xref: /linux/drivers/usb/serial/cp210x.c (revision 11e4afb49b7fa1fc8e1ffd850c1806dd86a08204)
1 /*
2  * Silicon Laboratories CP210x 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 "v0.09"
31 #define DRIVER_DESC "Silicon Labs CP210x RS232 serial adaptor driver"
32 
33 /*
34  * Function Prototypes
35  */
36 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *);
37 static void cp210x_close(struct usb_serial_port *);
38 static void cp210x_get_termios(struct tty_struct *,
39 	struct usb_serial_port *port);
40 static void cp210x_get_termios_port(struct usb_serial_port *port,
41 	unsigned int *cflagp, unsigned int *baudp);
42 static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
43 							struct ktermios*);
44 static int cp210x_tiocmget(struct tty_struct *, struct file *);
45 static int cp210x_tiocmset(struct tty_struct *, struct file *,
46 		unsigned int, unsigned int);
47 static int cp210x_tiocmset_port(struct usb_serial_port *port, struct file *,
48 		unsigned int, unsigned int);
49 static void cp210x_break_ctl(struct tty_struct *, int);
50 static int cp210x_startup(struct usb_serial *);
51 static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
52 static int cp210x_carrier_raised(struct usb_serial_port *p);
53 
54 static int debug;
55 
56 static const struct usb_device_id id_table[] = {
57 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
58 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
59 	{ USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
60 	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
61 	{ USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
62 	{ USB_DEVICE(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
63 	{ USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
64 	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
65 	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
66 	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
67 	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
68 	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
69 	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
70 	{ USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
71 	{ USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
72 	{ USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
73 	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
74 	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
75 	{ USB_DEVICE(0x10C4, 0x8044) }, /* Cygnal Debug Adapter */
76 	{ USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
77 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
78 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
79 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
80 	{ USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
81 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
82 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
83 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
84 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
85 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
86 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
87 	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
88 	{ USB_DEVICE(0x10C4, 0x8149) }, /* West Mountain Radio Computerized Battery Analyzer */
89 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
90 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
91 	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
92 	{ USB_DEVICE(0x10C4, 0x818B) }, /* AVIT Research USB to TTL */
93 	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
94 	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
95 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
96 	{ USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
97 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
98 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
99 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
100 	{ USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
101 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
102 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
103 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
104 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demostration module */
105 	{ USB_DEVICE(0x10C4, 0x8293) }, /* Telegesys ETRX2USB */
106 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
107 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
108 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
109 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
110 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
111 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
112 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
113 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
114 	{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
115 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
116 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
117 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
118 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
119 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
120 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
121 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
122 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
123 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
124 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
125 	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
126 	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
127 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
128 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
129 	{ } /* Terminating Entry */
130 };
131 
132 MODULE_DEVICE_TABLE(usb, id_table);
133 
134 static struct usb_driver cp210x_driver = {
135 	.name		= "cp210x",
136 	.probe		= usb_serial_probe,
137 	.disconnect	= usb_serial_disconnect,
138 	.id_table	= id_table,
139 	.no_dynamic_id	= 	1,
140 };
141 
142 static struct usb_serial_driver cp210x_device = {
143 	.driver = {
144 		.owner =	THIS_MODULE,
145 		.name = 	"cp210x",
146 	},
147 	.usb_driver		= &cp210x_driver,
148 	.id_table		= id_table,
149 	.num_ports		= 1,
150 	.bulk_in_size		= 256,
151 	.bulk_out_size		= 256,
152 	.open			= cp210x_open,
153 	.close			= cp210x_close,
154 	.break_ctl		= cp210x_break_ctl,
155 	.set_termios		= cp210x_set_termios,
156 	.tiocmget 		= cp210x_tiocmget,
157 	.tiocmset		= cp210x_tiocmset,
158 	.attach			= cp210x_startup,
159 	.dtr_rts		= cp210x_dtr_rts,
160 	.carrier_raised		= cp210x_carrier_raised
161 };
162 
163 /* Config request types */
164 #define REQTYPE_HOST_TO_DEVICE	0x41
165 #define REQTYPE_DEVICE_TO_HOST	0xc1
166 
167 /* Config request codes */
168 #define CP210X_IFC_ENABLE	0x00
169 #define CP210X_SET_BAUDDIV	0x01
170 #define CP210X_GET_BAUDDIV	0x02
171 #define CP210X_SET_LINE_CTL	0x03
172 #define CP210X_GET_LINE_CTL	0x04
173 #define CP210X_SET_BREAK	0x05
174 #define CP210X_IMM_CHAR		0x06
175 #define CP210X_SET_MHS		0x07
176 #define CP210X_GET_MDMSTS	0x08
177 #define CP210X_SET_XON		0x09
178 #define CP210X_SET_XOFF		0x0A
179 #define CP210X_SET_EVENTMASK	0x0B
180 #define CP210X_GET_EVENTMASK	0x0C
181 #define CP210X_SET_CHAR		0x0D
182 #define CP210X_GET_CHARS	0x0E
183 #define CP210X_GET_PROPS	0x0F
184 #define CP210X_GET_COMM_STATUS	0x10
185 #define CP210X_RESET		0x11
186 #define CP210X_PURGE		0x12
187 #define CP210X_SET_FLOW		0x13
188 #define CP210X_GET_FLOW		0x14
189 #define CP210X_EMBED_EVENTS	0x15
190 #define CP210X_GET_EVENTSTATE	0x16
191 #define CP210X_SET_CHARS	0x19
192 
193 /* CP210X_IFC_ENABLE */
194 #define UART_ENABLE		0x0001
195 #define UART_DISABLE		0x0000
196 
197 /* CP210X_(SET|GET)_BAUDDIV */
198 #define BAUD_RATE_GEN_FREQ	0x384000
199 
200 /* CP210X_(SET|GET)_LINE_CTL */
201 #define BITS_DATA_MASK		0X0f00
202 #define BITS_DATA_5		0X0500
203 #define BITS_DATA_6		0X0600
204 #define BITS_DATA_7		0X0700
205 #define BITS_DATA_8		0X0800
206 #define BITS_DATA_9		0X0900
207 
208 #define BITS_PARITY_MASK	0x00f0
209 #define BITS_PARITY_NONE	0x0000
210 #define BITS_PARITY_ODD		0x0010
211 #define BITS_PARITY_EVEN	0x0020
212 #define BITS_PARITY_MARK	0x0030
213 #define BITS_PARITY_SPACE	0x0040
214 
215 #define BITS_STOP_MASK		0x000f
216 #define BITS_STOP_1		0x0000
217 #define BITS_STOP_1_5		0x0001
218 #define BITS_STOP_2		0x0002
219 
220 /* CP210X_SET_BREAK */
221 #define BREAK_ON		0x0000
222 #define BREAK_OFF		0x0001
223 
224 /* CP210X_(SET_MHS|GET_MDMSTS) */
225 #define CONTROL_DTR		0x0001
226 #define CONTROL_RTS		0x0002
227 #define CONTROL_CTS		0x0010
228 #define CONTROL_DSR		0x0020
229 #define CONTROL_RING		0x0040
230 #define CONTROL_DCD		0x0080
231 #define CONTROL_WRITE_DTR	0x0100
232 #define CONTROL_WRITE_RTS	0x0200
233 
234 /*
235  * cp210x_get_config
236  * Reads from the CP210x configuration registers
237  * 'size' is specified in bytes.
238  * 'data' is a pointer to a pre-allocated array of integers large
239  * enough to hold 'size' bytes (with 4 bytes to each integer)
240  */
241 static int cp210x_get_config(struct usb_serial_port *port, u8 request,
242 		unsigned int *data, int size)
243 {
244 	struct usb_serial *serial = port->serial;
245 	__le32 *buf;
246 	int result, i, length;
247 
248 	/* Number of integers required to contain the array */
249 	length = (((size - 1) | 3) + 1)/4;
250 
251 	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
252 	if (!buf) {
253 		dev_err(&port->dev, "%s - out of memory.\n", __func__);
254 		return -ENOMEM;
255 	}
256 
257 	/* Issue the request, attempting to read 'size' bytes */
258 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
259 				request, REQTYPE_DEVICE_TO_HOST, 0x0000,
260 				0, buf, size, 300);
261 
262 	/* Convert data into an array of integers */
263 	for (i = 0; i < length; i++)
264 		data[i] = le32_to_cpu(buf[i]);
265 
266 	kfree(buf);
267 
268 	if (result != size) {
269 		dbg("%s - Unable to send config request, "
270 				"request=0x%x size=%d result=%d\n",
271 				__func__, request, size, result);
272 		return -EPROTO;
273 	}
274 
275 	return 0;
276 }
277 
278 /*
279  * cp210x_set_config
280  * Writes to the CP210x configuration registers
281  * Values less than 16 bits wide are sent directly
282  * 'size' is specified in bytes.
283  */
284 static int cp210x_set_config(struct usb_serial_port *port, u8 request,
285 		unsigned int *data, int size)
286 {
287 	struct usb_serial *serial = port->serial;
288 	__le32 *buf;
289 	int result, i, length;
290 
291 	/* Number of integers required to contain the array */
292 	length = (((size - 1) | 3) + 1)/4;
293 
294 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
295 	if (!buf) {
296 		dev_err(&port->dev, "%s - out of memory.\n",
297 				__func__);
298 		return -ENOMEM;
299 	}
300 
301 	/* Array of integers into bytes */
302 	for (i = 0; i < length; i++)
303 		buf[i] = cpu_to_le32(data[i]);
304 
305 	if (size > 2) {
306 		result = usb_control_msg(serial->dev,
307 				usb_sndctrlpipe(serial->dev, 0),
308 				request, REQTYPE_HOST_TO_DEVICE, 0x0000,
309 				0, buf, size, 300);
310 	} else {
311 		result = usb_control_msg(serial->dev,
312 				usb_sndctrlpipe(serial->dev, 0),
313 				request, REQTYPE_HOST_TO_DEVICE, data[0],
314 				0, NULL, 0, 300);
315 	}
316 
317 	kfree(buf);
318 
319 	if ((size > 2 && result != size) || result < 0) {
320 		dbg("%s - Unable to send request, "
321 				"request=0x%x size=%d result=%d\n",
322 				__func__, request, size, result);
323 		return -EPROTO;
324 	}
325 
326 	return 0;
327 }
328 
329 /*
330  * cp210x_set_config_single
331  * Convenience function for calling cp210x_set_config on single data values
332  * without requiring an integer pointer
333  */
334 static inline int cp210x_set_config_single(struct usb_serial_port *port,
335 		u8 request, unsigned int data)
336 {
337 	return cp210x_set_config(port, request, &data, 2);
338 }
339 
340 /*
341  * cp210x_quantise_baudrate
342  * Quantises the baud rate as per AN205 Table 1
343  */
344 static unsigned int cp210x_quantise_baudrate(unsigned int baud) {
345 	if      (baud <= 56)       baud = 0;
346 	else if (baud <= 300)      baud = 300;
347 	else if (baud <= 600)      baud = 600;
348 	else if (baud <= 1200)     baud = 1200;
349 	else if (baud <= 1800)     baud = 1800;
350 	else if (baud <= 2400)     baud = 2400;
351 	else if (baud <= 4000)     baud = 4000;
352 	else if (baud <= 4803)     baud = 4800;
353 	else if (baud <= 7207)     baud = 7200;
354 	else if (baud <= 9612)     baud = 9600;
355 	else if (baud <= 14428)    baud = 14400;
356 	else if (baud <= 16062)    baud = 16000;
357 	else if (baud <= 19250)    baud = 19200;
358 	else if (baud <= 28912)    baud = 28800;
359 	else if (baud <= 38601)    baud = 38400;
360 	else if (baud <= 51558)    baud = 51200;
361 	else if (baud <= 56280)    baud = 56000;
362 	else if (baud <= 58053)    baud = 57600;
363 	else if (baud <= 64111)    baud = 64000;
364 	else if (baud <= 77608)    baud = 76800;
365 	else if (baud <= 117028)   baud = 115200;
366 	else if (baud <= 129347)   baud = 128000;
367 	else if (baud <= 156868)   baud = 153600;
368 	else if (baud <= 237832)   baud = 230400;
369 	else if (baud <= 254234)   baud = 250000;
370 	else if (baud <= 273066)   baud = 256000;
371 	else if (baud <= 491520)   baud = 460800;
372 	else if (baud <= 567138)   baud = 500000;
373 	else if (baud <= 670254)   baud = 576000;
374 	else if (baud <= 1053257)  baud = 921600;
375 	else if (baud <= 1474560)  baud = 1228800;
376 	else if (baud <= 2457600)  baud = 1843200;
377 	else                       baud = 3686400;
378 	return baud;
379 }
380 
381 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
382 {
383 	int result;
384 
385 	dbg("%s - port %d", __func__, port->number);
386 
387 	if (cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_ENABLE)) {
388 		dev_err(&port->dev, "%s - Unable to enable UART\n",
389 				__func__);
390 		return -EPROTO;
391 	}
392 
393 	result = usb_serial_generic_open(tty, port);
394 	if (result)
395 		return result;
396 
397 	/* Configure the termios structure */
398 	cp210x_get_termios(tty, port);
399 	return 0;
400 }
401 
402 static void cp210x_close(struct usb_serial_port *port)
403 {
404 	dbg("%s - port %d", __func__, port->number);
405 
406 	usb_serial_generic_close(port);
407 
408 	mutex_lock(&port->serial->disc_mutex);
409 	if (!port->serial->disconnected)
410 		cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
411 	mutex_unlock(&port->serial->disc_mutex);
412 }
413 
414 /*
415  * cp210x_get_termios
416  * Reads the baud rate, data bits, parity, stop bits and flow control mode
417  * from the device, corrects any unsupported values, and configures the
418  * termios structure to reflect the state of the device
419  */
420 static void cp210x_get_termios(struct tty_struct *tty,
421 	struct usb_serial_port *port)
422 {
423 	unsigned int baud;
424 
425 	if (tty) {
426 		cp210x_get_termios_port(tty->driver_data,
427 			&tty->termios->c_cflag, &baud);
428 		tty_encode_baud_rate(tty, baud, baud);
429 	}
430 
431 	else {
432 		unsigned int cflag;
433 		cflag = 0;
434 		cp210x_get_termios_port(port, &cflag, &baud);
435 	}
436 }
437 
438 /*
439  * cp210x_get_termios_port
440  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
441  */
442 static void cp210x_get_termios_port(struct usb_serial_port *port,
443 	unsigned int *cflagp, unsigned int *baudp)
444 {
445 	unsigned int cflag, modem_ctl[4];
446 	unsigned int baud;
447 	unsigned int bits;
448 
449 	dbg("%s - port %d", __func__, port->number);
450 
451 	cp210x_get_config(port, CP210X_GET_BAUDDIV, &baud, 2);
452 	/* Convert to baudrate */
453 	if (baud)
454 		baud = cp210x_quantise_baudrate((BAUD_RATE_GEN_FREQ + baud/2)/ baud);
455 
456 	dbg("%s - baud rate = %d", __func__, baud);
457 	*baudp = baud;
458 
459 	cflag = *cflagp;
460 
461 	cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
462 	cflag &= ~CSIZE;
463 	switch (bits & BITS_DATA_MASK) {
464 	case BITS_DATA_5:
465 		dbg("%s - data bits = 5", __func__);
466 		cflag |= CS5;
467 		break;
468 	case BITS_DATA_6:
469 		dbg("%s - data bits = 6", __func__);
470 		cflag |= CS6;
471 		break;
472 	case BITS_DATA_7:
473 		dbg("%s - data bits = 7", __func__);
474 		cflag |= CS7;
475 		break;
476 	case BITS_DATA_8:
477 		dbg("%s - data bits = 8", __func__);
478 		cflag |= CS8;
479 		break;
480 	case BITS_DATA_9:
481 		dbg("%s - data bits = 9 (not supported, using 8 data bits)",
482 								__func__);
483 		cflag |= CS8;
484 		bits &= ~BITS_DATA_MASK;
485 		bits |= BITS_DATA_8;
486 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
487 		break;
488 	default:
489 		dbg("%s - Unknown number of data bits, using 8", __func__);
490 		cflag |= CS8;
491 		bits &= ~BITS_DATA_MASK;
492 		bits |= BITS_DATA_8;
493 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
494 		break;
495 	}
496 
497 	switch (bits & BITS_PARITY_MASK) {
498 	case BITS_PARITY_NONE:
499 		dbg("%s - parity = NONE", __func__);
500 		cflag &= ~PARENB;
501 		break;
502 	case BITS_PARITY_ODD:
503 		dbg("%s - parity = ODD", __func__);
504 		cflag |= (PARENB|PARODD);
505 		break;
506 	case BITS_PARITY_EVEN:
507 		dbg("%s - parity = EVEN", __func__);
508 		cflag &= ~PARODD;
509 		cflag |= PARENB;
510 		break;
511 	case BITS_PARITY_MARK:
512 		dbg("%s - parity = MARK (not supported, disabling parity)",
513 				__func__);
514 		cflag &= ~PARENB;
515 		bits &= ~BITS_PARITY_MASK;
516 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
517 		break;
518 	case BITS_PARITY_SPACE:
519 		dbg("%s - parity = SPACE (not supported, disabling parity)",
520 				__func__);
521 		cflag &= ~PARENB;
522 		bits &= ~BITS_PARITY_MASK;
523 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
524 		break;
525 	default:
526 		dbg("%s - Unknown parity mode, disabling parity", __func__);
527 		cflag &= ~PARENB;
528 		bits &= ~BITS_PARITY_MASK;
529 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
530 		break;
531 	}
532 
533 	cflag &= ~CSTOPB;
534 	switch (bits & BITS_STOP_MASK) {
535 	case BITS_STOP_1:
536 		dbg("%s - stop bits = 1", __func__);
537 		break;
538 	case BITS_STOP_1_5:
539 		dbg("%s - stop bits = 1.5 (not supported, using 1 stop bit)",
540 								__func__);
541 		bits &= ~BITS_STOP_MASK;
542 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
543 		break;
544 	case BITS_STOP_2:
545 		dbg("%s - stop bits = 2", __func__);
546 		cflag |= CSTOPB;
547 		break;
548 	default:
549 		dbg("%s - Unknown number of stop bits, using 1 stop bit",
550 								__func__);
551 		bits &= ~BITS_STOP_MASK;
552 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
553 		break;
554 	}
555 
556 	cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
557 	if (modem_ctl[0] & 0x0008) {
558 		dbg("%s - flow control = CRTSCTS", __func__);
559 		cflag |= CRTSCTS;
560 	} else {
561 		dbg("%s - flow control = NONE", __func__);
562 		cflag &= ~CRTSCTS;
563 	}
564 
565 	*cflagp = cflag;
566 }
567 
568 static void cp210x_set_termios(struct tty_struct *tty,
569 		struct usb_serial_port *port, struct ktermios *old_termios)
570 {
571 	unsigned int cflag, old_cflag;
572 	unsigned int baud = 0, bits;
573 	unsigned int modem_ctl[4];
574 
575 	dbg("%s - port %d", __func__, port->number);
576 
577 	if (!tty)
578 		return;
579 
580 	tty->termios->c_cflag &= ~CMSPAR;
581 	cflag = tty->termios->c_cflag;
582 	old_cflag = old_termios->c_cflag;
583 	baud = cp210x_quantise_baudrate(tty_get_baud_rate(tty));
584 
585 	/* If the baud rate is to be updated*/
586 	if (baud != tty_termios_baud_rate(old_termios) && baud != 0) {
587 		dbg("%s - Setting baud rate to %d baud", __func__,
588 				baud);
589 		if (cp210x_set_config_single(port, CP210X_SET_BAUDDIV,
590 					((BAUD_RATE_GEN_FREQ + baud/2) / baud))) {
591 			dbg("Baud rate requested not supported by device");
592 			baud = tty_termios_baud_rate(old_termios);
593 		}
594 	}
595 	/* Report back the resulting baud rate */
596 	tty_encode_baud_rate(tty, baud, baud);
597 
598 	/* If the number of data bits is to be updated */
599 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
600 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
601 		bits &= ~BITS_DATA_MASK;
602 		switch (cflag & CSIZE) {
603 		case CS5:
604 			bits |= BITS_DATA_5;
605 			dbg("%s - data bits = 5", __func__);
606 			break;
607 		case CS6:
608 			bits |= BITS_DATA_6;
609 			dbg("%s - data bits = 6", __func__);
610 			break;
611 		case CS7:
612 			bits |= BITS_DATA_7;
613 			dbg("%s - data bits = 7", __func__);
614 			break;
615 		case CS8:
616 			bits |= BITS_DATA_8;
617 			dbg("%s - data bits = 8", __func__);
618 			break;
619 		/*case CS9:
620 			bits |= BITS_DATA_9;
621 			dbg("%s - data bits = 9", __func__);
622 			break;*/
623 		default:
624 			dbg("cp210x driver does not "
625 					"support the number of bits requested,"
626 					" using 8 bit mode\n");
627 				bits |= BITS_DATA_8;
628 				break;
629 		}
630 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
631 			dbg("Number of data bits requested "
632 					"not supported by device\n");
633 	}
634 
635 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) {
636 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
637 		bits &= ~BITS_PARITY_MASK;
638 		if (cflag & PARENB) {
639 			if (cflag & PARODD) {
640 				bits |= BITS_PARITY_ODD;
641 				dbg("%s - parity = ODD", __func__);
642 			} else {
643 				bits |= BITS_PARITY_EVEN;
644 				dbg("%s - parity = EVEN", __func__);
645 			}
646 		}
647 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
648 			dbg("Parity mode not supported "
649 					"by device\n");
650 	}
651 
652 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
653 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
654 		bits &= ~BITS_STOP_MASK;
655 		if (cflag & CSTOPB) {
656 			bits |= BITS_STOP_2;
657 			dbg("%s - stop bits = 2", __func__);
658 		} else {
659 			bits |= BITS_STOP_1;
660 			dbg("%s - stop bits = 1", __func__);
661 		}
662 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
663 			dbg("Number of stop bits requested "
664 					"not supported by device\n");
665 	}
666 
667 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
668 		cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
669 		dbg("%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
670 				__func__, modem_ctl[0], modem_ctl[1],
671 				modem_ctl[2], modem_ctl[3]);
672 
673 		if (cflag & CRTSCTS) {
674 			modem_ctl[0] &= ~0x7B;
675 			modem_ctl[0] |= 0x09;
676 			modem_ctl[1] = 0x80;
677 			dbg("%s - flow control = CRTSCTS", __func__);
678 		} else {
679 			modem_ctl[0] &= ~0x7B;
680 			modem_ctl[0] |= 0x01;
681 			modem_ctl[1] |= 0x40;
682 			dbg("%s - flow control = NONE", __func__);
683 		}
684 
685 		dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
686 				__func__, modem_ctl[0], modem_ctl[1],
687 				modem_ctl[2], modem_ctl[3]);
688 		cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
689 	}
690 
691 }
692 
693 static int cp210x_tiocmset (struct tty_struct *tty, struct file *file,
694 		unsigned int set, unsigned int clear)
695 {
696 	struct usb_serial_port *port = tty->driver_data;
697 	return cp210x_tiocmset_port(port, file, set, clear);
698 }
699 
700 static int cp210x_tiocmset_port(struct usb_serial_port *port, struct file *file,
701 		unsigned int set, unsigned int clear)
702 {
703 	unsigned int control = 0;
704 
705 	dbg("%s - port %d", __func__, port->number);
706 
707 	if (set & TIOCM_RTS) {
708 		control |= CONTROL_RTS;
709 		control |= CONTROL_WRITE_RTS;
710 	}
711 	if (set & TIOCM_DTR) {
712 		control |= CONTROL_DTR;
713 		control |= CONTROL_WRITE_DTR;
714 	}
715 	if (clear & TIOCM_RTS) {
716 		control &= ~CONTROL_RTS;
717 		control |= CONTROL_WRITE_RTS;
718 	}
719 	if (clear & TIOCM_DTR) {
720 		control &= ~CONTROL_DTR;
721 		control |= CONTROL_WRITE_DTR;
722 	}
723 
724 	dbg("%s - control = 0x%.4x", __func__, control);
725 
726 	return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
727 }
728 
729 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
730 {
731 	if (on)
732 		cp210x_tiocmset_port(p, NULL,  TIOCM_DTR|TIOCM_RTS, 0);
733 	else
734 		cp210x_tiocmset_port(p, NULL,  0, TIOCM_DTR|TIOCM_RTS);
735 }
736 
737 static int cp210x_tiocmget (struct tty_struct *tty, struct file *file)
738 {
739 	struct usb_serial_port *port = tty->driver_data;
740 	unsigned int control;
741 	int result;
742 
743 	dbg("%s - port %d", __func__, port->number);
744 
745 	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
746 
747 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
748 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
749 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
750 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
751 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
752 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
753 
754 	dbg("%s - control = 0x%.2x", __func__, control);
755 
756 	return result;
757 }
758 
759 static int cp210x_carrier_raised(struct usb_serial_port *p)
760 {
761 	unsigned int control;
762 	cp210x_get_config(p, CP210X_GET_MDMSTS, &control, 1);
763 	if (control & CONTROL_DCD)
764 		return 1;
765 	return 0;
766 }
767 
768 static void cp210x_break_ctl (struct tty_struct *tty, int break_state)
769 {
770 	struct usb_serial_port *port = tty->driver_data;
771 	unsigned int state;
772 
773 	dbg("%s - port %d", __func__, port->number);
774 	if (break_state == 0)
775 		state = BREAK_OFF;
776 	else
777 		state = BREAK_ON;
778 	dbg("%s - turning break %s", __func__,
779 			state == BREAK_OFF ? "off" : "on");
780 	cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
781 }
782 
783 static int cp210x_startup(struct usb_serial *serial)
784 {
785 	/* cp210x buffers behave strangely unless device is reset */
786 	usb_reset_device(serial->dev);
787 	return 0;
788 }
789 
790 static int __init cp210x_init(void)
791 {
792 	int retval;
793 
794 	retval = usb_serial_register(&cp210x_device);
795 	if (retval)
796 		return retval; /* Failed to register */
797 
798 	retval = usb_register(&cp210x_driver);
799 	if (retval) {
800 		/* Failed to register */
801 		usb_serial_deregister(&cp210x_device);
802 		return retval;
803 	}
804 
805 	/* Success */
806 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
807 	       DRIVER_DESC "\n");
808 	return 0;
809 }
810 
811 static void __exit cp210x_exit(void)
812 {
813 	usb_deregister(&cp210x_driver);
814 	usb_serial_deregister(&cp210x_device);
815 }
816 
817 module_init(cp210x_init);
818 module_exit(cp210x_exit);
819 
820 MODULE_DESCRIPTION(DRIVER_DESC);
821 MODULE_VERSION(DRIVER_VERSION);
822 MODULE_LICENSE("GPL");
823 
824 module_param(debug, bool, S_IRUGO | S_IWUSR);
825 MODULE_PARM_DESC(debug, "Enable verbose debugging messages");
826