xref: /linux/drivers/usb/serial/cp210x.c (revision 19c22c34dcbecb50c24548aa2ff2b07039c26c14)
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 *);
45 static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
46 static int cp210x_tiocmset_port(struct usb_serial_port *port,
47 		unsigned int, unsigned int);
48 static void cp210x_break_ctl(struct tty_struct *, int);
49 static int cp210x_startup(struct usb_serial *);
50 static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
51 
52 static bool debug;
53 
54 static const struct usb_device_id id_table[] = {
55 	{ USB_DEVICE(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
56 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
57 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
58 	{ USB_DEVICE(0x0489, 0xE003) }, /* 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, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
89 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
90 	{ USB_DEVICE(0x10C4, 0x8156) }, /* B&G H3000 link cable */
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, 0x81A9) }, /* Multiplex RC Interface */
96 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
97 	{ USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
98 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
99 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
100 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
101 	{ USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
102 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
103 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
104 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
105 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demonstration module */
106 	{ USB_DEVICE(0x10C4, 0x8293) }, /* Telegesis ETRX2USB */
107 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
108 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
109 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
110 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
111 	{ USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
112 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
113 	{ USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
114 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
115 	{ USB_DEVICE(0x10C4, 0x8477) }, /* Balluff RFID */
116 	{ USB_DEVICE(0x10C4, 0x85EA) }, /* AC-Services IBUS-IF */
117 	{ USB_DEVICE(0x10C4, 0x85EB) }, /* AC-Services CIS-IBUS */
118 	{ USB_DEVICE(0x10C4, 0x8664) }, /* AC-Services CAN-IF */
119 	{ USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
120 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
121 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
122 	{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
123 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
124 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
125 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
126 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
127 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
128 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
129 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
130 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
131 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
132 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
133 	{ USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
134 	{ USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
135 	{ USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
136 	{ USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
137 	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
138 	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
139 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
140 	{ USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
141 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
142 	{ } /* Terminating Entry */
143 };
144 
145 MODULE_DEVICE_TABLE(usb, id_table);
146 
147 static struct usb_driver cp210x_driver = {
148 	.name		= "cp210x",
149 	.probe		= usb_serial_probe,
150 	.disconnect	= usb_serial_disconnect,
151 	.id_table	= id_table,
152 	.no_dynamic_id	= 	1,
153 };
154 
155 static struct usb_serial_driver cp210x_device = {
156 	.driver = {
157 		.owner =	THIS_MODULE,
158 		.name = 	"cp210x",
159 	},
160 	.usb_driver		= &cp210x_driver,
161 	.id_table		= id_table,
162 	.num_ports		= 1,
163 	.bulk_in_size		= 256,
164 	.bulk_out_size		= 256,
165 	.open			= cp210x_open,
166 	.close			= cp210x_close,
167 	.break_ctl		= cp210x_break_ctl,
168 	.set_termios		= cp210x_set_termios,
169 	.tiocmget 		= cp210x_tiocmget,
170 	.tiocmset		= cp210x_tiocmset,
171 	.attach			= cp210x_startup,
172 	.dtr_rts		= cp210x_dtr_rts
173 };
174 
175 /* Config request types */
176 #define REQTYPE_HOST_TO_DEVICE	0x41
177 #define REQTYPE_DEVICE_TO_HOST	0xc1
178 
179 /* Config request codes */
180 #define CP210X_IFC_ENABLE	0x00
181 #define CP210X_SET_BAUDDIV	0x01
182 #define CP210X_GET_BAUDDIV	0x02
183 #define CP210X_SET_LINE_CTL	0x03
184 #define CP210X_GET_LINE_CTL	0x04
185 #define CP210X_SET_BREAK	0x05
186 #define CP210X_IMM_CHAR		0x06
187 #define CP210X_SET_MHS		0x07
188 #define CP210X_GET_MDMSTS	0x08
189 #define CP210X_SET_XON		0x09
190 #define CP210X_SET_XOFF		0x0A
191 #define CP210X_SET_EVENTMASK	0x0B
192 #define CP210X_GET_EVENTMASK	0x0C
193 #define CP210X_SET_CHAR		0x0D
194 #define CP210X_GET_CHARS	0x0E
195 #define CP210X_GET_PROPS	0x0F
196 #define CP210X_GET_COMM_STATUS	0x10
197 #define CP210X_RESET		0x11
198 #define CP210X_PURGE		0x12
199 #define CP210X_SET_FLOW		0x13
200 #define CP210X_GET_FLOW		0x14
201 #define CP210X_EMBED_EVENTS	0x15
202 #define CP210X_GET_EVENTSTATE	0x16
203 #define CP210X_SET_CHARS	0x19
204 
205 /* CP210X_IFC_ENABLE */
206 #define UART_ENABLE		0x0001
207 #define UART_DISABLE		0x0000
208 
209 /* CP210X_(SET|GET)_BAUDDIV */
210 #define BAUD_RATE_GEN_FREQ	0x384000
211 
212 /* CP210X_(SET|GET)_LINE_CTL */
213 #define BITS_DATA_MASK		0X0f00
214 #define BITS_DATA_5		0X0500
215 #define BITS_DATA_6		0X0600
216 #define BITS_DATA_7		0X0700
217 #define BITS_DATA_8		0X0800
218 #define BITS_DATA_9		0X0900
219 
220 #define BITS_PARITY_MASK	0x00f0
221 #define BITS_PARITY_NONE	0x0000
222 #define BITS_PARITY_ODD		0x0010
223 #define BITS_PARITY_EVEN	0x0020
224 #define BITS_PARITY_MARK	0x0030
225 #define BITS_PARITY_SPACE	0x0040
226 
227 #define BITS_STOP_MASK		0x000f
228 #define BITS_STOP_1		0x0000
229 #define BITS_STOP_1_5		0x0001
230 #define BITS_STOP_2		0x0002
231 
232 /* CP210X_SET_BREAK */
233 #define BREAK_ON		0x0001
234 #define BREAK_OFF		0x0000
235 
236 /* CP210X_(SET_MHS|GET_MDMSTS) */
237 #define CONTROL_DTR		0x0001
238 #define CONTROL_RTS		0x0002
239 #define CONTROL_CTS		0x0010
240 #define CONTROL_DSR		0x0020
241 #define CONTROL_RING		0x0040
242 #define CONTROL_DCD		0x0080
243 #define CONTROL_WRITE_DTR	0x0100
244 #define CONTROL_WRITE_RTS	0x0200
245 
246 /*
247  * cp210x_get_config
248  * Reads from the CP210x configuration registers
249  * 'size' is specified in bytes.
250  * 'data' is a pointer to a pre-allocated array of integers large
251  * enough to hold 'size' bytes (with 4 bytes to each integer)
252  */
253 static int cp210x_get_config(struct usb_serial_port *port, u8 request,
254 		unsigned int *data, int size)
255 {
256 	struct usb_serial *serial = port->serial;
257 	__le32 *buf;
258 	int result, i, length;
259 
260 	/* Number of integers required to contain the array */
261 	length = (((size - 1) | 3) + 1)/4;
262 
263 	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
264 	if (!buf) {
265 		dev_err(&port->dev, "%s - out of memory.\n", __func__);
266 		return -ENOMEM;
267 	}
268 
269 	/* Issue the request, attempting to read 'size' bytes */
270 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
271 				request, REQTYPE_DEVICE_TO_HOST, 0x0000,
272 				0, buf, size, 300);
273 
274 	/* Convert data into an array of integers */
275 	for (i = 0; i < length; i++)
276 		data[i] = le32_to_cpu(buf[i]);
277 
278 	kfree(buf);
279 
280 	if (result != size) {
281 		dbg("%s - Unable to send config request, "
282 				"request=0x%x size=%d result=%d\n",
283 				__func__, request, size, result);
284 		if (result > 0)
285 			result = -EPROTO;
286 
287 		return result;
288 	}
289 
290 	return 0;
291 }
292 
293 /*
294  * cp210x_set_config
295  * Writes to the CP210x configuration registers
296  * Values less than 16 bits wide are sent directly
297  * 'size' is specified in bytes.
298  */
299 static int cp210x_set_config(struct usb_serial_port *port, u8 request,
300 		unsigned int *data, int size)
301 {
302 	struct usb_serial *serial = port->serial;
303 	__le32 *buf;
304 	int result, i, length;
305 
306 	/* Number of integers required to contain the array */
307 	length = (((size - 1) | 3) + 1)/4;
308 
309 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
310 	if (!buf) {
311 		dev_err(&port->dev, "%s - out of memory.\n",
312 				__func__);
313 		return -ENOMEM;
314 	}
315 
316 	/* Array of integers into bytes */
317 	for (i = 0; i < length; i++)
318 		buf[i] = cpu_to_le32(data[i]);
319 
320 	if (size > 2) {
321 		result = usb_control_msg(serial->dev,
322 				usb_sndctrlpipe(serial->dev, 0),
323 				request, REQTYPE_HOST_TO_DEVICE, 0x0000,
324 				0, buf, size, 300);
325 	} else {
326 		result = usb_control_msg(serial->dev,
327 				usb_sndctrlpipe(serial->dev, 0),
328 				request, REQTYPE_HOST_TO_DEVICE, data[0],
329 				0, NULL, 0, 300);
330 	}
331 
332 	kfree(buf);
333 
334 	if ((size > 2 && result != size) || result < 0) {
335 		dbg("%s - Unable to send request, "
336 				"request=0x%x size=%d result=%d\n",
337 				__func__, request, size, result);
338 		if (result > 0)
339 			result = -EPROTO;
340 
341 		return result;
342 	}
343 
344 	return 0;
345 }
346 
347 /*
348  * cp210x_set_config_single
349  * Convenience function for calling cp210x_set_config on single data values
350  * without requiring an integer pointer
351  */
352 static inline int cp210x_set_config_single(struct usb_serial_port *port,
353 		u8 request, unsigned int data)
354 {
355 	return cp210x_set_config(port, request, &data, 2);
356 }
357 
358 /*
359  * cp210x_quantise_baudrate
360  * Quantises the baud rate as per AN205 Table 1
361  */
362 static unsigned int cp210x_quantise_baudrate(unsigned int baud) {
363 	if      (baud <= 56)       baud = 0;
364 	else if (baud <= 300)      baud = 300;
365 	else if (baud <= 600)      baud = 600;
366 	else if (baud <= 1200)     baud = 1200;
367 	else if (baud <= 1800)     baud = 1800;
368 	else if (baud <= 2400)     baud = 2400;
369 	else if (baud <= 4000)     baud = 4000;
370 	else if (baud <= 4803)     baud = 4800;
371 	else if (baud <= 7207)     baud = 7200;
372 	else if (baud <= 9612)     baud = 9600;
373 	else if (baud <= 14428)    baud = 14400;
374 	else if (baud <= 16062)    baud = 16000;
375 	else if (baud <= 19250)    baud = 19200;
376 	else if (baud <= 28912)    baud = 28800;
377 	else if (baud <= 38601)    baud = 38400;
378 	else if (baud <= 51558)    baud = 51200;
379 	else if (baud <= 56280)    baud = 56000;
380 	else if (baud <= 58053)    baud = 57600;
381 	else if (baud <= 64111)    baud = 64000;
382 	else if (baud <= 77608)    baud = 76800;
383 	else if (baud <= 117028)   baud = 115200;
384 	else if (baud <= 129347)   baud = 128000;
385 	else if (baud <= 156868)   baud = 153600;
386 	else if (baud <= 237832)   baud = 230400;
387 	else if (baud <= 254234)   baud = 250000;
388 	else if (baud <= 273066)   baud = 256000;
389 	else if (baud <= 491520)   baud = 460800;
390 	else if (baud <= 567138)   baud = 500000;
391 	else if (baud <= 670254)   baud = 576000;
392 	else if (baud <= 1053257)  baud = 921600;
393 	else if (baud <= 1474560)  baud = 1228800;
394 	else if (baud <= 2457600)  baud = 1843200;
395 	else                       baud = 3686400;
396 	return baud;
397 }
398 
399 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
400 {
401 	int result;
402 
403 	dbg("%s - port %d", __func__, port->number);
404 
405 	result = cp210x_set_config_single(port, CP210X_IFC_ENABLE,
406 								UART_ENABLE);
407 	if (result) {
408 		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
409 		return result;
410 	}
411 
412 	result = usb_serial_generic_open(tty, port);
413 	if (result)
414 		return result;
415 
416 	/* Configure the termios structure */
417 	cp210x_get_termios(tty, port);
418 	return 0;
419 }
420 
421 static void cp210x_close(struct usb_serial_port *port)
422 {
423 	dbg("%s - port %d", __func__, port->number);
424 
425 	usb_serial_generic_close(port);
426 
427 	mutex_lock(&port->serial->disc_mutex);
428 	if (!port->serial->disconnected)
429 		cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
430 	mutex_unlock(&port->serial->disc_mutex);
431 }
432 
433 /*
434  * cp210x_get_termios
435  * Reads the baud rate, data bits, parity, stop bits and flow control mode
436  * from the device, corrects any unsupported values, and configures the
437  * termios structure to reflect the state of the device
438  */
439 static void cp210x_get_termios(struct tty_struct *tty,
440 	struct usb_serial_port *port)
441 {
442 	unsigned int baud;
443 
444 	if (tty) {
445 		cp210x_get_termios_port(tty->driver_data,
446 			&tty->termios->c_cflag, &baud);
447 		tty_encode_baud_rate(tty, baud, baud);
448 	}
449 
450 	else {
451 		unsigned int cflag;
452 		cflag = 0;
453 		cp210x_get_termios_port(port, &cflag, &baud);
454 	}
455 }
456 
457 /*
458  * cp210x_get_termios_port
459  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
460  */
461 static void cp210x_get_termios_port(struct usb_serial_port *port,
462 	unsigned int *cflagp, unsigned int *baudp)
463 {
464 	unsigned int cflag, modem_ctl[4];
465 	unsigned int baud;
466 	unsigned int bits;
467 
468 	dbg("%s - port %d", __func__, port->number);
469 
470 	cp210x_get_config(port, CP210X_GET_BAUDDIV, &baud, 2);
471 	/* Convert to baudrate */
472 	if (baud)
473 		baud = cp210x_quantise_baudrate((BAUD_RATE_GEN_FREQ + baud/2)/ baud);
474 
475 	dbg("%s - baud rate = %d", __func__, baud);
476 	*baudp = baud;
477 
478 	cflag = *cflagp;
479 
480 	cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
481 	cflag &= ~CSIZE;
482 	switch (bits & BITS_DATA_MASK) {
483 	case BITS_DATA_5:
484 		dbg("%s - data bits = 5", __func__);
485 		cflag |= CS5;
486 		break;
487 	case BITS_DATA_6:
488 		dbg("%s - data bits = 6", __func__);
489 		cflag |= CS6;
490 		break;
491 	case BITS_DATA_7:
492 		dbg("%s - data bits = 7", __func__);
493 		cflag |= CS7;
494 		break;
495 	case BITS_DATA_8:
496 		dbg("%s - data bits = 8", __func__);
497 		cflag |= CS8;
498 		break;
499 	case BITS_DATA_9:
500 		dbg("%s - data bits = 9 (not supported, using 8 data bits)",
501 								__func__);
502 		cflag |= CS8;
503 		bits &= ~BITS_DATA_MASK;
504 		bits |= BITS_DATA_8;
505 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
506 		break;
507 	default:
508 		dbg("%s - Unknown number of data bits, using 8", __func__);
509 		cflag |= CS8;
510 		bits &= ~BITS_DATA_MASK;
511 		bits |= BITS_DATA_8;
512 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
513 		break;
514 	}
515 
516 	switch (bits & BITS_PARITY_MASK) {
517 	case BITS_PARITY_NONE:
518 		dbg("%s - parity = NONE", __func__);
519 		cflag &= ~PARENB;
520 		break;
521 	case BITS_PARITY_ODD:
522 		dbg("%s - parity = ODD", __func__);
523 		cflag |= (PARENB|PARODD);
524 		break;
525 	case BITS_PARITY_EVEN:
526 		dbg("%s - parity = EVEN", __func__);
527 		cflag &= ~PARODD;
528 		cflag |= PARENB;
529 		break;
530 	case BITS_PARITY_MARK:
531 		dbg("%s - parity = MARK", __func__);
532 		cflag |= (PARENB|PARODD|CMSPAR);
533 		break;
534 	case BITS_PARITY_SPACE:
535 		dbg("%s - parity = SPACE", __func__);
536 		cflag &= ~PARODD;
537 		cflag |= (PARENB|CMSPAR);
538 		break;
539 	default:
540 		dbg("%s - Unknown parity mode, disabling parity", __func__);
541 		cflag &= ~PARENB;
542 		bits &= ~BITS_PARITY_MASK;
543 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
544 		break;
545 	}
546 
547 	cflag &= ~CSTOPB;
548 	switch (bits & BITS_STOP_MASK) {
549 	case BITS_STOP_1:
550 		dbg("%s - stop bits = 1", __func__);
551 		break;
552 	case BITS_STOP_1_5:
553 		dbg("%s - stop bits = 1.5 (not supported, using 1 stop bit)",
554 								__func__);
555 		bits &= ~BITS_STOP_MASK;
556 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
557 		break;
558 	case BITS_STOP_2:
559 		dbg("%s - stop bits = 2", __func__);
560 		cflag |= CSTOPB;
561 		break;
562 	default:
563 		dbg("%s - Unknown number of stop bits, using 1 stop bit",
564 								__func__);
565 		bits &= ~BITS_STOP_MASK;
566 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
567 		break;
568 	}
569 
570 	cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
571 	if (modem_ctl[0] & 0x0008) {
572 		dbg("%s - flow control = CRTSCTS", __func__);
573 		cflag |= CRTSCTS;
574 	} else {
575 		dbg("%s - flow control = NONE", __func__);
576 		cflag &= ~CRTSCTS;
577 	}
578 
579 	*cflagp = cflag;
580 }
581 
582 static void cp210x_set_termios(struct tty_struct *tty,
583 		struct usb_serial_port *port, struct ktermios *old_termios)
584 {
585 	unsigned int cflag, old_cflag;
586 	unsigned int baud = 0, bits;
587 	unsigned int modem_ctl[4];
588 
589 	dbg("%s - port %d", __func__, port->number);
590 
591 	if (!tty)
592 		return;
593 
594 	cflag = tty->termios->c_cflag;
595 	old_cflag = old_termios->c_cflag;
596 	baud = cp210x_quantise_baudrate(tty_get_baud_rate(tty));
597 
598 	/* If the baud rate is to be updated*/
599 	if (baud != tty_termios_baud_rate(old_termios) && baud != 0) {
600 		dbg("%s - Setting baud rate to %d baud", __func__,
601 				baud);
602 		if (cp210x_set_config_single(port, CP210X_SET_BAUDDIV,
603 					((BAUD_RATE_GEN_FREQ + baud/2) / baud))) {
604 			dbg("Baud rate requested not supported by device");
605 			baud = tty_termios_baud_rate(old_termios);
606 		}
607 	}
608 	/* Report back the resulting baud rate */
609 	tty_encode_baud_rate(tty, baud, baud);
610 
611 	/* If the number of data bits is to be updated */
612 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
613 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
614 		bits &= ~BITS_DATA_MASK;
615 		switch (cflag & CSIZE) {
616 		case CS5:
617 			bits |= BITS_DATA_5;
618 			dbg("%s - data bits = 5", __func__);
619 			break;
620 		case CS6:
621 			bits |= BITS_DATA_6;
622 			dbg("%s - data bits = 6", __func__);
623 			break;
624 		case CS7:
625 			bits |= BITS_DATA_7;
626 			dbg("%s - data bits = 7", __func__);
627 			break;
628 		case CS8:
629 			bits |= BITS_DATA_8;
630 			dbg("%s - data bits = 8", __func__);
631 			break;
632 		/*case CS9:
633 			bits |= BITS_DATA_9;
634 			dbg("%s - data bits = 9", __func__);
635 			break;*/
636 		default:
637 			dbg("cp210x driver does not "
638 					"support the number of bits requested,"
639 					" using 8 bit mode\n");
640 				bits |= BITS_DATA_8;
641 				break;
642 		}
643 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
644 			dbg("Number of data bits requested "
645 					"not supported by device\n");
646 	}
647 
648 	if ((cflag     & (PARENB|PARODD|CMSPAR)) !=
649 	    (old_cflag & (PARENB|PARODD|CMSPAR))) {
650 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
651 		bits &= ~BITS_PARITY_MASK;
652 		if (cflag & PARENB) {
653 			if (cflag & CMSPAR) {
654 			    if (cflag & PARODD) {
655 				    bits |= BITS_PARITY_MARK;
656 				    dbg("%s - parity = MARK", __func__);
657 			    } else {
658 				    bits |= BITS_PARITY_SPACE;
659 				    dbg("%s - parity = SPACE", __func__);
660 			    }
661 			} else {
662 			    if (cflag & PARODD) {
663 				    bits |= BITS_PARITY_ODD;
664 				    dbg("%s - parity = ODD", __func__);
665 			    } else {
666 				    bits |= BITS_PARITY_EVEN;
667 				    dbg("%s - parity = EVEN", __func__);
668 			    }
669 			}
670 		}
671 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
672 			dbg("Parity mode not supported "
673 					"by device\n");
674 	}
675 
676 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
677 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
678 		bits &= ~BITS_STOP_MASK;
679 		if (cflag & CSTOPB) {
680 			bits |= BITS_STOP_2;
681 			dbg("%s - stop bits = 2", __func__);
682 		} else {
683 			bits |= BITS_STOP_1;
684 			dbg("%s - stop bits = 1", __func__);
685 		}
686 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
687 			dbg("Number of stop bits requested "
688 					"not supported by device\n");
689 	}
690 
691 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
692 		cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
693 		dbg("%s - read 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 
697 		if (cflag & CRTSCTS) {
698 			modem_ctl[0] &= ~0x7B;
699 			modem_ctl[0] |= 0x09;
700 			modem_ctl[1] = 0x80;
701 			dbg("%s - flow control = CRTSCTS", __func__);
702 		} else {
703 			modem_ctl[0] &= ~0x7B;
704 			modem_ctl[0] |= 0x01;
705 			modem_ctl[1] |= 0x40;
706 			dbg("%s - flow control = NONE", __func__);
707 		}
708 
709 		dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
710 				__func__, modem_ctl[0], modem_ctl[1],
711 				modem_ctl[2], modem_ctl[3]);
712 		cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
713 	}
714 
715 }
716 
717 static int cp210x_tiocmset (struct tty_struct *tty,
718 		unsigned int set, unsigned int clear)
719 {
720 	struct usb_serial_port *port = tty->driver_data;
721 	return cp210x_tiocmset_port(port, set, clear);
722 }
723 
724 static int cp210x_tiocmset_port(struct usb_serial_port *port,
725 		unsigned int set, unsigned int clear)
726 {
727 	unsigned int control = 0;
728 
729 	dbg("%s - port %d", __func__, port->number);
730 
731 	if (set & TIOCM_RTS) {
732 		control |= CONTROL_RTS;
733 		control |= CONTROL_WRITE_RTS;
734 	}
735 	if (set & TIOCM_DTR) {
736 		control |= CONTROL_DTR;
737 		control |= CONTROL_WRITE_DTR;
738 	}
739 	if (clear & TIOCM_RTS) {
740 		control &= ~CONTROL_RTS;
741 		control |= CONTROL_WRITE_RTS;
742 	}
743 	if (clear & TIOCM_DTR) {
744 		control &= ~CONTROL_DTR;
745 		control |= CONTROL_WRITE_DTR;
746 	}
747 
748 	dbg("%s - control = 0x%.4x", __func__, control);
749 
750 	return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
751 }
752 
753 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
754 {
755 	if (on)
756 		cp210x_tiocmset_port(p, TIOCM_DTR|TIOCM_RTS, 0);
757 	else
758 		cp210x_tiocmset_port(p, 0, TIOCM_DTR|TIOCM_RTS);
759 }
760 
761 static int cp210x_tiocmget (struct tty_struct *tty)
762 {
763 	struct usb_serial_port *port = tty->driver_data;
764 	unsigned int control;
765 	int result;
766 
767 	dbg("%s - port %d", __func__, port->number);
768 
769 	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
770 
771 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
772 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
773 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
774 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
775 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
776 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
777 
778 	dbg("%s - control = 0x%.2x", __func__, control);
779 
780 	return result;
781 }
782 
783 static void cp210x_break_ctl (struct tty_struct *tty, int break_state)
784 {
785 	struct usb_serial_port *port = tty->driver_data;
786 	unsigned int state;
787 
788 	dbg("%s - port %d", __func__, port->number);
789 	if (break_state == 0)
790 		state = BREAK_OFF;
791 	else
792 		state = BREAK_ON;
793 	dbg("%s - turning break %s", __func__,
794 			state == BREAK_OFF ? "off" : "on");
795 	cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
796 }
797 
798 static int cp210x_startup(struct usb_serial *serial)
799 {
800 	/* cp210x buffers behave strangely unless device is reset */
801 	usb_reset_device(serial->dev);
802 	return 0;
803 }
804 
805 static int __init cp210x_init(void)
806 {
807 	int retval;
808 
809 	retval = usb_serial_register(&cp210x_device);
810 	if (retval)
811 		return retval; /* Failed to register */
812 
813 	retval = usb_register(&cp210x_driver);
814 	if (retval) {
815 		/* Failed to register */
816 		usb_serial_deregister(&cp210x_device);
817 		return retval;
818 	}
819 
820 	/* Success */
821 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
822 	       DRIVER_DESC "\n");
823 	return 0;
824 }
825 
826 static void __exit cp210x_exit(void)
827 {
828 	usb_deregister(&cp210x_driver);
829 	usb_serial_deregister(&cp210x_device);
830 }
831 
832 module_init(cp210x_init);
833 module_exit(cp210x_exit);
834 
835 MODULE_DESCRIPTION(DRIVER_DESC);
836 MODULE_VERSION(DRIVER_VERSION);
837 MODULE_LICENSE("GPL");
838 
839 module_param(debug, bool, S_IRUGO | S_IWUSR);
840 MODULE_PARM_DESC(debug, "Enable verbose debugging messages");
841