xref: /openbmc/linux/drivers/usb/serial/cp210x.c (revision 46557bef3f3834ac33031c7be27d39d90d507442)
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_cleanup(struct usb_serial_port *);
38 static void cp210x_close(struct usb_serial_port *);
39 static void cp210x_get_termios(struct tty_struct *,
40 	struct usb_serial_port *port);
41 static void cp210x_get_termios_port(struct usb_serial_port *port,
42 	unsigned int *cflagp, unsigned int *baudp);
43 static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
44 							struct ktermios*);
45 static int cp210x_tiocmget(struct tty_struct *, struct file *);
46 static int cp210x_tiocmset(struct tty_struct *, struct file *,
47 		unsigned int, unsigned int);
48 static int cp210x_tiocmset_port(struct usb_serial_port *port, struct file *,
49 		unsigned int, unsigned int);
50 static void cp210x_break_ctl(struct tty_struct *, int);
51 static int cp210x_startup(struct usb_serial *);
52 static void cp210x_disconnect(struct usb_serial *);
53 
54 static int debug;
55 
56 static 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(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, 0x0F91) }, /* Vstabi */
69 	{ USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
70 	{ USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
71 	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
72 	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
73 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
74 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
75 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
76 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
77 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
78 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
79 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
80 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
81 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
82 	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
83 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
84 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
85 	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
86 	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
87 	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
88 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
89 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
90 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
91 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
92 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
93 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
94 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
95 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demostration module */
96 	{ USB_DEVICE(0x10c4, 0x8293) }, /* Telegesys ETRX2USB */
97 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
98 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
99 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
100 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
101 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
102 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
103 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
104 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
105 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
106 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
107 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
108 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
109 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
110 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
111 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
112 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
113 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
114 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
115 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
116 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
117 	{ } /* Terminating Entry */
118 };
119 
120 MODULE_DEVICE_TABLE(usb, id_table);
121 
122 static struct usb_driver cp210x_driver = {
123 	.name		= "cp210x",
124 	.probe		= usb_serial_probe,
125 	.disconnect	= usb_serial_disconnect,
126 	.id_table	= id_table,
127 	.no_dynamic_id	= 	1,
128 };
129 
130 static struct usb_serial_driver cp210x_device = {
131 	.driver = {
132 		.owner =	THIS_MODULE,
133 		.name = 	"cp210x",
134 	},
135 	.usb_driver		= &cp210x_driver,
136 	.id_table		= id_table,
137 	.num_ports		= 1,
138 	.open			= cp210x_open,
139 	.close			= cp210x_close,
140 	.break_ctl		= cp210x_break_ctl,
141 	.set_termios		= cp210x_set_termios,
142 	.tiocmget 		= cp210x_tiocmget,
143 	.tiocmset		= cp210x_tiocmset,
144 	.attach			= cp210x_startup,
145 	.disconnect		= cp210x_disconnect,
146 };
147 
148 /* Config request types */
149 #define REQTYPE_HOST_TO_DEVICE	0x41
150 #define REQTYPE_DEVICE_TO_HOST	0xc1
151 
152 /* Config request codes */
153 #define CP210X_IFC_ENABLE	0x00
154 #define CP210X_SET_BAUDDIV	0x01
155 #define CP210X_GET_BAUDDIV	0x02
156 #define CP210X_SET_LINE_CTL	0x03
157 #define CP210X_GET_LINE_CTL	0x04
158 #define CP210X_SET_BREAK	0x05
159 #define CP210X_IMM_CHAR		0x06
160 #define CP210X_SET_MHS		0x07
161 #define CP210X_GET_MDMSTS	0x08
162 #define CP210X_SET_XON		0x09
163 #define CP210X_SET_XOFF		0x0A
164 #define CP210X_SET_EVENTMASK	0x0B
165 #define CP210X_GET_EVENTMASK	0x0C
166 #define CP210X_SET_CHAR		0x0D
167 #define CP210X_GET_CHARS	0x0E
168 #define CP210X_GET_PROPS	0x0F
169 #define CP210X_GET_COMM_STATUS	0x10
170 #define CP210X_RESET		0x11
171 #define CP210X_PURGE		0x12
172 #define CP210X_SET_FLOW		0x13
173 #define CP210X_GET_FLOW		0x14
174 #define CP210X_EMBED_EVENTS	0x15
175 #define CP210X_GET_EVENTSTATE	0x16
176 #define CP210X_SET_CHARS	0x19
177 
178 /* CP210X_IFC_ENABLE */
179 #define UART_ENABLE		0x0001
180 #define UART_DISABLE		0x0000
181 
182 /* CP210X_(SET|GET)_BAUDDIV */
183 #define BAUD_RATE_GEN_FREQ	0x384000
184 
185 /* CP210X_(SET|GET)_LINE_CTL */
186 #define BITS_DATA_MASK		0X0f00
187 #define BITS_DATA_5		0X0500
188 #define BITS_DATA_6		0X0600
189 #define BITS_DATA_7		0X0700
190 #define BITS_DATA_8		0X0800
191 #define BITS_DATA_9		0X0900
192 
193 #define BITS_PARITY_MASK	0x00f0
194 #define BITS_PARITY_NONE	0x0000
195 #define BITS_PARITY_ODD		0x0010
196 #define BITS_PARITY_EVEN	0x0020
197 #define BITS_PARITY_MARK	0x0030
198 #define BITS_PARITY_SPACE	0x0040
199 
200 #define BITS_STOP_MASK		0x000f
201 #define BITS_STOP_1		0x0000
202 #define BITS_STOP_1_5		0x0001
203 #define BITS_STOP_2		0x0002
204 
205 /* CP210X_SET_BREAK */
206 #define BREAK_ON		0x0000
207 #define BREAK_OFF		0x0001
208 
209 /* CP210X_(SET_MHS|GET_MDMSTS) */
210 #define CONTROL_DTR		0x0001
211 #define CONTROL_RTS		0x0002
212 #define CONTROL_CTS		0x0010
213 #define CONTROL_DSR		0x0020
214 #define CONTROL_RING		0x0040
215 #define CONTROL_DCD		0x0080
216 #define CONTROL_WRITE_DTR	0x0100
217 #define CONTROL_WRITE_RTS	0x0200
218 
219 /*
220  * cp210x_get_config
221  * Reads from the CP210x configuration registers
222  * 'size' is specified in bytes.
223  * 'data' is a pointer to a pre-allocated array of integers large
224  * enough to hold 'size' bytes (with 4 bytes to each integer)
225  */
226 static int cp210x_get_config(struct usb_serial_port *port, u8 request,
227 		unsigned int *data, int size)
228 {
229 	struct usb_serial *serial = port->serial;
230 	__le32 *buf;
231 	int result, i, length;
232 
233 	/* Number of integers required to contain the array */
234 	length = (((size - 1) | 3) + 1)/4;
235 
236 	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
237 	if (!buf) {
238 		dev_err(&port->dev, "%s - out of memory.\n", __func__);
239 		return -ENOMEM;
240 	}
241 
242 	/* Issue the request, attempting to read 'size' bytes */
243 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
244 				request, REQTYPE_DEVICE_TO_HOST, 0x0000,
245 				0, buf, size, 300);
246 
247 	/* Convert data into an array of integers */
248 	for (i = 0; i < length; i++)
249 		data[i] = le32_to_cpu(buf[i]);
250 
251 	kfree(buf);
252 
253 	if (result != size) {
254 		dbg("%s - Unable to send config request, "
255 				"request=0x%x size=%d result=%d\n",
256 				__func__, request, size, result);
257 		return -EPROTO;
258 	}
259 
260 	return 0;
261 }
262 
263 /*
264  * cp210x_set_config
265  * Writes to the CP210x configuration registers
266  * Values less than 16 bits wide are sent directly
267  * 'size' is specified in bytes.
268  */
269 static int cp210x_set_config(struct usb_serial_port *port, u8 request,
270 		unsigned int *data, int size)
271 {
272 	struct usb_serial *serial = port->serial;
273 	__le32 *buf;
274 	int result, i, length;
275 
276 	/* Number of integers required to contain the array */
277 	length = (((size - 1) | 3) + 1)/4;
278 
279 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
280 	if (!buf) {
281 		dev_err(&port->dev, "%s - out of memory.\n",
282 				__func__);
283 		return -ENOMEM;
284 	}
285 
286 	/* Array of integers into bytes */
287 	for (i = 0; i < length; i++)
288 		buf[i] = cpu_to_le32(data[i]);
289 
290 	if (size > 2) {
291 		result = usb_control_msg(serial->dev,
292 				usb_sndctrlpipe(serial->dev, 0),
293 				request, REQTYPE_HOST_TO_DEVICE, 0x0000,
294 				0, buf, size, 300);
295 	} else {
296 		result = usb_control_msg(serial->dev,
297 				usb_sndctrlpipe(serial->dev, 0),
298 				request, REQTYPE_HOST_TO_DEVICE, data[0],
299 				0, NULL, 0, 300);
300 	}
301 
302 	kfree(buf);
303 
304 	if ((size > 2 && result != size) || result < 0) {
305 		dbg("%s - Unable to send request, "
306 				"request=0x%x size=%d result=%d\n",
307 				__func__, request, size, result);
308 		return -EPROTO;
309 	}
310 
311 	/* Single data value */
312 	result = usb_control_msg(serial->dev,
313 			usb_sndctrlpipe(serial->dev, 0),
314 			request, REQTYPE_HOST_TO_DEVICE, data[0],
315 			0, NULL, 0, 300);
316 	return 0;
317 }
318 
319 /*
320  * cp210x_set_config_single
321  * Convenience function for calling cp210x_set_config on single data values
322  * without requiring an integer pointer
323  */
324 static inline int cp210x_set_config_single(struct usb_serial_port *port,
325 		u8 request, unsigned int data)
326 {
327 	return cp210x_set_config(port, request, &data, 2);
328 }
329 
330 /*
331  * cp210x_quantise_baudrate
332  * Quantises the baud rate as per AN205 Table 1
333  */
334 static unsigned int cp210x_quantise_baudrate(unsigned int baud) {
335 	if      (baud <= 56)       baud = 0;
336 	else if (baud <= 300)      baud = 300;
337 	else if (baud <= 600)      baud = 600;
338 	else if (baud <= 1200)     baud = 1200;
339 	else if (baud <= 1800)     baud = 1800;
340 	else if (baud <= 2400)     baud = 2400;
341 	else if (baud <= 4000)     baud = 4000;
342 	else if (baud <= 4803)     baud = 4800;
343 	else if (baud <= 7207)     baud = 7200;
344 	else if (baud <= 9612)     baud = 9600;
345 	else if (baud <= 14428)    baud = 14400;
346 	else if (baud <= 16062)    baud = 16000;
347 	else if (baud <= 19250)    baud = 19200;
348 	else if (baud <= 28912)    baud = 28800;
349 	else if (baud <= 38601)    baud = 38400;
350 	else if (baud <= 51558)    baud = 51200;
351 	else if (baud <= 56280)    baud = 56000;
352 	else if (baud <= 58053)    baud = 57600;
353 	else if (baud <= 64111)    baud = 64000;
354 	else if (baud <= 77608)    baud = 76800;
355 	else if (baud <= 117028)   baud = 115200;
356 	else if (baud <= 129347)   baud = 128000;
357 	else if (baud <= 156868)   baud = 153600;
358 	else if (baud <= 237832)   baud = 230400;
359 	else if (baud <= 254234)   baud = 250000;
360 	else if (baud <= 273066)   baud = 256000;
361 	else if (baud <= 491520)   baud = 460800;
362 	else if (baud <= 567138)   baud = 500000;
363 	else if (baud <= 670254)   baud = 576000;
364 	else if (baud <= 1053257)  baud = 921600;
365 	else if (baud <= 1474560)  baud = 1228800;
366 	else if (baud <= 2457600)  baud = 1843200;
367 	else                       baud = 3686400;
368 	return baud;
369 }
370 
371 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
372 {
373 	struct usb_serial *serial = port->serial;
374 	int result;
375 
376 	dbg("%s - port %d", __func__, port->number);
377 
378 	if (cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_ENABLE)) {
379 		dev_err(&port->dev, "%s - Unable to enable UART\n",
380 				__func__);
381 		return -EPROTO;
382 	}
383 
384 	/* Start reading from the device */
385 	usb_fill_bulk_urb(port->read_urb, serial->dev,
386 			usb_rcvbulkpipe(serial->dev,
387 			port->bulk_in_endpointAddress),
388 			port->read_urb->transfer_buffer,
389 			port->read_urb->transfer_buffer_length,
390 			serial->type->read_bulk_callback,
391 			port);
392 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
393 	if (result) {
394 		dev_err(&port->dev, "%s - failed resubmitting read urb, "
395 				"error %d\n", __func__, result);
396 		return result;
397 	}
398 
399 	/* Configure the termios structure */
400 	cp210x_get_termios(tty, port);
401 	return 0;
402 }
403 
404 static void cp210x_cleanup(struct usb_serial_port *port)
405 {
406 	struct usb_serial *serial = port->serial;
407 
408 	dbg("%s - port %d", __func__, port->number);
409 
410 	if (serial->dev) {
411 		/* shutdown any bulk reads that might be going on */
412 		if (serial->num_bulk_out)
413 			usb_kill_urb(port->write_urb);
414 		if (serial->num_bulk_in)
415 			usb_kill_urb(port->read_urb);
416 	}
417 }
418 
419 static void cp210x_close(struct usb_serial_port *port)
420 {
421 	dbg("%s - port %d", __func__, port->number);
422 
423 	/* shutdown our urbs */
424 	dbg("%s - shutting down urbs", __func__);
425 	usb_kill_urb(port->write_urb);
426 	usb_kill_urb(port->read_urb);
427 
428 	mutex_lock(&port->serial->disc_mutex);
429 	if (!port->serial->disconnected)
430 		cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
431 	mutex_unlock(&port->serial->disc_mutex);
432 }
433 
434 /*
435  * cp210x_get_termios
436  * Reads the baud rate, data bits, parity, stop bits and flow control mode
437  * from the device, corrects any unsupported values, and configures the
438  * termios structure to reflect the state of the device
439  */
440 static void cp210x_get_termios(struct tty_struct *tty,
441 	struct usb_serial_port *port)
442 {
443 	unsigned int baud;
444 
445 	if (tty) {
446 		cp210x_get_termios_port(tty->driver_data,
447 			&tty->termios->c_cflag, &baud);
448 		tty_encode_baud_rate(tty, baud, baud);
449 	}
450 
451 	else {
452 		unsigned int cflag;
453 		cflag = 0;
454 		cp210x_get_termios_port(port, &cflag, &baud);
455 	}
456 }
457 
458 /*
459  * cp210x_get_termios_port
460  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
461  */
462 static void cp210x_get_termios_port(struct usb_serial_port *port,
463 	unsigned int *cflagp, unsigned int *baudp)
464 {
465 	unsigned int cflag, modem_ctl[4];
466 	unsigned int baud;
467 	unsigned int bits;
468 
469 	dbg("%s - port %d", __func__, port->number);
470 
471 	cp210x_get_config(port, CP210X_GET_BAUDDIV, &baud, 2);
472 	/* Convert to baudrate */
473 	if (baud)
474 		baud = cp210x_quantise_baudrate((BAUD_RATE_GEN_FREQ + baud/2)/ baud);
475 
476 	dbg("%s - baud rate = %d", __func__, baud);
477 	*baudp = baud;
478 
479 	cflag = *cflagp;
480 
481 	cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
482 	cflag &= ~CSIZE;
483 	switch (bits & BITS_DATA_MASK) {
484 	case BITS_DATA_5:
485 		dbg("%s - data bits = 5", __func__);
486 		cflag |= CS5;
487 		break;
488 	case BITS_DATA_6:
489 		dbg("%s - data bits = 6", __func__);
490 		cflag |= CS6;
491 		break;
492 	case BITS_DATA_7:
493 		dbg("%s - data bits = 7", __func__);
494 		cflag |= CS7;
495 		break;
496 	case BITS_DATA_8:
497 		dbg("%s - data bits = 8", __func__);
498 		cflag |= CS8;
499 		break;
500 	case BITS_DATA_9:
501 		dbg("%s - data bits = 9 (not supported, using 8 data bits)",
502 								__func__);
503 		cflag |= CS8;
504 		bits &= ~BITS_DATA_MASK;
505 		bits |= BITS_DATA_8;
506 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
507 		break;
508 	default:
509 		dbg("%s - Unknown number of data bits, using 8", __func__);
510 		cflag |= CS8;
511 		bits &= ~BITS_DATA_MASK;
512 		bits |= BITS_DATA_8;
513 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
514 		break;
515 	}
516 
517 	switch (bits & BITS_PARITY_MASK) {
518 	case BITS_PARITY_NONE:
519 		dbg("%s - parity = NONE", __func__);
520 		cflag &= ~PARENB;
521 		break;
522 	case BITS_PARITY_ODD:
523 		dbg("%s - parity = ODD", __func__);
524 		cflag |= (PARENB|PARODD);
525 		break;
526 	case BITS_PARITY_EVEN:
527 		dbg("%s - parity = EVEN", __func__);
528 		cflag &= ~PARODD;
529 		cflag |= PARENB;
530 		break;
531 	case BITS_PARITY_MARK:
532 		dbg("%s - parity = MARK (not supported, disabling parity)",
533 				__func__);
534 		cflag &= ~PARENB;
535 		bits &= ~BITS_PARITY_MASK;
536 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
537 		break;
538 	case BITS_PARITY_SPACE:
539 		dbg("%s - parity = SPACE (not supported, disabling parity)",
540 				__func__);
541 		cflag &= ~PARENB;
542 		bits &= ~BITS_PARITY_MASK;
543 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
544 		break;
545 	default:
546 		dbg("%s - Unknown parity mode, disabling parity", __func__);
547 		cflag &= ~PARENB;
548 		bits &= ~BITS_PARITY_MASK;
549 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
550 		break;
551 	}
552 
553 	cflag &= ~CSTOPB;
554 	switch (bits & BITS_STOP_MASK) {
555 	case BITS_STOP_1:
556 		dbg("%s - stop bits = 1", __func__);
557 		break;
558 	case BITS_STOP_1_5:
559 		dbg("%s - stop bits = 1.5 (not supported, using 1 stop bit)",
560 								__func__);
561 		bits &= ~BITS_STOP_MASK;
562 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
563 		break;
564 	case BITS_STOP_2:
565 		dbg("%s - stop bits = 2", __func__);
566 		cflag |= CSTOPB;
567 		break;
568 	default:
569 		dbg("%s - Unknown number of stop bits, using 1 stop bit",
570 								__func__);
571 		bits &= ~BITS_STOP_MASK;
572 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
573 		break;
574 	}
575 
576 	cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
577 	if (modem_ctl[0] & 0x0008) {
578 		dbg("%s - flow control = CRTSCTS", __func__);
579 		cflag |= CRTSCTS;
580 	} else {
581 		dbg("%s - flow control = NONE", __func__);
582 		cflag &= ~CRTSCTS;
583 	}
584 
585 	*cflagp = cflag;
586 }
587 
588 static void cp210x_set_termios(struct tty_struct *tty,
589 		struct usb_serial_port *port, struct ktermios *old_termios)
590 {
591 	unsigned int cflag, old_cflag;
592 	unsigned int baud = 0, bits;
593 	unsigned int modem_ctl[4];
594 
595 	dbg("%s - port %d", __func__, port->number);
596 
597 	if (!tty)
598 		return;
599 
600 	tty->termios->c_cflag &= ~CMSPAR;
601 	cflag = tty->termios->c_cflag;
602 	old_cflag = old_termios->c_cflag;
603 	baud = cp210x_quantise_baudrate(tty_get_baud_rate(tty));
604 
605 	/* If the baud rate is to be updated*/
606 	if (baud != tty_termios_baud_rate(old_termios) && baud != 0) {
607 		dbg("%s - Setting baud rate to %d baud", __func__,
608 				baud);
609 		if (cp210x_set_config_single(port, CP210X_SET_BAUDDIV,
610 					((BAUD_RATE_GEN_FREQ + baud/2) / baud))) {
611 			dbg("Baud rate requested not supported by device\n");
612 			baud = tty_termios_baud_rate(old_termios);
613 		}
614 	}
615 	/* Report back the resulting baud rate */
616 	tty_encode_baud_rate(tty, baud, baud);
617 
618 	/* If the number of data bits is to be updated */
619 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
620 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
621 		bits &= ~BITS_DATA_MASK;
622 		switch (cflag & CSIZE) {
623 		case CS5:
624 			bits |= BITS_DATA_5;
625 			dbg("%s - data bits = 5", __func__);
626 			break;
627 		case CS6:
628 			bits |= BITS_DATA_6;
629 			dbg("%s - data bits = 6", __func__);
630 			break;
631 		case CS7:
632 			bits |= BITS_DATA_7;
633 			dbg("%s - data bits = 7", __func__);
634 			break;
635 		case CS8:
636 			bits |= BITS_DATA_8;
637 			dbg("%s - data bits = 8", __func__);
638 			break;
639 		/*case CS9:
640 			bits |= BITS_DATA_9;
641 			dbg("%s - data bits = 9", __func__);
642 			break;*/
643 		default:
644 			dbg("cp210x driver does not "
645 					"support the number of bits requested,"
646 					" using 8 bit mode\n");
647 				bits |= BITS_DATA_8;
648 				break;
649 		}
650 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
651 			dbg("Number of data bits requested "
652 					"not supported by device\n");
653 	}
654 
655 	if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) {
656 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
657 		bits &= ~BITS_PARITY_MASK;
658 		if (cflag & PARENB) {
659 			if (cflag & PARODD) {
660 				bits |= BITS_PARITY_ODD;
661 				dbg("%s - parity = ODD", __func__);
662 			} else {
663 				bits |= BITS_PARITY_EVEN;
664 				dbg("%s - parity = EVEN", __func__);
665 			}
666 		}
667 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
668 			dbg("Parity mode not supported "
669 					"by device\n");
670 	}
671 
672 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
673 		cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
674 		bits &= ~BITS_STOP_MASK;
675 		if (cflag & CSTOPB) {
676 			bits |= BITS_STOP_2;
677 			dbg("%s - stop bits = 2", __func__);
678 		} else {
679 			bits |= BITS_STOP_1;
680 			dbg("%s - stop bits = 1", __func__);
681 		}
682 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
683 			dbg("Number of stop bits requested "
684 					"not supported by device\n");
685 	}
686 
687 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
688 		cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
689 		dbg("%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
690 				__func__, modem_ctl[0], modem_ctl[1],
691 				modem_ctl[2], modem_ctl[3]);
692 
693 		if (cflag & CRTSCTS) {
694 			modem_ctl[0] &= ~0x7B;
695 			modem_ctl[0] |= 0x09;
696 			modem_ctl[1] = 0x80;
697 			dbg("%s - flow control = CRTSCTS", __func__);
698 		} else {
699 			modem_ctl[0] &= ~0x7B;
700 			modem_ctl[0] |= 0x01;
701 			modem_ctl[1] |= 0x40;
702 			dbg("%s - flow control = NONE", __func__);
703 		}
704 
705 		dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
706 				__func__, modem_ctl[0], modem_ctl[1],
707 				modem_ctl[2], modem_ctl[3]);
708 		cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
709 	}
710 
711 }
712 
713 static int cp210x_tiocmset (struct tty_struct *tty, struct file *file,
714 		unsigned int set, unsigned int clear)
715 {
716 	struct usb_serial_port *port = tty->driver_data;
717 	return cp210x_tiocmset_port(port, file, set, clear);
718 }
719 
720 static int cp210x_tiocmset_port(struct usb_serial_port *port, struct file *file,
721 		unsigned int set, unsigned int clear)
722 {
723 	unsigned int control = 0;
724 
725 	dbg("%s - port %d", __func__, port->number);
726 
727 	if (set & TIOCM_RTS) {
728 		control |= CONTROL_RTS;
729 		control |= CONTROL_WRITE_RTS;
730 	}
731 	if (set & TIOCM_DTR) {
732 		control |= CONTROL_DTR;
733 		control |= CONTROL_WRITE_DTR;
734 	}
735 	if (clear & TIOCM_RTS) {
736 		control &= ~CONTROL_RTS;
737 		control |= CONTROL_WRITE_RTS;
738 	}
739 	if (clear & TIOCM_DTR) {
740 		control &= ~CONTROL_DTR;
741 		control |= CONTROL_WRITE_DTR;
742 	}
743 
744 	dbg("%s - control = 0x%.4x", __func__, control);
745 
746 	return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
747 }
748 
749 static int cp210x_tiocmget (struct tty_struct *tty, struct file *file)
750 {
751 	struct usb_serial_port *port = tty->driver_data;
752 	unsigned int control;
753 	int result;
754 
755 	dbg("%s - port %d", __func__, port->number);
756 
757 	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
758 
759 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
760 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
761 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
762 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
763 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
764 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
765 
766 	dbg("%s - control = 0x%.2x", __func__, control);
767 
768 	return result;
769 }
770 
771 static void cp210x_break_ctl (struct tty_struct *tty, int break_state)
772 {
773 	struct usb_serial_port *port = tty->driver_data;
774 	unsigned int state;
775 
776 	dbg("%s - port %d", __func__, port->number);
777 	if (break_state == 0)
778 		state = BREAK_OFF;
779 	else
780 		state = BREAK_ON;
781 	dbg("%s - turning break %s", __func__,
782 			state == BREAK_OFF ? "off" : "on");
783 	cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
784 }
785 
786 static int cp210x_startup(struct usb_serial *serial)
787 {
788 	/* cp210x buffers behave strangely unless device is reset */
789 	usb_reset_device(serial->dev);
790 	return 0;
791 }
792 
793 static void cp210x_disconnect(struct usb_serial *serial)
794 {
795 	int i;
796 
797 	dbg("%s", __func__);
798 
799 	/* Stop reads and writes on all ports */
800 	for (i = 0; i < serial->num_ports; ++i)
801 		cp210x_cleanup(serial->port[i]);
802 }
803 
804 static int __init cp210x_init(void)
805 {
806 	int retval;
807 
808 	retval = usb_serial_register(&cp210x_device);
809 	if (retval)
810 		return retval; /* Failed to register */
811 
812 	retval = usb_register(&cp210x_driver);
813 	if (retval) {
814 		/* Failed to register */
815 		usb_serial_deregister(&cp210x_device);
816 		return retval;
817 	}
818 
819 	/* Success */
820 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
821 	       DRIVER_DESC "\n");
822 	return 0;
823 }
824 
825 static void __exit cp210x_exit(void)
826 {
827 	usb_deregister(&cp210x_driver);
828 	usb_serial_deregister(&cp210x_device);
829 }
830 
831 module_init(cp210x_init);
832 module_exit(cp210x_exit);
833 
834 MODULE_DESCRIPTION(DRIVER_DESC);
835 MODULE_VERSION(DRIVER_VERSION);
836 MODULE_LICENSE("GPL");
837 
838 module_param(debug, bool, S_IRUGO | S_IWUSR);
839 MODULE_PARM_DESC(debug, "Enable verbose debugging messages");
840