
125 	.id_table		= id_table,
126 	.num_ports		= 1,
127 	.open			= cp2101_open,
128 	.close			= cp2101_close,
129 	.break_ctl		= cp2101_break_ctl,
130 	.set_termios		= cp2101_set_termios,
131 	.tiocmget 		= cp2101_tiocmget,
132 	.tiocmset		= cp2101_tiocmset,
133 	.attach			= cp2101_startup,
134 	.shutdown		= cp2101_shutdown,
135 };
136 
137 /* Config request types */
138 #define REQTYPE_HOST_TO_DEVICE	0x41
139 #define REQTYPE_DEVICE_TO_HOST	0xc1
140 
141 /* Config SET requests. To GET, add 1 to the request number */
142 #define CP2101_UART 		0x00	/* Enable / Disable */
143 #define CP2101_BAUDRATE		0x01	/* (BAUD_RATE_GEN_FREQ / baudrate) */
144 #define CP2101_BITS		0x03	/* 0x(0)(databits)(parity)(stopbits) */
145 #define CP2101_BREAK		0x05	/* On / Off */
146 #define CP2101_CONTROL		0x07	/* Flow control line states */
147 #define CP2101_MODEMCTL		0x13	/* Modem controls */
148 #define CP2101_CONFIG_6		0x19	/* 6 bytes of config data ??? */
149 
150 /* CP2101_UART */
151 #define UART_ENABLE		0x0001
152 #define UART_DISABLE		0x0000
153 
154 /* CP2101_BAUDRATE */
155 #define BAUD_RATE_GEN_FREQ	0x384000
156 
157 /* CP2101_BITS */
158 #define BITS_DATA_MASK		0X0f00
159 #define BITS_DATA_5		0X0500
160 #define BITS_DATA_6		0X0600
161 #define BITS_DATA_7		0X0700
162 #define BITS_DATA_8		0X0800
163 #define BITS_DATA_9		0X0900
164 
165 #define BITS_PARITY_MASK	0x00f0
166 #define BITS_PARITY_NONE	0x0000
167 #define BITS_PARITY_ODD		0x0010
168 #define BITS_PARITY_EVEN	0x0020
169 #define BITS_PARITY_MARK	0x0030
170 #define BITS_PARITY_SPACE	0x0040
171 
172 #define BITS_STOP_MASK		0x000f
173 #define BITS_STOP_1		0x0000
174 #define BITS_STOP_1_5		0x0001
175 #define BITS_STOP_2		0x0002
176 
177 /* CP2101_BREAK */
178 #define BREAK_ON		0x0000
179 #define BREAK_OFF		0x0001
180 
181 /* CP2101_CONTROL */
182 #define CONTROL_DTR		0x0001
183 #define CONTROL_RTS		0x0002
184 #define CONTROL_CTS		0x0010
185 #define CONTROL_DSR		0x0020
186 #define CONTROL_RING		0x0040
187 #define CONTROL_DCD		0x0080
188 #define CONTROL_WRITE_DTR	0x0100
189 #define CONTROL_WRITE_RTS	0x0200
190 
191 /*
192  * cp2101_get_config
193  * Reads from the CP2101 configuration registers
194  * 'size' is specified in bytes.
195  * 'data' is a pointer to a pre-allocated array of integers large
196  * enough to hold 'size' bytes (with 4 bytes to each integer)
197  */
198 static int cp2101_get_config(struct usb_serial_port *port, u8 request,
199 		unsigned int *data, int size)
200 {
201 	struct usb_serial *serial = port->serial;
202 	__le32 *buf;
203 	int result, i, length;
204 
205 	/* Number of integers required to contain the array */
206 	length = (((size - 1) | 3) + 1)/4;
207 
208 	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
209 	if (!buf) {
210 		dev_err(&port->dev, "%s - out of memory.\n", __func__);
211 		return -ENOMEM;
212 	}
213 
214 	/* For get requests, the request number must be incremented */
215 	request++;
216 
217 	/* Issue the request, attempting to read 'size' bytes */
218 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
219 				request, REQTYPE_DEVICE_TO_HOST, 0x0000,
220 				0, buf, size, 300);
221 
222 	/* Convert data into an array of integers */
223 	for (i = 0; i < length; i++)
224 		data[i] = le32_to_cpu(buf[i]);
225 
226 	kfree(buf);
227 
228 	if (result != size) {
229 		dbg("%s - Unable to send config request, "
230 				"request=0x%x size=%d result=%d\n",
231 				__func__, request, size, result);
232 		return -EPROTO;
233 	}
234 
235 	return 0;
236 }
237 
238 /*
239  * cp2101_set_config
240  * Writes to the CP2101 configuration registers
241  * Values less than 16 bits wide are sent directly
242  * 'size' is specified in bytes.
243  */
244 static int cp2101_set_config(struct usb_serial_port *port, u8 request,
245 		unsigned int *data, int size)
246 {
247 	struct usb_serial *serial = port->serial;
248 	__le32 *buf;
249 	int result, i, length;
250 
251 	/* Number of integers required to contain the array */
252 	length = (((size - 1) | 3) + 1)/4;
253 
254 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
255 	if (!buf) {
256 		dev_err(&port->dev, "%s - out of memory.\n",
257 				__func__);
258 		return -ENOMEM;
259 	}
260 
261 	/* Array of integers into bytes */
262 	for (i = 0; i < length; i++)
263 		buf[i] = cpu_to_le32(data[i]);
264 
265 	if (size > 2) {
266 		result = usb_control_msg(serial->dev,
267 				usb_sndctrlpipe(serial->dev, 0),
268 				request, REQTYPE_HOST_TO_DEVICE, 0x0000,
269 				0, buf, size, 300);
270 	} else {
271 		result = usb_control_msg(serial->dev,
272 				usb_sndctrlpipe(serial->dev, 0),
273 				request, REQTYPE_HOST_TO_DEVICE, data[0],
274 				0, NULL, 0, 300);
275 	}
276 
277 	kfree(buf);
278 
279 	if ((size > 2 && result != size) || result < 0) {
280 		dbg("%s - Unable to send request, "
281 				"request=0x%x size=%d result=%d\n",
282 				__func__, request, size, result);
283 		return -EPROTO;
284 	}
285 
286 	/* Single data value */
287 	result = usb_control_msg(serial->dev,
288 			usb_sndctrlpipe(serial->dev, 0),
289 			request, REQTYPE_HOST_TO_DEVICE, data[0],
290 			0, NULL, 0, 300);
291 	return 0;
292 }
293 
294 /*
295  * cp2101_set_config_single
296  * Convenience function for calling cp2101_set_config on single data values
297  * without requiring an integer pointer
298  */
299 static inline int cp2101_set_config_single(struct usb_serial_port *port,
300 		u8 request, unsigned int data)
301 {
302 	return cp2101_set_config(port, request, &data, 2);
303 }
304 
305 /*
306  * cp2101_quantise_baudrate
307  * Quantises the baud rate as per AN205 Table 1
308  */
309 static unsigned int cp2101_quantise_baudrate(unsigned int baud) {
310 	if      (baud <= 56)       baud = 0;
311 	else if (baud <= 300)      baud = 300;
312 	else if (baud <= 600)      baud = 600;
313 	else if (baud <= 1200)     baud = 1200;
314 	else if (baud <= 1800)     baud = 1800;
315 	else if (baud <= 2400)     baud = 2400;
316 	else if (baud <= 4000)     baud = 4000;
317 	else if (baud <= 4803)     baud = 4800;
318 	else if (baud <= 7207)     baud = 7200;
319 	else if (baud <= 9612)     baud = 9600;
320 	else if (baud <= 14428)    baud = 14400;
321 	else if (baud <= 16062)    baud = 16000;
322 	else if (baud <= 19250)    baud = 19200;
323 	else if (baud <= 28912)    baud = 28800;
324 	else if (baud <= 38601)    baud = 38400;
325 	else if (baud <= 51558)    baud = 51200;
326 	else if (baud <= 56280)    baud = 56000;
327 	else if (baud <= 58053)    baud = 57600;
328 	else if (baud <= 64111)    baud = 64000;
329 	else if (baud <= 77608)    baud = 76800;
330 	else if (baud <= 117028)   baud = 115200;
331 	else if (baud <= 129347)   baud = 128000;
332 	else if (baud <= 156868)   baud = 153600;
333 	else if (baud <= 237832)   baud = 230400;
334 	else if (baud <= 254234)   baud = 250000;
335 	else if (baud <= 273066)   baud = 256000;
336 	else if (baud <= 491520)   baud = 460800;
337 	else if (baud <= 567138)   baud = 500000;
338 	else if (baud <= 670254)   baud = 576000;
339 	else if (baud <= 1053257)  baud = 921600;
340 	else if (baud <= 1474560)  baud = 1228800;
341 	else if (baud <= 2457600)  baud = 1843200;
342 	else                       baud = 3686400;
343 	return baud;
344 }
345 
346 static int cp2101_open(struct tty_struct *tty, struct usb_serial_port *port,
347 				struct file *filp)
348 {
349 	struct usb_serial *serial = port->serial;
350 	int result;
351 
352 	dbg("%s - port %d", __func__, port->number);
353 
354 	if (cp2101_set_config_single(port, CP2101_UART, UART_ENABLE)) {
355 		dev_err(&port->dev, "%s - Unable to enable UART\n",
356 				__func__);
357 		return -EPROTO;
358 	}
359 
360 	/* Start reading from the device */
361 	usb_fill_bulk_urb(port->read_urb, serial->dev,
362 			usb_rcvbulkpipe(serial->dev,
363 			port->bulk_in_endpointAddress),
364 			port->read_urb->transfer_buffer,
365 			port->read_urb->transfer_buffer_length,
366 			serial->type->read_bulk_callback,
367 			port);
368 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
369 	if (result) {
370 		dev_err(&port->dev, "%s - failed resubmitting read urb, "
371 				"error %d\n", __func__, result);
372 		return result;
373 	}
374 
375 	/* Configure the termios structure */
376 	cp2101_get_termios(tty, port);
377 
378 	/* Set the DTR and RTS pins low */
379 	cp2101_tiocmset_port(tty ? (struct usb_serial_port *) tty->driver_data
380 			: port,
381 		NULL, TIOCM_DTR | TIOCM_RTS, 0);
382 
383 	return 0;
384 }
385 
386 static void cp2101_cleanup(struct usb_serial_port *port)
387 {
388 	struct usb_serial *serial = port->serial;
389 
390 	dbg("%s - port %d", __func__, port->number);
391 
392 	if (serial->dev) {
393 		/* shutdown any bulk reads that might be going on */
394 		if (serial->num_bulk_out)
395 			usb_kill_urb(port->write_urb);
396 		if (serial->num_bulk_in)
397 			usb_kill_urb(port->read_urb);
398 	}
399 }
400 
401 static void cp2101_close(struct tty_struct *tty, struct usb_serial_port *port,
402 					struct file *filp)
403 {
404 	dbg("%s - port %d", __func__, port->number);
405 
406 	/* shutdown our urbs */
407 	dbg("%s - shutting down urbs", __func__);
408 	usb_kill_urb(port->write_urb);
409 	usb_kill_urb(port->read_urb);
410 
411 	mutex_lock(&port->serial->disc_mutex);
412 	if (!port->serial->disconnected)
413 		cp2101_set_config_single(port, CP2101_UART, UART_DISABLE);
414 	mutex_unlock(&port->serial->disc_mutex);
415 }
416 
417 /*
418  * cp2101_get_termios
419  * Reads the baud rate, data bits, parity, stop bits and flow control mode
420  * from the device, corrects any unsupported values, and configures the
421  * termios structure to reflect the state of the device
422  */
423 static void cp2101_get_termios(struct tty_struct *tty,
424 	struct usb_serial_port *port)
425 {
426 	unsigned int baud;
427 
428 	if (tty) {
429 		cp2101_get_termios_port(tty->driver_data,
430 			&tty->termios->c_cflag, &baud);
431 		tty_encode_baud_rate(tty, baud, baud);
432 	}
433 
434 	else {
435 		unsigned int cflag;
436 		cflag = 0;
437 		cp2101_get_termios_port(port, &cflag, &baud);
438 	}
439 }
440 
441 /*
442  * cp2101_get_termios_port
443  * This is the heart of cp2101_get_termios which always uses a &usb_serial_port.
444  */
445 static void cp2101_get_termios_port(struct usb_serial_port *port,
446 	unsigned int *cflagp, unsigned int *baudp)
447 {
448 	unsigned int cflag, modem_ctl[4];
449 	unsigned int baud;
450 	unsigned int bits;
451 
452 	dbg("%s - port %d", __func__, port->number);
453 
454 	cp2101_get_config(port, CP2101_BAUDRATE, &baud, 2);
455 	/* Convert to baudrate */
456 	if (baud)
457 		baud = cp2101_quantise_baudrate((BAUD_RATE_GEN_FREQ + baud/2)/ baud);
458 
459 	dbg("%s - baud rate = %d", __func__, baud);
460 	*baudp = baud;
461 
462 	cflag = *cflagp;
463 
464 	cp2101_get_config(port, CP2101_BITS, &bits, 2);
465 	cflag &= ~CSIZE;
466 	switch (bits & BITS_DATA_MASK) {
467 	case BITS_DATA_5:
468 		dbg("%s - data bits = 5", __func__);
469 		cflag |= CS5;
470 		break;
471 	case BITS_DATA_6:
472 		dbg("%s - data bits = 6", __func__);
473 		cflag |= CS6;
474 		break;
475 	case BITS_DATA_7:
476 		dbg("%s - data bits = 7", __func__);
477 		cflag |= CS7;
478 		break;
479 	case BITS_DATA_8:
480 		dbg("%s - data bits = 8", __func__);
481 		cflag |= CS8;
482 		break;
483 	case BITS_DATA_9:
484 		dbg("%s - data bits = 9 (not supported, using 8 data bits)",
485 								__func__);
486 		cflag |= CS8;
487 		bits &= ~BITS_DATA_MASK;
488 		bits |= BITS_DATA_8;
489 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
490 		break;
491 	default:
492 		dbg("%s - Unknown number of data bits, using 8", __func__);
493 		cflag |= CS8;
494 		bits &= ~BITS_DATA_MASK;
495 		bits |= BITS_DATA_8;
496 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
497 		break;
498 	}
499 
500 	switch (bits & BITS_PARITY_MASK) {
501 	case BITS_PARITY_NONE:
502 		dbg("%s - parity = NONE", __func__);
503 		cflag &= ~PARENB;
504 		break;
505 	case BITS_PARITY_ODD:
506 		dbg("%s - parity = ODD", __func__);
507 		cflag |= (PARENB|PARODD);
508 		break;
509 	case BITS_PARITY_EVEN:
510 		dbg("%s - parity = EVEN", __func__);
511 		cflag &= ~PARODD;
512 		cflag |= PARENB;
513 		break;
514 	case BITS_PARITY_MARK:
515 		dbg("%s - parity = MARK (not supported, disabling parity)",
516 				__func__);
517 		cflag &= ~PARENB;
518 		bits &= ~BITS_PARITY_MASK;
519 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
520 		break;
521 	case BITS_PARITY_SPACE:
522 		dbg("%s - parity = SPACE (not supported, disabling parity)",
523 				__func__);
524 		cflag &= ~PARENB;
525 		bits &= ~BITS_PARITY_MASK;
526 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
527 		break;
528 	default:
529 		dbg("%s - Unknown parity mode, disabling parity", __func__);
530 		cflag &= ~PARENB;
531 		bits &= ~BITS_PARITY_MASK;
532 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
533 		break;
534 	}
535 
536 	cflag &= ~CSTOPB;
537 	switch (bits & BITS_STOP_MASK) {
538 	case BITS_STOP_1:
539 		dbg("%s - stop bits = 1", __func__);
540 		break;
541 	case BITS_STOP_1_5:
542 		dbg("%s - stop bits = 1.5 (not supported, using 1 stop bit)",
543 								__func__);
544 		bits &= ~BITS_STOP_MASK;
545 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
546 		break;
547 	case BITS_STOP_2:
548 		dbg("%s - stop bits = 2", __func__);
549 		cflag |= CSTOPB;
550 		break;
551 	default:
552 		dbg("%s - Unknown number of stop bits, using 1 stop bit",
553 								__func__);
554 		bits &= ~BITS_STOP_MASK;
555 		cp2101_set_config(port, CP2101_BITS, &bits, 2);
556 		break;
557 	}
558 
559 	cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16);
560 	if (modem_ctl[0] & 0x0008) {
561 		dbg("%s - flow control = CRTSCTS", __func__);
562 		cflag |= CRTSCTS;
563 	} else {
564 		dbg("%s - flow control = NONE", __func__);
565 		cflag &= ~CRTSCTS;
566 	}
567 
568 	*cflagp = cflag;
569 }
570 
571 static void cp2101_set_termios(struct tty_struct *tty,
572 		struct usb_serial_port *port, struct ktermios *old_termios)
573 {
574 	unsigned int cflag, old_cflag;
575 	unsigned int baud = 0, bits;
576 	unsigned int modem_ctl[4];
577 
578 	dbg("%s - port %d", __func__, port->number);
579 
580 	if (!tty)
581 		return;
582 
583 	tty->termios->c_cflag &= ~CMSPAR;
584 	cflag = tty->termios->c_cflag;
585 	old_cflag = old_termios->c_cflag;
586 	baud = cp2101_quantise_baudrate(tty_get_baud_rate(tty));
587 
588 	/* If the baud rate is to be updated*/
589 	if (baud != tty_termios_baud_rate(old_termios) && baud != 0) {
590 		dbg("%s - Setting baud rate to %d baud", __func__,
591 				baud);
592 		if (cp2101_set_config_single(port, CP2101_BAUDRATE,
593 					((BAUD_RATE_GEN_FREQ + baud/2) / baud))) {
594 			dbg("Baud rate requested not supported by device\n");
595 			baud = tty_termios_baud_rate(old_termios);
596 		}
597 	}
598 	/* Report back the resulting baud rate */
599 	tty_encode_baud_rate(tty, baud, baud);
600 
601 	/* If the number of data bits is to be updated */
602 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
603 		cp2101_get_config(port, CP2101_BITS, &bits, 2);
604 		bits &= ~BITS_DATA_MASK;
605 		switch (cflag & CSIZE) {
606 		case CS5:
607 			bits |= BITS_DATA_5;
608 			dbg("%s - data bits = 5", __func__);
609 			break;
610 		case CS6:
611 			bits |= BITS_DATA_6;
612 			dbg("%s - data bits = 6", __func__);
613 			break;
614 		case CS7:
615 			bits |= BITS_DATA_7;
616 			dbg("%s - data bits = 7", __func__);
617 			break;
618 		case CS8:
619 			bits |= BITS_DATA_8;
620 			dbg("%s - data bits = 8", __func__);
621 			break;
622 		/*case CS9:
623 			bits |= BITS_DATA_9;
624 			dbg("%s - data bits = 9", __func__);
625 			break;*/
626 		default:
627 			dbg("cp2101 driver does not "
628 					"support the number of bits requested,"
629 					" using 8 bit mode\n");
630 				bits |= BITS_DATA_8;
631 				break;
632 		}
633 		if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
634 			dbg("Number of data bits requested "
635 					"not supported by device\n");
636 	}
637 
638 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) {
639 		cp2101_get_config(port, CP2101_BITS, &bits, 2);
640 		bits &= ~BITS_PARITY_MASK;
641 		if (cflag & PARENB) {
642 			if (cflag & PARODD) {
643 				bits |= BITS_PARITY_ODD;
644 				dbg("%s - parity = ODD", __func__);
645 			} else {
646 				bits |= BITS_PARITY_EVEN;
647 				dbg("%s - parity = EVEN", __func__);
648 			}
649 		}
650 		if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
651 			dbg("Parity mode not supported "
652 					"by device\n");
653 	}
654 
655 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
656 		cp2101_get_config(port, CP2101_BITS, &bits, 2);
657 		bits &= ~BITS_STOP_MASK;
658 		if (cflag & CSTOPB) {
659 			bits |= BITS_STOP_2;
660 			dbg("%s - stop bits = 2", __func__);
661 		} else {
662 			bits |= BITS_STOP_1;
663 			dbg("%s - stop bits = 1", __func__);
664 		}
665 		if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
666 			dbg("Number of stop bits requested "
667 					"not supported by device\n");
668 	}
669 
670 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
671 		cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16);
672 		dbg("%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
673 				__func__, modem_ctl[0], modem_ctl[1],
674 				modem_ctl[2], modem_ctl[3]);
675 
676 		if (cflag & CRTSCTS) {
677 			modem_ctl[0] &= ~0x7B;
678 			modem_ctl[0] |= 0x09;
679 			modem_ctl[1] = 0x80;
680 			dbg("%s - flow control = CRTSCTS", __func__);
681 		} else {
682 			modem_ctl[0] &= ~0x7B;
683 			modem_ctl[0] |= 0x01;
684 			modem_ctl[1] |= 0x40;
685 			dbg("%s - flow control = NONE", __func__);
686 		}
687 
688 		dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
689 				__func__, modem_ctl[0], modem_ctl[1],
690 				modem_ctl[2], modem_ctl[3]);
691 		cp2101_set_config(port, CP2101_MODEMCTL, modem_ctl, 16);
692 	}
693 
694 }
695 
696 static int cp2101_tiocmset (struct tty_struct *tty, struct file *file,
697 		unsigned int set, unsigned int clear)
698 {
699 	struct usb_serial_port *port = tty->driver_data;
700 	return cp2101_tiocmset_port(port, file, set, clear);
701 }
702 
703 static int cp2101_tiocmset_port(struct usb_serial_port *port, struct file *file,
704 		unsigned int set, unsigned int clear)
705 {
706 	unsigned int control = 0;
707 
708 	dbg("%s - port %d", __func__, port->number);
709 
710 	if (set & TIOCM_RTS) {
711 		control |= CONTROL_RTS;
712 		control |= CONTROL_WRITE_RTS;
713 	}
714 	if (set & TIOCM_DTR) {
715 		control |= CONTROL_DTR;
716 		control |= CONTROL_WRITE_DTR;
717 	}
718 	if (clear & TIOCM_RTS) {
719 		control &= ~CONTROL_RTS;
720 		control |= CONTROL_WRITE_RTS;
721 	}
722 	if (clear & TIOCM_DTR) {
723 		control &= ~CONTROL_DTR;
724 		control |= CONTROL_WRITE_DTR;
725 	}
726 
727 	dbg("%s - control = 0x%.4x", __func__, control);
728 
729 	return cp2101_set_config(port, CP2101_CONTROL, &control, 2);
730 }
731 
732 static int cp2101_tiocmget (struct tty_struct *tty, struct file *file)
733 {
734 	struct usb_serial_port *port = tty->driver_data;
735 	unsigned int control;
736 	int result;
737 
738 	dbg("%s - port %d", __func__, port->number);
739 
740 	cp2101_get_config(port, CP2101_CONTROL, &control, 1);
741 
742 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
743 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
744 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
745 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
746 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
747 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
748 
749 	dbg("%s - control = 0x%.2x", __func__, control);
750 
751 	return result;
752 }
753 
754 static void cp2101_break_ctl (struct tty_struct *tty, int break_state)
755 {
756 	struct usb_serial_port *port = tty->driver_data;
757 	unsigned int state;
758 
759 	dbg("%s - port %d", __func__, port->number);
760 	if (break_state == 0)
761 		state = BREAK_OFF;
762 	else
763 		state = BREAK_ON;
764 	dbg("%s - turning break %s", __func__,
765 			state == BREAK_OFF ? "off" : "on");
766 	cp2101_set_config(port, CP2101_BREAK, &state, 2);
767 }
768 
769 static int cp2101_startup(struct usb_serial *serial)
770 {
771 	/* CP2101 buffers behave strangely unless device is reset */
772 	usb_reset_device(serial->dev);
773 	return 0;
774 }
775 
776 static void cp2101_shutdown(struct usb_serial *serial)
777 {
778 	int i;
779 
780 	dbg("%s", __func__);
781 
782 	/* Stop reads and writes on all ports */
783 	for (i = 0; i < serial->num_ports; ++i)
784 		cp2101_cleanup(serial->port[i]);
785 }
786 
787 static int __init cp2101_init(void)
788 {
789 	int retval;
790 
791 	retval = usb_serial_register(&cp2101_device);
792 	if (retval)
793 		return retval; /* Failed to register */
794 
795 	retval = usb_register(&cp2101_driver);
796 	if (retval) {
797 		/* Failed to register */
798 		usb_serial_deregister(&cp2101_device);
799 		return retval;
800 	}
801 
802 	/* Success */
803 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
804 	       DRIVER_DESC "\n");
805 	return 0;
806 }
807 
808 static void __exit cp2101_exit(void)
809 {
810 	usb_deregister(&cp2101_driver);
811 	usb_serial_deregister(&cp2101_device);
812 }
813 
814 module_init(cp2101_init);
815 module_exit(cp2101_exit);
816 
817 MODULE_DESCRIPTION(DRIVER_DESC);
818 MODULE_VERSION(DRIVER_VERSION);
819 MODULE_LICENSE("GPL");
820 
821 module_param(debug, bool, S_IRUGO | S_IWUSR);
822 MODULE_PARM_DESC(debug, "Enable verbose debugging messages");
823