xref: /linux/drivers/usb/serial/cp210x.c (revision 2f1136d1d08a63dcdbcd462621373f30d8dfe590)
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(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
58 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
59 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
60 	{ USB_DEVICE(0x0489, 0xE003) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
61 	{ USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
62 	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
63 	{ USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
64 	{ USB_DEVICE(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
65 	{ USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
66 	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
67 	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
68 	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
69 	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
70 	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
71 	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
72 	{ USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
73 	{ USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
74 	{ USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
75 	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
76 	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
77 	{ USB_DEVICE(0x10C4, 0x8044) }, /* Cygnal Debug Adapter */
78 	{ USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
79 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
80 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
81 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
82 	{ USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
83 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
84 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
85 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
86 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
87 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
88 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
89 	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
90 	{ USB_DEVICE(0x10C4, 0x8149) }, /* West Mountain Radio Computerized Battery Analyzer */
91 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
92 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
93 	{ USB_DEVICE(0x10C4, 0x8156) }, /* B&G H3000 link cable */
94 	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
95 	{ USB_DEVICE(0x10C4, 0x818B) }, /* AVIT Research USB to TTL */
96 	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
97 	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
98 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
99 	{ USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
100 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
101 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
102 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
103 	{ USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
104 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
105 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
106 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
107 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demostration module */
108 	{ USB_DEVICE(0x10C4, 0x8293) }, /* Telegesys ETRX2USB */
109 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
110 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
111 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
112 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
113 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
114 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
115 	{ USB_DEVICE(0x10C4, 0x8477) }, /* Balluff RFID */
116 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
117 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
118 	{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
119 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
120 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
121 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
122 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
123 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
124 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
125 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
126 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
127 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
128 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
129 	{ USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
130 	{ USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
131 	{ USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
132 	{ USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
133 	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
134 	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
135 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
136 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
137 	{ } /* Terminating Entry */
138 };
139 
140 MODULE_DEVICE_TABLE(usb, id_table);
141 
142 static struct usb_driver cp210x_driver = {
143 	.name		= "cp210x",
144 	.probe		= usb_serial_probe,
145 	.disconnect	= usb_serial_disconnect,
146 	.id_table	= id_table,
147 	.no_dynamic_id	= 	1,
148 };
149 
150 static struct usb_serial_driver cp210x_device = {
151 	.driver = {
152 		.owner =	THIS_MODULE,
153 		.name = 	"cp210x",
154 	},
155 	.usb_driver		= &cp210x_driver,
156 	.id_table		= id_table,
157 	.num_ports		= 1,
158 	.bulk_in_size		= 256,
159 	.bulk_out_size		= 256,
160 	.open			= cp210x_open,
161 	.close			= cp210x_close,
162 	.break_ctl		= cp210x_break_ctl,
163 	.set_termios		= cp210x_set_termios,
164 	.tiocmget 		= cp210x_tiocmget,
165 	.tiocmset		= cp210x_tiocmset,
166 	.attach			= cp210x_startup,
167 	.dtr_rts		= cp210x_dtr_rts,
168 	.carrier_raised		= cp210x_carrier_raised
169 };
170 
171 /* Config request types */
172 #define REQTYPE_HOST_TO_DEVICE	0x41
173 #define REQTYPE_DEVICE_TO_HOST	0xc1
174 
175 /* Config request codes */
176 #define CP210X_IFC_ENABLE	0x00
177 #define CP210X_SET_BAUDDIV	0x01
178 #define CP210X_GET_BAUDDIV	0x02
179 #define CP210X_SET_LINE_CTL	0x03
180 #define CP210X_GET_LINE_CTL	0x04
181 #define CP210X_SET_BREAK	0x05
182 #define CP210X_IMM_CHAR		0x06
183 #define CP210X_SET_MHS		0x07
184 #define CP210X_GET_MDMSTS	0x08
185 #define CP210X_SET_XON		0x09
186 #define CP210X_SET_XOFF		0x0A
187 #define CP210X_SET_EVENTMASK	0x0B
188 #define CP210X_GET_EVENTMASK	0x0C
189 #define CP210X_SET_CHAR		0x0D
190 #define CP210X_GET_CHARS	0x0E
191 #define CP210X_GET_PROPS	0x0F
192 #define CP210X_GET_COMM_STATUS	0x10
193 #define CP210X_RESET		0x11
194 #define CP210X_PURGE		0x12
195 #define CP210X_SET_FLOW		0x13
196 #define CP210X_GET_FLOW		0x14
197 #define CP210X_EMBED_EVENTS	0x15
198 #define CP210X_GET_EVENTSTATE	0x16
199 #define CP210X_SET_CHARS	0x19
200 
201 /* CP210X_IFC_ENABLE */
202 #define UART_ENABLE		0x0001
203 #define UART_DISABLE		0x0000
204 
205 /* CP210X_(SET|GET)_BAUDDIV */
206 #define BAUD_RATE_GEN_FREQ	0x384000
207 
208 /* CP210X_(SET|GET)_LINE_CTL */
209 #define BITS_DATA_MASK		0X0f00
210 #define BITS_DATA_5		0X0500
211 #define BITS_DATA_6		0X0600
212 #define BITS_DATA_7		0X0700
213 #define BITS_DATA_8		0X0800
214 #define BITS_DATA_9		0X0900
215 
216 #define BITS_PARITY_MASK	0x00f0
217 #define BITS_PARITY_NONE	0x0000
218 #define BITS_PARITY_ODD		0x0010
219 #define BITS_PARITY_EVEN	0x0020
220 #define BITS_PARITY_MARK	0x0030
221 #define BITS_PARITY_SPACE	0x0040
222 
223 #define BITS_STOP_MASK		0x000f
224 #define BITS_STOP_1		0x0000
225 #define BITS_STOP_1_5		0x0001
226 #define BITS_STOP_2		0x0002
227 
228 /* CP210X_SET_BREAK */
229 #define BREAK_ON		0x0001
230 #define BREAK_OFF		0x0000
231 
232 /* CP210X_(SET_MHS|GET_MDMSTS) */
233 #define CONTROL_DTR		0x0001
234 #define CONTROL_RTS		0x0002
235 #define CONTROL_CTS		0x0010
236 #define CONTROL_DSR		0x0020
237 #define CONTROL_RING		0x0040
238 #define CONTROL_DCD		0x0080
239 #define CONTROL_WRITE_DTR	0x0100
240 #define CONTROL_WRITE_RTS	0x0200
241 
242 /*
243  * cp210x_get_config
244  * Reads from the CP210x configuration registers
245  * 'size' is specified in bytes.
246  * 'data' is a pointer to a pre-allocated array of integers large
247  * enough to hold 'size' bytes (with 4 bytes to each integer)
248  */
249 static int cp210x_get_config(struct usb_serial_port *port, u8 request,
250 		unsigned int *data, int size)
251 {
252 	struct usb_serial *serial = port->serial;
253 	__le32 *buf;
254 	int result, i, length;
255 
256 	/* Number of integers required to contain the array */
257 	length = (((size - 1) | 3) + 1)/4;
258 
259 	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
260 	if (!buf) {
261 		dev_err(&port->dev, "%s - out of memory.\n", __func__);
262 		return -ENOMEM;
263 	}
264 
265 	/* Issue the request, attempting to read 'size' bytes */
266 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
267 				request, REQTYPE_DEVICE_TO_HOST, 0x0000,
268 				0, buf, size, 300);
269 
270 	/* Convert data into an array of integers */
271 	for (i = 0; i < length; i++)
272 		data[i] = le32_to_cpu(buf[i]);
273 
274 	kfree(buf);
275 
276 	if (result != size) {
277 		dbg("%s - Unable to send config request, "
278 				"request=0x%x size=%d result=%d\n",
279 				__func__, request, size, result);
280 		return -EPROTO;
281 	}
282 
283 	return 0;
284 }
285 
286 /*
287  * cp210x_set_config
288  * Writes to the CP210x configuration registers
289  * Values less than 16 bits wide are sent directly
290  * 'size' is specified in bytes.
291  */
292 static int cp210x_set_config(struct usb_serial_port *port, u8 request,
293 		unsigned int *data, int size)
294 {
295 	struct usb_serial *serial = port->serial;
296 	__le32 *buf;
297 	int result, i, length;
298 
299 	/* Number of integers required to contain the array */
300 	length = (((size - 1) | 3) + 1)/4;
301 
302 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
303 	if (!buf) {
304 		dev_err(&port->dev, "%s - out of memory.\n",
305 				__func__);
306 		return -ENOMEM;
307 	}
308 
309 	/* Array of integers into bytes */
310 	for (i = 0; i < length; i++)
311 		buf[i] = cpu_to_le32(data[i]);
312 
313 	if (size > 2) {
314 		result = usb_control_msg(serial->dev,
315 				usb_sndctrlpipe(serial->dev, 0),
316 				request, REQTYPE_HOST_TO_DEVICE, 0x0000,
317 				0, buf, size, 300);
318 	} else {
319 		result = usb_control_msg(serial->dev,
320 				usb_sndctrlpipe(serial->dev, 0),
321 				request, REQTYPE_HOST_TO_DEVICE, data[0],
322 				0, NULL, 0, 300);
323 	}
324 
325 	kfree(buf);
326 
327 	if ((size > 2 && result != size) || result < 0) {
328 		dbg("%s - Unable to send request, "
329 				"request=0x%x size=%d result=%d\n",
330 				__func__, request, size, result);
331 		return -EPROTO;
332 	}
333 
334 	return 0;
335 }
336 
337 /*
338  * cp210x_set_config_single
339  * Convenience function for calling cp210x_set_config on single data values
340  * without requiring an integer pointer
341  */
342 static inline int cp210x_set_config_single(struct usb_serial_port *port,
343 		u8 request, unsigned int data)
344 {
345 	return cp210x_set_config(port, request, &data, 2);
346 }
347 
348 /*
349  * cp210x_quantise_baudrate
350  * Quantises the baud rate as per AN205 Table 1
351  */
352 static unsigned int cp210x_quantise_baudrate(unsigned int baud) {
353 	if      (baud <= 56)       baud = 0;
354 	else if (baud <= 300)      baud = 300;
355 	else if (baud <= 600)      baud = 600;
356 	else if (baud <= 1200)     baud = 1200;
357 	else if (baud <= 1800)     baud = 1800;
358 	else if (baud <= 2400)     baud = 2400;
359 	else if (baud <= 4000)     baud = 4000;
360 	else if (baud <= 4803)     baud = 4800;
361 	else if (baud <= 7207)     baud = 7200;
362 	else if (baud <= 9612)     baud = 9600;
363 	else if (baud <= 14428)    baud = 14400;
364 	else if (baud <= 16062)    baud = 16000;
365 	else if (baud <= 19250)    baud = 19200;
366 	else if (baud <= 28912)    baud = 28800;
367 	else if (baud <= 38601)    baud = 38400;
368 	else if (baud <= 51558)    baud = 51200;
369 	else if (baud <= 56280)    baud = 56000;
370 	else if (baud <= 58053)    baud = 57600;
371 	else if (baud <= 64111)    baud = 64000;
372 	else if (baud <= 77608)    baud = 76800;
373 	else if (baud <= 117028)   baud = 115200;
374 	else if (baud <= 129347)   baud = 128000;
375 	else if (baud <= 156868)   baud = 153600;
376 	else if (baud <= 237832)   baud = 230400;
377 	else if (baud <= 254234)   baud = 250000;
378 	else if (baud <= 273066)   baud = 256000;
379 	else if (baud <= 491520)   baud = 460800;
380 	else if (baud <= 567138)   baud = 500000;
381 	else if (baud <= 670254)   baud = 576000;
382 	else if (baud <= 1053257)  baud = 921600;
383 	else if (baud <= 1474560)  baud = 1228800;
384 	else if (baud <= 2457600)  baud = 1843200;
385 	else                       baud = 3686400;
386 	return baud;
387 }
388 
389 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
390 {
391 	int result;
392 
393 	dbg("%s - port %d", __func__, port->number);
394 
395 	if (cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_ENABLE)) {
396 		dev_err(&port->dev, "%s - Unable to enable UART\n",
397 				__func__);
398 		return -EPROTO;
399 	}
400 
401 	result = usb_serial_generic_open(tty, port);
402 	if (result)
403 		return result;
404 
405 	/* Configure the termios structure */
406 	cp210x_get_termios(tty, port);
407 	return 0;
408 }
409 
410 static void cp210x_close(struct usb_serial_port *port)
411 {
412 	dbg("%s - port %d", __func__, port->number);
413 
414 	usb_serial_generic_close(port);
415 
416 	mutex_lock(&port->serial->disc_mutex);
417 	if (!port->serial->disconnected)
418 		cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
419 	mutex_unlock(&port->serial->disc_mutex);
420 }
421 
422 /*
423  * cp210x_get_termios
424  * Reads the baud rate, data bits, parity, stop bits and flow control mode
425  * from the device, corrects any unsupported values, and configures the
426  * termios structure to reflect the state of the device
427  */
428 static void cp210x_get_termios(struct tty_struct *tty,
429 	struct usb_serial_port *port)
430 {
431 	unsigned int baud;
432 
433 	if (tty) {
434 		cp210x_get_termios_port(tty->driver_data,
435 			&tty->termios->c_cflag, &baud);
436 		tty_encode_baud_rate(tty, baud, baud);
437 	}
438 
439 	else {
440 		unsigned int cflag;
441 		cflag = 0;
442 		cp210x_get_termios_port(port, &cflag, &baud);
443 	}
444 }
445 
446 /*
447  * cp210x_get_termios_port
448  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
449  */
450 static void cp210x_get_termios_port(struct usb_serial_port *port,
451 	unsigned int *cflagp, unsigned int *baudp)
452 {
453 	unsigned int cflag, modem_ctl[4];
454 	unsigned int baud;
455 	unsigned int bits;
456 
457 	dbg("%s - port %d", __func__, port->number);
458 
459 	cp210x_get_config(port, CP210X_GET_BAUDDIV, &baud, 2);
460 	/* Convert to baudrate */
461 	if (baud)
462 		baud = cp210x_quantise_baudrate((BAUD_RATE_GEN_FREQ + baud/2)/ baud);
463 
464 	dbg("%s - baud rate = %d", __func__, baud);
465 	*baudp = baud;
466 
467 	cflag = *cflagp;
468 
469 	cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
470 	cflag &= ~CSIZE;
471 	switch (bits & BITS_DATA_MASK) {
472 	case BITS_DATA_5:
473 		dbg("%s - data bits = 5", __func__);
474 		cflag |= CS5;
475 		break;
476 	case BITS_DATA_6:
477 		dbg("%s - data bits = 6", __func__);
478 		cflag |= CS6;
479 		break;
480 	case BITS_DATA_7:
481 		dbg("%s - data bits = 7", __func__);
482 		cflag |= CS7;
483 		break;
484 	case BITS_DATA_8:
485 		dbg("%s - data bits = 8", __func__);
486 		cflag |= CS8;
487 		break;
488 	case BITS_DATA_9:
489 		dbg("%s - data bits = 9 (not supported, using 8 data bits)",
490 								__func__);
491 		cflag |= CS8;
492 		bits &= ~BITS_DATA_MASK;
493 		bits |= BITS_DATA_8;
494 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
495 		break;
496 	default:
497 		dbg("%s - Unknown number of data bits, using 8", __func__);
498 		cflag |= CS8;
499 		bits &= ~BITS_DATA_MASK;
500 		bits |= BITS_DATA_8;
501 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
502 		break;
503 	}
504 
505 	switch (bits & BITS_PARITY_MASK) {
506 	case BITS_PARITY_NONE:
507 		dbg("%s - parity = NONE", __func__);
508 		cflag &= ~PARENB;
509 		break;
510 	case BITS_PARITY_ODD:
511 		dbg("%s - parity = ODD", __func__);
512 		cflag |= (PARENB|PARODD);
513 		break;
514 	case BITS_PARITY_EVEN:
515 		dbg("%s - parity = EVEN", __func__);
516 		cflag &= ~PARODD;
517 		cflag |= PARENB;
518 		break;
519 	case BITS_PARITY_MARK:
520 		dbg("%s - parity = MARK (not supported, disabling parity)",
521 				__func__);
522 		cflag &= ~PARENB;
523 		bits &= ~BITS_PARITY_MASK;
524 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
525 		break;
526 	case BITS_PARITY_SPACE:
527 		dbg("%s - parity = SPACE (not supported, disabling parity)",
528 				__func__);
529 		cflag &= ~PARENB;
530 		bits &= ~BITS_PARITY_MASK;
531 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
532 		break;
533 	default:
534 		dbg("%s - Unknown parity mode, disabling parity", __func__);
535 		cflag &= ~PARENB;
536 		bits &= ~BITS_PARITY_MASK;
537 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
538 		break;
539 	}
540 
541 	cflag &= ~CSTOPB;
542 	switch (bits & BITS_STOP_MASK) {
543 	case BITS_STOP_1:
544 		dbg("%s - stop bits = 1", __func__);
545 		break;
546 	case BITS_STOP_1_5:
547 		dbg("%s - stop bits = 1.5 (not supported, using 1 stop bit)",
548 								__func__);
549 		bits &= ~BITS_STOP_MASK;
550 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
551 		break;
552 	case BITS_STOP_2:
553 		dbg("%s - stop bits = 2", __func__);
554 		cflag |= CSTOPB;
555 		break;
556 	default:
557 		dbg("%s - Unknown number of stop bits, using 1 stop bit",
558 								__func__);
559 		bits &= ~BITS_STOP_MASK;
560 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
561 		break;
562 	}
563 
564 	cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
565 	if (modem_ctl[0] & 0x0008) {
566 		dbg("%s - flow control = CRTSCTS", __func__);
567 		cflag |= CRTSCTS;
568 	} else {
569 		dbg("%s - flow control = NONE", __func__);
570 		cflag &= ~CRTSCTS;
571 	}
572 
573 	*cflagp = cflag;
574 }
575 
576 static void cp210x_set_termios(struct tty_struct *tty,
577 		struct usb_serial_port *port, struct ktermios *old_termios)
578 {
579 	unsigned int cflag, old_cflag;
580 	unsigned int baud = 0, bits;
581 	unsigned int modem_ctl[4];
582 
583 	dbg("%s - port %d", __func__, port->number);
584 
585 	if (!tty)
586 		return;
587 
588 	tty->termios->c_cflag &= ~CMSPAR;
589 	cflag = tty->termios->c_cflag;
590 	old_cflag = old_termios->c_cflag;
591 	baud = cp210x_quantise_baudrate(tty_get_baud_rate(tty));
592 
593 	/* If the baud rate is to be updated*/
594 	if (baud != tty_termios_baud_rate(old_termios) && baud != 0) {
595 		dbg("%s - Setting baud rate to %d baud", __func__,
596 				baud);
597 		if (cp210x_set_config_single(port, CP210X_SET_BAUDDIV,
598 					((BAUD_RATE_GEN_FREQ + baud/2) / baud))) {
599 			dbg("Baud rate requested not supported by device");
600 			baud = tty_termios_baud_rate(old_termios);
601 		}
602 	}
603 	/* Report back the resulting baud rate */
604 	tty_encode_baud_rate(tty, baud, baud);
605 
606 	/* If the number of data bits is to be updated */
607 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
608 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
609 		bits &= ~BITS_DATA_MASK;
610 		switch (cflag & CSIZE) {
611 		case CS5:
612 			bits |= BITS_DATA_5;
613 			dbg("%s - data bits = 5", __func__);
614 			break;
615 		case CS6:
616 			bits |= BITS_DATA_6;
617 			dbg("%s - data bits = 6", __func__);
618 			break;
619 		case CS7:
620 			bits |= BITS_DATA_7;
621 			dbg("%s - data bits = 7", __func__);
622 			break;
623 		case CS8:
624 			bits |= BITS_DATA_8;
625 			dbg("%s - data bits = 8", __func__);
626 			break;
627 		/*case CS9:
628 			bits |= BITS_DATA_9;
629 			dbg("%s - data bits = 9", __func__);
630 			break;*/
631 		default:
632 			dbg("cp210x driver does not "
633 					"support the number of bits requested,"
634 					" using 8 bit mode\n");
635 				bits |= BITS_DATA_8;
636 				break;
637 		}
638 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
639 			dbg("Number of data bits requested "
640 					"not supported by device\n");
641 	}
642 
643 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) {
644 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
645 		bits &= ~BITS_PARITY_MASK;
646 		if (cflag & PARENB) {
647 			if (cflag & PARODD) {
648 				bits |= BITS_PARITY_ODD;
649 				dbg("%s - parity = ODD", __func__);
650 			} else {
651 				bits |= BITS_PARITY_EVEN;
652 				dbg("%s - parity = EVEN", __func__);
653 			}
654 		}
655 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
656 			dbg("Parity mode not supported "
657 					"by device\n");
658 	}
659 
660 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
661 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
662 		bits &= ~BITS_STOP_MASK;
663 		if (cflag & CSTOPB) {
664 			bits |= BITS_STOP_2;
665 			dbg("%s - stop bits = 2", __func__);
666 		} else {
667 			bits |= BITS_STOP_1;
668 			dbg("%s - stop bits = 1", __func__);
669 		}
670 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
671 			dbg("Number of stop bits requested "
672 					"not supported by device\n");
673 	}
674 
675 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
676 		cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
677 		dbg("%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
678 				__func__, modem_ctl[0], modem_ctl[1],
679 				modem_ctl[2], modem_ctl[3]);
680 
681 		if (cflag & CRTSCTS) {
682 			modem_ctl[0] &= ~0x7B;
683 			modem_ctl[0] |= 0x09;
684 			modem_ctl[1] = 0x80;
685 			dbg("%s - flow control = CRTSCTS", __func__);
686 		} else {
687 			modem_ctl[0] &= ~0x7B;
688 			modem_ctl[0] |= 0x01;
689 			modem_ctl[1] |= 0x40;
690 			dbg("%s - flow control = NONE", __func__);
691 		}
692 
693 		dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
694 				__func__, modem_ctl[0], modem_ctl[1],
695 				modem_ctl[2], modem_ctl[3]);
696 		cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
697 	}
698 
699 }
700 
701 static int cp210x_tiocmset (struct tty_struct *tty, struct file *file,
702 		unsigned int set, unsigned int clear)
703 {
704 	struct usb_serial_port *port = tty->driver_data;
705 	return cp210x_tiocmset_port(port, file, set, clear);
706 }
707 
708 static int cp210x_tiocmset_port(struct usb_serial_port *port, struct file *file,
709 		unsigned int set, unsigned int clear)
710 {
711 	unsigned int control = 0;
712 
713 	dbg("%s - port %d", __func__, port->number);
714 
715 	if (set & TIOCM_RTS) {
716 		control |= CONTROL_RTS;
717 		control |= CONTROL_WRITE_RTS;
718 	}
719 	if (set & TIOCM_DTR) {
720 		control |= CONTROL_DTR;
721 		control |= CONTROL_WRITE_DTR;
722 	}
723 	if (clear & TIOCM_RTS) {
724 		control &= ~CONTROL_RTS;
725 		control |= CONTROL_WRITE_RTS;
726 	}
727 	if (clear & TIOCM_DTR) {
728 		control &= ~CONTROL_DTR;
729 		control |= CONTROL_WRITE_DTR;
730 	}
731 
732 	dbg("%s - control = 0x%.4x", __func__, control);
733 
734 	return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
735 }
736 
737 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
738 {
739 	if (on)
740 		cp210x_tiocmset_port(p, NULL,  TIOCM_DTR|TIOCM_RTS, 0);
741 	else
742 		cp210x_tiocmset_port(p, NULL,  0, TIOCM_DTR|TIOCM_RTS);
743 }
744 
745 static int cp210x_tiocmget (struct tty_struct *tty, struct file *file)
746 {
747 	struct usb_serial_port *port = tty->driver_data;
748 	unsigned int control;
749 	int result;
750 
751 	dbg("%s - port %d", __func__, port->number);
752 
753 	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
754 
755 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
756 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
757 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
758 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
759 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
760 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
761 
762 	dbg("%s - control = 0x%.2x", __func__, control);
763 
764 	return result;
765 }
766 
767 static int cp210x_carrier_raised(struct usb_serial_port *p)
768 {
769 	unsigned int control;
770 	cp210x_get_config(p, CP210X_GET_MDMSTS, &control, 1);
771 	if (control & CONTROL_DCD)
772 		return 1;
773 	return 0;
774 }
775 
776 static void cp210x_break_ctl (struct tty_struct *tty, int break_state)
777 {
778 	struct usb_serial_port *port = tty->driver_data;
779 	unsigned int state;
780 
781 	dbg("%s - port %d", __func__, port->number);
782 	if (break_state == 0)
783 		state = BREAK_OFF;
784 	else
785 		state = BREAK_ON;
786 	dbg("%s - turning break %s", __func__,
787 			state == BREAK_OFF ? "off" : "on");
788 	cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
789 }
790 
791 static int cp210x_startup(struct usb_serial *serial)
792 {
793 	/* cp210x buffers behave strangely unless device is reset */
794 	usb_reset_device(serial->dev);
795 	return 0;
796 }
797 
798 static int __init cp210x_init(void)
799 {
800 	int retval;
801 
802 	retval = usb_serial_register(&cp210x_device);
803 	if (retval)
804 		return retval; /* Failed to register */
805 
806 	retval = usb_register(&cp210x_driver);
807 	if (retval) {
808 		/* Failed to register */
809 		usb_serial_deregister(&cp210x_device);
810 		return retval;
811 	}
812 
813 	/* Success */
814 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
815 	       DRIVER_DESC "\n");
816 	return 0;
817 }
818 
819 static void __exit cp210x_exit(void)
820 {
821 	usb_deregister(&cp210x_driver);
822 	usb_serial_deregister(&cp210x_device);
823 }
824 
825 module_init(cp210x_init);
826 module_exit(cp210x_exit);
827 
828 MODULE_DESCRIPTION(DRIVER_DESC);
829 MODULE_VERSION(DRIVER_VERSION);
830 MODULE_LICENSE("GPL");
831 
832 module_param(debug, bool, S_IRUGO | S_IWUSR);
833 MODULE_PARM_DESC(debug, "Enable verbose debugging messages");
834